UK EVAR Trial 1: 15-Year Follow-Up Findings
EVAR provides an early survival advantage that is completely lost by 8 years, after which open repair demonstrates superior survival, primarily due to late aneurysm sac ruptures in EVAR patients. 1
Primary Mortality Outcomes
Overall Survival
- Over a mean follow-up of 12.7 years (maximum 15.8 years), there was no significant difference in all-cause mortality between EVAR and open repair (9.3 vs 8.9 deaths per 100 person-years; adjusted HR 1.11,95% CI 0.97-1.27, p=0.14) 1
- The initial operative survival benefit of EVAR completely dissipated over time, with a reversal of the survival advantage occurring after 8 years 1
Time-Dependent Mortality Patterns
- 0-6 months post-randomization: EVAR demonstrated significantly lower mortality (adjusted HR 0.61 for total mortality; HR 0.47 for aneurysm-related mortality, p=0.031) 1
- Beyond 8 years: Open repair showed significantly lower mortality (adjusted HR 1.25 for total mortality, p=0.048; HR 5.82 for aneurysm-related mortality, p=0.0064) 1
Aneurysm-Related Deaths
Late Rupture Risk
- The increased aneurysm-related mortality in the EVAR group after 8 years was primarily attributable to secondary aneurysm sac rupture: 13 deaths (7%) in EVAR versus 2 deaths (1%) in open repair 1
- This finding represents a critical failure mode of EVAR that manifests only with extended follow-up 1
Cancer Mortality
- An unexpected finding was increased cancer mortality in the EVAR group during long-term follow-up, though the mechanism remains unclear 1
Reintervention Rates
- EVAR required significantly more reinterventions throughout the entire follow-up period: 4.1 per 100 person-years in EVAR versus 1.7 per 100 person-years in open repair (p<0.001) 2
- Postoperative complications within 4 years occurred in 41% of EVAR patients versus only 9% of open repair patients (p<0.0001) 3
- Reinterventions in the EVAR group continued throughout the entire follow-up period, not just in the early years 2
Cost-Effectiveness Analysis
- The mean difference in costs over 14 years was £3,798 higher for EVAR (95% CI £2,338 to £5,258) 2
- Economic modeling demonstrated that the cost per quality-adjusted life-year gained exceeds conventional UK thresholds, making EVAR not cost-effective compared to open repair 2
- At 4 years, mean hospital costs were £13,257 for EVAR versus £9,946 for open repair (mean difference £3,311) 3
Quality of Life
- After 12 months, there was negligible difference in health-related quality of life between the two groups 3
- This finding is particularly important as it eliminates quality of life as a justification for choosing EVAR over open repair in fit patients 3
Clinical Implications
Surveillance Requirements
- Lifelong surveillance is mandatory for EVAR patients to detect complications early and trigger timely reintervention 1, 2
- The late rupture deaths highlight failures in surveillance systems or inability to prevent rupture despite surveillance 1
Patient Selection
- These findings apply specifically to patients aged ≥60 years with aneurysms ≥5.5 cm who are anatomically suitable and fit for both procedures 1
- The 2022 ACC/AHA guidelines acknowledge that while EVAR has lower perioperative mortality, this advantage dissipates over time with higher rates of late rupture and aneurysm-related death after 8 years 4
Device Considerations
- An important caveat is that devices used in EVAR trial 1 were implanted between 1999 and 2004; newer devices might have improved durability, though this remains unproven in long-term randomized trials 2