Complete prevention of impaired anastomotic healing in diabetic rats requires preoperative blood glucose control

Uncontrolled diabetes severely impairs early healing of experimental intestinal anastomosis. This study aimed to compare the potential beneficial effect of insulin treatment, started before or immediately after surgery. A normal blood glucose level was attained in diabetic rats by twice-daily administration of insulin, commenced either 4 days before operation (insulin-1 group) or on the day of operation (insulin-2 group). A non-diabetic control group and an uncontrolled diabetic group were also studied. Three days after operation, mean (s.d.) bursting pressures in the diabetic group were severely reduced compared with those in controls: 1.0 (1.4) versus 8.1 (2.9) kPa in the ileum and 4.9 (4.7) versus 18.1 (5.8) kPa in the colon. For ileal anastomosis, values in both groups of animals receiving insulin were similar to those in controls, but for colonic anastomosis the mean bursting pressure in the insulin-2 group remained significantly (P < 0.017) below that in the insulin-1 group (10.2 (6.4) versus 20.7 (7.9) kPa respectively). After 7 days mean bursting pressures in both ileum and colon were restored to control levels in the insulin-1 group but not in the insulin-2 group. Anastomotic abscess formation after 3 days was also significantly (P < 0.017) more common in the diabetic and insulin-2 groups, but not in the insulin-1 group than in the control group. Postoperative blood glucose control alone does not completely prevent the detrimental effects of uncontrolled diabetes on healing intestinal anastomoses.