Individual propensity for thrombosis: comparison of venous and arterial circulations.
BACKGROUND
The pathogenesis of venous thrombosis has been attributed to complex interaction between environmental and inherited variables. A basal predisposition for venous thrombophilia independent of environmental variables has not been previously defined experimentally. Both to address the existence of an individual propensity to venous thrombosis and to establish an animal model in which variables governing this propensity could be tested, we provoked venous thrombi in a cohort of pigs of uniform size and age. We furthermore sought to determine whether the thrombotic propensity in the venous circulation is associated with similar propensity for arterial thrombosis.


METHODS
Bilateral iliac venous stents were deployed and 2 h later, thrombi were harvested and weighed. The thrombotic response was compared to carotid arterial thrombi generated by crush injury within the same pig. Venous and arterial thrombus platelet deposition were measured by scintillation detection of autologous (111)In-platelet content.


RESULTS
In a cohort of 27 pigs, venous thrombus weights and platelet content varied over greater trrhan 10-fold range from least to greatest responders. There was strong intra-individual correlation of thrombus platelet deposition (r=0.86; p=0.008) and thrombus weights (r=0.68; p=0.015) between stented iliac vein pairs. Venous thrombosis correlated with whole blood platelet counts but not carotid platelet-rich thrombus formation.


CONCLUSIONS
The wide variation in venous thrombotic response to a standardized injury appears to represent an intrinsic propensity of the individual. The poor correlation with arterial thrombosis implies unique mechanisms responsible for this propensity in arteries and veins.
Section of Hematology Research Mayo Clinic, Rochester, MN 55905, USA.
Waldemar
W
Wysokinski
Krzysztof
K
Karnicki
Robert D
RD
McBane
D000818:Animals; D001792:Blood Platelets / Q000502:physiology; D002339:Carotid Arteries / Q000502:physiology; D002341:Carotid Artery Thrombosis / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D004195:Disease Models, Animal; D005260:Female; D007084:Iliac Vein / Q000502:physiology; D007205:Indium Radioisotopes; D010976:Platelet Count; D011877:Radionuclide Imaging; D015607:Stents; D034421:Sus scrofa; D020246:Venous Thrombosis / Q000000981:diagnostic imaging* / Q000503:physiopathology*
D007205:Indium Radioisotopes