MicroCT Can Characterize Clots Retrieved With Mechanical Thrombectomy From Acute Ischemic Stroke Patients-A Preliminary Report.

Daniela Dumitriu Lagrange,Seán Fitzgerald,Seán Fitzgerald,Siri Luthman,Pierre-Alexandre Poletti,Paolo Machi,Karen M Doyle,Karen M Doyle,Alexandra Platon,Karl-Olof Lövblad,Isabel Wanke,Isabel Wanke,Maria Isabel Vargas,Olivier Brina,Jatta Berberat,Jatta Berberat,Michel Muster,Philippe Reymond,Vincent Braunersreuther

doi:10.3389/fneur.2022.824091

Abstract

BackgroundCharacterization of the clot occluding the arteries in acute ischemic stroke received ample attention, in terms of elucidating the relationship between the clot composition, its etiology and its amenability for pharmacological treatment and mechanical thrombectomy approaches. Traditional analytical techniques such as conventional 2D histopathology or electron microscopy sample only small parts of the clot. Visualization and analysis in 3D are necessary to depict and comprehend the overall organization of the clot. The aim of this study is to investigate the potential of microCT for characterizing the clot composition, structure, and organization.MethodsIn a pilot study, we analyzed with microCT clots retrieved from 14 patients with acute ischemic stroke. The following parameters were analyzed: overall clot density, clot segmentation with various density thresholds, clot volume.ResultsOur findings show that human clots are heterogeneous in terms of CT intra-clot density distribution. After fixation in formalin, the clots display a shift toward negative values. On average, we found the mean HU values of red clots retrieved from patients to be −153 HU, with SD = 23.8 HU, for the intermediate clots retrieved from patients −193 HU, SD = 23.7 HU, and for the white clots retrieved from patients −229 HU, SD = 64.8 HU.ConclusionOur study shows that volumetric and density analysis of the clot opens new perspectives for clot characterization and for a better understanding of thrombus structure and composition.

Highlights

The composition of occlusive clots in acute ischemic stroke has received vast attention through two dimensional (2D) histopathology investigations [1–3]
Our results are showing that clots retrieved from patients are more diverse in terms of computed tomography (CT) density, and display a widespread distribution, compared to clot analogs with pre-established compositions (Figure 1)
We observed a systematic decrease in clot density, measured in Hounsfield Units (HU), from fresh state, after rinsing with saline solution, and further after fixation in formalin

Summary

Introduction

The composition of occlusive clots in acute ischemic stroke has received vast attention through two dimensional (2D) histopathology investigations [1–3]. While clot analogs are a valuable tool for studying clinical imaging and optimizing interventional techniques, the clots retrieved from patients remain the most valuable substrate for research on clot behavior [7] Traditional techniques, such as conventional 2D histopathology and electron microscopy, provide a wealth of information on clot composition, etiology and markers associated with resistance to treatment [8, 9]. Characterization of the clot occluding the arteries in acute ischemic stroke received ample attention, in terms of elucidating the relationship between the clot composition, its etiology and its amenability for pharmacological treatment and mechanical thrombectomy approaches. Traditional analytical techniques such as conventional 2D histopathology or electron microscopy sample only small parts of the clot. The aim of this study is to investigate the potential of microCT for characterizing the clot composition, structure, and organization

Objectives

Methods

Results

Conclusion