Background: Thrombotic ischemic stroke affects over 400,000 people in the United States annually and a third leading cause of mortality. Thrombolysis in occluded arteries may reduce brain injury if it is performed before infarction. t-PA an endothelial serine protease infusion is accepted method of thrombolysis for acute stroke. t-PA effect can be slow and not always successful. Endovascular Vibration has been used to treat peripheral thrombosis. Externally applied Vibroacoustic Stimulation (VATS) has been shown to provide reliable transmissibility to the internal arteries.
Objective: We hypothesized that non-invasive externally applied VATS may enhance t-PA effect and accelerate thrombolysis.
Methods: In vitro simulation of arterial thrombosis was performed using silicon tubes and porcine coronary arteries. Fresh clot was produced by drawing an aliquot of blood and it’s immediate incubation with thrombin for 1 hr at 37oC. Clots were placed within a silicon tubing or pig coronary artery segment filled with saline solution (n=4 per group). t-PA was added into solution at 0.015 mg/mL concentration corresponding to clinically used dose for emergency thrombolysis in stroke. VATS was applied to external surface of tubing or artery at 100 Hz, 20 dyn/cm2 for 15 min. Thrombolysis time and degree of clot dissolution was monitored.
Results: VATS significantly improved t-PA thrombolytic effect (t-PA/VATS, 60%) in comparison to the t-PA alone (t-PA, 35%) (p<0.001). The presence of endothelial cells in coronary vessel did not affect t-PA or t-PA/VATS treatment outcome.
Conclusions: Our study confirms that VATS at 100 Hz applied externally to a clotted lumen enhances t-PA clot dissolution. The effects of t-PA or t-PA/VATS are endothelial independent. VATS may offer safe noninvasive adjunct to thrombolytic drug therapy for emergency acute stroke. Further, in vivo studies are warranted.