Laser welding and irradiation in alcohol preserved homografts.

This experiment examined the effect of laser welding and irradiation on the patency rate of microvascular anastomoses done with alcohol preserved homografts. The carotid arteries from Sprague-Dawley rats were freshly harvested and preserved in 70% ethyl alcohol for at least 3 weeks. The homografts were interposed into the carotid arteries with one of the following techniques: Group I, grafts were anastomosed with three stay sutures and laser welding (carbon dioxide laser, 90 mW); Group II, anastomoses were completed with eight to nine interrupted sutures (10-0 nylon); or Group III, the same technique used in Group II, but followed by laser irradiation (90 mW for 1 min) of the grafts. These results showed that patency at 2 weeks was 73% in Group I, 71% in Group II, and 82% in Group III, respectively. The patency at 12 weeks was 67% in Group I and unchanged in Groups II and III. In conclusion, laser irradiation and laser welding did not increase the patency rate of microvascular anastomoses done with alcohol preserved homografts. Thrombotic occlusion in microvascular homografts usually occurs before the second week postoperatively.