Peterson used a simple classification system to describe traumatic renal injury. This correlates with the need for surgical intervention.


Classification of renal trauma

Need for Surgery

minor (Grade I)

rarely if ever

intermediate (Grade II)


major (Grade III)



Features of major renal trauma:

(1) severe, unremitting hemorrhage

(2) absent urographic function

(3) unstable hemodynamically

(4) parenchymal shattering and/or vascular interruption at the renal pedicle


Intermediate renal trauma involves laceration with extravasation of blood. These lesions often heal spontaneously even when deep or involving the collecting system. Surgery is needed when the bleeding does not resolve or if a urinoma develops.


Minor renal trauma is any that is not intermediate or major.


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