PD38-01: Feasibility, safety and efficacy results of the SUFU Foundation open label clinical trial of ultrasound confirmed transvaginal botulinum toxin A (BTA) for refractory overactive bladder (OAB)

Sean W. Berquist*, Stanford, CA, Chen Shenhar, Tikva, Israel, Stefanie van Uem, Ashu Mohammad, Abdelrahman S. Abdalla, Craig V. Comiter, Stanford, CA, Raveen Syan, Miami, FL, Eboo Versi, New Brunswick, NJ, Amy D. Dobberfuhl, Stanford, CA

Introduction: To address challenges associated with delivering botulinum toxin A (BTA) via traditional cystoscopy for refractory overactive bladder (OAB), the SUFU Foundation sponsored a pilot clinical trial to determine feasibility, safety and efficacy of transvaginal intradetrusor BTA.

Methods: Women with refractory OAB were prospectively enrolled (March 2019 to June 2021) and underwent transvaginal ultrasound to confirm anatomy of the trigone and bladder. Ultrasound was removed and transvaginal intradetrusor BTA injection (Botox® 100 units) was performed under direct visualization via half speculum. Repeat ultrasound was performed to confirm correct delivery of BTA. Prospective feasibility, safety and efficacy outcomes were recorded. Treatment benefit scale (TBS) and patient global impression of change (PGIC) were recorded at 6 and 12 weeks. After 12 weeks subjects were eligible for the continuity phase and repeat BTA injection at time of symptom recurrence (PGIC <50% improved) to determine inter-injection interval duration of effect. Covariates were recorded at each study visit: AUASS, OABq-SF SB & QOL, 3-day bladder diary. Data are presented as mean ± SD, and analyzed in SAS by repeated measure ANOVA.

Results: Women (n = 15, age 67±8 yr, BMI 27.5± 5.2, medical comorbidities 4.5 ± 2.6) underwent a total of 31 BTA injections, and were previously treated with 1.8 ±0.9 1st/2nd line, and 0.7 ± 0.9 3rd line OAB treatments. Feasibility was demonstrated by all subjects completing BTA injection [procedure pain score 2.5 ± 1.6 (0-10 scale)]. Ultrasound confirmed correct BTA delivery in all subjects. Safety was demonstrated by 0% immediate procedural complication, 0% rate of retention and 3% rate of UTI. Prior to 12 week follow-up, 2 subjects were lost, and 1 died of unrelated causes. 75% of subjects reported significant improvement at 6 weeks and 58% reported improvement at 12 weeks. There was significant improvement in AUASS, OAB-qSF SB & QOL total scores on ANOVA [F(1,11) = 5.02, p = 0.04; F(1,11) = 7.14, p = 0.02 & F(1,11) = 8.4, p = 0.01]. Mean void volume on diary significantly increased by 6 weeks [F(1,10) = 6.2, p = 0.03]. Eligible subjects were enrolled in the continuity phase and demonstrated an inter-injection interval of 18.9 ± 9.6 weeks.

Conclusions: Transvaginal BTA for refractory OAB appears to be a simple, feasible, safe, and efficacious procedure, with a mean inter-injection duration of effect greater than 18 weeks, when administered in an open label clinical trial.

Source of Funding: SUFU Foundation