Applicability of laser to assist coronary balloon angioplasty

Abstract

Severe atherosclerotic obstructed coronary artery disease (CAD) may preclude passage of a balloon catheter for transluminal coronary angioplasty (TCA). Since lasers have been shown to effectively vaporize CAD plaque, the initial application of laser to effect a lumen large enough to accomodate the angioplasty catheter for further dilatation was explored. Eleven postmortem human CAD segments which did not permit passage of a 1.33 mm shaft diameter angloplasty catherer were studied. Argon laser radiation (14 to 90 J) transmitted via 400 μm core diameter quartz fiber onto the stenotic channel of 0.58 mm created a vaporized lumen of 1.77 mm (mean increase of 1.31 ± 0.25 mm,p < 0.001). The laser procedure allowed the balloon angioplasty catherer to be pushed into the stenosis. TCA was then performed (7 atm, 45 seconds) and expanded the channel to 2.12 mm (additional mean increase of 0.38 ± 0.07 mm,p < 0.001). In terms of percent luminal narrowing, laser radiation reduced obstruction from 80% to 45% (mean difference of −38.7 ± 4.6%,p < 0.001), and TCA caused a further decrease to 37% (mean difference of −9.3 ± 1.9%,p < 0.001). Thus, in tight atherosclerotic lesions, the laser may be useful in creating an initial opening enabling the placement of the balloon angioplasty catherer which, in turn, can further dilate the lased stenotic coronary lumen.