title: Risk of Thrombus Fragmentation during Endovascular Stroke Treatment.
abstract: OBJECTIVE
  Periprocedural thrombus fragmentation is a relevant risk in endovascular stroke treatment. Because factors influencing its occurrence are largely unknown, this study addresses a potential relationship between thrombus histology and clot stability.
  
  
  METHODS
  Eighty-five patients with anterior circulation stroke treated with thrombectomy were included in this retrospective study. The number and location of emboli after retrieving the primary thrombus, the number of maneuvers, and TICI scores were evaluated. H&E and neutrophil elastase staining of retrieved clots was performed, and semiquantitative measurements of thrombus components were correlated with procedural parameters.
  
  
  RESULTS
  An inverse correlation between maneuvers required for thrombus retrieval and the number of distal and intermediate emboli was observed (Spearmanr, -0.23;P= .032). Younger patients were at higher risk for periprocedural thrombus fragmentation (Spearmanr, -0.23;P= .032). Bridging thrombolysis tended to be associated with fewer maneuvers (2 vs 3,P= .054) but more emboli (1 vs 0,P= .067). While no consistent correlation between procedural parameters and red/white blood cells and fibrin-/platelet fractions could be found, higher amounts of neutrophil elastase-positive cells within the thrombus were independently associated with the occurrence of multiple emboli (adjusted OR, 4.6; 95% CI, 1.1-19.7;P= .041) and lower rates of complete recanalization (adjusted OR, 0.3; 95% CI, 0.1-0.9;P= .050).
  
  
  CONCLUSIONS
  Younger age, easy-to-retrieve thrombi, and bridging thrombolysis may be risk factors for periprocedural thrombus fragmentation. Findings from standard histologic stains did not provide insight into thrombectomy-relevant thrombus stability. However, higher neutrophil levels in the thrombus tissue were related to an increased risk of periprocedural thrombus fragmentation. This observation aligns with the proposed thrombolytic capacity of neutrophil elastase and points to its potential clinical relevance in the context of stroke thrombectomy.
authors.affiliation: From the Departments of Neuroradiology (J.K., T.B.-B., C.M., J.F.K., C.Z., T.H.).
authors.forename: J
authors.identifier: http://orcid.org/0000-0002-9177-2289
authors.initials: J
authors.lastname: Kaesmacher
authors.affiliation: From the Departments of Neuroradiology (J.K., T.B.-B., C.M., J.F.K., C.Z., T.H.).
authors.forename: T
authors.identifier: http://orcid.org/0000-0003-0266-8947
authors.initials: T
authors.lastname: Boeckh-Behrens
authors.affiliation: Neurology (S.S., L.S., H.P.), Klinikum rechts der Isar, Technical University of Munich, Munich, Germany.
authors.forename: S
authors.identifier: http://orcid.org/0000-0001-6042-4081
authors.initials: S
authors.lastname: Simon
authors.affiliation: From the Departments of Neuroradiology (J.K., T.B.-B., C.M., J.F.K., C.Z., T.H.).
authors.forename: C
authors.identifier: http://orcid.org/0000-0003-4885-7671
authors.initials: C
authors.lastname: Maegerlein
authors.affiliation: From the Departments of Neuroradiology (J.K., T.B.-B., C.M., J.F.K., C.Z., T.H.).
authors.forename: J F
authors.identifier: http://orcid.org/0000-0002-2803-075X
authors.initials: JF
authors.lastname: Kleine
authors.affiliation: From the Departments of Neuroradiology (J.K., T.B.-B., C.M., J.F.K., C.Z., T.H.).
authors.forename: C
authors.identifier: http://orcid.org/0000-0002-4805-9103
authors.initials: C
authors.lastname: Zimmer
authors.affiliation: Neurology (S.S., L.S., H.P.), Klinikum rechts der Isar, Technical University of Munich, Munich, Germany.
authors.forename: L
authors.identifier: http://orcid.org/0000-0001-7142-4116
authors.initials: L
authors.lastname: Schirmer
authors.affiliation: Neurology (S.S., L.S., H.P.), Klinikum rechts der Isar, Technical University of Munich, Munich, Germany.
authors.forename: H
authors.identifier: http://orcid.org/0000-0003-2189-7681
authors.initials: H
authors.lastname: Poppert
authors.affiliation: From the Departments of Neuroradiology (J.K., T.B.-B., C.M., J.F.K., C.Z., T.H.) Thomas-huber@tum.de.
authors.forename: T
authors.identifier: http://orcid.org/0000-0002-8167-8651
authors.initials: T
authors.lastname: Huber
mesh_terms: D000368:Aged; D004617:Embolism / Q000209:etiology*; D057510:Endovascular Procedures / Q000009:adverse effects*; D005260:Female; D006801:Humans; D020767:Intracranial Thrombosis / Q000601:surgery; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D020521:Stroke / Q000601:surgery*; D017131:Thrombectomy / Q000009:adverse effects*; D016896:Treatment Outcome