An investigation of the effects of suture patterns on mechanical strength of intestinal anastomosis: an experimental study.

How the distance of sutures from the edge of tissue and the horizontal distance between stitches affect the mechanical strength of anastomosis is investigated. In this study, 180 bovine intestines were used to investigate the optimum pattern in 18 groups by considering a 4, 6, and 8 mm horizontal distance between stitches, and a 3, 5, and 7 mm distance from the edge of tissue with 3-0 Silk and 3-0 PDS sutures to maximize the strength of anastomosis (10 specimens in each group). Also, 80 specimens were used to investigate the maximum effective distance of sutures from the edge of tissue in eight groups of: 3, 5, 7, and 10 mm distance from the edge, with the same type of sutures. Tensile tests with an elongation rate of 5 mm/min were performed for all the groups. Based on the results, the pattern of 7-6 (distance from the edge-distance between stitches) for both 3-0 Silk and 3-0 PDS, 5-6 and 7-4 for 3-0 Silk, and 5-6 and 7-4 for 3-0 PDS can be considered as the best options among 18 different combinations. It was also found that increasing the distance from the edge from 7 mm to 10 mm does not cause a significant difference in mechanical strength. Results can help surgeons to improve the intestinal anastomosis and employ it as an input for automatic suturing devices.