Laser ablation of human atherosclerotic plaque without adjacent tissue injury

Abstract

Seventy samples of human cadaver atherosclerotic aorta were irradiated in vitro using a 308 nm xenon chloride excimer laser. Energy per pulse, pulse duration and frequency were varied. For comparison, 60 segments were also irradiated with an argon ion and an Nd:YAG (neodymium:yttrium aluminum garnet) laser operated in the continuous mode. Tissue was fixed in formalin, sectioned and examined microscopically. The Nd:YAG and argon ion-irradiated tissue exhibited a central crater with irregular edges and concentric zones of thermal and blast injury. In contrast, the excimer laser-irradiated tissue had narrow deep incisions with minimal or no thermal injury. These preliminary experiments indicate that the excimer laser vaporizes tissue in a manner different from that of the continuous wave Nd:YAG or argon ion laser. The sharp incision margins and minimal damage to adjacent normal tissue suggest that the excimer laser is more desirable for general surgical and intravascular uses than are the conventionally used medical lasers.

Vaporizing Thrombus With Excimer Laser Before Coronary Stenting Improves Myocardial Reperfusion in Acute Coronary Syndrome

“…14, 27 Recent clinical experience in patients presenting with acute ischemic-thrombotic coronary syndromes has shown that ELCA is capable of efficient plaque debulking, thrombus vaporization, and facilitation of adjunct balloon angioplasty and stenting. 10-12 In terms of tissue-level reperfusion in patients with AMI, a previous report demonstrated that the use of ELCA achieves a higher rate of STR, which is a good predictor of tissue reperfusion, than does balloon angioplasty.…”

Physical aspects of excimer laser angioplasty for undilatable lesions

“…Original experiments carried out in air [8] attributed the mechanism of tissue ablation to the nonthermal process of photochemical bond breaking, but this was later disputed by studies in aqueous media showing that the predominant effect of excimer laser angioplasty involves a thermomechanical process of rapidly expanding and imploding vapor bubbles [6,7,[9][10][11]. Protein and nucleic acid chromophores absorb ultraviolet light at 308 nm and transfer heat to tissue water [12].…”

<b>Effects of Excimer Laser on Vascular Prosthetic Materials: A Preliminary Study for the Laser Treatment of Prosthetic Graft Failur</b><b>e </b>

“…The different mechanism of action of the excimer laser 15,19,20) as opposed to conventional thermal lasers 21,22) also positions this devise as a potentially useful tool in salvage of the failing graft. The technique of laser ablation, however, even with the excimer laser is not precise enough at the present time to accurately control direction and depth of injury.…”