Long-term follow-up of a novel anastomotic device in a canine model

Construction of intestinal anastomosis is a fundamental general surgery skill. New constraints in creating safe, effective anastomoses are faced, however, even as minimally invasive surgery techniques continue to gain popular and scientific support. We present our experience in developing and testing a novel anastomotic device (AD) constructed of a shape memory metal, with long-term follow-up in a canine model. This device has the potential for both laparoscopic and endoscopic delivery because of its unique design and adaptable deployment system. Eight canines had gastroduodenal and jejunojejunal anastomoses formed with the AD: the gastroduodenal anastomosis by transecting the stomach immediately distal to the pylorus and forming a side-to-side functional end-to-end anastomosis and the jejunojejunal anastomosis similarly following transection in the mid-jejunum. Four animals were survived for 6 months, and 4 for 12 months. At the study's end, the animals were euthanized and the anastomotic sites harvested for both gross and microscopic pathology. Two animals developed postoperative complications: one a mechanical bowel obstruction from bedding ingestion that required laparotomy, and one an ileus that conservative management resolved. All animals survived to their endpoints, displaying normal growth and development. All jejunojejunal anastomoses had AD passage and microscopic evidence of complete healing. Meanwhile, none of the gastroduodenal devices passed, with microscopy demonstrating incomplete mucosalization. This AD is highly effective in forming jejunojejunal anastomoses. Gastroduodenal anastomoses, while highly functional, retained the device without complete healing. Future studies using a more human-like animal model and an anastomotic technique avoiding the thick pylorus muscle should yield better results.