Assessment of ischaemia of the distal part of the gracilis muscle during transposition for anal dynamic graciloplasty

Background Dynamic graciloplasty is used to create a neosphincter in patients with intractable faecal incontinence. When mobilizing the distal gracilis muscle from the upper leg, the minor vascular pedicles have to be ligated. This can interfere with the vascular supply in this part of the muscle. Methods The arterial anatomy within the muscle was visualized by means of angiography of 11 postmortem specimens. To quantify potential acute ischaemia, blood flow in the distal gracilis muscle was measured in ten patients with laser Doppler flowmetry during mobilization of the muscle. Results Angiography showed that the main vascular pedicle and all minor pedicles drain into one and the same arterial system. After clamping of the minor vascular pedicles, blood flow (mean 25.8 (range 6.5-74.3) perfusion units) did not differ from values obtained before clamping (mean 25.4 (range 7.5-68.7) perfusion units). After a mean of 1.8 years, all muscles were vital. No correlation existed between the change in muscle blood flow and either squeeze pressure (r = -0.2) or functional outcome (r = 0.31). Conclusion This study provides direct anatomical and physiological evidence of one arterial system within the gracilis muscle. It is therefore questionable whether ligation of the minor vascular pedicles is the bottleneck in human dynamic graciloplasty. An additional operation for vascular delay may be redundant. A prospective randomized clinical study should be performed to compare the functional outcome in patients with and without a delay procedure.