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; Niki Lijftogt; Anco Vahl; Esmee M van der Willik; Sonia Amodio; Erik W van Zwet; Jaap F Hamming; Dutch Society for Vascular Surgery, the Steering Committee of the Dutch Surgical Aneurysm Audit and the Dutch Institute for Clinical Auditing

doi:10.1016/j.avsg.2020.06.015

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

Ann Vasc Surg. 2020 Nov:69:332-344. doi: 10.1016/j.avsg.2020.06.015. Epub 2020 Jun 15.

Authors

Eleonora G Karthaus¹, Niki Lijftogt², Anco Vahl³, Esmee M van der Willik⁴, Sonia Amodio⁵, Erik W van Zwet⁵, Jaap F Hamming⁶; Dutch Society for Vascular Surgery, the Steering Committee of the Dutch Surgical Aneurysm Audit and the Dutch Institute for Clinical Auditing

Collaborators

Dutch Society for Vascular Surgery, the Steering Committee of the Dutch Surgical Aneurysm Audit and the Dutch Institute for Clinical Auditing:
P J Van den Akker, G J Akkersdijk, G P Akkersdijk, W L Akkersdijk, M G van Andringa de Kempenaer, C H Arts, J A Avontuur, O J Bakker, R Balm, W B Barendregt, J A Bekken, M H Bender, B L Bendermacher, M van den Berg, P Berger, R J Beuk, J D Blankensteijn, R J Bleker, J J Blok, A S Bode, M E Bodegom, K E van der Bogt, A P Boll, M H Booster, B L Borger van der Burg, G J de Borst, W T Bos-van Rossum, J Bosma, J M Botman, L H Bouwman, V Brehm, M T de Bruijn, J L de Bruin, P Brummel, J P van Brussel, S E Buijk, M A Buijs, M G Buimer, D H Burger, H C Buscher, E Cancrinus, P H Castenmiller, G Cazander, A M Coester, P H Cuypers, J H Daemen, I Dawson, J E Dierikx, M L Dijkstra, J Diks, M K Dinkelman, M Dirven, D E Dolmans, R C van Doorn, L M van Dortmont, J W Drouven, M M van der Eb, D Eefting, G J van Eijck, J W Elshof, B H Elsman, A van der Elst, M I van Engeland, R G van Eps, M J Faber, W M de Fijter, B Fioole, T M Fokkema, F A Frans, W M Fritschy, P H Fung Kon Jin, R H Geelkerken, W B van Gent, G J Glade, B Govaert, R P Groenendijk, H G de Groot, R F van den Haak, E F de Haan, G F Hajer, J F Hamming, E S van Hattum, C E Hazenberg, P P Hedeman Joosten, J N Helleman, L G van der Hem, J M Hendriks, J A van Herwaarden, J M Heyligers, J W Hinnen, R J Hissink, G H Ho, P T den Hoed, M T Hoedt, F van Hoek, R Hoencamp, W H Hoffmann, W Hogendoorn, A W Hoksbergen, E J Hollander, M Hommes, C J Hopmans, L C Huisman, R G Hulsebos, K M Huntjens, M M Idu, M J Jacobs, M F van der Jagt, J R Jansbeken, R J Janssen, H H Jiang, S C de Jong, T A Jongbloed-Winkel, V Jongkind, M R Kapma, B P Keller, A Khodadade Jahrome, J K Kievit, P L Klemm, P Klinkert, N A Koedam, M J Koelemaij, J L Kolkert, G G Koning, O H Koning, R Konings, A G Krasznai, R M Krol, R H Kropman, R R Kruse, L van der Laan, M J van der Laan, J H van Laanen, G W van Lammeren, D A Lamprou, J H Lardenoye, G J Lauret, B J Leenders, D A Legemate, V J Leijdekkers, M S Lemson, M M Lensvelt, M A Lijkwan, R C Lind, F T van der Linden, P F Liqui Lung, M J Loos, M C Loubert, K M van de Luijtgaarden, D E Mahmoud, C G Manshanden, E C Mattens, R Meerwaldt, B M Mees, G C von Meijenfeldt, T P Menting, R Metz, R C Minnee, J C de Mol van Otterloo, M J Molegraaf, Y C Montauban van Swijndregt, M J Morak, R H van de Mortel, W Mulder, S K Nagesser, C C Naves, J H Nederhoed, A M Nevenzel-Putters, A J de Nie, D H Nieuwenhuis, J Nieuwenhuizen, R C van Nieuwenhuizen, D Nio, V J Noyez, A P Oomen, B I Oranen, J Oskam, H W Palamba, A G Peppelenbosch, A S van Petersen, B J Petri, M E Pierie, A J Ploeg, R A Pol, E D Ponfoort, I C Post, P P Poyck, A Prent, S Ten Raa, J T Raymakers, M Reichart, B L Reichmann, M M Reijnen, J A de Ridder, A Rijbroek, M J van Rijn, R A de Roo, E V Rouwet, B R Saleem, P B Salemans, M R van Sambeek, M G Samyn, H P van 't Sant, J van Schaik, P M van Schaik, D M Scharn, M R Scheltinga, A Schepers, P M Schlejen, F J Schlosser, F P Schol, V P Scholtes, O Schouten, M A Schreve, G W Schurink, C J Sikkink, A Te Slaa, H J Smeets, L Smeets, R R Smeets, A A de Smet, P C Smit, T M Smits, M G Snoeijs, A O Sondakh, M J Speijers, T J van der Steenhoven, S M van Sterkenburg, D A Stigter, R A Stokmans, R P Strating, G N Stultiëns, J E Sybrandy, J A Teijink, B J Telgenkamp, M Teraa, M J Testroote, T Tha-In, R M The, W J Thijsse, I Thomassen, I F Tielliu, R B van Tongeren, R J Toorop, E Tournoij, M Truijers, K Türkcan, R P Tutein Nolthenius, Ç Ünlü, R H Vaes, A A Vafi, A C Vahl, E J Veen, H T Veger, M G Veldman, S Velthuis, H J Verhagen, B A Verhoeven, C F Vermeulen, E G Vermeulen, B P Vierhout, R J van der Vijver-Coppen, M J Visser, J A van der Vliet, C J Vlijmen-van Keulen, R Voorhoeve, J R van der Vorst, A W Vos, B de Vos, C G Vos, G A Vos, M T Voute, B H Vriens, P W Vriens, A C de Vries, D K de Vries, J P de Vries, M de Vries, C van der Waal, E J Waasdorp, B M Wallis de Vries, L A van Walraven, J L van Wanroij, M C Warlé, W van de Water, V van Weel, A M van Well, G M Welten, R J Welten, J J Wever, A M Wiersema, O R Wikkeling, W I Willaert, J Wille, M C Willems, E M Willigendael, E D Wilschut, W Wisselink, M E Witte, C H Wittens, C Y Wong, R Wouda, O Yazar, K K Yeung, C J Zeebregts, M L van Zeeland

Affiliations

¹ Department of Surgery, Leiden University Medical Center, Leiden, The Netherlands; Dutch Institute for Clinical Auditing, Leiden, The Netherlands. Electronic address: e.g.karthaus@gmail.com.
² Department of Surgery, Leiden University Medical Center, Leiden, The Netherlands; Dutch Institute for Clinical Auditing, Leiden, The Netherlands.
³ Department of Surgery, OLVG, Amsterdam, The Netherlands; Department of Clinical Epidemiology, OLVG, Amsterdam, The Netherlands.
⁴ Dutch Institute for Clinical Auditing, Leiden, The Netherlands; Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, The Netherlands.
⁵ Department of Medical Statistics and Bioinformatics, Leiden University Medical Center, Leiden, The Netherlands.
⁶ Department of Surgery, Leiden University Medical Center, Leiden, The Netherlands.

PMID: 32554198
DOI: 10.1016/j.avsg.2020.06.015

Abstract

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.

Publication types

Comparative Study
Observational Study

MeSH terms

Aged
Aged, 80 and over
Aortic Aneurysm, Abdominal / diagnostic imaging
Aortic Aneurysm, Abdominal / mortality
Aortic Aneurysm, Abdominal / surgery*
Aortic Rupture / diagnostic imaging
Aortic Rupture / mortality
Aortic Rupture / surgery*
Blood Vessel Prosthesis Implantation* / adverse effects
Blood Vessel Prosthesis Implantation* / mortality
Clinical Decision-Making
Endovascular Procedures* / adverse effects
Endovascular Procedures* / mortality
Female
Hospital Mortality
Humans
Male
Medical Audit
Netherlands
Postoperative Complications / mortality
Prospective Studies
Risk Assessment
Risk Factors
Time Factors
Treatment Outcome