A Sutureless Vascular Closure Device for Emergent Bovine Xenograft Implantation.

A novel vascular staple (C-staple) was developed that does not enter the vasculature lumen during anastomoses. The objective of this study was to demonstrate C-staple safety when used with a bovine xenograft and compare efficacy of the C-staple procedure with Anastoclip surgical clips or suturing when used with a bovine xenograft. Eight sheep had an acute comparison between suturing and C-staples using both common carotid arteries. Sixteen sheep had xenograft placement in the left carotid artery, eight with C-staples and eight with Anastoclips in a chronic study. Over 6 months, Doppler ultrasound interrogation of the common carotid arteries was performed. After 6 months, arteries were evaluated histopathologically. Cross-clamp and surgical times were longer in the C-staple group than the suture group, and xenograft implantation times were statistically longer with C-staples than with Anastoclips. After 6 months, C-staple biocompatibility was similar to Anastoclips. Patency and hemodynamics of the bovine xenograft were not statistically different between the two groups. C-staples performed as well as the Anastoclips except for implant times, likely due to delivery system differences. Histological findings and clinical outcomes were no different with the two devices. Further refinements of the C-staple delivery system are necessary before proceeding to clinical trials.

Evaluation of a Bovine Vascular Graft in Sheep.

The study objective was to determine safety and efficacy of a treated bovine vascular xenograft, in two Good Laboratory Practice compliant studies in sheep following carotid graft implantation. In one study, a 3- to 5-mm diameter xenograft was implanted into the right carotid artery of male sheep and compared to autologous jugular vein and a polymeric grafts similarly implanted. In a second study, a 9.5- to 14-mm diameter xenograft similarly implanted into the right carotid artery was compared to an autologous saphenous vein. Monthly Doppler ultrasound evaluation of implant patency and flow in implants and contralateral control carotid arteries was performed. The small vessel cohort 6 month xenograft patency was equivalent (or better) than animals with polymeric vascular graft or autologous vein implants; the aneurysm incidence was less than that of autologous vein grafts. In the large vessel cohort, all 15 xenografts and 12/15 saphenous vein implants were patent at 6 month follow-up. Tissue histology showed mild inflammatory responses in the xenografts that was slightly greater than suture material. In summary, treated bovine xenograft performance in this small study suggests it may be superior to polymeric autologous vein grafts, and may have a similar failure rate as autologous vein grafts after implantation.