An experimental study on the morphological and histological effects of tension in end-to-end arterial anastomosis in the rat

An experimental study was performed to evaluate the effect of tension on microsurgical anastomosis. A variable length of the common carotid artery in Wistar rats was resected to give variable degrees of tension and the artery reanastomosed microsurgically. Forty-two (42) Wistar rats were divided into 7 groups of six rats each according to the relative length resected. Repaired arteries were then compared histologically and functionally with the artery of the contralateral side, submitted to a simple section followed by a microsurgical anastomosis. Significant histological changes occurred when the length of the resected segment was greater than 13.33% of the vessel's total length. These changes included subendothelial hyperplasia, media necrosis and thrombosis. The results of this study lead us to the conclusion that the small degrees of tension (< 13.33% of the total length in this study) have no significant effects on patency of microanastomosis. Greater tension results in changes in the laminar flow through vessels that can adversely affect patency. There are also significant histological changes that have detrimental effects in the long term.