title: Urodynamic assessment of poor responders after botulinum toxin-A treatment for overactive bladder.
abstract: OBJECTIVE
  Botulinum toxin-A (BTX-A) is effective in treating overactive bladder (OAB) refractory to anticholinergics. Most patients have improvements in symptoms, urodynamic parameters, and quality of life, and a poor response is uncommon. The aim of this study was to determine whether poor responders could be predicted from preoperative urodynamic parameters.
  
  
  METHODS
  Data were collected prospectively from 33 OAB patients with idiopathic detrusor overactivity. All patients underwent intradetrusor injections of 200 U BTX-A. Response to treatment was assessed by patient perception, OAB symptoms, and quality of life data. Urodynamics were conducted at baseline and 4, 12, and 24 weeks postinjection. We performed statistical analysis using the Wilcoxon matched pairs, Mann-Whitney, two-sample, and paired t-tests. Receiver operator characteristic (ROC) curves were plotted for relevant parameters.
  
  
  RESULTS
  Five patients had a poor response to treatment. Significant increases in maximum cystometric capacity (MCC), reflex detrusor volume (RDV), and bladder compliance with decreases in maximum detrusor pressures (MDP) on filling were observed in the responders over 24 weeks. Minimal urodynamic benefit was observed in the poor responders group over the same period. When comparing the two groups, baseline MDP in poor responders was 138.0 +/- 30.7 compared with 74.4 +/- 32.6 in the responders (P = 0.0028). ROC analysis suggested that a pretreatment MDP greater than 110 may have predictive value (AUC, 0.946; sensitivity, 0.86; specificity, 1.0) for a poor response to treatment.
  
  
  CONCLUSIONS
  Very high MDP greater than 110 may predict a poor response to treatment with 200 U of BTX-A. Higher doses may be necessary in these patients.
authors.affiliation: Department of Urology, Guy's Hospital and Kings College London School of Medicine, London, United Kingdom.
authors.forename: Arun
authors.initials: A
authors.lastname: Sahai
authors.forename: Mohammad Shamim
authors.initials: MS
authors.lastname: Khan
authors.forename: Nicolas
authors.initials: N
authors.lastname: Le Gall
authors.forename: Prokar
authors.initials: P
authors.lastname: Dasgupta
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019274:Botulinum Toxins, Type A / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009465:Neuromuscular Agents / Q000627:therapeutic use*; D011446:Prospective Studies; D053201:Urinary Bladder, Overactive / Q000188:drug therapy* / Q000503:physiopathology*; D014563:Urodynamics
chemical_list: D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A