Owing to the age-related alteration of physiological reserves, age is recognized as an independent predictor of mortality in patients with acute type A aortic dissection, and any complication during the early postoperative period may compromise the survival of elderly patients [2, 4, 14]. The International Registry of Aortic Dissection (IRAD) has shown that patients aged 70 years or older accounted for 31.6% of patients presenting with type A aortic dissection, and as long as life expectancy increases, this number is bound to increase further . Therefore, much more attention should be paid to elderly patients with type A aortic dissection, including clinical characteristics, therapeutic methods, early and late survival. We reviewed the early and late results for eleven elderly patients with acute type A aortic dissection in this study and reported our experience.
There are still many controversies which have been discussed for many years [8, 10, 15].
First, can elderly patients with acute type A aortic dissection benefit more from surgical repair than medicine alone? Many physicians believe that the risk of a surgical repair is too high in older patients to justify such aggressive approach [9, 10]. However, our results clearly show that acceptable results can be obtained with emergency repair in patients 70 years and older; the overall in-hospital mortality in this study is 9.1%, which is comparable to previous reports of surgery on younger patients (5% to 27.4%) [3, 15, 16]. As demonstrated by IRAD, 70% patients die within 1 week without intervention and 40% die with medical treatment alone . Therefore, advanced age should not be considered an absolute contraindication for surgery of acute type A dissection.
Second, is a conservative surgical strategy more justified in the elderly? We hold the opinion that the object of the operation is not to replace the entire area of involved aorta, but to improve supra-arch vessels perfusion, prevent rupture, and recover the aortic valve normal function. Extended aortic arch resection is usually advocated for youger patients, but not for elderly patients: on one aspect, the tissues of elderly patients are more fragile than those of younger patients; on the other aspect, avoiding the hypothermic circulatory arrest (HCA) and only replacing ascending aorta can indeed decrease the morbidity of neurological and respiratory dysfunction. Kawahito and coworkers  reported in their study that the morbidity of renal insufficiency and respiratory dysfuncion were 22% and 25%, respectively, which were much lower than our 45.5% and 54.5%, respectively. However, they reported most elderly patients died of rupture of the residual false lumen in the aortic arch after ascending aorta replacement. In our study, there were no early or late postoperative secondary aortic ruptures. Recently, Chen et al.[11, 19] reported their excellent results with using single- or triple branched stent grafts to extensively repair acute type A aortic dissections with less HCA time.
Thirdly, what kind of cerebral protection strategy is more suitable for elderly patients? Kruger and coworkers  reported that HCA alone and antegrade cerebral perfusion (ACP) led to similar result for circulatory arrest time of less than 30 minutes, and for longer arrest time, outcomes with unilateral and bilateral antegrade cerebral perfusion were equivalent. In the elderly patients, atherosclerosis is more common than youger patients. So, avoiding direct cannulation of supra-arch vessels for cerebral perfusion may decrease the incidence of neurological events. In our early stage, we also used bilateral ACP through right axillary artery and left common carotid artery, but now we think that unilateral ACP by right axillary artery combined with HCP may be a good choice for elderly patients.
This study is limited by its retrospective design. This study also represents a single center approach to a relatively small number of patients. As such, unrecognized confounding factors and selection bias may have also affected our outcomes.