Venous stasis (Wessler)

Purpose and method

Purpose : To quantify thrombogenicity, or anti-thrombic effects of a test article. The assay relies on quantitative scoring of the size, weight and number of thrombi within a determined section of a vein. In addition, fibrinogen, Factor-V, and prothrombin levels can be quantified from serum or plasma.

Method : Briefly, two silk sutures, 1 cm apart, are placed around the vessel to form a loose snare. Thrombus formation is induced with single injection of the human FXIa prior to tightening the two snares. Stasis is maintained for 15 min, after which time the vein section is removed and thrombi are weighed and score.

Study outcome :

  • Demonstrate anti-thrombic activity (efficacy)
  • Demonstrate absence of thrombogenicity
  • Thrombi appearance, score, size and number
Compliance : Non GLP

Species : Rabbits, rats, mice


Charles-E. Laurent

Ph.D., Director of In-Vivo Pharmacology

“Over the past 13 years, I had the greatest opportunity to exploit my passion for science at IPST by contributing to the design, and validation of unique assays which are now routinely run and serve to quantify the efficacy in preclinical drug candidates. My greatest contribution was to see the increase in demand for efficacy services such as the rodent model of pulmonary arterial hypertension (PAH), as well as our intravascular thrombosis and hemostasis models.” Charles completed his doctorate in Pharmacology at the Université de Montreal followed by 4 years of post doctorate studies at the University of Pittsburgh in the Department of Molecular Genetics and Biochemistry. His field of expertise includes cardiovascular pharmacology and molecular biology.