Vascular clips have ho significant effect on the cellular proliferation, intimal changes, or peak systolic velocity at anastomoses in rabbit vein grafts

Objective. This study compares vascular closure staples (VCSs) with convent ional sutures in the rabbit carotid vein graft model to determine whether a nastomotic technique affects cellular proliferation, blood velocity, or int imal changes when measured over a period of 3 months postoperatively, Methods. Twenty-six New Zealand White rabbits weighing 3.0-3.2 kg underwent interposition of jugular vein grafts in left carotid arteries. Half of the animals had anastomoses performed with small VCSs (n = 13) and half had an astomoses performed with 8-0 interrupted polypropylene suture. Animals were allowed to survive for 1 week (n = 4, VCS; n = 4, suture), 2 weeks (n = 4, VCS; n = 4, suture), and 3 months (n = 5, VCS; n = 5, suture). The peak sy stolic velocity (PSV) at the distal anastomosis was measured after completi on of the graft and again at sacrifice in the S-month survival groups, At s acrifice, sections were taken from the middle and distal end of the vein gr aft and the distal carotid artery, Vascular cell proliferation was measured using 5-bromo-2'-deoxyuridine labeling and intimal changes were measured u sing digitized microscopic images. Results. All 26 grafts were open at the time of sacrifice. PSV at the dista l clipped anastomosis was 40.52 cm/s (t = 0) and 34.3 cm/s (t = 3 months, P = 0.31), PSV at the distal sutured anastomosis was 38.30 cm/s (t = 0) and 39.23 cm/s (t = 3 months, P = 0.82), There was no difference between the tw o techniques at either t = 0 or t = 3 months (P = 0.51 and P = 0.31, respec tively). Endothelial cell proliferation and smooth muscle cell proliferatio n at the anastomosis was highest during the 2 weeks after the procedure, th en returned to baseline levels by 3 months. But there was no significant di fference between the clipped and sutured groups with respect to vascular ce ll proliferation postoperatively. The intimal thickness changed significant ly in the vein graft at the anastomosis for both the clipped and sutured gr oups (P = 0.0007 and P = 0.002), But there was no difference when the intim al changes for each technique were compared (P = 0.94). Conclusion. No differences were observed when peak systolic velocity, vascu lar cell proliferation, and intimal changes were compared between sutured a nd stapled anastomoses in rabbit vein interposition grafts over a period of 3 months after surgery. (C) 2000 Academic Press.