title: Increased risk of large post-void residual urine and decreased long-term success rate after intravesical onabotulinumtoxinA injection for refractory idiopathic detrusor overactivity.
abstract: OBJECTIVE
  Intravesical injection of onabotulinumtoxinA is effective for idiopathic detrusor overactivity refractory to antimuscarinics. However, safety is a major concern, especially in elderly individuals. We investigated the efficacy and safety of intravesical onabotulinumtoxinA injection for refractory idiopathic detrusor overactivity in the frail elderly population.
  
  
  METHODS
  A total of 166 patients with urodynamic idiopathic detrusor overactivity refractory to previous antimuscarinics for more than 3 months received 1 intravesical 100 U onabotulinumtoxinA injection from 2004 to 2009. Frail elderly was defined as age greater than 65 years and 3 or more of certain criteria, including unintentional weight loss, self-reported exhaustion, weakness, slow walking speed and/or low physical activity. Treatment results were assessed by the Patient Perception of Bladder Condition, voiding diary, urodynamic parameters and Kaplan-Meier estimates of survival plots.
  
  
  RESULTS
  We evaluated 61 frail elderly patients, 63 who were elderly without frailty and 42 younger than 65 years. Large post-void residual urine volume (greater than 150 ml) after onabotulinumtoxinA injection was significantly higher in the frail elderly group than in the other groups (60.7% vs 39.7% and 35.7%, respectively, p = 0.018). Urinary retention developed in 7 frail elderly patients (11.5%), 4 (6.3%) who were elderly without frailty and 1 younger patient (2.4%) (p = 0.203). Recovery duration was significantly longer in frail elderly patients. The cumulative success rate was significantly lower in the frail elderly group than in the other 2 groups (p = 0.009).
  
  
  CONCLUSIONS
  Although safety and efficacy were similar between elderly patients without frailty and younger patients, an increased risk of large post-void residual urine volume and a lower long-term success rate in frail elderly patients were noted after intravesical onabotulinumtoxinA injection for refractory idiopathic detrusor overactivity.
authors.affiliation: Department of Urology, Cardinal Tien Hospital and School of Medicine, Fu-Jen Catholic University, Buddhist Tzu Chi General Hospital (HCK) and Tzu Chi University (HCK), Hualien, Taiwan, Republic of China.
authors.forename: Chun-Hou
authors.initials: CH
authors.lastname: Liao
authors.forename: Hann-Chorng
authors.initials: HC
authors.lastname: Kuo
mesh_terms: D000283:Administration, Intravesical; D000328:Adult; D000368:Aged; D019274:Botulinum Toxins, Type A / Q000008:administration & dosage / Q000009:adverse effects*; D005260:Female; D016330:Frail Elderly; D006801:Humans; D008297:Male; D008875:Middle Aged; D018570:Risk Assessment; D013997:Time Factors; D016896:Treatment Outcome; D053201:Urinary Bladder, Overactive / Q000188:drug therapy*; D016055:Urinary Retention / Q000139:chemically induced* / Q000453:epidemiology
chemical_list: D019274:Botulinum Toxins, Type A