Advantages of sharp adventitial dissection for microvascular anastomoses

Adventitia is usually removed from arteries to simplify microvascular anastomoses. Some surgeons peel the adventitia away bluntly whereas others trim the adventitia sharply with scissors. We used a rat cremaster flap for intravital microscopy to evaluate these two techniques. Animals with unmanipulated vessels, without anastomosis or adventitial removal, served as controls. Fifty-four rats were studied in three groups of 18 rats. Functional capillary density, red blood cell velocity, diameter of the flap's feeding artery (A1), microthrombi formation, and neutrophilic activity were studied for 5 hours following anastomosis, and 24 and 72 hours later. Histological changes in blunt and sharply prepared arteries were compared with control vessels. After blunt preparation, capillary perfusion was reduced to 61% of control values (p < 0.05) and A1 diameter was reduced to 77% of control values (p < 0.05). Capillary perfusion and A1 diameter were unchanged in sharply prepared arteries. Architectural changes in the vessel wall were more profound, and neutrophilic activity was increased in bluntly prepared arteries. In this study, sharp preparation of small arteries was beneficial compared with blunt preparation.