Feasibility of neurovascular antropylorus perineal transposition with pudendal nerve anastomosis following anorectal excision: a cadaveric study for neoanal reconstruction

Current surgical strategies to treat fecal incontinence

Fecal incontinence is a devastating condition, vastly under-reported, and may affect up to 18% of the population. While conservative management may be efficacious in a large portion of patients, those who are refractory will likely benefit from appropriate surgical intervention. There are a wide variety of surgical approaches to fecal incontinence management, and knowledge and experience are crucial to choosing the appropriate procedure and maximizing functional outcome while minimizing risk. In this article, we provide a comprehensive description of surgical options for fecal incontinence to help the clinician identify an appropriate intervention.

Dynamic article: composite antropyloric valve and gracilis muscle transposition for total anorectal reconstruction: a preliminary report

BACKGROUND

Technique and functional outcomes of anorectal reconstruction using an antropyloric graft have been reported previously. This technique had reasonable initial outcomes but lacked voluntary function.

OBJECTIVE

We hereby report the initial results of patients who underwent gracilis muscle wrapping around the perineally transposed antropyloric valve in an attempt to improve voluntary fecal control.

SETTING

This study was conducted at a single tertiary care institution.

PATIENTS

Eight adult patients (7 men and 1 woman) with a median age of 38 years (range, 19-51 years) underwent this procedure. Seven patients already had anorectal reconstruction with a transposed antropyloric valve, and 1 patient with severely damaged anal sphincter complex underwent single-stage composite antropylorus transposition with a gracilis muscle wrap.

MAIN OUTCOME MEASURES

The primary outcome measures were anatomical integrity and functional status of the composite graft in the perineum.

RESULTS

No operative mortality or serious procedure-related morbidity occurred in any patient. The median postoperative resting pressure was 29 mmHg (range, 22-38 mmHg) and squeeze pressure was 72.5 mmHg (range, 45-267 mmHg). There was a significant improvement in the squeeze pressure following surgery (p = 0.039). Also, the St. Mark's incontinence scores significantly improved in all patients and varied between 7 and 9 (p = 0.003). The ability to defer defecation and the reduced frequency of leakage accidents were the prime reasons for improved postgraciloplasty outcomes in these patients. On personal interviews, all patients who underwent this procedure were satisfied with the results of their surgery.

LIMITATIONS

A longer follow-up with a larger sample size is required. Quality-of-life data have not been evaluated in this study.

CONCLUSIONS

Gracilis muscle wrapping around a perineally transposed antropyloric valve is possible and improves the voluntary control and overall functional outcomes in a select group of patients with end-stage fecal incontinence requiring anal replacement (Supplemental Digital Content 1, http://links.lww.com/DCR/A173).

Neuromodulation of perineally transposed antropylorus with pudendal nerve anastomosis following total anorectal reconstruction in humans

BACKGROUND

We have reported perineal antropyloric segment transposition with its pudendal innervation as a replacement for anal sphincter. Our aim herein was to neuromodulate this segment by electrical stimulation.

METHODS

Eight patients with a permanent colostomy underwent perineal antropyloric segment transposition followed by neural anastomosis of its anterior vagus branch to pudendal nerve branch in the perineum. Perineal antropyloric graft was assessed for its functional integrity and electrophysiological effects. Nerve stimulation was done by surface stimulation technique, using a customized stimulation protocol for smooth muscle. Antral pressures were recorded on voluntary attempts and on nerve stimulation with simultaneous concentric needle electromyography of the perineal antropylorus.

KEY RESULTS

The antral segment showed slow spontaneous contractions (2-3/min) on digital examination, endoscopy, and electrophysiology. Stimulated antropyloric electromyography showed a latency of 2-5 s with a differential rise in amplitude (mean range 58.57-998.75 μV) according to the frequency of stimulation (range 10-150 Hz). An average latency of 10 s in relation to rise in the antral pressure was observed on pudendal nerve stimulation. Triggering of the intrinsic rhythm was observed in patients where it was initially absent. Voluntary attempts at contraction also showed a rise in perineally transposed antral pressure.

CONCLUSIONS & INFERENCES

Spontaneous rhythm, its generation after electrical stimulation, and response to voluntary contraction demonstrates the viability and functional reinnervation of the perineally transposed antropyloric segment. Rise in pressure on electrical stimulation shows evidence for its neuromodulation.