The effects of botulinum toxin injection on urodynamic changes in pediatric population with neurospastic bladder: First trial in Iran.

[BACKGROUND] Neurogenic bladder is one of the serious, disturbing problems referred to pediatric urologic clinics. The increase in bladder pressure may damage the upper urinary tract. Anticholinergic medications have been used as the first line of complementary treatment. Regardless can be omitted, botulinum toxin (BT) was introduced as an alternative method for increasing bladder compliance. BT is a neurotoxic poison that can interfere with acetylcholine release, leading to reduced external sphincter pressure and detrusor activity. This study was established to assess urodynamic changes following BT injection among Iranian pediatric population, for the first time.

[METHODS] This clinical trial was conducted at Shahid Beheshti University of Medical Sciences (SBUM), Tehran, Iran, from November 2018 to January 2019 as a medical graduation dissertation. Twenty patients, previously as followings with a neurogenic bladder who met the eligibility criteria, underwent BT injection with general anesthesia using a rigid cystoscope and an endoscopic needle. Demographic data, history of anticholinergic consumption, side effects or intolerance, and the dosage of the injected BT were all recorded. The urodynamic variables during our study included: flow rate in second two, the flow time of diuresis, time of peak flow, average flow, discharged volume, maximum detrusor muscle filling pressure, maximum flow, acceleration, post-void residual volume, compliance, and cystometric bladder capacity. SPSS software version 22 was used to analyze data. The significance level was considered less than 0.05.

[RESULTS] Twenty patients who did not respond to anticholinergic medications or could not tolerate the side effects were entered the study. The mean age was 7.7 ± 2.02 years (range 5-13), and 13 (65%) of them were male. All patients received anticholinergic medications before BT injection. Discharge volume and maximum detrusor muscle filling pressure showed the most significant changes after injection (p < 0.005). However, there was no significant effect of the baseline characteristics on post-injection improvement in urodynamic results (p > 0.05).

[CONCLUSION] In this study, maximum detrusor filling pressure and discharge volume were both significantly improved. These findings motivate additional studies towards selecting better indexes for defining the clinical improvement and its relation with specific urodynamic results.

[LEVEL OF EVIDENCE] Treatment study, level III.