title: The fish-hook configuration of the distal ureter indicates bladder outlet obstruction due to benign prostatic hyperplasia.
abstract: OBJECTIVE
  The aim of this retrospective study was to evaluate in a historical series of patients whether morphological changes of the urinary tract imaged on intravenous urography (IVU) are associated with clinical or urodynamic data.
  
  
  METHODS
  During a 1-year period, every man 45 years or older with lower urinary tract symptoms suggestive of benign prostatic hyperplasia was systematically evaluated with multi-channel computer-urodynamic investigation and IVU. Men with urinary retention, known bladder stones or diverticula, severely impaired renal function, or allergy to iodine contrast media were excluded. Structural alterations of the urinary tract were correlated with clinical and urodynamic data using logistic regression analysis.
  
  
  RESULTS
  Data on 203 consecutive patients were available for analysis. Multivariate analysis demonstrated that the "fish-hook" configuration of the distal ureter (also known as "hockey-stick", or "J-shaped" ureter) was the only sign significantly associated with benign prostatic obstruction (BPO) (odds-ratio 3.64; 95% confidence interval 1.69-7.83; P < 0.001). The sensitivity, specificity, positive and negative predictive values of the "fish-hook" ureter configuration sign to detect BPO was 53, 76, 61 and 70%, respectively. Bladder trabeculation, upper urinary tract dilatation, or bladder base elevation were not associated with BPO, detrusor overactivity, detrusor underactivity, bladder low-compliance or any clinical data.
  
  
  CONCLUSIONS
  The "fish-hook" shape of the distal ureter(s) indicates BPO and may be a result of prostate median lobe enlargement.
authors.affiliation: Department of Urology, University of Crete Medical School, Heraklion, Crete, Greece.
authors.forename: Charalampos
authors.initials: C
authors.lastname: Mamoulakis
authors.forename: Thomas R W
authors.initials: TR
authors.lastname: Herrmann
authors.forename: Klaus
authors.initials: K
authors.lastname: Höfner
authors.forename: Matthias
authors.initials: M
authors.lastname: Oelke
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005858:Germany; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011470:Prostatic Hyperplasia / Q000150:complications* / Q000503:physiopathology; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014513:Ureter / Q000000981:diagnostic imaging* / Q000503:physiopathology; D001748:Urinary Bladder Neck Obstruction / Q000000981:diagnostic imaging* / Q000209:etiology* / Q000503:physiopathology; D014567:Urography