What is the recommended follow-up and management for a patient with a renal hematoma?

Management and Follow-up of Renal Hematoma

Follow-up CT imaging is recommended for renal hematomas, particularly for deep lacerations (AAST Grade IV-V) or when patients show clinical signs of complications such as fever, worsening flank pain, ongoing blood loss, or abdominal distention. 1

Initial Assessment and Risk Stratification

The approach to renal hematoma management depends on:

1. Hemodynamic stability:

   • Unstable patients with no or transient response to resuscitation require immediate intervention (surgery or angioembolization) 1
   • Stable patients can typically be managed conservatively with observation 1

2. Severity of injury:

   • Low-grade injuries (AAST Grade I-III): Lower risk of complications
   • High-grade injuries (AAST Grade IV-V): Higher risk of complications requiring closer monitoring

Follow-up Imaging Protocol

For Low-Grade Renal Hematomas (AAST Grade I-III):

• Routine follow-up imaging is generally not required 1, 2
• Benefits of avoiding routine imaging include:
  • Reduced radiation exposure
  • Decreased risk of contrast complications
  • Improved patient convenience
  • Lower healthcare costs 2

For High-Grade Renal Hematomas (AAST Grade IV-V):

• Follow-up CT imaging with contrast and excretory phase is recommended within 48 hours 1, 2
• These injuries have higher risk of complications such as:
  • Urinoma formation
  • Ongoing hemorrhage
  • Urinary extravasation 2

For Any Grade with Clinical Deterioration:

• Immediate follow-up imaging is indicated for:
  • Fever
  • Worsening flank pain
  • Ongoing blood loss
  • Abdominal distention 1, 2

Imaging Modality Selection

• CT scan with contrast (including delayed excretory phase) is the preferred modality for follow-up of moderate to severe renal injuries 2
• Alternative modalities for follow-up:
  • Ultrasound or contrast-enhanced ultrasound (CEUS) should be considered as first choice for follow-up 2
  • MRI is preferred over CT when possible to reduce radiation exposure, especially in patients with renal dysfunction 2

Duration of Follow-up

• Most uncomplicated renal hematomas resolve spontaneously within 6 months 3
• For persistent hematomas:
  • Periodic clinical evaluation and laboratory testing for sequelae of treatment 1
  • Laboratory testing should include serum creatinine, estimated glomerular filtration rate, and urinalysis 1
  • Additional laboratory evaluations (CBC, LDH, liver function tests, alkaline phosphatase, calcium) may be obtained if advanced disease is suspected 1

Special Considerations

• Hypertension monitoring: Patients with renal hematomas should be monitored for hypertension, which can occur due to Page kidney phenomenon (external compression of kidney by hematoma) 4, 5

• Residual stone management: Presence of hematoma is not a contraindication for further treatments of residual stones, but caution should be exercised 6

• Nephrology referral: Appropriate referral to nephrology may help prevent further deterioration of renal function 1

Pitfalls to Avoid

1. Over-imaging: Routine follow-up imaging for uncomplicated low-grade injuries leads to unnecessary radiation exposure 1, 2

2. Delayed intervention: Failing to recognize clinical deterioration requiring prompt imaging and potential intervention

3. Inadequate imaging protocol: Not including delayed (excretory) phase in CT imaging, which is essential to identify urine leaks and collecting system injuries 2

4. Missing hypertension: Failing to monitor blood pressure during follow-up, as renal hematomas can cause hypertension 4