Clinical applications of magnetic rings in colorectal anastomosis.

Based upon experiments on animals, an anastomotic apparatus, consisting of two magnetic rings of polymer bonded, rare earth cobalt magnets embedded in polyester, was developed. There are three types of polyester device with diameters of 25, 28, and 30 millimeters, respectively. The force between the magnets varied between 2.5 Newtons at 4 centimer separation and 11.8 Newtons at union. For the low colorectal anastomosis, a magnet holder, connecting rod and spherical cap were developed. The aim of the technique is a quick restoration of the underbroken submucosal intestinal cylinder by optimal circular apposition of the submucosal layer. The working mechanism is based upon progressive compression, leading to necrosis of the intermediate mucosal and submucosal layers by increasing the magnetic force while intestinal healing takes place. After seven to 12 days, the magnets cut through the disappear from the anastomotic region by intestinal peristalsis. From the initial series of 21 patients, 11 resections of the sigmoid colon and nine low anterior resections were performed. Dehiscence of the suture line was noted in two instances. One patient required reoperation. The other patient had a small area of dehiscence at the suture line after evacuation of an infected hematoma with a further uncomplicated course. One patient died on the third postoperative day of recurrent myocardial infarction. In the other 18 patients, primary intestinal healing was demonstrated roentgenologically and sigmoidoscopically.