Will hybrid techniques replace open surgery for aortic arch repair?

Abstract

A great controversy remains when comparing open aortic arch repair and hybrid aortic surgery. Many surgeons consider conventional surgeries upon the arch as highly morbid procedures that are associated with high mortality rates. In contrary to that belief, arch surgeries have proven by evidence to be safe and effective, with low morbidity and mortality, thanks to the advances achieved in terms of perfusion and surgical techniques. The main factors that stand in the face of surgical aortic arch repair are related to lack of fitness for such major operation, as most patients carry significant morbidities pre-operatively. In the other hand, many aortic surgeons question the concept behind using endoluminal stent-grafts for exclusion of aortic pathology. Endovascular interventions are rapidly growing with developments achieved in that field outpacing the available data, and the enthusiasm behind the growth in utilization of such techniques is partly driven by industrial efforts. Yet, evidence has declared encouraging results, especially after the high success rates achieved with abdominal aortic disease. Open arch surgery shows lower mortality rates in an era of enhanced cardiothoracic surgical techniques, while it still represents a major operative encounter for highly morbid patients in whom general anesthesia and the burden of the inflammatory response caused by the heart-lung machine are better to be avoided whenever possible. In such patients, the utilization of a hybrid strategy would prevent the patient from exposure to the hazards of the heart lung machine and deep hypothermia. Yet, open surgery remain the only option for some anatomic extents of the disease where endovascular stent grafting will remain helpless in excluding the diseased segment. Great deal of information is lacking, as well as inconsistency of the available data and the lack of an agreed consensus about standardized definitions regarding aortic arch repair and end points, mandate the emergence of expert committees to establish solid guidelines to guide the best practice methods for aortic arch repairs. One of these efforts is established as a multicenter project, namely the ARCH project carried out by the International Aortic Arch Surgery Group (IASSG), to evaluate outcomes of aortic arch surgery among 41 arch surgeons from 10 countries. The project aims at achieving a proper consensus with respect to the outcomes of variable surgical techniques in terms of mortality and morbidity, identify pre-operative risk predictors and formulate risk models, as well as attaining databases for mid and long-term outcomes. Despite that lack of evidence, the results reported by many authors hold promise towards both the conventional arch surgery and the hybrid methods. The superiority of one technique over the other is not the goal to be achieved; it is rather how each technique can complement the other. The durability of open repairs provides better long term outcomes especially when used in young patients. While the minimally invasive nature of endovascular stent-grafting represents salvage for highly morbid patients, unfit for conventional open surgery, in whom, a staged procedure would magnify the risk; on the expenses of higher rates of spinal cord injuries and greater long-term radiation exposure, as well as an undetermined long term freedom from re-intervention. Hybrid strategies are emerging in a rapidly growing manner, the lack of epidemiological data regarding aortic pathologies among the Egyptian population stands in the way of achieving cost benefit results for implementing such financially demanding techniques. The adoption of aortic centers would create a better environment to collect proper data, enhance surgeons’ experience and provide better outcome for the patients.