Patients with a Ruptured Abdominal Aortic Aneurysm Are Better Informed in Hospitals with an “EVAR-preferred” Strategy: An Instrumental Variable Analysis of the Dutch Surgical Aneurysm Audit

Eleonora G Karthaus,W.M De Fijter,J.L Van Wanroij,R.B Van Tongeren,A.P Oomen,M.J Testroote,Y.C Montauban Van Swijndregt,B.L Borger Van Der Burg,A Rijbroek,D.H Burger,E.D Ponfoort,J Nieuwenhuizen,S.K Nagesser,J.L Kolkert,J.E Dierikx,T.J Van Der Steenhoven,G Cazander,A.O Sondakh,L.C Huisman,P.C Smit,M.E Bodegom,R.M Krol,J.M Botman,K Türkcan,O.R Wikkeling,J.R Jansbeken,R.A De Roo,W.I Willaert,D.A Stigter,J.E Sybrandy,C.G Manshanden,D.H Nieuwenhuis,R.R Kruse,J.A De Ridder,E.D Wilschut,W.J Thijsse,R.J Bleker,H.P Van ’T Sant,R.G Van Eps,H.W Palamba,M.G Van Andringa De Kempenaer,W Van De Water,P.F Liqui Lung,Niki Lijftogt,E.S Van Hattum,G.N Stultiëns,A.M Van Well,M.C Loubert,P.P Hedeman Joosten,G.J Glade,J.P Van Brussel,M.E Pierie,W.B Barendregt,R.J Hissink,B.I Oranen,D.A Lamprou,M.J Koelemaij,L.G Van Der Hem,Sonia Amodio,R.P Strating,E Tournoij,M Van Den Berg,N.A Koedam,V Brehm,M.S Lemson,P.T Den Hoed,E.C Mattens,M.G Buimer,A.A Vafi,L.M Van Dortmont,J.T Raymakers,M.K Dinkelman,R Voorhoeve,G.J Van Eijck,R.G Hulsebos,M.G Veldman,G.A Vos,W.L Akkersdijk,B De Vos,P.M Schlejen,R.F Van Den Haak,Erik W Van Zwet,D.M Scharn,B.J Telgenkamp,P.H Castenmiller,R.P Tutein Nolthenius,S.C De Jong,M.L Van Zeeland,Jaap F Hamming,G.F Hajer,F.P Schol,M.F Van Der Jagt,J Diks,A Van Der Elst,A.G Peppelenbosch,T.A Jongbloed-Winkel,B.M Wallis De Vries,P Klinkert,A.M Nevenzel-Putters,W.B Van Gent,S.E Buijk,A.S Bode,T.M Smits,A Khodadade Jahrome,M.G Samyn,C.C Naves,C Van Der Waal,M Dirven,M.J Visser,J.A Van Der Vliet,R.C Van Nieuwenhuizen,Roderik Metz ,B.H Vriens,Martijn Dijkstra ,V.J Noyez,Renske Konings ,Roel Vaes ,M.M Reijnen,Patrick W Vriens ,A Krasznai ,Martijn Hommes ,Çağdaş Ünlü ,Marie Josee Van Rijn ,Thanyalak Tha-In ,Alex Ploeg ,Arjan W.j Hoksbergen ,Jan Wille ,Johannes W Drouven ,G.G Koning,Dennis E J G J Dolmans ,Vincent Jongkind ,Rozemarijn J Van Der Vijver-Coppen ,P.M Van Schaik,Jan J Wever ,Raechel J Toorop ,C.H Arts,J.C De Mol Van Otterloo,R.C Van Doorn,E.G Vermeulen,Maarten Snoeijs ,Vincent P W Scholtes ,M H Booster ,Robert Lind ,Bram Fioole ,B.P Vierhout,Jan M.m Heyligers ,H.H Jiang,Marc R Scheltinga ,Marijke J Molegraaf ,M.J Jacobs,Paul Berger ,Christine Keulen ,M.J Faber,Ron Balm ,H.j.m Verhagen ,Rigo Hoencamp ,W.T Bos- Van Rossum,Jan Van Schaik ,Joris J Blok ,Wilbert M Fritschy ,Anna Prent ,Clark J Zeebregts ,Gert J De Borst ,Edith M Willigendael ,Chris Van Weel ,Christine Vermeulen ,Martin Teraa ,I.F Tielliu,B J M Leenders ,Franceline A Frans ,H.G De Groot,M.M Van Der Eb,Irene Thomassen ,B.h.p Elsman ,Ozan Yazar ,Olaf Schouten ,W M C Mulder ,K.M Huntjens,M.t.c Hoedt ,F Van Hoek,M.R Kapma,A.A De Smet,R.H Geelkerken,Martijn Bruijn ,Pingping Jin ,G J M Akkersdijk ,Roel Janssen ,Luuk Smeets ,J H C Daemen ,Felix J.v Schlösser ,Edward Hollander ,P.J Van Den Akker,Monika Morak ,Pieter B Salemans ,Bart A.n Verhoeven ,Cornelis G Vos ,Abbey Schepers ,Ernst Cancrinus ,J.K Kievit,Jacques Oskam ,J A M Avontuur ,Maarten A Lijkwan ,M Reichart,Maarten Truijers ,R.p.r Groenendijk ,Peter Klemm ,Jan Bosma ,E.F De Haan,M.I Van Engeland,Mare M.a Lensvelt ,P.H Cuypers,George P Akkersdijk ,Jozien Helleman ,R.h.j Kropman ,Maarten Loos ,Bart‐Jeroen Petri ,M De Vries,Kak K Yeung ,Ckh Wong ,Cornelis J Hopmans ,Wouter Hogendoorn ,Geert Willem H Schurink ,Nio D ,Ivo C.j.h Post ,Robert A Pol ,Ariane Coester ,Koen M Van De Luijtgaarden ,Sebastiaan Velthuis ,Ben R Saleem ,Gwan H Ho ,I Dawson,J.H Nederhoed,Werner H Hoffmann ,Michiel A Schreve ,H.J Smeets,Bastiaan Govaert ,Maarten J Van Der Laan ,A.p.m Boll ,Michiel C Warlé ,Rosanne Wouda ,Tryntsje Fokkema ,Hugo T.c Veger ,R Smeets ,M.E Witte,R.j.th.j Welten ,R Meerwaldt,Evert J Waasdorp ,Mart Bender ,C.h.a Wittens ,Theo P Menting ,Eelco J Veen ,Ellen V Rouwet ,Mirza M Idu ,Lee H Bouwman ,Jan D Blankensteijn ,Dink A Legemate ,S.M Van Sterkenburg,A.C Vahl,B.P Keller,Esmee M Van Der Willik ,D Eefting,Dalia Mahmoud ,H.c.j.l Buscher ,J.H Van Laanen,Johanna M Hendriks ,Olivier H.j Koning ,Michiel T Voûte ,Jan-Willem Hinnen ,G.J Lauret,G.C Von Meijenfeldt,V.J Leijdekkers,Anliu Nie ,Jean-Paul Pm De Vries ,J.h.p Lardenoye ,Joost R Van Der Vorst ,C.E Hazenberg,Jan-Willem Elshof ,Koen E Van Der Bogt ,Barend Mees ,Joep A.w Teijink ,P Poyck ,Guus W Van Lammeren ,A.C De Vries,Joost A Van Herwaarden ,Joost A Bekken ,Willem Wisselink ,B.L Reichmann,Alexander Te Slaa ,M.J Speijers,André S Van Petersen ,Jorg L De Bruin ,Olaf J Bakker ,Robert C Minnee ,M.R Van Sambeek,Sander Ten Raa ,Mara Buijs ,C.j.j.m Sikkink ,M.C Willems,Arno M Wiersema ,De Vries ,Gijs M.j.m Welten ,Fabian Linden ,P Brummel,A Vos ,B.L Bendermacher,R.J Beuk,R.H Van De Mortel,Laurens A Van Walraven ,R.A Stokmans,L Van Der Laan

doi:10.1016/j.avsg.2020.06.015

Eleonora G Karthaus, W.M De Fijter + Show 308 more

Open Access

https://doi.org/10.1016/j.avsg.2020.06.015

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Abstract

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. 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. 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. 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.

Highlights

In the elective treatment of abdominal aortic aneurysms, minimal invasive endovascular aneurysm repair (EVAR) has proven to be superior to conventional open surgical repair (OSR) in the short-term/ midterm, with a lower postoperative mortality and morbidity.[1]
An ‘‘EVAR preference strategy’’ in patients with an ruptured abdominal aortic aneurysm (RAAA) could result in lower postoperative mortality
Large observational studies, adjusting for known confounders, suggested a lower postoperative mortality in patients with an RAAA treated with EVAR.7e9 observational studies suffer from indication bias by important prognostic baseline differences between patients and the adjustment of confounders can be incomplete as clinical and social interactions in the diagnostic-treatment pathway are often not measured.[10]

Summary

Introduction

In the elective treatment of abdominal aortic aneurysms, minimal invasive endovascular aneurysm repair (EVAR) has proven to be superior to conventional open surgical repair (OSR) in the short-term/ midterm, with a lower postoperative mortality and morbidity.[1]. 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. 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. 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. Using IV analysis, adjusting for observed and unobserved confounders, RD was 8.9% (95% CI -1.1e18.9%) in favor of EVAR

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