OPERATIVE TREATMENT OF AORTIC DISSECTIONS - EXPERIENCE WITH 125 PATIENTS OVER A 16-YEAR PERIOD

Abstract

An unselected, consecutive group of 125 patients underwent operative repair of acute and chronic aortic dissections with tubular graft interposition over 16 yr. The absence of remote geographical referral biases and the unselected nature of this series provided a patient population that was representative of the disease process (previously assessed only from autopsy series). This enabled high-risk subsets to be defined by retrospective analysis. Patients were classified according to whether the ascending aorta was involved (type A with involvement, type B without), irrespective of the site of intimal tear, and according to age of the dissection. Patients [53) had acute type A (Ac-A), 29 had chronic type A (Ch-A), 20 had acute type B (Ac-B), and 23 had chronic type B (Ch-B) dissections. Of the dissections 14% (17/125) had ruptured. Concomitant aortic valve replacement (AVR) was performed in 11% (6/53) for Ac-A cases and 38% (11/29) of the Ch-A cases. A total of 391 patient-years of follow-up was analyzed; follow-up averaged 4.5 yr and extended to 13.7 yr. Overall operative mortality rate was 34% (18/53) for Ac-A, 14% (4/29) for Ch-A, 45% (9/20) for Ac-B, and 22% (5/23) for Ch-B; during the most recent 5 yr interval these figures were lower: 27, 8, 20 and 20%, respectively, no. = 50. Multiple preoperative variables correlated significantly with both operative death and long-term survival. Operative survivors generally experienced satisfactory functional benefit. Late attrition averaged 8%/year; 61% of all late deaths were related to cardiac or cerebral causes. Overall actuarial survival (.+-. SEM (standard error of the mean)) for the entire cohort was 54 .+-. 5% at 5 yr and 26 .+-. 7% at 10 yr; for the 89 patients surviving operation, these figures were 76 .+-. 5% and 37 .+-. 10%, respectively. No significant differences in long-term survival were evident between the different subgroups. Whether the primary intimal tear was resected or concomitant AVR was performed had no statistically significant bearing on operative mortality, functional result, necessity for late reoperation or late attrition. The long-term natural history of surgically treated patients with aortic dissections, as defined in this study, should facilitate comparison with other treatment modalities. Results of the present analysis support immediate operative intervention for patients with Ac-A dissections and probably for those with Ac-B dissections. Surgical treatment of patients with symptomatic or enlarging Ch-A and Ch-B dissections provides satisfactory rehabilitation and long-term survival. A simplified classification of aortic dissections, based solely on the presence or absence of ascending aortic involvement is recommended. Pathophysiology and expected biologic behavior pivot on this feature, and appropriate clinical strategy can be defined.