Intravesical botulinum (BoNT) toxin is a safe and effective treatment option for patients with refractory overactive bladder and neurogenic lower urinary tract dysfunction (1, 2). A previous survey identified that most Canadian urologists use intravesical instillation of lidocaine solution prior to BoNT for pain control (3). However, this requires an additional catheterization for the patient, extra time and nursing resources, and may be a barrier to treatment delivery for some providers. Furthermore, there is a lack of evidence suggesting superior pain control with use of intravesical lidocaine solution in this context. This is a clinical, non-surgical cohort study designed to compare pain scores in patients undergoing BoNT using intravesical lidocaine instillation and lidocaine gel vs lidocaine gel alone. Secondary objectives are: 1) to compare pain scores between patient subgroups (sex, indication for treatment, and first vs subsequent treatment), 2) to compare post-procedural complications, and 3) to compare the number of treatment failure.

All patients undergoing BoNT between March 1st and September 1st, 2022, were included. Patients receiving BoNT before June 1st, 2022, received intravesical lidocaine solution (20 ml 2% lidocaine solution + 30 ml 0.9% normal saline) instillation for 30 minutes and lidocaine gel (Instillagel) prior to BoNT for pain control (Group 1).  Patients receiving treatment on or after June 1st, 2022, received lidocaine gel (Instillagel) only immediately before BoNT (Group 2). In addition, in Group 1 a rigid cystoscope was used for female patients and a flexible scope for male patients whereas in Group 2 a flexible scope was used for both female and male patients. Patients were excluded if they had impaired sensation to the bladder (eg. secondary to a previous neurologic injury). The Visual Analogue Pain Score (VAS) was used to measure patient reported pain immediately following treatment. Baseline demographics, indication for treatment (overactive bladder vs neurogenic bladder vs other), post-procedural complications, and treatment failure were collected prospectively. Treatment failure was defined as a patient who did not tolerate treatment or requested that future treatments be performed under sedation. Patient demographics and clinical variables were compared using basic descriptive analysis with t-test for continuous and chi-square for categorical variables. The Mann-Whitney U Test was used to compare overall pain scores between treatment groups as well as pain scores between patient subgroups. Sample size was calculated at least 34 in each group by assuming difference in medians of 1.5, standard deviation of 2, alpha of 0.05 and beta 0.80. All statistical analysis was performed SAS version 9.4.

A total of 80 patients were included (mean age 61 years, 75% female, 56% with overactive bladder, and 30% receiving first treatment). Thirty-nine patients (49%) were included in Group 1 compared to 41 (51%) in Group 2.  There were no significant differences in baseline characteristics between treatment groups (p > 0.05).  There was no significant difference in pain scores between groups: Group 1 median VAS 3.0 (Q1 2.5, Q3 5.0) vs Group 2 median VAS 4.0 (Q1 3.0, Q3 5.0); p = 0.11. Furthermore, there were no significant differences in pain scores between groups based on sex, indication for treatment, or whether patients were receiving their first or subsequent BoNT treatments (p>0.05). Post-procedural complications occurred in four patients in Group 1 (three UTI, one Hematuria) compared to two patients in Group 2 (two UTI). Treatment failure did not occur in any patients in either group.

The use of lidocaine gel alone immediately before BoNT provided comparable pain control to traditional intravesical instillation of lidocaine solution regardless of sex, treatment indication and number of treatments received. There were no treatment failures and post-procedural complications were low in both groups.

The use of lidocaine gel alone may be an acceptable analgesia alternative to intravesical lidocaine solution instillation while improving efficiency and availability of treatment. Further randomized studies are required to identify optimal analgesia regimens for this procedure.

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Cruz F, Herschorn S, Aliotta P, Brin M, Thompson C, Lam W, Daniell G, Heesakkers J, Haag-Molkenteller C. Efficacy and safety of onabotulinumtoxinA in patients with urinary incontinence due to neurogenic detrusor overactivity: a randomised, double-blind, placebo-controlled trial. Eur Urol. 2011 Oct;60(4):742-50. doi: 10.1016/j.eururo.2011.07.002. Epub 2011 Jul 13. PMID: 21798658.
Ross, J., Hickling, D., Maciejewski, C., Coriaty , R., & Vigil, H. (2022). Intravesical botulinum toxin: Practice patterns from a survey of Canadian urologists. Canadian Urological Association Journal, 17(1), E15–22. https://doi.org/10.5489/cuaj.7886