The decision to repair or remove the damaged kidney at that time depends on the kidney's salvageability, the patient's ability to tolerate the procedure, and the availability of resources. Kidney preservation should only be considered if the patient is hemodynamically stable, the surgeon has experience with renorrhaphy, and has considered this after discussion with a urologist. Renal preservation strategies include conservative management, selective angioembolization, and renorrhaphy. The necessary resources and expertise for embolization or renorrhaphy may not be available in theater. Additionally, the risks of renorrhaphy (delayed bleed and/or urine leak) should be considered in determining the best management for the patient. Several studies raised concern that nephrectomy may be associated with increased mortality. However, these studies were not able to account for transfusion requirements.16,17 A more recent study which was able to control for the degree of transfusion concluded nephrectomy itself was not associated with mortality, and instead, shock is the driver of mortality in high-grade renal trauma.18 Although kidney preservation should be the goal in appropriate patients, surgeons should not hesitate to perform nephrectomy in unstable patients with high-grade renal trauma or when the necessary resources are unavailable for angioembolization or renorrhaphy. The presence of a contralateral kidney should be determined before nephrectomy by palpation or on-table imaging (e.g., one-shot IVP: 2 mL/kg IV bolus of contrast followed by a single abdominal radiograph 10-15 minutes later). High-velocity kidney injuries are difficult to reconstruct and often require nephrectomy. (See Nephrectomy Section in Appendix A: Urological Diagnosis and Treatments.) 19

An algorithmic approach to renal trauma management is presented in Figure 4 below.