AT PFD WEEK 2016
DENVER (FRONTLINE MEDICAL NEWS) – Less than 2% of onabotulinumtoxinA injections for idiopathic detrusor overactivity resulted in clean intermittent catheterization, a substantially lower rate than previously found, Juzar Jamnagerwalla, MD, reported at Pelvic Floor Disorder Week.
These included two cases of acute urinary retention and one case in which a patient complained of problems voiding and had a postvoid residual urine volume (PVR) of 353 mL, said Dr. Jamnagerwalla of Cedars-Sinai, Los Angeles. Taken together, the findings suggest that postprocedural PVR can usually be managed safely by observation alone, which may reassure patients who are considering treatment options for overactive bladder, he added.
In a pivotal phase III trial, intravesical onabotulinumtoxinA (Botox) was shown to be safe and effective in treating overactive bladder associated with idiopathic detrusor overactivity, but up to 7% of patients met criteria for clean intermittent catheterization (CIC), with postprocedural PVRs greater than 350 mL, or subjective voiding complaints and PVRs greater than 200 mL ( Eur Urol. 2013 Aug;64:249-56 ).
But these “strict” criteria contrast with real-world practice, in which patients with postprocedural PVR often are observed without CIC unless they have subjective complaints or other contraindications, Dr. Jamnagerwalla said. The discrepancy is especially relevant because patients with overactive bladder who decline onabotulinumtoxinA often cite the risk of CIC as the reason, he added.
To better understand CIC rates at Cedars-Sinai, Dr. Jamnagerwalla and his colleagues reviewed 27 months of records from patients with idiopathic detrusor overactivity who received injections of 100 U of onabotulinumtoxinA given by female pelvic medicine and reconstructive surgery physicians. The patients were followed up immediately and 2 weeks later, but underwent CIC only if they could not void or had PVRs above 350 mL and subjective voiding complaints.
In all, 99 patients received a total of 187 injections, of which only 3 (1.6%) led to urinary retention requiring CIC. The median postprocedure PVR was 117 mL. About three-quarters of patients had PVRs less than 200 mL, 29 (16%) had PVRs between 200 mL and 350 mL, and 13 (7%) had PVRs greater than 350 mL.
Age, body mass index, and preprocedure PVR did not predict urinary retention in the univariate analysis, Dr. Jamnagerwalla said at the meeting, which was sponsored by the American Urogynecologic Society.
The results support the practice of observing patients with elevated PVRs after Botox, as long as they do not develop obstructive symptoms, he advised.
“While it remains important to counsel patients on the risk of urinary retention after Botox injection for idiopathic detrusor overactivity, patients can be reassured that the true rate of retention requiring CIC is relatively low,” he said.
Dr. Jamnagerwalla reported no funding sources and reported having no financial disclosures. Two coauthors reported ties to Boston Scientific, Astora, and Allergan.