@article{shangguan97b,
  author = {H. Shangguan and L. W. Casperson and S. A. Prahl},
  title = {Contact versus Non-contact Ablation Efficacy of Thrombus in an Aqueous Environment},
  journal = {Lasers Surg. Med.},
  volume = {S9},
  pages = {10},
  year = {1997 abstract only},
  abstract = {Laser thrombolysis is a procedure for removing blood clots in occluded arteries using pulsed laser energy. The laser light is transmitted through an optical fiber to the thrombus. The ablation process is profoundly affected by whether the optical fiber tip is inside a catheter or in contact with the thrombus. \vskip2mm We measured the ablation efficiency (mass removed/pulse energy) of 1\,$\mu$s pulsed 577\,nm light to remove porcine thrombus in 3\,mm silicone tubes. Laser pulses were delivered via a 1\,mm catheter with a 200--400 mm quartz fiber inside. Contact experiments used 10--25\,mJ/pulse; non-contact experiments used three times as much. The spot sizes were 200--400\,$\mu$m for contact ablation and 450--520\,$\mu$m for non-contact ablation. Distilled water or saline was injected through the catheter at a flow rate 4\,mL/min to wash away the ablated clot. \vskip2mm The contact ablation efficiency ranged from 6--18\,$\mu$g/mJ and the non-contact ablation efficiency ranged from 2--6\,$\mu$g/mJ depending on the particular porcine clot ablated. However, the contact ablation efficiency was always about 3 times greater than the non-contact ablation efficiency. All efficiencies were independent of laser energy and fiber size. Finally, we observed that the bubble sizes and acoustic pressures generated by the contact delivery were smaller than those caused by non-contact delivery.},
}