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Type A aortic dissection: diagnosis and management of malperfusion phenomena.

A cute type A aortic dissection (AAD-A) remains one of the challenges of cardiovascular medicine. The decrease in early mortality resulting from technical inadequacies in the repair of the diseased aorta has enabled dissection-induced obstruction of aortic branches to emerge as a more prominent complication. It is the purpose of this study to point out the underlying mechanisms, and to delineate the diagnosis and treatment of the resulting malperfusion phenomena. Since 1978,100 patients have been operated on for AAD-A at our institution. The incidence of early mortality has decreased from 46% during the first 6 years of our experience, to 19% in the more recent 6-year period, demonstrating the results of a sometimes painful learning process. Figure 1 compares the sources of early mortality in the two time periods. The incidence of fatal intraoperative hemorrhage has decreased from 11% to 6%, but obviously has not been entirely eliminated. Malperfusion phenomena accounted for 11% of the deaths in the earlier period, and 5% in the more recent interval The proportion of other fatal events, including irreversible cardiac failure from pericardial tamponade, multiorgan damage, and infection, has dropped significantly from 25% to 6%. Malperfusion phenomena were diagnosed in 39 instances among 29 of our 100 patients (Fig 2). They affected the myocardium in 6, the central nervous system in 17, and the viscera in 7 patients, while the extremities were affected in 9 cases. Eleven patients ultimately died of these complications, and one individual has a persistent neurological deficit.