A novel artificial magnetic sphincter to prevent fecal incontinence (preliminary study).

In this research we propose an original magnetic device to strengthen the hypo-atonic anal sphincter and prevent fecal incontinence. METHODS: The device consists in a couple of small magnetic plaques to be surgically inserted in the wall of the anal canal between the external and internal anal sphincters with the opposite polarities face to face, so that, attracting themselves, close the anal lumen. Three couples of magnets made of materials of different magnetic force (neodymium>ferrite>plastoferrite) were evaluated in each of three swine anatomical preparations by measuring the endoanal pressure with a manometric catheter, both before and after magnet implantation. The mean pressures obtained before and after magnet insertion were statistically compared with Student t test. RESULTS: The endoanal pressure after the insertion of neodymium magnets was 79.7+/-13.1 (mean+/-SD), after ferrite magnets was 42.1+/-5.6 mmHg and after plastoferrite magnets was 21.6+/-4.6 mmHg, all of them significantly higher than the pressure recorded in basal conditions (1.72+/-0.71 mmHg). CONCLUSION: This research demonstrated that the implantation of a couple of magnets in the wall of the anal canal is able to create a high pressure zone of a value sufficient to prevent fecal incontinence and that the strength of this "dynamic closure" can be modulated by using magnets of various attraction force, so allowing a "tailored correction" of the anal sphincter hypotension.