Natural History And Management Of Thoracic And Abdominal Aortic Branch Aneurysms

The natural history of thoracic and abdominal aortic branch aneurysms has not been adequately described in the literature. The objectives of this study were to assess the natural history of these aneurysms and examine the outcomes of operative intervention for these aneurysms at Yale-New Haven Hospital. A retrospective review of the Yale radiological database from 01/1999 to 12/2016 was performed. Only patients with an aneurysmal aortic arch branch vessel (AABV), splanchnic artery aneurysm (SAA), or renal artery aneurysm (RAA) and a computed tomography (CT) scan of the chest for AABVs or abdomen for SAAs and RAAs were selected for review. Patients were stratified into either an operative repair (OR) group or non-operative repair (NOR) group. Patient demographics, aneurysm characteristics, management, post-operative complications, and follow-up data were collected. Patients in the NOR group with only one CT scan were considered as lost to follow-up. 105 patients with 147 AABVs, 122 patients with 138 SAAs, and 241 patients with 259 RAAs were identified, with a mean age of 70 years (range: 17-93 years), 66 years (range: 25-94 years), and 69 years (range: 35-100 years), respectively. For AABVs, which had a mean vessel diameter of 2.08 ± 0.68cm, 93 (89%) were followed with cross-sectional imaging and 12 (11%) underwent operative repair. Mean follow-up was 52 ± 51 months for the NOR group with no ruptures or emboli, and the growth rate was calculated as 0.04 ±0.10 cm/year. For SAAs, which had a mean vessel diameter of 1.76 ± 0.83 cm, 101 patients (79%) with 108 SAAs were followed with imaging, whereas 25 (21%) patients with 30 SAA underwent repair. Mean follow-up was 50 ± 42 months for the NOR group without any adverse events related to the SAA, and the mean growth rate was calculated as 0.064 ± 0.18 cm/year. For RAAs, which had a mean diameter of 1.22 ± 0.49 cm, 236 patients (98%) were followed with imaging, while 5 (2%) underwent operative repair. Mean follow-up was 41 ± 35 months for the NOR group without any complications related to the RAA, and the mean growth rate was calculated to be 0.017 ± 0.052 cm/year. There were no ruptures in the NOR group for any aneurysms, but 5 SAAs (including 2 pseudoaneurysms) did present initially as a rupture. AABVs, SAAs, and RAAs 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