OBJECTIVETo compare microcirculation and tissue healing process in gastrointestinal anastomosis with apposition or inverted suture.

METHODSThe study was performed in adult rabbits. Animals were randomly assigned to two groups. In group A, small intestine was transected at 20 cm and 40 cm from duodenojejunal ligament and apposition sutures were performed at 20 cm and inverted sutures at 40 cm. In group B, transaction and anastomosis were at the same location with group A while the suturing method was reversed. Anastomotic microcirculation and number of capillary were observed in vivo with naked eyes to evaluate inflammatory response, collagen proliferation and healing of epithelium and smooth muscle in both groups at postoperative day 3, 7, 14 and 28.

RESULTSIn group A, tissue layers at the anastomosis were approximated tight and neat with mild inflammation and primary wound healing. In group B, displacement and poor alignment of layers were seen with severe inflammation and secondary wound healing. Low frequency of microcirculation was detected in group A at day 3, and blood flow velocity significantly increased at day 7. Blood flow velocity was close to normal at day 14 and completely restored to the normal level at day 28. Microcirculation was lower in group A than that in group B at each time point. There were more capillaries, lower number of inflammatory cells, less collagen proliferation, and better healing of anastomotic epithelium and smooth muscle in group A than group B.

CONCLUSIONApposition suturing is better than inverted suturing in restoring local anastomotic microcirculation and healing of intestinal tissues.