[Morphology of dissecting aneurysms of the aorta].

A total of 54 dissecting aneurysms have been examined (47 autopsy and 7 operative specimens) from 43 males and 11 females aged 22 to 76 years. Of these, 24 were of type I, 6 of type II, and 24 of type III (according to DeBekey's classification). The various diseases preceeding the dissection were identified and found to include arterial hypertension in half of the cases. Morphologic changes in the aortal wall (medionecrosis, cystic medionecrosis, fragmentation of elastic fibers) were detected in a number of diseases proceeding the dissection, which confirms that these changes were nonspecific. Structural descriptions of the dissecting aneurysms are presented in relation to the time on their onset.