Human tissue-engineered blood vessels for adult arterial revascularization.

There is a crucial need for alternatives to native vein or artery for vascular surgery. The clinical efficacy of synthetic, allogeneic or xenogeneic vessels has been limited by thrombosis, rejection, chronic inflammation and poor mechanical properties. Using adult human fibroblasts extracted from skin biopsies harvested from individuals with advanced cardiovascular disease, we constructed tissue-engineered blood vessels (TEBVs) that serve as arterial bypass grafts in long-term animal models. These TEBVs have mechanical properties similar to human blood vessels, without relying upon synthetic or exogenous scaffolding. The TEBVs are antithrombogenic and mechanically stable for 8 months in vivo. Histological analysis showed complete tissue integration and formation of vasa vasorum. The endothelium was confluent and positive for von Willebrand factor. A smooth muscle-specific alpha-actin-positive cell population developed within the TEBV, suggesting regeneration of a vascular media. Electron microscopy showed an endothelial basement membrane, elastogenesis and a complex collagen network. These results indicate that a completely biological and clinically relevant TEBV can be assembled exclusively from an individual's own cells.

Transition to all-autogenous hemodialysis access: the role of preoperative vein mapping.

Safe, reliable, and efficient hemodialysis access (DA) remains an unrealized ideal. Autogenous dialysis access (ADA) may improve outcome for renal failure patients. We now place ADA in 9 out of 10 new patients in an effort to maximize primary patency and minimize access-related complications. We reviewed our recent DA experience to determine whether our increased reliance on autogenous access (ADA) has improved outcomes, and to evaluate the impact of preoperative duplex venous imaging (vein mapping) on early and intermediate results. We conducted a retrospective database review of 108 consecutive patients undergoing initial permanent DA between 10/97 and 8/01. Mean follow-up was 13.1 months. Our results showed that increased ADA utilization decreases the need for secondary access procedures. The functional superiority of ADA vs. prosthetic dialysis access (PDA) in this series may be due to optimal autogenous conduit selection facilitated by preoperative vein mapping.