Treatment Approach for Type A and Type B Aortic Dissections
Type A aortic dissections require immediate emergency surgical intervention, while uncomplicated Type B dissections are primarily managed medically with close monitoring, reserving intervention for complications or disease progression. 1, 2
Type A Aortic Dissection Management
Immediate Surgical Intervention
- Emergency surgery is mandatory to prevent fatal complications including:
- Mortality reaches 50% within first 48 hours without surgery 1
- Surgery reduces 1-month mortality from 90% to 30% 1
Surgical Approach
- Access: Median sternotomy with extracorporeal circulation via femoral artery and right atrium cannulation 1, 2
- Repair options based on aortic root size and valve condition:
- Normal aortic root with normal valve: Valve-preserving surgery with tubular graft anastomosed to sinotubular ridge 1
- Detached valve commissures: Valve resuspension prior to graft insertion 1
- Ectatic proximal aorta or pathological valve: Composite graft (aortic valve plus ascending aortic tube graft) 1
- Marfan syndrome patients: Valve preservation and aortic root remodeling when possible 1
Extent of Repair Considerations
- Preferable to replace aortic root if dissection involves sinus of Valsalva 1
- Supracoronary ascending aorta replacement alone risks late dilation and recurrent aortic regurgitation 1
- "Frozen elephant trunk" repair may benefit patients with visceral/renal malperfusion 1
- Intraoperative aortoscopy and immediate post-operative imaging recommended 1
Special Considerations
- Age alone should not exclude surgical treatment 1
- Coronary artery involvement requires concomitant coronary artery bypass grafting 3
Type B Aortic Dissection Management
Uncomplicated Type B Dissection
Complicated Type B Dissection
- Intervention indicated for:
Intervention Options for Complicated Type B
TEVAR (Thoracic Endovascular Aortic Repair) is first-line therapy 2, 4:
- Lower perioperative morbidity and mortality
- Reduced risk of spinal cord ischemia
- Shorter hospital stays
- Induces aortic remodeling by redirecting blood flow to true lumen 1
- Extended follow-up shows reduced aorta-related mortality (6.9% vs 19.3%) and disease progression (27% vs 46.1%) compared to medical therapy alone 1
Open surgical repair considered for:
- Young patients with connective tissue disorders
- Anatomy unsuitable for endovascular repair 2
Post-Intervention Monitoring
- Imaging recommended:
- Within 1 month post-procedure
- Every 6 months for first year
- Annually thereafter 2
- Lifelong blood pressure control with beta-blockers 2
- Monitor for false lumen status, endoleaks, and expansion of residual dissection 2
Important Pitfalls and Caveats
Delayed diagnosis of Type A dissection is fatal - maintain high index of suspicion in patients with sudden-onset chest pain, especially with hypertension history
Malperfusion syndromes can be overlooked despite stable hemodynamics - thorough assessment for end-organ perfusion is critical 2
Inadequate blood pressure control is the most common cause of dissection extension 2
Distal reentry phenomenon into abdominal aorta may lead to AAA development and late rupture despite adequate thoracic repair 4
Aneurysm formation at stent ends requires vigilant follow-up imaging 4
Residual dissection after Type A repair may require additional intervention during follow-up 5
Coronary involvement in Type A dissection significantly increases mortality - requires immediate recognition and concomitant coronary bypass 3