Development of a new technique for reducing pressure pulse generation during 308-nm excimer laser coronary angioplasty.

Despite expectations that excimer laser ablation would result in a low incidence of coronary dissection, studies have documented a 15-20% incidence of dissection (including a 4-6% incidence of clinically significant dissection) during excimer interventions. This investigation sought to determine if pressure pulses produced by the exposure of fluid phase media (blood and contrast) to 308-nm excimer radiation might contribute to untoward outcomes. Pressure pulses generated in these media were quantitated to be > 100 atm. In vitro ablation of porcine aorta in the presence of blood or contrast resulted in tissue dissection, while ablation in pure crystalloid did not. Next, a "flush and bathe" technique designed to replace all blood and contrast with crystalloid was applied to a pilot population of 57 consecutive patients. There were no rhythm disturbances or laser-related clinically significant dissections in this group, and the clinical success rate was 95%. In summary, this report quantitates a potential etiology for excimer dissection and suggests that replacement of blood and contrast with crystalloid might improve procedural and clinical success rates.

Excimer laser angioplasty.

Excimer laser angioplasty is one of the newest procedures being used in interventional cardiology. Because of persistently high rates of restenosis with conventional balloon angioplasty (which may be attributed to the acceleration of atherosclerosis by remodeling and dilatation of diseased arteries) alternatives to remove and debulk atheromatous plaque are being explored. Among these, excimer laser angioplasty (ELA) has been developed as a modality that offers an alternative to percutaneous transluminal coronary angioplasty. The laser energy is delivered via fiberoptics to the target lesion and the plaque material is rendered into a gaseous state (vaporized) by breaking the molecular bonds. With proper training and patient selection, ELA has complication rates that are no higher than conventional balloon angioplasty. Preliminary data indicate that the laser is most successful in treating lesions that are not well treated with conventional balloon angioplasty. These include saphenous vein graft lesions, aorto-ostial lesions, long lesions (> 10 mm in length), moderately calcified stenoses, total occlusions, and percutaneous transluminal coronary angioplasty dilitation failures. The purpose of this article is to review the history and physics of ELA and to provide the nursing professional with an understanding of how the procedure is performed. Nursing considerations when caring for the patient undergoing this procedure are provided.