EP385 - Sacral Neurostimulation for Treatment of Fecal Incontinence After IPAA: A Propensity Matched Cohort Analysis of Outcomes

Purpose/Background: Patients with ileal-pouch anal anastomosis (IPAA) with postoperative fecal incontinence (FI) have limited treatment options (e.g. lifestyle modification and pelvic floor physical therapy) to improve function. Sacral neurostimulation (SNS) is well established as a treatment for refractory FI, but this has not been studied well in patients with IPAA. We aimed to review our institutional experience in SNS for FI in patients with IPAA and compare SNS outcomes to control patients without IPAA in a matched cohort study. We hypothesized that SNS placement for FI in IPAA would lead to improved post-SNS Wexner scores.

Methods/Interventions: We performed a retrospective review of patients with IPAA from a prospectively maintained database for patients who underwent SNS placement for FI after IPAA. Patients who underwent SNS for urinary incontinence were excluded. Demographics, operative details, diagnostics, and outcomes were collected. Quality of life was calculated from prospectively maintained ileal pouch survey data utilizing symptom, health, and energy Likert scores. Statistical analysis of paired continuous outcomes was performed with Wilcoxon signed-rank test. Propensity score matching was performed to a control population of fecal incontinence patients with SNS and without IPAA to SNS in IPAA patients in a 5:1 ratio without replacement; matching variables included age, sex, year of SNS placement, and pre-operative Wexner score.

Results/Outcomes: A total of 15 patients who underwent SNS placement for FI after IPAA were included. Median age was 63 (49-68) years old; 60% of patients were female (9/15), and median BMI was 24.2 kg/m2 (20.9-27.2). IPAA diagnosis was ulcerative colitis (UC) in 80%, familial adenomatous polyposis in 6.7%, and other indications in 13.4%; of UC patients, 20% had phenotypic switching from UC to Crohn's disease. Of note, 46.7% of patients had a history of pouch revision before SNS placement (7/15): six patients with neo-IPAA and handsewn anastomosis, and one patient with pouch repair. Median SNS follow-up was 164.5 months (64 - 238). Pre- and post-SNS outcomes in IPAA patients are shown in Table 1. Post-SNS, median Wexner score decreased from 19 to 14 (13 - 17), with median Δ of -5 (95% CI -7.5 to -3, p=0.002). Post-SNS median leaks per week were reduced from 15 to 4 (2-8), with median Δ -11.5 (95% CI -19 to -6.5, p=0.001). Post-SNS, median BM/24 h decreased from 14 to 7.5 (6.25-10), with median Δ -5.5 (95% CI -7.5 to -3, p=0.003). After matching to controls, pre-/post-SNS Wexner score and pre-/post-SNS leaks per week were compared (Table 2). Overall, the SNS failure rate was 22.2% and was not significantly different between controls and IPAA patients (20% vs. 33%, p=0.29). Control patients had a better improvement in their post-SNS Wexner score than IPAA patients, with an absolute median Δ 4.8 (95% CI 2.8-7.4, p=0.002). Reduction in leaks per week was similar between IPAA and control patients (p=0.17).

Conclusion/Discussion: Sacral neurostimulation is safe and effective in treating fecal incontinence in IPAA patients, with significant reductions in Wexner score, leaks per week, and BM frequency. Outcomes of SNS were overall comparable to control patients without IPAA. Larger, prospective studies are needed and underway to validate efficacy.

Table 1. Outcomes in IPAA patients before and after SNS placement (N=15).
Table 1 Legend. Figures represent median (interquartile range). SNS = sacral neurostimulator, IPAA = ileal pouch-anal anastomosis, IQR = interquartile range, Δ = delta difference, CI = confidence interval, BM = bowel movements, FI = fecal incontinence, CCF QOL = Cleveland Clinic Global Pouch Quality of Life (calculated using quality of life, health, and energy scores as a percentage). (1) Statistical analysis of paired outcomes done with Wilcoxon signed-rank test, p<0.05 considered statistically significant.
Table 2. Outcomes of SNS placement for fecal incontinence in patients with IPAA (N=15) versus matched control patients without IPAA (N=75)
Table 2 Legend. Figures represent median (interquartile range) or N (frequency). SNS = sacral neurostimulator, IPAA = ileal pouch-anal anastomosis, Δ = absolute (median difference), CI = confidence interval. Statistical analysis of outcomes done with (1) Wilcoxon signed-rank test for paired continuous outcomes, and (2) conditional logistic regression for categorical outcomes, p<0.05 considered statistically significant.