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

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.