Plaque removal and thrombus dissolution with the photoacoustic energy of pulsed-wave lasers-biotissue interactions and their clinical manifestations.

Pulsed-wave lasers ablate atherosclerotic plaque and dissolve coronary thrombus by emission of photoacoustic energy initiating photomechanical, photochemical and photothermal transformation. The newly discovered process of 'inertially confined ablation' ascribes to pressure generation and plaque vaporization during lasing. Tremendous pressure within the lased plaque and gas bubble formation account for adverse clinical manifestations such as perforations, acute vessel closure and dissections. Pulsed-wave lasers can be applied for selected patients with lesions considered 'nonideal' for balloon angioplasty who present with acute ischemic syndromes. Due to strong optical absorption by thrombi in the ultraviolet (excimer), visible (dye), and mid-infrared (holmium) wavelengths, these lasers can also dissolve clots and therefore serve as an emerging option in patients with complicated acute myocardial infarction who fail to respond to thrombolytic drugs and exhibit thrombotic lesions deemed unsuitable for standard balloon angioplasty.