Evaluation of urinary extravasation after non-operative management of traumatic renal injury: a multi-center retrospective study

Purpose Urinary extravasation is one of the major complications after non-operative management of traumatic renal injury and may lead to urinary tract infection and sepsis. The purpose of this study was to evaluate these factors in patients with traumatic renal injury. Methods This was a multi-center, retrospective, observational study performed at three tertiary referral hospitals in Osaka prefecture. We included patients with traumatic renal injury transported to the centers between January 2008 and December 2018. We excluded patients who either died or underwent nephrectomy within 24 h after admission. We investigated the occurrence of urinary extravasation and the related factors after traumatic renal injury using multivariable logistic regression analysis. Results In total, 146 patients were eligible for analysis. Their median age was 44 years and 68.5% were male. Their median Injury Severity Score was 17. Renal injuries were graded as American Association for Surgery of Trauma (AAST) grade I in 33 (22.6%), II in 27 (18.5%), III in 38 (26.0%), IV in 28 (19.2%), and V in 20 (13.7%) patients. Urinary extravasation was diagnosed in 26 patients (17.8%) and was statistically significantly associated with AAST grades IV-V (adjusted odds ratio, 33.8 [95% confidence interval 7.12-160], p < 0.001). Conclusion We observed urinary extravasation in 17.8% of patients with non-operative management of traumatic renal injury and the diagnosed was made in mostly within 7 days after admission. In this study, the patients with AAST grade IV-V injury were associated with having urinary extravasation.