| 1. |
- Mereuta, O. M., et al.
(författare)
-
Characterization of the 'White' Appearing Clots that Cause Acute Ischemic Stroke
- 2021
-
Ingår i: Journal of Stroke and Cerebrovascular Diseases. - : Elsevier BV. - 1052-3057. ; 30:12
-
Tidskriftsartikel (refereegranskat)abstract
- Objectives: Most clots retrieved from patients with acute ischemic stroke are 'red' in color. 'White' clots represent a less common entity and their histological composition is less known. Our aim was to investigate the composition, imaging and procedural characteristics of 'white' clots retrieved by mechanical thrombectomy. Materials and methods: Seventy five 'white' thrombi were selected by visual inspection from a cohort of 760 clots collected as part of the RESTORE registry. Clots were evaluated histopathologically. Results: Quantification of Martius Scarlett Blue stain identified platelets/other as the major component in 'white' clots' (mean of 55% of clot overall composition) followed by fibrin (31%), red blood cells (6%) and white blood cells (3%). 'White' clots contained significantly more platelets/other (p<0.001*) and collagen/calcification (p<0.001*) and less red blood cells (p<0.001*) and white blood cells (p=0.018*) than 'red' clots. The mean platelet and von Willebrand Factor expression was 43% and 24%, respectively. Adipocytes were found in four cases. 'White' clots were significantly smaller (p=0.016*), less hyperdense (p=0.005*) on computed tomography angiography/non-contrast CT and were associated with a smaller extracted clot area (p<0.001*) than 'red' clots. They primarily caused the occlusion of middle cerebral artery, were less likely to be removed by aspiration and more likely to require rescue-therapy for retrieval. Conclusions: 'White' clots represented 14% of our cohort and were platelet, von Willebrand Factor and collagen/calcification-rich. 'White' clots were smaller, less hyperdense, were associated with significantly more distal occlusions and were less successfully removed by aspiration alone than 'red' clots.
|
|
| 2. |
- Rossi, R., et al.
(författare)
-
Correlation between acute ischaemic stroke clot length before mechanical thrombectomy and extracted clot area: Impact of thrombus size on number of passes for clot removal and final recanalization
- 2021
-
Ingår i: European Stroke Journal. - : SAGE Publications. - 2396-9873 .- 2396-9881. ; 6:3, s. 254-261
-
Tidskriftsartikel (refereegranskat)abstract
- Introduction: We assessed the correlation between thrombus size before and after mechanical thrombectomy, measured as length by Computed Tomography Angiography/Non-Contrast Computed Tomography (CTA/NCCT) and Extracted Clot Area, ECA, respectively. We also assessed the influence of thrombus size on the number of passes required for clot removal and final recanalization outcome. Materials and methods: Acute ischaemic stroke (AIS) thrombi retrieved by mechanical thrombectomy from 500 patients and data of clot length by CTA/NCCT were collected from three hospitals in Europe. ECA was obtained by measuring the area of the extracted clot. Non-parametric tests were used for data analysis. Results: A strong positive correlation was found between clot length on CTA/NCCT and ECA (rho = 0.619,N = 500, P < 0.0001*). Vessel size influences clot length on CTA/NCCT (H2 = 98.6, P < 0.0001*) and ECA (H2 = 105.6,P < 0.0001*), but the significant correlation between CTA/NCCT length and ECA was evident in all vessels. Poorer revascularisation outcome was associated with more passes (H5 = 73.1, P < 0.0001*). More passes were required to remove longer clots (CTA/NCCT; H4 = 31.4, P < 0.0001*; ECA; H4 = 50.2, P < 0.0001*). There was no significant main association between recanalization outcome and length on CTA/NCCT or ECA, but medium sized clots (ECA 20-40 mm(2)) were associated with least passes and highest revascularisation outcome (N = 500, X-2 = 16.2, P < 0.0001*). Conclusion: Clot length on CTA/NCCT strongly correlates with ECA. Occlusion location influences clot size. More passes are associated with poorer revascularisation outcome and bigger clots. The relationship between size and revascularisation outcome is more complex. Clots of medium ECA take less passes to remove and are associated with better recanalization outcome than both smaller and larger clots.
|
|
| 3. |
- Rossi, R., et al.
(författare)
-
The administration of rtPA before mechanical thrombectomy in acute ischemic stroke patients is associated with a significant reduction of the retrieved clot area but it does not influence revascularization outcome
- 2021
-
Ingår i: Journal of Thrombosis and Thrombolysis. - : Springer Science and Business Media LLC. - 0929-5305 .- 1573-742X. ; 51:2, s. 545-551
-
Tidskriftsartikel (refereegranskat)abstract
- Both intravenous thrombolysis (IVT) and mechanical thrombectomy (MT) are evidence-based treatments for acute ischemic stroke (AIS) in selected cases. Recanalization may occur following IVT without the necessity of further interventions or requiring a subsequent MT procedure. IVT prior to MT (bridging-therapy) may be associated with benefits or hazards. We studied the retrieved clot area and degree of recanalization in patients undergoing MT or bridging-therapy for whom it was possible to collect thrombus material. We collected mechanically extracted thrombi from 550 AIS patients from four International stroke centers. Patients were grouped according to the administration (or not) of IVT before thrombectomy and the mechanical thrombectomy approach used. We assessed the number of passes for clot removal and the mTICI (modified Treatment In Cerebral Ischemia) score to define revascularization outcome. Gross photos of each clot were taken and the clot area was measured with ImageJ software. The non-parametric Kruskal-Wallis test was used for statistical analysis. 255 patients (46.4%) were treated with bridging-therapy while 295 (53.6%) underwent MT alone. By analysing retrieved clot area, we found that clots from patients treated with bridging-therapy were significantly smaller compared to those from patients that underwent MT alone (H-1 = 10.155 p = 0.001*). There was no difference between bridging-therapy and MT alone in terms of number of passes or final mTICI score. Bridging-therapy was associated with significantly smaller retrieved clot area compared to MT alone but it did not influence revascularization outcome.
|
|
| 4. |
- Fitzgerald, Seán, et al.
(författare)
-
Large Artery Atherosclerotic Clots are Larger than Clots of other Stroke Etiologies and have Poorer Recanalization rates.
- 2021
-
Ingår i: Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association. - : Elsevier BV. - 1532-8511. ; 30:1
-
Tidskriftsartikel (refereegranskat)abstract
- There is a paucity of knowledge in the literature relating to the extent of clot burden and stroke etiology. In this study, we measured the Extracted Clot Area (ECA) retrieved during endovascular treatment (EVT) and investigated relationships with suspected etiology, administration of intravenous thrombolysis and recanalization.As part of the multi-institutional RESTORE registry, the ECA retrieved during mechanical thrombectomy was quantified using ImageJ. The effect of stroke etiology (Large-artery atherosclerosis (LAA), Cardioembolism, Cryptogenic and other) and recombinant tissue plasminogen activator (rtPA) on ECA and recanalization outcome (mTICI) was assessed. Successful recanalization was described as mTICI 2c-3.A total of 550 patients who underwent EVT with any clot retrieved were included in the study. The ECA was significantly larger in the LAA group compared to all other etiologies. The average ECA size of each etiology was; LAA=109mm2, Cardioembolic=52mm2, Cryptogenic=47mm2 and Other=52mm2 (p=0.014*). LAA patients also had a significantly poorer rate of successful recanalization (mTICI 2c-3) compared to all other etiologies (p=0.003*). The administration of tPA was associated with a smaller ECA in both LAA (p=0.007*) and cardioembolic (p=0.035*) groups.The ECA of LAA clots was double the size of all other etiologies and this is associated with a lower rate of successful recanalization in LAA stroke subtype. rtPA administration prior to thrombectomy was associated with reduced ECA in LAA and CE clots.
|
|
| 5. |
- Fitzgerald, Seán, et al.
(författare)
-
Per-pass analysis of acute ischemic stroke clots: impact of stroke etiology on extracted clot area and histological composition.
- 2021
-
Ingår i: Journal of neurointerventional surgery. - : BMJ. - 1759-8486 .- 1759-8478. ; 13, s. 1111-1116
-
Tidskriftsartikel (refereegranskat)abstract
- Initial studies investigating correlations between stroke etiology and clot composition are conflicting and do not account for clot size as determined by area. Radiological studies have shown that cardioembolic strokes are associated with shorter clot lengths and lower clot burden than non-cardioembolic clots.To report the relationship between stroke etiology, extracted clot area, and histological composition at each procedural pass.As part of the multi-institutional RESTORE Registry, the Martius Scarlett Blue stained histological composition and extracted clot area of 612 per-pass clots retrieved from 441 patients during mechanical thrombectomy procedures were quantified. Correlations with clinical and procedural details were investigated.Clot composition varied significantly with procedural passes; clots retrieved in earlier passes had higher red blood cell content (H4=11.644, p=0.020) and larger extracted clot area (H4=10.730, p=0.030). Later passes were associated with significantly higher fibrin (H4=12.935, p=0.012) and platelets/other (H4=15.977, p=0.003) content and smaller extracted clot area. Large artery atherosclerotic (LAA) clots were significantly larger in the extracted clot area and more red blood cell-rich than other etiologies in passes 1-3. Cardioembolic and cryptogenic clots had similar histological composition and extracted clot area across all procedural passes.LAA clots are larger and associated with a large red blood cell-rich extracted clot area, suggesting soft thrombus material. Cardioembolic clots are smaller in the extracted clot area, consistent in composition and area across passes, and have higher fibrin and platelets/other content than LAA clots, making them stiffer clots. The per-pass histological composition and extracted clot area of cryptogenic clots are similar to those of cardioembolic clots, suggesting similar formation mechanisms.
|
|
