Large Artery Atherosclerotic Clots are Larger than Clots of other Stroke Etiologies and have Poorer Recanalization rates

Abstract

Objectives: 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. Materials and Methods: 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. Results: 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= 109 mm 2 , Cardioembolic= 52 mm 2 , Cryptogenic= 47 mm 2 and Other= 52 mm 2 (p= 0.014*). LAA patients also had a significantly poorer rate of successful recanalization (mTICI 2c-3) compared to all From the

Does prior administration of rtPA influence acute ischemic stroke clot composition? Findings from the analysis of clots retrieved with mechanical thrombectomy from the RESTORE registry

“…1b). Median RBCs composition was 45 % for bridging-therapy and 44 % for MTalone clots (H1 = 0.018, P = 0.895); median FIB composition was 30 [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40]% for bridging-therapy and 29 % for MT alone (H1 = 0.552, P = 0.458); median PTL composition was 16 % for bridging-therapy and 17 [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28]% for MT alone (H1 = 0.014, P = 0.905). Further analysis was then performed combining size and histological composition (Fig.…”

Characterization of the ‘White’ Appearing Clots that Cause Acute Ischemic Stroke

“…Two recent studies have shown that cardioembolic and cryptogenic clots have a smaller ECA and higher fibrin and platelets/other content compared to LAA clots which are larger and associated with a RBC-rich composition. 10,14 In our cohort, the majority of 'white' We acknowledge that there are also other components in the platelets/other-rich areas identified by MSB so we performed immunohistochemistry to distinguish between platelets and platelet-related factors such as vWF. 15 The high expression of CD42b and vWF in our 'white' clots highlights their critical role in 'white' clots formation.…”

“…ImageJ software ((https://imagej.nih.gov/ij/) was utilized to measure total extracted clot area (ECA) of each clot using the gross image of the clot as previously described. 9,10 First the scale was set and then the polygon tool was used to draw a region of interest around a fragment of the clot, and the area of that fragment was measured individually. The total extracted clot area for each case is defined as the sum of the clot area from all clot fragments within a case.…”

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

“…However, our findings also show that smaller clots were not associated with better recanalization outcome or lower number of passes, which could be related to clot properties and composition, since it has been demonstrated that small, difficult to remove clots are more platelet rich and contain more highly organised fibrin regions. 19,20 It has been demonstrated that administration of rtPA before mechanical thrombectomy reduces clot size. 21 The present study demonstrates the correlation between clot length on CTA/NCCT and area of extracted clot was slightly stronger for the cohort of patients that directly underwent mechanical thrombectomy compared to the patients pre-treated with rtPA.…”