Incidence of urinary extravasation and rate of ureteral stenting after high-grade renal trauma in adults: a meta-analysis

Sorena Keihani, Ross E. Anderson, Michelle Fiander, Mary M. McFarland, Gregory J. Stoddard, James M. Hotaling, Jeremy B. Myers


Background: Collecting system injury and urinary extravasation is an important yet understudied aspect of renal trauma. We aimed to examine the incidence of urinary extravasation and also the rates of ureteral stenting after high-grade renal trauma (HGRT) in adults.
Methods: A search strategy was developed to search Ovid Medline, Embase, CINAHL, and Cochrane Library. Two reviewers screened titles and abstracts, followed by full-text review of the relevant publications. Studies were included if they indicated the number of patients with HGRT [the American Association for the Surgery of Trauma (AAST) grades III–IV or equivalents] and number of patients with urinary extravasation. A descriptive meta-analysis of binary proportions was performed with random-effects model to calculate the incidence of urinary extravasation and rates of ureteral stenting.
Results: After screening, 24 and 20 studies were included for calculating urinary extravasation and stenting rates, respectively. Most studies involved blunt injury and were retrospective single-center case series. Incidence of urinary extravasation was 29% (95% CI: 17–42%) after HGRT (grade III–V), and 51% (95% CI: 38–64%) when only grade IV–V injuries were combined. Overall, 29% (95% CI: 22–36%) of patients with urinary extravasation underwent ureteral stenting.
Conclusions: Approximately 30% of patients with HGRT are diagnosed with urinary extravasation and 29% of those with urinary extravasation undergo ureteral stenting. Understanding the rate of urinary extravasation and interventions is the first step in creating a prospective trial designed to demonstrate when ureteral stenting and aggressive management of urinary extravasation is needed.