A research team recently compared the use of thromboelastography (TEG) with conventional coagulation metrics to assess coagulability in patients with slow-flow vascular abnormalities and reported that for these patients, TEG may better reflect bleeding and thrombosis risks with surgery than conventional methods do. Results were published in the journal Pediatric Blood & Cancer.

“Due to the complex hemostatic system of patients with slow-flow vascular malformations, they are more prone to having issues with bleeding and clotting,” explained the researchers in their report, also noting that surgical procedures can enhance bleeding or thrombotic risks in these patients.

In this prospective study, 25 patients who had slow-flow vascular malformations had coagulation profiles measured in conjunction with a minor medical procedure that required sedation. Coagulation properties were assessed prior to and at 15- and 30-minute time points after procedure initiation.

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Coagulation properties were assessed through multiple TEG parameters and by conventional methods. TEG parameters involved measures of the rate of clot formation, clot time, clot stability, and clot strength, while conventional methods included analyses of complete blood count, prothrombin time, activated partial thromboplastin time, D-dimer, fibrinogen, and von Willebrand factor antigen.

Patient median age was 15 years (range, 3-47), and procedures they underwent included laser therapy, sclerotherapy, or both.

TEG parameters showed no significant fluctuations during the periods from baseline to 15 or 30 minutes after the start of the procedure. Patients also reportedly experienced no complications related to bleeding or thrombosis during or for up to 1 week following the procedure.

However, conventional coagulation parameters varied during the interval from baseline to 15 minutes after the start of a procedure; mean fibrinogen shifted from 313.3 to 287.6 mg/dL (P =.001), mean platelet count dropped from 272,000 to 256,000 per mL (P =.006), and mean D-dimer shifted from 1.3 to 1.1 mg/L (P =.02). Mean hemoglobin also dropped from 12.8 to 11.8 g/dL (P =.001). From baseline to 30 minutes after procedure initiation, most conventional parameters did not show significant changes.

“In conclusion, we saw no change in TEG parameters despite changes in the conventional studies, suggesting conventional coagulation differences may not be clinically significant in determining risks of bleeding/thrombotic peri-procedure complications in minor procedures,” the researchers concluded in their report.

The researchers cautioned that these results may not be applicable to more invasive procedures or in cases involving significant localized intravascular coagulopathy.


Mack JM, Pierce CD, Richter GT, et al. Analyzing coagulation dynamics during treatment of vascular malformations with thromboelastography. Pediatr Blood Cancer. Published online November 19, 2020. doi:10.1002/pbc.28824