Efficacy of Sacral Neuromodulation in Treatment of Fecal Incontinence Associated With Anal Sphincter Defects: A Systematic Review and Meta-Analysis.

Abstract

Anal sphincteroplasty (AS) was considered standard treatment for fecal incontinence (FI) associated with sphincter injury; however, long-term outcomes have been disappointing. Sacral neuromodulation (SNM) has proven effective for FI secondary to anal sphincter defects. This review aimed to assess outcomes of SNM in FI associated with anal sphincter defects and to compare outcomes to AS. A PRISMA-compliant systematic review inquired PubMed and Scopus through January 2025 for studies that assessed SNM in FI secondary to anal sphincter defects. The primary outcome was continence improvement and change in baseline incontinence scores; overall complications were the secondary outcome. Random-effect meta-analyses were used to calculate pooled outcomes and odds of continence improvement after SNM compared to AS. Ten studies incorporating 779 patients (93.9% female; median age 54.5 years) were included. SNM was performed in 503 (64.5%) and AS in 265 (34%) patients. The weighted mean reduction in incontinence scores after SNM was 8.53 points (95% CI: 6.11, 10.96, p < 0.001) and the pooled rate of continence improvement was 66.7% (95% CI: 52.2%-81.1%). Previous sphincteroplasty, external sphincter defects > 120°, and low resting anal pressure were significantly associated with less continence improvement. Pooled complication and device removal rates were 18.5% (95% CI: 8.7%-28.2%) and 9.1% (95% CI: 3.4%-14.7%), respectively. SNM was associated with better continence improvement than AS (OR: 1.68, p = 0.006) with similar odds of complications (OR: 0.73, p = 0.763). SNM was associated with a good improvement in FI associated with anal sphincter defects. However, a longer follow-up is required to ascertain these mid-term outcomes. There are not enough data to date to draw solid conclusions regarding the comparison between SNM and sphincteroplasty in patients with sphincter lesions.