title: High-grade renal injury: non-operative management of urinary extravasation and prediction of long-term outcomes.
abstract: OBJECTIVE
  To predict the outcomes of a non-operative approach to managing urinary extravasation after blunt renal trauma.
  
  
  METHODS
  A prospective observational study was conducted between January 2004 and October 2011. First-line non-operative management was proposed for 99 patients presenting with a grade IV blunt renal injury according to the revised American Association for the Surgery of Trauma (AAST) classification. Among them, 72 patients presented with a urinary extravasation. Management and outcomes were recorded and compared between patients presenting and those who did not present with urinary leakage. Relative postoperative renal function was assessed 6 months after the trauma using dimercapto-succinic acid renal scintigraphy. Predictors of the need for endoscopic or surgical management and long-term renal function were evaluated on multivariate analysis.
  
  
  RESULTS
  Among patients with urinary leakage, endoscopic ureteric stent placement and open surgery were required in 37% and 15%, respectively. On multivariate analysis, fever of >38.5 °C and ureteric clot obstruction were independent predictors of the need for ureteric stent placement. The only predictor of open surgery was the percentage of devitalised parenchyma. Long-term renal function loss was correlated to the percentage of devitalised parenchyma and associated visceral lesions. Urinary extravasation did not predict surgical intervention or long-term renal function loss.
  
  
  CONCLUSIONS
  Urinary extravasation after blunt renal trauma can be successfully managed conservatively and does not predict long-term decreased renal function or surgery requirement. A devascularised parenchyma volume of >25% predicts a higher rate of surgery and poorer renal function.
authors.affiliation: Urology Department, Grenoble University Hospital, Grenoble, France. JALong@chu-grenoble.fr
authors.forename: Jean-Alexandre
authors.initials: JA
authors.lastname: Long
authors.forename: Gaelle
authors.initials: G
authors.lastname: Fiard
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Descotes
authors.forename: Valentin
authors.initials: V
authors.lastname: Arnoux
authors.forename: Alexis
authors.initials: A
authors.lastname: Arvin-Berod
authors.forename: Nicolas
authors.initials: N
authors.lastname: Terrier
authors.forename: Bernard
authors.initials: B
authors.lastname: Boillot
authors.forename: Olivier
authors.initials: O
authors.lastname: Skowron
authors.forename: Caroline
authors.initials: C
authors.lastname: Thuillier
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Rambeaud
mesh_terms: D000007:Abdominal Injuries / Q000175:diagnosis / Q000628:therapy*; D000293:Adolescent; D000328:Adult; D004724:Endoscopy / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007668:Kidney / Q000293:injuries*; D008297:Male; D011446:Prospective Studies; D015607:Stents; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D015599:Trauma Severity Indices; D016896:Treatment Outcome; D014556:Urine; D014949:Wounds, Nonpenetrating / Q000175:diagnosis / Q000628:therapy*; D055815:Young Adult