Videourodynamic factors predictive of successful onabotulinumtoxinA urethral sphincter injection for neurogenic or non‐neurogenic detrusor underactivity

Objective The aim of the present study was to analyze treatment outcomes and identify videourodynamic factors predictive of successful urethral onabotulinumtoxinA treatment of neurogenic and non‐neurogenic detrusor underactivity (DU). Methods Patients with DU refractory to medical treatment were treated with injections totaling 100 U onabotulinumtoxinA into the urethral sphincter. Treatment outcomes were assessed 1 month after treatment using the Global Response Assessment. The videourodynamic parameters evaluated included bladder neck status during voiding, bladder sensation, detrusor pressure, maximum flow rate, and post‐void residual volume. Treatment outcome was analyzed by patient and baseline videourodynamic characteristics. Results In all, 60 patients (27 with non‐neurogenic and 33 with neurogenic DU) were included in the study and received urethral sphincter injections of 100 U onabotulinumtoxinA in total. Good outcomes were reported in 36 (60%) patients (20 [74.1%] with non‐neurogenic and 16 [48.5%] with neurogenic DU). Treatment outcome was significantly better in patients with non‐neurogenic than neurogenic DU (P = .039). However, good treatment outcome was not related to age, gender, or any videourodynamic variables, except for an open bladder neck during voiding vs non‐opening bladder neck (94.3% vs. 12.0%; P