Overview
Definition:
A Zone II retroperitoneal hematoma (RPH) refers to bleeding within the retroperitoneal space, specifically in the anterior pararenal or perirenal compartments, often associated with vascular injuries
These hematomas can arise from trauma, iatrogenic causes, or spontaneous rupture of aneurysms or pseudoaneurysms
Zone II is typically bounded by the renal fascia and includes major vascular structures like the aorta and vena cava
Exploration is indicated for hemodynamically unstable patients or those with expanding hematomas.
Epidemiology:
Retroperitoneal hematomas account for a significant proportion of bleeding complications in abdominal trauma, with Zone II injuries being common
The incidence varies greatly depending on the mechanism of injury
blunt trauma has a higher incidence of RPH compared to penetrating trauma
Iatrogenic causes, particularly from vascular interventions, are also a notable contributor.
Clinical Significance:
Zone II RPH poses a life-threatening emergency due to the potential for rapid exsanguination and compression of vital organs
Prompt diagnosis and management are crucial to improve patient outcomes
Understanding the anatomy of Zone II and the potential vascular injuries is paramount for surgeons preparing for DNB and NEET SS examinations, as these scenarios frequently appear in exam questions.
Clinical Presentation
Symptoms:
Hypotension
Tachycardia
Abdominal pain, often diffuse
Flank pain
Back pain
Abdominal distension
Nausea and vomiting
Signs of hypovolemic shock.
Signs:
Tenderness in the abdomen or flank
Palpable abdominal mass or distension
Grey-Turner's sign (flank ecchymosis) or Cullen's sign (periumbilical ecchymosis) may indicate retroperitoneal bleeding but are often late findings
Pulsatile mass may suggest aortic involvement
Absence of bowel sounds in severe cases.
Diagnostic Criteria:
No specific diagnostic criteria exist beyond clinical suspicion and confirmation with imaging
Hemodynamic instability in the context of trauma or recent vascular procedure strongly suggests RPH
Imaging confirmation is key.
Diagnostic Approach
History Taking:
Detailed history of trauma mechanism (blunt vs
penetrating)
History of recent vascular interventions, anticoagulation, or bleeding disorders
Previous abdominal surgeries
Presence of comorbidities like hypertension or aneurysmal disease
Any medications affecting coagulation.
Physical Examination:
Comprehensive abdominal examination, including inspection for ecchymosis, palpation for tenderness and masses, auscultation for bowel sounds, and percussion
Assessment of hemodynamic status (BP, pulse, capillary refill)
Back and flank examination for tenderness or bruising
Pelvic examination if indicated.
Investigations:
Computed Tomography (CT) angiography is the gold standard for diagnosis, delineating the hematoma size, location, and identifying the source of bleeding, especially vascular injuries
Contrast-enhanced CT is essential for visualizing vascular anatomy
FAST (Focused Assessment with Sonography for Trauma) can be a rapid bedside tool in unstable patients but has lower sensitivity for retroperitoneal bleeding
Laboratory investigations include complete blood count (CBC), coagulation profile (PT/INR, aPTT), and cross-matching for blood products.
Differential Diagnosis:
Other causes of acute abdomen: Mesenteric ischemia
Bowel perforation
Pancreatitis
Ruptured abdominal aortic aneurysm (AAA)
Pelvic hematoma
Solid organ injury
Kidney injury.
Management
Initial Management:
Immediate hemodynamic resuscitation: Airway, breathing, circulation
Aggressive fluid resuscitation with crystalloids and colloids
Blood product transfusion (packed red blood cells, fresh frozen plasma, platelets) according to Massive Transfusion Protocol
Hemodynamic monitoring
Consultation with trauma surgery and interventional radiology.
Medical Management:
Correction of coagulopathy if present
Reversal of anticoagulation if indicated and safe
Blood pressure management – permissive hypotension in trauma until bleeding source is controlled.
Surgical Management:
Surgical exploration is typically indicated for hemodynamically unstable patients with RPH, expanding hematomas on serial imaging, or when the bleeding source cannot be controlled by interventional radiology
The approach depends on the location and suspected cause of bleeding
For Zone II, a midline laparotomy is often preferred to provide access to both sides of the retroperitoneum and major vessels
Ligation or repair of injured vessels is the primary goal
Careful dissection is required to avoid further injury
Placement of hemostatic agents may be necessary
Preoperative embolization by interventional radiology can sometimes stabilize the patient for surgery.
Supportive Care:
Intensive care unit (ICU) monitoring post-operatively
Pain management
Nutritional support
Deep vein thrombosis (DVT) prophylaxis
Monitoring of urine output and renal function
Strict fluid balance.
Complications
Early Complications:
Hemorrhagic shock
Organ ischemia due to vascular compromise
Acute kidney injury
Sepsis
Fasciitis
Rebleeding.
Late Complications:
Chronic pain
Adhesions
Bowel obstruction
Pseudoaneurysm formation
Vascular stenosis
Chronic fluid collections or seromas.
Prevention Strategies:
Careful surgical technique during vascular access or procedures
Prompt recognition and management of iatrogenic injuries
Aggressive resuscitation to maintain hemodynamic stability
Judicious use of anticoagulants
Close monitoring of patients at high risk.
Prognosis
Factors Affecting Prognosis:
The patient's hemodynamic stability at presentation
The extent and source of bleeding
The presence of concomitant injuries
Timeliness of diagnosis and intervention
Availability of blood products and surgical expertise.
Outcomes:
Mortality rates for Zone II RPH can be high, particularly in hemodynamically unstable patients
Survival is significantly improved with rapid resuscitation and definitive control of hemorrhage
Long-term morbidity can include chronic pain and functional limitations.
Follow Up:
Close monitoring of vital signs and fluid balance
Serial imaging if concerned about rebleeding or complications
Long-term follow-up may be required for vascular surveillance if significant arterial injury was repaired.
Key Points
Exam Focus:
Zone II RPH involves the anterior pararenal and perirenal spaces
CT angiography is the investigation of choice
Hemodynamic instability dictates urgent surgical exploration
Midline laparotomy is often the preferred approach for Zone II exploration
Permissive hypotension is a key concept in managing trauma patients with bleeding.
Clinical Pearls:
Always consider RPH in hypotensive trauma patients, even without obvious abdominal signs
Do not be afraid to explore a large, expanding retroperitoneal hematoma in an unstable patient
Remember the major vascular structures (aorta, vena cava, renal vessels) are in close proximity in Zone II
Preoperative embolization can be a life-saving bridge to surgery.
Common Mistakes:
Delaying surgical exploration in hemodynamically unstable patients
Inadequate resuscitation prior to surgery
Insufficient visualization of the bleeding source due to poor surgical exposure or inadequate imaging
Overlooking concomitant injuries
Aggressive blood pressure management in the initial phase of shock leading to rebleeding.