Study Reports on National Trends in Treatment of Thoracic Aortic Aneurysm and Type B Dissection
June 5, 2018—A study that sought to define, compare, and contrast the national trends in hospital admissions, invasive treatments, and inpatient mortality of patients with thoracic aortic aneurysm (TAA) and type B dissection in the National Inpatient Sample was published by Grace J. Wang, MD, et al in Journal of Vascular Surgery (JVS; 2018;67:1649–1658). The background of the study is that the advent of endovascular repair for both TAA and type B dissection has transformed the management of these disease processes.
The study showed that admissions for TAA disease have increased over time but the rate of aneurysm repair has been stable with thoracic endovascular aortic repair (TEVAR) supplanting a proportion of open repairs. In contrast, admissions for type B dissection have experienced a more modest increase, but there has been a disproportionate increase in type B dissection repair, largely because of an increased use of TEVAR.
The investigators concluded that the results show that endovascular technology for dissection through expansion of indications has been embraced and that despite an increase in the rate of repair for type B dissection, the inpatient mortality rate was reduced in both aneurysm and dissection patients, influenced by the appropriate selection of patients for intervention.
As summarized in JVS, the cohort was derived from International Classification of Diseases, Ninth Revision diagnosis codes for thoracic aortic dissection and thoracic aortic or thoracoabdominal aortic aneurysm. Patients who had type A dissection or ascending aortic repair during their index admission were excluded using International Classification of Diseases, Ninth Revision procedure codes. A total of 155,187 patients were available for analysis from 2000 to 2012.
The investigators found that admissions for TAA outnumbered the admissions for type B dissection (69.8% vs 30.2%; P < .001), and the number of admissions for an aneurysm grew more rapidly during this time (132% vs 63%; P < .001).
TEVAR for aneurysm experienced an increase in 2005, coinciding with US Food and Drug Administration approval of TEVAR for the TAA indication. From 2006 onward, TEVAR superseded open repair for TAA. Despite this, the rate of TAA repair has remained relatively stable over time.
TEVAR for dissection increased in 2006, superseded open repair in 2010, and continues to account for 50.5% of all dissection repairs. Overall, the number of type B dissection repairs has increased (P < .001) over and above the increase in the number of admissions for type B dissection. Despite the increased trends of utilization of TEVAR for both aneurysm and type B dissection, the overall in-hospital mortality rate among patients admitted for either disease state has steadily decreased over time (P < .001), reported the investigators in JVS.