Renovascular injuries from external trauma. Diagnosis, treatment, and outcome.

Blunt trauma of the deceleration or acceleration type is the most common cause of renal pedicle injuries comprising thrombosis or rupture of the main renal artery, branch renal artery, or the renal vein. There are no symptoms or signs specific to this injury, and hematuria is absent in one third of the cases. Severe multiple associated injuries are present in almost all cases, with a mortality rate of 44 per cent. Radiologic evaluation with intravenous urography shows nonappearance of the involved kidney. CT reveals nonenhancement of the kidney except for the periphery of the cortex from collateral circulation (rim sign), and renal arteriography shows occlusion of the renal artery or its branches. Despite immediate radiologic evaluation resulting in a short time from injury to diagnosis, most of the patients are not candidates for vascular repair owing to the high incidence of severe associated injuries, especially a second injury to the same kidney. Even with vascular repair, the function of the kidney is not restored to normal. Late hypertension is found in 50 per cent of patients with main renal artery thrombosis managed conservatively.