title: Longitudinal observational cohort study about detrusor underactivity as a risk factor for bladder neck contracture after retropubic radical prostatectomy: preliminary results.
abstract: OBJECTIVE
  To evaluate the association between preoperative detrusor underactivity (DU) and symptomatic bladder neck contracture (BNC) in patients undergoing radical retropubic prostatectomy (RRP), in order to identify a possible new risk factor in the etiopathogenic mechanisms of BNC after RRP.
  
  
  METHODS
  A total of 100 prostate cancer patients underwent RRP after preoperative complete urodynamic examination. Detrusor contractility was evaluated by bladder contractility index (BCI), power at maximum flow (WF-Qmax), and maximum velocity of detrusorial contraction (MVDC). Follow-up included uroflowmetry with bladder post-voiding volume evaluation at 3 and 6 months after surgery and repeated urodynamic examination at 12 months. Statistical evaluation was performed using the Student's t test (P < 0.01).
  
  
  RESULTS
  The mean patient age was 65.6 ± 5.4 years, and pathological stage ranged from T2a to T2c. A total of 40 patients (40 %) presented normal detrusor contractility, 47 (47 %) mild DU, and 13 (13 %) severe DU. Detrusor overactivity (DO) was observed in 12 patients (12 %), small cystometric capacity in 10 (10 %), low compliance in 16 (16 %), DO plus DU (mild or severe) in 6 (6 %), and DO plus small cystometric capacity together with low compliance in 5 (5 %). Normal urodynamics were observed in 38 patients (38 %). Overall BNC incidence was 12. All patients with BNC presented preoperative DU; none presented DO or low bladder compliance. DU severity and BNC occurrence were significantly correlated (P < 0.01) for all 3 urodynamic parameters (BCI, WF-Qmax, and MVDC).
  
  
  CONCLUSIONS
  We identify DU as a possible novel risk factor for BNC formation after radical prostatectomy that may contribute to its development.
authors.affiliation: Department of Urology, University of Messina, Via Consolare Valeria, 98100, Messina, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Mucciardi
authors.forename: Alessandro
authors.initials: A
authors.lastname: Galì
authors.forename: Antonino
authors.initials: A
authors.lastname: Inferrera
authors.forename: Antonina
authors.initials: A
authors.lastname: Di Benedetto
authors.forename: Luciano
authors.initials: L
authors.lastname: Macchione
authors.forename: Massimo
authors.initials: M
authors.lastname: Mucciardi
authors.forename: Carlo
authors.initials: C
authors.lastname: Magno
mesh_terms: D000368:Aged; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D011468:Prostatectomy / Q000009:adverse effects* / Q000379:methods; D011471:Prostatic Neoplasms / Q000473:pathology / Q000601:surgery*; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D001743:Urinary Bladder / Q000503:physiopathology*; D001748:Urinary Bladder Neck Obstruction / Q000209:etiology* / Q000503:physiopathology; D014549:Urinary Incontinence / Q000150:complications* / Q000503:physiopathology; D014563:Urodynamics / Q000502:physiology*