- In UK, 90% of renal injuries result from blunt trauma
- Isolated renal trauma is uncommon
- About 40% have associated intra-abdominal injuries
- Direct trauma crushes kidney against ribs
- Indirect trauma can result in vascular or pelviureteric disruption
Clinical features
- Loin or abdominal abrasions or bruising
- Loin tenderness
- Loss of loin contour
- Loin mass
- Macroscopic haematuria +/- clot colic
- A renal pedicle injury is possible in the absence of haematuria
Imaging
- The aims of imaging are to:
- Assess extent of injury
- Determine function of contralateral kidney
- Plain radiograph may show rib fractures, loss of psoas shadow and renal outline
- Stable patients with microscopic haematuria do not require an IVU
- IVU will detect extravasation of urine and distortion of calyceal system
- Provides a crude index of renal function
- Failure of excretion suggests renal pedicle injury and need for angiography
- Ultrasound will identify haematomas and perirenal collections
Picture provided by Mr J C Campbell, Derriford Hospital, Plymouth, United Kingdom
Classification
- Class I - Renal contusion or contained subcapsular haematoma
- Class II - Cortical laceration without urinary extravasation
- Class III - Parenchymal lesion extending more than 1 cm into renal substance
- Class IV - Laceration extending across cortico-medullary junction
- Class V - Renal fragmentation or reno-vascular pedicle injury
Picture provided by Mr J C Campbell, Derriford Hospital, Plymouth, United Kingdom
Management
- 80% injuries are minor (Class I/II) and can be managed conservatively
- Early surgical intervention is required for:
- Reno-vascular pedicle injury
- Pelviureteric junction disruption
- Shock with signs of intraperitoneal or retroperitoneal trauma
- Surgery should be performed through a midline incision and transperitoneal approach
- Control of the renal pedicle should be obtained before the retroperitoneal haematoma is opened
- Surgical priorities are:
- Save like - early nephrectomy may be required
- Remove devitalised tissue
- Preserve renal function - consider partial nephrectomy if possible
- Repair and drain collecting system
Late complications
- Hypertension
- Arteriovenous fistula
- Hydronephrosis
- Pseudocyst or calculi formation
- Chronic pyelonephritis
- Loss of renal function
Bibliography
Goodacre B, van Sonnenberg E. Radiologic evaluation of renal trauma. Intensive Care Med
2000; 15: 90-98.
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