Aortic arch repair: What is the frozen elephant trunk repair procedure?

The frozen elephant trunk (FET) repair is a surgical technique used to treat complex diseases of the aortic arch, the part of the heart’s aorta that assists in the distribution of blood to the head and upper extremities, and descending thoracic aorta. These diseases include aneurysms, dissections or other severe aortic pathologies. It combines both open and endovascular (minimally invasive) approaches into one operation, enabling the treatment of two parts of the aorta during the same procedure.

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How does the FET procedure work?

1. Open surgical component:
   The surgeon performs a median sternotomy (opening of the chest) and replaces the diseased aortic arch with a synthetic graft. This part of the procedure requires cardiopulmonary bypass (a heart-lung machine) and often involves hypothermic circulatory arrest (lowering the body temperature to protect the brain and organs while temporarily stopping blood circulation).

2. Frozen elephant trunk (hybrid prosthesis):
   A specialised hybrid graft is used. The "frozen" part refers to the endovascular stent graft (similar to those used in less invasive aortic repairs) that is attached to the distal end of the synthetic graft. The stent portion is deployed into the descending thoracic aorta, extending beyond the aortic arch into the diseased segment of the descending aorta. This stabilises the descending aorta and excludes the diseased area from blood flow.

What are the advantages of the FET procedure?

• Comprehensive repair: Treats both the aortic arch and the descending thoracic aorta in a single operation.
• Reduced need for subsequent procedures: The stent graft component reduces the need for additional surgeries or interventions.
• Minimally invasive extension: The endovascular stent graft provides less invasive treatment for the descending aorta compared to a traditional open repair.
• Facilitates further interventions: If required, additional procedures on the descending aorta (such as stent graft extensions) can be performed later with less complexity.

When is it used?

The FET procedure is typically used in patients with:

• Extensive thoracic aortic aneurysms.
• Type A or Type B aortic dissections involving the aortic arch and descending thoracic aorta.
• Chronic aortic diseases where both the arch and descending aorta are diseased.
• Connective tissue disorders like Marfan syndrome, where the entire aorta may require stabilisation.

What are the risks and considerations of the FET procedure?

As a highly complex procedure, the FET repair carries significant risks, including bleeding, stroke, spinal cord injury (leading to paralysis in rare cases), infection and complications related to the heart-lung machine. However, in experienced centres and for carefully selected patients, it can significantly improve long-term outcomes.

The FET repair represents an advanced and innovative approach in the field of aortic surgery, providing a durable solution for complex aortic diseases.