Compression anastomosis for Roux-en-Y gastric bypass: observations in a large animal model

BackgroundIn the morbidly obese, laparoscopic Roux-en-Y gastric bypass (RYGB) effectively achieves weight loss with the resolution of co-morbidities. The goal is to create a small-volume gastric pouch with a narrow gastrojejunal anastomosis (GJA). The procedure is associated with a GJA stricture rate of approximately 3%. The use of a compression anastomotic device to create a sutureless gastrointestinal anastomosis, replacing sutures or staples, might reduce tissue trauma and improve the GJA patency rate. A temperature-dependent, memory-shape, Nitinol Compression Anastomosis Clip (CAC) has been successfully used in intestinal anastomoses. Compression of the entrapped bowel leads to necrosis, with device expulsion after 7–10 days.MethodsWe designed a pilot animal model study of open RYGB to examine the clip’s safety in the performance of upper gastrointestinal anastomoses. Six 40-kg female pigs underwent RYGB. Group 1 (n = 3) underwent GJA with the CAC and a stapled jejunojejunal anastomosis (JJA). Group 2 (n = 3) underwent GJA and JJA with the CAC. One pig from each group was euthanized at 1, 4, and 8 weeks postoperatively.ResultsTwo pigs, one from each group, developed gastroparesis. At autopsy, all anastomoses were patent; the mean GJA diameter with the CAC was 1.6 cm (range 0.6–3), the mean JJA diameter with the stapler was 3.8 cm (range 35–40), and the mean JJA diameter with the CAC was 3 cm (range 3–3.2). Anastomotic burst pressures were similar between the stapled and CAC anastomoses. The device was passed per rectum by postoperative day 9 (range 8–12). Histologic examination of the CAC anastomoses demonstrated a complete mucosal lining with no evidence of stricture formation at 2 months.ConclusionThe results of this small animal study have demonstrated the safety of sutureless compression anastomoses in an animal model of open RYGB.