Hybrid aortic arch repair: Facts and hints beyond the statistical truth

Abstract

Central MessageHybrid repair has effectively broadened the therapeutic armamentarium for aortic arch pathologies in frail patients. Technical refinements and a better definition of indications are needed.See Article page 100. Hybrid repair has effectively broadened the therapeutic armamentarium for aortic arch pathologies in frail patients. Technical refinements and a better definition of indications are needed. See Article page 100. Hybrid arch repair refers to a host of different approaches that combine supra-aortic vessel debranching and endovascular therapy that were developed to address aortic multisegmental pathologies in high-risk patients deemed unsuitable candidates for conventional surgery. The complexity of these approaches depends on the nature and extent of the aortic disease, which is often a surrogate marker for a patient's clinical profile. Several technical issues apply. The search for the optimal proximal landing zone, crucial for proper stent graft placement and sealing, has to conform to variable arch angulations, high blood flow, and the pulsatile movement of this aortic segment, as well as the technology of available prosthetic devices. On the other side, despite the reproducibility of the supra-aortic vessel transposition techniques not being a real issue at first sight, a learning curve effect is easily predictable when working within this anatomically neglected area. Besides the highly variable individual pattern of cerebral, spinal, or coronary vascularization, the prevention of embolization of atherosclerotic debris during surgical manipulation, the vulnerability to infectious complications of interposed prosthetic grafts, and the potential for vessel kinking or compression are all issues that should be carefully addressed to optimize outcomes. Inherent merits and indications are under active investigation and several studies and meta-analyses have tried to compare outcomes with conventional surgical therapy.1Koullias G.J. Wheatley III, G.H. State-of-the-art hybrid procedures for the aortic arch: a meta-analysis.Ann Thorac Surg. 2010; 90: 689-697Abstract Full Text Full Text PDF PubMed Scopus (74) Google Scholar Nevertheless, several biases largely prevent any definitive conclusion: a retrospective cohort design, a relatively small sample size, and limited length of follow-up time are the most common. Above all, the peculiar individual clinical mix of extent of aortic disease and frailty make these studies more case-report series than cohort studies. Hiraoka and colleagues2Hiraoka A. Chikazawa G. Totsugawa T. Tamura K. Ishida A. Sakaguchi et al.Objective analysis of midterm outcomes of conventional and the hybrid aortic arch repair by propensity-score matching.J Thorac Cardiovasc Surg. 2017; 154: 100-106.e1Abstract Full Text Full Text PDF Scopus (26) Google Scholar report on a propensity-score matching analysis. Following are some keys to interpretation. Nearly 15 years ago, an authoritative editorial pointed out the relevance of “statistics for the rest of us” and considerable efforts have been dedicated to educate surgeons.3Wechsler A.S. Statistics for the rest of us.J Thorac Cardiovasc Surg. 2001; 122: 207-208Abstract Full Text Full Text PDF PubMed Scopus (3) Google Scholar Did we take it too seriously? Indeed, Hiraoka and colleagues2Hiraoka A. Chikazawa G. Totsugawa T. Tamura K. Ishida A. Sakaguchi et al.Objective analysis of midterm outcomes of conventional and the hybrid aortic arch repair by propensity-score matching.J Thorac Cardiovasc Surg. 2017; 154: 100-106.e1Abstract Full Text Full Text PDF Scopus (26) Google Scholar endured a meticulous 3-step review process to address “the rigor with which statistical analyses are assessed.” If readers had been able to peep through the keyhole, it would have been evident that even the overzealous reviewers' panel had difficulties in dealing with all of the statistics editor's suggestions. Can oranges and apples really be compared through propensity matching? Were all relevant eyeball clinical evaluations really taken into account? Did this analysis justify the complex craftsmanship needed to perform any individual hybrid repair? Do we really need to compare different strategies in the era of patient-tailored approaches? In the hands of a team with remarkable expertise in open surgery, nearly 16% of patients needed a nonconventional approach. Carefully tailored, but largely perfectible, hybrid approaches demonstrated equivalent midterm outcomes but higher rates of postoperative stroke. Definitely not a short cut but rather an alternative path, hybrid repair certainly needs a better definition of indications. Too simple a message for surgical craftsmen? Objective analysis of midterm outcomes of conventional and hybrid aortic arch repair by propensity-score matchingThe Journal of Thoracic and Cardiovascular SurgeryVol. 154Issue 1PreviewThe aim of this study is to evaluate the objective outcomes of conventional total aortic arch repair (CTAR) and hybrid arch repair by using propensity-score matching to reduce selection bias. Full-Text PDF Open Archive