Arterial supply of the gracilis muscle and its relevance for the dynamic graciloplasty.

The various methods of transposition of the gracilis muscle in order to serve as an anal neo-sphincter have progressed in recent years. Tetanic contraction can be achieved by converting Type II muscle fibers into Type I by use of chronic, low frequency electrical stimulation. In order to guarantee a good function the muscle's vascularization has to have at least one nutritive vessel. In our investigation we worked out the various forms of the muscle's arterial blood supply. Dissecting 66 specimens we detected four with only one nutritive vessel, 23 with a double-supply and, as the most common constellation, in 34 cases three supplying arteries. A small group of five individuals showed more than three arterial vessels. Because of the fact that the obturator nerve is not running with the incoming arteries, an angle was measured between the length axis of the muscle and the first perforating artery. This information should help the surgeon to preserve the nerve.