Gross and histopathological findings following serosal and mesenteric onlay grafting for intestinal anastomosis in canines

A total of 24 dogs irrespective of the sex were randomly divided into three groups of eight each. Following laparotomy, a 10 cm long piece of intestine was resected in all the dogs. In group I, anastomosis was performed by two layer inversion technique. In groups II and III, resected ends of the intestine were anastomosed by single layer of simple continuous apposition suture and onlay grafting with fresh serosa and mesentery, respectively. The grafts were prepared from the resected pieces of intestine. The healing process was assessed by macroscopic and microscopic studies on 7, 14, 21 and 30 postoperative days. Macroscopic examination of control group (Group I) showed obstruction at the site with proximal ballooning of intestines in one dog. Adhesions between anastomotic site, mesentery, omentum and abdominal wall were noticed in all three groups. These were moderate in serosal onlay grafted group and mild in mesenteric onlay grafted and control groups. Gross and microscopic findings showed no graft rejection in grafted groups and were well accepted. Mesentery grafted group animals showed early epithelialization, muscular alignment and healing by 21^st day, whereas serosal grafted group showed complete epithelialization by 30^th day. Epithelialization was not complete even on 30^th postoperative day in control group.