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Endovascular Versus Open Repair of Abdominal Aortic Aneurysm in 15-Years’ Follow-Up of the UK Endovascular Aneurysm Repair Trial 1 (EVAR trial 1): A Randomised Controlled Trail
Journal of Vascular Surgery
Abstracts
585
Volume 65, Number 2 AAA overall could make screening less cost effective than previously estimated. Bottom line is some things are improving but despite the falling incidence of rAAA, it is still quite common with 3.2 deaths per 100,000 people annually.
Endovascular Versus Open Repair of Abdominal Aortic Aneurysm in 15-Years’ Follow-Up of the UK Endovascular Aneurysm Repair Trial 1 (EVAR trial 1): A Randomised Controlled Trail Patel R, Sweeting MJ, Powell JT, et al. Lancet on line http://dx.doi.org/ 10.1016/S0140-6736 (16)31135-7. Conclusion: EVAR for repair of abdominal aortic aneurysm (AAA) has an early survival benefit but inferior late survival compared with open repair. Summary: In the U.S. Medicare population, endovascular repair compared with open repair of AAA is associated with an early survival advantage, but this gradually decreases over time with catch-up mortality after 3 years (Schermerhorn ML et al, N Engl J Med 2015;373:328-38). The rate of AAA rupture after AAA repair was significantly higher for those who had EVAR than those who had open repair. An observational study in Queensland, Australia, however, reported no differences in 5 year, 10 year and 15 year survival for open repair (n ¼ 982; median follow-up, 6.5 years) compared to EVAR (n ¼ 358; mean follow-up, 4.0 years) (Khashram M et al, Vascular 2016;24:115-25). The EVAR 1 trial also previously reported aneurysm-related mortality and total mortality at 10 years of follow-up with no difference between endovascular and open AAA repair. There was, however, a hint of late secondary sac rupture after EVAR (Wyss TR et al, Ann Surg 2010;252:805-12). The authors here report 15 year followup of the EVAR 1 trial in terms of aneurysm-related and total mortality, cause of death, and aneurysm-related intervention. EVAR 1 enrolled 1252 patients from 37 centers in the UK between September 1, 1999 and August 31, 2004. Patients were aged 60 years or older, with AAAs of at least 5.5 cm in diameter and suitable for both open or EVAR repair. Eligible patients were randomly assigned 1:1 to receive EVAR (n ¼ 626) or open repair (n ¼ 626). Primary analysis compared total and aneurysm-related deaths until mid-2015 in an intention-to-treat population. Twenty-five patients (four from mortality) were lost to follow up by the end of June 30, 2015. Over a mean of 12.7 6 1.5 years (maximum, 15.8 years) they recorded 9.3 deaths per 100 persons in the EVAR group and 8.9 deaths per 100 persons in the open repair group (adjusted HR, 1.11; 95% CI, 0.97-1.27; P ¼ .14). At 0 to 6 months after randomization, patients in the EVAR group had lower mortality (adjusted HR, 0.61 [95% CI, 0.37-1.02] for total mortality and adjusted HR, 0.47 [95% CI, 0.23-0.93] for aneurysm-related mortality; P ¼ .031). Beyond 8 years of follow-up, open repair had significantly lower mortality (adjusted HR, 1.25; 95% CI, 1.0-1.56; P ¼ .048) and aneurysmrelated mortality (adjusted HR, 5.82; 95% CI, 1.64-20.65; P ¼ .0064). Increased aneurysm-related mortality in the EVAR group after 8 years was mainly attributed to secondary aneurysm sac rupture (13 deaths [7%] in EVAR v 2 deaths [1%] in open repair) with increased cancer mortality also observed in the EVAR group. Comment: Obviously, everyone recognizes the devices available today for repair of AAA differ from those that were used in the EVAR 1 trial. In addition, techniques for placing the grafts have improved since EVAR 1. It is possible patients in the EVAR group had more diligent follow-up from those in the open repair group and aneurysm-related mortality may have been under estimated in the open repair group. However, as the authors point out, this should not affect findings of total mortality.
Despite what may be an increased cancer risk associated with EVAR, because of radiation exposure or other unknown reasons, and an increased aneurysm-related mortality, is unlikely patients are going to change their preference for EVAR over open repair. It is also unlikely younger surgeons less familiar with open repair of AAA will change their preferred operative technique for repairing AAAs based on this data. Continued improvements in devices, placement of devices, and timing and types of follow up, hopefully will also improve the late outcomes of this procedure eventually making the results of EVAR 1 irrelevant.
Outcome of the Swedish Nationwide Abdominal Aortic Aneurysm Screening Program Wanhainen A, Hultgren R, Linne A, et al. Circulation 2016;134:1141-8. Conclusion: Screening 65 year old men for abdominal aortic aneurysm (AAA) is an effective preventative health measure and is highly cost effective in a contemporary practice. Summary: Screening for AAA has been adopted in many countries and now we are beginning to see population based studies evaluating the efficacy and/or cost effectiveness of aneurysm screening programs. Sweden’s AAA screening program targeting 65 year old men was gradually introduced since 2006 and reached nationwide coverage in 2015. In this study the authors evaluate the outcomes of this program. Data on the number of invited and examined men, screening detected AAAs, AAAs operated on, and surgical outcomes were retrieved from all 21 Swedish counties for the years 2006 through 2014. AAA-specific mortality data were retrieved from the Swedish Cause of Death Registry. A linear regression analysis was used to estimate the effect on AAA-specific mortality among all men greater $ 65 years of age for the observed time period. The long term effects were predicted using a validated Markov model. Of 302, 957 men aged 65 years invited, 84% attended the screening study. The prevalence of screening detected AAA was 1.5%. After a mean of 4.5 years, 29% of patients with a screen detected AAA had been operated on. 30-day mortality rate was 0.9% (1.3% after open repair and 0.3% after endovascular repair, P < 0.001). Introduction of screening was associated with a significant reduction in AAA specific mortality (mean 4% per year of screening, P ¼ .020). The numbers needed to screen and the numbers needed to operate on to prevent 1 premature death were 667 and 1.5, respectively. With a total population of 9.5 million, the Swedish national AAA screening program was predicted to annually prevent 90 premature deaths from AAA and to gain 577 quality adjusted life years. The incremental cost effectiveness ration was estimated to be 7770 krona per quality adjusted life year. Comment: The study is another of the growing number of studies evaluating the effectiveness of aneurysm screening programs. It confirms what most have hoped showing screening 65 year old men for AAA can be an effective and cost effective preventative health measure. Findings confirm results from the randomized trials of aneurysm screening and should help influence health care decision making in countries that currently have not adopted aneurysm screening. Of course, all results will be local and will be dependent upon the prevalence of individuals responding to screening invitations, cost of screening in individual countries and outcomes of aneurysm intervention in individual countries. Nevertheless, when people attend screening sessions and treatment of AAA has low morbidity and mortality rates it is quite clear aneurysm screening is both medically effective and cost effective.
Abstracts
585
Volume 65, Number 2 AAA overall could make screening less cost effective than previously estimated. Bottom line is some things are improving but despite the falling incidence of rAAA, it is still quite common with 3.2 deaths per 100,000 people annually.
Endovascular Versus Open Repair of Abdominal Aortic Aneurysm in 15-Years’ Follow-Up of the UK Endovascular Aneurysm Repair Trial 1 (EVAR trial 1): A Randomised Controlled Trail Patel R, Sweeting MJ, Powell JT, et al. Lancet on line http://dx.doi.org/ 10.1016/S0140-6736 (16)31135-7. Conclusion: EVAR for repair of abdominal aortic aneurysm (AAA) has an early survival benefit but inferior late survival compared with open repair. Summary: In the U.S. Medicare population, endovascular repair compared with open repair of AAA is associated with an early survival advantage, but this gradually decreases over time with catch-up mortality after 3 years (Schermerhorn ML et al, N Engl J Med 2015;373:328-38). The rate of AAA rupture after AAA repair was significantly higher for those who had EVAR than those who had open repair. An observational study in Queensland, Australia, however, reported no differences in 5 year, 10 year and 15 year survival for open repair (n ¼ 982; median follow-up, 6.5 years) compared to EVAR (n ¼ 358; mean follow-up, 4.0 years) (Khashram M et al, Vascular 2016;24:115-25). The EVAR 1 trial also previously reported aneurysm-related mortality and total mortality at 10 years of follow-up with no difference between endovascular and open AAA repair. There was, however, a hint of late secondary sac rupture after EVAR (Wyss TR et al, Ann Surg 2010;252:805-12). The authors here report 15 year followup of the EVAR 1 trial in terms of aneurysm-related and total mortality, cause of death, and aneurysm-related intervention. EVAR 1 enrolled 1252 patients from 37 centers in the UK between September 1, 1999 and August 31, 2004. Patients were aged 60 years or older, with AAAs of at least 5.5 cm in diameter and suitable for both open or EVAR repair. Eligible patients were randomly assigned 1:1 to receive EVAR (n ¼ 626) or open repair (n ¼ 626). Primary analysis compared total and aneurysm-related deaths until mid-2015 in an intention-to-treat population. Twenty-five patients (four from mortality) were lost to follow up by the end of June 30, 2015. Over a mean of 12.7 6 1.5 years (maximum, 15.8 years) they recorded 9.3 deaths per 100 persons in the EVAR group and 8.9 deaths per 100 persons in the open repair group (adjusted HR, 1.11; 95% CI, 0.97-1.27; P ¼ .14). At 0 to 6 months after randomization, patients in the EVAR group had lower mortality (adjusted HR, 0.61 [95% CI, 0.37-1.02] for total mortality and adjusted HR, 0.47 [95% CI, 0.23-0.93] for aneurysm-related mortality; P ¼ .031). Beyond 8 years of follow-up, open repair had significantly lower mortality (adjusted HR, 1.25; 95% CI, 1.0-1.56; P ¼ .048) and aneurysmrelated mortality (adjusted HR, 5.82; 95% CI, 1.64-20.65; P ¼ .0064). Increased aneurysm-related mortality in the EVAR group after 8 years was mainly attributed to secondary aneurysm sac rupture (13 deaths [7%] in EVAR v 2 deaths [1%] in open repair) with increased cancer mortality also observed in the EVAR group. Comment: Obviously, everyone recognizes the devices available today for repair of AAA differ from those that were used in the EVAR 1 trial. In addition, techniques for placing the grafts have improved since EVAR 1. It is possible patients in the EVAR group had more diligent follow-up from those in the open repair group and aneurysm-related mortality may have been under estimated in the open repair group. However, as the authors point out, this should not affect findings of total mortality.
Despite what may be an increased cancer risk associated with EVAR, because of radiation exposure or other unknown reasons, and an increased aneurysm-related mortality, is unlikely patients are going to change their preference for EVAR over open repair. It is also unlikely younger surgeons less familiar with open repair of AAA will change their preferred operative technique for repairing AAAs based on this data. Continued improvements in devices, placement of devices, and timing and types of follow up, hopefully will also improve the late outcomes of this procedure eventually making the results of EVAR 1 irrelevant.
Outcome of the Swedish Nationwide Abdominal Aortic Aneurysm Screening Program Wanhainen A, Hultgren R, Linne A, et al. Circulation 2016;134:1141-8. Conclusion: Screening 65 year old men for abdominal aortic aneurysm (AAA) is an effective preventative health measure and is highly cost effective in a contemporary practice. Summary: Screening for AAA has been adopted in many countries and now we are beginning to see population based studies evaluating the efficacy and/or cost effectiveness of aneurysm screening programs. Sweden’s AAA screening program targeting 65 year old men was gradually introduced since 2006 and reached nationwide coverage in 2015. In this study the authors evaluate the outcomes of this program. Data on the number of invited and examined men, screening detected AAAs, AAAs operated on, and surgical outcomes were retrieved from all 21 Swedish counties for the years 2006 through 2014. AAA-specific mortality data were retrieved from the Swedish Cause of Death Registry. A linear regression analysis was used to estimate the effect on AAA-specific mortality among all men greater $ 65 years of age for the observed time period. The long term effects were predicted using a validated Markov model. Of 302, 957 men aged 65 years invited, 84% attended the screening study. The prevalence of screening detected AAA was 1.5%. After a mean of 4.5 years, 29% of patients with a screen detected AAA had been operated on. 30-day mortality rate was 0.9% (1.3% after open repair and 0.3% after endovascular repair, P < 0.001). Introduction of screening was associated with a significant reduction in AAA specific mortality (mean 4% per year of screening, P ¼ .020). The numbers needed to screen and the numbers needed to operate on to prevent 1 premature death were 667 and 1.5, respectively. With a total population of 9.5 million, the Swedish national AAA screening program was predicted to annually prevent 90 premature deaths from AAA and to gain 577 quality adjusted life years. The incremental cost effectiveness ration was estimated to be 7770 krona per quality adjusted life year. Comment: The study is another of the growing number of studies evaluating the effectiveness of aneurysm screening programs. It confirms what most have hoped showing screening 65 year old men for AAA can be an effective and cost effective preventative health measure. Findings confirm results from the randomized trials of aneurysm screening and should help influence health care decision making in countries that currently have not adopted aneurysm screening. Of course, all results will be local and will be dependent upon the prevalence of individuals responding to screening invitations, cost of screening in individual countries and outcomes of aneurysm intervention in individual countries. Nevertheless, when people attend screening sessions and treatment of AAA has low morbidity and mortality rates it is quite clear aneurysm screening is both medically effective and cost effective.