Interventional Nephrology Guidelines for Dialysis Access and Kidney Biopsy

Internal review

• The entire panel conducted the internal review of the guidelines (including national and international experts) on December 15^th, 2023, for further critical comments, suggestions, and approval.

• Each section of the guidelines was appraised by the deputed panel to ensure that the information was scientifically accurate, up to date with current practices, and relevant to the Indian healthcare context.

• Feedback from the internal review process was incorporated into the guidelines. Discussions among the core team resolved any discrepancies or conflicting recommendations. The final draft was prepared for public review.

External (public) review

• A public review period was initiated in June 2024, inviting broader participation.

• The revised and updated recommendations were compiled as a draft manuscript and uploaded to the AVATAR foundation website for external public review and approval by all workgroups and other panel members.

• The evaluation criteria included scientific accuracy, clinical relevance, clarity of recommendations, and applicability to the Indian healthcare setting.

• Detailed feedback and recommendations were submitted as a revised document with comments on specific sections or individual recommendations.

• The feedback was carefully considered to ensure that all perspectives were accounted for in the final version of the guidelines.

• The revised guidelines underwent a final approval process by the AVATAR Foundation leadership, incorporating all necessary revisions, after which the final manuscript was submitted for publication.

Rationale

The timely referral of patients with advanced CKD requiring HD for VA creation is critical to the success of the treatment.¹² There are three main types of VA: an AVF, an AVG, and a catheter. An AVF is considered the best type of VA as it has the least complications and provides better blood flow and dialysis adequacy, thus improving survival and reducing hospitalizations.¹³ However, an AVF takes several weeks to months to mature and heal before it can be used for dialysis. Therefore, planning and creating an AVF is critical before the patient requires dialysis. While an AVG does not require maturation time, depending on the type of graft, a two to three-week post-implantation period may be needed before needling to ensure that the graft has integrated into the tissues.¹²

While no RCTs have specifically compared the consequences of early and late referrals for dialysis preparation, 27 longitudinal cohort studies have shown that earlier referral is associated with reduced mortality and hospitalization rates, greater adoption of PD, lower chance of needing temporary VA at the initiation of dialysis, and an increased likelihood of maintaining an AVF.¹⁴

Ideally, planning for VA should commence after CKD stage IV. The optimal timing for referring a patient with advanced CKD for VA surgery, especially in rapidly declining kidney conditions like advanced diabetic kidney disease or RPGNs, depends on several factors, such as the patient's preference, comorbidities, etiology of CKD, rate of decline in kidney function, and local surgical expertise.¹⁵ According to the KDOQI Clinical Practice Guideline for Vascular Access, patients with advanced CKD should be referred for VA surgery when their eGFR is < 30 mL/min/1.73 m² or they are expected to need dialysis within a year.³ This recommendation is based on the notion that early referral can increase the likelihood of having a functional AVF during dialysis initiation, thus improving clinical outcomes and reducing complications. ESVS recommends that a native AVF be created six months before HD inititation.⁴ Spanish society suggests that a prosthetic AVG be created 3 to 6 weeks before HD initiation.⁵ However, this recommendation should be tailored to each patient's situation and care goals. Creating access far ahead of the need may lead to unwarranted surgeries and procedures. Current practice varies by region and timing of referral to a nephrologist. Nearly four out of five patients start dialysis with a catheter.

Based on the literature, a 6-month timeline before the anticipated demand for dialysis would be reasonable, provided a successful access creation program is locally available. Pre-dialysis fistula creation will allow sufficient time for surgery and maturation of an AVF, the preferred type of VA for HD. Pre-emptive AVF creation will also negate the potential exhaustion of fistula-suitable veins from frequent venipuncture in critically ill patients.

Rationale

Many dialysis patients, such as older patients or those with diabetes, peripheral arterial obstructive disease (PAOD), or coronary artery disease, have weak vasculature for AVF creation, which could explain the high primary failure and modest long-term patency of the AVF.¹⁶ Reportedly, AVFs have a high failure rate, estimated at 0.2 occurrences per patient per year,¹⁷ with native AVF primary failure rate ranging between 20% to 60%.¹⁸

Preoperative evaluation, including clinical history, physical examination, and imaging studies, specifically ultrasonography, has demonstrated that improved planning resulted in better postoperative functional AVFs and reduced primary failure rates.^18-26

The KDOQI guidelines recommend that the initial assessment for creating VA should involve a physical examination concentrating on vascular anatomy.²⁷ Based on low-quality evidence from non-American studies with varying outcome measures, they now suggest selective preoperative ultrasound for patients at high risk of AV access failure instead of routine vascular mapping for all patients.^3,25,28 In contrast, the European, UK, and Spanish guidelines continue to include routine preoperative evaluation for all patients.^4,5,29 The Spanish Society guidelines recommend that the decision be based on a comprehensive evaluation encompassing the patient's clinical history, a physical examination of the vasculature, preoperative ultrasound, and the patient's personal preferences.⁵

European recommendations include preoperative ultrasonography of bilateral upper extremity arteries and veins for all patients planning VA creation, with additional central vein imaging for those with previous central vein catheters.⁴ Similarly, UK guidelines advise imaging to rule out CVS in patients with a history of central venous cannulation.²⁹

Altogether, it is recommended that vascular mapping be performed before access creation to ensure successful outcomes of a functioning AVF, considering clinical needs. This approach reduces prolonged dependence on HD catheters and associated complications.

Rationale

Venous preservation should be part of the future VA plan for individuals with progressing CKD.^27,30 Dialysis access is ideally constructed in the patient’s non-dominant hand. One significant barrier in its constructing is an unsuitable peripheral artery and vein or central vein. Patients with CKD, particularly those who are elderly, diabetic, or have PAOD or coronary artery disease, face a high likelihood of requiring recurrent venipunctures, CVC, arterial treatments, and cardiac devices. The insertion of medical devices can cause infections and endothelial injury, leading to CVS or occlusion, which can hinder the formation of an AVF. Therefore, it is crucial to preserve these vessels, especially when patients reach CKD stage IV or even at earlier stages.

The most common causes of CVS in CKD patients are PICC lines, CVCs, midline catheters, and cardiac rhythm devices with transvenous leads.^31-34 Transvenous pacing lead insertion through the subclavian vein (SVC) on either side leads to CVS in 25-64% of the patients.^35-39 Signs and symptoms of this stenosis may manifest after AV access construction in the ipsilateral limb.

To ensure the effective establishment of a functioning AVF, it is recommended that vessel preservation measures be incorporated as an integral component of pre-dialysis CKD therapy. Additionally, pre-emptive AVF creation in patients with advanced CKD, who may be admitted to an ICU before dialysis, will help avoid the probable exhaustion of fistula-suitable veins due to recurrent venipuncture.

Some of the steps that could be performed to preserve vessels include:

• 1.

  For blood drawing, using veins on the back of the hand or the forearm, as utilizing the forearm cephalic vein, especially at the elbow, can induce venous damage and phlebitis, resulting in the loss of a segment commonly used to create an AVF.

• 2.

  Veins in the wrist and elbow should be preserved for fistula creation.

• 3.

  Develop institutional policies to govern the use of midline and PICC catheters in patients with advanced CKD.

• 4.

  Pacing lead-induced stenosis is often challenging to manage and frequently recurs after an angioplasty. Therefore, it is advisable to consider alternatives, such as epicardial lead pacemakers, subcutaneous lead automatic implantable cardioverter defibrillator, or leadless pacemakers,⁴⁰ in patients with advanced CKD on HD.

Rationale

An unplanned dialysis is any patient receiving unanticipated dialysis regardless of location or previous referral status to nephrologists. The majority of unplanned dialyses are initiated in hospitalized patients. Cardiac failure and strokes are independently associated with the urgent start of dialysis.⁴¹ The access options for such situations are limited and depend on understanding the patient's condition. The most common access options in such situations are a non-tunneled dialysis catheter, a TCC, early cannulation prosthetic AVG, and urgent start PD. While feasible, the latter two options have many logistical demands. Placement of an immediate-use early cannulation AVG depends on the availability, accelerated pre-surgical optimization, suitable vessel characteristics, skilled surgeons, operating room availability, and trained dialysis nurses with skills to cannulate immediately post-surgery.⁴² Early cannulation AVG placement should only be considered when lacking suitable veins for fistula creation. Urgent start PD is another effective and appropriate alternative to TCC.⁴³ It has similar limitations to an immediate-use AVG. Many patients with unplanned dialysis initiation may not be ideal for chronic PD therapy.

Given these challenges to current alternatives, catheters are preferred because they can be used in virtually any patient, are easily placed, and ready for immediate use after insertion. n-TCCs are primarily used in acute situations due to their rapid placement, the ability to be inserted at bedside without tunneling, and minimal trauma, making them highly effective in emergencies. In contrast, TCCs are typically used for long-term or permanent VA.⁴⁴ UK guidelines advise avoiding n-TCCs due to a heightened risk of sepsis, with current recommendations restricting their duration to no more than 1 week when placed in the internal jugular or femoral vein.^29,45,46 TCC, on the other hand, is more complex and requires imaging for placement. It is recommended over n-TCC because it has fewer complications and can tolerate higher flows.

Spanish society guidelines and KDOQI acknowledge this cohort of patients and recommend tunneled dialysis catheters as the initial access if they are not being considered for urgent PD.^3,5,45 PD may be favored in cases of hemodynamic instability, difficult VA, or bleeding disorders, while HD might be more suitable for long-term use or where PD is contraindicated due to abdominal issues. KDOQI strongly advocates access plan development within 30 days.³ In summary, it is reasonable for patients with unplanned or urgent dialysis to receive a tunneled dialysis catheter as the initial access. An access creation plan is strongly recommended before patient discharge.

Rationale

Monitoring complications in HD VA involves direct clinical examination or device-derived surveillance methods. According to the 2019 update of the National Kidney Foundation (NKF's) KDOQI Clinical Practice Guidelines for VA, clinical monitoring is recommended as the standard practice for detecting and addressing stenosis. This helps minimize or prevent dialysis interruptions and reduces thrombosis rates.³ Clinical monitoring primarily relies on periodically observed clinical findings before each dialysis session. It is important to note that clinical monitoring lacks standardization across different personnel (such as nurses and technicians), dialysis centers, and countries. Moreover, significant interpersonal and intrapersonal variability has not been thoroughly investigated. Studies evaluating physical examinations to identify dysfunctional access performed in the context of existing clinical indicators are few.^47-49 The statistical value and role of non-physician personnel in dialysis units are lacking. Failure to promptly identify dysfunctional accesses can result in complications such as aneurysmal degeneration, thrombosis, and potentially catastrophic outcomes like spontaneous rupture and mortality. Effective clinical monitoring strategies require a dedicated, trained team to be available seven days a week. Surveillance methodologies are based on flow and pressures. These two parameters could be influenced by needle size and dialysis prescription. While ultrasound could serve monitoring and diagnostic purposes, trained personnel and cost are hurdles for widespread adaptation. India lacks evidence on the utility of surveillance methodologies in VA care. We cannot guide using surveillance methodologies other than physical examination and clinical parameters to identify dysfunctional dialysis access.

Rationale

All CKD patients should ideally commence dialysis with a mature AVF created well before anticipated dialysis initiation. In reality, due to a combination of factors, most patients start dialysis with either temporary or tunneled catheters. Temporary catheters carry a higher risk of infection and attendant complications and should not be used for longer than a week.⁴⁶ If the patient is relatively stable, dialysis should be initiated after inserting a TCC. If the use of a temporary catheter cannot be avoided, then it must be changed to a TCC as early as possible. Past guidelines emphasized AVF as the best access for most patients based on the twin risks of bloodstream infections and association with mortality.²⁷ Of late, there has been a growing understanding that the quality of evidence used to come to these conclusions has been low and that the studies were biased.³ A high rate of AVFs that do not mature and necessitate a dialysis catheter could be an unintended outcome of this emphasis.^50,51 Especially in older individuals aged > 80 years, the mortality benefit of AV access over TCC is inconsistent.⁵² Hence, while TCC avoidance and TCC minimization should be guiding factors in most patients, it must also be appreciated that the TCC may be the most appropriate access for a significant proportion given their medical and social circumstances.⁵³

Rationale

The use of TCCs is recommended for children with stage V CKD in specific clinical scenarios where other forms of dialysis access are either impractical or not immediately available. TCCs are a durable and long-lasting option for VA, making them suitable for children who require dialysis for extended periods and can be used for both HD and PD, providing flexibility in treatment options. Compared to other types of VAs, TCCs are less prone to thrombosis, which can be a significant complication in children.

For children weighing < 20 kg who require dialysis for > 1 week, TCCs provide a reliable alternative when a native AVF is not feasible due to clinical factors such as delayed AVF maturation or complex comorbidities. Additionally, for children awaiting kidney transplantation, where AVF creation is deemed challenging due to their size, weight, or limited surgical expertise, TCCs offer a safe and effective option. In emergencies, such as when children with ESKD "crash land" into urgent HD, TCCs allow for rapid initiation of dialysis. Furthermore, for children planning to transition to PD but unable to begin immediately, TCCs can serve as an essential temporary access point. These guidelines ensure that children receive the most appropriate dialysis access based on their unique clinical needs, minimizing complications and ensuring optimal treatment outcomes.

Rationale

Though temporary dialysis catheters should be the last option for VA, they may be lifesaving in certain situations. A complication with an existing AV access that may take up to two weeks to resolve (for example, a minor infiltration) often necessitates the insertion of a temporary dialysis catheter. Any situation, like fluid overload or refractory hyperkalemia without a functioning AV access (thrombosed or not created), in which an ESKD patient presents with an urgent indication for dialysis, requires the use of a temporary dialysis catheter.³ While the right IJV is the preferred locale for inserting a temporary dialysis catheter, the femoral vein may be more convenient in some situations, e.g., an acutely orthopneic patient unable to lie down or the presence of coagulopathy. Over short periods, the risk of infection may be similar in catheters inserted in the internal jugular and femoral veins.⁵⁴ The SVCs must be avoided because of the high risk of CVS.⁵⁵ Financial constraints and lack of availability of expertise for TCC insertion are valid reasons to opt for a temporary dialysis catheter.⁵⁶

Rationale

Despite the disadvantages associated with long-term use and efforts to reduce its use, TCC continues to be the global VA of choice in 10-15 % of dialysis patients.^57,58 Amongst the choices of sites, the NKF-KDOQI clinical practice guidelines recommend using the right IJV as the preferred route for HD catheters, due to its ease of identification, large size, unobstructed straight passage to the right atrium, and lower complication rates.^59,60

When the right IJV is unavailable for TCC placement, the choice of secondary access varies. Traditionally, both SVCs and the left IJV have been used, but several studies indicate that these routes are associated with higher rates of procedural complications, central stenosis, and thrombosis.^61,62

The right EJV has also been explored as an access route for HD and non-dialysis CVCs.^63-65 Its advantages include a relatively direct course, a superficial location, and comparable blood flow to the IJV. A retrospective observational study has suggested that the right EJV may offer superior cumulative patency and catheter removal rates compared to the left IJV as an alternative insertion site for TCCs.⁶⁶

The femoral catheters are to be considered when neck vessels are exhausted in special scenarios. Recent systematic reviews have shown comparable CRBSI rates between femoral and neck vessels.⁶⁷ The subclavian vessels are considered the last choice for TCC insertion due to the higher incidence of CVS and the impediment it causes to the development of ipsilateral upper limb AVF.^61,62 The data on TCC insertions in left EJV, lumbar veins, collateral veins, and IVC are anecdotal and can be used as a last resort by expert operators.

Rationale

The major disadvantages of using TCC as long-term access in dialysis patients are infections, including CBRSIs, exit site infections, and tunnel infections, which contribute to a significant reduction in catheter survival time. Staphylococcus aureus and MRSA are common pathogens responsible for central-line associated blood-stream infection (CLABSI). Preventing CLABSI can significantly reduce morbidity, mortality, and healthcare costs associated with these infections. Early identification and decolonization can lead to better patient outcomes and reduce the burden on healthcare resources.

Measures to reduce them include optimal skin preparation and prophylactic use of intravenous antibiotics and antibiotic lock solutions. Hair should be removed at the insertion site using clippers (not shaving) before applying antiseptics, to help improve dressing adherence.⁶⁸ Studies comparing chlorhexidine-containing antiseptic regimens with povidone-iodine or alcohol during intravascular catheter insertion have consistently shown lower rates of catheter colonization or CRBSI associated with chlorhexidine preparations.^69,70 In a well-designed three-armed study comparing 2% aqueous chlorhexidine gluconate, 10% povidone-iodine, and 70% alcohol, chlorhexidine gluconate demonstrated a higher tendency to reduce CRBSI compared to povidone-iodine or alcohol.⁶⁹ A meta-analysis of 4,143 catheters suggested that chlorhexidine preparation reduced the risk of CRI by 49% (95% CI .28% to .88%) compared to povidone-iodine.⁷¹

While chlorhexidine has become the standard antiseptic for skin preparation for inserting central and peripheral venous catheters, a 5% povidone-iodine solution in 70% ethanol significantly reduced CVC-related colonization and infection compared to 10% aqueous povidone-iodine.⁷²

Similarly, QACs, such as PHMB, are also widely used for skin preparation before catheter insertion or change due to their effective antimicrobial properties.^73,74 PHMB acts by disrupting the microbial cell membranes, thereby reducing the risk of infections at the insertion site.⁷⁴ It is known for its broad spectrum of activity against bacteria, fungi, and some viruses, making it suitable for maintaining skin integrity and reducing the microbial load before medical procedures.⁷⁴ Performing nasal and perineal swabs can identify colonization with bacteria, allowing for targeted skin decolonization measures. This approach helps prevent CRI and promotes patient safety during invasive procedures.

Rationale

Although TCCs offer several advantages over AVF, such as quick and painless connection, the biggest disadvantage is the higher rate of infection, the major reason for KDOQI’s recommendation for AVF as the first choice of VA.³ Using TCCs instead of n-TCCs reduces the risk of infection. The long subcutaneous tunnels and reendothelialization of cuffs create a barrier that prevents organisms from migrating from the entry site. Other strategies to lower the incidence of CRBSIs include applying topical antimicrobial ointments or dressings to entry sites and using antimicrobial locking solutions.⁷⁵ The prophylactic usage of antibiotics is widely practiced despite conflicting evidence for the same.⁷⁶ Unlike surgical interventions where prophylaxis with antibiotics has been established to have a protective role, minimally invasive dialysis access interventions are at low risk of infections. Further, the cost, allergies, toxicities, and emergence of antibiotic resistance put into question the need for antibiotic prophylaxis.

In 2011, the Centre for Disease Control advised against the routine use of systemic antimicrobial prophylaxis before catheter insertion as part of their guideline for preventing intravascular CRI.⁷⁷ Additionally, a 2013 Cochrane systematic review evaluating the effectiveness of antibiotic prophylaxis in preventing gram-positive infections in oncology patients with central access found no significant benefit.⁷⁸ More recently, a study by Reidy et al. concisely demonstrated that antimicrobial prophylaxis does not provide a benefit in preventing CRI following CVC insertion.⁷⁹

Rationale

n-TCCs for HD are inserted bedside, whereas TCC insertions are usually carried out with USG and fluoroscopic guidance for puncture and tip positioning, respectively. Radiologically guided insertions have been found to decrease acute complications and result in long-term safety.^3,77 The use of sterile zones (intervention suites/OR) ensures maximum sterile precautions thereby reducing catheter infections.

Bedside insertions of TCC have been considered in carefully selected patient populations, including critically ill patients and situations with cost constraints and/or infrastructure logistics. During the COVID-19 pandemic, several reports of bedside insertion of TCC in the right IJV have been documented with minimal procedure-related complications and correct tip positioning.^80,81 However, the application of the same to the general dialysis population needs further research.

Rationale

Traditionally, CVCs were placed blindly using anatomical landmarks, viz. vessel pulsations, the expected location of the vein in relation to the accompanying artery, etc. The common sites included the internal jugular, subclavian, and femoral veins. Whilst experienced operators using the landmark method can achieve relatively high success rates with few complications, failure rates for initial CVC insertion have been reported to be as high as 35%.⁸² More recently, image guidance with ultrasound, fluoroscopy, or both has been used during insertions, with the advantages being high success rates and reduced complications, especially related to arterial punctures and pneumothorax.

Reports have shown significant variations between the IJV and carotid artery anatomy and such variations can result in inadvertent arterial puncture with the landmark method.^83-86 In a study involving 143 patients with prior HD catheter placement, 26% were found to have jugular vein thrombosis, with 62% of these cases being occlusive.⁸⁷ In other reports, ultrasound examination reported complete thrombosis of IJV in 18% of patients on dialysis. In such cases imaging allows a trained operator to localize the target vein and target skin puncture site while avoiding aberrant anatomy.^82,88 Therefore, the use of USG guidance is recommended when placing CVCs.

In a single-center RCT with 110 participants, comparing USG with traditional landmark-guided insertion of uncuffed femoral vein dialysis catheters, the USG group demonstrated significantly higher success rates (98% vs. 80%; P = 0.002) in achieving successful CVC insertion within three attempts compared to the landmark group.⁸⁹ Additionally, the USG group showed higher success rates on the first attempt (86% vs. 55%; P < 0.001), required fewer attempts for successful catheterization (mean of 1.16 vs. 1.51; P = 0.001), and experienced fewer complications like hematoma or arterial puncture (5.5% vs. 18.2%; P = 0.04).

A comprehensive Cochrane review discussed a meta-analysis by Rabindranath et al., which included 7 RCTs comprising 767 patients with 830 CVC insertions. Key findings included a significantly reduced risk of overall CVC placement failure (7 studies/830 catheters, RR: 0.11; 95% CI, 0.03 to 0.35), first-attempt failure (5 studies/705 catheters, RR: 0.40; 95% CI, 0.03 to 0.52), arterial perforation (6 studies/785 CVC, RR: 0.22; 95% CI, 0.06 to 0.81), hematoma formation (4 studies/323 CVC; RR: 0.27; 95% CI, 0.08 to 0.88), and pneumothorax or haemothorax (5 studies/675 CVC, RR: 0.23; 95% CI, 0.04 to 1.38). The study also reported a reduced time required for successful cannulation (mean difference –1.40 min; 95% CI, –2.17 to –0.63) and fewer insertion attempts per CVC (mean difference –0.35; 95% CI, –0.54 to –0.16).⁹⁰

The differences were statistically significant for all analyzed variables except for the incidence of pneumothorax and haemothorax. This makes USG-guided placements a technically and clinically better option as compared to blind techniques based on landmarks. A subsequent Cochrane systematic review on IJV catheter insertions corroborated these findings and concluded that the doppler ultrasound does not provide additional benefits over the conventional ultrasound.⁹¹

According to guidelines by the 2002 National Institute for Clinical Excellence, USG should be the preferred method for inserting CVCs into the IJV across different clinical scenarios for adults and children, whether in elective or emergency settings.⁹² The recommendation was based on results from seven RCTs, which indicated that real-time USG significantly outperformed the landmark method across all measured outcome variables for IJV insertions in adults. Compared to the landmark method, USG was associated with reduced risks of failed catheter placements (86% reduction in RR, 95% CI 67% to 94%, p < 0.001), fewer catheter placement complications (57% reduction in RR, 95% CI 13% to 78%, p = 0.02), and decreased likelihood of failure on the first catheter placement attempt (41% reduction in RR, 95% CI 12% to 61%, p = 0.009). It also required fewer attempts to achieve successful catheterization (on average, 1.5 fewer attempts, 95% CI 0.47 to 2.53, p = 0.004). These RCTs have included all central venous lines, including dialysis lines, allowing us to extrapolate the same to TCCs.

Rationale

Fluoroscopy uses X-rays to obtain real-time dynamic images, allowing direct visualization of the guidewire, which often must negotiate angulation or stenosis. Venous stenosis and angulations are very common, particularly in patients with a prior history of central vein cannulations, and may complicate blind insertions.^93,94 The guidewire may pass aberrantly into the azygous vein, the SVCs, the opposite brachiocephalic vein, or even upwards into the jugular vein with consequent difficulties in CVC placement. Tip positioning, which is very critical for good flows, can also be visualized using real-time fluoroscopy. Catheter malposition occurs frequently (25 to 40%) when fluoroscopy is not utilized for guidance. Fluoroscopy can achieve accurate catheter positioning in 95 to 100% of cases.⁹⁵ Fluoroscopy also provides direct imaging of wires and dilators, reducing the risk of injury. In a retrospective study involving 532 tunneled internal jugular HD catheters, positioning the catheter tip within the right atrium rather than the superior vena cava was associated with reduced catheter dysfunction, particularly notable for left-sided catheters.⁹⁶ Fluoroscopy appears effective in reducing misplacements. Another retrospective study of 202 catheter insertions found that fluoroscopy was linked to decreased catheter misplacement (OR 0.13, 95% CI 0.02-0.71), with this benefit potentially more pronounced for left-sided catheters. There was a significantly higher success rate (defined as placement and use of the CVC with adequate blood flow) with fluoroscopy (98% vs. 92%; P = 0.03). The study found a significantly higher success rate (98% vs. 92%; P = 0.03) for placement and use of the CVC with adequate blood flow when fluoroscopy was utilized. No significant difference was observed between the fluoroscopy-guided and non-guided groups regarding major, minor, or total bleeding events. The total bleeding rate was 1.5% in the fluoroscopy-guided group and 3.0% in the non-guided group.⁸⁸

In a separate retrospective study of 104 catheters inserted without fluoroscopy, tip malposition (specifically in the brachiocephalic or azygous vein) occurred in 6 out of 20 TCCs inserted on the left side, and none in the 68 inserted on the right side.⁹⁷ There are case reports demonstrating a series of successful TCC insertions on the right side without fluoroscopy. In a study by Motta Elias et al.,⁹⁸ 130 cases of right internal jugular TCC insertions were done by converting the existing non-cuffed dialysis catheters to TCCs. A technical success rate of 100% was reported, with no immediate post-procedural complications. Other studies have documented blind TCC placements without fluoroscopy, with high success rates and very low complication rates.^80,99 In a retrospective study by Chang et al., 124 cases of blind TCC insertions only with USG guidance without fluoroscopy were comparable to 480 cases of fluoroscopy-guided placements in terms of success rates and complications.⁹⁹ However, only two cases (1.6%) of left-sided TCC were performed among the 124 cases done without fluoroscopy. Sohail et al., in a series of 25 COVID patients, reported safe placements of right jugular TCC at the bedside without fluoroscopy.⁸⁰ Though the series primarily looked at COVID patients in the ICU and the bedside placements were done mainly for COVID concerns, the same could be extrapolated to resource-limited settings where fluoroscopy is not readily available.

Therefore, fluoroscopy demonstrates clear advantages, particularly with left-sided insertions, and has become the standard practice for all catheter insertions in many healthcare units.

Rationale

Although an AVF is the ideal access for long-term dialysis, most patients start dialysis with a catheter, and a substantial proportion continue to use a TCC for permanent access.¹⁰⁰ Exhaustion of vessels amenable for AV access creation, lack of maturation of successive AV accesses, patients with very poor cardiac function, limited life expectancy of < 1 year, and patient preference are the usual situations where TCCs are used for permanent access. TCCs used over long periods are prone to uncommon complications like adhesion of the TCCs to the venous walls, embolization of parts, or perforation through the vessel wall.¹⁰¹ Rigidly adherent catheters, also called stuck catheters and retained or embolized parts of TCCs can necessitate endovascular or open surgical procedures to remove the catheters or their parts.^102,103 However, there are no studies that have addressed the ideal length of time for which TCCs can be used. Considering that these complications are rare and that change of TCCs comes with its procedural risks and costs, we believe that there should be no upper limit to the duration for which a TCC can be used. On the other hand, periodic evaluation must be undertaken to determine whether the creation of more durable access is possible.³

Rationale

The “optimal” positioning of a chronic dialysis catheter tip has been a subject of longstanding debate, with conflicting recommendations from various organizations such as the US Food and Drug Administration and the KDOQI.^104,105 With the ever-increasing numbers of ESKD patients needing dialysis and catheters being the most used access for incident dialysis patients, it is no surprise that an agreement for the TCC tip position is of paramount importance. Till 2006, the KDOQI guidelines recommended placing the dialysis catheter tip in the superior vena cava to “not cause cardiac perforations”.^106,107 Due to the updated practices including the use of USG and fluoroscopy in most units and the evolution of catheter designs and materials, the risk of cardiac and venous perforation has significantly decreased.^108-111 The recent recommendations in the KDOQI and the Spanish guidelines recommend that the tip be placed in the mid-RA for optimal functioning.^3,5

TCC tip should be in the mid-RA for adequate flows and to avoid vessel and right atrial trauma and complications. Proximal locations (cavo-atrial junction or above) may favor fibrin sheath formation, and distal locations may lead to complications like arrhythmias, tricuspid regurgitation, or IVC stenosis.³ The length of the TCC (cuff to tip length) should be sufficient for the tip to reach mid-RA. Placement of the catheter tip in the RA reduces the risk of trauma-induced venous stenosis from repeated tapping during HD and minimizes the formation or progression of the fibrin sheath.^112,113 It is crucial to confirm the correct placement during forced inspiration and position it 2 cm below the intended site, as the catheter may ascend by 2-4 cm when the patient stands or sits.¹¹⁴

Left-sided catheters tend to retract more. In a retrospective study of 532 internal jugular HD catheters, left-sided catheters terminating initially in the superior vena cava or peri-cavoatrial junction experienced significantly more episodes of dysfunction or infection, compared with those terminating in the mid-to-deep right atrium (0.84 versus 0.35). However, no significant difference was found for right-sided catheters based on tip position.⁹⁶ According to a systematic review by Pittiruti M et al., cardiac tamponade due to vessel or cardiac perforation by a catheter tip placed in the RA is a rare complication.¹¹⁵ Also, the risk of arrhythmias secondary to catheter placement within the RA is not very high.¹⁰⁴ Therefore, the optimal position for the tip of tunneled jugular CVCs is within the mid-right atrium with the patient in a supine position during the procedure.³

In a femoral TCC, the tip position at the junction of IVC and the right atrium was considered ideal. However, this position may increase flow resistance. Therefore, placing the catheter tip within the IVC is generally sufficient to achieve adequate flow.^116,117

Rationale

Typically, catheter dysfunction is clinically suspected or confirmed through basic imaging studies. Common indicators include the inability to aspirate blood from the lumen(s), insufficient blood flow, and/or elevated resistance pressures during HD.¹¹⁸ Interpreting studies that use blood flow as a metric for catheter dysfunction poses challenges, particularly without considering factors like blood pump settings, averaging versus episodic flow measures, recirculation rates, and variations in dialysis techniques such as long daily sessions or slow, low-efficiency dialysis, which operate at lower BFRs.^119,120 Defining dysfunctional catheters solely based on blood flows of <300 mL/min in such cases could lead to unnecessary interventions in most patients.¹²¹ Conversely, delaying intervention until blood flow drops below 300 mL/min may result in avoidable loss of the catheter or access site.¹²²

The previous definitions were focused on intermittent HD, with a standard thrice weekly 4-hour prescription. Changes in definition utilizing both dialysis interruption and blood flow are being considered with the caveat of not mentioning proper cut-offs because of the lack of high-quality evidence to support the same. Therefore, for the present time, the KDOQI definition remains undisputed.

Rationale

The use of UFH as a central venous lock solution is widely adopted due to its cost-effectiveness and practical applicability. However, consensus on the optimal UFH concentration in lock solutions remains elusive according to KDOQI guidelines.³ In an RCT comparing low-dose (1000 U/mL) and high-dose (5000 U/mL) heparin for maintaining tunnel catheter patency, no significant differences were observed in blood flow, venous pressure, arterial pressure, or dialysis adequacy, and there were no serious infection or bleeding events.¹²³ Similarly, another prospective trial comparing higher dose (5000 U/mL) and lower dose (1000 U/mL) heparin locks found no disparities in cumulative catheter survival, infection rates, or patency, with significant cost savings associated with the lower concentration despite higher use of rtPA and no major bleeding incidents in either group.¹²⁴

Contradictory results, however, have been noted in some studies. Yevzlin et al.¹²⁵ reported that concentrated heparin (5000 U/mL) was linked to increased major bleeding complications following tunnel catheter placement compared to low-dose heparin (1000 U/mL) or citrate lock solutions (p = 0.02). A meta-analysis indicated that low-concentration heparin locks (< 5000 U/mL) significantly reduced bleeding events and CRI compared to high-concentration heparin locks, although no significant differences were observed in catheter survival or dysfunction.¹²⁶ Additionally, Holley et al.¹²⁷ and Thomas et al.¹²⁸ observed higher utilization of rt-PA in the low-dose heparin (1000 U/mL) group compared to the high-dose heparin (10000 U/mL) group, with no significant association with catheter dysfunction. Despite the increased rt-PA use, the overall medical costs were significantly reduced with 1000 U/mL heparin locks. Secondary outcomes, such as severe bleeding complications or hospitalizations, did not differ between the groups.^127,128

Furthermore, studies have highlighted the risk of systemic anticoagulation immediately after infusion of 5000 U/mL heparin lock, lasting up to 1-2 hours post-dialysis, posing a bleeding risk.^129,130 In an RCT, significantly elevated APTT (activated partial thromboplastin clotting time) levels were observed 10 minutes after heparin locking in both low-dose (1000 U/mL) and high-dose (5000 U/mL) groups, with a higher incidence of massive bleeding. Decreased hematocrit values were noted in the 5000 U/mL group.¹³¹

Regarding alternative approaches, Yahav et al.,¹³² in a systematic review of seven trials (818 patients; 75185 catheter days), found that citrate lock solutions (with or without antibiotics) reduced infection rates by 64% and catheter removal rates by 44%, without affecting catheter thrombosis. Although Ash et al.¹³³ demonstrated no adverse reactions with catheter sealing using 2 mL of 23% citrate, Power et al.¹³⁴ reported that about 10% of patients experienced a ‘metallic’ taste or temporary tingling in their fingers shortly after injection of ∼6 mL of 46.7% citrate into the central vein (approximately 10 mmoL/L). Overall, evidence supporting high-concentration citrate alone for maintaining catheter patency and preventing CRBSI remains inconclusive.

Rationale

Poor CVC tip positioning occurs when it is placed in the superior vena cava or when the arterial lumen is not placed in the right atrium. This situation is more common in obese patients where positional changes from lying down to standing can shift the tip from the atrium to the vena cava.^114,135,136 This misplacement is also more frequent when the left IJV is used as the point of entry.

The movement from RA to the cavo-atrial junction or superior vena cava is more frequent in CVC located in the left central veins. Some authors have suggested causes inherent to the mediastinal anatomy (elongation of the venous trunks).¹³⁷

Kinking can occur during tunneling of the catheter. If there is inadequate flow or resistance during syringe aspiration post-insertion, intervention may involve introducing a metal guide and replacing the CVC.¹³⁸ According to Spanish guidelines, late catheter dysfunction arises from either catheter thrombosis or the formation of a fibrin sheath^13, which are distinguishable through contrast studies.

Treatment options supported by literature include:

• Vigorous flushing with saline solution: This should be performed using a 10 mL syringe under aseptic conditions to prevent infections¹³⁹. If persistent flow deficits persist after three attempts, fibrinolytic therapy may be initiated.¹³⁸

• Trans-catheter mechanical therapy: This involves extracting thrombi using a guide, Fogarty catheter, or ureteral biopsy brush inserted through the lumen. While it does not cause systemic effects, its efficacy is limited in cases where thrombosis is secondary to a fibrin sheath.¹³⁸

• r-TPA: Multiple studies have shown promising results following the administration of rt-PA as a lock solution. The large multicenter trial pre-CLOT demonstrated reductions in catheter dysfunction and CRBSI rates when rt-PA was used as a lock solution once a month as compared to heparin lock after each dialysis session. Despite early discontinuation and high withdrawal rates this study provided evidence for the use of rt-PA as a catheter lock.^140,141 Yaseen et al.¹⁴² reported improved clearance of catheter dysfunction and prolonged average survival with higher doses of rt-PA, while Savader et al.¹⁴³ and Davies et al.^144,145 found comparable efficacy between push/withdrawal and infusion methods of rt-PA for CVC dysfunction treatment. Concerning CVC without thrombosis, evidence supporting early rt-PA use as a lock solution for prevention remains limited, potentially impacting medical costs.³ Holley et al.¹²⁷ and Thomas et al.¹²⁸ observed higher utilization of rt-PA in the low-dose heparin (1000 U/mL) group compared to the high-dose heparin (10000 U/mL) group, with no significant association with catheter dysfunction. Despite the increased rt-PA use, the overall medical costs were significantly reduced with 1000 U/mL heparin locks. Secondary outcomes, such as severe bleeding complications or hospitalizations, did not differ between the groups.^127,128

• Intraluminal fibrinolytic therapy: No RCT comparing one agent over another has been done thus far; however, several RCTs comparing various doses of the same agent and against placebo have been done. A systematic review by Hilleman et al. evaluated thrombolytic therapy for dysfunctional HD catheters, showing high success rates with reteplase, followed by alteplase and Tenecteplase, with minimal adverse effects¹⁴⁶ with all the agents. According to Semba et al.,¹⁴⁷ a regimen of up to two 2 mg doses of alteplase is safe and effective for restoring flow to occluded central venous access devices. This conclusion is supported by the COOL study, which demonstrated a statistically significant restoration of flow in the alteplase group compared to the placebo group.¹⁴⁸ Administration involves purging lumens with 1 mg/mL alteplase solution, followed by intermittent saline flushes to maintain drug activity at the tip and shorten treatment duration to 30 minutes.¹⁴⁹ Both push and dwell methods are equally effective.¹⁵⁰ High-dose urokinase is much more effective than low-dose urokinase.¹⁵¹

• Systemic fibrinolytic therapy: High-dose urokinase and rtPA systemic infusions have shown similar catheter patency and side effects to intraluminal fibrinolytic therapy.^143,152 However, they need prolonged monitoring and dedicated healthcare personnel and thus are not preferred.

• Systemic anticoagulation: The patency of CVCs in anticoagulated patients is significantly higher compared to non-anticoagulated patients (47.1% vs. 8.1%, p = 0.01). However, due to the risk of bleeding and the need for monitoring, anticoagulation therapy is not routinely recommended for HD patients.^153,154

• Percutaneous fibrin sheath stripping, PTA, and catheter exchange have good patency. However, the patient needs to be subjected to another invasive procedure and recent studies show better resolution with thrombolytics when compared with stripping.^155,156 Another study showed better outcomes with catheter exchange at a lower cost compared to stripping.^157,158 Fibrin sheath PTA followed by catheter exchange showed better catheter patency.¹⁵⁹ Placement of a catheter at a new location to avoid recurrence should be considered as the last resort.^160,161

Rationale

In the retrospective study conducted by Levit et al., patients with AVG who underwent PTA for asymptomatic CVS > 50% experienced more rapid stenosis progression and escalation of lesions compared to those who were not treated.¹⁶²

Similarly, Renaud et al. concluded that withholding treatment in patients with AVF who had asymptomatic or paucisymptomatic CVS resulted in significantly better short- and long-term central vein patency than treating symptomatic cases without negatively affecting the overall dialysis circuit.¹⁶³

In general, PTA ± stenting is associated with poor patency rates. The retrospective study by Bakken et al. showed that primary patency at 30 days was 76% for both angioplasty and angioplasty with stenting, but the 12-month rates dropped to 29% for angioplasty and 21% for stenting.¹⁶⁴ However, another retrospective study in HD patients without CVCs reported a primary patency of 24.5 months in the angioplasty group and 13.4 months in the stent group.¹⁶⁵

Signs and symptoms that may necessitate confirmatory diagnosis and intervention include ipsilateral facial, neck, breast, or extremity swelling (without other cause), repeated thrombosis of upper arm access within 6 months without other causes, pain in the extremity related to venous obstruction, and neurologic symptoms in the absence of other etiologies. Venous pressure is highly variable and depends on many patient and HD factors and their interactions.

The use of a sirolimus-coated DCB for PTA is advised (10.15) as the treatment of choice in cases of recurrent access stenosis due to its efficacy in preventing restenosis. Sirolimus inhibits excessive vascular smooth muscle cell proliferation, reducing the risk of restenosis and maintaining patency. This approach is recommended before considering stenting, particularly when acute elastic recoil > 50%, or stenosis recurs within three months, ensuring optimal VA management in HD patients.¹⁶⁶

Therefore, intervention should not be based solely on venous pressure, but also on other signs and symptoms. Thus, it is prudent to limit stenting to lesions with acute elastic recoil of >50% or stenosis recurrence within three months.^3,164,165

Rationale

A properly functioning VA is essential for performing an effective HD. The three main types of VA available, in order of preference, are AVF, AVG made of biological or prosthetic materials, and TCC or non-TCC inserted into a central vein.^27,167-171 Many studies have demonstrated that AVFs are superior to other types of HDs.^{167,168,171-173} Prioritizing AVF over AVG is a basic recommendation in various international guidelines and among specialists.^{4,27,29,168,174,175} A matured AVF is associated with higher long-term patency, access survival, low rates of complication during the access life, lower rates of access-related sepsis, and lower overall morbidity and mortality as compared to AVG and catheters.^{167,171-173,175}

It has been demonstrated that primary patency rates for AVF at 6 and 18 months are 72% and 51%, respectively, while the secondary patency rates are 86% and 77%, respectively. In contrast, AVG has primary patency rates of 58% at 6 months and 33% at 18 months, with secondary patency rates of 76% and 55%, respectively.¹⁷⁵ The primary disadvantage of AVF over AVG is the high risk of primary failure due to the high rate of immediate thrombosis (5-30% for radiocephalic AVF) and maturation failure (28-53%). In comparison, the primary failure rates for AVG are significantly lower, at 0-13% in the forearm and 0-3% in the arm.¹⁷¹

An optimum VA should allow good-quality dialysis with a lower rate of complications for patients on maintenance haemodialysis (MHD). AVF should be the primary option for VA because it possesses the above-described features.^27,169,170

Rationale

The guideline recommends prioritizing AVFs as the preferred VA option in children whenever possible. This is based on the evidence that AVFs are generally more durable, have lower maturation rates, and are associated with fewer complications.

For children weighing > 20 kg who are expected to wait >1 year for a kidney transplant, using an AVF as the preferred VA is considered reasonable due to its long-term advantages. AVFs typically offer better durability, lower infection rates, and improved patency compared to other access options, making them suitable for patients with extended waiting periods.

For children scheduled for MHD, initiating treatment with a functioning AVF is advisable when clinically appropriate. AVFs generally provide better long-term outcomes and fewer complications compared to other access types, such as CVCs or AVG, ensuring more effective and stable dialysis management.

There is insufficient evidence to make specific recommendations regarding the use of AVGs in children. However, the decision between AVF and AVG should be made on a case-by-case basis, considering factors such as the child's age, weight, vascular anatomy, and overall health. In some cases, an AVG may be the most appropriate option, especially if an AVF is not feasible or takes time to mature. The need for further research is emphasized to establish clear guidelines and recommendations for AVG use in the pediatric population, as AVGs are less commonly utilized, and their efficacy and safety in children remain less well-defined.

Rationale

In the absence of any randomized studies to compare locations for the creation and placement of AVF, but as a good clinical practice, the distal-proximal approach is applied to increase the number of sites for future attempts to place VA.

Although several options are available for AVFs in the arm, the radiocephalic AVF at the wrist, initially described by Brescia-Cimino in 1966, remains the preferred choice for HD.^176,177 This type of AVF is favored due to its low complication rate, preservation of proximal venous capital, and excellent patency rate. However, its main limitation lies in the relatively high immediate failure rate, ranging from 10-50%. Risk factors for poorer outcomes include elderly age, female sex, and diabetes.^176,178

Other potential locations for forearm AVF include:

1. Anatomical Snuffbox AVF: This uses the posterior branch of the radial artery between the tendons of extensor pollicis brevis and extensor pollicis longus, anastomosed with the cephalic vein.¹⁷⁹

2. Radiocephalic AVF in the forearm.¹⁸⁰

3. Radiobasilic Transposition AVF: When the cephalic vein in the forearm is unsuitable, the basilic vein is transposed from the wrist proximally towards the antecubital fossa and tunneled subcutaneously to create an anastomosis.¹⁸¹

4. Ulnarbasilic AVF.¹⁸²

When forearm AVF is not feasible, the antecubital fossa is considered the next option. The larger vessels at this site provide higher flow rates with lower rates of primary or maturation failure. The main drawback is the availability of a shorter needling segment, the risk of steal phenomenon, and limb edema. The brachiocephalic AVF is preferred for this location.¹⁸³

Other options include the proximal radial artery and the cephalic vein,¹⁸⁴ the brachial artery, and the perforating vein in the antecubital fossa (brachioperforating AVF), also known as the Gracz fistula.¹⁸⁵ For patients who cannot have a radiocephalic or brachiocephalic AVF, a brachiobasilic AVF with venous superficialization or transposition is an option.¹⁸⁶

When superficial veins are unavailable, an AVF between the brachial artery and the brachial vein can be considered.^187,188 However, as the vein lies in a deep plane, a second surgery with venous superficialization or transposition is needed.

After the creation of an AVF, many will fail to mature or, if functional, will require intervention within a year due to AVF stenosis. There is a 20–50% risk of maturation failure, resulting in the AVF being unusable, and up to 45–67% of AVFs may develop stenosis, necessitating intervention within a year. During periods of the AVF is not functioning properly, patients might need a CVC as an alternative VA, which increases the risk of infection, hospitalizations, and mortality. Factors contributing to poor AVF maturation and patency include advanced age, female sex, the anatomical location of the AVF (especially radio-cephalic), small vein diameter, comorbidities, surgeon experience, and potential arterial stiffness.

FIR therapy is a novel treatment recommended by the European Renal Best Practice to enhance AVF maturation and patency.^189-196 FIR involves applying electromagnetic radiation (heat) directly to the skin above the AVF. Studies in animal models have demonstrated that FIR induces vasodilation and angiogenesis. Research on FIR’s impact on AVF maturation and survival includes several studies. Lin et al. observed a significant improvement in maturation rates (90% vs. 76% at 3 months) and a lower incidence of AVF malfunction over 12 months with FIR treatment (13% vs. 30%).¹⁹³ Lai et al. reported improved patency rates for AVGs (16% vs. 2%) but not for AVFs (25% vs. 18%) in patients with prior interventions.¹⁹¹ Choi et al. investigated FIR’s effects on cannulation pain and access flow but found no significant difference in AVF survival compared with a control group over 12 months, though the study was not specifically designed to address survival outcomes.¹⁹⁶ Nonetheless, FIR significantly reduced cannulation pain. Overall, FIR shows promise as a treatment for improving AVF maturation and potentially enhancing AVF survival.

Rationale

The use of AVG as a VA is a viable and suitable option, particularly when native AVF is not possible. When compared to native AVF, it has a lower failure rate, a shorter maturation period, is easier for the needle, and is technically less complex to perform.^197,198 An AVG can potentially be used to facilitate a secondary native VA by dilating dilate previously unsuitable veins in the arms to create an AVF. However, AVGs are more expensive and are associated with more morbidity.¹⁹⁸

AVGs have been made from a variety of materials over the years but PTFE, and more recently ePTFE, has been the most used material. This material has been demonstrated to have higher integration rates and a lower risk of infection.¹⁹⁹ A bilayer PTFE prosthesis reinforced with a third elastomer layer can be employed to provide an instantaneous puncture AVG that allows cannulation within 24 hours of insertion.²⁰⁰ A bioengineered prosthesis made of a polyester matrix and sheep collagen has also shown promising results.²⁰¹

An AVG can be implanted in either a straight line or a loop configuration.²⁰² The length of the prosthesis should be 20-40 cm, with a diameter of 6-8 mm.²⁰³ The diameter of the identified arteries or veins for the anastomosis should not be < 4 mm, and the anastomosis should be end-to-side.¹⁹⁸ There is no strong evidence supporting a preferred location for AVG. However, traditionally, to preserve a maximal number of sites for the future, arterial anastomosis is conducted as distally as possible, with preference given to the forearm location before resorting to the upper arm. The order of preference for the arteries is the brachial artery in the antecubital fossa, followed by the brachial artery in the arm, the brachial artery adjacent to the axilla, and the axillary artery.²⁰⁴ The venous anastomosis can be done on veins in the antecubital fossa and above the elbow, as well as the cephalic, basilic, axillary, subclavian, and jugular veins.²⁰²

Rationale

VAs are susceptible to secondary infections, which can have localized to systemic involvement. Such infections pose a significant threat to the viability of VA. Notably, AVF surgeries exhibit a notably low rate of perioperative infections, whereas AVG procedures carry a higher incidence and severity of infections.¹⁹⁸ Staphylococcus aureus stands as the most common microorganism implicated in VA infections. Therefore, a single dose of vancomycin is widely accepted as the prophylactic antibiotic of choice.²⁰⁵

Rationale

There is a high incidence of AVF/AVG failure during the early postoperative period, with thrombosis being the most common cause of these failures. AVF failure can occur either early or late. The incidence of early AVF failure is significantly high (9% to 52%).^206,207 Late AVF failure is typically preceded by stenosis due to various factors, eventually leading to thrombosis.²⁰⁸ The use of salicylates has been associated with a reduction in early AVF failure.²⁰⁹ Clinical trials have shown that clopidogrel is more effective than a placebo in reducing early AVF thrombosis.⁵¹ Additionally, a meta-analysis indicated that various antiplatelet drugs help reduce thrombosis in both AVF and AVG.²¹⁰

However, patients on HD are at an increased risk of bleeding due to factors such as platelet dysfunction, anemia, and the use of heparin during dialysis. Consequently, the use of antithrombotic agents can be associated with an increased risk of bleeding.

Rationale

The appropriate timing for cannulating an AVF or AVG is a controversial issue, as premature cannulation can lead to complications and reduce long-term patency. The maturation period for a VA refers to the duration from the creation of the AVF until the first successful cannulation. Excessive early use may result in patency-associated complications.²¹¹ The DOPPS study showed that AVF use within 2-4 weeks of surgery can be considered with careful clinical evaluation.²¹² For AVGs constructed using PTFE, there is an increased bleeding risk if cannulated within 2 weeks; however, cannulation can be considered between 2-4 weeks if there are no signs of local inflammation and the graft is easily palpable.

Rationale

For a new AVF, using a 17 G needle with a blood flow of up to 250 mL/minute helps minimize trauma and allows for proper maturation of the AVF. Transitioning to a 16 G needle after 2 weeks, when the blood flow exceeds 300 mL/minute, supports increased flow rates and enhances dialysis efficiency while still accommodating the AVF’s development and reducing the risk of complications.²¹³

The rope ladder or rotating needling technique using sharp needles is the preferred method for cannulating AVF and AVG. Although the buttonhole needle technique with blunt needles has been associated with less cannulation pain in smaller studies, results from RCTs are inconsistent.²¹⁴ Furthermore, the buttonhole technique appears to carry a higher risk of both local and systemic infections compared to the rope ladder technique.²¹⁵ However, the buttonhole technique offers a particular advantage for patients with limited access to cannulation sites or fistulas that are difficult to cannulate.²¹⁶

Rationale

AVFs and AVGs are critical for effective HD,²¹⁷ but they are prone to complications like significant stenosis, thrombosis, high flow access, aneurysms, pseudoaneurysms, and steal syndrome. Early identification of flow abnormalities is critical for preventing these complications and maintaining VA patency, ensuring uninterrupted dialysis. Knowledgeable health practitioners must regularly examine AVFs and AVGs for flow dysfunction to detect it early.^218-222

The recommended surveillance interval differs between AVFs and AVGs to account for their unique characteristics. AVFs are generally more durable and less prone to infection or thrombosis, justifying a three-month surveillance interval. In contrast, AVGs are more susceptible to complications such as infection, stenosis, and thrombosis, requiring closer weekly monitoring.^5,45,223

Physical examination remains the primary method of surveillance due to its simplicity, accessibility, and ability to identify clinical signs such as abnormal pulse, bruit, or swelling.^176,224,225 The KDOQI guidelines also emphasize the importance of regular physical examinations to detect access dysfunction early.³ However, complementing physical assessments with flow measurements using devices like Transonic provides an objective evaluation of blood flow, enhancing the sensitivity of surveillance programs.^16,226-229 Progressive reductions in flow rates signal underlying issues like stenosis or early thrombosis, which if left untreated, may compromise access patency or dialysis adequacy.^61,225,230

While individual factors such as the patient’s health and resource availability can influence surveillance frequency, adhering to these recommended intervals ensures timely detection of access dysfunction.

Rationale

Once flow dysfunction is identified through surveillance or clinical examination, prompt intervention is critical for preserving VA patency and ensuring effective HD. Given the limited sites available for VA in patients undergoing long-term HD, preventing access failure is crucial.

Early intervention of stenosis or thrombosis helps in maintaining access patency, minimizes hospitalizations, and extends the VA lifespan.^3,45,107,231

Aneurysms and pseudoaneurysms in AVFs/AVGs can pose significant risks, including rupture and compromised skin integrity overlying the fistula. Compromised skin, characterized by being paper-thin, stretched, shiny, or difficult to pinch above the aneurysm, significantly raises the risk of infection and rupture increases, necessitating prompt intervention.^231,232 Limited puncture sites can also impair effective dialysis, highlighting the need for early intervention to preserve the access site. Evidence from various studies supports the need for surgical repair or endovascular treatment to manage these complications and ensure patient safety.^231,233-237

Steal syndrome, or VA-induced distal ischemia, occurs when blood flow is diverted from the distal limb, leading to ischemic symptoms. Early identification and intervention are crucial to prevent tissue ischemia, necrosis, and limb loss. Kidney guidelines recommend banding, revision, or distal revascularization to mitigate the effects of steal syndrome and restore adequate blood flow to the affected limb.^{3,4,5,29,238,239}

High-flow access, while seemingly advantageous, can also pose risks such as heart failure or vascular steal syndrome, requiring appropriate flow-reducing interventions. Proactive management of AV access with high flows is essential to prevent complications such as high-output cardiac failure.^231,240

Rationale

When clinical monitoring raises suspicion of significant AV access lesions, timely imaging studies are recommended for confirmatory evaluation. Clinically significant lesions contribute to clinical signs and symptoms without other causes. Imaging studies should be conducted promptly, ideally within two weeks, as suggested by KDOQI guidelines, to confirm the diagnosis and plan appropriate interventions.³

The DUPLEX Doppler method is a non-invasive technique, recommended as the primary imaging study technique. It accurately defines the type, extent, and impact of lesions, and provides detailed information on blood flow and vessel structure, making it essential for diagnosing and managing AV access complications.^28,241,242 The ESVS guidelines also endorse using DUPLEX Doppler for VA evaluation.⁴

In cases where DUPLEX Doppler is not feasible or inadequate, or if the lesion is more central, contrast-based imaging studies should be used. Using the smallest volume of iodinated or non-iodinated contrast agents, such as CO₂ gas, minimizes the risk to patients with CKD.^37,243 Operators should be knowledgeable about the uses and contraindications of these contrast agents to ensure patient safety.^244-247 The American Society of Nephrology highlights the importance of minimizing contrast exposure to protect residual kidney function in patients with CKD.²⁴⁵

These recommendations underscore the importance of regular monitoring, appropriate use of imaging, and proactive management in maintaining the function and longevity of AVF and AVG. Timely interventions based on these guidelines can prevent serious complications and improve outcomes for patients on HD.

Rationale

Pre-emptive interventions for AVFs and AVGs with stenosis not accompanied by clinical symptoms are NOT recommended for several reasons rooted in clinical evidence and guidelines.

• Lack of Clinical Benefit: According to the NKF-KDOQI guidelines, interventions should be reserved for cases with a clear clinical indication, as the benefits of pre-emptive angioplasty in asymptomatic patients are not well-supported by evidence.^3,248-250

• Risk of Complications: Angioplasty and surgical interventions carry risks, including infection, vessel rupture, and thrombosis. Pre-emptively performing these procedures on asymptomatic patients may expose them to unnecessary risks without clear evidence of benefit.

• Resource Utilization: Routine pre-emptive interventions can lead to the overuse of healthcare resources.²⁵¹

Pre-emptive interventions such as angioplasty and flow reduction are proactive strategies supported by clinical experience and expert consensus to enhance the long-term success of AV access management, reduce complications, and ensure the continuity of dialysis treatment.

Pre-emptive angioplasty is advised for patients with persistent clinical indicators and underlying AVA stenosis for the following reasons:

• Prevention of Thrombosis: Persistent clinical indicators such as decreased flow rates, prolonged bleeding post-dialysis, signs and symptoms of high recirculation, or recurrent difficulty in cannulation often suggest significant stenosis, which is a precursor to thrombosis. Early intervention can prevent the progression of thrombosis, thus maintaining access patency. Studies have demonstrated that angioplasty in symptomatic patients can reduce the incidence of thrombosis and access failure.^{3,224,249,250}

• Improved Access Patency: Timely angioplasty in patients with clinical symptoms of stenosis has improved the long-term patency of AVFs and AVGs. The KDOQI guidelines support interventions in the presence of clinical indicators to prevent deterioration of the access site.³

• Quality of Life: Managing stenosis before it leads to thrombosis or significant access dysfunction can improve the quality of life for HD patients. Reducing the frequency of access-related complications can decrease hospital visits and interventions, improving overall patient experience.^{3,224,249,250}

Alternatively, pre-emptive flow reduction is advised in patients with symptomatic high flow to lower blood flow to a physiologically acceptable range, preserving access and reducing the burden on the cardiovascular system. Timely intervention not only mitigates the risk of high-flow-related complications but also helps prolong the lifespan of the VA by preventing mechanical stress and structural damage and preventing complications such as high-output cardiac failure.^231,240,252

Rationale

An individualized approach for treating failing or thrombosed AVF and AVG is recommended based on the operator’s clinical judgment, expertise, and available resources,^231,248,249 as a standardized treatment approach may not always suit complex cases. Clinical judgment, operator expertise, and available resources play a critical role in tailoring the treatment plan for each patient, considering the variability in VA conditions.

The treatment process typically begins with thorough monitoring and imaging to identify the underlying issue, followed by targeted intervention. The recommendations emphasize that the severity of stenosis, clinical symptoms, and hemodynamic changes should guide treatment decisions. Surgical or endovascular interventions should be pursued only when they provide clear clinical benefit, ensuring that unnecessary interventions are avoided. For cases involving high-flow AVFs, intervention may focus on flow reduction to balance inflow and outflow, optimizing dialysis outcomes.^{176,249,253-256}

Stenosis, the narrowing of a blood vessel, is a common complication in AVFs and grafts AVGs, occurring in up to 50% of cases. It often affects the venous outflow or arterial inflow, impairing blood flow needed for effective dialysis. If untreated, it can lead to access dysfunction, thrombosis, and reduced dialysis adequacy. Intervention is warranted when stenoses exceed 50% of the lumen diameter and are associated with physiological or clinical abnormalities as listed in Table 2.^{3-5,248,249,257} However, in specific cases of pulsatile AVFs with high outflow stenosis but providing adequate dialysis, flow reduction may be more beneficial than addressing the stenosis directly. This approach can help balance inflow and outflow, optimizing AVF performance and ensuring better dialysis outcomes.²⁵⁸

Balloon angioplasty, using high-pressure balloons when necessary, is the recommended treatment to restore patency and improve access performance. Operators are encouraged to use their clinical judgment to determine balloon inflation duration and pressure based on the specific clinical scenario.^259-261

For recurrent access stenosis or re-stenosis, PTA remains the treatment of choice, particularly if stenosis recurs within three months or if acute elastic recoil > 50%.¹⁶⁶ Self-expanding stent grafts (avoiding bare metal stents) are recommended over angioplasty alone for treating graft-vein anastomotic stenosis and in-stent restenosis in AVGs and AVFs. Studies show that stent grafts provide superior six-month post-intervention outcomes, including lower restenosis rates and improved patency, while also reducing the risk of complications during future cannulation.^262-264 However, stent placement should be carefully planned to preserve future VA options, as emphasized by KDOQI guidelines.^3,45,107

In cases of AVF/AVG thrombosis, timely intervention is critical. Pharmaco-mechanical or mechanical thrombolysis are often preferred for their ability to rapidly restore access, though surgical thrombectomy remains a valid option when endovascular methods are not feasible. Prompt and appropriate treatment minimizes complications and helps maintain VA function.^{225,249,265-270}

Although endovascular techniques such as PTA are the preferred first-line treatment, surgical interventions are considered when endovascular treatments fail or in cases where lesions are not suitable for endovascular procedures, or surgical outcomes are expected to provide better long-term durability.^{3,176,256,265}

Post-intervention, the stenosis and clinical parameters used to detect it should return to within acceptable limits, indicating the success of the treatment. Restoring normal function ensures the long-term viability of the VA site and supports the overall effectiveness of dialysis.

Rationale

Effective management of AVA aneurysms and pseudoaneurysms requires regular monitoring to prevent complications and maintain the longevity of HD access. Early detection through physical examination and duplex ultrasound by trained care providers at each dialysis session is crucial, helping to identify these conditions before the occurence of severe complications, such as rupture or infection.^{176,224,232,237}

Asymptomatic aneurysms or pseudoaneurysms do not require treatment unless complications develop, ensuring resources are focused on symptomatic or high-risk cases.²³¹ When clinical signs indicate potential complications, such as skin breakdown or other symptoms, surgical assessment is recommended. In cases of severe issues like erosion or hemorrhage, immediate surgical intervention is essential to prevent life-threatening outcomes and improve prognosis.^3,176

Patient and staff education plays a critical role in preparing for emergencies, especially for aneurysm rupture. Training patients and dialysis personnel in emergency procedures, such as the use of tourniquets, bottle caps, and manual pressure, equips them to respond promptly and effectively in urgent situations. Ruptures can occur unpredictably due to repeated needle punctures or thinning of the vessel wall, making swift intervention essential to prevent catastrophic blood loss and cardiovascular collapse.²¹⁷

Comprehensive imaging of the arterial inflow and venous outflow is necessary to identify stenotic conditions or volume flow issues that could compromise AVA function. Early diagnosis and correction of these problems help maintain access patency and dialysis effectiveness.²⁴²

Surgical management, including open surgery tailored to the expertise of the treating team, is recommended for large, symptomatic, or rapidly expanding aneurysms and pseudoaneurysms. In some cases, staged repairs may be required. Covered stent grafts can serve as alternatives when surgery is contraindicated, unavailable, or when the facility lacks surgical expertise, helping to prevent rupture and ensure access site functionality.^{234,236,237,259,263}

To minimize the risk of exacerbating these conditions, direct cannulation over aneurysms or pseudoaneurysms should be avoided. If alternative sites are unavailable, cannulating the sides or base instead of the top of the aneurysm or pseudoaneurysm reduces the likelihood of rupture and prolongs the usability of the access site.³

In conclusion, these guidelines provide a comprehensive strategy for managing AV access aneurysms and pseudoaneurysms, focusing on regular monitoring, timely surgical intervention, proactive patient education, and the appropriate use of imaging and cannulation techniques. Adhering to these recommendations helps healthcare providers improve outcomes and prolong the functional lifespan of HD access.

Rationale

Implementing proactive strategies to prevent and manage AV access steal syndrome (AVASS) and ischemic complications is essential to minimize morbidity, including pain, tissue loss, and limb-threatening ischemia. AVASS occurs due to reduced blood flow to distal extremities, and preventive measures like preoperative vascular mapping and optimal access site selection are critical in mitigating this risk. Studies emphasize that early identification and intervention significantly improve patient outcomes.^239,271-277

Patients at high risk—such as the elderly, diabetic, or ones with multiple access attempts in the same limb—require close monitoring. Early symptoms, such as reduced skin temperature, may escalate if not managed promptly. Vigilant monitoring helps prevent long-term disability and improves quality of life while avoiding unnecessary interventions. For patients with mild to moderate symptoms, ongoing monitoring with scheduled follow-ups is essential, with measures like hand exercises or blood flow adjustments offering symptomatic relief. Patients exhibiting moderate to severe symptoms should be referred urgently to vascular specialists to correct hemodynamic changes and prevent permanent damage.^239,271-277

Monthly assessments are recommended to detect early signs of AVASS before complications arise. Standardized checklists should document symptoms such as cold extremities, numbness, pain, or muscle weakness. Clear protocols must be in place for escalating care based on symptom severity, ensuring timely access to specialists. Communication between dialysis units and vascular teams is essential for seamless management. Documentation of all assessments, referrals, and outcomes is critical to guide patient care, and staff must be trained regularly to recognize early signs of ischemia. Patient education on self-monitoring further empowers individuals to take an active role in their care.^239,271-277

Ischemic Monomelic Neuropathy (IMN) is a rare complication of AVF creation, typically presenting as acute nerve ischemia without significant muscle involvement. IMN typically presents with sudden-onset limb pain, weakness, sensory deficits, and tingling, often sparing distal muscle atrophy initially. Unlike steal syndrome, peripheral pulses may remain intact. Patients with underlying vascular conditions, such as diabetes or atherosclerosis, are at higher risk. Prompt surgical intervention, including revision or ligation of the AVF, is essential to restore blood flow and prevent permanent nerve damage or functional impairment.^278,279

Rationale

Initially, access to PD began with a surgical trocar, progressed to rubber catheters, soft polyvinyl intraperitoneal tubes, polyethylene and nylon catheters, and lastly, silicone catheters with a polyester cuff introduced by Tenckhoff in 1968.²⁸⁰ The previously available polyurethane catheters possessed the rupture on exposure of polyethylene glycol to topical mupirocin,²⁸¹ whereas silicone was shown to cause less local tissue irritation when compared to alternative catheter materials. Furthermore, silicone is quite resistant to solvents such as ethanol, as demonstrated in HD catheters.²⁸² Antibiotics such as topical gentamicin were also demonstrated to erode silicone catheters rarely.²⁸³

Multiple variations exist in peritoneal catheter design, each claiming superiority over others. These variations typically involve the number of cuffs (single or double), the design of the subcutaneous tunnel (swan neck or Tenckhoff), and the shape of the intra-abdominal portion (straight or coiled). Different combinations of these characteristics, among others, result in a wide range of available configurations for PD catheters.

The use of single vs. double cuff catheters is debatable, and the selection is usually decided by the operator. A single randomized trial comparing single- versus double-cuffed catheters found no significant difference in the risk of peritonitis, exit site or tunnel infection, or catheter removal.²⁸⁴ In contrast, a large comparative study using Canadian registry data demonstrated that the risk of Staphylococcus aureus peritonitis was reduced in patients using double-cuffed catheters.²⁸⁵ However, a systematic review and meta-analysis comparing data from 13 RCTs did not find any influence of the single vs. double-cuffed PD catheter type on complication rates and catheter survival on pooling results.²⁸⁶

Currently, both straight or coiled tip PD catheters with either a straight segment or a preformed arc bend (swan neck) in the inter-cuff section are being used as the standard of care, per convenience and availability. The clinical practice guidelines of the International Society of Peritoneal Dialysis (ISPD), the British Renal Association, and the European Dialysis and Transplant Association do not support the use of any specific catheter.^287-289 While most RCTs conducted to compare the straight versus coiled catheters have found no significant differences between the two catheter designs,^284,290-295 Nielsen et al. reported a better 1-year catheter survival with the coiled-tip in 77% than straight-tip catheter in 36% of patients.²⁹⁶ However, these trials were limited by the size. In another prospective RCT, Xie et al. compared the catheter tip migration of straight and coiled catheters and meta-analyzed their results with other RCTs. They reported a significant association of the coiled design with increased risk of late (>8 weeks) catheter tip migration but not technique failure. The pooled meta-analysis results also suggested that coiled catheters may be more prone to migration and resultant dysfunction.²⁹⁷ Another meta-analysis/systematic review by Hagen et al. also favored straight PD catheters compared to coiled PD catheters concerning technique survival.²⁸⁶ In 2018, another study compared 151 straight vs. 155 coiled catheter groups that demonstrated significantly lower catheter dysfunction in straight-tip catheters (0.7%) as compared to coiled-tip catheters (5.8%) during an average follow-up of 21 months, thus favoring straight catheters over coiled.²⁹⁸

The current evidence suggests that while both straight and coiled-tip PD catheters are widely used based on availability and operator preference, neither design has shown consistent superiority across studies. Catheter selection should be individualized, considering patient-specific factors and clinical circumstances, including the patient's belt line, BMI, skin creases and folds, presence of scars, chronic skin conditions, intestinal stomas, suprapubic catheters, gastrostomy tubes, incontinence, physical limitations, bathing habits, and occupational activities. For patients with a preferred sleeping position, catheter placement may be optimized by positioning it on the contralateral side of the abdomen to enhance patient comfort and tolerance. The optimal catheter choice achieves a balance between the pelvic positioning of the catheter tip, and placement of the exit site in a low-risk zone for infection that is easily visible and accessible for the patient and allows for insertion through the abdominal wall with minimal stress on the tubing.²⁹⁹

Rationale

To date, no single implantation approach has demonstrated the superiority of any PD insertion technique concerning outcomes. According to multiple systematic reviews and meta-analysis,^{286,297,300,301} operator performance aside, all catheter placement techniques are similar in efficiency. Meta-analyses of various prospective and retrospective cohort studies conclude that advanced laparoscopic interventions such as rectus sheath tunneling and adjunctive procedures demonstrate better outcomes than open insertion or basic laparoscopy, when used only to verify the catheter position.³⁰² Advanced laparoscopy has a lower incidence of catheter obstruction, catheter migration, peri cannular leak, and peri cannular and incisional hernias, with better 1-year and 2-year catheter survival.³⁰²

The ISPD guidelines recommended for choosing a PD catheter insertion method has been outlined in Table 3.^288,299

Paediatric Guideline: The recommendation of conducting surgical placement with partial omentectomy in children when immediate use of the catheter is not planned is grounded in several key considerations. First, when a catheter is placed for PD, the anticipated timing of its use is crucial. In cases where immediate catheter use is not intended, performing a partial omentectomy can significantly reduce the risk of complications. The omentum can obstruct catheter flow and increase the likelihood of malfunction, which can compromise the effectiveness of the therapy. Moreover, the presence of the omentum can serve as a reservoir for infections, including peritonitis. Thus, its removal minimizes this risk and contributes to better long-term outcomes. Studies have shown that catheters placed with an accompanying omentectomy tend to exhibit improved function and lower rates of complications over time, especially for patients requiring prolonged catheter use.

Considering the unique anatomical and physiological characteristics of children, this recommendation holds particular relevance. Children’s smaller body sizes and varying tissue responses necessitate tailored surgical approaches. Performing a partial omentectomy proactively can also help prevent the need for reoperations due to complications, which can be especially detrimental in a paediatric population.^{176,224,241,303-307}

Modern surgical techniques, including minimally invasive laparoscopic methods, enable the safe execution of partial omentectomy alongside catheter placement. This advancement reduces postoperative pain, scarring, and recovery time, aligning to provide effective, patient-centered care.³⁰⁸

Rationale

Based on the data from a randomized trial³⁰⁹ and several observational studies,^299,310-312 there was only a minor increased risk of mechanical complications following an urgent start on PD with a break-in period of < 2 weeks. There was no detrimental effect on patient survival, peritonitis-free survival, or PD technique survival.

ISPD guidelines recommend a break-in period of at least 2 weeks before elective start on PD or a modified PD prescription using low-volume exchanges with the patient in the supine position if an urgent start on PD with a break-in period of < 2 weeks is needed.²⁹⁹ Indian data demonstrated that a break-in period of 2.68 ± 2.6 days ultra-short break-in period is safe.³¹³

Rationale

Most doctors have busy practices and limited time to counsel patients regarding VA, including detailed discussions around vein preservation, different VA options, early conversion from a temporary catheter to an AVF, and prevention of CVS and infection. Currently, this job is fragmented between nephrologists, dialysis technicians, nurses, and primary physicians. The education status of each patient varies, with the majority needing more counselling and regular reinforcement of advice. Patients of non-interventional nephrologists may be reluctant to go to another doctor for VA, delaying the procedure. Patients may feel hesitant to clear their doubts about VA from doctors, and sometimes other CKD problems take precedence. Also, misinformation regarding AVF, fear of painful pricks, and concern for higher chances of primary failure associated with VA deter patients further.^314,315

The VAC can help with detailed counseling and follow-up, implementation of the fistula first strategy, coordination with surgeons, scheduling follow-up visits to monitor AVF maturation, and timely initiation of HD via AVF. According to ESVS guidelines, the VAC can increase the strength of the program by increasing AVF fistula rates, earlier detection of failing AVF, timely intervention to salvage AVF, and reducing catheter infection and dysfunction.^4,314,315 A retrospective review of VA data reports at a medical center in Louisville, Kentucky, USA, demonstrated that after the introduction of a comprehensive access program by a VAC, the prevalence of AVF increased from 50% to 65%. Concurrently, there was a reduction in the number of grafts used, and the proportion of dialysis catheters in use for > 90 days was halved.³¹⁶ In another prospective study, it was noted that the implementation of a multifaceted intervention that included the employment of VAC increased the proportion of patients starting HD therapy with an AVF from 56% to 75%, and the total number of catheter days was reduced to half.³¹⁷

Similarly, in the Netherlands, an access Quality Improvement Plan implemented by VACs resulted in the implantation of more autogenous AVFs, an increase in the frequency of PTAs, and surgical interventions. The strategy was established in 24 centers to reduce VA-related problems through early management of faulty accesses.³¹⁸

A retrospective study was undertaken at an Indian medical institute to analyze the influence of the employment of a trained VAC for fistula monitoring on the progress of the VA program. It indicated that appointing a skilled VAC boosted the number of VA procedures, improved follow-up care, and resulted in early detection and correction for access malfunction while reducing surgeon burden. The overall number of AVFs increased from 511 to 713 (39.3%). The number of follow-up Doppler tests increased from 761 to 1296 (70%), showing enhanced follow-up, and the number of salvage surgeries increased from 44 to 161 (272%), indicating earlier discovery of fistula dysfunction. VAC regularly informed patients and dialysis workers about bedside diagnostics and early referrals for access malfunction. Regular record maintenance and review by VAC ensured that the causes of AVF failures were addressed on time, resulting in satisfactory patency rates.³¹⁹

Rationale

VACs must have adequate hands-on experience with HD patients and be knowledgeable about their issues. The VAC should be chosen based on their experience, knowledge, and organizational, and communication skills with doctors, personnel, and patients. They must be well-versed in dialysis, vascular anatomy and physiology, infection control methods, and VA creation procedures and surgeries. It is proposed that an additional understanding of the vascular Doppler be acquired to assess AV dysfunction.^314,315

VAC’s scope of work may include:^314,315

• Initial assessment for the feasibility of establishing VA, detailed history-taking, and risk assessment for various VA options.

• Providing patient counseling and follow-up regularly.

• Coordinating with departments for radiological assessment of veins and arteries, surgery scheduling, and follow-up care.

• Educate the patient regarding fistula care and assessment of thrill.

• Timely initiation of HD via AVF and evaluation of all difficult cannulations.

• Fistula assessment to detect early failure and to schedule corrective procedures.

• Regular follow-up after initiation of HD to detect complications and schedule corrective procedures.

• Education of patients regarding CVC care, prevention of infection, and identification of signs of complications like CVS.

• Regular education of dialysis staff about VA and prevention of infection.

• Record keeping and audit.

• Developing and implementing protocols for staff support and patient education.

Currently, since there are no formal training courses for VACs and their role is ever-evolving, it is recommended that they keep up to date with the latest VA guidelines and procedures. Nursing coordinator curricula for European and Canadian societies are regularly updated and can be used as references.^320-322

Rationale

In Tables 4 and 5 (guideline 7.4), we have collated key clinical signs and symptoms that will facilitate the dialysis nurse/technicians for prompt identification of an early VA (CVC and AVF) flow dysfunction and timely referral to an interventional nephrologist or surgeon for resolution. These include:

• Use of temporary catheter for > 2 weeks: Although the primary choice of VA in HD patients is generally an AVF and TCC in cases where AVF is not possible, sometimes patients require a temporary VA because of acute kidney failure, or due to slow maturation or failure of their permanent VA. In these situations, n-TCCs are used. These can be inserted with relative ease by a bedside procedure under local anesthesia without forming a subcutaneous tunnel and are usually intended for a relatively short time. However, it has been reported that n-TCCs have a higher risk of infection and complications than TCCs, and therefore, their use should be limited.⁴⁶ According to the KDOQI guidelines, the experts consider it reasonable to limit the use of temporary n-TCCs to a maximum of 2 weeks due to the increased risk of infection, and this should be considered only in patients in need of emergent access.³

• Inadequate BFR and inadequate dialysis: The KDOQI guideline defined CVC dysfunction as “failure to attain and maintain an extracorporeal blood flow sufficient to perform HD without significantly lengthening the treatment time” where sufficient extracorporeal BFR is considered as 300 mL/min.^3,27 However, a study published in 2006 reported that a BFR between 250 to 300 mL/min may deliver adequate dialysis, especially in patients weighing <70 kg.¹²¹ While, for smaller patients, flows of 300 mL/min may be sufficient, larger patients may require prolonged daily dialysis sessions with lower flow rates, such as 270 mL/min. In such cases, other measures of inadequate dialysis such as values of Kt/V or URR could also indicate CVC flow dysfunction. According to the NKF, for the dialysis to be adequate, the Kt/V should be at least 1.2 or if URR is used, it should be 65% or more.¹⁰⁷ The values for BFR and inadequate dialysis are the same for AVF. In addition, for AVF, a decrease in intra-access blood flow, as recorded on Doppler/MR angiography, to <500 mL/min is also a sign of VA flow dysfunction and may indicate the need for an angiography.³²³

• Arterial/venous pressure and higher recirculation: Other clinical signs indicative of failure of a VA include either an increase in venous pressure or a decline in arterial pressure. According to the 2006 KDOQI guideline, a pre-pump arterial pressure of -250 mmHg (corresponding venous pressure of 250 mmHg) must maintain a BFR of 300 mL/min or greater. > 3 incidences of change in arterial or venous pressure than the recommended value warrants a referral to a specialist.²⁷ In addition to elevated arterial and venous pressures, CVC dysfunction can lead to significant recirculation, resulting in poor clearance and lower Kt/V. Such CVCs become nonfunctional without intervention and require premature removal.³²⁴ Similarly, the guidelines dictated that recirculation values exceeding 10% obtained through urea-based measurements warranted further investigation.²⁷

• Physical signs of stenosis: These include swelling of the arm, breast, face, or neck. On physical examination, there may be numerous dilated collaterals in the neck, chest, and arm edema. Symptoms like cold extremities, pain and, sensory loss of hand with AVF, or ulcers on fingers are signs of ischemic VA steal syndrome where occlusion in the AVF results in reduction or reversal of blood flow to the hand. Other physical examinations for examining AVF flow dysfunction include palpation of the entire AVF tract, arm elevation, pulse and thrill abnormalities, and pulse augmentation tests.^{48,49,218,219,325-328}

• Other signs of CVC dysfunction include the use of thrombolytic agents > 3 times, the occurrence of tunnel site infection or recurrent line sepsis, and signs of physical catheter damage.

Rationale

Standardized definitions for CVC-related infections, including exit site infection, tunnel infection, and CRBSI, ensure consistent diagnosis, treatment, and reporting across healthcare institutions. This approach enhances patient outcomes by enabling healthcare providers to apply evidence-based protocols effectively, facilitating early detection and management of infections, and reducing complications such as sepsis and prolonged hospitalization. The Infectious Diseases Society of America (IDSA) highlights that using uniform definitions lowers infection rates and improves clinical outcomes.^329-331 Additionally, standardized definitions support research and quality improvement by allowing for the collection of comparable data across institutions, which is essential for epidemiological studies and the development of best practices.³³² This consistency also aids in developing and implementing national and international guidelines, as emphasized by the WHO and IDSA.^329-331,333 Adopting these standardized definitions is essential for improving the consistency of care, supporting effective clinical guidelines, and ultimately enhancing patient safety and outcomes.

Rationale

The strict implementation of a universal infection prevention protocol, including hand washing, mask usage (for both patients and operators), hub cleaning techniques, and glove use, is essential in healthcare settings, particularly during procedures involving VA like dialysis.^334,335 Infections associated with VA can significantly impact patient morbidity and mortality, and increase healthcare costs.

Hand hygiene is one of the most effective measures for preventing healthcare-associated infections (HAIs). Research demonstrates that proper hand washing can substantially reduce the transmission of pathogens, aligning with WHO guidelines that emphasize hand hygiene as a key practice to interrupt the chain of infection.³³⁶ This practice should occur before patient contact, after handling bodily fluids, and upon removing gloves, ensuring adherence to proper techniques to maximize efficacy.^334,335

The use of masks serves as a barrier against respiratory droplets that may carry pathogens, protecting both patients and healthcare providers. This is particularly critical in cases where patients have compromised immune systems. Evidence indicates that routine mask usage in healthcare settings significantly reduces the incidence of respiratory infections.^334,335

Employing proper hub cleaning techniques prior to accessing intravenous lines or VA sites is crucial for minimizing the risk of CRBSIs. Utilizing appropriate antiseptics, such as chlorhexidine, has been shown to lower infection rates. Standardizing hub cleaning protocols ensures consistency among healthcare providers, reducing variability that can lead to lapses in infection control.³³⁵

Finally, wearing gloves offers a physical barrier against contamination, safeguarding both patients and healthcare workers. Gloves should be utilized during all procedures involving contact with bodily fluids or open wounds to prevent pathogen transmission. Emphasizing the use of single-use gloves mitigates the risk of cross-contamination, while proper disposal practices further enhance safety in clinical settings.^334,335

Including an infection surveillance team within an infection control program to monitor, track, help prevent, and evaluate outcomes of VA infections, particularly CVC-related infections, is a crucial strategy for improving patient safety and healthcare quality. Surveillance teams play a pivotal role in systematically collecting and analyzing infection data, allowing for the identification of infection trends and the timely implementation of targeted interventions. Studies have shown that active surveillance and feedback significantly reduce the incidence of HAIs.³³⁷ An electronic database for tracking infections enhances data accuracy and accessibility, enabling real-time monitoring and rapid response to emerging infection threats.

The CDC) and the IDSA emphasize the importance of robust infection surveillance systems in reducing the rates of CVC-related infections. For instance, the CDC's National Healthcare Safety Network (NHSN) provides a standardized platform for tracking HAIs, including CVC-related bloodstream infections, facilitating national benchmarking and quality improvement initiatives.³³² The presence of a dedicated surveillance team ensures adherence to infection control protocols, promotes the adoption of best practices, and fosters a culture of continuous quality improvement.

Furthermore, infection surveillance teams can provide valuable insights for training and educating healthcare staff on infection prevention measures, thereby enhancing compliance and reducing infection rates. The WHO also supports the establishment of infection prevention and control programs, including surveillance activities, as essential components of patient safety efforts.³³³ By systematically tracking and analyzing infection data, surveillance teams can identify risk factors, assess the effectiveness of interventions, and guide policy development to mitigate infection risks.

Overall, incorporating an infection surveillance team within an infection control program is a reasonable and evidence-based recommendation that aligns with international guidelines and best practices, significantly contributing to the prevention and management of VA infections, particularly those related to CVCs.

Rationale

Advising the inclusion of obtaining a basic medical history focused on signs and symptoms of catheter complications, coupled with a physical examination of the exit site, tunnel, and surrounding area at each dressing change or dialysis session, is a prudent measure of monitoring and surveillance programs. This practice ensures early detection and timely intervention for CRIs, which are significant complications in patients with CVCs.

Regular and systematic evaluation of the catheter site can help identify early signs of infection, such as redness, swelling, tenderness, or discharge, which are critical indicators of exit site infections, tunnel infections, or CRBSIs. According to the IDSA guidelines, prompt recognition and management of these signs are essential in reducing CRI-associated morbidity and mortality.^329-331 A thorough medical history that includes patient-reported symptoms like fever, chills, or pain can further assist healthcare providers in identifying potential complications before they become severe.

Literature supports the efficacy of routine monitoring in preventing CRIs.^{77,95,122,161,338,339} CDC recommends regular assessments of catheter sites during dressing changes to detect and address infections promptly.³³² Additionally, physical examinations during dressing changes or dialysis sessions provide an opportunity to evaluate the integrity of the catheter and its securement, ensuring that the device functions properly and remains free from mechanical complications. This practice aligns with the CDC's guidelines for the prevention of intravascular CRIs, which emphasize the importance of routine site assessment as a key component of infection control strategies.^77,339

Incorporating these evaluations into routine care protocols enhances patient safety by facilitating early intervention and preventing the escalation of infections, thereby improving overall clinical outcomes. Therefore, it is reasonable to advise that obtaining a focused medical history and conducting a physical examination at each dressing change or dialysis session are integral parts of a comprehensive monitoring and surveillance programs for catheter-related complications.

Rationale

The recommendations regarding use of selective prophylactic antibiotic locks in long-term catheters, particularly for patients at high risk of CRBSIs, are grounded in evidence, indicating their potential benefits in preventing such infections. Studies have shown that antibiotic locks with agents such as cefotaxime, gentamicin, or cotrimoxazole can reduce the incidence of CRBSIs in high-risk patients, especially in settings with high infection rates (> 3.5 per 1000 catheter days).^340-345 Additionally, the use of taurolidine and heparin combination lock solutions, as presented in Defend Cath, further enhances infection prevention strategies. Taurolidine has been shown to possess broad-spectrum antimicrobial properties and can disrupt biofilm formation on catheter surfaces, thereby reducing the risk of CRBSIs. Heparin locks provide anticoagulant properties, maintaining catheter patency while minimizing thrombus formation. The combination of these agents can effectively lower infection rates and improve outcomes in patients with long-term catheters.³⁴⁶

Similarly, antimicrobial locks like trisodium citrate and taurolidine locks have been considered because they effectively reduce CRBSIs. Research suggests that these antimicrobial lock solutions can be effective in preventing biofilm formation and catheter colonization by various pathogens, thereby reducing CRBSI risk.^346,347 These interventions are particularly relevant for patients with multiple prior CRBSIs, as they are at an elevated risk of recurrent infections.

However, routine prophylactic use of antibiotics or antimicrobial locks is not recommended. This caution is based on concerns about promoting antimicrobial resistance and potential adverse effects associated with the widespread use of these agents. The IDSA and other guidelines emphasize that the routine use of these prophylactic measures should be avoided to prevent the development of resistant organisms and maintain the efficacy of available antibiotics.^{3,329-331,338,339,348}

Therefore, the selective use of prophylactic antibiotics and antimicrobial locks is justified in specific high-risk scenarios and institutions with elevated CRBSI rates, balancing effective infection prevention with the risks of antibiotic resistance and adverse events.

Rationale

The recommendations for managing CRIs emphasize evidence-based practices that enhance patient outcomes and align with current guidelines. Obtaining appropriate cultures from CVC before initiating empiric antibiotics for suspected CRIs is essential. This approach ensures that therapy is targeted and effective, reducing the risk of resistance and improving patient outcomes. Literature supports this strategy, highlighting that empiric therapy guided by culture results is critical for optimal treatment.³³⁰ Additionally, studies have shown that targeted antimicrobial therapy based on culture results can significantly reduce CRBSIs.³⁴⁹ Alternatively, in centers using single-use dialyzers and tubing, a sample from the dialysis tubing may be used.

Without a common consensus on treatment protocols, the management of CRIs should follow local antibiograms and policies, using empirical antibiotics where appropriate. This recommendation is supported by expert opinion and guidelines, suggesting specific durations for antibiotic therapy based on the type of infection: 4-6 weeks for uncomplicated Staphylococcus aureus, 7-14 days for Gram-negative bacilli or Enterococcus, and a minimum of 14 days for Candida species.³²⁹ This stratification ensures that treatment is appropriate for the pathogen involved, minimizing the risk of prolonged infection and complications.

For interventions targeting the catheter exit site, the use of ointment and dressings is recommended. In contrast, interventions targeting the catheter hub and lumen should include scrubbing the hub and using antimicrobial, antibiotic, or anticoagulant catheter locks alongside decolonization protocols. This comprehensive approach, supported by moderate-quality evidence, aims to reduce the risk of infection by addressing all potential entry points for pathogens.³³⁸ Studies have demonstrated that the use of antimicrobial locks can significantly reduce the incidence of CRBSIs in high-risk patients.^79,340,350

For tunnel infections, obtaining cultures from the tunnel/exit site and blood culture from the catheter is advised, with a typical treatment duration of 10-14 days without concurrent bacteremia. This duration may be adjusted based on the presence of concurrent CVC infection. This recommendation is supported by evidence suggesting that targeted treatment based on culture results improves outcomes and reduces the risk of recurrent infections.^77,339 Moreover, early identification and targeted treatment of tunnel infections have been shown to prevent more severe complications and improve overall catheter survival.³⁵¹

Rationale

The management of CRBSIs necessitates an individualized approach tailored to the patient’s health, dialysis needs, and VA circumstances. Current guidelines and literature underscore the importance of this personalized strategy to ensure optimal outcomes and effective resource utilization. There are four main options for managing CRBSIs, which involve either removing or retaining the CVC, each with specific indications based on clinical scenarios.

When opting to remove the CVC, two primary approaches can be considered. The first option is CVC removal with exchange over a guidewire at the same site, which can be effective in maintaining VA while treating the infection, provided there is no evidence of tunnel or severe systemic infection. The second option involves removing the CVC and replacing it at a new site, potentially after a "CVC-free" duration, in which a temporary CVC may be used for dialysis. Immediate CVC removal followed by delayed placement is indicated in hemodynamically unstable patients, those with persistent fever (48 to 72 hours) despite receiving systemic antibiotics, exhibit persistent bacteremia after 72 hours of antibiotic treatment, develop metastatic complications (such as suppurative thrombophlebitis or endocarditis), infections caused by Staphylococcus aureus, Pseudomonas aeruginosa, fungi, or mycobacteria, or suffer from a tunnel-site infection.^77,330,339 In the case of uncuffed, temporary CVCs, infections due to Gram-negative bacilli, S. aureus, enterococci, fungi, and mycobacteria warrant CVC removal.³⁵¹ At the time of CVC removal, evaluating for the presence of a fibrin sheath (which may harbor an infected biofilm) and performing fibrin sheath disruption is recommended (Guideline Statement 26.3).

If the decision is made to retain the CVC, two options exist: retaining the CVC with the use of an antibiotic CVC lock or without it. Antibiotic locks, combined with systemic antibiotics, may be an alternative strategy to preserve the CVC. While there are no RCTs specifically evaluating the role of antibiotic CVC locks in the treatment of CRBSIs, several observational studies have demonstrated the eradication of bacteremia with antibiotic locks combined with systemic antibiotics, compared to CVC exchange or removal.^330,351 This approach is particularly beneficial in patients with limited VA options, helping to maintain their existing catheters while effectively managing the infection.

The rationale for these individualized management strategies is supported by guidelines and studies emphasizing the complexity and variability of CRBSIs. The IDSA guidelines advocate for personalized treatment plans that consider patient-specific factors, which is crucial for enhancing patient outcomes, minimizing complications, and preserving vital VA.^330,331

Rationale

POCUS is performed at the bedside by the treating clinician to solve clinical problems. It expedites clinical decision-making and patient care.^352,353 However, it is not a substitute for a detailed ultrasound examination by the radiologist/sonographer. POCUS is gaining wide acceptance in dialysis access care like any other medical specialty. The use of POCUS starts with planning the access to maintenance of the access, either PD or HD.

Ideally, all VA procedures should be performed under imaging guidance.^3,353,354 However, this may not be feasible for two reasons. First, there may be a lack of personnel trained in POCUS available around the clock at dialysis facilities. Second, portable ultrasound machines may be unavailable due to legal hindrances, turf wars, and financial constraints.

Given these challenges, it may be necessary to proceed with VA procedures without USG as a routine practice in resource-limited settings. This approach can reduce delays in providing KRT during emergencies. However, there are specific conditions under which performing access procedures under USG is essential.

These conditions can be categorized into several groups. The first group includes patients with a history of prior vascular catheterization, which could have caused stenosis, occlusion, or thrombosis of the vessels. To avoid complications, confirming vessel patency beforehand is crucial to prevent accidental arterial puncture.

The second group consists of patients whose neck or groin anatomy has been altered due to prior surgery or local abnormalities such as scoliosis, kyphosis, goiter, or flexion deformity.

The third group includes patients requiring left IJV cannulation. On the left side, there are significant variations in the anatomical relationship between the IJV and carotid artery.^85,355 In these cases, Performing the procedure under USG reduces the risk of accidental carotid artery puncture and increases the success rate of cannulation.

The use of USG in pediatric care is supported by its ability to enhance procedural success, improve patient safety, reduce discomfort, and provide real-time information. As pediatric patients present unique challenges, incorporating POCUS into clinical practice can significantly improve the quality of care provided to this vulnerable population.

Rationale

See Rationale for Guideline Statement 1.4

Rationale

See Rationale for Guideline Statement 1.5

Rationale

Establishing a uniform definition of stenosis is crucial for consistency in diagnosis and management across healthcare institutions, ensuring reliable comparison of clinical outcomes and standardization of treatment protocols.³⁵⁶ Using Doppler ultrasound to assess the reduction in vascular lumen provides an objective and non-invasive measure, supported by studies highlighting the precision of ultrasonography over angiography in diagnosing access stenosis.^357,358 Adhering to high-risk thrombosis criteria (as listed in Table 6), integrates evidence-based thresholds associated with adverse outcomes, prioritizing interventions for clinically significant stenoses, as emphasized by Tessitore et al. (2004) and Aragoncillo et al. (2016).^219,359 They found that pre-emptive repair of subclinical stenosis can prolong the life of AVF. This approach prevents complications like thrombosis and access failure, enhancing patient safety and AVA longevity. Clear criteria also optimize healthcare resources by focusing interventions on high-risk patients and avoiding unnecessary procedures.

Defining non-significant stenosis as those not meeting high-risk criteria prevents over-treatment, reducing patient exposure to procedural risks and healthcare costs, as highlighted in the meta-analysis by Muchayi et al. (2015)³⁶⁰, which discusses the outcomes of monitoring access flow and preventing unnecessary interventions. It ensures that resources and attention are concentrated on higher-risk patients, improving clinical efficiency and decision-making. Differentiating between significant and non-significant stenosis aids in providing care aligned with best practices and current research, enhancing patient outcomes. By adopting these guidelines, healthcare providers can ensure standardized, evidence-based management of AVF, focused on patient safety and effective resource use. stenosis.

Rationale

The guidelines recommend using USG-guided endovascular treatment as the primary option for managing stenosis in AVF due to its lower complexity and reduced healthcare costs compared to surgical alternatives. This approach is supported by numerous studies, which have demonstrated the effectiveness and cost-efficiency of USG-guided angioplasty in treating AVF stenosis. Surgical treatment should be reserved for non-stenotic cases where endovascular options are not applicable.^361-365

The guidelines also recommend timely elective interventions upon diagnosing significant AVF stenosis to mitigate the high risk of thrombosis.³⁶⁶ Early intervention, preferably through USG-guided PTA or surgery, prevents complications and prolongs the lifespan of the AVF. Studies have reported improved outcomes and reduced thrombosis rates with early endovascular treatment.^{253,254,367-369}

Furthermore, prioritizing the restoration of patency in potentially recoverable thrombosed AVFs within the first 48 hours is crucial. Early intervention can prevent the need for CVC placement associated with higher infection rates and other complications.^253,360 Overall, these guidelines aim to optimize the management of AVF stenosis and thrombosis, improve patient care, and reduce healthcare costs through evidence-based practices.

Rationale

The guidelines suggest treating venous JAS using USG-guided angioplasty or surgery, depending on available resources and expertise. This recommendation is based on evidence indicating that both approaches are effective, with the choice largely influenced by institutional capabilities and clinician proficiency. Studies have shown comparable outcomes for surgical and angioplasty treatments in managing JAS, highlighting the flexibility in choosing the appropriate intervention based on specific circumstances.^{220,365,370-372}

The guidelines recommend USG-guided angioplasty as the initial treatment for non-JAS of native AVF due to its less invasive nature than surgery. This approach minimizes patient recovery time and reduces the risk of complications associated with surgical interventions. Overall, prioritizing USG-guided angioplasty aligns with best practices for enhancing patient outcomes while efficiently utilizing healthcare resources.

Rationale

The recommendation to use high-pressure balloon angioplasty, including ultrahigh-pressure non-compliant balloons, as the primary treatment for significant AVF and AVG stenotic lesions is supported by extensive research demonstrating their efficacy and safety.^260,373-386 High-pressure balloons are designed to resist deformation, allowing for effective dilation of resistant stenotic lesions. Studies have shown that these balloons can achieve superior patency rates compared to standard balloons, particularly in complex and resistant stenotic sites.^373,381,386 In special situations, such as heavily calcified lesions, specialized balloons (like cutting or scoring balloons) may be necessary to achieve optimal results.^{373,379,380-383}

The recommendation for an optimal balloon inflation time during angioplasty, ideally between 90-180 seconds, is based on evidence indicating that prolonged inflation improves primary patency rates. Longer inflation times ensure adequate vessel wall remodeling and reduce the likelihood of elastic recoil.^387,388

Finally, the guideline advising a careful, patient-individualized approach in choosing the type of balloon for angioplasty emphasizes the importance of clinical judgment and expertise. Choosing a balloon should be tailored to the specific characteristics of the stenosis and patient factors, such as lesion location, severity, and vessel anatomy. Research supports this individualized approach, highlighting that operator experience and the nuanced understanding of different balloon technologies can significantly impact the effectiveness of the treatment.^260,385 The proposed guidelines underscore the benefits of a tailored approach, demonstrating improved outcomes when the choice of intervention is guided by the operator's clinical judgment and expertise.

Rationale

The recommendations outlined in guidelines 10.11 through 10.14 focus on optimizing AVF treatment using USG angioplasty, with an emphasis on stent deployment and the management of specific stenosis types, reflecting a strategy aimed at improving AVF longevity and functionality. The suggestion to use stents under USG guidance in selected cases (10.11) with a technical angioplasty failure or frequent stenosis relapse draws on evidence indicating improved patency rates when stents are reserved for these specific scenarios rather than routine use.^368,389-397 However, their avoidance in venous confluence is recommended due to the higher risks of complications or failure in these anatomical regions.

For cephalic vein arch stenosis (10.12), USG-guided angioplasty is recommended as the first line of treatment. This approach aligns with studies demonstrating the efficacy of angioplasty and lower complication rates compared to more invasive procedures. Stent placement or surgical transposition are suggested as secondary alternatives when angioplasty is insufficient, supporting a tiered approach to intervention that maximizes vein preservation.^398-406

In managing non-matured AVFs, guidelines 10.13 and 10.14 advocate for USG-guided angioplasty of proximal venous and arterial stenosis, respectively. This recommendation is based on research showing that early intervention in these stenotic segments can facilitate AVF maturation and prevent the need for more invasive surgical revisions.^407,408 The specific focus on using angioplasty without compromising limb vascularization (10.14) underscores the necessity of preserving overall limb health while addressing AVF issues, reflecting a principle widely accepted in VA management.

Guideline 10.15 suggests using surgical options, such as proximal re-anastomosis, for maturation failures associated with JAS, recommending endovascular treatment when surgical options are limited. Surgical correction of anatomical defects at or near the fistula anastomosis can effectively resolve issues impeding maturation. Endovascular treatments serve as a less invasive and efficient alternative, especially in centers with limited surgical expertise or resources.⁴⁰⁹

The use of a DCB for PTA is advised (10.16) as the treatment of choice in cases of recurrent access stenosis due to its efficacy in preventing restenosis. DCBs deliver localized doses of anti-proliferative drugs directly to the vascular wall during the angioplasty procedure, effectively reducing the risk of neointimal hyperplasia, a leading cause of restenosis.

The effectiveness of DCBs is attributed to their ability to inhibit smooth muscle cell proliferation and migration, which is crucial in maintaining long-term vascular patency. Clinical studies have shown that DCBs significantly decrease the rates of restenosis compared to conventional balloon angioplasty, resulting in improved long-term access success rates. This approach is recommended before considering stenting, particularly when acute elastic recoil exceeds 50% or in patients with recurrent access stenosis (stenosis recurs within three months), where previous interventions may have already failed to maintain adequate VA.¹⁶⁶

Commonly used DCBs based on their drug composition include:

• Paclitaxel-Coated Balloons: Known for their ability to inhibit cell proliferation and inflammation, thus significantly reducing the rate of restenosis.

• Sirolimus-Coated Balloons: These balloons release sirolimus, which is effective in reducing neointimal hyperplasia and preventing restenosis in VA sites.

Together, these guidelines emphasize a precision-based approach to managing AVF complications. They promote less invasive techniques as initial interventions and reserve more complex procedures for cases where simpler methods fail. The strategy aligns with current best practices and supports improved patient outcomes through tailored interventions.

Rationale

Guideline 10.17 recommends performing imaging tests immediately after thrombectomy to identify any underlying stenoses that might require treatment. This practice is supported by research indicating that post-thrombectomy imaging can significantly improve the long-term success of AVF by detecting and allowing for the immediate treatment of residual stenotic lesions that could otherwise lead to re-thrombosis.^5,410 Failure to address underlying stenoses at the time of thrombectomy leads to a significantly higher rate of AVF failure.²²⁴ This recommendation is aligned with the consensus that comprehensive post-procedure imaging not only confirms the removal of thrombus but also ensures that all contributing factors to AVF dysfunction are addressed, thus enhancing overall patency rates.

Guideline 10.18 suggests a clinical check-up at 4-6 weeks post-creation to detect delays or absence of AVF maturation, with elective treatment if necessary. The proposed period is chosen based on evidence that most well-functioning AVFs start to mature within this timeframe. Early detection of maturation failures allows for timely interventions, such as angioplasty, which can salvage the functionality of the AVF.^224,407,410 This guideline underscores the importance of early detection and management of maturation issues, which is crucial for reducing the need for CVCs and associated complications.

Guideline 10.19 suggests early treatment of non-matured native AVFs to promote maturation and prevent thrombosis and subsequent loss. The rationale for this guideline is supported by the recognition that early intervention can resolve issues such as flow-limiting stenosis or inadequate blood flow, which are common causes of non-maturation. Early detection and treatment of anatomical and hemodynamic deficiencies in AVFs can significantly enhance maturation rates and reduce the incidence of thrombosis.^{5,224,366,407}

In contrast, Guideline 10.20 advises against the routine use of percutaneous or surgical techniques to promote AVF maturation. This recommendation stems from evidence suggesting that not all immature AVFs benefit from such interventions and that unnecessary procedures could cause harm or lead to higher healthcare costs.⁵ A conservative approach, focused on monitoring and intervening only when specific issues are identified, yields better overall outcomes for patient safety and fistula longevity.²²⁴

Finally, Guideline 10.21 recommends disconnecting significant accessory veins associated with maturation failure using techniques, such as percutaneous or surgical ligation or USG-guided endovascular embolization with coils. The rationale for this guideline is supported by findings that accessory veins can divert blood flow away from the primary fistula channel, thus hindering maturation.^{224,243,250,400,406,407,411,412} The removal or occlusion of these veins has been shown to redirect flow, enhance shear stress, and promote vein dilation and thickening, which are crucial for successful AVF maturation.

Together, these guidelines provide a comprehensive approach to managing AVFs that fail to mature, aiming to maximize their usability for HD through timely interventions based on the underlying cause of non-maturation.

Rationale

The rationale for the preoperative procedures for kidney biopsy is grounded in evidence-based recommendations aimed at optimizing patient safety and procedural success. Routine care before biopsy involves measuring hemoglobin, platelet count, INR, activated partial thromboplastin time, and good blood pressure control.^413-415 Monitoring of platelet count and INR levels, with thresholds set above 50,000/μL and < 1.5, respectively, is essential to mitigate the risk of bleeding complications during the procedure.^413-415 Continuing aspirin therapy in high-risk patients, supported by studies indicating the increased risk of cardiovascular events associated with aspirin cessation, ensures ongoing cardiovascular protection.^209,416-420 Conversely, discontinuation of aspirin in low-risk patients before biopsy balances bleeding risk with the need for cardiovascular protection.^416,417,421 Bridging anticoagulation is recommended for patients at the highest thromboembolic risk, aligning with guidelines for anticoagulation management in other medical procedures.^422,423 Discontinuation of anticoagulant and antiplatelet medications before biopsy, coupled with delayed restart post-procedure, minimizes bleeding risk while maintaining essential medication efficacy.^413,422,423 Non-urgent biopsies are often postponed until antiplatelet and anticoagulant agents have been discontinued for several days.^413,422 Lastly, the administration of desmopressin acetate before biopsy in uremic patients with CKD stage IIIb and above aims to reduce bleeding complications, supported by its efficacy in other invasive procedures.^413,424

Rationale

The choice of needle diameter in kidney biopsy procedures significantly impacts the quality of tissue samples obtained and subsequent diagnostic accuracy. Previous studies have highlighted the influence of needle diameter on parameters such as glomeruli number, width, and miss rates during biopsy procedures.¹⁷⁶ Radiologists performing kidney biopsies tend to favor smaller diameter needles (18G/20G) compared to nephrologists, who often use larger gauge needles (14G/16G). It has been observed that smaller needles result in a lower number of glomeruli per centimeter of core biopsy and a narrower mean core width, potentially affecting diagnostic yield.⁴²⁵

Moreover, the literature indicates several significant drawbacks associated with the use of smaller gauge needles, such as 18G. Firstly, smaller needles lead to greater fragmentation of the tissue sample, impairing accurate evaluation of the tubulointerstitial compartment, which is crucial for patient prognosis.⁴²⁶ Secondly, studies have reported that up to 50% of glomeruli may be lost or floating in biopsies obtained using 18G needles, further compromising diagnostic reliability.⁴²⁷ Lastly, the smaller volume of tissue obtained with an 18G needle results in fewer total sections available for analysis, as evidenced by the significantly lower mean width of kidney cores obtained with 18G and 20G needles compared to larger gauge needles.^428,429

Taken together, these findings underscore the importance of considering needle diameter carefully in kidney biopsy procedures to optimize diagnostic yield and minimize the risk of sampling-related complications. While smaller gauge needles may offer certain advantages, particularly in terms of patient comfort and procedural ease, their limitations in terms of tissue sample quality and diagnostic reliability must be carefully weighed against these benefits. Therefore, a balanced approach, considering the specific clinical context and the expertise of the performing physician, is essential in needle selection for kidney biopsies.

Rationale

The rationale for recommending image-guided percutaneous kidney biopsies, particularly with real-time USG, is grounded in evidence demonstrating improved safety and efficacy of these procedures. Image guidance enhances the accuracy of needle placement, leading to better tissue yield and reducing the risk of complications.

A retrospective analysis of native kidney biopsies performed at a single center demonstrated that techniques based on ultrasound are both safe and effective. This study highlighted that percutaneous kidney biopsies using USG resulted in adequate tissue yield and had a favorable safety profile. Chung et al. reported no significant differences in post-biopsy complications between ultrasound-marked blind biopsies and real-time USG biopsies performed by nephrologists. This finding underscores the potential for both methods to be safely employed in clinical practice, depending on available resources and expertise.⁴³⁰

Additionally, an observational study conducted in Thailand reviewed 204 kidney biopsies and concluded that real-time ultrasound-guided percutaneous kidney biopsies yielded more adequate tissue and a higher number of glomeruli compared to blind percutaneous kidney biopsies. Importantly, the incidence of complications was comparable between the two methods.⁴³¹

Given these findings, the guidelines prioritize the use of real-time USG for percutaneous kidney biopsies to maximize tissue adequacy and minimize complications. However, in resource-limited settings, where real-time ultrasound may not be available, blind biopsies with ultrasound surface markings are considered a reasonable alternative.

Rationale

Kidney biopsy is a critical diagnostic procedure that requires careful consideration of the patient's position to ensure safety, accuracy, and optimal tissue yield. The prone position, with a pillow or sandbag under the abdomen, is widely recommended for native kidney biopsies. This position helps to splint the kidneys, reducing movement and providing a stable target for biopsy. Using this technique, nephrologists could perform real-time USG biopsies effectively, with no significant difference in post-biopsy complications compared to ultrasound-marked blind biopsies.^{413,431,432,433}

However, obese patients or those with respiratory difficulties may have compromised respiratory function or difficulty lying prone for extended periods. The supine anterolateral position can provide a safer alternative, ensuring adequate oxygenation and patient comfort while still allowing access to the kidney. According to research, this position minimizes respiratory compromise and allows for effective biopsy performance in these populations.^{413,432,434,435}

For kidney transplant biopsies, the supine position is preferred. This position allows easy access to the transplanted kidney, which is typically located in the lower abdomen and minimizes patient discomfort. Expert consensus supports this position due to its practicality and effectiveness in clinical practice.^413,432

In exceptional situations such as intubated, pregnant, or morbidly obese patients, the recommended approach is to use any position that ensures safety and access to the kidney. This flexible guideline acknowledges these unique challenges and emphasizes the importance of adapting the procedure to individual patient needs. Studies have shown that maintaining flexibility in patient positioning can reduce complications and improve biopsy success rates in these complex cases.^413,432

Rationale

The recommendation to use tertiary or unconventional access sites as a last resort following the failure of all conventional access sites or as a temporary measure for patients awaiting kidney transplantation who require the preservation of femoral veins is based on the critical need to maintain viable access options for HD. Conventional access sites are preferred due to their established safety profiles and ease of use; however, when these sites are exhausted, unconventional sites become essential to ensure continued dialysis treatment. Utilizing these sites only in centers with the requisite expertise ensures that the procedures are performed safely and effectively, minimizing potential complications and maximizing benefits. Given the significant technical challenges and high degree of skill required for these procedures, it is strongly recommended to obtain very high-risk consent. Unconventional access site procedures, such as those involving the IVC through trans lumbar, transhepatic, or femoral routes, often involve complex and "blind" techniques that carry substantial risks, including improper catheter placement, vascular injury, and infection. The unconventional VA techniques extend to the creation of AVF and AVG at non-traditional sites. These include arterio-arterial prosthetic loop grafts and right atrial grafts, among others. Such access points are considered when conventional fistulas or grafts are no longer feasible, provided the necessary expertise and infrastructure are available. All these procedures require a high degree of technical skill and commitment from the operating surgeons due to the complexity and potential for complications.⁴³⁶

By ensuring patients provide very high-risk written consent, healthcare providers can guarantee that patients are fully informed about the potential risks and benefits, thereby adhering to ethical standards of patient autonomy and informed decision-making. This thorough consent process is crucial for maintaining trust and transparency between patients and healthcare providers.⁴³⁶

Rationale

Unconventional TCC placement involves inserting the catheter into the IVC through non-traditional approaches, including the trans lumbar, transhepatic, and transfemoral routes. Each procedure is complex and often “blind” requiring a high level of technical skill and carrying significant risk, necessitating very high-risk consent. The catheter tip should ideally be positioned in the right atrium for optimal function, though placement above the iliac veins' confluence in the IVC is acceptable. The trans-lumbar approach accesses the IVC through the right lumbar region, preserving the external iliac vein for potential kidney transplantation.^134,437-440 The transhepatic approach involves inserting the catheter via the hepatic veins, under USG. The right hepatic vein is preferred to avoid vital structures near the portal vein. The transfemoral approach, akin to femoral vein cannulation, is simpler but should be avoided in patients awaiting kidney transplantation due to the need to preserve femoral veins. While these unconventional placements offer a solution for patients with limited access options, their long-term safety and efficacy are not well-documented, underscoring the importance of experienced practitioners performing these high-risk procedures.

Rationale

The utilization of various grafts and fistulas for HD access is driven by the necessity to extend and maximize available vascular sites when traditional options are exhausted or compromised.

Techniques like the Femoro-Saphenous AV Graft and the Saphenous Vein as a conduit provide additional options for creating durable dialysis access in both lower and upper limbs, especially when conventional locations are depleted. These methods, however, require vigilant monitoring for complications such as venous hypertension or graft failure. This underscores the importance of specialized skills and equipment for ensuring successful outcomes.

Lower limb AVFs, utilizing the femoral or saphenous veins transposed subcutaneously, are a viable solution when upper limb sites are unavailable. Thorough preoperative assessment and postoperative care are essential due to the potential for mobility issues and site-specific complications despite good patency rates.^441,442

AAPL grafts, using prosthetic materials or autologous veins, provide a dependable alternative for creating arterio-arterial communications. These grafts are constructed using materials like PTFE and flixene in configurations such as parallel, loop, and omega loop grafts primarily in the upper limbs (brachial to brachial, axillary to axillary).^443-450 Their superior patency rates make them a reliable option, especially when traditional sites are compromised. However, there's a caution against using femoral grafts due to higher risks of limb ischemia and thrombosis, reflecting the need for careful patient selection and monitoring.⁴⁴⁷

Right atrial grafts^451-453 and fistulo atrial grafts^454-456 represent sophisticated options that require invasive procedures such as claviculotomy or sternotomy. Right atrial grafts employing PTFE or autologous grafts create a bypass from upper limb arteries directly to the right atrial appendage.^451-453 This method facilitates a new access point for dialysis but involves complex surgical procedures requiring CTVS expertise. The necessity of facilities equipped with specialized surgical teams limits their use to well-equipped centers, ensuring patient safety and procedural success.

Fistulo Atrial Grafts connect a proximal viable section of an existing AVF to the right atrial appendage, leveraging existing VA for continued HD. This approach helps preserve vascular integrity and extend VA points' usability.^352,353

Each technique and its application are based on clinical evidence, patient anatomy, and the availability of medical expertise and infrastructure, all aimed at optimizing patient outcomes in managing ESKD. These recommendations reflect a balanced approach to patient care, procedural feasibility, and the long-term success of access points.

Acknowledgement

Avatar Foundation is highly appreciative of generous education grant by following organizations.

1. IPCA Laboratories Limited

2. Zydus life Sciences Ltd

3. Mediart Life Science Pvt Ltd

4. Steadfast Medishield Private Limited

5. Orivia Life Science Pvt Ltd

Avatar Foundation

We would like to acknowledge the contributions of the administrative staff of AVATAR Foundation and Avatar India Society, who helped coordinate meetings, compile data, and manage logistics. In particular, we are grateful to Dr. Anupriya Khare Roy (Ph.D.) for compiling, proof reading & formatting and Dr. Mragank Gaur, Dr. Neharita Jasuja, Mr. Ashwani, Ms. Seema Kaul, Mr. Azaruddin, and Mr. Nirmal Maseeh for their invaluable assistance, suggestions and contributions to this project.