title: Effect of radical prostatectomy on urethral blood flow.
abstract: OBJECTIVE
  To study the effect of radical retropubic prostatectomy on urethral microcirculatory blood perfusion and urinary continence. Urinary stress incontinence after radical prostatectomy depends mainly on intrinsic distal sphincter integrity.
  
  
  METHODS
  Urethral laser Doppler flowmetry was performed in 37 patients before and in 23 patients after (mean 15 months, range 2 to 23) radical prostatectomy for clinically localized prostate cancer. An endoscopic laser Doppler flow probe with a diameter of 1.8 mm was introduced through the working channel of a cystoscope and gently applied to the urethral mucosa at an intravesical pressure of 30 cm H(2)O. Blood flow was expressed simultaneously as a digital reading on the flowmeter (milliliters blood per minute per 100 gram tissue). The mean arterial blood pressure was monitored noninvasively. The Mann-Whitney U test was used for statistical analysis.
  
  
  RESULTS
  Membranous urethral blood flow significantly decreased after radical prostatectomy from 18.8 +/- 7.9 mL/min per 100 gram tissue to 11.9 +/- 7.7 mL/min per 100 gram tissue (P = 0.04). However, the difference in the blood flow did not statistically differentiate continent patients from patients with urinary stress incontinence (P = 0.47). No correlation between urethral microcirculation and mean arterial blood pressure could be detected.
  
  
  CONCLUSIONS
  Retropubic radical prostatectomy decreases membranous urethral microcirculation. However, this loss of vascularization does not have a major effect on distal sphincter function and continence after radical prostatectomy.
authors.affiliation: Clinic of Urology, Zürich University Hospital, Zürich, Switzerland.
authors.forename: Hubert
authors.initials: H
authors.lastname: John
authors.forename: Stefan
authors.initials: S
authors.lastname: Suter
authors.forename: Dieter
authors.initials: D
authors.lastname: Hauri
mesh_terms: D006801:Humans; D017078:Laser-Doppler Flowmetry; D008297:Male; D008833:Microcirculation; D011468:Prostatectomy / Q000009:adverse effects* / Q000379:methods; D012039:Regional Blood Flow; D014521:Urethra / Q000098:blood supply* / Q000502:physiology*; D014554:Urination