Role of immediate postoperative feeding on colonic anastomoses resistance. An experimental study in a rat model

This study was performed to investigate whether immediate postoperative feeding induced changes on colonic anastomoses resistance. On the other hand, results was compared with a hyoscine-induced deep paralytic ileus status.

Sixty-three Sprague-Dawley rats were divided into three groups: Group 1 (n = 20; colonic anastomosis + water "ad libitum" + 1 cc of saline solution subcutaneously, daily); Group 2 (n = 21; colonic anastomosis + water and standard rat chow "ad libitum" + 1 cc of saline solution subcutaneously, daily); and Group 3 (n = 22; colonic anastomosis + water "ad libitum" + 2 mg/100 g body weight hyoscine N-butylbromide in 1 cc subcutaneously, daily). Body weight, food intake and water consumption were recorded on a daily basis. Surviving rats (20 in each group) were sacrificed 4 days after surgery and adhesions were evaluated. Each segment containing an anastomosis was removed and the bursting pressure was determined; the diameter and Lapace's law were used to calculate Bursting wall tension (BWT).

The cause of death during the early postoperative period was dehiscence in 2 cases (1 in Group 2 and 1 in Group 3). A rat died in Group 3 due to non-specific side effects. Weight loss was significantly lower and water consumption significantly higher in Group 2 (Food) than in others groups. BWT was lower in Group 2 than in the other groups (53.61 x 10(3) dynes/cm +/- 24.51 x 10(3) dynes/cm in Group 1, 48.94 x 10(3) dynes/cm +/- 18.53 x 10(3) dynes/cm in Group 2 and 65.09 x 10(3) dynes/cm +/- 28.59 x 10(3) dynes/cm in Group 3). Nevertheless only comparison between Group 2 (Food) and Group 3 (Hyoscine) showed statistically significant difference (p = 0.03). In all cases leakage of dye was observed at the anastomotic line. General adhesion scores in Group 2 (Food Intake) were similar than Group 1 (Water only) and higher than in Group 3 (Hyoscine) (p = 0.036).