A pair of medical magnets shows promise as a tool for creating an anastomosis
An experimental device that employs a pair of magnets offers surgeons a new safe and simple alternative to standard methods for creating an anastomosis for the first time in nearly 50 years. An anastomosis is a surgical connection between tubular anatomic structures, such as blood vessels, urinary tract, or bowel. In its first proof-of-concept clinical trial in humans, the device was easy for surgeons to use, even with patients who required complicated surgical reconstruction. It also was safe; none of the patients had any complications related to the use of the device or the anastomosis it fashioned.
An anastomosis is common in many kinds of operations performed by general surgeons. It currently is done in one of two ways. The first approach involves suturing two pieces of tissue together with a needle and thread. This option is inexpensive and can be done in any surgical setting. However, suturing requires either an open operation so surgeons have enough room to manoeuver instruments, or highly specialized technical skills in minimally invasive procedures, and it takes time to place multiple layers of sutures during a procedure, said Claire Graves, MD, lead author and research fellow at the University of California San Francisco when the study was conducted. When surgical staplers were introduced in the 1970s, stapling often became the preferred method for performing an anastomosis. Stapling is faster than suturing, and it produces a more consistent result. Staples are, however, expensive, and the devices can sometimes fail or misfire, added Dr. Graves, a current resident in general surgery at Columbia University Medical Center, New York City.
Magnetic compression anastomosis applies the force of magnetic attraction to form an anastomosis without sutures or staples. The technique utilizes a Magnamosis device, which houses two rare earth magnets in a specially engineered medical grade polycarbonate shell. The magnetic implants have different polarities so they are drawn to one another. The magnets also have different shapes--one is convex and one is concave--so they fit smoothly together. In the formation of an anastomosis, a magnet is placed in each side of the tube that is being surgically connected, and then the magnets are drawn together, compressing the tissue between them and blocking blood flow.
“The tissue between the magnets dies off, a hole forms from the necrotic tissue, and the surrounding area heals. Once the connection is fully formed, the magnets fall through the hole, pass into the bowel, and are excreted in the stool, leaving nothing behind,” Dr. Graves explained. In animal studies, the Magnamosis device consistently created anastomoses that were comparable or better than hand-sewn or stapled alternatives as demonstrated in tissue samples and tests of the strength of the connection.
American College of Surgeons