Table 1: AAST classification of renal injuries [9].

Grade Type of Injury Description I Normal contusion Microscopic or gross hematuria with normal urologic findings Hematoma Nonexpanding subcapsular hematomas with no laceration II Hematoma Nonexpanding perinephric (perirenal) hematomas confined to the retroperitoneum Laceration Superficial cortical lacerations less than 1 cm in depth without collecting system injury III Laceration Renal lacerations greater than 1 cm in depth without collecting system injury IV Laceration Renal lacerations extending through the renal cortex, medulla, and collecting system Vascular injury Injuries involving the main renal artery or vein with contained hematoma, segmental infarctions without associated lacerations V Laceration Shattered kidney, ureteropelvic junction avulsions Vascular injury Complete laceration (avulsion) or thrombosis of the main renal artery or vein that devascularizes the kidney