TY - JOUR
T1 - Patients with a Ruptured Abdominal Aortic Aneurysm Are Better Informed in Hospitals with an "EVAR-preferred" Strategy
T2 - An Instrumental Variable Analysis of the Dutch Surgical Aneurysm Audit
AU - Karthaus, Eleonora G
AU - Lijftogt, Niki
AU - Vahl, Anco
AU - van der Willik, Esmee M
AU - Amodio, Sonia
AU - van Zwet, Erik W
AU - Hamming, Jaap F
AU - Dutch Society for Vascular Surgery
AU - Steering Committee of the Dutch Surgical Aneurysm Audit
AU - Dutch Institute for Clinical Auditing
AU - Teijink, Joep
N1 - Copyright © 2020 Elsevier Inc. All rights reserved.
PY - 2020/11
Y1 - 2020/11
N2 - BACKGROUND: While several observational studies suggested a lower postoperative mortality after minimal invasive endovascular aneurysm repair (EVAR) in patients with a ruptured abdominal aortic aneurysm (RAAA) compared to conventional open surgical repair (OSR), landmark randomized controlled trials have not been able to prove the superiority of EVAR over OSR. Randomized controlled trials contain a selected, homogeneous population, influencing external validity. Observational studies are biased and adjustment of confounders can be incomplete. Instrumental variable (IV) analysis (pseudorandomization) may help to answer the question if patients with an RAAA have lower postoperative mortality when undergoing EVAR compared to OSR.METHODS: This is an observational study including all patients with an RAAA, registered in the Dutch Surgical Aneurysm Audit between 2013 and 2017. The risk difference (RD) in postoperative mortality (30 days/in-hospital) between patients undergoing EVAR and OSR was estimated, in which adjustment for confounding was performed in 3 ways: linear model adjusted for observed confounders, propensity score model (multivariable logistic regression analysis), and IV analysis (two-stage least square regression), adjusting for observed and unobserved confounders, with the variation in percentage of EVAR per hospital as the IV instrument.RESULTS: 2419 patients with an RAAA (1489 OSR and 930 EVAR) were included. Unadjusted postoperative mortality was 34.9% after OSR and 22.6% after EVAR (RD 12.3%, 95% CI 8.5-16%). The RD adjusted for observed confounders using linear regression analysis and propensity score analysis was, respectively, 12.3% (95% CI 9.6-16.7%) and 13.2% (95%CI 9.3-17.1%) in favor of EVAR. Using IV analysis, adjusting for observed and unobserved confounders, RD was 8.9% (95% CI -1.1-18.9%) in favor of EVAR.CONCLUSIONS: Adjusting for observed confounders, patients with an RAAA undergoing EVAR had a significant better survival than OSR in a consecutive large cohort. Adjustment for unobserved confounders resulted in a clinical relevant RD. An "EVAR preference strategy" in patients with an RAAA could result in lower postoperative mortality.
AB - BACKGROUND: While several observational studies suggested a lower postoperative mortality after minimal invasive endovascular aneurysm repair (EVAR) in patients with a ruptured abdominal aortic aneurysm (RAAA) compared to conventional open surgical repair (OSR), landmark randomized controlled trials have not been able to prove the superiority of EVAR over OSR. Randomized controlled trials contain a selected, homogeneous population, influencing external validity. Observational studies are biased and adjustment of confounders can be incomplete. Instrumental variable (IV) analysis (pseudorandomization) may help to answer the question if patients with an RAAA have lower postoperative mortality when undergoing EVAR compared to OSR.METHODS: This is an observational study including all patients with an RAAA, registered in the Dutch Surgical Aneurysm Audit between 2013 and 2017. The risk difference (RD) in postoperative mortality (30 days/in-hospital) between patients undergoing EVAR and OSR was estimated, in which adjustment for confounding was performed in 3 ways: linear model adjusted for observed confounders, propensity score model (multivariable logistic regression analysis), and IV analysis (two-stage least square regression), adjusting for observed and unobserved confounders, with the variation in percentage of EVAR per hospital as the IV instrument.RESULTS: 2419 patients with an RAAA (1489 OSR and 930 EVAR) were included. Unadjusted postoperative mortality was 34.9% after OSR and 22.6% after EVAR (RD 12.3%, 95% CI 8.5-16%). The RD adjusted for observed confounders using linear regression analysis and propensity score analysis was, respectively, 12.3% (95% CI 9.6-16.7%) and 13.2% (95%CI 9.3-17.1%) in favor of EVAR. Using IV analysis, adjusting for observed and unobserved confounders, RD was 8.9% (95% CI -1.1-18.9%) in favor of EVAR.CONCLUSIONS: Adjusting for observed confounders, patients with an RAAA undergoing EVAR had a significant better survival than OSR in a consecutive large cohort. Adjustment for unobserved confounders resulted in a clinical relevant RD. An "EVAR preference strategy" in patients with an RAAA could result in lower postoperative mortality.
KW - Aged
KW - Aged, 80 and over
KW - Aortic Aneurysm, Abdominal/diagnostic imaging
KW - Aortic Rupture/diagnostic imaging
KW - Blood Vessel Prosthesis Implantation/adverse effects
KW - Clinical Decision-Making
KW - Endovascular Procedures/adverse effects
KW - Female
KW - Hospital Mortality
KW - Humans
KW - Male
KW - Medical Audit
KW - Netherlands
KW - Postoperative Complications/mortality
KW - Prospective Studies
KW - Risk Assessment
KW - Risk Factors
KW - Time Factors
KW - Treatment Outcome
KW - MORTALITY
KW - OPEN SURGERY
KW - EDITORS CHOICE
KW - TRIAL
KW - ENDOVASCULAR REPAIR
KW - OUTCOMES
U2 - 10.1016/j.avsg.2020.06.015
DO - 10.1016/j.avsg.2020.06.015
M3 - Article
C2 - 32554198
SN - 0890-5096
VL - 69
SP - 332
EP - 344
JO - Annals of Vascular Surgery
JF - Annals of Vascular Surgery
ER -