What is a retroperitoneal hematoma?

What is a Retroperitoneal Hematoma?

A retroperitoneal hematoma is a collection of blood in the retroperitoneal space—the anatomical compartment behind the peritoneum that contains major vessels, kidneys, pancreas, and other structures—resulting from bleeding that is not readily accessible to physical examination and often presents with nonspecific symptoms. 1

Anatomical Definition and Location

The retroperitoneum is divided into three distinct zones for clinical management purposes 2:

• Zone 1 (central): Extends from the esophageal hiatus to the sacral promontory, containing the aorta, inferior vena cava, and major visceral vessels 2
• Zone 2 (lateral): Extends from the lateral diaphragm to the iliac crest, containing the kidneys and ureters 2
• Zone 3 (pelvic): Confined to the retroperitoneal space of the pelvic bowl 2

Common Etiologies

Iatrogenic Causes (Most Common in Modern Practice)

• Femoral vascular access procedures: Retroperitoneal hematoma occurs in 0.5% of all cardiac catheterizations, with the highest frequency (3%) after coronary artery stenting 3
• Surgical complications: Any retroperitoneal surgical procedure can result in hematoma formation 4
• J-tube placement: Direct vascular injury during needle passage or tract creation through the abdominal wall can cause retroperitoneal bleeding 5

Spontaneous Causes

• Anticoagulation therapy: The most important cause of spontaneous retroperitoneal bleeding, particularly with excessive anticoagulation 4
• Ruptured aortic aneurysm: A critical, life-threatening cause requiring urgent intervention 4
• Malignancy: The second most common site of major bleeding in cancer patients, either from the tumor itself or cancer treatments including chemotherapy 1, 4

Traumatic Causes

• Pelvic fractures: Account for 55% of retroperitoneal hematomas from blunt trauma and are associated with increased transfusion requirements 4
• Visceral vessel injury: Can result in significant retroperitoneal bleeding 4, 2

Clinical Presentation

Why Diagnosis is Challenging

The diagnosis is frequently delayed because the retroperitoneal location makes bleeding inaccessible to physical examination, and symptoms are highly nonspecific 1, 6:

• Suprainguinal tenderness and fullness: Present in 100% of iatrogenic cases 3
• Severe back and lower quadrant pain: Occurs in 64% of cases 3
• Diffuse abdominal pain, flank pain, or abdominal distension: Common nonspecific presentations 4, 5
• Femoral neuropathy: Develops in 36% of cases due to nerve compression 3
• Hemodynamic instability: Hypotension and signs of hypovolemia in severe cases 5

Diagnostic Approach

Imaging Modalities

CT abdomen and pelvis is the primary diagnostic tool due to its speed, high spatial resolution, and noninvasiveness 1:

• Noncontrast CT: Can expeditiously confirm or exclude bleeding; high attenuation indicates acute bleeding, while mixed attenuation suggests subacute bleeding 1
• CT with IV contrast or CTA: Superior for detecting active bleeding, localizing the source, and identifying underlying causes such as pelvic fracture or mass 1, 5
• Angiography: Requires bleeding rate of 0.5-1.0 mL/min for detection; reserved for hemodynamically unstable patients or when simultaneous diagnosis and treatment with transcatheter arterial embolization is planned 1

Management Strategy

Hemodynamically Stable Patients

Most patients can be managed conservatively with 3, 6:

• Fluid resuscitation and blood transfusion
• Correction of coagulopathy (INR <1.5, platelets >50,000/μL) 5
• Serial monitoring of hemoglobin and vital signs

Hemodynamically Unstable Patients

Patients with hypotension unresponsive to volume resuscitation require urgent intervention 3:

• Angioembolization: Treatment of choice for arterial contrast extravasation, pseudoaneurysms, or arteriovenous fistula; achieves cessation of bleeding in nearly 100% of cases when active bleeding is identified 1, 5
• Open surgical repair: Reserved for failure of conservative or endovascular measures, unavailability of interventional radiology, or persistent instability 6

Zone-Specific Approach for Traumatic Cases

• Zone 1 (central) penetrating trauma: Always requires urgent surgical exploration due to great vessel injury 2
• Other zones: Should be evaluated by CT and/or angiography; ongoing hemorrhage may respond to therapeutic embolization 2

Critical Pitfalls to Avoid

• Do not delay CT imaging in stable patients with clinical suspicion, as early diagnosis significantly improves outcomes 5
• Do not perform procedures in patients with uncorrectable coagulopathy 5
• Do not assume stability based on initial presentation—16% of patients initially managed conservatively ultimately require surgery due to progressive bleeding 3