Comparison of consequent small bowel anastomoses after transient ischemia: an experimental study in rats.

Background/purpose: The role of ischemia/reperfusion (I/R) damage on intestinal anastomotic healing remains to be precisely determined. The objective of this study was to investigate healing of small bowel anastomoses performed at different times after transient ischemia.

Methods: Thirty male Wistar-Albino rats were investigated in five groups (four study and one control). Under general anesthesia, the superior mesenteric artery (SMA) was occluded for 40 minutes in the study rats. Biopsy specimens, to document I/R histopathology, were obtained before small intestinal anastomoses at 20 minutes (group 1), 90 minutes (group 2), 6 hours (group 3), and 24 hours (group 4) after reperfusion. In a control group, biopsy and intestinal anastomoses were performed after SMA dissection without occlusion. The rats were relaparotomized on the fifth day to determine in situ bursting pressures and to obtain specimens for hydroxyproline content and histopathologic evaluation.

Results: Hydroxyproline content and bursting pressures were compared statistically with Mann-Whitney U test. Although there was no statistical difference between the control group and group 1, there were significant differences (P < .05) between groups 2, 3, and 4, with both parameters decreasing as the duration after reperfusion increased.

Conclusion: Anastomosis are less likely to leak when performed sooner rather than later after an ischemia/reperfusion event.