Prospective, Multicenter Clinical Study of the Covera Vascular Covered Stent in the Treatment of Stenosis at the Graft-Vein Anastomosis of Dysfunctional Hemodialysis Access Grafts.

PURPOSE: To study the use of the self-expanding Covera covered stent for the treatment of stenotic lesions at the venous anastomosis of hemodialysis arteriovenous grafts (AVGs). MATERIALS AND METHODS: A total of 110 patients with AVG venous anastomotic stenosis of ≥50% and access dysfunction were treated at 14 centers in the United States using percutaneous transluminal angioplasty followed by covered stent placement. The primary end points were 30-day safety and 6-month target lesion primary patency (TLPP). The secondary measures included access circuit primary patency, circuit cumulative patency, and the number of reinterventions through 24 months. RESULTS: Freedom from a primary safety event at 30 days was 96.4% while the 6-month TLPP rate was 70.3%. Seventy-five patients completed 24-month follow-up (68.2%). The TLPP rates were 54.2% at 365 days and 36.9% at 730 days while the access circuit primary patency rates were 16.7% at 365 days and 7.8% at 730 days (Kaplan-Meier analysis). The access circuit cumulative patency rates were 85.4% at 12 months and 73.6% at 24 months. The number of reinterventions to maintain the patency of the access circuit was 3.6 ± 3.1 at 24 months (1.6 ± 1.9 at the target lesion). CONCLUSIONS: Use of the Covera covered stent for hemodialysis graft-vein anastomotic stenosis provided a safe treatment option with a TLPP rate of 70.3% at 6 months and TLPP and cumulative access circuit patency rates of 36.9% and 73.6% at 2 years.

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.

The Pivotal Multicenter Trial of Ultrasound-Guided Percutaneous Arteriovenous Fistula Creation for Hemodialysis Access.

PURPOSE: To evaluate safety and efficacy of arteriovenous fistulas (AVFs) created with a thermal resistance anastomosis device. MATERIALS AND METHODS: A prospective single-arm trial at 5 sites enrolled 107 patients. Patients underwent ultrasound (US)-guided anastomosis creation between the proximal radial artery and perforating vein with the Ellipsys Vascular Access System (Avenu Medical, Inc, San Juan Capistrano, California) followed by separate maturation procedures. Primary endpoints were brachial artery flow volume ≥ 500 mL/min and target vein diameter ≥ 4 mm in > 49% of patients and absence of device-related complications at 90 days. RESULTS: AVFs with fused anastomoses were created in 95% (102/107) of patients. Maturation procedures included anastomotic balloon dilation in 72% (77/107), brachial vein embolization in 32% (34/107), cubital vein ligation in 31% (33/107), and surgical transposition in 26% (28/107) of patients. Primary flow and diameter endpoints were achieved in 86.0% (92/107) of patients, exceeding performance goal of 49% (P < .0001). No major adverse events were attributed to the device. Cumulative patency was 91.6%, 89.3%, and 86.7% at 90 days, 180 days, and 360 days. Target dialysis veins were cephalic, basilic, and brachial veins in 74% (73/99), 24% (24/99), and 2% (2/99) of patients. Two-needle dialysis was achieved in 88% (71/81) of patients on hemodialysis at a mean 114.3 days ± 66.2. Functional patency was 98.4%, 98.4%, and 92.3% at 90 days, 180 days, and 360 days. CONCLUSIONS: The Ellipsys® Vascular Access System met primary safety and efficacy endpoint goals in the US pivotal trial.