The Magnetic Anal Sphincter Versus the Artificial Bowel Sphincter: a Comparison of 2 Treatments for Fecal Incontinence

Abstract

Fecal incontinence is a debilitating ailment, and surgery offers the only recourse for the patients in whom conservative treatment fails. This study aims to report the first matched comparison between patients implanted with the magnetic anal sphincter and the artificial bowel sphincter. From December 2008 to June 2010, 10 female patients, median age 64.5 years (range, 42-76), with severe fecal incontinence for a median of 7.5 years (range, 1-40), were implanted with the magnetic anal sphincter. Ten female patients implanted with the artificial bowel sphincter were identified. Both groups were matched for age, etiology, duration of incontinence, and preoperative functional scores. Outcomes measures included length of hospitalization, complications, and changes in functional scores (anorectal physiology, incontinence, and quality of life). Patients with the magnetic anal sphincter had a shorter median operative time (62 vs 97.5 min, P = .0273), length of hospitalization(4.5 vs 10 days, P < .001), and follow-up duration (8 vs 22.5 mo, P = .0068), without a statistically significant difference in 30-day complications (4 vs 2, P = .628) and revision/explantation (1 vs 4, P = .830). Both groups achieved significant improvements in preoperative incontinence (P < .0002) and quality-of-life scores (P < .009). In a comparison of baseline resting anal pressures, patients with the artificial bowel sphincter had significantly higher pressures with the cuff inflated (P = .0082), and those with the magnetic anal sphincter had a significant increase as well (P = .0469). At the latest review, both groups had similar quality-of-life scores (P = .374); patients with the artificial bowel sphincter had higher (median) closed-cuff anal pressures compared with the anal resting pressure of those with a magnetic anal sphincter (89 vs 58.5 cmH2O, P = .0147), together with more constipation (4 vs 1, P = .830) and a trend toward better incontinence scores (P = .0625). This was a nonrandomized study with small patient numbers. In the short term, the magnetic anal sphincter is as effective as the artificial bowel sphincter in restoring continence and quality of life.