Evaluation of Aortic Zone 2 Landing Accuracy During Thoracic Endovascular Aortic Repair Following Carotid-Subclavian Revascularization

The thoracic aorta distal to the left subclavian artery (LSA) is prone to dissection, aneurysmal degeneration and traumatic injury. Therefore, zone 2 landing during thoracic endovascular aortic repair (TEVAR) is commonly required but can prove to be challenging due to its often tortuous and angulated anatomy. Our objective was to determine the landing accuracy of zone-2 targeted endografts following carotid-subclavian revascularization (CSR), which is routinely performed at our institution. Retrospective review of patients that underwent CSR for zone 2 endograft delivery at Vancouver General Hospital between January 1, 2007, and October 1, 2018, was carried out. Patient demographics and comorbidities as well as indication, urgency and imaging modality of treatments were documented. Accuracy of zone 2 delivery was evaluated by two independent reviewers using postoperative computed tomography scans. TEVAR with CSR was performed in 55 patients for treatment of aneurysms (45.5%), dissections (34.5%) or trauma (20%). Mean age was 62.2 ± 19.4 years, with 72.7% males. Urgent cases (<24 hours) occurred in 52.7% of cases. Eight cases (14.5%) required immediate rescue procedures: four (7.3%) proximal cuffs due to type Ia endoleak and four (7.3%) immediate left common carotid artery revascularization with retrograde stent. Thirty cases (54.5%) of LSA stump filling were noted on follow-up imaging. Average proximal endograft landing distance from the left common carotid artery was 12.1 mm. Cases performed using built-in fluoroscopy machine compared with mobile C-arm were associated with higher chance of proximal cuff extensions (odds ratio, 12.3; 95% confidence interval, 1.15-131.11). The need for immediate rescue procedures was not associated with pathology, urgency of surgery or postoperative mortality. Using current endografts and imaging modalities, zone 2-targeted TEVARs have suboptimal technical accuracy with high rates of immediate revision and inadequate seal of the LSA.