Date of Award

January 2011

Document Type

Open Access Thesis

Degree Name

Medical Doctor (MD)



First Advisor

John A. Elefteriades

Second Advisor

John Geibel

Subject Area(s)



This study investigated the relationship between congenital bovine arch (BA) variant and thoracic aortic aneurysm (TAA), thoracic aortic expansion rate, bicuspid aortic valve (BAV), and aortic complications. We hypothesized that BA would be significantly associated with the presence and progression of thoracic aortic disease.

To determine prevalence of BA, we retrospectively reviewed thoracic CT and/or MRI scans of 616 patients with thoracic aortic disease and 844 patients without thoracic aortic disease (all from Yale-New Haven Hospital). In patients with thoracic aortic disease, we assessed accuracy of official radiology reports in citing BA, and reviewed all available hospital records to determine disease location, thoracic aortic growth rate, presence of bicuspid aortic valve (BAV), and prevalence of thoracic aortic dissection and rupture in patients with and without BA.

BA was observed in 26.1% of patients with thoracic aortic disease and 16.4% of patients without thoracic aortic disease (P<0.001). Radiology reports cited BA in only 16.1% of patients with aortic disease and concomitant BA. There was no association between BA and location of aortic disease, prevalence of dissection (P=0.39), or presence of BAV (P=0.68). Rate of aortic expansion was 0.29 cm/year in the BA group and 0.09 cm/year in the non-BA group (P=0.003). Mean age at initial aortic repair was 56.2 years in BA patients and 61.4 years in non-BA patients (P=0.0004).

Our findings suggest that BA is indeed associated with both the development and progression of thoracic aortic disease, and support the following conclusions: 1) BA is significantly more common in patients with thoracic aortic disease than in the general population. 2) Radiologists often overlook BA. 3) BA is not significantly associated with BAV, aortic dissection, or disease at any particular location within the thoracic aorta. 4) BA is associated with elevated TAA growth rate and earlier repair.