Effect of persistently elevated intraabdominal pressure on healing of colonic anastomoses

BACKGROUND: The adverse effects of elevated intraabdominal pressure (IAP) o n abdominal organs are realized, but its influence on anastomotic healing h as not been studied. The aim of this study was to evaluate the effect of el evated IAP on healing of colonic anastomoses. METHODS: Thirty rats, which all had right colonic anastomoses, were divided into five groups. Group 1 was the control group, and group 2 had fecal per itonitis. IAP was maintained between 4 to 6 mm Hg in group 3, 8 to 12 mm Hg in group 4, and 14 to 18 mm Hg in group 5 until all rats were sacrificed o n day 4. Bursting pressures and tissue hydroxyproline concentrations of ana stomoses were then analyzed and compared. RESULTS: Mean +/- SEM of bursting pressures were 143 +/- 2.9 mm Hg in group 1, 72 +/- 14.4 mm Hg in group 2, 77.3 +/- 7.9 mm Hg in group 3, 57.5 +/- 1 1.2 mm Hg in group 4, and 40.1 +/- 9.6 mm Hg in group 5 (P <0.0001, one-way analysis of variance [ANOVA]). Mean +/- SEM of tissue hydroxyproline conce ntrations were 5.3 +/- 0.3 mu g/mg in group 1, 4.7 +/- 0.5 mu g/mg in group 2, 4.6 +/- 0.6 mu g/mg in group 3, 3.6 +/- 0.5 mu g/mg in group 4, and 2.4 +/- 0.2 mu g/mg in group 5 (P = 0.0026, one-way ANOVA). The bursting press ure and hydroxyproline concentrations had good correlation (P <0.001, r = 0 .76). CONCLUSIONS: Elevated IAP delays healing of colonic anastomoses and 4 to 6 mm Hg IAP delays healing as much as fecal peritonitis. More elevated IAP de lays healing more than fecal peritonitis. These events may be clinically im portant and may result from local-systemic effects of IAP. (C) 1999 by Exce rpta Medica, Inc.