Long-term renal function assessment with dimercapto-succinic acid scintigraphy after conservative treatment of major renal trauma.

PURPOSE: The management of high grade blunt renal injury has evolved with time to become increasingly conservative with the ultimate objective of renal preservation. We evaluated relative renal function with dimercapto-succinic acid renal scintigraphy 6 months after major renal trauma (grade IV or V). MATERIALS AND METHODS: This prospective observational study was done between January 2004 and April 2010. All patients who presented with grade IV or V renal trauma and were treated conservatively were included in analysis. Patient and trauma characteristics, and initial management were recorded. Relative renal function was evaluated by dimercapto-succinic acid renal scintigraphy 6 months after trauma. RESULTS: A total of 88 patients were included in the study. Conservative management was possible in 79 patients (90%), including 69 and 10 with grade IV and V trauma, respectively. Dimercapto-succinic acid renal scintigraphy was done at 6 months for 22 patients (28%). Mean relative renal function for grade IV and V injuries was 39% and 11%, respectively (p=0.0041). The percent of devascularized parenchyma (p=0.0033) and the vascular subtype of grade IV injuries (p=0.0194) also correlated with decreased renal function. No complication or de novo arterial hypertension was noted. CONCLUSIONS: Conservative treatment achieves the objective of renal function preservation for grade IV lesions. Grade V and specific subtypes of grade IV injury have a poor functional outcome. Further study must be performed to determine which patients will benefit from conservative treatment vs early nephrectomy to avoid a longer hospital stay and useless procedures.