Sacral nerve stimulation for fecal incontinence related to external sphincter atrophy.
BACKGROUND
Atrophy of the external anal sphincter, a pathologic muscle volume anomaly associated with fecal incontinence, has been shown to be a negative predictor of the outcome of surgery for defects of the external anal sphincter. It is unclear whether external anal sphincter atrophy also affects the outcome of sacral nerve stimulation for fecal incontinence.


OBJECTIVE
Our aim was to assess the effectiveness of sacral nerve stimulation in patients with fecal incontinence and external anal sphincter atrophy and to determine whether severity of atrophy and concomitant presence of a sphincter defect are negative predictors of outcome.


METHODS
This was a prospective observational study of treatment outcome.


METHODS
The study was conducted from November 2004 through November 2010 at a regional hospital in Italy.


METHODS
Consecutive patients with fecal incontinence and external anal sphincter atrophy were included. By means of MRI, patients were determined to have either moderate (<50%) or severe (≥ 50%) thinning of and/or replacement of sphincter muscle by fat. The concomitant presence of defects of the external anal sphincter was also detected by MRI.


METHODS
All patients underwent sacral nerve stimulation through a staged implantation procedure.


METHODS
The main outcome measures were improvement in the Cleveland Clinic Florida Fecal Incontinence Scale (Wexner score), number of episodes of incontinence per week, and the Fecal Incontinence Quality of Life Scale.


RESULTS
A total of 28 patients underwent definitive implantation of the sacral nerve stimulation device. Wexner scores decreased from a median of 16 (range, 10-20) at baseline to 3 (range, 0-8) at 6-month follow-up (p < 0.001). Weekly incontinence episodes decreased from a mean (SD) of 14.7 (12.5) to 0.40 (0.82); p < 0.001. Improvement was significantly related to severity of fecal incontinence (r = 0.86; p < 0.001). Overall quality-of-life scores improved from a mean of 1.8 (0.6) to 3.8 (0.4);p < 0.001. Sacral nerve stimulation was effective in both moderate (n = 16) and severe (n = 12) atrophy and in patients with (n = 8) or without (n = 20) external anal sphincter defects.


CONCLUSIONS
The study was limited by its observational nature and relatively small sample size.


CONCLUSIONS
Sacral nerve stimulation can be effective in restoring continence and improving quality of life in patients with fecal incontinence related to atrophy of the external anal sphincter, regardless of the severity of atrophy. Moreover, the presence of EAS atrophy does not influence the success of the outcome of SNS in patients with a sphincter defect. These findings are consistent with the hypothesis that the effects of SNS are not achieved solely by its action on the anal sphincter complex.
Pelvic Floor Unit, I Department of Surgery, Regional Hospital, Treviso, Italy. giulioasantoro@yahoo.com
Giulio A
GA
Santoro
Aldo
A
Infantino
Luca
L
Cancian
Giuseppe
G
Battistella
Giuseppe
G
Di Falco
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001003:Anal Canal / Q000473:pathology*; D001284:Atrophy / Q000150:complications / Q000175:diagnosis; D005242:Fecal Incontinence / Q000209:etiology / Q000628:therapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011788:Quality of Life; D012447:Sacrum / Q000294:innervation*; D012720:Severity of Illness Index; D004561:Transcutaneous Electric Nerve Stimulation; D016896:Treatment Outcome