Asymmetric medial degeneration of the intrapericardial aorta in aortic valve disease

Background: A geometrical and functional asymmetry in the normal aortic roo t has been recently demonstrated. Whether the distribution of medial degene ration (MD) within the wall of the dilated ascending aorta in adult patient s reflects such asymmetry, still has to be assessed. Methods: Nineteen pati ents with fibrocalcific aortic valve disease and dilatation of the intraper icardial aorta, without clinical signs and familiar history of primary elas tic connective tissue disorders, underwent surgery. Biopsies (57 specimens) were taken in each patient from three areas of the ascending aortic wall d istal to the three sinuses of Valsalva. NM lesions found at histology in ea ch specimen were classified in three degrees. Comparisons were made between the three sites as to distribution of the three degrees and between one si te and the other two as to incidence of the highest degree. Results: A mild degree of NM was found in 26 specimens (45.6%), moderate in 14 (24.6%), se vere in 17 (29.8%). The distribution of the three degrees of MD changes was significantly different between one of the three studied wall areas and th e other two (P <0.001): a significantly greater incidence of the highest de gree of involvement in the aortic wall distal to the non-coronary sinus tha n in the wall areas corresponding to the coronary sinuses was found (P <0.0 01). Conclusions: MD lesions in dilated intrapericardial aorta are more sev ere in the wall area distal to the non-coronary sinus, likely due to haemod ynamic stress asymmetry. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.