Successful conservative management of high-grade renal injury in a polytrauma patient: a rare case report.

Introduction and importance: Simultaneous high-grade renal and splenic trauma is rare and challenges the limits of non-operative management (NOM). High-grade renal injuries with collecting-system extravasation, especially when associated with severe splenic laceration, represent scenarios in which clinical decisions must rely primarily on physiologic stability rather than injury grade alone. Case presentation: An 18-year-old hemodynamically stable male presented 4 hours after a bicycle fall onto his left flank, with severe flank pain and gross hematuria. Computed tomography (CT) imaging revealed AAST Grade IV renal trauma with collecting-system involvement, together with concurrent Grade IV splenic laceration and associated nondisplaced rib fractures. The patient was managed with close ICU observation, multimodal analgesia, and serial monitoring. Diagnostic laparoscopy excluded ongoing intraperitoneal bleeding. A left double-J ureteric stent and intraperitoneal drain were placed for urinary diversion and controlled drainage. No nephrectomy, splenectomy, or splenic artery embolization was required. The patient improved steadily and was discharged in stable condition. Clinical discussion: Serial imaging demonstrated resolution of the perinephric hematoma and identified a nonenhancing, infarcted lower renal pole with preserved global renal function. Mild hydronephrosis, present while the stent was in place, resolved completely following elective removal. This case aligns with current NOM principles, showing that stability-guided conservative strategies with targeted minimally invasive interventions can safely preserve organs even in combined high-grade solid-organ injuries. Conclusion: Structured NOM involving ICU surveillance, temporary urinary diversion, selective minimally invasive procedures, and coordinated multidisciplinary care successfully preserved both renal and splenic function in this combined high-grade trauma case. The outcome supports stability-based decision-making over routine operative intervention and reinforces the safety and effectiveness of individualized conservative pathways in complex blunt abdominal trauma.