Mid-term Results of Hybrid Arch Repair for DeBakey Type I Aortic Dissection
Aortic dissection, particularly DeBakey type I, presents a critical challenge in cardiovascular surgery due to its high mortality and morbidity. Traditional total aortic arch replacement (TAR) combined with the frozen elephant trunk (FET) technique has been a standard approach. However, this method is associated with prolonged operative times, deep hypothermic circulatory arrest (DHCA), and significant risks of neurological and systemic complications. In contrast, hybrid aortic repair techniques, integrating open surgical graft replacement with endovascular stent deployment, have emerged as a less invasive alternative. This study evaluates the mid-term safety and efficacy of hybrid TAR compared to conventional FET for treating DeBakey type I aortic dissection, leveraging a large patient cohort to address existing gaps in clinical evidence.
Study Design and Patient Population
Conducted at Fuwai Hospital between 2010 and 2016, this retrospective analysis included 937 patients undergoing surgical intervention for DeBakey type I dissection. Patients were stratified into two groups: the FET group (n = 815, 86.9%) and the hybrid TAR group (n = 122, 13.1%). Exclusion criteria for hybrid repair included age <50 years and severe true lumen compression in the descending aorta. To minimize selection bias, 109 matched pairs were generated via propensity scoring, accounting for baseline characteristics such as age, malperfusion status, and aortic valve insufficiency.
Surgical Techniques
FET Group
Under DHCA, the aortic arch was transected proximal to the left subclavian artery. The FET stent graft was deployed into the true lumen of the descending aorta under direct vision. A tetrafurcated graft was anastomosed to the aortic arch, incorporating the FET stent. Sequential anastomoses reconstructed the innominate, left carotid, and left subclavian arteries, followed by proximal graft-to-ascending aorta connection (Figure 1A).
Hybrid Group
Moderate hypothermia (28°C nasopharyngeal temperature) was used instead of DHCA. The aortic arch was replaced with a tetrafurcated graft, with branches anastomosed to the innominate, left carotid, and left subclavian arteries. Post-cardiopulmonary bypass (CPB), a stent graft was deployed retrograde into the descending aorta, anchored proximally to the artificial graft (Figure 1B). This approach avoided DHCA and reduced CPB duration.
Early Outcomes
The hybrid group demonstrated significant advantages in operative efficiency. CPB time (145.2 ± 32.1 vs. 212.8 ± 45.6 minutes, P < 0.001) and aortic cross-clamp time (89.4 ± 21.3 vs. 134.5 ± 29.7 minutes, P < 0.001) were markedly shorter compared to the FET group. Early mortality rates were comparable (hybrid: 9.0% vs. FET: 10.7%, P = 0.577). However, the hybrid group exhibited lower rates of acute kidney injury (3.3% vs. 9.5%, P = 0.013) and liver dysfunction (1.6% vs. 6.4%, P = 0.022). Notably, no spinal cord injuries occurred in the hybrid cohort, contrasting with a 2.5% incidence in the FET group (P = 0.014).
Mid-term Follow-up
Over a mean follow-up of 36.8 months (range: 12–84 months), survival rates at 1, 3, and 5 years were 87.9%, 86.3%, and 82.2% for hybrid repair versus 80.7%, 76.9%, and 74.6% for FET (P = 0.086). While statistically non-significant, the trend favored hybrid repair. Reintervention rates were comparable: 3.6% (28/778) overall, with thoracoabdominal replacement being most common (76% of FET reoperations). Hybrid cases required fewer aortic reoperations, primarily limited to proximal repairs.
Technical Considerations and Complications
Hybrid TAR eliminated native aortic zone 0 stent placement, theoretically reducing retrograde dissection risk. However, type Ia endoleaks occurred in 9 hybrid patients (7.4%), resolving spontaneously within 3 months. Stent characteristics—mean diameter 30.3 ± 6.4 mm and length 190.5 ± 25.5 mm—exceeded FET dimensions, yet paradoxically, hybrid procedures showed lower spinal ischemia risk. This may relate to reduced DHCA exposure and blood product utilization.
Clinical Implications
The hybrid approach offers several advantages:
- Avoidance of DHCA: By utilizing moderate hypothermia, hybrid repair circumvents DHCA-associated coagulopathy and neurological risks.
- Reduced CPB Duration: Shorter CPB times correlate with lower systemic inflammatory response and end-organ damage.
- Enhanced Descending Aorta Remodeling: Longer stent coverage (mean 190 mm vs. 120 mm in FET) promoted false lumen thrombosis without increasing spinal ischemia.
- Adaptability for High-Risk Patients: Older patients (mean age 61.3 vs. 46.7 years) tolerated hybrid repair despite higher baseline risk profiles.
Limitations and Future Directions
While mid-term outcomes are encouraging, long-term data beyond 5 years remain essential. Type Ia endoleaks, though self-limiting in this cohort, warrant vigilance. Additionally, hybrid techniques require advanced endovascular expertise and intraoperative imaging. Future studies should assess cost-effectiveness and quality-of-life metrics.
Conclusion
Hybrid arch repair demonstrates comparable early mortality and superior mid-term survival trends relative to conventional FET for DeBakey type I dissection. By minimizing DHCA and CPB duration, it reduces neurological and visceral complications while achieving adequate aortic remodeling. These results position hybrid TAR as a viable alternative, particularly for older patients and those unsuitable for prolonged DHCA.
doi.org/10.1097/CM9.0000000000001556
Was this helpful?
0 / 0