What is the appropriate management for a patient with suspected kidney trauma?

Management of Kidney Trauma

Non-operative management (NOM) should be the treatment of choice for all hemodynamically stable or stabilized patients with kidney trauma, regardless of injury grade (AAST I-V), with contrast-enhanced CT scan with delayed urographic phase as the mandatory diagnostic tool to guide this approach. 1

Initial Assessment and Hemodynamic Stratification

Classify patients immediately into hemodynamic categories to determine the management pathway: 2

• Hemodynamically stable: Patients maintaining normal vital signs without resuscitation
• Transient responders: Patients who initially respond to fluid resuscitation but show signs of deterioration
• Non-responders (WSES IV): Patients remaining unstable despite active resuscitation

For hemodynamically unstable patients, proceed directly to operative management or angioembolization—do not delay for CT imaging. 2 Consider Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) as a temporizing bridge to definitive hemorrhage control. 1, 2

Diagnostic Imaging Protocol

In all hemodynamically stable or stabilized patients, perform IV contrast-enhanced CT scan with both immediate and delayed urographic phases (10-15 minutes post-contrast). 1, 3 This is the gold standard for:

• Accurate classification of injury grade (AAST I-V)
• Detection of arterial contrast extravasation
• Identification of urinary extravasation from collecting system injuries
• Assessment of associated injuries

Obtain CT imaging for patients with: 2, 3

• Gross hematuria
• Microscopic hematuria with systolic BP <90 mmHg
• High-energy deceleration mechanism
• Significant flank trauma or rib fractures
• Any penetrating injury to abdomen, flank, or lower chest (regardless of hematuria presence)

Non-Operative Management Strategy

NOM is appropriate for all injury grades (AAST I-V) in hemodynamically stable or stabilized patients. 1, 2 This approach requires:

• Immediate availability of operating room, surgeons, and interventional radiology 1
• High-dependency or intensive care monitoring environment 1
• Immediate access to blood products 1, 2
• Serial clinical examinations and laboratory monitoring 1

Critical point: Isolated urinary extravasation alone is NOT an absolute contraindication to NOM in the absence of other surgical indications. 1 These injuries often resolve spontaneously with observation. 1

For penetrating lateral kidney injuries, NOM is feasible but requires meticulous patient selection—cases without peritoneal cavity violation are most suitable. 1

Angiography and Angioembolization Indications

Perform angiography with selective angioembolization in hemodynamically stable or stabilized patients with: 1, 2

• Arterial contrast extravasation on CT
• Pseudoaneurysms
• Arteriovenous fistula
• Non-self-limiting gross hematuria

Angioembolization should be performed as selectively as possible to preserve renal function. 1 Super-selective techniques achieve 63-100% success rates in controlling bleeding. 4

Do NOT perform blind angioembolization in stable patients with both kidneys when angiography shows no active bleeding, regardless of CT findings. 1 This critical distinction prevents unnecessary renal parenchymal loss.

For solitary kidney with moderate (AAST III) or severe (AAST IV-V) trauma showing arterial extravasation, angiography with super-selective embolization should be first-line treatment. 1

In main renal artery injury, dissection, or occlusion with limited warm ischemia time (<240 minutes), consider angioembolization and/or percutaneous revascularization with stent/stentgraft in specialized centers. 1

If initial angioembolization fails in stable patients without other surgical indications, repeat angioembolization should be attempted before proceeding to surgery. 1

Operative Management Indications

Proceed immediately to operative management for: 1, 2, 4

• Hemodynamically unstable non-responders (WSES IV) despite resuscitation
• Severe renal vascular injuries (main renal vein injury) without self-limiting bleeding
• Expanding or pulsatile perirenal hematoma at laparotomy
• Failed angioembolization with persistent bleeding

Important caveat: The presence of non-viable devascularized kidney tissue is NOT an indication for acute operative management in the absence of other surgical indications. 1 Delayed nephrectomy can be performed electively if needed.

During damage control laparotomy, if a perirenal hematoma is stable and non-expanding, leave it alone and obtain postoperative CT imaging rather than exploring reflexively. 5 Exploration of stable hematomas significantly increases nephrectomy rates.

Management of Urinary Extravasation

Observe patients with renal parenchymal injury and urinary extravasation initially without intervention, provided renal pelvis or proximal ureteral injury is not suspected. 1 Most collecting system injuries resolve spontaneously.

Perform urinary drainage (ureteral stent ± percutaneous nephrostomy) when complications develop: 1, 4

• Enlarging urinoma
• Fever or infection
• Increasing pain
• Ileus
• Fistula formation

An internalized ureteral stent alone is often adequate and minimally invasive—ensure follow-up mechanisms for stent removal. 1 Concomitant Foley catheter drainage may enhance urinoma resolution.

When renal pelvis or proximal ureteral avulsion is suspected (large medial urinoma or contrast extravasation without distal ureteral filling), prompt intervention is warranted—either endoscopic or open depending on clinical scenario. 1

Follow-Up Imaging

For AAST Grade I-III injuries: Routine follow-up CT imaging is NOT indicated in asymptomatic patients due to low complication rates, avoiding unnecessary radiation exposure and cost. 1

For AAST Grade IV-V injuries: Perform follow-up CT imaging after 48-72 hours as these deep lacerations are prone to complications including urinoma and delayed hemorrhage. 1, 4

Obtain follow-up imaging at any time if clinical signs of complications develop: 1

• Fever
• Worsening flank pain
• Ongoing blood loss
• Abdominal distention
• New-onset hematuria (may indicate pseudoaneurysm or AV fistula, occurring in up to 25% of moderate/severe injuries within 2 weeks) 4

Return to Activity

Restrict sport activities until microscopic hematuria resolves completely. 1, 4 Recommended timeframes:

• Minor/moderate injuries (AAST I-III): 2-6 weeks 4
• Severe injuries (AAST IV-V): 6-12 months 4

Critical Pitfalls to Avoid

Never transport hemodynamically unstable patients to CT scanner—imaging must not delay hemorrhage control. 2 Obtain bedside pelvic X-ray and E-FAST only during ongoing resuscitation. 2

Do not perform nephrectomy reflexively in unstable patients with severe renal injuries—kidney-preserving techniques should be attempted when feasible. 2 The shift toward conservative management has dramatically improved renal salvage rates.

Do not explore stable, non-expanding perirenal hematomas during laparotomy for other injuries—this significantly increases unnecessary nephrectomy rates. 5

Do not assume NOM has failed after a single angioembolization attempt—repeat selective embolization should be considered before proceeding to surgery in stable patients. 1

Do not attempt NOM in facilities lacking immediate access to interventional radiology, surgical capabilities, and intensive care monitoring—these are absolute prerequisites for safe conservative management. 4