Increased risk of large postvoid residual urine and lower long-term success rate in frail elderly after intravesical onabotulinumtoxin A injection for refractory idiopathic detrusor overactivity - Abstract

PURPOSE: Intravesical injection of onabotulinumtoxin A (BoNT-A) is effective for idiopathic detrusor overactivity (IDO) refractory to antimuscarinics.

However, safety is a major concern, especially for the elderly. We investigate the efficacy and safety of intravesical BoNT-A injections for refractory IDO in frail elderly.

MATERIALS AND METHODS: From 2004-2009, 166 patients with urodynamic IDO refractory to previous antimuscarinics for more than 3 months received one intravesical 100U BoNT-A injection. "Frail elderly" was defined as those elder than 65 years with the presence of 3 or more of the following criteria: unintentional weight loss, self-reported exhaustion, weakness, slow walking speed, and low physical activity. Treatment results were assessed using patients' perception of bladder condition (PPBC), voiding diary, urodynamic parameters, and Kaplan-Meier estimates of survival plots.

RESULTS: Subjects were 61 frail elderly, 63 elderly without frailty, and 42 younger than 65 years. Large post-void residual (PVR) volume (>150 mL) after BoNT-A injection was significantly higher in the frail elderly group (60.7%) than in the other groups (39.7% and 35.7%, p=0.018). Urinary retention developed in 7(11.5%) frail elderly, 4(6.3%) elderly without frailty, and 1(2.4%) younger subjects (p=0.203); the duration of recovery was significantly longer in the frail elderly. The cumulative success rate was significantly lower in the frail elderly than in the other 2 groups (p=0.009).

CONCLUSIONS: Although safety and efficacy were similar between elderly without frailty and younger patients, an increased risk of large PVR and lower long-term success rate in frail elderly were noted after intravesical BoNT-A injection for refractory IDO.

Written by:
Liao CH, Kuo HC.   Are you the author?
Department of Urology, Cardinal Tien Hospital and School of Medicine, Fu-Jen Catholic University, Hualien, Taiwan.

Reference: J Urol. 2012 Nov 20. pii: S0022-5347(12)05593-0.
doi: 10.1016/j.juro.2012.11.089

PubMed Abstract
PMID: 23178902 Overactive Bladder (OAB) Section