A Review of the Current Status of Percutaneous Endovascular Arteriovenous Fistula Creation for Haemodialysis Access

Two-Year Cumulative and Functional Patency after Creation of Endovascular Arteriovenous Hemodialysis Fistulae

PURPOSE

To assess 2-year cumulative and functional patency of endovascular arteriovenous fistulae (endoAVF) created with the WavelinQ device.

MATERIALS AND METHODS

Patients who had fistulae created at a single center from December 2019 to December 2020 were included in this retrospective study. Forty-three patients underwent endoAVF creation (22 females, 21 males). Data collected included patient demographics, location of fistula creation, interventions performed, and brachial artery flow before and after creation. Two-year cumulative and functional patency rates were assessed with Kaplan-Meier method, and variables that affected patency and maturation were examined using Cox proportional hazards model.

RESULTS

Technical success was 95% (41/43), and in 4 patients, the fistula did not mature for dialysis use (9.7%). For the remaining 37 patients with endoAVF maturation, 25 had ulnar-ulnar fistulae, 10 had radial-radial fistulae, and 2 had interosseous artery-vein fistulae. Mean maturity time was 73 days, and brachial artery flow of >886 mL/min was predictive of maturation. Mean tunneled dialysis catheter removal time was 133 days. Number of interventions per patient-year was 0.38, where 8 were maturation procedures (5 vein elevations/transpositions and 3 coil embolizations) and 21 were maintenance angioplasties. Two-year cumulative/secondary and functional patency rates were 89.4% and 92.1%, respectively, with a mean follow-up of 665.7 days. Examined variables did not impact cumulative or functional patency. One adverse event was migration of coil to the heart, which was successfully retrieved at time of procedure.

CONCLUSIONS

Two-year patency of 89.4% and functional patency of 92.1% were observed after endoAVF creation with WavelinQ device.

Vascular access surgery training in the United Kingdom is currently perceived (by trainees) to be inadequate

INTRODUCTION

Vascular access surgery (VAS) involves the creation and maintenance of arteriovenous access to facilitate haemodialysis. The prevalence of haemodialysis is rising despite increases in kidney transplants on a yearly basis. There is currently only one access surgery fellowship accredited by the Royal College of Surgeons of England. We aimed to establish the experience and perceived competence in access surgery of senior vascular surgery trainees.

METHODS

A short questionnaire (SurveyMonkey) was used to survey all senior (ST6-ST8) vascular surgery trainees in Health Education England (HEE) vascular surgery training programmes. The short survey asked trainees to report their: (1) training grade; (2) training deanery; (3) experience of access surgery; and (4) whether senior trainees thought they would be able to independently undertake primary access surgery post-completion of training (post Certificate of Completion of Training). The survey was circulated via HEE deaneries and the vascular surgery trainees' society: the Rouleaux Club.

RESULTS

Twenty-eight senior (ST6-ST8) vascular surgery trainees responded to the survey: 29.6% were ST6 level, 33.3% were ST7 and 37.1% were ST8. Deanery respondence was evenly spread, although London was overrepresented (37.1%). In total, 28.6% had been involved in fewer than 10 cases, 35.7% in 10-25 cases, and 35.7% in more than 25 cases. Almost 54% of senior vascular surgery trainees believed they would not be able to undertake independent access surgery once they had completed training.

CONCLUSIONS

Competence in access surgery is an increasing requirement of a consultant vascular surgeon. More formalised training is required to adequately train the next generation of vascular surgeons.

Vascular access surgery training in the United Kingdom is currently perceived (by trainees) to be inadequate

INTRODUCTION

Vascular access surgery (VAS) involves the creation and maintenance of arteriovenous access to facilitate haemodialysis. The prevalence of haemodialysis is rising despite increases in kidney transplants on a yearly basis. There is currently only one access surgery fellowship accredited by the Royal College of Surgeons of England. We aimed to establish the experience and perceived competence in access surgery of senior vascular surgery trainees.

METHODS

A short questionnaire (SurveyMonkey) was used to survey all senior (ST6-ST8) vascular surgery trainees in Health Education England (HEE) vascular surgery training programmes. The short survey asked trainees to report their: (1) training grade; (2) training deanery; (3) experience of access surgery; and (4) whether senior trainees thought they would be able to independently undertake primary access surgery post-completion of training (post Certificate of Completion of Training). The survey was circulated via HEE deaneries and the vascular surgery trainees' society: the Rouleaux Club.

RESULTS

Twenty-eight senior (ST6-ST8) vascular surgery trainees responded to the survey: 29.6% were ST6 level, 33.3% were ST7 and 37.1% were ST8. Deanery respondence was evenly spread, although London was overrepresented (37.1%). In total, 28.6% had been involved in fewer than 10 cases, 35.7% in 10-25 cases, and 35.7% in more than 25 cases. Almost 54% of senior vascular surgery trainees believed they would not be able to undertake independent access surgery once they had completed training.

CONCLUSIONS

Competence in access surgery is an increasing requirement of a consultant vascular surgeon. More formalised training is required to adequately train the next generation of vascular surgeons.

Arterial revascularization in patients with hand pain dialyzing with upper arm Arteriovenous (AV) fistulas: A single center experience

BACKGROUND

Distal hand ischemia syndrome (DHIS) is a well reported adverse outcome in patients with upper arm AV access. 25%-40% of these patients have been reported to be due to primary arterial disease complicated with significant arterial calcification. The effectiveness of revascularization of the distal arterial circulation on symptom resolution has not been reported yet.

METHODS

Retrospective single center analysis of patients evaluated for hand/forearm pain in patients with upper arm AV access who had arterial revascularization between 01/2016 and 12/2020 were included for the analysis. Fifty-one patients met inclusion criteria. Stenotic lesions greater than 70% in the subclavian, axillary, brachial, radial, or ulnar artery were treated with balloon angioplasty. Institutional approval was obtained to review charts.

OUTCOMES

Successful revascularization, improvement in pain in 48 h, 1 month, and 3 months.

RESULTS

Seventy six percent of patients had an upper arm Arteriovenous Fistula (AVF) and 24% patients had an upper arm Arteriovenous Graft (AVG). Mean access flow was 1210 (556) ml/min. 55% of patients had radial or ulnar arterial stenosis, 45% had brachial/axillary or subclavian artery stenosis. 45% patients had lesions in both radial and ulnar arteries, 88% of patients were successfully revascularized. 76% (18) of patients had improvement in symptoms within 48 h and 68% remained symptom free in 3 months. Mean DHIS stage was 3.1 before intervention and improved to 1.1 post intervention (p < 0.001). Patient satisfaction with their AV access improved from 34% to 72% (p < 0.01). Multiple regression analysis did not reveal statistically significant correlations between time on dialysis vintage and other chronic medical conditions on post procedure symptom improvement.

CONCLUSIONS

DHIS with occlusive arterial disease can be successfully revascularized to improve symptoms. Complete evaluation of the inflow arterial segment and optimal endovascular revascularization could decrease the need for access revision procedures or access abandonment.

Performance Characteristics of Candidate Criteria for Hemodialysis Arteriovenous Fistula Maturation

BACKGROUND

Twenty to 60% of newly created hemodialysis arteriovenous fistulas do not mature adequately for use. One barrier to developing interventions to improve fistula outcomes is a lack of standardized criteria for maturation.

METHODS

Using data from the multicenter, prospective Hemodialysis Fistula Maturation (HFM) Study, we determined sensitivities, specificities, and positive and negative predictive values of multiple candidate maturation criteria using the HFM Study maturation criteria as the reference. We also compared, across the maturation criteria, relationships between maturation and fistula survival using Cox proportional hazards models.

RESULTS

We included 535 of the 602 HFM Study participants. The median (interquartile range) age was 57 (47-65) years, 70% were men, and 45% were Black participants. Depending on the criterion and time frame for ascertainment (3, 4, 5, 6, or 9 months), sensitivities ranged from 57% to 100%, specificities ranged from 85% to 100%, positive predictive values ranged from 88% to 100%, and negative predictive values ranged from 65% to 100%. For all criteria, areas under the curve for the 6-month (0.90-0.97 for unassisted maturation and 0.89-0.95 for overall maturation) and 9-month time frames were similar. Attainment of unassisted maturation was associated with lower risks of fistula abandonment, with hazard ratios ranging from 0.10 to 0.40 depending on the criterion and time frame. Eliminating dialysis adequacy indicators, or simplifying the criteria in other ways, had little effect on performance characteristics.

CONCLUSIONS

High performance characteristics are maintained with maturation criteria that are simpler and less burdensome to ascertain than the HFM Study outcome measure.

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.

Magnetic Resonance Angiography of the Arteries of the Upper and Lower Extremities

Magnetic resonance angiography (MRA) is a powerful tool for assessing upper and lower extremity artery pathologies. In addition to the classic advantages of MRA, such as the absence of radiation and iodinated contrast exposure, it can provide high temporal resolution/dynamic images of the arteries with high soft tissue contrast. Although it has a relatively lower spatial resolution than computed tomography angiography, MRA does not cause blooming artifacts in heavily calcified vessels, which is crucial in small vessel assessment. Although contrast-enhanced MRA is the most preferred technique to assess extremity vascular pathologies, recent advances in non-contrast MRA protocols provide an alternative imaging technique for patients with chronic kidney disease.

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.

Hemodialysis Arteriovenous Fistula Dysfunction: Retrospective Comparison of Post-thrombotic Percutaneous Endovascular Interventions with Pre-emptive Angioplasty

OBJECTIVES

We aimed to compare the clinical outcomes of pre-emptive angioplasty versus post-thrombotic percutaneous endovascular restoration of dysfunctional arteriovenous fistula (AVF).

METHODS

This retrospective study reviewed data from 80 patients who underwent 114 endovascular interventions for a malfunctioning AVF from July 2016 to August 2019. Stenotic AVFs were treated with pre-emptive angioplasty. Thrombosed AVFs were treated with percutaneous pharmacomechanical fibrinolysis with urokinase used only during the operation or continuously infused. The differences in patency rates were evaluated using Kaplan-Meier method. In addition, univariate and multivariate regression Cox models were used to determine influential factors on the post-intervention primary patency.

RESULTS

Post-thrombotic interventions and pre-emptive angioplasty yielded statistically similar rates in clinical success (100% vs 100%), anatomic success (94% vs 89%; p = .52), complication (4% vs 11%; p = .29), as well as postintervention primary, assisted primary and secondary patency (p = .80; .57; .57). The use of pre-emptive angioplasty was associated with reduced total cost (¥25108 vs ¥30833, p< .001). The patients who used urokinase only during the operation prolonged both the primary and assisted primary patency (p = .02; .002), while those with continuous infusion of urokinase had worst patency rates and high costs (¥39275 vs ¥25108 vs ¥27140, p< .001). Compared with the other locations, dysfunction in the anastomotic or juxta-anastomotic segment (HR = .41, p = .001) was associated with prolonged postintervention primary patency.

CONCLUSIONS

No clinical outcome differences was found between the post-thrombotic percutaneous endovascular interventions and pre-emptive angioplasty. However, pre-emptive angioplasty decreased access expenditure.

Devices and Techniques for Percutaneous Creation of Dialysis Arteriovenous Fistulas

Dialysis treatment for chronic kidney disease was first developed by Dr. Willem Kolff in 1943, and its availability began to grow in 1962 after which it has become a mainstay treatment for patients with chronic kidney disease. It is estimated that, in 2021, 15% of adults in the United States (∼37 million people) have chronic kidney disease, of which 661,000 individuals have renal failure, and 468,000 individuals require dialysis. There have been several advancements in dialysis treatment since its advent, most notably the creation of arteriovenous fistulas (AVFs) for venous access in 1966. In recent years, the U.S. Food and Drug Administration approved two new devices for AVF creation using a percutaneous approach. These are the WavelinQ (Becton Dickinson, New Jersey) and the Ellipsys (Avenu Medical, California) endovascular AVF (endoAVF) devices that use radiofrequency and thermal technologies, respectively, to create the AVF. Since the introduction of these technologies, several studies have shown that they are safe and effective, with favorable durability and low rate of serious adverse events. In this article, we will discuss these two devices and the techniques used for percutaneous creation of dialysis AVF as an alternative to traditional open surgical techniques.

Clinical and ultrasound evaluation for hemodialysis access creation

Chronic kidney disease (CKD) is an emerging global burden with an increasing number of patient's requiring renal replacement therapy (RRT), with hemodialysis being the most prevalent dialysis modality. A functioning vascular access remains the main constrain for an adequate treatment. Clinical and, in some patients, ultrasound evaluation are fundamental for better access planning. Access planning is dependent not only on patient clinical characteristics and preference but also in vascular patrimony. As such, ultrasound evaluation aids in characterizing patient arterial and venous upper arm anatomy and provides information for which access would better suit each patient. Doctors dealing with CKD patients should be familiar with the role of ultrasound and Doppler use in access planning.

Issues in Teaching Vascular Anatomy: Thoughts and Suggestions from the Clinician's Point of View

The role of anatomy in modern curricula is under reform due to competency of other rapidly evolving subjects and the rapid evolution of several practical aspects and applications dictating modernization of teaching methods as well as of teaching demands. Moreover, modern practice of medicine has put the arterial and vascular system in the center of numerous minimally invasive techniques. Therefore, regardless of their specialty, most doctors should have a very clear and precise knowledge of the vascular anatomy and the basic access techniques from the early years. This viewpoint commentary reflects the experience of the two authors in applying the principles and content of surgical vascular anatomy in undergraduate anatomy teaching and discusses the rationale of this. Moreover, it is suggested that cadaveric dissections should be modified with emphasis on standard surgical vascular exposures and the multidisciplinary teaching of vascular anatomy as a means not only to gain optimal long-term knowledge retention, but also to emphasize through realistic examples on the practical clinical value of vascular anatomy.

Application Value and Relevance Analysis of the Risk Evaluation System for Arteriovenous Fistula Puncture in Thrombosis after Puncture

Objective

To analyze the application value and relevance of risk evaluation system for arteriovenous fistula (AVF) puncture in thrombosis after puncture.

Methods

The clinical data of 180 patients treated with hemodialysis in the hemodialysis center of our hospital from November 2017 to November 2019 were retrospectively analyzed. After puncture, all patients received the digital subtraction angiography (DSA) examination, and based on whether they had AVF thrombosis, they were divided into the nonthrombosis group (n = 102) and thrombosis group (n = 78), and then, according to the parity of their admission numbers, the patients in the thrombosis group were subdivided into the study group (n = 39) and the reference group (n = 39), so as to analyze the risk factors of thrombosis after AVF puncture and the application value of the risk evaluation system for AVF puncture in preventing and treating thrombosis.

Results

Compared with the reference group after intervention, the study group had significantly higher mean internal fistula blood flow volume (P < 0.001) and significantly lower total incidence rate of vascular complications in fistulas (P < 0.05); according to the multifactor binary logistic regression analysis, it was found that diabetes, systolic blood pressure reduction, hemoglobin, low-density lipoprotein cholesterol (LDL-C), ultrafiltration rate, and elevation of blood phosphorus and platelet levels were the risk factors of thrombosis after AVF puncture in hemodialysis patients.

Conclusion

When risk factors of thrombosis are found in patients treated with hemodialysis, timely detection and intervention shall be applied in the early stage. Adopting the AVF puncture risk evaluation system has an extremely high application value in the clinic and is of important meaning in prolonging the service life of fistulas.

Early cannulation versus standard arteriovenous grafts in hemodialysis patients: a randomized clinical study

OBJECTIVE

Arteriovenous grafts (AVGs) are frequently needed in hemodialysis (HD) patients with unsuitable superficial veins. First cannulation of standard arteriovenous grafts (sAVGs) still require about 2 weeks after implantation. Early cannulation arteriovenous grafts (eAVGs) were suggested to overcome this shortcoming. The present randomized study proposed to compare the clinical outcomes of sAVGs and eAVGs in HD patients.

METHODS

The present single-center randomized clinical study recruited 477 HD patients indicated for AVG creation. They included 236 in the sAVG group and 241 in the eAVG group. Eligible patients were simply randomized and allocated to the studied groups using 1:1 allocation ratio. Blinding was secured using the sealed envelope technique. Enrolled patients were followed up for 12 months. The primary outcome in the present study was primary, primary assisted, and secondary patency rates at 12 months. Other outcome parameters included time to first cannulation, graft complications, and mortality.

RESULTS

Comparison between the studied groups regarding the primary outcomes revealed no statistically significant differences. Primary patency rate was 65.7% and 68.0% (P = .58) at 6 months and 53.8% and 56.4% (P = .57) at 12 months in the sAVG and eAVG groups, respectively. Primary assisted patency rate was 70.8% and 69.7% (P = .8) in patients with sAVG and eAVG, whereas the reported rates at 12 months were 59.3% and 61.0% (P = .71), respectively. Secondary patency rate was 78.4% and 73.9% (P = .25) at 6 months and 67.8% and 69.7% (P = .65) at 12 months in the sAVG and eAVG groups, respectively. As expected, patients in the eAVG group experienced significantly earlier cannulation when compared with patients in the sAVG group (median, 3.0 days; range, 1.0-9.0 days vs 19.0 days; range, 15.0-22.0 days; P < .001).

CONCLUSIONS

Patients in the eAVG group have comparable outcomes to those in the sAVG group at 12 months with the added advantage of earlier time to first cannulation.

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.

A call to optimize haemodialysis vascular access care in healthcare disrupted by COVID-19 pandemic

The COVID-19 pandemic has resulted in major disruption to the delivery of both routine and urgent healthcare needs in many institutions across the globe. Vascular access (VA) for haemodalysis (HD) is considered the patient's lifeline and its maintenance is essential for the continuation of a life saving treatment. Prior to the COVID-19 pandemic, the provision of VA for dialysis was already constrained. Throughout the pandemic, inevitably, many patients with chronic kidney disease (CKD) have not received timely intervention for VA care. This could have a detrimental impact on dialysis patient outcomes in the near future and needs to be addressed urgently. Many societies have issued prioritisation to allow rationing based on clinical risk, mainly according to estimated urgency and need for treatment. The recommendations recently proposed by the European and American Vascular Societies in the COVID-19 pandemic era regarding the triage of various vascular operations into urgent, emergent and elective are debatable. VA creation and interventions maintain the lifeline of complex HD patients, and the indication for surgery and other interventions warrants patient-specific clinical judgement and pathways. Keeping the use of central venous catheters at a minimum, with the goal of creating the right access, in the right patient, at the right time, and for the right reasons, is mandatory. These strategies may require local modifications. Risk assessments may need specific "renal pathways" to be developed rather than applying standard surgical risk stratification. In conclusion, in order to recover from the second wave of COVID-19 and prepare for further phases, the provision of the best dialysis access, including peritoneal dialysis, will require working closely with the multidisciplinary team involved in the assessment, creation, cannulation, surveillance, maintenance, and salvage of definitive access.

Clinical and ultrasound evaluation for hemodialysis access creation

Chronic kidney disease (CKD) is an emerging global burden with an increasing number of patient's requiring renal replacement therapy (RRT), with hemodialysis being the most prevalent dialysis modality. A functioning vascular access remains the main constrain for an adequate treatment. Clinical and, in some patients, ultrasound evaluation are fundamental for better access planning. Access planning is dependent not only on patient clinical characteristics and preference but also in vascular patrimony. As such, ultrasound evaluation aids in characterizing patient arterial and venous upper arm anatomy and provides information for which access would better suit each patient. Doctors dealing with CKD patients should be familiar with the role of ultrasound and Doppler use in access planning.

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.

The role of surgery for assisted maturation after endovascular and percutaneous arteriovenous fistula creation

Even in the best of circumstances, a significant number of patients will require adjunctive endovascular and/or surgical revision prior to achieving functional patency after endovascular or percutaneous AVF creation, at least within the United States. This rate appears to be higher after percutaneous AVF than after endovascular AVF, although because published reports of the former are mostly derived from American experience and those of the latter derived from experience outside the United States, it is unclear whether these differences are due to the technique itself or cultural and/or anatomic differences in dialysis access practices and patient populations. If arterial inflow is poor, this should be corrected first. When flow is adequate (perhaps 900 cc/min) but no single vein is cannulatable, a dominant suitable vein can be superficialized or transposed. If no suitable vein is dominant (most accurately assessed by using an intraoperative flowmeter), the best vein can be used, with or without occlusion of the other veins or reimplantation into the brachial artery. Finally, if the original anastomosis remains the sole supply to the cannulated vein, the original fistula has achieved assisted primary maturation (and assisted primary patency continues), while if a new arteriovenous anastomosis has been constructed, the original fistula has failed. We point out that for this reason as well as to best utilize the upper arm for later access, endovascular and percutaneous AVFs should be constructed and maintained within an atmosphere where both surgeons and non-surgeons work together on the overall access plan.

Policy and Pandemic: The Changing Practice of Nephrology During the Coronavirus Disease-2019 Outbreak

The coronavirus (coronavirus disease-2019) pandemic has changed care delivery for patients with end-stage kidney disease. We explore the US healthcare system as it pertains to dialysis care, including existing policies, modifications implemented in response to the coronavirus disease-2019 crisis, and possible next steps for policy makers and nephrologists. This includes policies related to resource management, use of telemedicine, prioritization of dialysis access procedures, expansion of home dialysis modalities, administrative duties, and quality assessment. The government has already established policies that have instated some flexibilities to help providers focus their response to the crisis. However, future policy during and after the coronavirus disease-2019 pandemic can bolster our ability to optimize care for patients with end-stage kidney disease. Key themes in this perspective are the importance of policy flexibility, clear strategies for emergency preparedness, and robust health systems that maximize accessibility and patient autonomy.

Novel Approaches to Arteriovenous Access Creation, Maturation, Suitability, and Durability for Dialysis

Since the arteriovenous fistula (AVF) was first conceived over 50 years ago, the goal to create a vascular conduit with predictable and reproducible maturation and durability continues to elude caregivers. Recently, however, advances in the understanding of vascular biology and new technologies now provides us with some optimism; we are moving toward a viable solution. A quickly maturing, sustainable, and durable arteriovenous access may soon be attainable. This review will discuss these advances. There are novel approaches to AVF creation and devices to enhance maturation, advances in arteriovenous graft material(s), and devices to safely prolong the use of tunneled dialysis catheters. Although hemodialysis (HD) access remains a complex problem, these innovations may lead the way to optimizing the care and the quality of life of those patients who have no choice but to proceed with HD.

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.

Two-year cumulative patency of endovascular arteriovenous fistula

BACKGROUND AND OBJECTIVES

The recent advent of a device to create a proximal radial artery arteriovenous fistula using an endovascular approach to create the anastomosis represents a significant advance in dialysis access creation. This endovascular arteriovenous fistula offers the beneficial attributes of the proximal radial artery arteriovenous fistula while adding the advantages of avoiding a surgical procedure. The endovascular arteriovenous fistula can be created safely, functions well, has excellent patency, and has a high degree of patient satisfaction. The purpose of this study is to report the 2-year cumulative patency rate for a large multicenter cohort of endovascular arteriovenous fistula cases.

DESIGN

An endovascular arteriovenous fistula was created in 105 patients using either local or regional anesthesia and conscious sedation. Patient data were obtained from each program's electronic health record system. Data collection was truncated at 2 years postprocedure and used to calculate cumulative patency. Post-access creation patient satisfaction was assessed.

RESULTS

A physiologically mature arteriovenous fistula (blood flow ⩾500 mL/min and a target vein internal diameter ⩾4 mm) was obtained in 98%. A clinically functional arteriovenous fistula (supporting two-needle dialysis according to the patient's dialysis prescription) was demonstrated in 95%. Access failure resulting in the loss of access occurred in eight cases during the study period. The cumulative patency rate at 6, 12, 18, and 24 months was 97.1%, 93.9%, 93.9%, and 92.7%, respectively. The post-procedure patient evaluation emphasized a high level of patient satisfaction.

CONCLUSION

The proximal radial artery arteriovenous fistula created using an endovascular approach for the anastomosis is associated with excellent 2-year cumulative patency and is associated with a high level of patient satisfaction.

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.

Early experience and observations in endovascular dialysis fistula re-intervention

In recent years, new emerging technology has allowed the endovascular creation of dialysis fistulas in the proximal forearm without the need for open surgery. Two such systems currently exist, and evidence to date has demonstrated high rates of technical success in fistula creation, high rates of dialysis functionality, and low rates of re-intervention using both systems. Whilst early trial data has demonstrated lower rates of re-intervention to maintain patency compared to surgical fistulas, endovascular re-interventions are still required to maintain functionality. The endovascular fistula (endoAVF) typically exhibits a shared drainage pattern and is morphologically distinct from the surgical fistula and patterns of failure observed often differ to what has been traditionally encountered. A fresh approach and understanding is therefore required and here we share our observations and experience of endovascular re-intervention in endoAVF created with the Wavelinq system.

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.