Longitudinal micro-incision creation prior to balloon angioplasty for treatment of arteriovenous access dysfunction in a real-world patient population: 6-month cohort analysis.

INTRODUCTION: Routine hemodialysis depends on well-functioning vascular access. In the event of vascular access dysfunction, percutaneous transluminal balloon angioplasty (PTA) is conducted to restore patency. Although an angioplasty procedure can provide an excellent immediate result by opening the access to allow dialysis to continue, the long-term patency rates are less than satisfactory. The goal of this study was to assess the outcomes of patients who underwent a novel vessel preparation via longitudinal, controlled-depth micro-incisions prior to PTA. METHODS: This multicenter, prospective, observational registry enrolled hemodialysis patients scheduled to undergo PTA of their arteriovenous fistula or graft due to clinical or hemodynamic abnormalities. A primary endpoint was anatomic success, defined as angiographic confirmation of <30% residual stenosis post-procedure without an adverse event. Additional assessments included device technical success, clinical success, freedom from target lesion revascularization, target lesion primary patency, and circuit primary patency at 6 months. FINDINGS: A total of 148 lesions were treated with the FLEX Vessel Prep™ System (FLEX VP) prior to PTA in 114 subjects at eight clinical sites. Target lesions were 21 ± 25 mm in length with mean pre-procedure stenosis of 75.2% ± 4.7%. Five procedural complications were recorded without serious adverse events. Two subjects did not complete the follow-up evaluation. Target lesion primary patency across all subjects at 6-months was 62.2% with mean freedom from target lesion revascularization of 202.7 days. Target lesion primary patency and freedom from target lesion revascularization for AVF cases (n = 72) were 67.5% and 212.9 days, respectively. Target lesion primary patency and freedom from target lesion revascularization for AVGs (n = 42) were 52.4% and 183.3 days, respectively. In cases treating AVF cephalic arch stenosis (n = 25), 6-month target lesion primary patency was 70.6% and freedom from target lesion revascularization was 213.4 days. DISCUSSION: This FLEX-AV registry demonstrates safety and effectiveness, notably in the cephalic arch and AVGs, when FLEX VP is used prior to PTA for treatment of vascular access dysfunction in a population of end-stage renal disease subjects.

Real-World Usage of the WavelinQ EndoAVF System.

BACKGROUND: Dependent on existing deep to superficial perforating venous branches, the WavelinQ EndoAVF System is a novel technique used to create an arteriovenous fistula (AVF) between ulnar or radial veins and concomitant arteries for dialysis access. We sought to examine a single center's success rates and short-term follow-up using this device. METHODS: All consecutive patients undergoing placement of a WavelinQ AVF from October 2018 to July 2019 were included. Preoperative/intraoperative variables including demographics, preoperative/postoperative duplex ultrasonography, success rate of procedure, and subsequent endovascular/surgical procedures were obtained. Descriptive statistics and comparison of groups requiring subsequent intervention were performed. RESULTS: Thirty-five patients underwent placement of the WavelinQ AVF, with 32 (91%) patients having at least one documented follow-up. These patients were predominantly male (23/32, 72%) with an average age of 60.2 and 23 of 32 (72%) patients were on dialysis. Initial fistula creation success rate was 100%. Average procedural length was 120 min, fluoroscopy time 9.6 min, and contrast usage 52.2 mL. Eight of 32 (25%) patients had perioperative complications (3 hematomas, 3 contrast extravasations, 1 resolved vessel spasm all resolving spontaneously, and 1 pseudoaneurysm requiring surgical repair). Thirteen of 32 (41%) patients underwent subsequent endovascular interventions to assist with maturation [9/32 (28%) branch coiling, 5/32 (16%) angioplasty/stenting, and 3/32 (9%) access thrombectomy] and 4 of 32 (13%) patients required subsequent surgical interventions (1 pseudoaneurysm repair, 1 revision of fistula, and 2 definitive AVF creation in thrombosed grafts). The majority of accesses (30/32, 94%) were ulnar-ulnar fistulas and overall patency at average follow-up of 73 days was 88% (28/32) with average brachial artery inflow volume of 1,078 cc/min and average cephalic vein (18/32) outflow volume of 447 cc/min. Eleven of 23 (48%) patients on dialysis were successfully using the EndoAVF at follow-up. CONCLUSIONS: The WavelinQ AVF system has a high initial procedural success rate, although a significant portion of patients require subsequent endovascular procedures to aid in maturation. Further work on determining factors predictive of need for reintervention is necessary.

Patient selection, education, and cannulation of percutaneous arteriovenous fistulae: An ASDIN White Paper.

End-stage kidney disease patients who are candidates for surgical arteriovenous fistula creation commonly experience obstacles to a functional surgical arteriovenous fistula, including protracted wait time for creation, poor maturation, and surgical arteriovenous fistula dysfunction that can result in significant patient morbidity. The recent approval of two endovascular devices designed to create a percutaneous arteriovenous fistula enables arteriovenous fistula creation to be placed in the hands of interventionalists, thereby increasing the number of arteriovenous fistula providers, reducing wait times, and allowing the patient to avoid surgery. Moreover, current studies demonstrate that patients with percutaneous arteriovenous fistula experience improved time to arteriovenous fistula maturation. Yet, in order to realize the potential advantages of percutaneous arteriovenous fistula creation within our hemodialysis patient population, it is critical to select appropriate patients, ensure adequate patient and dialysis unit education, and provide sufficient instruction in percutaneous arteriovenous fistula cannulation and monitoring. In this White Paper by the American Society of Diagnostic and Interventional Nephrology, experts in interventional nephrology, surgery, and interventional radiology convened and provide recommendations on the aforementioned elements that are fundamental to a functional percutaneous arteriovenous fistula.

Stent-Graft Length Is Associated with Decreased Patency in Treatment of Central Venous Stenosis in Hemodialysis Patients.

BACKGROUND: Central venous occlusion may occur in hemodialysis patients, resulting in arm or facial swelling and failure of dialysis access. Endovascular management with balloon angioplasty or stenting has been described, but there are minimal data on the use of covered stents in this pathology. We sought to review a single institution's experience with the use of covered stents for central venous occlusive disease in hemodialysis patients. METHODS: A retrospective review of all patients undergoing placement of covered stents between April 2014 and December 2016 for central venous occlusive disease to preserve a failing dialysis access was performed. Patients' records were reviewed to identify demographics, medical comorbidities, operative variables, primary patency rates, and secondary interventions. RESULTS: A total of 29 patients were included in the analysis. Viabahn (W.L. Gore and Associates, Flagstaff, AZ) stent grafts were exclusively used in all patients. Technical success rate was 100%. The patients were predominantly female (65.5%), with a mean age of 67.9 ± 12.1 and medical comorbidities of hypertension (86%), diabetes (76%), and tobacco use (7%). The majority (86%) had prior angioplasty and 17 of 29 (59%) patients had previous central venous catheters. The right brachiocephalic vein was the most commonly stented vessel (28%). The median stent length and diameter used were 50 millimeters (range 25-100 millimeters) and 13 millimeters (range: 9-13 millimeters), respectively. The majority of patients (83%) received a single stent, with only 2 patients requiring more than one. Median follow-up was 24 months (range: 6-41 months). Four of 29 (13.8%) patients developed symptomatic stent restenosis requiring secondary intervention, all of which occurred in patients with primary stenosis between 50% and 75%. When compared to the patients without restenosis, longer stents were found to be significantly associated with restenosis (62.5 centimeters, interquartile range [IQR]: 0] vs. 50 centimeter, IQR: 0, P = 0.002). Primary patency rates were 92.9%, 91.7%, and 80.0% at 6, 12, and 24 months respectively. Secondary patency rates were 96.4%, 95.8%, and 93.3% at 6 months, 12 months, and 24 months, respectively. The overall primary patency rate was estimated at 86.2% using Kaplan-Meier analysis at 30.5 months (95% confidence interval: 26.5-34.5 months). CONCLUSIONS: Covered stent grafts have reasonable primary patency and excellent secondary patency when used for central venous stenosis in dialysis patients. Stent-graft length is associated with poorer long-term patency rates.

Peritoneal dialysis catheter insertion by interventional nephrologists.

Peritoneal dialysis (PD) catheter placement is performed by surgeons, interventional radiologists, and interventional nephrologists. Catheter insertion is accomplished through various methods including open surgical technique and laparoscopic, peritoneoscopic, and fluoroscopic guidance. Complication rates and catheter survival can vary based on the insertion technique used. Recently, nephrologists have made significant advances in the area of peritoneal dialysis catheter design and placement. Current data suggest that nephrologists are increasingly placing PD catheters using peritoneoscopic and fluoroscopic technique. This review focuses on peritoneoscopic and fluoroscopic insertion and highlights the advantages of catheter insertion by nephrologists.