Diagnosis and management of urinary extravasation after high-grade renal trauma

Renal trauma research has historically focused on parenchymal injuries and the risk of bleeding. However, much less is known about the diagnosis and optimal management of urinary extravasation, which complicates similar to 30% of high-grade renal injuries. Immediate or delayed ureteral stenting is the most common procedure used to treat collecting system injuries when intervention is needed. However, the lack of evidence-based guidelines leaves the diagnosis and management of urinary extravasation largely dependent upon physicians' experience, initial and follow-up imaging protocols, and the definitions used for grading the injuries. The knowledge gaps in the management of urinary extravasation that need to be addressed include the timing of excretory-phase CT imaging, patterns of clinically significant urinary extravasation, predictors of complications when urinary extravasation occurs, protocols for obtaining and interpreting follow-up imaging, and the role of ureteral stenting and other interventions in management. To improve the management of urinary extravasation after high-grade renal trauma, large, multi-institutional prospective trails assessing different diagnostic and therapeutic protocols are needed.