Preservation of endothelial integrity and function in experimental vascular anastomosis with non-penetrating clips

Background: Vascular repair with sutures is associated with disruption of t he endothelial lining and subsequent thrombus formation on the intraluminal lesions. This experimental study was designed to determine whether the use of non-penetrating clips improved endothelial preservation. Methods: In ten female pigs, 25-mm arteriotomies were made in both carotid arteries. The arteriotomies were repaired with jugular vein patches. On the left side, the repair was done with 1.4-mm titanium clips, and on the righ t side with two running 6/0 polypropylene sutures. Next, the aorta was divi ded and subsequently repaired with 2-mm clips in five of these pigs, and wi th two running 5/0 polypropylene sutures in the remaining five pigs. Endoth elial function was studied at the anastomotic site in the carotid arteries by determination of endothelium-dependent and -independent relaxatory respo nses. Morphometric examination of the carotid arteries and inspection of th e aortic endothelium. were performed by means of scanning electron microsco py. Results: Maximal endothelium-dependent relaxation to adenosine 5'-diphospha te was less in sutured than in clipped carotid arteries (P < 0.05), while t here was no difference in maximal endothelium-independent relaxation to sod ium nitrite. This result in clipped carotid arteries was not accompanied by less intimal hyperplasia. Screening of the aortic anastomotic line showed better preservation of endothelial architecture after clip anastomosis. Mea n cross-clamp time for carotid patch repair was significantly less when usi ng clips than with sutures. Conclusion: The use of non-penetrating clips for vascular anastomoses prese rved endothelial function and structural integrity better than running sutu res, although the degree of intimal hyperplasia was similar.