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

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). 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. 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. 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.