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Results of late-onset type A aortic dissection after previous cardiac surgery: Does prior coronary artery bypass grafting affect survival?

Background
This study aims to evaluate the results of late-onset type A aortic dissection following primary cardiac surgery and to compare the outcomes of patients with or without prior coronary artery bypass grafting.


Methods
Between January 2005 and December 2015, data of 32 patients (16 males, 16 females; mean age 58.1±10.9 years; range, 45 to 73 years) who were diagnosed with acute type A aortic dissection and underwent repair with a history of previous cardiac surgery at our institution were retrospectively analyzed. The patients were divided into two groups as those with a history of prior coronary artery bypass grafting (n=16) and the patients with a previous cardiac surgery without prior coronary artery bypass grafting (n=16).


Results
Dissection of the ascending aorta occurred in 32 patients (late acute in 22 and late chronic in 10) who underwent previous cardiac surgery (aortic valve replacement in 12, mitral valve replacement in two, aortic valve replacement + coronary artery bypass grafting in two, coronary artery bypass grafting in 10, mitral valve replacement + coronary artery bypass grafting in four, and dual valve replacement in two patients). The mean time between the first operation and dissection was 4.0±1.5 years. Dissections were treated with the Bentall procedures (n=8), ascending aorta replacement (n=14), ascending aorta replacement + hemiarch replacement (n=4), ascending aorta + aortic valve replacement (n=4) and Bentall + arch replacement (n=2). In-hospital mortality (30-day mortality) was seen in five patients, and oneyear mortality rate was 21.85% (n=7). The survival rates of the all patients for primary cardiac surgery vs primary cardiac surgery + coronary artery bypass grafting were 81.25% vs 75% at one year, 75% vs 68.75% at three years,75% vs 56.25% at five years, 68.75% vs 56.25% at seven years, and 68.75% vs 56.25% at 10 years, respectively (p=0.71, CI: 95%).


Conclusion
Type-A aortic dissections may develop after cardiac operations with or without coronary artery bypass grafting at any time, and irrespective of associated histologies, they may result in high overall in-hospital mortality. With careful planning by prompt intervention, the outcomes in redo sternotomy operations with or without coronary artery bypass grafting for aortic dissections would be consistent the results of spontaneous aortic dissections.