Diabetes impairs the development of early strength, but not the accumulation of collagen, during intestinal anastomotic healing in the rat.

The evidence that diabetes mellitus adversely affects healing is derived from data on skin, where diminished wound strength is accompanied by a reduced collagen content. As no such data are available on intestinal anastomotic repair, and it has been reported that collagen metabolism in skin and intestine is affected differently by the diabetic state, anastomotic healing in the rat intestine during uncontrolled diabetes was examined. Wistar rats underwent resection and anastomosis of both ileum and colon 1 week after a single injection of streptozotocin (diabetic group) or citrate (control group). After 3 days the mean bursting pressure of ileal anastomoses was 4.1 kPa in controls and 1.0 kPa in diabetic animals (P < 0.05). For colon, these values were 12.0 and 4.9 kPa respectively (P < 0.05). This negative effect of diabetes persisted after 7 days in ileum but not in colon. Diabetic animals had more anastomotic abscesses, especially in the ileum: nine of 16 animals at 3 days after operation versus one of 15 in the control group (P < 0.01). Anastomotic hydroxyproline concentration and content in diabetic animals were not reduced. The postoperative collagen synthetic capacity, as measured in tissue explants, was strongly stimulated in the wound area and appeared essentially unchanged in the diabetic animals. Uncontrolled streptozotocin-induced diabetes severely impairs the development of anastomotic strength in the rat intestine but, unlike impaired wound healing in skin, this phenomenon is not caused by deficient accumulation of collagen.