A New Method for Entero-Enteral Anastomosis

Abstract

Background: Hand-sewn enteral anastomoses are time-consuming at laparotomy and laparoscopy. During NOTES procedures they are extremely difficult. Stapled anastomoses require a two centimeter enterotomy in either bowel limb; this remaining defect must be either stapled or sewn closed. A new method for forming enteroenteral anastomoses (EEA) was developed and tested in bench, non-survival and survival pig models. This method allows EEAs to be formed through incisions 2 mm in diameter. If flexible access is available in one lumen, then only one incision needs to be made. This can be easily performed at open surgery, laparoscopy and NOTES. Methods: A hollow ferrous tube was tapered for insertion over a flexible guidewire. It featured ‘hinges’ to allow shape change during the anastomosis formation. This metal rod (component A) compressed the intervening small bowel tissue against a series of cylindrical hollow neodymium iron boron alloy magnets (component B), that were placed in the other small bowel limb. In NOTES procedures, using a double channel gastroscope, the two limbs to be anastomosed were held together with a suture. Tissue was grasped with forceps and a needle-knife incision allowed a nitinol 0.00035 inch diameter guidewire to be passed into the lumen. Component A was pushed into the lumen using a 7 French plastic pushing catheter. Using a similar method, a guidewire was inserted into the other small bowel limb and the cylindrical magnets were pushed into the lumen, where they locked together on the ante-mesenteric border of the small bowel, compressing the intervening tissue. The length of the anastomosis could be varied by extending the length of the metal cylinder and increasing the number of magnets. This formed a compression anastomosis. The small enteral openings were closed with TAS sutures, clips or 3-0 vicryl sutures. Results: At open and laparoscopic surgery an EEA was created with this technique. Three weeks post-surgery, the anastomoses were identified at autopsy examination. This was completed in 5 pigs, all of whom survived without complications. The autopsy examination revealed no peritoneal soiling, and well- healed anastomotic sites. The anastomoses were patent in all pigs. By NOTES, the EEA was also created using the two components with an anastomosis being formed uneventfully. Conclusion: A new method for enteroenteral anastomosis was developed and tested. The method has advantages over sutured or stapled anastomoses. The enterotomy made is very small. The method is much easier than a traditional anastomosis if a NOTES procedure is being done. The new device was trialed in non-survival and survival studies.