Study protocol of a randomized controlled trial of fistula vs. graft arteriovenous vascular access in older adults with end-stage kidney disease on hemodialysis: the AV access trial.

BACKGROUND: Treatment of end-stage kidney disease (ESKD) with hemodialysis requires surgical creation of an arteriovenous (AV) vascular access-fistula (AVF) or graft (AVG)-to avoid (or limit) the use of a central venous catheter (CVC). AVFs have long been considered the first-line vascular access option, with AVGs as second best. Recent studies have suggested that, in older adults, AVGs may be a better strategy than AVFs. Lacking evidence from well-powered randomized clinical trials, integration of these results into clinical decision making is challenging. The main objective of the AV Access Study is to compare, between the two types of AV access, clinical outcomes that are important to patients, physicians, and policy makers. METHODS: This is a prospective, multicenter, randomized controlled trial in adults ≥ 60 years old receiving chronic hemodialysis via a CVC. Eligible participants must have co-existing cardiovascular disease, peripheral arterial disease, and/or diabetes mellitus; and vascular anatomy suitable for placement of either type of AV access. Participants are randomized, in a 1:1 ratio, to a strategy of AVG or AVF creation. An estimated 262 participants will be recruited across 7 healthcare systems, with average follow-up of 2 years. Questionnaires will be administered at baseline and semi-annually. The primary outcome is the rate of CVC-free days per 100 patient-days. The primary safety outcome is the cumulative incidence of vascular access (CVC or AV access)-related severe infections-defined as access infections that lead to hospitalization or death. Secondary outcomes include access-related healthcare costs and patients' experiences with vascular access care between the two treatment groups. DISCUSSION: In the absence of studies using robust and unbiased research methodology to address vascular access care for hemodialysis patients, clinical decisions are limited to inferences from observational studies. The goal of the AV Access Study is to generate evidence to optimize vascular access care, based on objective, age-specific criteria, while incorporating goals of care and patient preference for vascular access type in clinical decision-making. TRIAL REGISTRATION: This study is being conducted in accordance with the tenets of the Helsinki Declaration, and has been approved by the central institutional review board (IRB) of Wake Forest University Health Sciences (approval number: 00069593) and local IRB of each participating clinical center; and was registered on Nov 27, 2020, at ClinicalTrials.gov (NCT04646226).

Kidney dysfunction requiring dialysis is a heterogeneous syndrome: we should treat it like one.

PURPOSE OF REVIEW: Advanced kidney failure requiring dialysis, commonly labeled end-stage kidney disease or chronic kidney disease stage 5D, is a heterogeneous syndrome -a key reason that may explain why: treating advanced kidney dysfunction is challenging and many clinical trials involving patients on dialysis have failed, thus far. Treatment with dialytic techniques - of which maintenance thrice-weekly hemodialysis is most commonly used - is broadly named kidney 'replacement' therapy, a term that casts the perception of a priori abandonment of intrinsic kidney function and subsumes patients into a single, homogeneous group. RECENT FINDINGS: Patients with advanced kidney failure necessitating dialytic therapy may have ongoing endogenous kidney function, and differ in their clinical manifestations and needs. Different terminology, for example, kidney dysfunction requiring dialysis (KDRD) with stages of progressive severity could better capture the range of phenotypes of patients who require kidney 'assistance' therapy. SUMMARY: Classifying patients with KDRD based on objective, quantitative levels of endogenous kidney function, as well as patient-reported symptoms and quality of life, would facilitate hemodialysis prescriptions tailored to level of kidney dysfunction, clinical needs, and personal priorities. Such classification would encourage clinicians to move toward personalized, physiological, and adaptive approach to hemodialysis therapy.

Study protocol for Vascular Access outcome measure for function: a vaLidation study In hemoDialysis (VALID) : A multi-center, multinational validation study to assess the accuracy and feasibility of measuring vascular access function in clinical practice.

BACKGROUND: A functioning vascular access (VA) is crucial to providing adequate hemodialysis (HD) and considered a critically important outcome by patients and healthcare professionals. A validated, patient-important outcome measure for VA function that can be easily measured in research and practice to harvest reliable and relevant evidence for informing patient-centered HD care is lacking. Vascular Access outcome measure for function: a vaLidation study In hemoDialysis (VALID) aims to assess the accuracy and feasibility of measuring a core outcome for VA function established by the international Standardized Outcomes in Nephrology (SONG) initiative. METHODS: VALID is a prospective, multi-center, multinational validation study that will assess the accuracy and feasibility of measuring VA function, defined as the need for interventions to enable and maintain the use of a VA for HD. The primary objective is to determine whether VA function can be measured accurately by clinical staff as part of routine clinical practice (Assessor 1) compared to the reference standard of documented VA procedures collected by a VA expert (Assessor 2) during a 6-month follow-up period. Secondary outcomes include feasibility and acceptability of measuring VA function and the time to, rate of, and type of VA interventions. An estimated 612 participants will be recruited from approximately 10 dialysis units of different size, type (home-, in-center and satellite), governance (private versus public), and location (rural versus urban) across Australia, Canada, Europe, and Malaysia. Validity will be measured by the sensitivity and specificity of the data acquisition process. The sensitivity corresponds to the proportion of correctly identified interventions by Assessor 1, among the interventions identified by Assessor 2 (reference standard). The feasibility of measuring VA function will be assessed by the average data collection time, data completeness, feasibility questionnaires and semi-structured interviews on key feasibility aspects with the assessors. DISCUSSION: Accuracy, acceptability, and feasibility of measuring VA function as part of routine clinical practice are required to facilitate global implementation of this core outcome across all HD trials. Global use of a standardized, patient-centered outcome measure for VA function in HD research will enhance the consistency and relevance of trial evidence to guide patient-centered care. TRIAL REGISTRATION: Clinicaltrials.gov: NCT03969225. Registered on 31st May 2019.

New Devices and Technologies for Hemodialysis Vascular Access: A Review.

In the United States, hemodialysis remains the most common treatment modality for kidney failure, chosen by almost 90% of incident patients. A functioning vascular access is key to providing adequate hemodialysis therapy. Recently, major innovations in devices and technology for hemodialysis vascular access care have rapidly changed the landscape. Novel endovascular devices for creation of arteriovenous fistulas may offer a solution to the barriers encountered in initiating maintenance hemodialysis with a permanent vascular access rather than a central venous catheter (CVC). Furthermore, in the prevalent hemodialysis population, the minimally invasive endovascular arteriovenous fistula procedure should help improve long wait times for vascular access creation, which remains a major barrier to reducing CVC dependence. Bioengineered grafts are being developed and may offer another option to polytetrafluoroethylene grafts. Early studies with these biocompatible grafts are promising, as additional studies continue to evaluate their clinical outcomes in comparison to cryopreserved or synthetic options. Prolonging the vascular access patency with appropriate use of devices such as drug-coated balloons and stent grafts may complement the novel techniques of creating arteriovenous access. Finally, innovative solutions to treat stenosed and occluded thoracic central veins can provide an approach to creating a vascular access and allow patients with exhausted vasculature to remain on hemodialysis. The robust developments in hemodialysis vascular access are likely to change practice patterns in the near future.

KDOQI Clinical Practice Guideline for Vascular Access: 2019 Update.

The National Kidney Foundation's Kidney Disease Outcomes Quality Initiative (KDOQI) has provided evidence-based guidelines for hemodialysis vascular access since 1996. Since the last update in 2006, there has been a great accumulation of new evidence and sophistication in the guidelines process. The 2019 update to the KDOQI Clinical Practice Guideline for Vascular Access is a comprehensive document intended to assist multidisciplinary practitioners care for chronic kidney disease patients and their vascular access. New topics include the end-stage kidney disease "Life-Plan" and related concepts, guidance on vascular access choice, new targets for arteriovenous access (fistulas and grafts) and central venous catheters, management of specific complications, and renewed approaches to some older topics. Appraisal of the quality of the evidence was independently conducted by using a Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach, and interpretation and application followed the GRADE Evidence to Decision frameworks. As applicable, each guideline statement is accompanied by rationale/background information, a detailed justification, monitoring and evaluation guidance, implementation considerations, special discussions, and recommendations for future research.

Identifying critically important vascular access outcomes for trials in haemodialysis: an international survey with patients, caregivers and health professionals.

BACKGROUND: Vascular access outcomes reported across haemodialysis (HD) trials are numerous, heterogeneous and not always relevant to patients and clinicians. This study aimed to identify critically important vascular access outcomes. METHOD: Outcomes derived from a systematic review, multi-disciplinary expert panel and patient input were included in a multilanguage online survey. Participants rated the absolute importance of outcomes using a 9-point Likert scale (7-9 being critically important). The relative importance was determined by a best-worst scale using multinomial logistic regression. Open text responses were analysed thematically. RESULTS: The survey was completed by 873 participants [224 (26%) patients/caregivers and 649 (74%) health professionals] from 58 countries. Vascular access function was considered the most important outcome (mean score 7.8 for patients and caregivers/8.5 for health professionals, with 85%/95% rating it critically important, and top ranked on best-worst scale), followed by infection (mean 7.4/8.2, 79%/92% rating it critically important, second rank on best-worst scale). Health professionals rated all outcomes of equal or higher importance than patients/caregivers, except for aneurysms. We identified six themes: necessity for HD, applicability across vascular access types, frequency and severity of debilitation, minimizing the risk of hospitalization and death, optimizing technical competence and adherence to best practice and direct impact on appearance and lifestyle. CONCLUSIONS: Vascular access function was the most critically important outcome among patients/caregivers and health professionals. Consistent reporting of this outcome across trials in HD will strengthen their value in supporting vascular access practice and shared decision making in patients requiring HD.

Innovations in vascular access for hemodialysis.

Worldwide, hemodialysis remains the prevalent dialysis modality for more than 2 million patients who require well-functioning vascular access for this procedure. Creation of an arteriovenous fistula for long-term hemodialysis was the first innovation since the Scribner shunt and was followed by the development of an arteriovenous graft and catheter. Bioengineered vessels were developed during the last century, but this field has been energized by recent technology relating to the creation of human vessels. Novel endovascular techniques for creating an arteriovenous fistula may resolve some of the logistical issues involved in obtaining a timely arteriovenous fistula. Treatment of access stenosis, infection, and thrombosis has remained suboptimal, and innovative technologies are evolving. Many new approaches are now targeting the biological and mechanical aspects of vascular access, such as creation and maturation of arterial and venous anastomoses, development of a biological conduit for outflow, and negotiating the problems of central vein stenosis. Importantly, processes of access care that have long focused on arteriovenous fistulas are now recognizing the new paradigm, providing a complementary niche to arteriovenous grafts and dialysis catheters in the algorithm for individualized access placement. Cumulatively, to the credit of the multidisciplinary team approach, the long overdue focus on the very existential issue of vascular access for hemodialysis is being approached with newfound evidence-based enthusiasm as the vexing challenges related to regulations and reimbursement in hemodialysis persist. Patient choice and experience, often missed and ignored in the challenging management of an end-stage organ failure, need to stay central as we focus on patient-centered care of vascular access.

Vascular access of last resort.

Exhausted vasculature is not uncommon in patients receiving long-term hemodialysis treatment. Certain patients exhaust their peripheral veins and do not retain the venous capital necessary for fistula creation. Others suffer from severe peripheral arterial disease and despite the presence of adequate venous capital are not able to receive an arteriovenous access successfully. Most importantly, in the case of occluded central veins, the creation of an arteriovenous access in the arms or thighs would be futile, even if peripheral veins and/or arteries were available. Because renal transplant is not readily available, such patients virtually face death in the absence of dialysis therapy. Hence, it is critically important that vascular access options be available to successfully receive renal replacement therapy. This article describes accesses of last resort and provides information vital to nephrologists for discussion with their patients and to surgeons in choosing an optimal option.

Renal Replacement Therapy and Incremental Hemodialysis for Veterans with Advanced Chronic Kidney Disease.

Each year approximately 13,000 Veterans transition to maintenance dialysis, mostly in the traditional form of thrice-weekly hemodialysis from the start. Among >6000 dialysis units nationwide, there are currently approximately 70 Veterans Affairs (VA) dialysis centers. Given this number of VA dialysis centers and their limited capacity, only 10% of all incident dialysis Veterans initiate treatment in a VA center. Evidence suggests that, among Veterans, the receipt of care within the VA system is associated with favorable outcomes, potentially because of the enhanced access to healthcare resources. Data from the United States Renal Data System Special Study Center "Transition-of-Care-in-CKD" suggest that Veterans who receive dialysis in a VA unit exhibit greater survival compared with the non-VA centers. Substantial financial expenditures arise from the high volume of outsourced care and higher dialysis reimbursement paid by the VA than by Medicare to outsourced providers. Given the exceedingly high mortality and abrupt decline in residual kidney function (RKF) in the first dialysis year, it is possible that incremental transition to dialysis through an initial twice-weekly hemodialysis regimen might preserve RKF, prolong vascular access longevity, improve patients' quality of life, and be a more patient-centered approach, more consistent with "personalized" dialysis. Broad implementation of incremental dialysis might also result in more Veterans receiving care within a VA dialysis unit. Controlled trials are needed to examine the safety and efficacy of incremental hemodialysis in Veterans and other populations; the administrative and health care as well as provider structure within the VA system would facilitate the performance of such trials.

Safety of brachial arteriogram using a 3-French dilator to evaluate nonmaturing arteriovenous fistulae.

Nonmaturing arteriovenous fistula remains a hurdle in improving the fistula rate in the hemodialysis population. Timely referral can assist in salvaging fistula with endovascular interventions. Pathology at the inflow segment is frequently encountered as a primary reason for maturation failure. Conventional retrograde angiography can result in poor delineation of the inflow segment and may not be an ideal method for evaluating nonmaturing fistulae. Moreover, the risk of vascular rupture and overzealous diagnosis of accessory veins often result in additional unnecessary therapeutic interventions. Alternatively, a direct brachial arteriogram can provide complete anatomic delineation to perform appropriate endovascular interventions.

Thrombocytopenia in ESRD patients: epidemiology, mechanisms and interventional nephrology perspective.

A well-functioning vascular access is essential for provision of life-sustaining dialysis treatment in patients with end-stage renal disease. Arteriovenous accesses are preferred form of vascular access. Although significant advances have been made in the field of dialysis access, arteriovenous access dysfunction remains the single most important cause of morbidity in ESRD patients. While thrombosis and stenosis of AV access are more frequently seen, hemorrhage from AV access can be life threatening with or without risk of permanent access loss. Aside from anticoagulation for comorbidities, qualitative and/or quantitative platelet abnormalities are often the predisposing factors. We describe an ESRD patient who developed new onset but severe thrombocytopenia due to metastatic small cell neuroendocrine carcinoma of lung. Given her persistent thrombocytopenia and presence of prolonged bleeding from the cannulation sites, a right internal jugular tunneled dialysis catheter was placed for continuation of maintenance dialysis. This review discusses the definition of thrombocytopenia, mechanisms of thrombocytopenia in patients with ESRD and with a special focus on implications of thrombocytopenia on dialysis access interventions. The review underscores the need for consensus with regard to cannulating AV access as well as guidelines specific to dialysis access-related endovascular intervention in the setting of thrombocytopenia and other coagulation abnormalities.

Validating the anatomical landmark technique for bedside tunneled central venous catheter placement in the medical intensive care unit.

BACKGROUND: A non-tunneled dialysis catheter (nTDC) is often the vascular access of choice to initiate dialysis in an intensive care unit (ICU). In the absence of contraindications, if a patient remains dialysis dependent beyond 2-weeks, the options are either to replace the nTDC with another nTDC or convert to a tunneled dialysis catheter (TDC). As a standard of care, TDCs are placed under fluoroscopic guidance. OBJECTIVES: To determine if TDCs and other tunneled central venous catheters (tCVC) can be placed safely using anatomical landmark techniques without the use of fluoroscopy. RESEARCH DESIGN: Subjects that met a predetermined selection criteria underwent placement of tunneled catheters with the use of the anatomical landmark technique. We looked at various outcomes to determine the safety and effectiveness of this technique. SUBJECTS: One hundred eleven TDCs and other tCVCs were placed using the anatomical landmark technique in the intensive care unit. RESULTS: All but one (110/111) of the catheters placed had recommended tip placement confirmed by at least one blinded physician. Major complications encountered were bleeding (two cases), pneumothorax (one case), and line associated blood stream infection (one case). We did find a higher-than-expected rate of "unnecessary procedures" with 18/111 lines placed in patients who did not survive beyond 7 days after placement of the catheter. CONCLUSIONS: Using the anatomical landmark technique for bedside tunneled catheter placement can be an effective approach in the right population.

Education in vascular access.

The successful creation and use of an arteriovenous vascular access (VA) requires a coordinated, educated multidisciplinary team to ensure an optimal VA for each patient. Patient education programs on VA are associated with increased arteriovenous VA use at dialysis initiation. Education should be tailored to patient goals and preferences with the understanding that experiential education from patient to patient is far more influential than that provided by the healthcare professional. VA education for the nephrologist should focus on addressing the systematic and patient-level barriers in achieving a functional VA, with specific components relating to VA creation, maturation, and cannulation that consider patient goals and preferences. A deficit in nursing skills in the area of assessment and cannulation can have devastating consequences for hemodialysis patients. Delivery of an integrated education program increases nurses' knowledge of VA and development of simulation programs or constructs to assist in cannulation of the VA will greatly facilitate the much needed skill transfer. Adequate VA surgical training and experience are critical to the creation and outcomes of VA. Simulations can benefit nephrologists, dialysis nurses surgeons, and interventionalists though aiding in surgical creation, understanding of the physiology and anatomy of a dysfunctional VA, and practicing cannulation techniques. All future educational initiatives must emphasize the importance of multidisciplinary care to attain successful VA outcomes.

Acute hemodialysis catheter follows the path of least resistance.

The placement of large bore double-lumen catheters for hemodialysis (HD) is one of the most frequent procedures performed in HD patients. However, these procedures are associated with complications, the most common being catheter malposition. In this context, catheter deviation to the left superior intercostal vein (LISV) is a very uncommon malposition, which must be differentiated from intrathoracic extravascular catheter lodgment. We report a case of an adult male patient on hemodialysis who presented with a thrombosed arteriovenous fistula and requiring urgent HD. His past medical history included hemophilia, allergy to contrast media, and multiple previous central vein catheterizations. A non-tunneled HD catheter was placed without any difficulty in the left internal jugular vein. However, the arterial lumen failed to pull any blood with free flow in the venous lumen. A chest X-ray revealed a surprising finding. The malpositioned catheter was removed successfully without any complications.

Salvage of the existing venotomy site and tunnel: Redeeming the "Fallen dialysis catheter".

Accidental extrusion of tunneled hemodialysis (HD) catheter leaves the dialysis patient without a vascular access and creates an emergency. The common practice is to insert a new catheter via a new venotomy site and a new tunnel. We highlight a lesser-known intervention technique that helps preserve the limited central venous vascular access sites needed to provide dialysis. A 42-year-old man with end stage kidney disease on HD through a right internal jugular vein (RIJV) tunneled hemodialysis catheter (TDC) was referred 1-day after he accidently pulled his catheter following the removal of butterfly wing sutures. The TDC had been in place for 2 months. On examination, the catheter exit site was not infected. After sterile skin preparation the exit site and the tunnel were cleaned with betadine impregnated Q-tips. An 0.035″ hydrophilic guidewire was advanced through the existing venotomy site over a 5F directional catheter under fluoroscopic guidance. The catheter over the guidewire was advanced through the tunnel towards the previous venotomy site in the RIJV. The exact position of the guidewire and catheter was confirmed by injecting contrast. The angled catheter was then maneuvered inferiorly towards the superior vena cava and the wire was placed in the inferior vena cava. A new TDC was advanced over the guidewire through the existing tunnel and the catheter tip was positioned into the mid-right atrium. The procedure was uneventful and TDC was functioning well at 1-month follow-up review. In conclusion, the case highlights the safety of an underutilized practical approach to achieving safe and quick access for dialysis in patients with accidental loss of TDC. The technique described herein, avoids the need to select a new venotomy site, improves patient satisfaction by minimizing procedure related discomfort due to alleviating the need to create a new tunnel, and optimizes resources used for the procedure.

Tunneled femoral dialysis catheter: Practical pointers.

One of the most challenging aspects of providing end-stage kidney disease care is to achieve adequate long-term access to the bloodstream to support hemodialysis (HD) therapy. Although upper extremity arteriovenous fistula remains the vascular access of choice for patients on HD, complications such as central venous stenosis, access thrombosis, or exhaustion of suitable access sites in the upper extremity, ultimately result in pursuing vascular access creation in the lower extremity. The current review focuses on the indications, contraindications, and clinically relevant practical procedural tips to successfully place a tunneled femoral dialysis catheter. The review highlights some of the prevailing misconceptions regarding femoral catheter placement practices.