Development of a new model of transvenous thrombosis in the pig superior sagittal sinus using thrombin injection and balloon occlusion.

PURPOSE

To establish an experimental model of superior sagittal sinus (SSS) thrombosis using a transvenous route, and thrombin and balloon occlusion, in pigs.

METHODS

The SSS was catheterized transvenously in six pigs. Thrombin was injected into the pigs' SSS to induce thrombosis. Magnetic resonance imaging (MRI) and magnetic resonance venography (MRV) confirmed successful SSS thrombosis. MRI and MRV were also used to observe the evolution of thrombus and accompanying brain parenchymal changes before thrombus induction postoperatively on Days 1, 3, and 7. The pigs were sacrificed for histological examination at the follow-up.

RESULTS

SSS thrombosis was successfully achieved in all six pigs. On Day 1 postoperatively, MRV confirmed SSS thrombosis and MRI revealed brain edema in each animal. On Day 3, venous infarction was noted in two cases, one of which appeared to be hemorrhagic. On Day 7, MRV showed partial recanalization of the SSS in one pig. Brain edema was significantly relieved in four cases while, in two other cases, the extent of venous infarction was reduced. Histological examination confirmed SSS thrombosis in all animals, with recanalization in only one case. In two of the animals, bilateral parasagittal infarction was seen, including one with petechial hemorrhage. In the other four animals, bilateral parasagittal edema was observed.

CONCLUSION

The development of an experimental model of SSS via the transvenous route is feasible in pigs using thrombin and balloon occlusion. This model closely resembles SSS thrombosis in humans, and can be applied in the clinical study of this phenomenon as well as in clinical therapeutic applications.