Overview
Definition:
Hybrid arch debranching with TEVAR (Thoracic Endovascular Aortic Repair) is a complex, staged surgical and endovascular approach to treat extensive aortic arch pathologies
It involves open surgical revascularization of the arch branches (debranching) followed by endovascular repair of the remaining arch and descending aorta with a stent graft.
Epidemiology:
Aortic arch aneurysms and dissections requiring complex repair are relatively uncommon but carry high morbidity and mortality
Patients are often elderly with significant comorbidities, making them unsuitable for conventional open surgical repair.
Clinical Significance:
This hybrid approach expands the treatment options for complex arch disease, particularly in high-risk patients
It aims to reduce the risks associated with extensive open aortic surgery while effectively treating lesions involving the arch and proximal descending aorta, crucial for preventing rupture and stroke.
Indications
Indications For Procedure:
Complex aortic arch aneurysms (fusiform, saccular)
Stanford type B aortic dissections involving the arch
Post-dissection complications like malperfusion or rupture at the arch
Previous aortic arch surgery with recurrent disease
Patients with prohibitive risk for conventional open repair due to age, comorbidities (e.g., severe COPD, cardiac dysfunction, previous sternotomy).
Contraindications:
Unsuitability for any form of aortic intervention
Lack of suitable landing zones for the stent graft
Severe coagulopathy or bleeding diathesis
Active infection
Limited life expectancy from non-aortic disease.
Preoperative Preparation
Patient Assessment:
Comprehensive cardiovascular assessment including coronary angiography
Pulmonary function tests
Renal function assessment
Neurological assessment
Detailed risk stratification (e.g., EuroSCORE II, STS score).
Imaging:
Multidetector CT angiography (MDCTA) is essential to delineate the anatomy of the aortic arch, origin of arch vessels, extent of disease, and to plan both the debranching and TEVAR components
Three-dimensional reconstructions are vital
Transesophageal echocardiography (TEE) may be used intraoperatively.
Arch Vessel Revascularization Strategy:
Planning for bypass grafts from the ascending aorta or descending aorta to the supra-aortic arteries
Common patterns include: 1
Ascending aorta to innominate artery (ICA), left common carotid artery (LCCA), and left subclavian artery (LSCA) – a "three-vessel run-off"
2
Ascending aorta to ICA, LCCA, and LSCA via a trifurcated graft
3
Ascending aorta to ICA, then separate grafts to LCCA and LSCA
4
Direct ascending aorta to arch revascularization
Planning for proximal and distal stent graft landing zones.
Anesthesia Considerations:
General anesthesia with invasive hemodynamic monitoring (arterial line, central venous catheter)
TEE for intraoperative assessment of aortic cannulation and device deployment
Neuromonitoring for spinal cord ischemia.
Procedure Steps
Surgical Debranching:
Median sternotomy or left thoracotomy approach
Exposure of the ascending aorta and/or descending aorta
Graft interposition to revascularize the supra-aortic arteries
Typically involves creating bypasses to the innominate, left common carotid, and left subclavian arteries
Ligation of the proximal left subclavian artery may be performed to facilitate stent graft deployment.
Endovascular Tevar:
After debranching, the arch vessels are typically occluded temporarily
The aortic arch and descending aorta are accessed via femoral or iliac arteries
A stent graft is deployed to cover the diseased segment of the arch and proximal descending aorta
Careful angulation and deployment are crucial to avoid compromising the supra-aortic bypass grafts.
Completion Imaging:
Intraoperative angiography and/or TEE to confirm stent graft position, absence of endoleaks, and patency of the supra-aortic bypass grafts
Assessment of flow through the debranched vessels.
Postoperative Care
Monitoring:
Close hemodynamic monitoring to maintain adequate perfusion pressure
Neurological monitoring for signs of stroke or spinal cord ischemia
Serial imaging (CTA) to assess graft integrity and detect endoleaks
Management of blood pressure is critical to minimize stress on the repair.
Medical Management:
Aggressive blood pressure control (target SBP < 120 mmHg in dissection)
Dual antiplatelet therapy post-TEVAR is standard
Long-term anticoagulation may be considered in select cases
Management of comorbidities.
Complications Management:
Prompt recognition and management of endoleaks, graft migration, stroke, spinal cord ischemia, graft infection, and bleeding
Re-interventions may be necessary.
Complications
Early Complications:
Stroke (most common and significant)
Spinal cord ischemia leading to paraplegia or paraparesis
Bleeding
Graft infection
Access site complications
Myocardial infarction
Acute kidney injury
Endoleaks (Type I, II, III, IV, V)
Graft migration.
Late Complications:
Graft degeneration or dilation
Re-dissection
Late endoleaks
Chronic graft infection
Aortoesophageal fistula
Aortobronchial fistula
Persistent or recurrent symptoms
Need for re-intervention.
Prevention Strategies:
Meticulous patient selection and risk assessment
Precise imaging and planning
Careful surgical technique during debranching
Accurate stent graft sizing and deployment
Optimal intraoperative management
Aggressive postoperative blood pressure and dual antiplatelet therapy
Long-term surveillance with imaging.
Key Points
Exam Focus:
Understand the staged nature of the procedure
Know the common debranching patterns (e.g., ascending aorta to supra-aortic vessels)
Recognize the primary indications and contraindications
Differentiate between early and late complications, with stroke and spinal cord ischemia being paramount concerns.
Clinical Pearls:
The "frozen elephant trunk" technique is a conceptual precursor and often integrated into modern hybrid arch repairs
Careful planning for stent graft landing zones, considering potential migration and interference with arch vessel flow, is critical
Ligation of the left subclavian artery is often performed to facilitate stent graft deployment in the arch and minimize Type II endoleak risk.
Common Mistakes:
Inadequate preoperative imaging leading to poor anatomical assessment
Compromising flow to essential arch branches during stent graft deployment
Failure to adequately treat endoleaks
Insufficient postoperative blood pressure control
Underestimating the risk of stroke and spinal cord ischemia
Lack of long-term surveillance.