Effects of microbubbles on transcranial Doppler ultrasound-assisted intracranial urokinase thrombolysis

Introduction: To evaluate the efficacy of microbubbles in transcranial Doppler ultrasound (TCD)-assisted urokinase thrombolysis.

Materials and methods: Male New Zealand white rabbits (N=32) were randomly divided into 2 groups, a urokinase group and a combined urokinase plus microbubble group. The middle cerebral artery (MCA) was occluded by injecting autologous blood clots through the carotid artery. In the urokinase plus microbubble group, sulfur hexafluoride (SonoVue) microbubbles were injected intravenously immediately after intravenous injection of urokinase. The 2 groups were monitored by TCD from before until 2h after thrombolysis, and the hemodynamic changes and infarct size were recorded.

Results: The urokinase alone group had 1 case of complete recanalization and 4 cases of partial recanalization (recanalization rate, 31.3%). The urokinase plus microbubble group had 3 cases of complete recanalization and 6 cases of partial recanalization (recanalization rate, 56.3%). The average size of the infarction foci was 13.9% in the urokinase group and 9.1% in the urokinase plus microbubble group (P=0.025). Pathological examination revealed no cerebral hemorrhage in either group.

Conclusions: The addition of microbubbles enhanced the effects of transcranial Doppler ultrasound-assisted urokinase thrombolysis.