Intrathoracic aneurysms of the innominate and subclavian arteries

Little is known about the natural history and management of aneurysmal aortic arch branch vessels (AABVs). The objectives of this study were to assess the natural history of aneurysmal AABVs and to examine the outcomes of operative intervention.A retrospective review of the Yale radiologic database from 1999 to 2016 was performed. Only those patients with an aneurysmal AABV and a computed tomography scan were selected for review. Patients' demographics, aneurysm characteristics, management, and follow-up information were collected.There were 105 patients with 147 aneurysmal AABVs; 76 were male (72%), with a mean age of 70 years (range, 17-93 years). We identified 63 innominate, 50 left subclavian, 30 right subclavian, and 4 common carotid artery aneurysms. On computed tomography, 65 (62%) had aortic aneurysms and six (6%) had suffered an aortic dissection. Most were asymptomatic (104 [99%]); one had chest pain and an enlarging swollen mass. Twelve (11%) patients underwent operative repair (OR) for 12 aneurysmal AABVs because of symptoms, growth, or concomitant aortic operations; 93 (89%) were observed in the no operative repair (NOR) group with cross-sectional imaging. The overall mean vessel diameter was 2.08 ± 0.68 cm. The mean diameters in the OR and NOR groups were 3.32 ± 1.24 cm and 1.97 ± 0.46 cm, respectively (P = .002). OR included nine bypasses with resection, two stent grafts, and one resection without reconstruction. Two patients developed postoperative hemorrhage requiring re-exploration, one patient developed stent thrombosis, and one patient required pseudoaneurysm repair 20 years after index operation. Mean follow-up was 52 ± 51 months for the NOR group, with no ruptures or emboli. The growth rate was 0.04 ± 0.10 cm/y. On multivariable regression analysis, a descending aortic aneurysm (P = .041) and a left subclavian artery aneurysm (P = .016) were associated with higher growth rates, whereas height was associated with a lower growth rate (P = .001).Aneurysmal AABVs tend to have a benign natural history with slow growth rates and low rates of complications, including rupture and embolization. We recommend expectant observational management for small, incidentally detected aneurysms.