Presentation Authors: Tara Morgan*, Natalie Pace, Anand Mohapatra, Dianxu Ren, Aisha Taylor, Christopher Chermansky, Pittsburgh, PA
Introduction: Refractory overactive bladder (OAB) has detrimental effects on quality of life, and patients often exhaust non-surgical treatment options with minimal improvement in their symptoms. Sacral neuromodulation (InterStimÂ®) is a third line, FDA approved therapy for refractory OAB. We evaluated clinical and procedural characteristics of InterStimÂ® that predict short-term and long-term efficacy.
Methods: A retrospective chart review was performed on patients who underwent a staged InterstimÂ® procedure between January 1, 2007 and January 1, 2018. The clinical and procedural characteristics we evaluated included BMI, comorbidities, age, intraoperative motor responses, and operative time. Endpoints included completed Stage 2 InterstimÂ® procedure, InterstimÂ® lead revision, and patient reported clinical responses at various timepoints. Using SAS 9.4, we statistically determined the mean and standard deviation for continuous variables and the frequency and percentage for categorical variables. The Mann-Whitney U test was used to compare mean differences. The Chi-square test was used to compare the percentage differences between two groups.
Results: We performed a retrospective analysis of 142 female subjects with a mean age of 62.9 years (SD +/-14.2). Mean operative time for stage 1 was 73.6 minutes (SD +/- 20.7), and 75% had prior pelvic surgery. The mean BMI was 31 (SD +/- 7.62). A total of 91.4% of patients went onto Stage 2 InterstimÂ®, and 82% of these patients reported success at their first postoperative appointment. Furthermore, 75% reported continued success at their 3-6 month follow-up. Yet, 24% required InterstimÂ® lead revision for either lack of efficacy, pain, and/or infection. Intraoperative motor responses were analyzed, and patients were divided into either group 1 (anal bellows and great toe dorsiflexion in either 1, 2, or 3 electrodes) or group 2 (anal bellows and great toe dorsiflexion in all 4 electrodes). There was no statistically significant difference between these 2 groups in the rates of patients that went onto complete Stage 2 InterstimÂ®, self-reported success, or required lead revision.
Conclusions: There is limited literature on what characteristics predict patient success or failure with InterstimÂ® therapy. The total number of electrode responses during intraoperative testing did not impact either short or long-term InterstimÂ® success.