Facilitated coronary anastomosis using a nitinol U-CLIP device: Bovine model

Objective: The coronary anastomosis is the most difficult part of the coron ary bypass procedure, particularly when using a minimally invasive techniqu e. Methods to facilitate coronary anastomosis will make the minimally invas ive approach to coronary bypass feasible, We sought preclinical validation and testing of the design and efficacy of a self-closing penetrating clip t hat can be used to facilitate the creation of graft-to-coronary end-to-side anastomosis. Methods: The nitinol U-Clip device (Coalescent Surgical, Inc, Sunnyvale, Ca lif) was used in 13 consecutive calves (63-118 kg). In each animal, the dev ice was (li used to create an anastomosis of the right internal thoracic ar tery to a coronary artery with the heart beating and (2) compared to polypr opylene suture when used to repair two carotid arteriotomies. Intraoperativ e, 1-week, 8-week, and 26-week postoperative angiograms and detailed histop athologic examinations were used to evaluate anastomotic patency and healin g characteristics. Results: The nitinol U-Clip device successfully created right internal thor acic artery-coronary artery anastomoses and repaired carotid arteriotomy si tes in 13 consecutive calves. The clip was precisely placed by means of the integrated suture and needle in a fashion similar to that used for convent ional suture. The clip met design specifications by reliable release and au tomatic closure, thereby eliminating knot tying and assisted suture managem ent. At the time of harvest, angiography showed widely patent coronary anas tomoses (FitzGibbon grade A criteria, n = 13) and carotid arteriotomy repai r sites (n = 13). Histopathologic evaluation confirmed normal healing with smooth circumferential neointimal resurfacing at the anastomotic and repair sites. Conclusions: The nitinol U-Clip design and function was validated in the fo rmation of bovine coronary anastomoses on the beating bovine heart with exc ellent graft patency and healing characteristics. The nitinol U-Clip device tests favorably when compared with conventional sutures in carotid artery repair.