High submucosal blood flow and low anastomotic tension prevent anastomotic leakage in rabbits

In many cases of long-gap congenital esophageal atresia, direct anastomosis is difficult. In these cases, the esophagus is first lengthened by myotomy before anastomosis. We determined the degree of submucosal blood flow and/or approximation force at the site of anastomosis in rabbits after (1) separation of the esophagus from the outer membrane, (2) 1 cm and 2 cm resection of the esophagus, and (3) circular or spiral myotomy of the esophagus after 2 cm resection. In the first experimental group, submucosal blood flow volume < 115.2 ml/min/100 g resulted in anastomotic leakage. In the second experimental group, a 1 cm resected esophagus with an approximation force of 33.3 +/- 8.2 g did not result in leakage, while a 2 cm resected esophagus with an approximation force of 111.7 +/- 13.3 g resulted in leakage. It was found that leakage occurred when the approximation force was higher than 49.1 g even if submucosal blood flow volume was greater than 131.8 ml/min/100 g. In the third experiment, both circular and spiral myotomy reduced the approximation force. Although there was no difference in the changes in submucosal blood flow volume between the two types myotomy, circular myotomy was superior to spiral myotomy in the reduction of the approximation force at the site of anastomosis. We conclude that both approximation force and submucosal blood flow are important factors in preventing anastomotic leakage.