Renal Trauma

Table 5.7. the american association for the surgery of trauma

classification of renal injury

grade 1

cortical contusion, urological studies

normal

grade 2

non-expanding perirenal hematoma –

confined to retroperitoneum.

superficial cortical laceration < 1 cm,

without urinary extravasation

grade 3

cortical laceration > 1 cm but no

urinary extravasation

grade 4

cortical lacerations involving the

collecting system

main renal artery or vein injury with

contained hemorrhage

grade 5

shattered kidney

avulsion of the renal hilum with

Figure 5.37.

nephrostomy drain: Pigtail lies within the renal pelvis.

devascularized kidney

88

Practical Urology: EssEntial PrinciPlEs and PracticE

The majority (over 90%) of renal injuries are

obtained 5-20 minutes following contrast injec-

classified as minor and can be managed conser-

tion if there is concern regarding injury to the

vatively. Open exploration and possible nephre-

collecting system.

ctomy is indicated in patients with persistent

CT accurately demonstrates parenchymal lac-

life-threatening hemorrhage16.

erations which are identified as hypoattenuating

Ultrasound can detect renal subcapsular

areas or perfusion defects within the renal cortex

hematomas and has a high sensitivity for demon-

(Fig.5.38).Major lacerations extend into the renal

stration of intraperitoneal blood. However, it is a

medulla and may involve the collecting system.

relatively poor test for detecting renal lacerations

Subcapsular and perinephric hematoma can

and is therefore of limited value for the assess-

be recognized as a high attenuation collection

ment of patients with suspected renal injury.

adjacent to the renal cortex.

IVU can identify injuries involving the renal

Vascular injuries can be serious and life-

collecting system by demonstrating contrast

threatening. Trauma to the renal pedicle can

extravasation. Renal parenchymal injuries how-

result in renal artery occlusion leading to renal

ever are not adequately demonstrated by IVU

infarction (Fig. 5.39). Contrast-enhanced CT

and its role has largely been replaced by CT.

demonstrates abrupt occlusion of the renal

Contrast-enhanced CT is the imaging modal-

artery with non-enhancement of the kidney

ity of choice for assessment of renal trauma and

indicating renal infarction. More serious inju-

can help differentiate between those injuries

ries can result in avulsion of the renal pedicle

that can be managed conservatively from those

leading to catastrophic hemorrhage.

that require surgical intervention.

AV fistula or pseudoaneurysm formation can

Major renal trauma is frequently associated

occur following penetrating renal trauma

with injuries to the chest and other abdominal

(Fig. 5.40). Angiographic studies with a view to

organs. CT can detect a wide range of intra-

therapeutic embolization may be necessary in

abdominal injuries and the study can be

these types of injury.

extended to include the thorax if required.

Major renal trauma is frequently associated

Post iv contrast studies are obtained to iden-

with injuries to the chest and other abdominal

tify renal cortical laceration, vascular injuries

organs. CT can detect a wide range of intra-

and haematoma formation. These can be sup-

abdominal injuries and the study can be

plemented by delayed excretory phase images

extended to include the thorax if required.

Figure 5.38. grade 3 injury involving left kidney demonstrating

Figure 5.39. non-enhancing right kidney as a result of trau-

a cortical laceration and retroperitoneal hematoma.

matic infarction.