National Thoracic Aneurysm Repair Trends
Open Repair for unruptured descending thoracic aneurysms (UDTAA) averaged 3.3 repairs per million from 2000 to 2002 for people 18 years and older (). In 2003, Open Repair increased to 5.6 repairs per million, correlating with an increase in UDTAA diagnosis and introduction of more advanced 16 slice CT scanners (). TEVAR was approved by the FDA in March 2005. TEVARs for UDTAA reported in 2005 NIS numbered 285, which, when adjusted for annual population estimate, equals 1.3 repairs per million. In 2005, Open Repair volume decreased to 3.7 repairs per million. In 2006, TEVAR increased dramatically to 6.2 repairs per million resulting in total repair rates of 9.9 repairs per million. TEVAR and Open Repair in 2007 were similar to 2006 rates. Similar TEVAR and Open Repair rates correlated with stable diagnosis rates for UDTAA despite a dramatic increase in the number of thoracic CT scans in 2007 (). In 2007, estimated number of TEVARs and Open Repairs for UDTAA was 1,103 and 702 respectively.
Unruptured Descending Thoracic Aneurysm Repair, 2000–2007
Unruptured Thoracic Aneurysm Diagnosis and Thoracic CT Scan Utilization, 2000–2007
As shown in , age and repair type appear to be associated for the overall 2007 cohort. Open Repair was the predominant repair type for patients in the 50–59 age group while TEVAR was the main repair type for patients older than 70 years old. Female patients represented 29.77% of all repair patients. There was no observable gender impact on repair type with 62.67% of female patients receiving TEVAR and 60.93% of male patients receiving TEVAR. In the overall cohort, whites represented 75.74% of all UDTAA repairs in 2007, Blacks represented 10.45%, and Hispanics represented 6.34%. However, minorities were more likely to receive TEVAR than whites with 71.43% of Blacks and 94.12% of Hispanics receiving TEVAR vs. 60.59% for Whites.
Age Group vs. Repair Type for Unruptured Descending Thoracic Aneurysms, 2007 NIS Cohort
Abdominal Endovascular Aortic Repair (EVAR)
For comparison purposes, when abdominal aneurysm endovascular technology (EVAR) was introduced, a similar dramatic switch to endovascular technology was noted, but after a brief rise the total abdominal aortic aneurysm (AAA) repair rate remained the same (). Specifically, in September 1999, the FDA approved the Aneurx abdominal stent graft system (Medtronic, Santa Rosa CA). In 2001 an increase in total AAA repair occurred from approximately 120 to almost 160 repairs per million, which correlated with a dramatic increase in EVAR volume from approximately 10 repairs per million in 2000 to approximately 50 repairs per million in 2001. However, in subsequent years total AAA repair rate remained relatively constant at approximately 140 repairs per million with continued increases in EVAR reaching almost 100 repairs per million in 2007.
Abdominal Aortic Aneurysm Repair, 1995–2007
2006 and 2007 Cohort Analyses: Hospitals Performing both TEVAR and Open Repair
Forty-one hospitals in 2006 and 39 hospitals in 2007 performed both TEVAR and Open Repair. This hospital subgroup represents 35.96% in 2006 and 36.11% in 2007 of hospitals in the NIS performing UDTAA repairs. For both 2006 and 2007 cohorts, mean age of TEVAR patients was older than Open Repair patients. In 2006, mean age was 69.7 years for TEVAR vs. 61.5 years for Open Repair with a similar trend in 2007, 69.8 years and 59.7 years respectively (P < .01). Similar trends were observed in 2006 and 2007 cohorts, with TEVAR patients more likely to have the following comorbidities: chronic kidney disease, chronic obstructive pulmonary disease, diabetes, and be a current or previous smoker ().
Comorbidities from Meta-analysis of 2006 and 2007 NIS cohorts at only those institutions performing both TEVAR and Open Repair.
In 2007, the estimated relative risk (RR) for in-hospital mortality was similar for Open Repair vs. TEVAR (RR = 0.71, P = .70) (). However, in 2006 the RR for mortality with Open Repair vs. TEVAR was considerably elevated (RR = 8.48, P <.01). Analysis of complications showed statistically significant less cardiac and respiratory complications with TEVAR in 2006; this trend continued in 2007. The RR for cardiac complications for Open Repair vs. TEVAR was 5.85 (P = .02) in 2006 and 5.36 (P < .01) in 2007. The RR for prolonged ventilation lasting longer than 96 hours was 6.78 (P =.01) in 2006 with a similar trend in 2007, RR = 4.61 (P=.05). Not surprisingly, increased RR for prolonged ventilation in 2006 and 2007 corresponded with a trend for increased RR of tracheostomy in 2007. In 2006 and 2007 TEVAR patients had a shorter length of stay (LOS) than Open Repair patients (2006: 6 days vs. 9 days, P <.01; 2007: 6.5 days vs. 8.5 days P = .10). Inadequate sample sizes in the 2006 subgroup prevented analysis of peripheral vascular disease, hematomas, tracheostomy and sepsis. Inadequate sample sizes in the 2007 subgroup prevented analysis of sepsis.
Complications from Meta-analysis of 2006 and 2007 NIS cohorts at only those institutions performing both TEVAR and Open Repair.
Analysis of the 2007 cohort revealed that the majority of TEVAR and Open Repair patients were discharged home (83.99% vs. 77.89%). However, TEVAR patients were more likely to be discharged home without home health care than Open Repair patients (67.00%, 95% CI (60.34, 73.65) vs. 43.22%, 95% CI (30.51, 55.93)). Similar number of TEVAR and Open Repair patients were discharged to skilled nursing and intermediate care facilities (13.16% (95% CI (8.93, 17.39) vs. 17.95%, 95% CI (8.46, 27.45)).