Comparative surgical and colonoscopic appearance of colon anastomoses constructed with sutures,staples, and the biofragmentable anastomotic ring

Summary The following animal study was undertaken to compare and assess the endoscopic gross appearance and histology of colonic anastomoses constructed with sutures, staples, and the biofragmentable anastomotic ring (BAR).Methods: Three anastomoses—1 BAR, 1 stapled, and 1 sutured—were placed in each of 48 dogs and colonoscopy and anastomotic evaluation were done.Results: No leaks were found by air insufflation at surgery. Grossly, the BAR had serosal hematomas in 27/48 anatomoses vs 7/48 for stapled and 1/48 for sutured (BAR vs stapledP<0.0005 and sutured vs stapledP=0.07). Adhesions were significantly greater for BAR (35/36) and sutured (34/36) compared to stapled (26/36) (BAR vs stapledP=0.01 and sutured vs. stapledP=0.04). Colonoscopic exams at days 3, 7, and 28 showed no significant difference among groups with respect to bleeding, ulceration, necrosis, granulation, or contour. Sutured anastomoses were more stenotic (24/31) than stapled (4/31) or BAR (3/31) ones (BAR vs sutured and sutured vs stapledP<0.005). At 28 days, 10/10 sutured vs 2/10 stapled vs 3/10 BAR were stenotic (BAR vs suturedP=0.02, sutured vs stapledP=0.01). Inflammation on histologic exam at 28 days was not significantly different: sutured (12/12), stapled (12/12), or BAR (9/12). Fibrosis was more prominent in sutured (12/12) than in stapled (5/12) or BAR (4/12) anastomoses (BAR vs suturedP=0.001, sutured vs stapledP=0.004, and BAR vs stapledP=1.00). All anastomoses healed primarily without necrosis or obstruction.Conclusions: (1) Colonoscopy to evaluate anastomoses can be done safely even in the early postoperative period. (2) The BAR anastomoses had the most serosal hematomas; BAR and sutured had more adhesions than stapled anastomoses; and sutured anastomoses had the most stenosis and fibrosis. None of these differences was of clinical significance.