Management of adult renal trauma: a practice management guideline from the eastern association for the surgery of trauma
Authors: Aziz Hiba Abdel , Bugaev Nikolay , Baltazar Gerard , Brown Zachary , Haines Krista , Gupta Sameer , Yeung Lawrence , Posluszny Joseph , Como John , Freeman Jennifer , Kasotakis George 
Published: January 2023

Abstract
Background
The kidney is the most frequently injured component of the genitourinary system, accounting for 5% of all trauma cases. Several guidelines by different societies address the management of urological trauma. However, unanswered questions remain regarding optimal use of angioembolization in hemodynamically stable patients, indications for operative exploration of stable retroperitoneal hematomas and renal salvage techniques in the setting of hemodynamic instability, and imaging practices for patients undergoing non-operative management. We performed a systematic review, meta-analysis, and developed evidence-based recommendations to answer these questions in both blunt and penetrating renal trauma.

Methods
The working group formulated four population, intervention, comparator, outcome (PICO) questions regarding the following topics: (1) angioembolization (AE) usage in hemodynamically stable patients with evidence of ongoing bleeding; (2) surgical approach to stable zone II hematomas (exploration vs. no exploration) in hemodynamically unstable patients and (3) surgical technique (nephrectomy vs. kidney preservation) for expanding zone II hematomas in hemodynamically unstable patients; (4) frequency of repeat imaging (routine or symptom based) in high-grade traumatic renal injuries. A systematic review and meta-analysis of currently available evidence was performed. RevMan 5 (Cochran Collaboration) and GRADEpro (Grade Working Group) software were used. Recommendations were voted on by working group members and concurrence was obtained for each final recommendation.

Results
A total of 20 articles were identified and analyzed. Two prospective studies were encountered; the majority were retrospective, single-institution studies. Not all outcomes projected by PICO questions were reported in all studies. Meta-analysis was performed for all PICO questions except PICO 3 secondary to the discrepant patient populations included in those studies. PICO 1 had the greatest number of articles included in the meta-analysis with nine studies; yet, due to differences in study design, no critical outcomes emerged; similar differences among a smaller set of articles prevented observation of critical outcomes for PICO 4. Analyses of PICOs 2 and 3 favored a non-invasive or minimally invasive approach in-line with current international practice trends.

Conclusion
In hemodynamically stable adult patients with clinical or radiographic evidence of ongoing bleeding, no recommendation could be made regarding the role of AE vs. observation. In hemodynamically unstable adult patients, we conditionally recommend no renal exploration vs. renal exploration in stable zone II hematomas. In hemodynamically unstable adult patients, we conditionally recommend kidney preserving techniques vs. nephrectomy in expanding zone II hematomas. No recommendation could be made for the optimal timing of repeat imaging in high grade renal injury.
Level of evidence: Guideline; systematic review, level III.