Intravesical botulinum toxin a injections do not benefit patients with ulcer type interstitial cystitis

Abstract

Background: Ulcer type and non-ulcer type interstitial cystitis/bladder pain syndromes (IC/BPS) are considered different disease entities. Thus, intravesical botulinum toxin A (BoNT-A) treatment outcomes could differ for each entity. Objectives: To evaluate and compare the treatment outcomes of BoNT-A injections for treatment of each IC/BPS type. Study Design: Prospective interventional study. Setting: Tertiary medical center affiliated with Buddhist Tzu Chi General Hospital and Tzu Chi University, Taiwan. Methods: Forty-four consecutive patients with IC/BPS for whom conventional treatments failed were prospectively enrolled in this study. Patients were classified as having ulcer (n = 10) or non-ulcer (n = 30) IC/BPS based on their previous cystoscopic findings. Intervention: All patients received 4 sets of intravesical BoNT-A injections (100 U in 40 suburothelial injections) every 6 months. The primary end-point was the global response assessment (GRA) 6 months after the fourth set of BoNT-A injections. Secondary end-points included the O'Leary-Sant score (OSS) including symptom indexes (ICSI) and problem indexes (ICPI), visual analog scale (VAS) pain score, voiding diary, and urodynamics variables. Results: After 4 sets of BoNT-A injections, 15 patients with non-ulcer IC/BPS had GRA scores ≥ 2, while the other 15 had GRA scores < 2. All 10 patients with ulcer IC/BPS had GRA scores < 2 at the study end-point (treatment failure). At baseline, patients with ulcer IC/BPS had significantly higher daytime frequency, nocturia, smaller functional bladder capacity, smaller voided volume, greater VAS, smaller maximal bladder capacity, and greater glomerulation grade than did patients with non-ulcer IC/BPS. After 4 sets of BoNT-A injections, patients with non-ulcer IC/BPS and GRA scores ≥ 2 or < 2 all had significantly decreased ICSI, ICPI, OSS, VAS pain scores, frequency episodes, and increased functional bladder capacity. However, patients with ulcer IC/BPS showed no significant change in any clinical or urodynamic variable. After failure of repeated BoNT-A injections, all 10 patients with ulcer IC/ BPS underwent transurethral electrocauterization of their ulcers, which resulted in immediate pain relief. Limitations: Lack of a control arm in this study. Conclusion: Repeated intravesical BoNT-A injections provided effective treatment outcomes at the end-point in half of the patients with non-ulcer IC/BPS, but did not benefit any patient with ulcer type IC/BPS. Ulcer type IC/BPS should be treated as a different disease than non-ulcer IC/BPS.