Outcomes of thoracic endovascular aortic repair using aortic arch chimney stents in high-risk patients.

BACKGROUND: Aortic arch disease is a challenging clinical problem, especially in high-risk patients, in whom open repair can have morbidity and mortality rates of 30% to 40% and 2% to 20%, respectively. Aortic arch chimney (AAC) stents used during thoracic endovascular aortic repair (TEVAR) are a less invasive treatment strategy than open repair, but the current literature is inconclusive about the role of this technology. The focus of this analysis is on our experience with TEVAR and AAC stents.
METHODS: All TEVAR procedures performed from 2002 to 2015 were reviewed to identify those with AAC stents. Primary end points were technical success and 30-day and 1-year mortality. Secondary end points included complications, reintervention, and endoleak. Technical success was defined as a patient's surviving the index operation with deployment of the AAC stent at the intended treatment zone with no evidence of type I or type III endoleak on initial postoperative imaging. The Kaplan-Meier method was used to estimate survival.
RESULTS: Twenty-seven patients (age, 69 ± 12 years; male, 70%) were identified, and all were described as being at prohibitive risk for open repair by the treating team. Relevant comorbidity rates were as follows: coronary artery disease/myocardial infarction, 59%; oxygen-dependent emphysema, 30%; preoperative creatinine concentration >1.8 mg/dL, 19%; and congestive heart failure, 15%. Presentations included elective (67%; n = 18), symptomatic (26%; n = 7), and ruptured (7%; n = 2). Eleven patients (41%) had prior endovascular or open arch/descending thoracic repair. Indications were degenerative aneurysm (49%), chronic residual type A dissection with aneurysm (15%), type Ia endoleak after TEVAR (11%), postsurgical pseudoaneurysm (11%), penetrating ulcer (7%), and acute type B dissection (7%). Thirty-two brachiocephalic vessels were treated: innominate (n = 7), left common carotid artery (LCCA; n = 24), and left subclavian artery (n = 1). Five patients (19%) had simultaneous innominate-LCCA chimneys. Brachiocephalic chimney stents were planned in 75% (n = 24), with the remainder placed for either LCCA or innominate artery encroachment (n = 8). Overall technical success was 89% (one intraoperative death, two persistent type Ia endoleaks in follow-up). The 30-day mortality was 4% (n = 1; intraoperative death of a patient with a ruptured arch aneurysm), and median length of stay was 6 (interquartile range, 4-9) days. Seven (26%) patients experienced a major complication (stroke, three [all with unplanned brachiocephalic chimney]; respiratory failure, three; and death, one). Nine (33%) patients underwent aorta-related reintervention, and no chimney occlusion events occurred during follow-up (median follow-up, 9 [interquartile range, 1-23] months). The 1-year and 3-year survival is estimated to be 88% ± 6% and 69% ± 9%, respectively.
CONCLUSIONS: TEVAR with AAC can be performed with high technical success and acceptable morbidity and mortality in high-risk patients. Unplanned AAC placement during TEVAR results in an elevated stroke risk, which may be related to the branch vessel coverage necessitating AAC placement. Acceptable midterm survival can be anticipated, but aorta-related reintervention is not uncommon, and diligent follow-up is needed.