45: The first injection: Rates of urinary retention in women with urgency incontinence treated with intravesical onabotulinumtoxinA (Botox) injection

Abstract

To describe rate and risks for symptomatic and asymptomatic urinary retention requiring catheterization in women undergoing initial intravesical onabotulinumtoxinA (Botox) injection for urgency urinary incontinence (UUI). This was a retrospective chart review of women receiving their first 100 unit Botox injection for idiopathic UUI over 5-years. All patients had straight-catheterized post-void residual (PVR) done 2-weeks after injection. Based on symptoms and PVR patients were divided into “retention” and “non-retention” groups. The “retention” group was further divided into asymptomatic patients with a PVR greater than 300 mL or symptomatic patients with a PVR greater than 150 mL. Symptoms of retention included a sensation of incomplete bladder emptying, worsened urgency or frequency, difficulty/inability to void, or suprapubic pain. Continuous variables were compared using student t tests and categorical variables using χ2 tests. 187 patients with mean age of 65 ± 12 years and BMI of 29.7 ± 7.5kg/m2 were included. Majority was postmenopausal (89%) and white (82%). 69 underwent urodynamic testing (UDS) with 50% demonstrating DO. Mean baseline PVR was 27±30 ml. 163 patients (87%) followed up at 2-weeks. 17 (10%) had retention requiring catheterization: 4 were asymptomatic (PVR >300 mL) and 13 were symptomatic (9 with PVR >150 and <300ml and 4 with PVR >300 ml. Most (13 patients) elected to manage retention with intermittent straight catheterization and 1 with Foley. Three declined to have any catheterization. 20% had a symptomatic, culture-proven UTI in the first month after injection: 35% with and 19% without retention (p=0.09). There were no differences in maximum cystometric capacity (359±150 ml vs 321±105 ml, p= 0.64, baseline PVR (25±27ml vs 46±52 ml, p=0.12) or presence of DO (57% vs 29%, p = 0.16) in women with and without retention. Age (p=0.58), menopausal status (p=1.0), diabetes (p=1.0), and smoking (p=0.16) were not associated with retention. However, women who had previous anti-SUI procedures were more likely to experience retention (53% vs 18%, p = 0.002) even though they did not have higher baseline PVRs (32 vs 26ml, p=0.3). One in 10 women experienced clinically significant urinary retention within 2-weeks of initial Botox for UUI. Nearly all (98%) were symptomatic suggesting that routine PVR follow-up is unnecessary.