Dissection of the aorta associated with congenital malformation of the aortic valve
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1Surgery Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892.
Insights
Congenital aortic valve malformations are significantly more common in adults experiencing aortic dissection. These malformations often lead to tears in the ascending aorta, highlighting a critical link for cardiovascular health.
Area of Science:
- Cardiovascular Pathology
- Aortic Diseases
- Congenital Heart Abnormalities
Background:
- Aortic dissection is a serious cardiovascular emergency.
- Congenital aortic valve malformations are known risk factors for various cardiac conditions.
- The specific association between congenital aortic valve malformations and aortic dissection requires further elucidation.
Purpose of the Study:
- To analyze the association between congenital aortic valve malformations and non-iatrogenic aortic dissection.
- To investigate the characteristics of aortic dissection in patients with congenitally malformed aortic valves.
Main Methods:
- Retrospective necropsy study of 186 patients with non-iatrogenic aortic dissection over 30 years.
- Detailed examination of aortic valve morphology (tricuspid, bicuspid, unicuspid).
- Analysis of the location of the intimal tear and associated aortic pathologies.
Main Results:
- Congenital aortic valve malformations were present in 8.6% of patients with aortic dissection, a rate significantly higher than in the general population.
- In patients with malformed valves, the aortic dissection tear consistently originated in the ascending aorta.
- Associated conditions included aortic stenosis (37.5%) and aortic coarctation (12.5%).
- Histological examination revealed severe medial degeneration with loss of elastic fibers in 90% of cases.
Conclusions:
- Congenital aortic valve malformations are a substantial risk factor for aortic dissection in adults.
- The ascending aorta is the primary site of dissection initiation in these patients.
- Medial degeneration of the aorta is a common finding, suggesting a shared underlying pathology.
Abstract:
The association of congenital aortic valve malformation and aortic dissection is analyzed. Over a 30 year period, 186 patients with non-iatrogenic aortic dissection were studied at necropsy. The aortic valve was tricuspid in 170 (91.4%), bicuspid in 14 (7.5%) and unicuspid in 2 (1.1%). Among the 16 patients with aortic dissection and a congenitally malformed valve, the age at death ranged from 17 to 82 years (mean 52) and 13 (81%) were men. The entrance tear of the aortic dissection was located in the ascending aorta in all 16 patients with a malformed valve but in only 68% of those with a tricuspid aortic valve. The aortic valve was stenotic in 6 of the 16 patients with a congenitally malformed valve. Fatal rupture of the false channel occurred after acute ascending aortic dissection in each of the 11 patients (none with healed dissection) who did not have operative therapy for the dissection. Two of the 16 patients with a malformed valve compared with no patient with a tricuspid aortic valve had aortic isthmic coarctation. Histologic sections of aorta from 10 patients disclosed severe degeneration of the elastic fibers of the media in 9 patients. Thus, a congenitally malformed aortic valve appears to be present at least 5 times more frequently in adults with than in those without aortic dissection, and in our patients the entrance tear was always in the ascending aorta, which usually had severe loss of elastic fibers in its media.