Biological vascular grafts for hemodialysis access

Evaluation of: Tillman BW, Yazdani SK, Neff LP et al. Bioengineered vascular access maintains structural integrity in response to arteriovenous flow and repeated needle puncture. J. Vasc. Surg. 56(3), 783-793 (2012). Alternatives to autogenous arteriovenous hemodialysis (HD) access, such as synthetic arteriovenous bypass grafts and central venous catheters, are associated with a higher rate of complications. The evaluated article assessed the repeated cannulation challenges of HD in tissue-engineered blood vessels implanted in a bovine in vivo model (n = 15). Two groups were studied. A short-term group in which the graft was explanted and histologically examined (n = 7) and a second group in which the graft was left in for 6 months or until outflow venous stenosis occurred (n = 8). Two grafts from each group occluded 1-month postoperatively. Of the 11 remaining, cannulation was well tolerated with adequate hemostasis. Histological analysis demonstrated host cell repopulation of the outer surface in the short-term group (n = 5) and stable wall geometry in the long-term group. The authors concluded that their study proves the concept of using a scaffold-based approach to tissue-engineered blood vessels for HD access.