National trends in admissions, repair, and mortality for thoracic aortic aneurysm and type B dissection in the National Inpatient Sample

Objective: The advent of endovascular repair for both thoracic aortic aneurysm and type B dissection has transformed the management of these disease processes. This study was undertaken to better define, compare, and contrast the national trends in hospital admissions, invasive treatments, and inpatient mortality of patients with thoracic aortic aneurysm and type B dissection in the National Inpatient Sample. Methods: 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 receiving 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. Results: Admissions for thoracic aortic aneurysm outnumbered the admissions for type B dissection (69.8%vs 30.2%; P<.001), and the number of admissions for aneurysm grew more rapidly during this time (132% vs 63%; P<.001). Thoracic endovascular aortic repair (TEVAR) for aneurysm experienced an increase in 2005, concordant with Food and Drug Administration approval of TEVAR for thoracic aortic aneurysm indication, then superseded open repair for thoracic aortic aneurysm from 2006 onward. Despite this, the rate of thoracic aortic aneurysm 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 TEVAR for dissection increased in 2006, superseded open repair in 2010, and continues to account for 50.5% of all dissection repairs.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 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 decreased steadily over time (P <.001). Conclusions: Whereas admissions for thoracic aortic aneurysm disease have increased over time, the rate of aneurysm repair has been stable, although TEVAR has supplanted a proportion of open repairs. In contrast, whereas admissions for type B dissection have experienced a more modest increase, there has been a disproportionate increase in type B dissection repair, largely due to increased use of TEVAR. These results show embracing of endovascular technology for dissection through expansion of indication. Despite the increase in rate of repair for type B dissection, inpatient mortality rate was reduced in both aneurysm and dissection patients, influenced by appropriate selection of patients for intervention.