title: In vitro thrombogenesis resulting from decreased shear rate and blood coagulability.
abstract: In vitro antithrombogenic testing with mock circulation is a useful type of pre-evaluation in ex vivo testing of mechanical assist devices. For effective in vitro testing, we have been developing a clear quantitative thrombogenesis model based on shear stress and blood coagulability. Bovine blood was used as the test medium. The activating clotting time (ACT) was adjusted with trisodium citrate and calcium chloride from 200 to 1,000 seconds. The blood was then applied to a rheometer and subjected to shear at 50 to 2,880 s-1. Blood coagulation time and degree of thrombogenesis were measured by the torque sensor of the rheometer. Prothrombin time (PT) and activated partial thromboplastin time (APTT) of the test blood were also measured after the application of shear. Blood coagulation time increased, and the degree of thrombogenesis decreased, with increases in shear rate to between 50 and 2,880 s-1. for test bloods with ACTs of 200 to 250 seconds. An ACT of 200 to 250 seconds is thus appropriate for in vitro antithrombogenic testing under a shear rate of 2,880 s-1. APTT was prolonged, whereas PT did not change, with increasing shear rate: that is, increasing the shear rate reduced thrombogenesis related to the intrinsic clotting pathway. An ACT of 200 to 250 seconds was suitable for in vitro antithrombogenic testing, and increasing the shear stress generated in the mechanical assist device reduced thrombogenesis via the intrinsic clotting pathway.
authors.affiliation: National Institute of Advanced Industrial Science and Technology (AIST), Ibaraki - Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Maruyama
authors.affiliation: National Institute of Advanced Industrial Science and Technology (AIST), Ibaraki - Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Kosaka
authors.affiliation: National Institute of Advanced Industrial Science and Technology (AIST), Ibaraki - Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Nishida
authors.affiliation: National Institute of Advanced Industrial Science and Technology (AIST), Ibaraki - Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Yamane
authors.affiliation: National Cerebral and Cardiovascular Center, Osaka - Japan.
authors.forename: Eisuke
authors.initials: E
authors.lastname: Tatsumi
authors.affiliation: National Cerebral and Cardiovascular Center, Osaka - Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Taenaka
mesh_terms: D000818:Animals; D001777:Blood Coagulation / Q000502:physiology*; D001780:Blood Coagulation Tests; D002417:Cattle; D002951:Citrates; D006353:Heart-Assist Devices; D010314:Partial Thromboplastin Time; D011517:Prothrombin Time; D013314:Stress, Mechanical
chemical_list: D002951:Citrates; C514290:trisodium citrate