Intravesical Onabotulinum Toxin A Injection Paradigms for Idiopathic Overactive Bladder: A Scoping Review of Clinical Outcomes, Techniques, and Implications for Practice and Future Research.

Introduction And Objectives: Onabotulinum toxin A (BTXA) is an effective treatment for refractory idiopathic overactive bladder (iOAB). Given the wide spectrum of patient factors and combination of symptoms, a tailored approach to management is needed. This scoping review assesses injection paradigms for iOAB. Prior studies have established the safety and efficacy of BTXA injections, and this review focuses on exploring variations in injection techniques that may inform more tailored approaches and support future research toward optimizing patient outcomes.

Methods: We conducted a systematic literature search. Inclusion criteria included full-text English language and primary research studies assessing outcomes in adults undergoing BTXA for iOAB. Findings are summarized using narrative synthesis.

Results: Forty-three articles were identified. Key findings include fewer injections (1-10 vs. 20-40) maintains efficacy while reducing procedure time, discomfort, and retreatment hesitancy. Durability appears to be lower with suburothelial and bladder base injections and higher with detrusor and bladder body injections, though these may carry an increased risk of urinary retention requiring clean intermittent catheterization. Trigone inclusion appears safe and effective without increased vesicoureteral reflux risk.

Conclusions: Study heterogeneity and inconsistent reporting limit strong conclusions. Included injection paradigms demonstrated efficacy, high tolerability, symptom relief, and quality-of-life improvements with few adverse events. Further research is needed to refine optimal injection strategies to enhance patient comfort, maximize efficacy, and minimize adverse events. Future studies should ensure comprehensive data collection to clarify these associations.