Laser balloon angioplasty: potential clinical applications

Coronary laser balloon angioplasty (LBA) is a new technique which permits application of heat (generated by the laser source) and pressure (by balloon inflation) to thermally weld tissue during coronary angioplasty (PTCA). The goal of LBA is to achieve a large, smooth arterial lumen, by thermal welding of dissection flaps, elimination of elastic recoil, elimination of vasospasm, reduction in platelet activation, desiccation of thrombus, and inhibition of smooth muscle cell proliferation (Table 1). The LBA system consists of a 50 watt continuous wave Nd:YAG laser with a wavelength of 1060 nm, and a modified coronary balloon angioplasty catheter with a 4.3 French shaft and a PET balloon measuring 20 mm in length and 2.5, 3.0 and 3.5 mm in diameter. For clinical use, laser doses ranging from 250 to 450 joules each are delivered over 20 seconds, to achieve adventitial tissue temperatures of 90 to 110 degrees C. The LBA technique is quite similar to that of conventional PTCA. The LBA catheter is usually positioned over a 0.014" guidewire through an 8 French guiding catheter. Once the laser balloon is in position, the balloon is inflated to a pressure of 4 atmospheres and the programmed laser dose is delivered over 20 seconds, followed by continued balloon inflation for an additional 20 to 40 seconds while the temperature of the arterial wall returns to normal. Conventional PTCA is virtually never necessary to improve lumen appearance and dimensions after LBA. LBA has been shown to be effective in the management of acute failure of PTCA, due to abrupt closure or severe dissection with impaired flow ("impending closure").(ABSTRACT TRUNCATED AT 250 WORDS)