What are the guidelines for repairing a thoracic aortic aneurysm?

From the Guidelines

Thoracic aortic aneurysms should be repaired when they reach 5.5 cm in diameter for most patients, or 5.0 cm for those with genetic conditions like Marfan syndrome, as recommended by the 2022 ACC/AHA guideline for the diagnosis and management of aortic disease 1.

Guidelines for Repair

The guidelines for repairing a thoracic aortic aneurysm prioritize the size of the aneurysm, with a maximum aortic diameter of ≥5.5 cm being the primary criterion for elective surgical repair of aneurysms of the aortic root or ascending thoracic aorta 1.

• For patients with a family history of TAA, aortic dissection, or both, but with no known pathogenic variant, it is useful to determine the size at which the aorta dissected (if known) or the size at which elective aortic surgery was performed, as well as the age of the affected relative at time of the aortic event 1.
• Patients with a family history of TAAs but with no known pathogenic variant may not have information regarding the aneurysm size at which the family members underwent either elective surgery or experienced aortic dissection, and prophylactic surgery is warranted when the maximal diameter of the aortic root or ascending aorta reaches ≥5.0 cm 1.

Surgical Repair

Surgical repair is the standard treatment, involving either open surgery with graft replacement or endovascular repair (TEVAR) using stent grafts.

• Before reaching surgical thresholds, patients should receive medical management including blood pressure control with beta-blockers (such as metoprolol 25-100 mg twice daily) or angiotensin receptor blockers (like losartan 50-100 mg daily), which help reduce hemodynamic stress on the aortic wall 1.
• Regular imaging surveillance is essential, with CT or MRI scans recommended every 6-12 months for aneurysms approaching surgical thresholds and annually for smaller ones 1.

Lifestyle Modifications

Lifestyle modifications are also important, including:

• Smoking cessation
• Moderate exercise avoiding heavy lifting
• Maintaining blood pressure below 130/80 mmHg

Emergency Repair

Emergency repair is necessary for acute complications like rupture or dissection.

• The choice between open surgery and TEVAR depends on aneurysm location, patient age, and comorbidities, with TEVAR generally preferred for elderly or high-risk patients due to lower perioperative mortality despite requiring more frequent long-term surveillance 1.

From the Research

Guidelines for Repairing a Thoracic Aortic Aneurysm

The guidelines for repairing a thoracic aortic aneurysm involve various factors, including the size and location of the aneurysm, as well as the patient's overall health.

• The traditional treatment for thoracic aortic aneurysms (TAA) is open surgical repair, but endovascular stent-graft placement has emerged as a minimally invasive alternative 2.
• Endovascular stent-graft placement involves the use of custom-made or commercially available stent grafts, which are placed in the aorta to exclude the aneurysm from blood flow 2, 3.
• The procedure requires careful consideration of the aneurysm's localization and morphology, as well as the distal vascular access and tortuosity of the aorta 2.
• Studies have shown that endovascular stent-graft placement can be a safe and effective treatment for selected patients with descending TAA, with encouraging short-term results 2, 3.
• However, long-term durability and material fatigue are concerns, and careful follow-up is necessary to manage potential complications 2, 3, 4.

Patient Selection and Preoperative Evaluation

Patient selection and preoperative evaluation are crucial in determining the best course of treatment for thoracic aortic aneurysm.

• Patients with degenerative aneurysms, posttraumatic aneurysms, pseudoaneurysms, and chronic aortic dissections may be candidates for endovascular stent-graft placement 3.
• Preoperative evaluation should include imaging studies such as computed tomography and contrast angiography to assess the aneurysm's size and morphology 3, 5.
• The patient's overall health and comorbidities should also be taken into account, as well as their suitability for open surgical repair or endovascular stent-graft placement 3, 5.

Surgical Techniques and Outcomes

Surgical techniques and outcomes for thoracic aortic aneurysm repair have evolved over time.

• Endovascular stent-graft placement can be performed using custom-made or commercially available stent grafts, with or without preliminary extra-anatomic bypass surgery 3, 4.
• The technical success rate for endovascular stent-graft placement is high, with low early mortality rates 4.
• However, late complications such as aneurysmal expansion, stroke, and paraplegia can occur, and careful follow-up is necessary to manage these complications 2, 3, 4.
• Total endovascular repair of thoracoabdominal aortic aneurysms using non-customized stent grafts and flow-diverting stents is a feasible alternative for high-surgical-risk patients 5.