Mereuta, Oana M

Background and aim Mechanical thrombectomy (MT) for large vessel occlusion often requires multiple passes to retrieve the entire thrombus load. In this multi-institutional study we sought to examine the composition of thrombus fragments retrieved with each pass during MT. Methods Patients who required multiple passes during thrombectomy were included. Histopathological evaluation of thrombus fragments retrieved from each pass was performed using Martius Scarlet Blue staining and the composition of each thrombus component including RBC, fibrin and platelet was determined using image analysis software. Results 154 patients underwent MT and 868 passes was performed which resulted in 263 thrombus fragments retrieval. The analysis of thrombus components per pass showed higher RBC, lower fibrin and platelet composition in the pass 1 and 2 when compared to pass 3 and passes 4 or more combined (P values <0.05). There were no significant differences between thrombus fragments retrieved in pass 1 and pass 2 in terms of RBC, WBC, fibrin, and platelet composition (P values >0.05). Similarly, when each composition of thrombus fragments retrieved in pass 3 and passes 4 or more combined were compared with each other, no significant difference was noted (P values >0.05). Conclusion Our findings confirm that thrombus fragments retrieved with each pass differed significantly in histological content. Fragments in the first passes were associated with lower fibrin and platelet composition compared to fragments retrieved in passes three and four or higher. Also, thrombus fragments retrieved after failed pass were associated with higher fibrin and platelet components.

Aims Prognostication and treatment selection for cardiac amyloidosis requires accurate amyloid typing. The aim of this study was to investigate the utility of histomorphology for predicting type. Methods and results Autopsy cases with cardiac amyloidosis (1998–2010) were typed by the use of mass spectrometry‐based proteomics. Deposition patterns were correlated with amyloid type. Among 108 decedents (mean age 75 years; 69% men), 107 had a single type, including transthyretin (ATTR) (60 cases), amyloid light chain (AL) (32 λ; 12 κ), amyloid A (AA) (two), and apolipoprotein AIV (AApoAIV) (one). Interstitial deposition was more extensive in AL amyloidosis cases than in ATTR cases [odds ratio (OR) 6.8, P = 0.0004]. Histomorphological patterns of interstitial deposition were mixed in 61% of AL amyloidosis cases and in 61% of ATTR cases, but diffuse pericellular deposits favoured AL amyloidosis (OR 10.7, P = 0.0001), nodular deposits favoured ATTR (OR 3.1, P = 0.0229), and discrete pericellular deposits tended to partially favour ATTR (OR 1.7, P = 0.1970). Arterial and venous deposits each favoured AL amyloidosis (OR ranging from 9.3 to 192.0, P‐value ranging from 0.0022 to <0.0001), and were severe in AL amyloidosis. Endocardial deposits favoured AL amyloidosis (OR 46.3, P < 0.0001) and were also more severe in AL amyloidosis. Conclusions The extent and distribution of cardiac amyloidosis strongly correlate with amyloid type, suggesting fundamental differences in the pathobiology of deposition. The tendency for mixed patterns to occur limits the practicality and accuracy of using histopathology for amyloid typing.

Key Points Leukocyte cell-derived chemotaxin-2–associated amyloidosis (ALect2) is a common cause of systemic amyloidosis involving the liver. Recognition and accurate diagnosis of hepatic ALect2 amyloidosis is essential for accurate management of patients with hepatic amyloidosis.