Abstract 13903: Application of in vivo Tissue-engineered, Autologous “Biotube” Vascular Grafts, Prepared Using a Less Invasive Device, for Hemodialysis Access in a Canine Model

Abstract

Purpose: When arteriovenous (AV) fistula is not feasible for vascular access in most patients on hemodialysis, the second choice is interposition AV fistula using synthetic graft. However, the grafts pose risks such as infection and low patency. Therefore, we created in vivo tissue-engineered “Biotube” vascular grafts formed with autologous tissue, based on the tissue encapsulation phenomenon. Previously, we confirmed that vascular-like structure was reconstructed in implanted Biotubes with year-ordered patency in vivo. In this study, we evaluated whether Biotubes could replace vascular access grafts for hemodialysis in the cervical vessels of beagles. Methods and Results: The mold for Biotube preparation was assembled by inserting a silicone rod (external diameter 4 mm; length 50 mm) into an acrylate tubular cover (internal diameter 6 mm; length 50 mm with several longitudinal slits). The molds were embedded into the dorsal subcutaneous pouches of beagles (n=3) for 4 weeks, after which they were harvested by a minimally invasive technique from the same incision (width ca. 20 mm). After removing the molds, Biotubes formed by tissue migration to a silicone surface through the mold slits (internal diameter 4 mm; length 45 mm; wall thickness ca. 1 mm) were obtained. Biotubes were then bypassed between the carotid artery (side-to-end anastomosis) and jugular vein (end-to-end anastomosis) of anesthetized beagles. Following placement of Biotubes, continuous thrill was felt by palpation and ultrasound showed turbulent blood flow. After one month, angiography showed no stenosis, elongation, or hemorrhage in any Biotubes. Percutaneous puncturing with a needle, blood removal and resupply from the needle, and astirction within several minutes were feasible. Conclusions: In our beagle model, Biotubes successfully created an AV shunt that maintained steady blood flow, suggesting that Biotubes have potential clinical use in maintaining vascular access for hemodialysis.