A histopathological classification scheme for abdominal aortic aneurysm disease

Laura E Bruijn; Charid G van Stroe Gómez; John A Curci; Jonathan Golledge; Jaap F Hamming; Greg T Jones; Regent Lee; Ljubica Matic; Connie van Rhijn; Patrick W Vriens; Dick Wågsäter; Baohui Xu; Dai Yamanouchi; Jan H Lindeman

doi:10.1016/j.jvssci.2021.09.001

A histopathological classification scheme for abdominal aortic aneurysm disease

JVS Vasc Sci. 2021 Oct 7:2:260-273. doi: 10.1016/j.jvssci.2021.09.001. eCollection 2021.

Authors

Affiliations

¹ Division of Vascular Surgery, Department of Surgery, Leiden University Medical Center (LUMC), Leiden, the Netherlands.
² Section of Surgical Sciences, Department of Vascular Surgery, Vanderbilt University Medical Center, Nashville, Tenn.
³ Queensland Research Centre for Peripheral Vascular Disease, College of Medicine and Dentistry, James Cook University, Townsville, Queensland, Australia.
⁴ Department of Vascular and Endovascular Surgery, The Townsville University Hospital, Townsville, Queensland, Australia.
⁵ Australian Institute of Tropical Health and Medicine, James Cook University, Townsville, Queensland, Australia.
⁶ Department of Surgical Sciences, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand.
⁷ Nuffield Dept. of Surgical Sciences, University of Oxford, Headington, United Kingdom.
⁸ Department of Molecular Medicine and Surgery, Karolinska Institute, Stockholm, Sweden.
⁹ Department of Surgery, Elisabeth-TweeSteden Ziekenhuis, Tilburg, the Netherlands.
¹⁰ Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden.
¹¹ Department of Surgery, Division of Vascular Surgery, Stanford University School of Medicine, Stanford, Calif.
¹² Department of Surgery, School of Medicine and Public Health, University of Wisconsin, Madison, Wisc.

Abstract

Objective: Two consensus histopathological classifications for thoracic aortic aneurysms (TAAs) and inflammatory aortic diseases have been issued to facilitate clinical decision-making and inter-study comparison. However, these consensus classifications do not specifically encompass abdominal aortic aneurysms (AAAs). Given its high prevalence and the existing profound pathophysiologic knowledge gaps, extension of the consensus classification scheme to AAAs would be highly instrumental. The aim of this study was to test the applicability of, and if necessary to adapt, the issued consensus classification schemes for AAAs.

Methods: Seventy-two AAA anterolateral wall samples were collected during elective and emergency open aneurysm repair performed between 2002 and 2013. Histologic analysis (hematoxylin and eosin and Movat Pentachrome) and (semi-quantitative and qualitative) grading were performed in order to map the histological aspects of AAA. Immunohistochemistry was performed for visualization of aspects of the adaptive and innate immune system, and for a more detailed analysis of atherosclerotic lesions in AAA.

Results: Because the existing consensus classification schemes do not adequately capture the aspects of AAA disease, an AAA-specific 11-point histopathological consensus classification was devised. Systematic application of this classification indicated several universal features for AAA (eg, [almost] complete elastolysis), but considerable variation for other aspects (eg, inflammation and atherosclerotic lesions).

Conclusions: This first multiparameter histopathological AAA consensus classification illustrates the sharp histological contrasts between thoracic and abdominal aneurysms. The value of the proposed scoring system for AAA disease is illustrated by its discriminatory capacity to identify samples from patients with a nonclassical (genetic) variant of AAA disease.

Keywords: Abdominal aortic aneurysm; Classification; Histology; Thoracic aortic aneurysm; Vascular remodeling.