title: Intravesical prostatic protrusion is better than prostate volume in predicting the outcome of trial without catheter in white men presenting with acute urinary retention: a prospective clinical study.
abstract: OBJECTIVE
  Trial without catheter after a short course of an alpha-blocker in men presenting with acute urinary retention is successful in up to 50% of cases. The ability to better predict outcome could avoid a trial without catheter for some men. Intravesical prostatic protrusion and not prostate volume has been shown to predict trial without catheter outcome in an Asian cohort. We investigated the relationship between the outcome of trial without catheter and prostate volume and intravesical prostatic protrusion in white men given alpha-blockers before a trial without catheter.
  
  
  METHODS
  Consecutive men 50 years old or older presenting with acute urinary retention were prospectively recruited based on strict selection criteria. At presentation factors thought to precipitate acute urinary retention were treated, alpha-blocker therapy started and the patient brought back for a trial without catheter after 2 weeks. Prostate volume and intravesical prostatic protrusion were measured by standard transrectal ultrasonography.
  
  
  RESULTS
  Of 121 men presenting with acute urinary retention 57 fulfilled the study selection criteria. Mean (+/- SD) age, prostate volume and intravesical prostatic protrusion of recruited men were 70 +/- 9.2 years, 69.7 +/- 36.3 ml and 12.8 +/- 10.1 mm, respectively. A total of 25 men (43.9%) had a successful trial without catheter. Mean intravesical prostatic protrusion was significantly smaller in those who had a successful trial without catheter (7.2 vs 16.5 mm, 95% CI 4.5-14, p <0.001). With intravesical prostatic protrusion correlating well with prostate volume (r = 0.588), mean prostate volume was also smaller in men with a successful trial without catheter, albeit with a smaller effect size. Men with an intravesical prostatic protrusion of 10 mm or less, compared to those with a larger intravesical prostatic protrusion, were 6 times more likely to have a successful trial without catheter.
  
  
  CONCLUSIONS
  In this cohort presenting with acute urinary retention related to benign prostatic hyperplasia and receiving alpha-blockers before a trial without catheter, intravesical prostatic protrusion appears to strongly predict the outcome of a trial without catheter. A trial without catheter is more likely to fail in patients with intravesical prostatic protrusion larger than 10 mm.
authors.affiliation: Department of Urology, Western General Hospital, Edinburgh, United Kingdom. param.mariappan@nhs.net
authors.forename: Paramananthan
authors.initials: P
authors.lastname: Mariappan
authors.forename: David J G
authors.initials: DJ
authors.lastname: Brown
authors.forename: Alan S
authors.initials: AS
authors.lastname: McNeill
mesh_terms: D000208:Acute Disease; D000317:Adrenergic alpha-Antagonists / Q000627:therapeutic use*; D000368:Aged; D000369:Aged, 80 and over; D019160:Endosonography / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D011237:Predictive Value of Tests; D011292:Premedication; D011379:Prognosis; D011446:Prospective Studies; D011467:Prostate / Q000000981:diagnostic imaging*; D011470:Prostatic Hyperplasia / Q000000981:diagnostic imaging* / Q000188:drug therapy; D011799:Quinazolines / Q000627:therapeutic use*; D013223:Statistics as Topic; D016896:Treatment Outcome; D001748:Urinary Bladder Neck Obstruction / Q000000981:diagnostic imaging* / Q000188:drug therapy; D014546:Urinary Catheterization; D016055:Urinary Retention / Q000000981:diagnostic imaging*; D014563:Urodynamics / Q000187:drug effects / Q000502:physiology
chemical_list: D000317:Adrenergic alpha-Antagonists; D011799:Quinazolines; C047638:alfuzosin