Practice patterns for thoracic aneurysms in the stent graft era: health care system implications

Abstract

Background: The US Food and Drug Administration approved the first thoracic aneurysm endograft in 2005. However, because the United States lacks a thoracic aneurysm endovascular repair registry, implications of Food and Drug Administration endograft approval on surgical management of thoracic aneurysms in clinical practice are unknown.

Methods: Retrospective review of thoracic aneurysm repair rates for 2000 to 2007 and analysis of patient characteristics and complications for 2006 and 2007 cohorts uses the National Inpatient Sample. International Classification of Diseases, 9th Revision codes were used to identify unruptured descending thoracic aneurysm cases undergoing either thoracic endovascular aortic repair (39.73) or open repair (38.45).

Results: Thoracic aneurysm open repair averaged 3.3 per million from 2000 to 2002 and increased to 5.6 per million in 2003 with introduction of 16 slice computed tomographic scanners. In 2005 endovascular repair was 1.2 repairs per million, which increased dramatically to 6.1 repairs per million in 2006. In 2007, endovascular repair decreased to 4.8 repairs per million while the open repair rate was 3.1 repairs per million. The 2006 and 2007 open repair cohorts had more favorable baseline characteristics compared with the endovascular cohort. Open repair mortality was significantly greater than endovascular mortality in 2006 (estimated relative risk, 8.48; 95% confidence interval 3.03 to 23.75), but not in 2007 (estimated relative risk, 0.71; 95% confidence interval 0.12 to 4.24). Length of stay was greater for open repair in 2006 and 2007.

Conclusions: Thoracic endovascular aortic repair has been rapidly adopted in the United States resulting in increased treatment of thoracic aortic aneurysms. Despite older age and comorbidities, endovascular repair had better outcomes and shorter hospital stays.

Figure 1. Unruptured Descending Thoracic Aneurysm Repair, 2000–2007

Rates for repair of unruptured descending thoracic aneurysms (UDTAA) with open and thoracic endovascular aortic repair (TEVAR) were adjusted for US Census Bureau annual population estimates.

Figure 2. Unruptured Thoracic Aneurysm Diagnosis and Thoracic CT Scan Utilization, 2000–2007

Trends for unruptured thoracic aneurysm diagnosis and thoracic CT scan utilization were determined by identifying the number of unruptured thoracic aneurysms and of thoracic CT scans coded as the principle diagnosis / procedure and adjusting with annual US Census Bureau population estimates.

Figure 3. Age Group vs. Repair Type for Unruptured Descending Thoracic Aneurysms, 2007 NIS Cohort

Number of unruptured descending thoracic aneurysm repairs by age group and repair type (Open Repair vs. Thoracic Endovascular Aortic Repair (TEVAR)) for the NIS 2007 cohort.

Figure 4. Abdominal Aortic Aneurysm Repair, 1995–2007

Trends for abdominal aortic aneurysm (AAA) repair rates were determined by identifying number of principle procedures coded as Open Repair or Endovascular Aortic Repair (EVAR) and adjusting with annual US Census Bureau population estimates.