Enabling sutureless vascular bypass grafting with the exovascular sleeve anastomosis

Purpose: We describe a technique for end-to-end sleeve anastomosis that may enable minimally invasive bypass grafting and characterize the tensile str ength, stenosis rate, durability, and healing of the anastomosis. Method: An anastomotic device assembly consisting of a cable tie-type band with mobile teeth elements is mounted on the outer surface of a polytetrafl uoroethylene graft. The graft is drawn over the artery resulting in a sleev e of vessel within the graft. As the band is tightened over an intraluminal obturator, the independently mobile anchoring teeth are driven through the graft into the artery. The tensile strength of the anastomosis was compare d with sutured anastomosis during in vitro studies using cadaveric human fe moral arteries. For in vivo studies on pigs and goats, we used a proximal e xovascular sleeve anastomosis along with a distal sutured aortic anastomosi s. Survival animals were studied by angiogram postoperatively and at the ti me of explantation. Results: In vitro studies showed no difference in maximal tensile strength between sutured and exovascular anastomoses (10.5 +/- 2.7 lb vs 10.2 +/- 3. 0 lb, P = .83). However, loss of continuous graft to artery interface occur red at lower loads in the sutured anastomoses (6.5 +/- 0.6 lb, P < .05). In total, all 24 pigs tested in nonsurvival or survival settings sustained a successful and leakproof anastomosis. Of the 13 nonsurvival cases, maximal epinephrine-induced hypertension sustained over 15 minutes (peak systolic b lood pressure > 210-250 mm Hg) was tolerated without leakage in a subgroup of five animals (100%). All 11 survival pigs had no pseudoaneurysms or sten osis relative to sutured control anastomoses at 6 week explantation (8.2 +/ - 1.25 mm vs 8.5 +/- 1.6 mm, P = .21). The three long-term survival goats h ad no pseudoaneurysm or stenosis after 40 weeks. Histologic examination con firmed healing of the aorta to graft with minimal neointimal hyperplasia. Conclusion: Exovascular sutureless anastomosis appears comparable to suture d anastomosis in stenosis rate, healing, and durability, with some advantag es in tensile strength and rapidity of application.