Diverting colostomy increases anastomotic leakage in the rat colon

In the present study, we examined the effect of a diverting colostomy on the intestinal healing of colonic anastomosis in the rat. For this purpose, we created a colonic stenosis 2 days prior to the formation of a distal one-layer end-to-end anastomosis with or without a proximal double-barreled deviation colostomy in the rats. Radiological examination of anastomotic leakage was performed daily for 4 days and on day 7 after the operation. We found that anastomotic leakage was markedly increased in rats with a diverting colostomy compared to control animals; i.e. the leakage index (percentage of days with leakage during the experimental period) in colostomy rats was 29%, whereas in animals with no colostomy, the leakage index was only 7%. Interestingly, it was observed that anastomosis formation was associated with a higher mortality rate in rats with colostomy diversion (36%) compared to control animals (7%). However, there was no difference in suture holding capacity on day 7. Moreover, body weight decreased significantly in the colostomy group compared to rats without surgical defunctioning when followed for up to 7 days after surgery. Taken together, our novel findings suggest that a diverting colostomy may increase intestinal leakage after anastomosis formation in the rat colon. Thus, the role of proximal colostomy in the protection of colorectal anastomosis needs to be reevaluated and further investigations are required to resolve the influence of surgical defunctioning on intestinal healing.