Either one long incision or three small incisions are made in the medial thigh. The gracilis muscle is identified and mobilized toward its insertion onto the medial aspect of the tibia where the tendon is divided. Anterior and posterior perianal incisions are made approximately 1.5 cm from the anal verge. Tunnels are developed in the extrasphincteric space and from the proximal thigh to the anterior perianal incision. The gracilis muscle is then gently delivered to the anterior perianal incision, guided around the anus to the posterior perianal incision, and returned to the anterior incision encircling the anal canal. The distal tendon of the gracilis is passed behind the muscle and anchored to the contralateral periosteum of the ischium. In cases when there is inadequate length, it can be sutured to the ipsilateral ischium. This procedure can also be performed bilaterally. In patients with a large rectovaginal fistula or cloaca, a myocutaneous ﬂap can be mobilized and used to help close the defect. Improvement of fecal incontinence is caused by passive increase of the resistance of the anal canal by the bulk of the encircling muscle (Fig. 28.5).
Experimental efforts to improve the efficacy of this procedure have focused on developing resting tone in the transposed muscle through the use of an implanted neurostimulator. The intent of the stimulated graciloplasty is to convert the fast-twitch muscle fibers into slow-twitch muscle fibers, which are more fatigue resistant. Initially, implantation of the pacemaker was performed at 6 weeks after the graciloplasty, but now most are performed concomitantly. Stimulation can be applied directly to the obturator nerve or intramuscularly to the nerve branches inside the muscle. The muscle is stimulated at a cyclic frequency, with gradual increases every 2 weeks. After 2 months, continuous stimulation is performed. Stimulation is adjusted to maintain tonic contraction around the anus, and it is interrupted or turned off to defecate.
An exhaustive review of the published literature identified 37 articles on patients undergoing dynamic graciloplasty (134). Most of these articles were case series, and there were no randomized trials or cohort studies evaluating safety and efficacy. Mortality rate was 1% (range 0%–13%; 95% CI, 1%–3%) after excluding cancer deaths. There was a high rate of morbidity
Figure 28.5 Graciloplasty. A: The gracilis muscle is identified and mobilized toward its insertion onto the medial aspect of the tibia where the tendon is divided. B: Anterior and posterior perianal incision are made approximately 1.5 cm from the anal verge. The muscle is then tunneled around the extrasphincteric space circumferentially. The distal tendon is passed behind the muscle and anchored to the contralateral periosteum of the ischium.
(1.12 events per patient). Most patients will have at least one adverse event, and several will have multiple complications. There is also a very high reoperation rate. The most common complications were infections (28%), stimulator and lead faults (15%), and leg pain (13%). Satisfactory continence was achieved 42% to 85% of the time, although satisfaction was not defined consistently across studies. The authors concluded that dynamic graciloplasty appeared to have equal or better efficacy than colostomy but carried a higher morbidity rate. Another review of