What is the recommended treatment for a patient with a stable chronic type B Stanford thoracic aortic dissection of more than 10 years duration, with a stable size of the false lumen and no evidence of organ malperfusion?

Management of Stable Chronic Type B Aortic Dissection (>10 Years Duration)

For a patient with a stable chronic type B aortic dissection of more than 10 years duration, with stable false lumen size and no organ malperfusion, medical management with antihypertensive therapy and annual surveillance imaging is recommended, with intervention reserved only if the descending thoracic aortic diameter reaches ≥60 mm or if complications develop. 1

Medical Management: The Foundation of Treatment

Blood Pressure Control

• Antihypertensive therapy is mandatory (Class I recommendation) for all patients with chronic type B aortic dissection. 1
• Target systolic blood pressure <120 mmHg with beta-blockers as first-line agents to reduce aortic wall stress. 2
• Beta-blockers should be considered as first-line medical therapy to control heart rate and reduce hemodynamic stress on the aortic wall. 1
• Never use vasodilators without prior beta-blockade, as reflex tachycardia increases aortic wall stress. 3
• Most patients require combination antihypertensive therapy to achieve adequate blood pressure control. 3

Cardiovascular Risk Factor Management

• Aggressive management of all cardiovascular risk factors is essential to slow disease progression. 3
• Statin therapy may improve survival in patients with aortic dissection under medical treatment. 1
• Moderate restriction of physical activity is recommended to minimize aortic wall stress. 1

Surveillance Imaging Strategy

Imaging Schedule for Stable Chronic Dissection

• For medically managed chronic type B dissection with stable anatomy over 10 years, annual imaging surveillance is recommended. 1
• The 2024 ESC guidelines recommend imaging at 1,3,6, and 12 months after initial diagnosis, then yearly thereafter if stable. 1
• Given this patient's 10-year stability, annual imaging is sufficient unless concerning features develop. 1

Imaging Modality Selection

• MRI is the preferred imaging modality for serial follow-up, as it avoids ionizing radiation and nephrotoxic contrast while providing excellent visualization of the entire aorta. 3
• CT angiography is an acceptable alternative, particularly in patients over 60 years where radiation exposure is less concerning. 3
• Imaging should assess aortic diameter, false lumen patency, and any signs of complications. 2

Indications for Intervention

Size-Based Criteria

• In patients with chronic type B dissection and descending thoracic aortic diameter ≥60 mm, treatment is recommended in patients at reasonable surgical risk (Class I recommendation). 1
• For patients with descending thoracic aortic diameter ≥55 mm, intervention should be considered in patients with low procedural risk (Class IIa recommendation). 1
• Since this patient has a stable false lumen size over 10 years, intervention is not indicated unless these diameter thresholds are reached. 1

Complication-Based Criteria

• Emergency intervention is recommended if the patient develops acute symptoms of malperfusion, rupture, or progression of disease (Class I recommendation). 1
• Development of uncontrolled hypertension despite medical therapy is a high-risk feature requiring reassessment. 2
• Rapid aortic growth (>3 mm/year for descending aorta) warrants consideration of intervention. 2

Endovascular vs. Open Repair

• When intervention is indicated and anatomy is suitable, TEVAR is recommended over open surgery for chronic type B dissection. 3
• In patients with chronic post-dissection thoracoabdominal aortic aneurysms, fenestrated/branched stent grafts may be considered when treatment is indicated (Class IIb recommendation). 1

Critical Pitfalls to Avoid

False Lumen Assessment

• A patent false lumen with active flow is a predictor of progressive dilatation and rupture, even in chronic dissections. 2
• Patency of the false lumen is an independent risk factor for dissection-related death and events. 4
• Complete thrombosis of the false lumen appears to be a prerequisite for complete healing and carries better prognosis. 1

Monitoring for Late Complications

• Approximately 40% of chronic type B dissection patients eventually require intervention due to aortic dilatation reaching 55 mm. 1
• The dissected aorta grows at approximately 1 mm per year on average. 1
• Around 10% of patients develop complications requiring reoperation during long-term follow-up. 1

Anticoagulation Considerations

• If anticoagulation becomes necessary for another indication (e.g., atrial fibrillation), obtain dedicated aortic imaging first to fully characterize current dissection status. 2
• Aortic diameter approaching 6.0 cm is a high-risk feature that would preclude anticoagulation due to rupture risk. 2
• If anticoagulation is absolutely necessary, warfarin with tight INR control (2.0-3.0) may be preferable to DOACs, and more frequent imaging surveillance (every 3-6 months) is required. 2

Long-Term Prognosis

• Patients with chronic type B dissection who remain stable on medical therapy have favorable long-term outcomes if the false lumen is thrombosed and aortic diameter remains <55 mm. 4
• The 10-year freedom from aortic enlargement (≥55 mm) for patients with maximum diameter <45 mm and thrombosed false lumen is approximately 89%. 4
• Continued surveillance is mandatory even in stable patients, as late complications can occur after many years. 1, 3