Histologic differences between in situ and embolized carotid web thrombi: a case report

Qun Gao,Ximeng Yang,Daming Wang,Shen Hu,Jun Lu,Junjie Wang

doi:10.1186/s12883-021-02428-w

Abstract

BackgroundThe significance of carotid webs (CaWs) in ischemic stroke is becoming acknowledged. Histological features of clot composition in situ and secondary cerebrovascular embolized thrombi caused by CaW have not been described concurrently. Understanding clots’ histological composition is essential for understanding the pathophysiology of clot formation in CaW.Case presentationA 50-year-old male patient with acute ischemic stroke, which was believed to be caused by ipsilateral CaW, was admitted to the hospital. Mechanical thrombectomy was used to retrieve thromboemboli from the middle cerebral artery. One month thereafter, the patient underwent carotid endarterectomy, and in situ CaW thrombi were retrieved. Histological analysis by hematoxylin and eosin staining revealed that histopathologic embolized thrombi appeared as typical mixed thrombi, 46.03% fibrin/platelet ratio, 48.12% RBCs, and 5.85% white blood cells. In situ thrombi had a higher fibrin/platelet ratio (68.0%), fewer RBCs (17.2%), and 14.8% white blood cells.ConclusionThe histopathology of large vessel occlusion stroke embolized thrombi by CaW is similar to that of other stroke etiologies. However, the clot composition of embolized thrombi significantly differs from that of in situ thrombi. CaW’s in situ thrombi showed predominantly fibrin, and embolized thrombi had equivalent contents of red blood cells and fibrin/platelets. Histopathological differences between in situ and embolized thrombi suggest new research directions for the etiology of embolization. Further studies are required to confirm these results.

Highlights

The significance of carotid webs (CaWs) in ischemic stroke is becoming acknowledged
This report aimed to assess whether histopathological compositional differences exist between CaW thrombi in situ and embolized ones
Discussion and conclusions we provide a histologic examination of the thrombi obtained from either the CaW in situ during carotid endarterectomy (CEA) or during embolectomy in the patient with ipsilateral CaW

Summary

Introduction

Histological features of clot composition in situ and secondary cerebrovascular embolized thrombi caused by CaW have not been described concurrently. Case presentation: A 50-year-old male patient with acute ischemic stroke, which was believed to be caused by ipsilateral CaW, was admitted to the hospital. The patient underwent carotid endarterectomy, and in situ CaW thrombi were retrieved. A carotid web (CaW) is described as a rare focal intimal variant of fibromuscular dysplasia and implicated in acute ischemic stroke [1]. The patient had a history of diabetes and smoking He underwent no regular physical examination and did not receive any antiplatelet or anticoagulant drugs. CTA of the head and neck showed a membrane-like structure in the posterior wall of the right common carotid artery (Fig. 1a) and complete occlusion of the right middle cerebral artery (MCA). DSA revealed that blood vessels were not reoccluded, and the MCA system achieved eTICI3 reperfusion (Fig. 1d)

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