Could the prophylactic replacement of the aortic root reduce the risk of dissection in patient with ascending aorta aneurysm?

OBJECTIVES: Identification of a high genetic risk profile in patients with ascending thoracic aortic aneurysms (TAAs) as surgical indicator to prevent Aortic Stanford type A dissection (TAD). METHODS: Aortic specimens were obtained from patients (31 men and 11 women, whose median age 66.16 ± 5.87 years) undergoing surgical repair of TAA (n=24) and TAD (n=18). Histopathological and immunohistochemical analyses were performed using adequate tissue specimens, appropriate techniques and criteria. Furthermore, genetic risk factors were also investigated. RESULTS: Severe cystic medial degeneration, without substitutive fibrosis, plurifocal medial apoptosis and elevated collagenases concentration were observed in all TAD aortic specimens. Same medial degenerative lesions were observed in those cases of TAAs in which aortic wall was thin and weak at the time of operation. The severity of degeneration was common at aortic root with or without dilatation. Significant associations between single nucleotide polymorphisms (-786T/C endothelial nitric oxide synthase enzyme, D/I angiotensin converting enzyme, -1562C/T metalloproteinase-9 and -735C/T metalloproteinase-2) and dissection risk were detected in TAA patients than controls. CONCLUSIONS: The prophylactic replacement of aortic root might be reasonable in TAA patients with thin and weak aortic root wall at the time of operation and a high genetic risk for rupture or dissection. However, our suggestion is based only on histological and genetic features. Clinical data are required to support them.