Local ischaemia does not influence anastomotic healing: an experimental study

The role of local ischaemia in the pathogenesis of colorectal anastomotic leakage (AL) is not known. This study investigates the role of local ischaemia caused by sutures in an experimental colonic anastomosis model. 36 mice were assigned to three types of anastomosis, all using running sutures; in the first group 5 stitches were used, in the second group 12 stitches were used, and in the third group at least 30 stitches were used. After 7 days the mice were re-operated, signs of AL were scored, and coronal sections of the anastomosis were histologically analyzed. The distribution of weight was not significantly different between the three groups. Mortality was 44% and not significantly different between the groups (group 1: 5/12, group 2: 4/12, and group 3: 7/12, p = 0.72). Faecal and purulent AL were observed in 6 animals in group 1, 2 in group 2, and 3 in group 3 (group 1: 50%, group 2: 17%, and group 3: 25%, p = 0.19). The distance between the two colonic edges (group 1: 0.51 μm, group 2: 1.34 μm, and group 3: 0.53 μm, p = 0.18), the diameter of the lumen at the site of the anastomosis (group 1: 2.92 μm, group 2: 4.06 μm, and group 3: 3.2 μm, p = 0.9), and the largest diameter of the lumen proximally to the anastomosis (group 1: 2.05 μm, group 2: 3.1 μm, and group 3: 2.6 μm, p = 0.25) were not different between the groups. Histological parameters of wound healing were not significantly different for the three groups. In this study no macroscopic and microscopic differences were observed between colon anastomosis with 5 stitches versus 12 and >30 stitches. This might indicate that local ischaemia does not negatively influence colonic wound healing.