Clot waveform analysis for perioperative hemostatic monitoring of arthroscopic synovectomy in a pediatric patient with hemophilia A and inhibitor receiving emicizumab prophylaxis

Int J Hematol. 2021 Jun;113(6):930-935. doi: 10.1007/s12185-021-03095-w. Epub 2021 Feb 10.


Emicizumab reduces bleeding in patients with hemophilia A and inhibitors (PwHA-I). Coagulation potential during the perioperative period in emicizumab-treated PwHA-I undergoing surgery remains to be evaluated. We describe a 14-year-old boy with HA-I receiving emicizumab prophylaxis who experienced arthroscopic synovectomy. He was treated with a bolus infusion of recombinant factor VIIa (rFVIIa; 80 μg/kg) immediately before surgery, and treatment continued at the same dose every 3 h on day 1, every 4 h on day 2, and every 6 h on day 3. Treatment with rFVIIa was discontinued on day 4. No perioperative bleeding or thrombotic events were observed. Coagulation potential throughout the perioperative period was retrospectively assessed with an easy-to-use clot waveform analysis (CWA). Measurements from CWA returned to within or near the normal range, suggesting successful hemostatic management. Coagulation potentials assessed by CWA showed a significant correspondence with those from a thrombin generation assay (TGA) that is already in use. CWA and TGA could both provide useful data for assessing coagulation potential in the perioperative hemostatic management of emicizumab-treated PwHA-I.

Keywords: Bispecific antibody; Blood coagulation factor inhibitors; Blood coagulation tests; Hemophilia A; Surgery.

Publication types

  • Case Reports

MeSH terms

  • Adolescent
  • Antibodies, Bispecific / administration & dosage*
  • Antibodies, Monoclonal, Humanized / administration & dosage*
  • Blood Coagulation Factor Inhibitors / blood*
  • Blood Coagulation Tests
  • Factor VIIa / administration & dosage*
  • Hemophilia A* / blood
  • Hemophilia A* / therapy
  • Hemostasis*
  • Humans
  • Male
  • Recombinant Proteins / administration & dosage
  • Synovectomy*


  • Antibodies, Bispecific
  • Antibodies, Monoclonal, Humanized
  • Blood Coagulation Factor Inhibitors
  • Recombinant Proteins
  • emicizumab
  • recombinant FVIIa
  • Factor VIIa