What is the approach for hybrid arch repair in patients with aortic arch disease?

Hybrid Arch Repair Techniques

In patients with aortic arch aneurysms who meet criteria for intervention but have high surgical risk, hybrid arch repair combining supra-aortic debranching with thoracic endovascular aortic repair (TEVAR) may be considered as an alternative to open surgical replacement. 1

Patient Selection for Hybrid Approach

Hybrid arch repair is specifically indicated for:

• High-risk surgical candidates who meet intervention criteria (arch diameter ≥55 mm) but cannot tolerate conventional open repair due to advanced age, significant comorbidities, or prohibitive operative risk 1
• Patients with extensive aneurysmal disease involving both the aortic arch and descending thoracic aorta, where a two-stage approach is generally required 2
• Contraindication: Hybrid/endovascular techniques should be avoided in patients with genetically mediated aortic disorders (Marfan syndrome, Loeys-Dietz syndrome), where open repair remains the standard 1

Classification and Technical Approaches

The hybrid arch repair classification system defines three main types based on the extent of reconstruction required 3, 4:

Type I Hybrid Repair

• Technique: Aortic arch vessel debranching with revascularization via median sternotomy, followed by endovascular stent deployment in the ascending aorta 5
• Landing zone: Created in the native ascending aorta (Zone 0) 5
• Cardiopulmonary bypass: Required, but deep hypothermic circulatory arrest typically avoided 5

Type II Hybrid Repair

• Technique: Ascending aorta and transverse arch replacement with arch vessel debranching, followed by concomitant antegrade stent grafting of the aortic arch 5, 4
• Landing zone: Created on the reconstructed ascending aorta and arch 4
• Cardiopulmonary bypass: Required with potential need for deep hypothermic circulatory arrest 5, 4

Type III Hybrid Repair

• Technique: Isolated arch vessel debranching without ascending aortic replacement 3

Critical Technical Considerations

Proximal Landing Zone Reinforcement

• Dacron prosthesis reinforcement of the proximal aortic arch at the landing zone is essential to prevent type I endoleak, which remains the primary technical complication 6
• A minimum landing zone length of 3.8 cm has been demonstrated to reduce early endoleak risk 6

Staged vs. Concomitant Approach

• Two-stage approach: Supra-aortic debranching performed first, followed by delayed endovascular stent grafting (mean interval 32 days) 6, 7
• Single-stage approach: Concomitant debranching and stent deployment in the same operation 4
• For extensive disease involving arch and descending aorta, the two-stage approach is standard, with the first stage creating the landing zone and the second stage completing endovascular repair 2

Expected Outcomes and Complications

Perioperative Results

• Mortality: 10-11% in high-risk cohorts 5, 7
• Stroke: 11-12% 5, 7
• Spinal cord ischemia/paraplegia: 6-7% 5, 7
• Type I endoleak: 16% without landing zone reinforcement 7

Mid-term Outcomes

• Survival at 48 months: 73% 7
• Bypass graft patency: High rates with minimal late occlusion after the perioperative period 7
• Reintervention rate: Low (approximately 6%) for endoleak management 7

Critical Pitfalls to Avoid

• Inadequate landing zone length: Ensure minimum 3.8 cm landing zone to prevent type I endoleak 6
• Failure to reinforce landing zone: Proximal arch reinforcement with Dacron prosthesis significantly reduces endoleak risk 6
• Retrograde dissection: Occurs in approximately 6% of cases, requiring emergency aortic root repair or innominate stenting 7
• Incomplete second-stage procedure: In two-stage repairs, failure to complete the endovascular component leaves patients at high risk for rupture, dissection, or ischemic events 2

Comparison to Open Repair

While open surgical replacement remains the gold standard for low-risk patients with isolated arch aneurysms at diameter ≥55 mm 1, hybrid techniques offer:

• Reduced perioperative morbidity compared to conventional total arch replacement requiring deep hypothermic circulatory arrest 3
• Comparable outcomes to open surgery in appropriately selected high-risk patients 3, 7
• Acceptable short and mid-term results, though long-term data beyond 5 years remain limited 3, 7

The decision between open and hybrid approaches must be made by a surgical team with expertise in both techniques, as hybrid repair represents an off-label application of approved endograft technology 3.