Introduction This study aimed to compare outcomes of patients with anal sphincter defects treated by sacral nerve stimulation (SNS) or sphincteroplasty (SP).

Method After IRB approval, patients treated for FI with a sphincter defect were identified from a prospective database; treatment groups were matched and stratified by SNS or SP. Primary outcome was change in Wexner FI Score (FIS). Demographic variables, past medical history and complication rates were also reviewed. Sphincter defects were assessed by endoanal ultrasound and ranged from 45°–180°. Continuous variables were compared with independent t-tests or Mann-Whitney U tests based on evidence of Gaussian distribution. Categorical variables were compared with Chi-squared analyses. Paired within group analyses were performed with paired t-tests and Wilcoxon signed-rank test. In order to perform a paired assessment of the role of each intervention in affecting the FIS, an Analysis of Covariance (ANCOVA) was performed.

Results 26 female patients were included, 13 each underwent sphincteroplasty or SNS. The groups were similar with regards to age (62.2 vs 57.2 years, p = 0.16), BMI (26.2 vs 26.5, p = 0.33), initial FIS (15.9 vs 16.8, p = 0.39) and follow-up (14 vs 10 months, p = 0.72). The groups were similar for >1 vaginal delivery or rates of urinary incontinence (p = 1.00 and p = 0.62, respectively). Early postoperative complications included 1 patient in each group with wound infection. Within group analyses revealed a significant improvement of FIS in SNS patients (15.9 to 8.4; p = 0.003) but not observed in the SP group (16.9 to 12.9; p = 0.078). Between groups, a trend towards lower FIS was seen in the SNS group as compared to SP but was not significant (8.4 vs 12.9; p = 0.06). ANCOVA analysis did reveal either procedure as superior in reducing FIS.

Conclusion This study demonstrates that within each group SNS is effective at reducing FI in patients with a sphincter defect. Larger sample sizes will be required to better compare the difference in scores and assess for superiority between procedures.

Disclosure of interest None Declared.