Abstract 12741: Thoracic Aortic Disease: Does Aortic Size Correspond to Medial Degeneration?
Objectives: Significant controversy exists regarding size thresholds for prophylactic resection of thoracic aortic aneurysms. Medial degeneration is thought to be the pathologic precursor to aortic dissection or rupture. However, the relationship between aortic size and degree of medial degeneration remains unclear.
Methods: Between November 2010 and April 2012, 100 consecutive patients were evaluated within a dedicated Thoracic Aortic Clinic and underwent resection of the thoracic aorta. Preoperative and intraoperative data were prospectively collected and pathologic findings were reviewed. Medial degeneration was graded as minimal, mild, moderate, or severe. Univariate and multivariate analyses were performed to find predictors of significant medial degeneration. Mean age was 62 ± 13 years and 81% were male.
Results: The degree of MD was minimal in 50%, mild in 19%, moderate in 14%, and severe in 16%. Aortitis was found in 5 patients. The degree of MD was mildly correlated with aortic size (R = 0.35, p=0.003). In patients with aortic size < 5.5 cm, moderate or severe MD was found in 19%. Patients with bicuspid aortic valves were less likely to have significant MD (10% vs. 45%, p <0.001). Presence of acute or chronic dissection was not associated with significant MD (p > 0.1). Multivariate analysis identified aortic size (OR [95% CI] - 1.07 [1.02 - 1.12]) per cm increase] and non-bicuspid aortic valve (0.19 [0.06 - 0.62]) as significant predictors of medial degeneration. Age, sex, hypertension, and presence of aortic dissection were not predictive of MD.
Conclusions: Medial degeneration within the thoracic aorta is weakly correlated with aortic size and is present in approximately 20% of patients not meeting criteria for aortic resection (size < 5.5 cm). Bicuspid aortic valve disease is not associated with increased medial degeneration. Identification of novel markers of aortic wall weakness is needed for improved risk stratification in patients with thoracic aortic disease.
- © 2012 by American Heart Association, Inc.