New magnetic device forms small-bowel anastomoses

Last Updated: 2017-08-31

By Will Boggs MD

NEW YORK (Reuters Health) - A new magnetic device can be used to form compression anastomoses of the small bowel without sutures or staples, a small pilot trial suggests.

The Magnamosis device is a pair of self-centering, rare earth magnets encased in a polycarbonate shell that is placed within the lumen of each segment of intestine where the anastomosis is desired. When the two rings are mated, the interposed tissue is compressed, causing necrosis and anastomosis formation. To ensure immediate patency, a hole is created with cautery, under direct vision, between the central portion of the mated rings. With healing, the device passes through the newly formed anastomosis and leaves no foreign bodies.

Dr. Claire E. Graves at the University of California, San Francisco and colleagues have obtained an FDA Investigational Device Exemption to perform magnetic anastomosis in 10 human subjects to ensure safety and efficacy of the device.

In a paper online August 23 in the Journal of the American College of Surgeons, the researchers describe the first five patients in their series, in whom the new device was used to restore small-bowel continuity after isolation of an ileal segment during complex open urinary reconstruction procedures.

Three of the five study participants were quadriplegic and bedridden. Two patients had end-stage renal disease requiring hemodialysis. Three had previous abdominal surgeries, and all five had undergone multiple previous urologic operations.

The device was safely and successfully employed in every case, and passage of the device was confirmed in all cases at two to eight weeks after surgery, according to the authors.

During follow-up ranging from six to 18 months, no patients had complaints related to their intestinal anastomosis, and none experienced any complications related to the magnet, including anastomotic leak, bleeding, or stricture.

Four patients experienced surgical complications unrelated to the small intestinal anastomosis. In one of these four, who required surgical exploration for an unrelated adhesive obstruction at three months, the anastomosis "was intact, patent, and well-formed," the authors report.

"One of the most exciting aspects of the device is its flexibility," Dr. Graves said. "It can entirely replace sutures or staples in any part of the gastrointestinal tract, and could also be scaled down for uses elsewhere, such as in the biliary or urinary systems. Where we think it could provide the greatest benefit is in minimally invasive or NOTES (natural orifice translumenal endoscopic surgery) procedures, where the device can be delivered and deployed endoscopically."

"We expect to be able to manufacture the Magnamosis device at a significantly lower cost than current surgical staplers," she said. "While sutures will likely remain the lowest-cost option in terms of equipment, hand-sewn anastomoses add significant, costly operative time. We expect, by taking both device cost and operative time into account, that our device will be the most cost-effective option for GI anastomoses."

Dr. Graves added, "We're always looking for collaborators, so we'd love to invite any surgeons who are interested in being involved in clinical trials to please reach out to us."

Dr. Yuichi Nakaseko from The Jikei University School of Medicine, Tokyo, Japan, who recently used magnets for a duct-to-duct biliary anastomosis, told Reuters Health by email, "Magnetic compression anastomosis is a minimally invasive procedure. So it is ideally suited for patients who are difficult to operate because of advanced age, have strong adhesions from repeated operation, and for patients who have failed other approaches."

Dr. Nakaseko said he plans to investigate the use of magnetic compression anastomosis for patients undergoing colostomy.

Two of the seven authors have various financial interests in Magnamosis Inc., which manufactures this device.

SOURCE: http://bit.ly/2vBcH9c

J Am Coll Surg 2017.