Minimally-Invasive Creation of Durable Jejuno-Ileal Side-to-Side Anastomosis Using Self-Assembling Magnets

Marvin Ryou, MD, Hiroyuki Aihara, MD, PhD, Christopher C Thompson, MD, MHES. Brigham & Women’s Hospital

Introduction: A minimally invasive method of gastrointestinal bypass would be desirable for treatment of obstruction, obesity, or metabolic syndrome. We have developed a technology based on miniature self-assembling magnets which create large-caliber anastomoses (Incisionless Anastomosis System or IAS).

The IAS magnets can be deployed into a lumen endoscopically or laparoscopically. The IAS magnet self-assembles into an octagonal macro-magnet which then couples with an identical macro-magnet deployed in an adjacent lumen. The magnets form a large anchored window for immediate bypass if desired. Otherwise, magnetic compression over several days creates a robust durable anastomosis, and the fused magnets are naturally expelled.

Aims: To assess (a) procedural characteristics of IAS deployment and (b) long-term integrity and patency of the resulting jejuno-ileal side-to-side anastomosis

Methods: Endoscopic jejuno-ileal bypass creation using IAS magnets was performed in 8 Yorkshire pigs survived 2 months. Procedure: Enteroscopy was performed to deploy the jejunal magnet. Given porcine anatomy (i.e. corkscrew colon and inability to endoscopically reach the ileum) a laparotomy was performed to identify ileum approximately 50-100 cm proximal to the cecum. A 3 mm enterotomy was created through which the ileal IAS magnet was inserted using a modified laparoscopic delivery tool. The magnets were manually coupled. Pigs underwent serial endoscopies for anastomosis assessment. Necropsies were performed at 2 months followed by pressure testing of anastomoses and histological analysis.

Results: Jejuno-ileal bypass creation using self-assembling IAS magnets was successful in all 8 pigs (100%). Patent, leak-free bypasses had formed by post procedure Day 3. All IAS magnets had fused and were expelled by Day 12. Anastomoses were fully patent at 2 months, with mean maximal diameter of 30 mm. At necropsy, adhesions were minimal. Pressure testing showed anastomotic tissue to be stronger than native bowel wall in all animals (i.e. leak point was never anastomosis). Histology showed full epithelialization across the anastomosis with no evidence of submucosal fibrosis or inflammation. Video logs were kept throughout.

Conclusions: Entero-enteral bypass using self-assembling IAS magnets is safe and technically feasible in the porcine model. IAS magnets can be rapidly delivered endoscopically or through a modified laparoscopic device. Expulsion of fused magnets avoids retention of prosthetic material. Anastomoses are widely patent and fully re-epithelialized. 2-month pressure-testing reveals anastomotic tissue to be more robust than native tissue, while necropsy and histology suggest minimal/absent tissue inflammation. In human anatomy, a purely endoscopic jejuno-ileal bypass using IAS magnets may be feasible.

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