Comparison between Surgical and Endovascular Hemodialysis Arteriovenous Fistula Interventions and Associated Costs

Creating an Ellipsys percutaneous arteriovenous fistula after a failed ipsilateral WavelinQ fistula: A case report of an endovascular approach for access restoration

The introduction of devices for endovascular dialysis access creation (WavelinQ and Ellipsys) offers practitioners more options for access management in dialysis patients. Especially in terms of reducing the usage of central venous catheters, a native fistula is desirable as an initial dialysis access. We present a case in which a failed WavelinQ type fistula was reactivated using the Ellipsys procedure on the same arm. This specific rescue method is based on the idea that the proximal part of an endoAVF from an earlier WavelinQ procedure which resulted in adequately dilated veins, comprising the perforating vein, may allow a subsequent Ellipsys procedure. This case report shows how the use of endovascular techniques such as WavelinQ and Ellipsys can be incorporated in a clinical context and create new options for the patient.

Existing and Evolving Therapies for Arteriovenous Fistula and Graft Dysfunction

A functional vascular access (VA) is of paramount importance to patients on hemodialysis therapy. While arteriovenous fistula (AVF) remains the preferred VA, their long-term patency is unpredictable. A dysfunctional VA contributes to a high morbidity rate, an increased susceptibility to major adverse cardiovascular events, recurrent hospitalization, and a poor quality of life. The recent innovations in devices and technologies have significantly expanded our options to create and prolong VA patency. Endovascular devices such as WavelinQ and Ellipsys are recent additions to creating a VA. The endovascular creation of AVF helps reduce the wait time and potentially avoids or reduces the duration of catheter use. The bioengineered graft and immediate access arteriovenous graft offer reasonable alternatives in a select group of patients. There is growing evidence that covered stents and drug-coated balloons offer options to prolong the VA patency. Finally, the role of stem cell therapy in VA is currently being explored. This article presents a comprehensive review of the conventional and current developments in the management of a dysfunctional VA.

What are the reported procedural costs of vascular access surgery?

INTRODUCTION

Since the inception of arteriovenous grafts (AVG) as a novel technique, there has been greater emphasis on the assessment of outcomes rather than costs. Gross-costing methods over-simplify vascular access surgery and do not reflect the true costs of the service, preventing accurate cost-effectiveness analysis. The aim of this study is to assess the reporting of procedural costs of arteriovenous access creation in economic analyses of vascular access surgery, and to compare the reported costs of the two most performed procedures - arteriovenous fistula (AVF) and arteriovenous graft (AVG).

METHODS

This systematic review included studies reporting a per-procedure cost for AVF or AVG creation. Costs were adjusted from original to target price year using a Gross Domestic Product (GDP) deflator index and converted to 2021 US Dollars using conversion rates based on purchasing power parities.

RESULTS

The results demonstrate wide discrepancy in the reported procedural costs of arteriovenous access creation. Most of the data represents retrospectively observed costs rather than prospective data collected on an intention-to-treat basis. Charges are frequently presented in lieu of costs, and aggregated gross-costing methodology predominates rather than more accurate micro-costing.

CONCLUSION

Future micro-costing studies of vascular access surgery are essential to allow a greater understanding of cost-drivers and allow accurate cost-effectiveness analysis.

Percutaneous arteriovenous fistula creation in the management of severe Hemophilia A and end-stage kidney disease needing hemodialysis access, and beyond

With the contemporary KDOQI, a patient-focused approach in vascular access care is emphasized more than ever when planning RRT. Nevertheless, functional vascular access continues to be the Achilles' heel for successful hemodialysis in specific patient sub-groups, such as the Hemophilia-A population. The newer percutaneous endovascular approach is a safer alternative when conventional surgical AVF poses high bleeding risks perioperatively, which subsequently prevents ESKD patients to have desired permanent dialysis access. This article presents the case of a 45-year-old male with severe Hemophilia-A, who has been dialysis-dependent due to diabetic kidney disease and hypertension. Due to the severity of his progressively worsening bleeding disorder, his previous surgeries to treat other comorbidities have been complicated and involved challenging peri-operative treatment courses that include blood and factor VIII infusions, bleeding wounds, along with prolonged hospital stays. With the fear of bleeding diathesis, a conventional surgical AVF was not pursued, which has left him with a prolonged tunneled CVC while not being considered a candidate for peritoneal dialysis. We offered the patient a left arm percutaneous endovascular AVF creation with the WavelinQ™ 4F Endo-AVF system as an alternative option for his permanent hemodialysis access. An Endo-AVF was created bloodlessly between the left radial artery and lateral radial vein percutaneously with only two 4-French accesses at left wrist. The patient has been receiving full sessions of hemodialysis with expected flow rates and free of the CVC since. Likely the first case of such utilization reported, the utilization of percutaneous Endo-AVF for this patient has suggested not only that the endovascularly created AVF offers a good alternative dialysis access for hemophilia A patient populations, but also due to this technology's unique features, it can be potentially employed in other situations, such as needs for reliable and chronic venous accesses and blood product exchanges.

Cost-effectiveness analysis of endovascular vs surgical arteriovenous fistula creation in the United States

OBJECTIVE

In the United States, an estimated $2.8 billion annually is spent on vascular access and its complications. Endovascular arteriovenous fistula (endoAVF) creation is a novel, minimally invasive alternative to traditional surgical AV fistula (sAVF) creation in ≤60% of patients. Although cost effective in single-payer systems, the clinical and financial impact of endoAVF in the United States remains uncertain.

METHODS

We constructed a decision tree followed by a probabilistic cohort state-transition model to study the cost effectiveness of endoAVF vs sAVF creation. We conducted a systematic review to obtain input parameters including technical success, maturation, patency, and utility values. We derived costs from the Medicare 2022 fee schedule and from the literature. We used a 5-year time horizon, an annual discount rate of 3% for costs and utilities (measured in quality-adjusted life-years [QALYs]), and the common willingness-to-pay threshold of $50,000. One-way and Monte Carlo probabilistic sensitivity analyses were performed varying technical success, patency, reintervention, cost, and utility parameters.

RESULTS

In the base-case scenario, endoAVF ($30,129 average per-person costs, 2.19 QALYs gained, 65% patent at 5 years) was not cost effective compared with sAVF ($12.987 average per-person costs, 2.11 QALYs gained, 66% patent at 5 years), generating an incremental cost-effectiveness ratio of $227,504 per QALY gained. In one-way sensitivity analyses, endoAVF becomes cost effective when the initial cost of sAVF creation exceeds endoAVF by ≥$600 (eg, if endoAVF creation costs ≤$3000 relative to the base-case sAVF cost of $3600), the additional QALYs gained from endoAVF exceeds 0.12 QALYs/year (eg, 0.81 QALYs gained/year from endoAVF compared with base-case sAVF 0.69 QALYs/year), the endoAVF maturation rate is >90% (base case 78%), or the sAVF maturation rate is <65% (base case 78%). Probabilistic sensitivity analysis demonstrated that sAVF remained the optimal strategy in 71% of iterations.

CONCLUSIONS

EndoAVF is not cost effective compared with sAVF when modeling 5-year outcomes. The main driver of sAVF remaining cost effective is the four times higher up-front cost for endoAVF creation, as well as a relatively low additional increase in quality of life for endoAVF. It will be important to establish how the endoAVF learning curve contributes to upfront costs and, given the annual cost attributed to vascular access nationally, a randomized controlled trial is warranted.

Percutaneous Creation of Hemodialysis Fistulas

Non-surgical, percutaneous, or endovascular hemodialysis arteriovenous creation represent an evolution of access creation away from traditional surgical fistulas. These fistulas are additional to surgical alternatives and published studies with the two commercially available devices suggest positive outcomes in terms of technical success, maturation, functionality, and patency. Relevant published studies are presented, and other considerations related to these new devices/procedures are also summarized.

Early clinical experience and comparison between percutaneous and surgical arteriovenous fistula

BACKGROUND

Percutaneous arteriovenous fistula (pAVF) has been recently developed as an alternative to surgical AVF (sAVF). We report our experience with pAVF in comparison with a contemporaneous sAVF group.

METHODS

Charts of all 51 patients with pAVF performed at our institution were analyzed retrospectively, in addition to 51 randomly selected contemporaneous patients with sAVF (2018-2022) with available follow-up. Outcomes of interest were (i) procedural success rate, (ii) number of maturation procedures required, (iii) fistula maturation rates, and (iv) rates of tunneled dialysis catheter (TDC) removal. For patients on hemodialysis (HD), sAVF and pAVF were considered mature when the AVF was used for HD. For patients not on HD, pAVF were considered mature if flow rates of ≥500 mL/min were documented in superficial venous outflow; for sAVF, documentation of maturity based on clinical criteria was required.

RESULTS

Compared patients with sAVF, patients with pAVF were more likely to be male (78% vs 57%; P = .033) and less likely to have congestive heart failure (10% vs 43%; P < .001) and coronary artery disease (18% vs 43%; P = .009). Procedural success was achieved in 50 patients with pAVF (98%). Fistula angioplasties (60% vs 29%; P = .002) and ligation (24% vs 2%; P = .001) or embolization (22% vs 2%; P = .002) of competing outflow veins were more frequently performed on patients with pAVF. The surgical cohort had more planned transpositions (39% vs 6%; P < .001). When all maturation interventions were combined, pAVF required more maturation procedures, but this was not statistically significant (76% vs 53%; P = .692). When planned second-stage transpositions were excluded, pAVF had a statistically significant higher rate of maturation procedures (74% vs 24%; P < .001). Overall, 36 pAVF (72%) and 29 sAVF (57%) developed mature fistulas. This difference, however, was not statistically significant (P = .112). At the time of AVF creation, 26 patients with pAVF and 40 patients with sAVF were on HD, all through use of a TDC. Catheter removal was recorded in 15 patients with pAVF (58%) and 18 patients with sAVF (45%) (P = .314). The mean time until TDC removal in pAVF group was 146 ± 74 days, compared with 175 ± 99 in the sAVF group (P = .341).

CONCLUSIONS

Compared with sAVF, rates of maturation after pAVF seem to be similar, but this result may be related to the higher intensity of maturation procedures and patient selection. An analysis of appropriately matched patients will assist in elucidating the possible role of pAVF vis-a-vis sAVF.

The evolving panorama of vascular access in the 21st century

There are three major types of hemodialysis vascular access: hemodialysis catheters, arteriovenous grafts, and arteriovenous fistulas. Arteriovenous fistulas provide the best access due to their reliability and long-term patency. They are recommended by the current Kidney Disease Outcomes Quality Initiatives (K-DOQI) guidelines; however, not all patients benefit from arteriovenous fistulas due to poor maturation or a lack of adequate vasculature. Currently, hemodialysis is initiated via catheters in the majority of patients. Catheters are associated with high morbidity and mortality due to infection, lower quality of dialysis, and the development of central vein stenosis. The varied responses of patients to the different access types exemplify the need to choose the "right access for the right patient" based on scores that can predict death risk and progression of chronic kidney disease. Additionally, vascular access, often referred to as the "Achilles' heel" of hemodialysis patients, represents a significant percentage of the Medicare budget that continues to increase yearly. The purpose of this paper is to review the current literature on the management of vascular access complications and infection treatment and prevention. The paper also explores emerging research regarding the devices and methods to improve access outcomes such as early cannulation arteriovenous grafts, endovascular arteriovenous fistula creation, and regenerative grafts with resorbable scaffolds, among others. The data were collected through literature searches via PubMed, Athens and web search engines.

Endovascular Arteriovenous Fistula Creation-Review of Current Experience

Functioning vascular access is an essential element for life-saving hemodialysis therapy. A surgically-created arteriovenous fistula has been considered the best option for many years. Recently, two manufacturers developed systems for percutaneous/endovascular creation of an arteriovenous fistula (WavelinQ and Ellipsys). We provide a review of the available experience with these systems and discuss advantages and disadvantages.

Adapting a Dialysis Service for Delivery of Percutaneous Arteriovenous Fistulas

The percutaneous arteriovenous fistula (pAVF) is an exciting and novel addition to the vascular access options available to patients with end-stage kidney disease who require dialysis. Early clinical results have been promising, with high rates of maturation and low rates of reintervention. To successfully adapt an existing hemodialysis service to include the provision of pAVF formation, it is essential to identify and align the interests of key clinical and nonclinical stakeholders. Only through strong collaboration can the service be supported. The authors provide a comprehensive overview of the planning fundamentals required, including the referral pathway, screening and clinical assessment, and practical procedural elements and considerations, as well as follow-up requirements such as cannulation, fistula surveillance, and maintenance. Key staffing requirements are highlighted, including those pertaining to vascular US screening and dialysis nurse training. A broad and structured planning approach ensures that the entire network of key stakeholder interests is included and provides a strong foundation for a compelling business plan to attract the necessary funding and managerial support for the service. The authors present a systematic framework of the essential considerations necessary to facilitate the planning, funding, and ultimately delivery of a successful pAVF service. Online supplemental material is available for this article. ^©RSNA, 2022.

Percutaneous endovascular arteriovenous fistula: A systematic review and meta-analysis

Objective

Currently, percutaneous endovascular creation of arteriovenous fistula (AVF) shows excellent outcomes. However, few systematic research evidence to support clinical decision making on the benefit of endovascular AVF is available. The purpose of this study was to evaluate the efficacy and safety of endovascular AVF (endoAVF) in patients with renal failure.

Methods

We searched the Medline, Embase, Cochrane Library, and ClinicalTrials.gov databases for studies on endovascular or endovascular versus surgery for the creation of AVF. Two reviewers independently selected studies and extracted data. A systematic review and meta-analysis were performed by Review Manager 5.4 software (Revman, The Cochrane Collaboration, Oxford, United Kingdom) and Stata 15.0 (Stata Corp, College Station, TX, United States).

Results

A total of 14 case series and 5 cohort studies, with 1,929 patients, were included in this study. The technique success was 98.00% for endoAVF (95% CI, 0.97–0.99; I² = 16.25%). There was no statistically significant difference in 3 cohort studies between endovascular and surgical AVF for procedural success (OR = 0.69; 95% CI, 0.04–11.98; P = 0.80; I² = 53%). The maturation rates of endoAVF were 87.00% (95% CI, 0.79–0.93; I² = 83.96%), and no significant difference was observed in 3 cohort studies between the 2 groups (OR = 0.73; 95% CI, 0.20–2.63; P = 0.63; I² = 88%). Procedure-related complications for endoAVF was 7% (95% CI, 0.04–0.17; I² = 78.31%), and it did not show significant difference in 4 cohort studies between the 2 groups (OR = 1.85; 95% CI, 0.37–9.16; P = 0.45; I² = 59%).

Conclusion

The endovascular creation of AVF is potentially effective and safe. These important data may provide evidence to support clinicians and patients in making decisions with endovascular AVF. But further research is great necessary due to lack of randomized controlled studies.

Electric-Field-Based Guidance for Percutaneous Catheter Vessel Crossing

Percutaneous procedures to divert blood flow from one blood vessel to another can be performed with intravascular catheters but demand a method to align a crossing needle from one vessel to another. Fluoroscopic imaging alone is not adequate, and it is preferable to have a sensor on one catheter that detects the correct alignment of an incoming needle. This can be implemented by generating dipole electric fields from the crossing catheter which are detected by a receiving catheter in the target vessel and, thus, can calculate and display the degree of alignment, permitting the operator to rotate the crossing catheter to guarantee alignment when deploying a crossing needle. Catheters were built using this concept and evaluated in vitro. The results show that accurate alignment is achieved, and a successful crossing can be made. The concept is being further developed for further clinical evaluation.

Percutaneous Hemodialysis Fistula Creation

Two devices have been recently introduced to European Union and North American clinical practice that allow for percutaneous creation of autogenous hemodialysis fistulas (pAVF). Although there are similarities between the devices, there are many differences. Adoption of either or both technologies by an interventionalist may be determined by the individual's comfort with the device. Importantly, current and future outcomes will shape acceptance and use of these devices. This review focuses on the similarities and differences of each device, the procedures, published outcomes to date and their interpretation and other clinical considerations towards initiation of a successful pAVF program.

Long Term Results from The Pivotal Multicenter Trial of Ultrasound Guided Percutaneous Arteriovenous Fistula Creation for Hemodialysis Access

PURPOSE

To report the five-year results from the Pivotal Multicenter Trial of Ultrasound Guided Percutaneous Arteriovenous Fistula (pAVF) Creation for Hemodialysis Access.

MATERIALS AND METHODS

Retrospective review of 107 intent-to-treat (ITT) patients from the pivotal trial provided a long-term follow-up population (LTP) of 85 patients followed a median 50 months (range 12-60). Data evaluated in the LTP group were fistula maturation and use, secondary procedures, and complications. Kaplan-Meier analysis of primary, primary assisted, cumulative patency, and functional patency (time from two-needle to abandonment) were performed for the ITT population.

RESULTS

In the LTP 99% (84/85) of fistulas were mature with 99% (78/79) of patients requiring hemodialysis using their pAVF. Sustained fistula use (two-needle cannulation at prescribed rate, 2/3 sessions) was achieved in 92% (78/85) of patients, with seven patients never using their pAVF because not on dialysis (n=4), peritoneal dialysis (n=2), and refusing to use fistula (n=1). Fistula maintenance was required in 31.8% (27/85) of patients and included fistula dysfunction (21.2%), thrombosis (5.9%), cannulation injury (12.9%), and arm swelling (4.7%). The number of procedures performed per patient per year (PPPY) to maintain function and patency was 0.32 (91/288) for years 2-5. The cumulative patency was 89.5%, 88.4%, 88.4%, 85.6%, and 82.0% years 1-5, respectively. The functional patency was 91.8% at the end of the study. There were no major complications related to pAVF during long-term follow-up CONCLUSION: Percutaneous fistulae have provided clinically effective and durable access for hemodialysis with low complications. Continued use and evaluation of pAVF is warranted.

A Comparison Between the Efficacy and Safety of Endovascular Arteriovenous Fistula Creation and Surgical Fistula Creation: A Systematic Review and Meta-Analysis

An endovascular arteriovenous fistula is a recent technological advancement in hemodialysis vascular access. This systematic review and meta-analysis aimed to investigate the efficacy and safety of endovascular arteriovenous fistula (eAVF) creation compared with surgical arteriovenous fistula (sAVF) creation among patients with chronic kidney disease.

We searched Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Clinical Trials.gov, and the WHO International Clinical Trials Registry Platform until May 2021 to perform meta-analyses using random-effects models. Pre-specified primary outcomes were fistula maturation, procedure-related complications, and patient satisfaction. Secondary outcomes were procedural technical success, procedure time, all adverse events, and medical expenditure. The risk of bias in non-randomized studies of the interventions assessment tool, and the Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) approach were used to assess the quality of individual studies and the body of evidence, respectively.

In seven studies including 860 patients, endovascular arteriovenous fistula creation had little to no effect on fistula maturation (odds ratio, 0.58; 95% confidence intervals, 0.05 to 6.91). Meta-analysis could not be performed for procedure-related complications and patient satisfaction due to insufficient data. For secondary outcomes, endovascular arteriovenous fistula resulted in a slight to no difference in procedural technical success (odds ratio, 0.69: 95% confidence intervals, 0.04 to 11.98) and all adverse events (odds ratio, 6.31; 95% confidence intervals, 0.64 to 62.22). Endovascular fistula creation incurred less medical expenditure than sAVF (mean difference, USD 12760; 95% confidence intervals, -19710 to -5820). Meta-analysis for procedure time was not performed because one of the studies had a critical risk of bias. All of these outcomes were of low certainty of evidence or very low certainty of evidence.

There was limited evidence for supporting endovascular arteriovenous fistula creation over conventional surgical arteriovenous fistula creation for patients with chronic kidney disease. Multicenter randomized controlled trials are needed to confirm the efficacy and safety of eAVFs in selected populations.

Percutaneous arteriovenous fistula creation

The first percutaneous systems used to create an arteriovenous fistula for hemodialysis were approved by the US Food and Drug Administration in 2018 and included the Ellipsys and WavelinQ devices. Early results and longer-term studies of these catheter-based devices suggest that they offer important benefits and potentially improved outcomes in patients with appropriate anatomy. The deep communicating vein in the cubital fossa and its relationship to the proximal radial artery or proximal ulnar artery are key vascular elements of both systems. The devices differ significantly in technical design, energy source, imaging requirements, procedure times, catheters, access vessel sites, and techniques. We review the two approved percutaneous arteriovenous fistula devices, including technical considerations, selecting the appropriate patient, postoperative evaluation, interventions, outcomes, potential complications, and cannulation issues.

Endovascular Arteriovenous Fistula Creation: A Review

Endovascular arteriovenous fistula (endoAVF) creation offers a minimally invasive method for the formation of arteriovenous shunts utilized for hemodialysis. Currently, there exist two similar yet unique devices: WavelinQ and Ellipsys. This review analyzes the anatomy, pre- and postoperative considerations, fistula creation methods, and outcomes associated with endoAVF. Currently, data are limited with regard to clinical efficacy of endoAVFs when compared to surgical AVFs. However, early data suggest endoAVFs are a useful technique in the creation of AVFs.

Novel Clinical Therapies and Technologies in Dialysis Vascular Access

The hemodialysis population continues to grow. Although procedures for dialysis have existed for >60 years, significant challenges with vascular access to support hemodialysis persist. Failure of arteriovenous fistulas (AVFs) to mature, loss of AVF and graft patency, thrombosis, and infection hinder long-term access, and add extra health care costs and patient morbidity. There have been numerous innovations over the last decade aimed at addressing the issues. In this study, we review the literature and summarize the recent evolution of drug delivery, graft development, minimally invasive AVF creation, and stem-cell therapy for hemodialysis access.

A Comparison of Outcomes Between Open and Endovascular Arteriovenous Access Creation for Hemodialysis

OBJECTIVE

Preliminary outcomes for percutaneous endovascular autogenous access (endoAVF) have shown promising results; however, comparisons with surgical cohorts in dialysis populations are lacking. This study compares autogenous arteriovenous access created with the EverlinQ endoAVF system with accesses created by conventional surgical technique with respect to functional and patency related outcomes.

METHODS

This is a multicenter, retrospective review of autogenous arteriovenous accesses entered into a prospective database. Patients receiving radiocephalic, brachiocephalic, or endoAVF arteriovenous accesses between 2014 -2019 were included. Autogenous access maturation, primary patency, secondary patency, steal syndrome, and re-interventions were collected and analyzed using standard statistical and survival analyses.

RESULTS

A total of 369 accesses were created during the study period, including 61 endovascular accesses, 171 radiocephalic accesses, and 137 brachiocephalic accesses (median follow-up 17 months; range 1 - 71 months). Maturation failure at the end of follow-up was 27±6%, 27±5%, and 18±4% for endovascular, radiocephalic, and brachiocephalic accesses, respectively (p =.049 for brachiocephalic vs. endovascular accesses). Primary patencies at 12 and 24 months were 42±5% and 32±7% for endovascular accesses, 43±4% and 24±4% for radiocephalic accesses, and 42±4% and 29±4% for brachiocephalic accesses (p=.906). Secondary patencies at 12 and 24 months were 68±6% and 60±7% for endovascular accesses, 75±3% and 67±4% for radiocephalic accesses, and 91±3% and 81±4% for brachiocephalic accesses (p=.006 for brachiocephalic vs. endovascular accesses). There were no statistically significant differences in ischemic steal syndrome (3.3%, 4.1% and 8.0%; p=.229) or total reinterventions/year (1.0±3.1, 0.9±1.8, and 1.2±1.8; p=.289) for endovascular, radiocephalic, or brachiocephalic arteriovenous accesses, respectively.

CONCLUSIONS

EndoAVF compare favorably with respect to maturation and patency compared with surgically created accesses in a real-world cohort. Outcomes and reintervention rates are similar to conventional radiocephalic arteriovenous accesses, but are inferior with respect to patency and maturation to brachiocephalic accesses.

Endovascular arteriovenous fistulas- are they the answer we haven't been looking for?

INTRODUCTION

Surgically created arteriovenous fistulas are the accepted gold standard for the establishment of hemodialysis access in patients requiring dialysis. However, primary and maturation failures may limit their usage. Recent advances in endovascular technology have resulted in the creation of devices for endovascular arteriovenous fistula formation. These devices may offer an additional or alternative approach to fistula formation in patients with end-stage kidney disease.

AREAS COVERED

This review describes the limitations of surgical arteriovenous fistulas and the endovascular devices currently available. The review covers initial trial data and subsequent studies examining their use.

EXPERT OPINION

Early results achieved with endovascular fistula formation are encouraging. Current limitations of this technology include anatomic suitability and a high rate of re-interventions required to establish maturity. Greater uptake of the technology will also require a review of long-term outcomes in larger patient cohorts.

Initial Outcomes Following Introduction of Percutaneous Arteriovenous Fistula Program with Comparison to Historical Surgically Created Fistulas

BACKGROUND

Recently, there has been an abundance of encouraging data regarding the creation of percutaneous arteriovenous fistulas. Despite promising data regarding their clinical maturation, a paucity of data exists which provides direct comparison between percutaneously created AVFs (pAVF) and open surgically created AVFs (sAVF). This study has 2 primary objectives: First, to compare clinical outcomes of pAVFs to sAVFs, with emphasis on clinical maturation and frequency of postoperative interventions to facilitate maturation. Second, to contribute toward the evidence-based incorporation of the pAVF procedure into the hemodialysis access algorithm.

METHODS

A single-center retrospective review was performed on all consecutive patients undergoing surgically created brachiocephalic arteriovenous fistula (BC-AVF, sAVF group) from January 1, 2018 to December 31, 2018 and Ellipsys-created percutaneous arteriovenous fistula (pAVF group) from January 1, 2019 to December 31, 2019. Comparative analysis between groups was performed.

RESULTS

A total of 24 patients underwent Ellipsys-created pAVF with mean age of 56.7 ± 22.6 years (12 males [50%], 12 females [50%]) and 62 patients underwent surgically created BC-AVF with mean age of 62.5 ± 13.2 years (32 males [52%], 30 females [48%]). Both the pAVF and sAVF groups had comparable mean operating times (60 ± 40 vs. 56 ± 25 min, P = 0.67) and frequency of procedural technical success (23 [96%] vs. 62 [100%], P = 0.28), respectively. The pAVF group had a lower clinical maturation rate (12 [52%] vs. 54 [87%], P = 0.003) and a higher primary failure rate (9 [39%] vs. 6 [10%], P = 0.003) when compared to the sAVF group. The pAVF group had an increased overall rate of undergoing a postoperative intervention (18 [78%] vs. 13 [21%], P< 0.001), as well as an increased number of total postoperative interventions (1.1 ± 0.9 vs. 0.3 ± 0.6 interventions, P< 0.001) compared to the sAVF group. Percutaneous transluminal angioplasty of the juxta anastomotic segment was the most prevalent postoperative intervention performed in the pAVF group and occurred at a significantly increased frequency when compared to the sAVF group rate (13 [57%] vs. 5 [8%], P< 0.001).

CONCLUSIONS

In our single-center retrospective review, patients undergoing Ellipsys-created pAVF in the first year following introduction of percutaneous endovascular had inferior rates of clinical maturation and underwent more postoperative interventions when compared to historical patients undergoing surgically created BC-AVF. Outcome discrepancies compared to previously reported Ellipsys data demonstrate a need for further studies examining the practical translatability of the pAVF.

Trends in Procedures to Initiate Renal Replacement Therapy among People Living with Spina Bifida

PURPOSE

Given the increasing prevalence of chronic kidney disease in people with spina bifida, we sought to determine if this is associated with an increase in end stage kidney disease. We examined population based data to measure the frequency of procedures to establish renal replacement therapy-a marker for end stage kidney disease-among patients with spina bifida.

MATERIALS AND METHODS

We used the Healthcare Cost and Utilization Project State Inpatient Database and State Ambulatory Surgery and Services Database from Florida, Kentucky, Maryland and New York (2000 to 2014), which include encounter level data. With a diagnosis code based algorithm we identified all procedural encounters made by patients with spina bifida. We determined the percentage of these encounters that were for facilitating renal replacement therapy (ie arteriovenous anastomosis, renal transplantation). We assessed for changes over time in this percentage with the Cochran-Armitage trend test. Bivariate analysis was performed using chi-square test.

RESULTS

Of all procedures performed on patients with spina bifida over this time the proportion of procedures performed to establish renal replacement therapy significantly decreased in both the inpatient and outpatient settings (p=0.042 and p <0.001, respectively). People with spina bifida undergoing procedures to establish renal replacement therapy were, on average, young adults (mean age 34.5 and 36.0 years) with a high prevalence hypertension (75.8% of inpatients, 68.6% of outpatients).

CONCLUSIONS

The frequency of surgeries to initiate renal replacement therapy among people with spina bifida undergoing procedures is low and is not increasing. This highlights the importance of consistent care throughout adolescence and young adulthood, and hypertension screening.

Preoperative assessment for percutaneous and open surgical arteriovenous fistula creation in patients for haemodialysis

Preoperative assessment prior to surgical arteriovenous fistulas (AVFs) including ultrasound-guided mapping has been shown to have beneficial effects on their immediate success as well as early outcomes. This has led to their wide acceptance and adoption however clinical practice criteria is variable and is reflected in variabilities in practice. When transposing this to percutaneously created endovascular AVFs (endoAVFs), variable preoperative assessment criteria could equally result in variable practice and potentially subsequent and expectant outcomes. We aimed to review literature on reported validated methodologies and workflows of preoperative assessment for surgical AVF creation as reported in highest levels of available evidence, specifically randomized controlled trials. Published practice recommendations and guidelines on best clinical practice as well as systematic reviews and meta-analyses of published studies were also reviewed. Data on practice methodology from identified trial publications and protocols was collated and a summative narrative synthesis was carried out which compared these methodologies to additional assessments that may be required when targeting assessment for percutaneous endoAVF formation, based on our units experience as part of an international multicentre trial. In this review we present a brief overview of published literature and guidelines and propose a unified and uniform workflow for preoperative assessment for surgical AVFs and endoAVFs to aide clinical and imaging practice.

Initial experience with the Ellipsys Vascular Access System for percutaneous arteriovenous fistula creation in adolescents: A case report

This retrospective, single center, case report describes the first use of the Ellipsys Vascular Access System for percutaneous arteriovenous fistula (pAVF) creation in children. Two adolescent (<20 year of age) patients (18 and 19-year-old females), one of whom was developmentally delayed, were not considered candidates for traditional surgical arteriovenous fistula creation. pAVF creation was successful in both patients using the Ellipsys device and physiologic maturation of the fistula was achieved within 8 weeks of creation with subsequent 2 needle cannulation. No complications or adverse events were encountered. pAVF creation with the Ellipsys device can be safely performed in adolescents. Further studies will be needed to validate the expanded use of these devices in children.

Impacts of age, diabetes, gender, and access type on costs associated with vascular access among Chinese patients on hemodialysis

OBJECTIVES

Examine the impacts of age, diabetes, gender, and access type on vascular access (VA) associated costs among Chinese hemodialysis (HD) patients.

METHODS

We retrospectively included patients whose first permanent VA was created at the West China Hospital. Clinical characteristics, maturation, intervention, utilization, and exchange of every VA, as well as VA-related infection were collected. The study period for each patient was from HD initiation to the last follow-up. VA-related costs, including those for placement and intervention procedures, were calculated according to the standards set in 2019 for Chinese tertiary hospitals. Mann-Whitney U and Chi-square tests were conducted for comparisons between groups.

RESULTS

A total of 358 Chinese HD patients experienced functionally 143 arteriovenous fistula (AVF), 22 arteriovenous graft (AVG), and 439 tunneled cuffed central venous catheter (tcCVC) during a median study period of 26 (IQR 13-44) months, of which 42.5% used more than one permanent VA. The median annual VA-related cost in the groups of age >75 years and ⩽75 years, diabetes and non-diabetes, male and female, was $525 and $397 (p = 0.016), $459 and $462 (p = 0.64), $476 and $445 (p = 0.94), respectively. The median monthly costs for AVF ($18), AVG ($289), and tcCVC ($37) were significantly different.

CONCLUSION

HD patients aged >75 years had significantly higher annual VA-related costs. However, the annual VA-related costs did not differ across the diabetes groups or the gender groups. AVF was the most cost-effective permanent VA type in China, partly due to the inexpensive materials used compared to AVG or tcCVC.

Challenges and novel therapies for vascular access in haemodialysis

Advances in standards of care have extended the life expectancy of patients with kidney failure. However, options for chronic vascular access for haemodialysis - an essential part of kidney replacement therapy - have remained unchanged for decades. The high morbidity and mortality associated with current vascular access complications highlights an unmet clinical need for novel techniques in vascular access and is driving innovation in vascular access care. The development of devices, biological approaches and novel access techniques has led to new approaches to controlling fistula geometry and manipulating the underlying cellular and molecular pathways of the vascular endothelium, and influencing fistula maturation and formation through the use of external mechanical methods. Innovations in arteriovenous graft materials range from small modifications to the graft lumen to the creation of completely novel bioengineered grafts. Steps have even been taken to create new devices for the treatment of patients with central vein stenosis. However, these emerging therapies face difficult hurdles, and truly creative approaches to vascular access need resources that include well-designed clinical trials, frequent interaction with regulators, interventionalist education and sufficient funding. In addition, the heterogeneity of patients with kidney failure suggests it is unlikely that a 'one-size-fits-all' approach for effective vascular access will be feasible in the current environment.

Endovascular versus surgical creation of arteriovenous fistula in hemodialysis patients: Cost-effectiveness and budget impact analyses

Objectives:

The aim of the present study was to perform cost-effectiveness and budget impact analyses comparing endovascular arteriovenous fistula creation to surgical arteriovenous fistula creation in hemodialysis patients from the National Healthcare Service (NHS) perspective in Italy.

Methods:

A systematic literature review has been conducted to retrieve complications’ rates after arteriovenous fistula creation procedures. One study comparing endovascular arteriovenous fistula creation, performed with WavelinQ device, to the surgical approach through propensity score matching was preferred to single-arm investigations to execute the economic evaluations. This study was chosen to populate a Markov model to project, on a time horizon of 1 year, quality adjusted life years and costs associated with endovascular arteriovenous fistula (WavelinQ) and surgical arteriovenous fistula options for both cohorts of incident and prevalent hemodialysis patients.

Results:

For both incident and prevalent hemodialysis patients, endovascular arteriovenous fistula creation, performed with WavelinQ, was the dominant strategy over surgical arteriovenous fistula approach, showing less cost and better patients’ quality of life. Compared to the current scenario, progressively increasing utilization rates of WavelinQ over surgical arteriovenous fistula creation in the next 5 years in incident hemodialysis patients are expected to save globally 30–36 million euros to the NHS.

Conclusion:

Endovascular arteriovenous fistula creation performed with WavelinQ could be a cost-saving strategy in comparison with the surgical approach for patients in hemodialysis. Future studies comparing different devices for endovascular arteriovenous fistula creation versus the surgical option would be needed to confirm or reject the validity of this preliminary evaluation. In the meantime, decision-makers can use these results to take decisions on the diffusion of endovascular procedures in Italy.

Dialysis Access: At the Intersection of Policy, Innovation, and Clinical Care

The Advancing American Kidney Health executive order aims to reduce the incidence of end-stage kidney disease, promote home dialysis therapies, increase the number of kidney transplants, and encourage innovation in new technologies, evidence-based practice, and early detection of kidney disease. Improvements in dialysis access care are essential to the success and expansion of this program, and to being able to provide high-quality, cost-efficient care to this patient population. Specifically, the need for expanded access to home dialysis will require surgeons and interventionalists to become proficient and trained in peritoneal dialysis catheter placement and for the referral process to be streamlined to accommodate the increased interest in this modality. In addition, new technologies, namely percutaneous fistula creation, bioengineered vessels, and a variety of interventions to reduce arteriovenous stenosis, will hopefully allow for timely and durable vascular access options that will support implementation of the executive order.

Recent Advances in Arteriovenous Access Creation for Hemodialysis: New Horizons in Dialysis Vascular Access

Recent advances in technology show promise in providing greater vascular access options for hemodialysis patients. This review discusses novel methods for creating an anastomosis for arteriovenous (AV) fistulas and new materials for prosthetic AV grafts. Two technologies for endovascular arteriovenous fistula creation, the Ellipsys and WavelinQ endovascular systems, are discussed. When an AV fistula is not possible, an AV graft or devices to augment the AV fistula may be appropriate. New materials that have been developed that show promise as an alternative to the expanded polytetrafluoroethylene graft are discussed. Such potential conduits include bioengineered vessels and both allogenic or xenogenic biologic grafts. Devices designed to optimize blood flow to reduce maturation failure and improve AV fistula outcomes are explored.

Considerations in Access Cannulation: Traditional and Evolving Approaches

Needle cannulation of hemodialysis access is the soft underbelly of hemodialysis access care that has remained unchanged for a long time. Cannulation error results in complications such as infiltration, hematoma, subsequent revision procedures, and potential loss of hard-earned access. The "best" cannulation method is contingent upon access type and characteristics along with local expertise. The rope ladder technique of cannulation, characterized by successive rotation of puncture sites with each hemodialysis session, permits sufficient time for healing of prior cannulation sites, and reduction in complications such as bleeding, infection, and aneurysm development. A steeper needle angle, higher blood flow rates, and deep needle tip can lead to wall stress on the posterior wall and up to 10 cm from the needle cannulation site. Plastic cannulas provide a viable alternative to metallic needles; they have lower complications and a favorable cost-benefit ratio. There is lack of evidence to support an optimal arterial needle direction configuration. Needle injury may promote intimal thickening, but its effect on access outcomes is currently unknown. Percutaneous creation of arteriovenous fistula presents new challenges in dialysis access cannulation. Point-of-care ultrasound-guided cannulation will likely lead to a paradigm shift in access cannulation. Novel care delivery using cannulation stations is a promising development.

WavelinQ created arteriovenous fistulas versus surgical radiocephalic arteriovenous fistulas? A single-centre observational study

Purpose:

Devices to permit percutaneous endovascular arteriovenous fistula formation have recently been introduced into clinical practice with promising initial evidence. As guidelines support a distal fistula first policy, the question of whether an endovascular arteriovenous fistula should be performed as an initial option is introduced. The aims of this study were to compare a matched cohort of endovascular arteriovenous fistula with surgical radiocephalic arteriovenous fistulas.

Materials and methods:

Using data from a prospectively collected database over a 3-year period, a matched comparative analysis was performed.

Results:

WavelinQ arteriovenous fistulas (group W, n = 30) were compared with radiocephalic arteriovenous fistulas (group RC; n = 40). Procedural success was high with 96.7% for group W and 92.6% for group RC. Primary patency at 6 and 12 months was greater in group W (65.5% 6mo and 56.5% 12mo) compared to group RC (53.4% 6mo and 44% 12mo) ( p = 0.69 and 0.63). Mean primary patency was significantly lower for RC (235 ± 210 days) vs W (362 ± 240 days) ( p < 0.05). Secondary patency for group W was 75.8% and 69.5% at 6 and 12 months, respectively. Secondary patency for RC was lower at 66.7% and 57.6% at 6 and 12 months, respectively.

Conclusion:

Outcomes of WavelinQ arteriovenous fistulas in this series are similar to published results. When compared to a contemporaneously created group of surgical fistulas, WavelinQ demonstrated superior outcomes. These data would support that WavelinQ endovascular arteriovenous fistulas may be considered as a first option in the access pathway particularly if vessels at the wrist are absent or less than ideal.