PB0045 - SEM and 3D reconstruction of ex-vivo arterial thrombi: A pilot study

Sunday, June 25, 2023

18:30 – 19:30 ET

Room: Exhibition

Co-Author(s)

Barbara Baráth, PhD

Post-doc
Department of Genetic Medicine and Development, Faculty of Medicine, University of Geneva, Geneva, Switzerland
Geneva, Geneve, Switzerland

Co-Author(s)

FG

Fréderic Glauser

MD
Division of Angiology and Hemostasis, University Hospitals of Geneva, Geneva, Switzerland
Geneve, Geneve, Switzerland
SN

Stéphan Noble

MD
Division of Cardiology, University Hospitals of Geneva, Geneva, Switzerland
Geneve, Geneve, Switzerland
Pierre Fontana, MD PhD (he/him/his)

Head of Geneva Platelet Group
Division of Angiology and Haemostasis, University Hospitals of Geneva, Switzerland
Geneva, Geneve, Switzerland

Presenting Author(s)

Rita Marchi

PhD
UNIGE
Geneva, Geneve, Switzerland

Co-Author(s)

MN

Marguerite Neerman-Arbez

Professor
Department of Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
Geneva, Geneve, Switzerland
Alessandro Casini, MD

MD
Division of Angiology and Hemostasis, Faculty of Medicine, Geneva University Hospitals, Geneva, Switzerland
Geneva, Geneve, Switzerland

Background: Thromboembolism, including acute limb ischemia (ALI) and myocardial infarction (MI), is the leading cause of death and disability worldwide. On one side, arterial thrombosis can result from atherosclerotic plaque rupture that exposes sub-endothelial cells and procoagulant material, leading to platelet activation and aggregation in high shear rates and stress. On the other side, cardio-embolism can lead to an acute occlusion of the vessel.

Aims: The primary aim of our study was to compare clot composition among ALI thrombi from plaque rupture, embolisms and MI thrombi. We present some preliminary results.

Methods: Ex-vivo thrombi were collected by thrombectomy (ALI n=1; MI n=1) and analysed by Scanning Electron Microscopy (SEM) and SEM 3D reconstruction and compared to whole blood thrombus obtained in vitro from a healthy subject (made with addition of thrombin and calcium) (n=1). The external and internal surfaces of the thrombi were investigated after fixation and dehydration with SEM. SEM/FIB system was used to assess the ultrastructural organization of the clots. Thermo Scientific Amira, Imaris and ImageJ 2.3.0./1.51v software were used for the reconstruction.

Results: In MI thrombi we observed a biconcave shape of RBCs under the surface with a polyhedral shape of RBCs and abundant WBCs in the middle of the thrombi. Heterogenous networks of fibrin on the external and internal surfaces were identified compared to healthy controls. We found larger spaces between cells in the ALI thrombi and denser spaces in the MI thrombi.

Conclusion(s): In our pilot study the thrombi from ALI, MI and controls showed differences in the fibrin network. Future studies will include analysing the nature and number of different cells (WBCs, platelets and microparticles) found in the thrombi, categorising the types of fibrin fibers and the different shapes of RBCs, in order to define how specific cells are involved in the thrombus generation.