Background
There are two types of surgical cure for an ascending aorta dilatation. The first one consists in replacing only the dilated ascending aorta. The second one is completed by a hemiarch replacement in order to prevent future arch dilatation and/or dissection but this means more complex surgical techniques and a heavier operative risk. Our primary aim is to assess if the aortic arch presents a significant dilatation following the replacement of the ascending aorta and hereby identify if it is necessary to systematically perform a hemiarch replacement, as is customary in some centers, for example if there is a bicuspid aortic valve.
Methods
This is a monocentric study with a prospective register. 397 patients who underwent an ascending aorta downsizing between 1995 and 2012 were studied. Post-operative thoracic aorta computed tomography (CT) or magnetic resonance imaging (MRI) was performed in 123 patients (of which 61 have a bicuspid aortic valve) at a median follow-up of 5.3 years (0.0 - 17.9 years). When available, pre-operative imaging of the same modality was compared to subsequent imaging.
Results
Survival analysis of the 397 operated patients shows an operative mortality of 3.0% and an overall survival of 75% ± 4% at 12 years, compared to 88% for age and sex-matched Belgian population. Aortic diameters measured at Valsalva’s sinuses, sino-tubular junction and ascending aorta were lower than in pre-operative settings (p<0.001). Conversely, the aortic arch (p=0.018) and the descending aorta (p=0.023) indicated a clinically minor (less than 1mm on average) but statistically significative diameter increase. These results should be interpreted in the light of the natural evolution of thoracic aortic diameters with age (approximately 1mm per decade). The follow-up of 397 operated patients highlights 1 late reoperation for arch dilatation, but the patient had nor a bicuspid aortic valve nor a conjonctive tissue disease. 5 patients presented an aortic arch dissection of which 4 were treated conservatively.
Conclusion
This study supports that it is not reasonable to systematically replace the aortic hemiarch when confronted with a surgical ascending aorta dilatation. Indeed, patients who underwent surgical cure for ascending aorta dilatation will on average develop a clinically negligible dilatation of aortic arch diameters. Moreover, acute aortic arch syndromes do not occur more frequently in patients with bicuspid aortic valves.