Improving clinical outcomes with lower motor voltage (≤3 V) during stage 1 sacral neuromodulation for interstitial...

We desire to evaluate whether utilization of ≤3 V (new experimental approach) vs the traditional four or more volts for lead motor response during stage 1 sacral neuromodulation may impart an improvement in voiding and pain parameters.

An observational, retrospective, double cohort review was conducted of 179 female patients who experienced medically recalcitrant interstitial cystitis (IC) or bladder pain syndrome (BPS) between January 2002 and January 2013. Group A included 105 women with a motor response of ≤3 V; group B was comprised of 65 women with a motor response at ≥4 V for medically recalcitrant IC or BPS. Patients completed a 3-day pre- and postoperative voiding diary, visual analog pain (VAP) scale, pain urgency frequency (PUF), and Patient Global Impression of Improvement (PGI-I) questionnaire.

The mean (standard deviation) follow-up in months was 120.1 ± 33.3 in group A and 116.3 ± 29.2 in group B (P < .45). A successful conversion from stage 1 to stage 2 showed statistically significant improvement for group A compared with group B (95.4% vs 73.8% conversion rate; P < .001). The success rate also favored group A, with 87.6% success compared with 66.2% for group B (P < .002). Group A mean postoperative VAP scores improved over group B with 3.3 ± 1.2 compared with 5.0 ± 0.8 (P < .001). Group A mean postoperative PUF scores were 10.2 ± 2.7 and group B 14.7 ± 3.5, (P < .001).

In the ≤3 V patient cohort, a compelling, significant statistical improvement was noted in most clinical voiding parameters, including the VAP, PGI-I, and performance questionnaires.