In-stent restenosis. Acute and long-term outcomes after excimer laser coronary angioplasty

The Excimer Laser: Science Fiction Fantasy or Practical Tool?

Nearly 20 years ago, in vitro experiments left no doubt about the fact that laser light can ablate atherosclerotic plaque. The initial enthusiastic results with the technology, particularly in coronary arteries, were followed by reports showing unacceptably high restenosis and complication rates. These poor results were due to the premature application of an underdeveloped technology, a lack of understanding of laser/tissue interaction, and the use of incorrect lasing techniques. Consequently, and without discrimination, all lasers were banned from the catheterization laboratories for nearly a decade. Technological enhancements of the excimer laser, combined with refined catheter lasing techniques, resulted in greater debulking of atherosclerotic material in long superficial femoral artery occlusions. These results triggered the application of the excimer laser technique as an atherectomy tool in more complex lesions below the knee. The multicenter Laser Atherectomy for Critical Ischemia study clearly demonstrated that the excimer laser technology resulted in limb salvage rates >90% in patients with critical limb ischemia (CLI). Furthermore, new clinical results indicate that the excimer laser is very effective in dissolving thrombotic obstructions, redirecting this technology to the coronary field.

The results of the excimer laser in CLI validate the role of the cool laser in treating complex peripheral vascular disease. The results suggest a larger indication for this technology and support a more aggressive use of these interventional techniques in the treatment of this large patient cohort. However, all lasers are not equally effective in debulking atherosclerotic material. Only the athermic process associated with the excimer laser produces a safe and effective endovascular ablation of obstructive atherosclerotic and/or thrombotic material. The appropriate and safe utilization of the equipment and lasing techniques, combined with correct indications and patient selection, will contribute to the successful application of laser-assisted atherectomy in complex peripheral and coronary artery obstructive disease. Unfortunately, little consistent scientific data has been generated to convince the interventional community of the usefulness of excimer laser ablation.

The excimer laser: science fiction fantasy or practical tool?

Nearly 20 years ago, in vitro experiments left no doubt about the fact that laser light can ablate atherosclerotic plaque. The initial enthusiastic results with the technology, particularly in coronary arteries, were followed by reports showing unacceptably high restenosis and complication rates. These poor results were due to the premature application of an underdeveloped technology, a lack of understanding of laser/tissue interaction, and the use of incorrect lasing techniques. Consequently, and without discrimination, all lasers were banned from the catheterization laboratories for nearly a decade. Technological enhancements of the excimer laser, combined with refined catheter lasing techniques, resulted in greater debulking of atherosclerotic material in long superficial femoral artery occlusions. These results triggered the application of the excimer laser technique as an atherectomy tool in more complex lesions below the knee. The multicenter Laser Atherectomy for Critical Ischemia study clearly demonstrated that the excimer laser technology resulted in limb salvage rates >90% in patients with critical limb ischemia (CLI). Furthermore, new clinical results indicate that the excimer laser is very effective in dissolving thrombotic obstructions, redirecting this technology to the coronary field. The results of the excimer laser in CLI validate the role of the cool laser in treating complex peripheral vascular disease. The results suggest a larger indication for this technology and support a more aggressive use of these interventional techniques in the treatment of this large patient cohort. However, all lasers are not equally effective in debulking atherosclerotic material. Only the athermic process associated with the excimer laser produces a safe and effective endovascular ablation of obstructive atherosclerotic and/or thrombotic material. The appropriate and safe utilization of the equipment and lasing techniques, combined with correct indications and patient selection, will contribute to the successful application of laser-assisted atherectomy in complex peripheral and coronary artery obstructive disease. Unfortunately, little consistent scientific data has been generated to convince the interventional community of the usefulness of excimer laser ablation.

Area ablation: a new lasing concept provides significantly enhanced acute and long-term results for treatment of in-stent restenosis

BACKGROUND AND OBJECTIVES

Debulking is still a technique of choice for in-stent restenosis (ISR). Excimer laser debulking has enabled high procedural success with very low complication rates, but has demonstrated markedly heterogeneous results owing to differences in lasing and laser technology, and selected patient populations. Since new area-ablation technique enables ablation of larger areas than its own device size, we have evaluated their effectiveness and safety in an uncontrolled study.

STUDY DESIGN/MATERIALS AND METHODS

Fifty-three patients with diffuse ISR were treated by laser area ablation, followed by adjunctive balloon angioplasty. Primary endpoint was percent of binary stenosis at 6-month follow-up; secondary endpoints were procedural success; target lesion revascularization (TLR); major adverse cardiac events (MACE); diameter stenosis (DS); and minimal lumen diameter (MLD) before and after laser debulking, and at 6-month follow-up.

RESULTS

Laser debulking was feasible (as defined as < or =30% residual stenosis) in 98.1% of patients. At 6-month follow-up, binary stenosis was 26.4%; angiographic TLR, 20.7%; and MACE, 3.7%. DS decreased from 87+/-17% to 20 +/- 9% after laser debulking, and to 9+/-7% after PTCA; it was 29+/-14% at follow-up (P-values in comparison to baseline: 0.0047; 0.0036; 0.0064). MLD increased from 0.6+/-0.3 to 2.4+/-0.5 mm after laser debulking, to 2.8+/- 0.6 mm after adjunctive PTCA, and to 1.9 +/- 0.4 mm at follow-up (P-values in comparison to baseline: 0.0059; 0.0031; 0.0088).

CONCLUSIONS

Owing to a significantly greater MLD, area ablation facilitates significantly enhanced immediate and follow-up results for diffuse ISR, including a simpler and more effective laser-debulking procedure than former lasing techniques.