An in vitro study on ultrasound-enhanced urokinase-mediated thrombolysis

Objective To evaluate whether therapeutic ultrasound, applied alone or with urokinase, may have a thrombolytic effect on blood clots in vitro, and the other factors influencing the urokinase-mediated thrombolysis. Methods Experiments were carried out in an in vitro blood clot model.The blood clots were divided into four groups as physiological solution group(NS), urokinase group(UK),physiological solution plus ultrasound group(NS + US), urokinase group plus ultrasound group(UK + US).After intervention of one hour in static 37 ℃ water bath, each group of blood clots was weighed. After that,the weight loss and thrombolysis rate of the blood clots in each group were calculated. To observe the impact of the age of the blood clots on urokinase-mediated thrombolysis rate, the thrombolysis rate of eight time points 3, 4, 5, 6, 7, 8, 9, 10 hours was tested. The time was determined from the blood drawn from the body to the initiation of thrombolysis test. Results In terms of thrombolysis rate, there was significant difference between UK group and UK + US group(LSD-t 12. 1, P ＜ 0.01), with a thrombolysis rate 29. 3% ±8. 2% and 37. 5% ±7. 9%, respectively. However, the difference of thrombolysis rate between NS group and NS + US group with a thrombolysis rate 13. 4% ±4. 4% and 14. 5% ± 5.4%, respectively,was not statistically significant with a P value of 0. 08(LSD-t 1.8). The age of the blood clots had a negative correlation to the thrombolysis rate to some extent. Conclusion Therapeutic ultrasound has a significant effect on thrombolysis in combination with urokinase rather than used alone. To a certain extent,the thrombolysis rate decreases with the age of blood clot. Key words: Ultrasounic therapy;  Urinary plasminogen activator;  Thrombolytic therapy;  In vitro