Prototype therapeutic ultrasound emitting catheter for accelerating thrombolysis.

The aim of this study was to evaluate the performance of a new therapeutic ultrasound device for accelerating thrombolysis by urokinase. Artificial thrombi were produced in vitro by Chandler's loop method. Urokinase (240 IU) was added to the artificial thrombi (n = 5) before exposure to ultrasound with the new catheter‐delivered device. Ultrasound (1.3 MHz) was applied with an intensity of 0.3 W/cm2 for 60 s. The degree of fibrinolysis was obtained by measurement of thrombus weight and calculated as percentages. Fibrinolysis was compared between control thrombus groups (n = 5) treated with urokinase alone or with ultrasound alone (analysis of variance, P < 0.05). Ultrasound plus urokinase (33.1 +/‐ 6.1% [mean +/‐ standard deviation]) was significantly different urokinase alone (12.3 +/‐ 2.4%) after 15 min of incubation. Ultrasound alone resulted in no fibrinolysis (0.9 +/‐ 2.5%). Ultrasound energy from the catheter‐based device was sufficient to induce acceleration of fibrinolysis with urokinase.

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