Overview
Definition:
Massive hemorrhage control refers to immediate interventions to stop life-threatening bleeding
Aortic occlusion is a critical temporizing measure used to reduce distal blood flow and allow for resuscitation and definitive hemorrhage control, often in cases of severe truncal or lower extremity trauma
It aims to increase proximal aortic pressure, perfuse vital organs, and facilitate surgical repair.
Epidemiology:
Hemorrhagic shock remains a leading cause of preventable death in trauma, accounting for approximately 40% of all trauma deaths
Massive hemorrhage can occur from blunt or penetrating injuries to the torso, pelvis, and extremities
The use of aortic occlusion techniques is indicated in patients with refractory shock despite initial resuscitation efforts.
Clinical Significance:
Effective hemorrhage control and resuscitation are paramount in saving lives following severe trauma
Aortic occlusion, whether via REBOA or direct clamping, provides a crucial window to stabilize the patient, allowing for definitive source control of bleeding, reducing the need for prolonged hypotension, and improving outcomes in critically injured patients
Understanding the indications, contraindications, and techniques for each method is vital for trauma surgeons and residents preparing for DNB and NEET SS examinations.
Indications And Contraindications
Indications:
Resuscitation-refractory shock (systolic blood pressure < 90 mmHg despite adequate fluid resuscitation and blood products)
Significant torso or proximal extremity hemorrhage
Use as a bridge to definitive hemorrhage control (e.g., laparotomy, thoracotomy, pelvic packing)
Patients with severe coagulopathy
Initial resuscitation failing to restore adequate hemodynamics.
Contraindications:
Severe head injury with GCS < 3
Known unreconstructable aortic transection or dissection
Active bleeding from the head, neck, or chest above the occlusion zone
Patient expected to survive less than 30 minutes even with occlusion
Prolonged ischemic time > 30 minutes may lead to organ damage
Severe thoracic trauma precluding chest compressions
Blunt aortic injury with suspected mediastinal hematoma.
Aortic Occlusion Methods
Direct Aortic Clamping:
Open surgical technique involving direct visualization and clamping of the aorta, typically in the supra-diaphragmatic or infra-diaphragmatic region during laparotomy or thoracotomy
Requires immediate surgical access and operative field
Provides definitive control but necessitates a formal surgical approach.
Reboa Percutaneous Aortic Occlusion:
Resuscitation Endovascular Balloon Occlusion of the Aorta
A less invasive endovascular technique utilizing a specialized balloon catheter inserted percutaneously (usually via femoral artery) into the aorta
Inflation of the balloon occludes aortic flow
Allows for placement in the ER or ICU, providing rapid temporizing control before definitive surgery
Different zones of occlusion (Zone I: infra-renal, Zone II: supra-celiac, Zone III: infra-renal) are described with varying clinical implications.
Comparison Of Methods
Timing Of Placement:
REBOA can be placed rapidly in the pre-hospital setting, ER, or ICU
direct clamping requires the patient to be in the OR and surgically exposed.
Invasiveness:
REBOA is less invasive, performed percutaneously
direct clamping is invasive, requiring a surgical incision.
Scope Of Application:
REBOA can be used as a temporizing measure to facilitate transport or further resuscitation before definitive surgery
direct clamping is part of definitive surgical management but can also be used in emergent situations.
Complication Profile:
REBOA associated with limb ischemia, access site complications, systemic embolization
direct clamping associated with visceral ischemia, spinal cord ischemia (if prolonged), perioperative bleeding, and organ damage from sudden pressure changes.
Skill Set Required:
REBOA requires interventional radiology or endovascular surgery skills
direct clamping requires general surgical operative skills.
Management Considerations
Decision Making:
Choice depends on patient stability, available resources, expertise, and the nature of the hemorrhage
For patients requiring immediate transfer or stabilization before surgery, REBOA may be preferred
In a fully equipped OR with a surgeon ready for definitive control, direct clamping might be the primary choice.
Reboa Placement Technique:
Access the common femoral artery
Advance the guidewire and sheath
Insert the REBOA catheter
Inflate the balloon under guidance (e.g., ultrasound or fluoroscopy) to achieve appropriate occlusion
Monitor hemodynamics closely
For Zone I REBOA, inflation is distal to renal arteries
For Zone II, between the subclavian and celiac arteries
For Zone III, infra-renal.
Direct Clamping Technique:
Requires surgical exploration (laparotomy or thoracotomy)
Identify the aorta proximal to the bleeding source
Apply a vascular clamp judiciously to achieve hemostasis without causing undue injury
Manage distal perfusion and avoid prolonged ischemia.
Post Occlusion Care:
Close monitoring of vital signs, urine output, and end-organ perfusion
Gradual deflation of the REBOA balloon or release of the clamp to avoid reperfusion injury and sudden hemodynamic collapse
Definitive surgical repair of the bleeding source must be performed as soon as the patient is stable enough
Consider anticoagulation or thrombolysis if embolic complications are suspected after REBOA.
Complications
Reboa Complications:
Ischemia of lower extremities, abdominal organs, or spinal cord
Access site bleeding, hematoma, or pseudoaneurysm
Distal embolization
Reperfusion injury
Aortic rupture or dissection
End-organ damage due to prolonged ischemia or sudden reperfusion.
Direct Clamping Complications:
Visceral ischemia, renal failure, mesenteric ischemia, and spinal cord ischemia (especially with thoracic aortic clamping)
Perioperative bleeding
Graft infection or dehiscence if reconstruction is performed
Myocardial stunning or failure due to increased afterload.
Prevention And Mitigation:
Use of REBOA for the shortest effective duration
Careful balloon inflation and deflation protocols
Close hemodynamic monitoring
Judicious use of anticoagulation if indicated
Prompt definitive surgical intervention
Adequate resuscitation and organ support
Intraoperative neuromonitoring for spinal cord protection when appropriate.
Key Points
Exam Focus:
Understand the hemodynamic effects of aortic occlusion
Differentiate indications and contraindications for REBOA vs
direct clamping
Recall zones of REBOA and their implications
Be aware of potential complications for both methods.
Clinical Pearls:
REBOA is a temporizing measure
definitive surgical control is always required
Balloon inflation should be gradual, and deflation slow to avoid profound hypotension
In trauma, consider REBOA early in refractory shock
Always assess for distal pulses and neurological status after REBOA placement.
Common Mistakes:
Over-reliance on REBOA without planning for definitive surgery
Prolonged occlusion times leading to ischemic damage
Incorrect balloon inflation or deflation
Failure to adequately resuscitate post-occlusion
Not considering the risk of spinal cord ischemia with thoracic aortic clamping.