Author + information
- aDivision of Cardiovascular Surgery, University of Pennsylvania, Philadelphia, Pennsylvania
- bNew Mexico Heart Institute, Albuquerque, New Mexico
- cUniversity of New Mexico, Albuquerque, New Mexico
- ↵∗Address for correspondence:
Dr. Joseph E. Bavaria, University of Pennsylvania School of Medicine, Surgery, 6 Silverstein, 3400 Spruce Street, Philadelphia, Pennsylvania 19104.
Surgical management of diseases in the descending thoracic aorta (DTA) has long been one of the most challenging areas of cardiovascular surgery. DTA pathology, including aneurysms, dissections, or dissections with an aneurysmal component, are rarely focal processes, but more frequently represent one aspect of a broader disease involving either the more proximal ascending aorta and aortic arch, the more distal abdominal aorta, or even both. These patients often have a high comorbid burden, including coronary disease, ventricular dysfunction, chronic obstructive pulmonary disease, diabetes, or familial genetic aortopathies. Surgically exposing and operating on the descending aorta can be associated with a high degree of morbidity, with risk of paralysis as well as mortality. It is for these and other reasons that cardiovascular surgeons have long sought less invasive yet equally effective interventions for DTA pathology. The U.S. Food and Drug Administration approval of thoracic endovascular aortic repair (TEVAR) in 2005 represented that goal of an effective yet less morbid DTA intervention (1). TEVAR was rapidly and widely adopted, but there has been an ongoing debate as to whether it can deliver a long- or even mid-term benefit to patients over open surgery, with recent studies suggesting the loss of any benefit of TEVAR as soon as 1 year with open surgery having better mid-term outcomes (2–5).
The paper by Chui et al. (6) in this issue of the Journal does well to further inform the outcomes debate of TEVAR versus open surgical repair. The study evaluates a large cohort of Medicare patients from 1999 to 2010 with a minimum of 5-year follow-up through 2014. The study confirms the systemic rather than focal nature of DTA disease, with nearly 17,000 patients being initially evaluated but 11,141 of those patients excluded mostly due to the concomitant procedures. The final propensity matched cohorts for the analysis were 2,470 TEVAR patients and 1,235 open surgical repair patients with isolated DTA aneurysms. There are a few confounders in the study, with the greatest being little contemporary overlap of the 2 interventions with essentially all open cases being before prior to 2005 and all TEVAR cases after that date (Online Figure 1 in Chui et al. ). The authors recognize this limitation for their comparative effectiveness analysis, and in fairness, this represents actual contemporary clinical practice in this patient population.
Chui et al. (6) use 2 important research techniques that are worth highlighting to best adjust for confounders and to apply adequate research and statistical methodology. First, the authors demonstrate a detailed understanding of the strengths and weakness of administrative data, particularly the various Medicare databases, and how to link these databases in a synergistic fashion to obtain the most long-term follow-up and specific pre-operative details on the patient population. In the absence of a national health care record system, the Medicare databases remain the largest clinical database. However, the field of cardiovascular outcomes researchers should continue to try to link databases such that the critical clinical details captured in one database, such as those maintained by the Society of Thoracic Surgeons, could be combined with long-term outcomes in Medicare or other state and proprietary databases. Second, the statistical methods used by Chui et al. (6), particularly restricted mean survival time, also should be recognized because this analysis in many ways is a simpler analysis with fewer assumptions than other long-term survival analyses, including Cox proportional hazard analysis. Restricted mean survival time should become a greater part of the statistical lexicon alongside Kaplan-Meier, logistical regression, and Cox models as something we as the community of cardiovascular surgical outcomes researchers are equally familiar with and use in the appropriate setting.
Looking forward, there are a few important and outstanding questions regarding the surgical management of the DTA. First, while Chui et al. (6) demonstrate a benefit of TEVAR over open surgery for ≤9 years in Medicare patients, the best option for younger patients remains controversial. The reduced short-term risks of paraplegia and mortality with TEVAR must be balanced against the compounded risk of the need for further interventions, and as Chui et al. (6) demonstrated, subsequent intervention can be at a significantly higher risk. Young patients may go from being reasonable operative candidates who stand the most to gain from a durable open repair as their first intervention to a patient initially treated with TEVAR but then exposed to the increased risk of reintervention. The devices available now for TEVAR have improved since the first approval in 2005, and perhaps this will help extend the durability of TEVAR as well as mitigate some of the risk of reintervention. Last, for open DTA surgery, Chui et al. (6) highlight the important association between high-volume and better outcomes in open surgery. This is particularly important given the declining national volume of open DTA surgery with the increased use of TEVAR. Centralized aortic centers of excellence with the capabilities to do both open and endovascular surgery can offer the potential to better determine which candidates may truly benefit from an open operation and which from TEVAR and the nuances within those options to ideally give patients the lowest risk, longest lasting operation.
↵∗ Editorials published in the Journal of the American College of Cardiology reflect the views of the authors and do not necessarily represent the views of JACC or the American College of Cardiology.
Dr. Bavaria has served as site principal investigator or co-principal investigator for W.L. Gore and Associates, Medtronic, and Cook Medical; and has served as a consultant for W.L. Gore and Associates. Dr. McCarthy has reported that he has no relationships relevant to the contents of this paper to disclose.
- Goodney P.P.,
- Travis L.,
- Lucas F.L.,
- et al.
- Cheng D.,
- Martin J.,
- Shennib H.,
- et al.
- Chiu P.,
- Goldstone A.B.,
- Schaffer J.M.,
- et al.