Evaluation of the long‐term results of vascular anastomosis using polyurethane adhesive and shape‐memory stent in the rat carotid artery model

Introduction In free flaps, 5%–10% of complications are related to failure of sutured vascular anastomoses. Adhesive‐based microvascular anastomoses are potential alternatives but are associated with failure rates of 70% in research studies. VIVO is a new adhesive with slow biodegradation within 6 months that has shown a 100% patency rate in research studies over 2 h observation time but long‐term patency has not been evaluated. The authors hypothesize that VIVO will enable a reliable microvascular procedure comparable to sutured anastomoses over a 28‐day period. Materials and Methods The right common carotid artery of 60 male Sprague Dawley rats, ~450 g, were used for microvascular end‐to‐end anastomosis. VIVO was applied with reduced sutures with a temporary catheter in one group and in the other with a custom‐shaped memory stent. Anastomoses with eight interrupted sutures served as control. All groups were n = 20. Anastomosis time and bleeding were recorded for each procedure. Doppler flowmetry was performed 20 min, 1, 10, and 28 days postoperatively. Postmortem toluidine staining was used for semi‐quantitative analysis of stenosis, thrombosis, necrosis, and aneurysm formation by histologic evaluation. Results No occlusion was detected 20 min and 1 day postoperative, and after 28 days of observation in all anastomoses. The anastomosis time of the VIVO with catheter group was about 32% significantly faster than the VIVO with stent group. In the VIVO group with stent, the bleeding time was ~80% shorter than in the control group with 2.1 ± 0.3 and VIVO with catheter 2.0 ± 0.5 (p ≤ .001 each). Minor and nonsignificant stent‐associated thrombus formation and stent‐typical intraluminal stenosis were detected exclusively in the VIVO with stent group. Conclusion Within the limitations of a rat study, the use of VIVO in anastomosis showed promising results. VIVO with catheter was found to be advantageous.