A comprehensive meta-analysis with metaregression of available comparative studies to determine whether TEVAR improves morbidity, mortality, and resource-related outcomes compared with open surgery for adults presenting with thoracic aortic disease (degenerative aneurysm, dissection, traumatic rupture, intramural hematoma, and penetrating aortic ulcer) was performed by Cheng et al. (2010). Data from 42 comparative studies with a total of 5888 patients were included in this meta-analysis. Cumulative 30-day all-cause mortality was reduced for TEVAR versus open surgery (odds ratio: 0.44), but cumulative all-cause mortality at 1 year and at 2–3 years did not differ significantly between TEVAR and open surgery groups. At minimum, the existing evidence showed that survival for TEVAR is not worse than for open surgery at midterm. The overall risk of stroke was similar for TEVAR versus open surgery, paraplegia or paraparesis (permanent or temporary), however, were significantly reduced for TEVAR versus open surgery. TEVAR may also reduce length of hospital stay and overall complications including neurologic, cardiac, respiratory, renal, and bleeding complications, without a significant increase in the need for reintervention during mid-term follow-up.

Biancari et al. (2016) determined the efficacy of TEVAR for degenerative DTAA. Eleven studies reporting on 673 patients were selected for the analysis. Technical success was reported in 91.0% of patients, and pooled overall 30-day, 1-year, 2-year, and 3-year survival rates were 96.0%, 80.3%, 77.3%, and 74.0%, respectively. Paraplegia occurred in 3.2% of patients and was permanent in 1.4% of patients. The stroke rate was 2.7%. Early type I endoleak was observed in 7.3%, type II endoleak in 2.0%, and type III in 1.2% of patients. At 3 years, freedom from reintervention was 90.3%. Death secondary to aneurysm rupture and/or fistula was reported in 3.2% of patients.

Jonker et al. (2010) identified 28 articles describing 224 patients with ruptured DTAA (rDTAA) between 1995 and 2009, including 143 patients (63.8%) treated with TEVAR and 81 (36.2%) treated with open repair. Endovascular repair was associated with a significantly lower 30-day mortality rate compared with open surgical repair (19% vs. 33%). The 30-day occurrence rates of myocardial infarction (11.1% vs 3.5%), stroke (10.2% vs 4.1%), and paraplegia (5.5% vs 3.1%) were increased after open repair vs TEVAR, but this failed to reach statistical significance for stroke and paraplegia. However, endovascular repair was associated with a considerable number of aneurysm-related deaths during follow-up, mainly caused by late rupture after TEVAR. The estimated aneurysm-related survival at 3 years after TEVAR was 70.6%.

Gopaldas et al. (2010) evaluated short-term outcomes of TEVAR and open aortic repair using the US Nationwide Inpatient Sample (NIS) data from 2006 to 2007. Only patients with an isolated DTAA were analyzed, patients with aneurysm rupture, aortic dissection, vasculitis, connective tissue disorders, or concomitant aneurysms in other aortic segments were excluded. Nine thousand one-hundred and six patients had undergone conventional OR and 2563 had undergone TEVAR. The patients who had undergone TEVAR were older and had higher comorbidity scores. The unadjusted LOS was shorter for the TEVAR patients (7.7 ± 11 vs 8.8 ± 7.9 days), but the unadjusted mortality was similar (TEVAR 2.3% vs OR 2.3%). TEVAR patients had 60% fewer complications overall (odds ratio, 0.39), and were 4 times more likely to have a routine discharge to home. In addition, Gopaldas et al. (2011) identified from NIS 923 patients who underwent ruptured DTAA repair in 2006–2008 and who had no concomitant aortic disorders. Of these patients, 364 (39.4%) underwent TEVAR and 559 (60.6%) underwent OR. Unadjusted mortality was 23.4% for TEVAR and 28.6% for OR. After risk adjustment, the odds of mortality, complications, and failure to rescue were similar for TEVAR and OR, but patients undergoing TEVAR had a greater chance of routine discharge (odds ratio = 3.3). In smaller hospitals, TEVAR was associated with lower complication rates than OR. Regression analysis revealed that smaller hospital size predicted significantly higher rates of mortality, complications, and failure to rescue in those undergoing OR but not in those undergoing TEVAR. The authors concluded that TEVAR may be an ideal alternative to OR for ruptured DTAA, particularly in small hospitals where expertise in OR may be lacking and immediate transfer to a higher echelon of care may not be feasible.

Further analysis of the NIS data came from Kilic et al. (2014). Adults undergoing DTAA repair between 1998 and 2008 were identified and patients with connective tissue disorders, aortic dissection, or thoracoabdominal aneurysms were excluded. A total of 20,568 DTAA patients (intact, 17,780; ruptured, 2788) underwent repair (open, 15,265; endovascular, 5303). Patients undergoing repair in the more recent era had higher comorbidity burdens than those undergoing repair in the earlier era. Despite of this, annual rates of repair for both intact and ruptured DTAA increased significantly during the study period (intact, 2.2–10.6 per 1 million; ruptured, 0.8–1.3 per 1 million), primarily because of increases in rates of endovascular repair in recent years. Operative mortality decreased from 10.3% to 3.1% for repairs of intact DTAA and from 52.6% to 23.4% for ruptured DTAA.

Goodney et al. (2011) studied 12,573 Medicare patients for the years 1998–2007 who underwent open procedures and 2732 patients who underwent TEVAR for DTAA. By presentation status, 13,998 patients presented for surgery with intact DTAA (11,565 open repair, 2433 TEVAR), whereas 1307 patients underwent surgery for ruptured DTAA (1008 open repair, 299 TEVAR). The lowest perioperative mortality rate occurred in patients undergoing repair of intact DTAA with TEVAR (6.1%), perioperative mortality rate for open repair was slightly higher (7.1%). Among patients presenting with ruptured thoracic aneurysms, perioperative mortality was 28.4% for TEVAR and 45.6% for open repair. Even though patients with intact DTAA selected for TEVAR had lower perioperative mortality, patients selected for open repair reclaimed survival advantage within 5 years (survival: 72% open repair, 62% TEVAR). After 5 years, <30% of patients were alive after repair of their ruptured DTAA regardless of the type of repair (26% open repair, 23% TEVAR). In this study, the survival advantage gained in the perioperative period after endovascular repair of intact DTAA was lost in the follow up period and survival at 5 years was significantly worse for patients selected for TEVAR compared with open repair. Therefore, the widespread application of TEVAR might have resulted in a cohort of patients who previously may not have undergone surgery but now are undergoing TEVAR (selection of “sicker” patients for TEVAR). Alternatively, these differences in survival could be explained by device-related complications occurring within the first 5 years after surgery.

This analysis of the Medicare database was extended and published additionally by Goodney et al. (2013). In this study, in thoracic aortic aneurysm repair a clear inverse relationship between caseload of hospitals and hospital mortality was shown for OR, but not for TEVAR. There was a significant difference in perioperative mortality across volume strata for open surgical repair (13.5% in very low-volume hospitals (annual volume 1–4 cases), 7.3% in very high-volume hospitals (annual volume > 46 cases)). However, there was no difference in perioperative mortality across volume strata for TEVAR (9.0% in very low-volume hospitals (annual volume 0–1 cases), 7.3% in very high-volume hospitals (annual volume > 18 cases)).

The volume-outcome relationship was also reviewed by Patel et al. (2013) in the Medicare Provider Analysis and Review (MEDPAR) data set from 2004 to 2007. Seven-hundred and sixty-three hospitals performing 3554 OR and 3517 TEVAR for intact DTAA were identified. Overall DTAA repair increased from 1375 in 2004 to 1987 in 2007. The proportion of hospitals performing open repair significantly decreased from 95% in 2004 to 57% in 2007, whereas those performing TEVAR increased from 24% to 76%. Overall repair type shifted from open (74% in 2004) to TEVAR (39% open in 2007). Overall mortality during the study interval for open repair was 15% at LV (low volume) hospitals (<8 cases/year) vs 11% at HV (high volume) hospitals (≥8 cases/year), whereas TEVAR mortality was similar, at 3.9% in LV vs 5.5% in HV hospitals. In conclusion, operative mortality for TEVAR was independent of hospital volume and type, whereas mortality after open surgery was lower at HV hospitals, suggesting that TEVAR can be safely performed across a spectrum of hospitals, whereas open surgery should be performed only at HV hospitals.

The Centers for Medicare and Medicaid Services administrative database for the years 2005–2010 was used by Schaffer et al. (2015a). They analyzed post-TEVAR survival in 3751 patients with isolated TAA. Midterm patient survival was 84% at 1 year and 54% at 5 years. This group (Schaffer et al. 2015b) also studied a total of 1767 patients from the Medicare database who underwent open DTAA repair in the period from 1999 to 2010. In this cohort, patients’ survival was 74% at 1 year and 29% at 10 years after surgery. The late incidence of death beyond 180 days paralleled that of an age-, sex-, and race-matched general US population cohort. Independent hospital and surgeon effects, hospital and surgeon volume, and a more recent date of surgery correlated with improved survival.

Not only in the US, but also in England and Wales an increase in descending aortic repairs since the introduction of TEVAR has been observed (von Allmen et al. 2013). In 2005, the overall rate of repairs of DTAA was 0.7 versus 1.9 per 100,000 population in the year 2010. The most marked increase has been in those aged 75+ years. Whilst the rate of open repairs has been fairly steady, the increases were entirely attributable to the increased rate of TEVAR. For DTAA, TEVAR procedures have risen since 2006 from 0.65 to 1.71 and from 0.24 to 0.83 per 100,000 population in men and women, respectively. The authors emphasized that TEVAR is still a practice without a solid evidence base and the survival benefit in consequence of the rising number of procedures remains in doubt. This was demonstrated by another study from von Allmen et al. (2014) where patients aged over 50 years, without a history of aortic dissection, undergoing repair of a thoracic aortic aneurysm between 2006 and 2011 were assessed using mortality-linked individual patient data from Hospital Episode Statistics (England). Overall, 759 patients underwent DTAA repair, mainly for intact aneurysms (618, 81.4%). For intact aneurysms, the operative mortality rate was similar for TEVAR and open repair (6.5 versus 7.6%), but the 5-year survival rate was significantly worse after TEVAR (54.2 versus 65.6%). Aortic-related mortality was similar in the two groups, but cardiopulmonary mortality was higher after TEVAR. TEVAR was associated with more aortic-related reinterventions (23.1 versus 14.3%). There were 141 procedures for ruptured thoracic aneurysm, with TEVAR showing no significant advantage in terms of operative mortality. In conclusion, no clear data could be given to prove the clinical effectiveness of TEVAR compared with open repair for intact DTAA.

The influence of gender on outcomes of TEVAR for nonruptured DTAA examined Arnaoutakis et al. (2014) in a retrospective review of prospectively collected data in the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database from 2005 to 2011. The cohort overall consisted of 649 patients, with 279 women (43%) and 370 men (57%). Women had longer overall operative times and were also more likely to require an iliac artery exposure for device delivery. Unadjusted overall 30-day mortality was 4.4% and was higher in women (6%) than in men (3%). In multivariable analysis female gender did not reach statistical significance for an independent association with 30-day mortality. In contrast, advanced age, emergency surgery, and need for iliac artery exposure were all characteristics independently associated with greater odds of 30-day mortality. The results suggest a need for decreased device delivery size and improvements in endovascular technology.