[Change of paradigms in the surgical treatment of complex thoracic aortic disease]

One of the main issues in complex thoracic aortic disease, requiring the replacement of the ascending aorta, the entire aortic arch and the descending aorta, is the vast amount of surgery necessary to cure the patient. Though one-stage repair is feasible by a clamshell thoracotomy, the associated surgical trauma and perioperative morbidity limit this approach to younger patients only. Classic surgical repair consist of a two-stage strategy, whereby, in the first step, the ascending aorta and the aortic arch are replaced via a midline sternotomy. In the second step, via a lateral thoracotomy, the descending aorta is replaced. The two stages may sum up to a mortality of 20%; furthermore, the waiting period between the stages is associated with a mortality rate of 10% of its own. Additionally, the two-stage strategy has an inherent limitation, due to the comorbidity and advanced age of the majority of patients. Therefore, the second stage cannot be offered to up to 30% of patients. New developments and improvements in aortic surgery were introduced to overcome these shortcomings and to simplify the surgical repair. The "elephant trunk" principle, introduced by Borst et al. in 1983, was an important step to facilitate surgical repair, but still required the second step. With the introduction of endovascular repair of thoracic aortic disease with stent grafts implanted retrograde via the femoral artery, new therapeutic concepts emerged. In the late 1990s, two Japanese groups reported first trials to stabilize the free-floating "elephant trunk" prosthesis by implantation of nitinol stent grafts into the vascular graft. The applied devices were purely custom-made and nonstandardized. The availability of industrially made and CE-marked stent-graft devices raised the possibility to apply them in open aortic arch surgery. The experience with stent-graft devices implanted antegrade into the descending aorta (Medtronic Talent) was reported first by the Essen and the Vienna group. The experience gained with these devices revealed the limitations of the devices designed for pure retrograde aortic delivery. This required a complete redesign and new construction of the stent graft itself as well as the introducer system. In a preliminary series of 14 patients the required stent-graft properties were presented in detail and resulted in the first industrially manufactured standardized and CE-marked Hybrid stent graft (Essen 1 prosthesis, E-vita Open, Jotec), especially made for antegrade open stent grafting of the descending aorta. This device consists of a stent graft with an integrated Dacron vascular prosthesis, enabling for direct and continuous aortic arch replacement after stent grafting of the descending aorta. From 01/2005 to 03/2006, this hybrid prosthesis was implanted in 16 patients (one aneurysm and 15 aortic dissections). In all cases, the underlying pathology within the thoracic aspect of the aorta could be excluded in a one-stage approach. In case of aortic dissection, thrombosis of the false lumen was detectable by transesophageal echocardiography already at the end of surgery. Though long-term results using this new method are not yet available, the initial promising results postoperatively are encouraging toward true one-stage repair by combining classic aortic surgery with open antegrade stent grafting utilizing the newly designed hybrid prosthesis. While surgical trauma is markedly reduced, this treatment option can be offered to elderly patients as well.