What are the surgical indications for a descending pseudoaneurysm in the descending thoracic aorta?

Surgical Indications for Descending Thoracic Aortic Pseudoaneurysms

For patients with descending thoracic aortic pseudoaneurysms, endovascular stent grafting should be strongly considered as the first-line intervention regardless of size, as pseudoaneurysms always require intervention due to their high risk of rupture. 1

Definition and Risk

• Aortic pseudoaneurysm (false aneurysm) is defined as a dilation of the aorta due to disruption of all wall layers, which is only contained by periaortic connective tissue 1
• When the pressure of the pseudoaneurysm exceeds the maximally tolerated wall tension of the surrounding tissue, fatal rupture occurs 1
• Other life-threatening complications include fistula formation and compression or erosion of surrounding structures 1

Specific Indications for Intervention

• All pseudoaneurysms require intervention regardless of size due to their inherent instability and high risk of rupture 1
• Symptomatic pseudoaneurysms (chest pain, dysphagia, dyspnea, cough, hoarseness) require immediate intervention 1, 2
• Signs of contained rupture (rapidly growing aortic ulcer, associated periaortic hematoma, pleural effusion) necessitate urgent intervention 1
• Recurrent or refractory pain in patients with pseudoaneurysms identifies those at highest risk of rupture 1

Treatment Approach Selection

Endovascular Approach (Preferred)

• Endovascular stent grafting should be strongly considered when anatomically feasible (Class I recommendation, Level of Evidence B) 1
• Particularly valuable for patients with significant comorbidities (advanced age, cardiac, pulmonary, or renal dysfunction) 1
• Benefits include:
  • Absence of thoracotomy incision 1
  • No need for partial or total extracorporeal circulatory support 1
  • Lower hospital morbidity rates and shorter length of hospital stay 1, 3

Contraindications to Endovascular Approach

• Absence of suitable "landing zones" above and below the aneurysm (usually 2-3 cm of normal diameter aorta without circumferential thrombus) 1
• Aortic diameter at landing zones exceeding recommendations for largest available endovascular grafts 1
• Lack of vascular access sites for large-bore sheaths 1
• Severe atherosclerosis and intraluminal thrombus (relative contraindication due to embolic stroke risk) 1

Open Surgical Approach

• Indicated when endovascular repair is not technically feasible 1
• May be necessary for patients with connective tissue disorders like Marfan syndrome 1
• Required when there is compression of vital structures that won't be relieved by endovascular repair 4

Complications to Monitor

• Endovascular-specific complications: endoleak, graft migration, stent fracture, and mechanical damage to access artery and aortic wall 3
• General complications: paraplegia (2.2%), stroke (3.9%), cardiac events (2.9%), respiratory failure (8.7%), renal failure (2.8%), and intestinal ischemia (1%) 3

Special Considerations

• Pseudoaneurysms following trauma or iatrogenic causes (e.g., previous aortic surgery) may have different anatomical considerations that affect treatment choice 1, 5
• For infected pseudoaneurysms (mycotic aneurysms), additional antimicrobial therapy is essential alongside intervention 1, 6
• Careful imaging assessment with CT angiography and/or MRI is crucial for proper planning of intervention 1

Follow-up After Treatment

• Regular imaging surveillance is essential following repair to detect potential complications 4
• Recommended follow-up includes chest spiral angio-CT scan within 72 hours post-procedure and then at 6 and 12 months, followed by annual imaging 4