Effect of tissue tension on magnetic compression anastomosis of digestive tract

With the increasing application of magnetic compression anastomosis (MCA) in gastrointestinal anastomosis, we identified an interesting phenomenon that an anastomosis is more prone to stenosis after endoscopic gastrointestinal MCA. We hypothesized that the increase in tissue tension during endoscopic procedures is the cause of anastomotic stenosis. In this study, we investigated the effect of tissue tension on gastroduodenal bypass MCA in Sprague-Dawley (SD) rats. Twenty SD rats were divided into the study group (high-tension group, n = 10) and control group (no tension group, n = 10), wherein the rats underwent complete gastroduodenal bypass magnetic anastomosis under high tension and no tension of the digestive tract, respectively. Anastomotic specimens were obtained 4 weeks after the operation, and anastomotic diameters of the two groups were observed and measured. The histological difference was observed by hematoxylin & eosin and Masson staining. The operation was successfully completed in all rats, and all survived until 4 weeks postoperatively. Anastomotic measurements revealed that the anastomosis diameter was significantly smaller in the study group than in the control group, and there were three cases of severe anastomotic stenosis. Histological observation showed that the amount of collagen fibers in the anastomosis was greater in the study group than in the control group. The results suggest that the high-tension state of the digestive tract is an important factor leading to anastomotic stenosis, and thus, we put forward the Yan-Zhang's Tissue Tension Theory of MCA to explain this phenomenon.