Low-frequency Ultrasound Through The Skull Solubilization In Vitro Experimental Study

Objective To observe the different effect of thrombolysis by the low-frequency External Therapeutic Ultrasound (ETUS) through the skull or not through the skull and uniting or not uniting with UK and by UK alone, equally to compare the results. To investigate ETUS at low frequency through the skull enhances thrombolysis in vitro and to evaluate its possibility in the clinical application. Methods Choosing the suitable experiment parameter was based on the result of one-way ONOVA and orthogonal experiment design. The sufficiently shrieked old age artificial thrombus was produced by drawing from the elbow vein in 20 healthy selected adult volunteers. Six artificial thrombus from one person dried by the neutral filter paper and weighted, then were partly put in the thin cliff polyethylene test tubes containing corresponding the intermediary liquid from the plasminogen lightly. According to the principles of randomized block design, the artificial thrombus were then divided into six groups:①NS(control group),②UK,③NS+ETUS,④ETUS+UK,⑤NS+ETUS+SK,⑥ETUS+UK+SK. After being irradiated by ultrasound according to the operating methods of the experiment for 40 minutes, they were then dired by the neutral filter paper and weighed. Fibrinolysis was determined by the percentage of weight loss thrombus.Results The percentage of clot lysis for each study group was as follows: saline control 8.88%±5.06% , UK alone 30.22%±6.97%, ETUS+NS 10.72%±4.93%(P﹥0.05 compared with saline control), ETUS+UK 50.14%±14.36%(P﹤0.01 compared with UK alone), ETUS+NS+SK 8.65%±3.01%(P﹥0.05 compared with saline control), and ETUS+UK+SK 42.18%±10.18%(P﹤0.01 compared with UK alone,P﹤0.01 compared with ETUS+UK).Conclusion Low-frequency ultrasound transmits well through the skull, and not harms to nerve cell, and can significantly enhance thrombolysis in vitro.