title: Histopathologic composition of cerebral thrombi of acute stroke patients is correlated with stroke subtype and thrombus attenuation.
abstract: BACKGROUND
  We related composition of cerebral thrombi to stroke subtype and attenuation on non-contrast CT (NCCT) to gain more insight in etiopathogenesis and to validate thrombus attenuation as a new imaging biomarker for acute stroke.
  
  
  METHODS
  We histopathologically investigated 22 thrombi retrieved after mechanical thrombectomy in acute stroke patients. First, thrombi were classified as fresh, lytic or organized. Second, percentages of red blood cells (RBCs), platelets and fibrin and number of red, white (respectively RBCs or platelets outnumbering other components with ≥ 15%) or mixed thrombi were compared between large artery atherosclerosis (LAA), cardioembolism, dissection and unknown subtype. Third, correlation between attenuation and RBCs, platelets and fibrin was calculated using Pearson's correlation coefficients (r).
  
  
  RESULTS
  Thrombi were fresh in 73% (n = 16), lytic in 18% (n = 4) and organized in 9% (n = 2). The stroke cause was LAA in eight (36%), cardioembolism in six (27%), dissection in three (14%), and unknown in five (23%) patients. LAA thrombi showed the highest percentage RBCs (median 50 (range 35-90)), followed by dissection (35 (20-40), p = 0.05), cardioembolism (35 (5-45), p = 0.013) and unknown subtype (25 (2-40), p = 0.006). No differences in platelets (p = 0.16) and fibrin (p = 0.52) between subtypes were found. LAA thrombi were classified as red or mixed (both n = 4), cardioembolisms as mixed (n = 5) or white (n = 1) and dissection as mixed (n = 3). There was a moderate positive correlation between attenuation and RBCs (r = 0.401, p = 0.049), and weak negative correlations with platelets (r = -0.368, p = 0.09) and fibrin (r = -0.073, p = 0.75).
  
  
  CONCLUSIONS
  The majority of cerebral thrombi is fresh. There are no differences in age of thrombi between subtypes. LAA thrombi have highest percentages RBCs, cardioembolism and unknown subtype lowest. No relationship exists between subtype and platelets or fibrin percentages. We found a correlation between the RBC-component and thrombus attenuation, which improves validation of thrombus attenuation on NCCT as an imaging biomarker for stroke management.
authors: Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors: Joris M
authors: JM
authors: Niesten
authors: Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors: Irene C
authors: IC
authors: van der Schaaf
authors: Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors: Lievay
authors: L
authors: van Dam
authors: Department of Pathology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors: Aryan
authors: A
authors: Vink
authors: Department of Radiology, St. Antonius Hospital, Nieuwegein, The Netherlands.
authors: Jan Albert
authors: JA
authors: Vos
authors: Department of Neurology, St. Antonius Hospital, Nieuwegein, The Netherlands.
authors: Wouter J
authors: WJ
authors: Schonewille
authors: Department of Pathology, St. Antonius Hospital, Nieuwegein, The Netherlands.
authors: Peter C
authors: PC
authors: de Bruin
authors: Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors: Willem P T M
authors: WP
authors: Mali
authors: Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors: Birgitta K
authors: BK
authors: Velthuis
mesh_terms: D000368:Aged; D050197:Atherosclerosis / Q000503:physiopathology; D015415:Biomarkers / Q000378:metabolism; D001792:Blood Platelets / Q000166:cytology; D004912:Erythrocytes / Q000166:cytology; D005260:Female; D005337:Fibrin / Q000737:chemistry; D006801:Humans; D020767:Intracranial Thrombosis / Q000150:complications* / Q000000981:diagnostic imaging / Q000601:surgery; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D020521:Stroke / Q000150:complications* / Q000000981:diagnostic imaging; D017131:Thrombectomy; D014057:Tomography, X-Ray Computed
chemical_list: D015415:Biomarkers; D005337:Fibrin