Reduced Injection-Site OnabotA Protocol: Managing Complications

Real-world complication rates with onabotulinumtoxinA (onabotA, Botox) in Steven Bernstein, MD's reduced-site practice have been low across all 3 major categories of concern: bleeding, urinary tract infection (UTI), and urinary retention requiring catheterization. In more than 1000 treatments, a single significant post-procedural bleed was observed, occurring early in Bernstein's experience during the 20-site injection phase; no significant bleeds have occurred since transitioning to reduced-site protocols. A UTI rate of 4.9% per treatment was observed in the retrospective series—a figure Bernstein characterizes as consistent with the baseline prevalence of lower urinary tract symptoms in this patient population rather than a procedure-related increase. A single prophylactic antibiotic tablet is administered with each treatment, and no patient has required hospitalization for infection.

Urinary retention is counseled prospectively in all patients, although Bernstein notes that clinically meaningful retention is uncommon in his reduced-site experience. Notably, his practice does not use a fixed post-void residual (PVR) volume threshold to trigger catheterization; rather, catheterization is recommended only in symptomatic patients. In more than 1000 treatments, only 1 patient was advised to catheterize—a patient with a PVR of 850 mL who declined but returned months later with a residual of 100 mL and requested a subsequent treatment without issue. This symptom-guided management approach, Bernstein observes, distinguishes his protocol from earlier published studies and contributes to a low catheterization rate.

Two additional workflow modifications have simplified the procedural process in Bernstein's practice. First, intravesical lidocaine pretreatment—used in approximately 63% of treatments early in his experience but declining over time—was ultimately discontinued after patients reported no perceptible difference in comfort. Bernstein explains that the primary source of procedural discomfort is the detrusor injection itself rather than mucosal puncture, limiting the mechanistic rationale for intravesical anesthesia; persistence rates were similar regardless of lidocaine use. Second, routine pre-procedure urinalysis was replaced with a single symptom-screening question; only patients reporting dysuria are evaluated further. This change reduced delays and enabled a higher throughput of same-day treatments without an increase in observed infection rates.