MICROSECOND LASER-ABLATION OF THROMBUS AND GELATIN UNDER CLEAR LIQUIDS - CONTACT VERSUS NONCONTACT

Laser thrombolysis is a procedure for removing blood clots in occluded arteries using pulsed Laser energy. The laser light is delivered thro ugh an optical fiber to the thrombus. The ablation process is profound ly affected by whether the optical fiber tip is inside a catheter or i s in contact with the thrombus, This study measured ablation efficienc y of 1-mu s laser pulses to remove a porcine clot confined in a silico ne tube. The cavitation process was investigated by visualizing laser- induced bubble formation on gelatin targets with Bash photography and measuring the acoustic transients with a pressure transducer, The lase r spot size did not affect the mass of material removed. The efficienc y of the contact ablation was at least three times greater than that o f the noncontact ablation. Finally, the mass removed was closely corre lated with the measured bubble expansion pressure.