REPERFUSION INJURY DELAYS HEALING OF INTESTINAL ANASTOMOSIS IN A RAT

BACKGROUND: Revascularization of ischemic bowel may induce further loc al tissue damage due to reperfusion injury. Therefore, we aimed to inv estigate the effect of ischemia-reperfusion injury on the healing of i ntestinal anastomosis in experimental models, METHODS: One hundred and two male Wistar rats were divided into three groups: a control group (group I, n = 23); an ischemia group (group II, n = 32), in which only the superior mesenteric artery (SMA) was occluded for 30 minutes; and a profound ischemia group (group III, n = 47), in which SMA was occlu ded as well as collateral vessels for 30 minutes. The pulsations were seen to return to marginal vessels and the bowels began to appear pink er and healthier in all groups following the restoration of arterial f low. Then, all animals underwent a 3-cm ileal resection and primary an astomosis, 10 cm proximal to the ileocecal valve. Within each group, a nimals were anesthetized either on the third or seventh postoperative days. Abdominal wound healing, intra-abdominal adhesions, anastomotic complications, anastomotic bursting pressure measurements, and burstin g site were recorded. RESULTS: Statistically significant differences w ere detected in intraperitoneal adhesion scores in group II and III (P <0.001). Anastomotic dehiscence was found in 2 of 23 (9%) in group I, 5 of 32 (16%) in group II, and 16 of 47 (34%) in group II (P <0.001). On the third and seventh days, the median bursting pressures of the a nastomosis were determined to be 42 mm Hg and 250 mm Hg in group I, 46 and 253 in group II, and finally 19 and 90 mm Hg in group III (P <0.0 1). The burst occurred at the anastomoses in all animals tested on the third postoperative day, none in group I, 4 (28%) in group II, and 8 (67%) in group III on the seventh postoperative day (P <0.005). CONCLU SION: The present study demonstrated that ischemia-reperfusion impairs anastomotic healing. Despite the fact that the intestines are well pe rfused and viable after revascularization, one must bear in mind that intestinal reperfusion may compromise anastomotic healing. (C) 1998 by Excerpta Medica, Inc.