In cases of Fournier’s gangrene with severe perineal involvement, the anal sphincters may be directly involved by the infection, necessitating the debridement of the structure, with the drastic morbidity of anal incontinence. Anal sphincter reconstruction is thus required in such cases but difficult to achieve [2]. The estimated percentage of patients requiring end colostomy after radical debridement in Fournier’s gangrene is approximately 15% [3].
The use of unilateral or bilateral gracilis flap for anorectal reconstruction following abdominoperineal reconstruction [4], anal incontinence which may be secondary to trauma iatrogenic causes [5] or even anorectal malformation [6], have been described widely in the literature. Gracilis is a muscle that exhausts quickly due to the fast-twitch fatigue-prone muscle fibers (type II muscle fibers). In the past, electrostimulation is commonly used after the graciloplasty to transform the gracilis muscle from type II to type I (slow-twitching fatigue-resistant fibers), which allows the gracilis muscle to work as a new sphincter, and maintain a sustained contraction [7]. However, in most of these cases, they only achieved partial continence at best, with continued faecal leakage requiring diapers still, The success of conventional graciloplasty has been less than 50% mainly due to muscle fatigue and the inability of patients to voluntarily contract the transposed muscle5.Gohil et al. described the use of a single gracilis muscle wrapped around the anus in a “alpha”, “epsilon”, and “gamma” configuration, and showed that satisfactory continence was achieved in 76.4% of the patients in adynamic gracilis reconstruction [7]. Rouanet et al. used a gamma configuration for each gracilis muscle, and fixed both muscles to each other to create a double gracilis wrap. With electrostimulation as the next stage after the double gracilis wrap was performed, the study showed 5 out of 9 patients who were continent for solids (55.6%) [8].
In our case report, we described a novel way of inset that makes use of the orthograde contraction of the double gracilis flaps to narrow and collapse the neo-anal opening. This is akin to the way a camera shutter closes, by “sliding and shuttering” the aperture close. The neurovascular pedicle of the gracilis muscle is carefully preserved so that the it is still a functioning muscle. Through biofeedback exercises, we instruct the patient to imagine adducting his thighs, and due to the nature of inset, the orthograde contraction of the double gracilis muscle will be converted to a shuttering action, effectively closing the neo-anus. A committed and compliant patient is necessary for the success of this technique, as our patient only achieved full continence after 1 year of training. This is an effective technique of creating a dynamic anal sphincter that relies purely on the pulley action of anchoring sutures to create a double opposing contracture of the gracilis flaps, resulting in a “camera shutter” action. Without the need for electrostimulation, patient can reliably go off the end-stoma without need for long term follow-up with electrical implants or devices. It can be thought of as a mechanical solution to an electrodynamic problem.