Penetrating renal trauma: CT evaluation.

Mandatory surgical exploration of penetrating renal injuries has been advocated for adequate assessment and repair of renal and retroperitoneal injuries. We evaluated 27 consecutive patients with deep stab wounds of the flank and back who were thought to be at risk for renal injury. Twenty-two patients were studied by CT, 11 by excretory urography, and three by angiography. No correlation was found between the presence and amount of hematuria and the extent of renal injury. Excretory urography was also of little use; the extent of renal parenchymal injury was underestimated, overestimated, or indeterminate in many cases. Computed tomography gave an accurate assessment of the extent of parenchymal damage, perirenal hemorrhage, extravasation of urine, and extrarenal injuries. Angiography was rarely required to better define renal vascular injuries. Only seven patients required surgical repair; the 20 patients managed nonoperatively included seven patients with renal lacerations considered minor by CT evaluation. We conclude that most patients with penetrating trauma do not require surgical exploration. The combination of clinical and CT criteria allows confident management in almost all cases. Computed tomography should be the primary diagnostic study in patients with penetrating back or flank trauma judged to be at risk for renal or other retroperitoneal injury.