Renal trauma

Renal trauma can result from direct, blunt, penetrating and iatrogenic injury.

Renal injuries account for ~10% of abdominal trauma, and thus the demographic of affected individuals reflects that population. The incidence of renal injuries increases in pre-existing congenital or acquired renal pathology (e.g. horseshoe kidney, renal cysts).

Patients tend to present with microscopic or macroscopic hematuria and flank and/or abdominal pain. In more severe cases, hypotension and shock may be present.

The vast majority of isolated renal trauma is minor (95-98%), the low incidence of major renal injuries is explained by the favourable anatomic position of the kidneys, which are located in the retroperitoneum.

Imaging generally should be reserved for the haemodynamically-stable patient; those who are haemodynamically-unstable are often taken directly to the operating theater.

Blunt trauma from motor vehicle collisions, falls, and personal collisions are the leading cause of renal injury (~85%), the mechanism is from deceleration injuries from a collision of the kidney with the vertebral column or thoracic cage.

Iatrogenic injuries can result from surgery, percutaneous renal biopsy, nephrostomy and extracorporeal shock wave lithotripsy (ESWL).

The vast majority (95-98%) of renal injuries are minor. The spectrum of renal injuries include:

Serious renal injuries from blunt and penetrating trauma are associated with multiorgan injuries in ~80% of cases 5.

May detect hemoperitoneum but is not as accurate as CT at diagnosing renal parenchymal injuries 5.

Due to the limited accessibility in the acute setting, and the lack of strong evidence (or expertise) CEUS is currently rarely used in the context of renal trauma. However in select cases it can be a valuable tool for problem-solving or follow-up (e.g. to reduce ionizing radiation exposure). The renal cortex demonstrates a rapid and early enhancement normally, followed by that the pyramids. Renal injuries such as lacerations appear as hypoenhancing areas, which are often wedge-shaped. Focal, patchy accumulations of contrast agent microbubbles are highly suggestive of active bleeding. If both kidneys need to be interrogated two separate contrast agent boluses are recommended. It is important to know however that CEUS does not detect collecting system injuries since the microbubbles remain intravascular 6

CT is the mainstay for diagnosing renal injuries:

  • CT multiphase protocol study for suspected renal trauma includes a non-contrast phase, an arterial phase to evaluate vascular injury, a nephrographic phase to evaluate renal parenchymal lesions and a delayed phase to evaluate bleeding and collecting system injuries
  • an alternative protocol study is a portal venous phase followed by a delayed phase to assess for collecting system injury 5

See main article renal trauma grading for a detailed description of the AAST classification of renal injuries.

CT can provide most of the information required regarding vascular injuries, but angiography can be used to further delineate the area of injury as well as offering the opportunity for treatment with angioembolisation 5.

Treatment depends on the specific trauma and complications present.

Complications affect ~7.5% (range 3-10%) of renal injuries 4,5:

Renal tumors can spontaneously hemorrhage, and cause perinephric fluid collection of blood density. These include:

Share article

Article information

rID: 24681
Synonyms or Alternate Spellings:
  • Traumatic kidney injury
  • Kidney injury
  • Renal trauma
  • Renal laceration
  • Traumatic renal injuries
  • Renal injuries
  • Renal contusion
  • Avulsion of renal pedicle
  • Renal haemorrhage
  • Renal injury

Support Radiopaedia and see fewer ads

Cases and figures

  • Case 1: traumatic rupture (gross pathology)
    Drag here to reorder.
  • Case 2
    Drag here to reorder.
  • Case 3: renal artery thrombosis (CT)
    Drag here to reorder.
  • Case 3: renal artery thrombosis (DSA)
    Drag here to reorder.
  • Case 4: renal artery pseudoaneurysm (DSA)
    Drag here to reorder.
  • Case 4: renal artery pseudoaneurysm (CT)
    Drag here to reorder.
  • Case 5: Grade II
    Drag here to reorder.
  • Case 6; subcapsular hematoma
    Drag here to reorder.
  • Case 7
    Drag here to reorder.
  • Case 8: grade V
    Drag here to reorder.
  • Case 9: perinephric hematoma
    Drag here to reorder.
  • Case 10: laceration with urine leak
    Drag here to reorder.
  • Case 11: with hemorrhage into renal cyst
    Drag here to reorder.
  • Case 12: perinephric hematoma and urine leak
    Drag here to reorder.
  • Case 13: in pregnancy
    Drag here to reorder.
  • Case 14: CEUS of kidney laceration
    Drag here to reorder.
  • Updating… Please wait.

     Unable to process the form. Check for errors and try again.

     Thank you for updating your details.