Colonic mucosal-submucosal blood flow and the incidence of faecal fistula formation following colostomy closure.

Fistula formation following closure of a colostomy occurs most frequently when closure is carried out within the first few weeks of construction and may be related to an impaired local microcirculation. Using a recently described method for measuring colonic mucosal-submucosal blood flow, the variations in local flow which occur during the first month after colostomy construction were determined in 8 patients. Mean blood flow increased from 6.9 +/- 1.8 ml min-1 100 g-1 (s.d.) at 7 days to 31.1 +/- 12.5 ml min-1 100 g-1 (s.d.) at 28 days. In a further 40 consecutive patients undergoing colostomy closure, blood flow measurements were made before operation. Eight patients developed a faecal fistula, and in 5 of these patients mucosal-submucosal blood flow was found to be less than 15 ml min-1 100 g-1. In every successful colostomy closure blood flow was greater than 15 ml min-1 100 g-1. This study provides evidence that a subnormal blood flow is one of the factors associated with fistula formation following the operation of colostomy closure.