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

Background: In 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.
Methods: We 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.
Results: Two 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.
Conclusion: The results of this small animal study have demonstrated the safety of sutureless compression anastomoses in an animal model of open RYGB.