Interrupted coalescent nitinol clip versus continuous suture coronary anastomosis: a comparative endothelial function study.

BACKGROUND A new penetrating stapled anastomotic system using nitinol microclips (Coalescent Surgical U-Clip) has been developed to facilitate the construction of compliant interrupted sutures for minimally invasive and robotic surgery as well as for conventional procedures. The purpose of this study was to determine the effect of nitinol U-Clips used for coronary anastomosis in the development of endothelial dysfunction, compared with conventional running sutures. METHODS In a porcine model, both internal thoracic arteries were harvested, and the heart was removed. In a Krebs solution, 2 anastomoses were realized ex vivo between internal thoracic arteries and the left anterior descending artery. One was carried out with 12 Coalescent microclips, and the other used conventional running 7-0 polypropylene suture material (Prolene). Coronary rings on the anastomotic sites were then placed in organ chambers filled with oxygenated Krebs solution. Vascular reactivity studies were performed in standard organ chamber experiments. After the contraction of the coronary arteries in response to prostaglandin F2alpha, the endothelium-dependent relaxation response to bradykinin was studied. The other coronary arteries served as controls. RESULTS There was no statistically significant difference among the groups (P >.05) in the amplitude of the contraction response to KCl and prostaglandin F2alpha. There were no statistically significant differences in endothelium-dependent relaxation response to bradykinin between the nitinol microclip group and controls, between the suture group and controls, and between the nitinol microclip and suture groups. CONCLUSIONS Coalescent nitinol U-Clips used as anastomotic devices do not induce an endothelial dysfunction and allow a compliant anastomosis under satisfactory conditions.