Endovascular treatment of arterial aneurysm /pseudoaneurysm

Endovascular treatment of arterial aneurysms and pseudoaneurysms involves minimally invasive techniques to repair or exclude the aneurysmal sac from the circulation, reducing the risk of rupture and associated complications. This approach is often preferred over open surgery due to its lower morbidity and faster recovery times.

Types of Arterial Aneurysms

• True Aneurysms: Involve all three layers of the arterial wall (intima, media, and adventitia) (Click here to read more on Aortic Aneurysm) (Click here to read more on Visceral Arterial Aneurysm)
• Pseudoaneurysms (False Aneurysms): Result from a breach in the arterial wall, with blood contained by the surrounding tissue rather than the vessel wall (Click here to read more on Arterial Pseudoaneurysm)

Endovascular Treatment Options

1. Stent Grafts:
   • Mechanism: A stent graft is a tube covered with fabric (graft material) that is placed inside the aneurysmal artery to create a new pathway for blood flow, thereby excluding the aneurysm from the circulation.
   • Procedure:
     • Access: Usually via the femoral artery, though brachial or radial access can be used in some cases.
     • Navigation: The stent graft is advanced over a guidewire to the site of the aneurysm under fluoroscopic guidance.
     • Deployment: The stent graft is carefully positioned and deployed, expanding to conform to the artery’s diameter and sealing the aneurysm.
2. Coil Embolization:
   • Mechanism: Coils are placed within the aneurysm sac to promote clotting and fibrosis, effectively excluding the aneurysm from blood flow.
   • Procedure:
     • Access: Typically through the femoral artery.
     • Microcatheter Navigation: A microcatheter is navigated into the aneurysm sac.
     • Coil Deployment: Coils are deployed into the aneurysm, filling the sac and inducing thrombosis.
3. Flow Diverters:
   • Mechanism: These are specialized stents that redirect blood flow away from the aneurysm, promoting thrombosis within the aneurysm.
   • Procedure:
     • Access and Navigation: Similar to stent graft placement.
     • Deployment: The flow diverter is deployed across the aneurysm neck, diverting blood flow away from the aneurysm and allowing it to clot.

Procedure Steps

1. Pre-procedure Preparation:
   • Imaging: CT angiography (CTA), MR angiography (MRA), or conventional angiography to assess the anatomy and plan the procedure.
   • Anesthesia: Local anesthesia with sedation or general anesthesia, depending on the complexity and patient condition.
2. Access and Navigation:
   • Vascular Access: Insertion of a sheath into the chosen access artery (commonly femoral).
   • Guidewire and Catheter Navigation: Advancement of guidewires and catheters to the aneurysm site under fluoroscopic guidance.
3. Aneurysm Exclusion:
   • Stent Graft Deployment: Careful positioning and deployment of the stent graft to seal the aneurysm.
   • Coil Embolization: Insertion and deployment of coils into the aneurysm sac to promote clotting.
   • Flow Diverter Deployment: Placement of the flow diverter to redirect blood flow away from the aneurysm.
4. Post-procedure Care:
   • Hemostasis: Achieved by manual compression or vascular closure devices at the access site.
   • Monitoring: Close monitoring for complications such as bleeding, vessel injury, or endoleaks (persistent blood flow into the aneurysm sac post-stent graft placement).
   • Medications: Antiplatelet or anticoagulant therapy as indicated to prevent thrombotic events.

Indications

• Aneurysms at risk of rupture or those causing symptoms.
• Pseudoaneurysms resulting from trauma, infection, or iatrogenic causes.
• Aneurysms in locations amenable to endovascular repair (e.g., abdominal aorta, thoracic aorta, peripheral arteries).

Contraindications

• Inability to obtain adequate vascular access.
• Severe vessel tortuosity preventing safe navigation of devices.
• Active infection at the planned access site.
• Patient conditions that preclude the use of contrast agents or sedation/anesthesia.

Benefits

• Minimally invasive with shorter recovery times compared to open surgery.
• Reduced blood loss and lower risk of infection.
• Suitable for high-risk patients who may not tolerate open surgery.

Risks

• Endoleaks (persistent blood flow into the aneurysm sac).
• Vascular complications such as dissection, perforation, or access site hematomas.
• Device migration or malposition.
• Thrombosis or embolization leading to distal ischemia.

Conclusion

Endovascular treatment of arterial aneurysms and pseudoaneurysms is a highly effective and less invasive alternative to open surgery, offering significant benefits in terms of reduced recovery times and complications. The choice of technique—whether stent grafting, coil embolization, or flow diversion—depends on the specific anatomy and characteristics of the aneurysm, as well as the patient’s overall health status. Successful outcomes rely on careful pre-procedure planning, precise execution, and vigilant post-procedure monitoring.