High‐grade renal injury: non‐operative management of urinary extravasation and prediction of long‐term outcomes

Abstract

Study Type – Therapy (outcomes) Level of Evidence 2b What's known on the subject? and What does the study add? High‐grade renal trauma seems to be eligible for conservative management. Ureteric stent placement raises issues about its usefulness and its timing. Predictive factors of post‐trauma function and surgery need to be known. Urinary extravasation is not associated with poor functional outcome. Ureteric stenting is needed only in case of sepsis and ureteric clot retention. The only independent predictor of long‐term renal function is the importance of devascularised renal fragments. OBJECTIVE To predict the outcomes of a non‐operative approach to managing urinary extravasation after blunt renal trauma. PATIENTS AND METHODS A prospective observational study was conducted between January 2004 and October 2011. First‐line non‐operative management was proposed for 99 patients presenting with a grade IV blunt renal injury according to the revised American Association for the Surgery of Trauma (AAST) classification. Among them, 72 patients presented with a urinary extravasation. Management and outcomes were recorded and compared between patients presenting and those who did not present with urinary leakage. Relative postoperative renal function was assessed 6 months after the trauma using dimercapto‐succinic acid renal scintigraphy. Predictors of the need for endoscopic or surgical management and long‐term renal function were evaluated on multivariate analysis. RESULTS Among patients with urinary leakage, endoscopic ureteric stent placement and open surgery were required in 37% and 15%, respectively. On multivariate analysis, fever of >38.5 °C and ureteric clot obstruction were independent predictors of the need for ureteric stent placement. The only predictor of open surgery was the percentage of devitalised parenchyma. Long‐term renal function loss was correlated to the percentage of devitalised parenchyma and associated visceral lesions. Urinary extravasation did not predict surgical intervention or long‐term renal function loss. CONCLUSIONS Urinary extravasation after blunt renal trauma can be successfully managed conservatively and does not predict long‐term decreased renal function or surgery requirement. A devascularised parenchyma volume of >25% predicts a higher rate of surgery and poorer renal function.