Electron Microscopic Evaluations of Clot Morphology During Thrombelastography??

Abstract

In this study, we characterized clot morphology with a scanning electron microscope (SEM) at time points corresponding to the commonly used thrombelastography (TEG) variables, illustrating the correlation of the physical clot formation with TEG(R) tracings. The first channel of the TEG analyzer was used to obtain the tracings of clot formation, while the sub-samples for the SEM were obtained from the second TEG channel. Different types of samples were examined, including whole blood, abciximab-treated whole blood, platelet-rich plasma (PRP), and abciximab-treated PRP. The SEM images were obtained at reaction time, different amplitudes (5-30 mm), maximum amplitude (MA), and at amplitude 60 min after MA. In the whole blood, coarse fibrin and activated platelets were observed at reaction time and fibrin strands progressively became more solid and intertwined at amplitude 10 mm and thereafter. Red blood cells were surrounded with fibrin strands at amplitude 30 mm and were tightly packed by fibrin strands at MA. In abciximab-treated whole blood, red blood cell shape was maintained at MA. The process of fibrin formation and platelet activation was also examined in PRP. Abciximab did not block platelet shape change, although the blockage of fibrin binding to platelets was shown on the TEG analyzer. In summary, we have shown structural changes of the forming clot in relation to TEG variables.

Platelet Reactivity in Patients and Recurrent Events Post-Stenting

“…The change in mean platelet aggregation between pre-and postprocedure for the event group was 8% versus 17% for the group without events (p Ͻ 0.001). The near absence of events in patients with Ͻ50% posttreatment aggregation induced by 20 M ADP may also suggests a therapeutic target for P2Y 12 inhibitors. More importantly, ϳ50% of the events occurred in patients with 25th to 75th percentile posttreatment platelet reactivity to ADP.…”

Increased Risk in Patients With High Platelet Aggregation Receiving Chronic Clopidogrel Therapy Undergoing Percutaneous Coronary Intervention

“…Thrombelastograph Hemostasis Analyzer With PlateletMapping. The Food and Drug Administration-approved Thrombelastograph Hemostasis Analyzer With PlateletMapping assay (Haemoscope Corp., Niles, Illinois) relies on the measurement of thrombin-induced clot strength to enable a quantitative analysis of platelet function (15,16). The assay uses heparin as an anticoagulant to eliminate thrombin activity in the sample.…”

Impact of Sonoclot hemostasis analysis after cardiopulmonary bypass on postoperative hemorrhage in cardiac surgery

“…ShoreLesserson et al [12] reported that the intraoperative guidance of hemostatic transfusion with a Thrombelastograph (TEG; Haemoscope, Niles, IL, USA) could reduce bleeding after surgery. One useful TEG variable is the maximum amplitude, which refl ects the interaction of fi brin with platelets [13]. Therefore, reduced platelet-fi brin interaction seems to be a critical indicator of platelet abnormality after CPB.…”