Prospective Randomized Evaluation of Periureteral Botulinum Toxin Type A Injection for Ureteral Stent Pain Reduction

Abstract

The use of ureteral stents for ureteral obstruction and after ureteroscopy can result in substantial deterioration in patient quality of life due to pain, frequency and urgency. We postulated that many stent related symptoms may be related to detrusor muscle spasm in and around the intramural ureter, and evaluated the effect of botulinum toxin type A (Botox) in patients with indwelling stents after ureteroscopy. A total of 51 patients between December 2007 and March 2009 were enrolled in an institutional review board approved, prospective, randomized, single-blind study comparing botulinum toxin type A injection at a concentration of 10 U/ml to 3 locations around the ureteral orifice (30) vs no injection after unilateral ureteral stent insertion (21). Pain and urinary symptoms after stent placement were evaluated through the Ureteral Stent Symptom Questionnaire, which was completed on postoperative day 7. In addition, patients were required to maintain a log of narcotic use after stent placement until removal. The Wilcoxon rank sum and Fisher exact tests were used for nonparametric and categorical data, respectively, with p <or=0.05 considered significant. No complications or adverse events occurred in this study. There was a significant decrease in the reported postoperative pain score between the botulinum toxin type A and control group at 3.4 vs 6.0 (p = 0.02). Postoperative narcotic use was also significantly less in the botulinum toxin type A group at 7.7 pills during an average of 2.7 days vs 24.7 in an average of 7.0 days in control patients (p = 0.03). With respect to postoperative lower urinary tract symptoms there was no significant difference between cohorts using the individual index scores within the Ureteral Stent Symptom Questionnaire. Stent related emergency room visits were reported by 1 patient treated in the botulinum toxin type A group vs 2 in the control group. Periureteral botulinum toxin type A injection improves ureteral stent tolerability by significantly decreasing postoperative pain and narcotic requirements. Improvement in irritative symptoms was not observed.