Predictive factors for operation and mortality following renal trauma.

The incidence of injury to the urologic system after trauma is about 10%. Blunt trauma followed by traffic accidents and during sports comprise 90% of the etiologies. In addition, the rate of penetrating injuries is increasing, especially in urban areas. The kidney is the most common urologic organ to be injured, followed by urinary bladder and the urethra. Isolated urologic trauma is rare; therefore, it is important to consider possible potential urological injury in the multiple trauma patients. Renal injury happens in 8%e10% of all blunt and penetrating abdominal injuries and is frequently managed conservatively. However, it is important to diagnose renal pedicle injury or laceration of ureteropelvic junction with potential retroperitoneal hemorrhage or urinoma. Therefore, the optimal management of major blunt and penetrating renal injuries remains controversial and deserves further evaluation. In this issue, Dr. Yang and colleagues have done a good job of finding the factors predictive of surgery and mortality in patients with renal injury. Sudden deceleration or crash injury may induce contusion, laceration, rupture, or even total disintegration or disruption of the renal parenchyma. Damage of the renal pedicle through shearing forces may range from a tear leading to thrombosis of a renal artery or vein to partial or complete transection of the renal hilum. The accepted classification system for blunt renal injuries uses the grading system of the American Association for the Surgery of Trauma (AAST). In their article, Yang and others conclude that Injury Severity Score (ISS) 16 and Renal Injury Scale (RIS) 4 are predictive factors for operation, and that higher injury severity (ISS 16) and lower conscious level (Glasgow Coma Scale (GCS) < 8) are significantly associated with mortality after renal trauma. However, the authors could give more details about this scale and describe the numbers of patients in different RIS scales and their prognoses, because they want to find the predictive factors for surgery and mortality after renal trauma. In this way, the readers could get more information from the article. Recent papers have reported the rate of penetrating renal injury is increasing. In addition, iatrogenic injury by interventional procedures, such as renal biopsies under sono or computed tomography (CT) guidance or percutaneous nephrostomies, are other causes of penetrating renal trauma. In this paper, the authors did not mention about iatrogenic injury of kidney; they could give some comments in the discussion, which would inform the readers about this