Abstract
Background and Objective
There are several problems inherent in the treatment of cerebral embolisms, such as the narrow therapeutic time window and the severe side effects of fibrinolytic drugs. There is thus need of a new method of removing a cerebral thrombus more rapidly using smaller amounts of fibrinolytics.
Study Design/Materials and Methods
The liquidโjet generator was made by insertion of an optical fiber (diameter: 0.6 mm) into a balloon catheter (6 Fr). A pulsed holmium (Ho) YAG laser (pulse duration timeโ=โ350 ยตs) was used as a laser source. The maximum penetration depth of a liquid jet generated with this device into a gelatin artificial thrombus was measured at various standโoff distances (L; distance between the optical fiber end and the catheter exit). Based on the result, a standโoff distance of 13 mm was chosen to investigate the enhancement of urokinase (UK) efficacy by only a single operation of the liquidโjet device in artificial thrombi made of human blood.
Results
Maximum penetration depth increased in proportion to L and reached a maximum value (9 mm) when L was around 13 mm. Fibrinolysis rates (%) after incubation with a small amount of UK for 10 and 30 minutes were predominantly raised by a single use of the laserโinduced liquid jet (5.4โยฑโ2.4 vs. 22.6โยฑโ6.1 and 7.3โยฑโ3.8 vs. 38.3โยฑโ5.6, respectively (meanโยฑโSD, Pโ<โ0.001)).
Conclusions
A laserโinduced liquid jet effectively promoted fibrinolysis in vitro with use of only a small amount of fibrinolytics. Lasers Surg. Med. 29:360โ368, 2001. ยฉ 2001 WileyโLiss, Inc.