AORTIC DISSECTION AFTER AORTIC-VALVE REPLACEMENT - INCIDENCE AND CONSEQUENCES FOR STRATEGY

From 1986 to 1994, 10 patients were observed to have developed an acut e aortic dissection at some stage after an aortic valve replacement (A VR). Study of the characteristics of these patients showed that all pa tients had an aortic diameter of 50 mm or more (range 50 to 80 mm, mea n 64 mm), and 70% suffered from systemic hypertension. Subsequently, t he echocardiographic database, containing data from 33,105 studies in 21,484 patients, was searched for cases of AVR in which an accurate ao rtic dimension could be measured. Of 524 patients who had undergone AV R, an accurate aortic diameter was recorded in 419. Thirty-seven patie nts had an aortic size greater than 50 mm. All acute dissections occur red in this group of patients. The incidence of acute dissections amon g patients with significant aortic dilatation following AVR was 27%, w hereas the overall incidence of acute dissection after AVR is 0.6%. Al though there was a preponderance of tilting disc mechanical valves in the dissecting patients, the type of valve implanted does not seem to be of any importance. From these observations, we conclude that implan tation of a valved conduit is indicated even in the presence of mild a nnuloaortic ectasia (aortic size = 50 mm). Patients who have had an AV R and show an enlarging aortic diameter exceeding 50 mm should have an elective reoperation at an early stage, especially when systemic hype rtension is present.