Renal trauma AAST grading

Anatomic severity of renal injury stratifies mainly by depth of laceration, collecting system involvement, and vascular injury/active bleeding.

Grade I (minor)

• Contusion or subcapsular haematoma
• No laceration

Grade II (mild)

• Perirenal haematoma confined to Gerota fascia
• Cortical laceration <= 1 cm depth, no collecting system injury, no urine extravasation

Grade III (moderate)

• Laceration > 1 cm depth, no collecting system rupture, no urine extravasation
• Active bleeding or vascular injury that is contained within Gerota fascia (still “contained”)

Grade IV (high grade)

Any of:

• Laceration into collecting system with urinary extravasation
• Renal pelvis laceration and/or complete ureteropelvic junction disruption
• Segmental renal artery or vein injury
• Active bleeding extending beyond Gerota fascia (into retroperitoneum or peritoneum)
• Segmental or global infarction(s) from vessel thrombosis without active bleeding

Grade V (critical)

• Main renal artery or vein laceration, or hilar avulsion
• Devascularised kidney with active bleeding (2018 revision nuance)