Butyrate enemas improve intestinal anastomotic strength in a rat model

Anastomotic leakage is a common clinical complication with incidences up to 10% to 17% in colorectal surgery, leading to high morbidity and mortality. Butyrate is the product of colonic fermentation of indigestible carbohydrates and is considered beneficial to gastrointestinal healing. The aim of this study was to investigate the effect of intraluminal supplementation of butyrate on colonic anastomotic strength in a rat model.

Wistar rats were randomly assigned to one of 3 groups (18 animals each). All rats underwent a 1-cm left colonic resection and end-to-end anastomosis with 4 interrupted sutures. Group I underwent no other treatment and served as the control, group II received daily 5 mL of 60 mM sodium butyrate enemas postoperatively, and group III received placebo enemas. On the third or seventh postoperative day, rats (n = 9 per time point) were anesthetized and anastomotic bursting strength was assessed.

As a consequence of anastomotic leakage, 3 rats (16.6%) in group I, 1 rat (5.6%) in group II, and 2 rats (11.2%) in group III died. Mean anastomotic bursting pressures at day 3 were not significantly different between groups (53, 64, and 68 mm Hg for group I, II, and III, respectively, P = .777). At day 7, bursting pressures were 118, 225, and 129 mm Hg for groups I, II, and III, respectively (P = .0006). Group II showed an increased mature-to-immature collagen ratio (P = .035).

Postoperative intestinal butyrate supplementation enhances anastomotic bursting strength in a left-sided partial colonic resection rat model, which can be explained by increased collagen synthesis and maturation.