Usefulness of excimer laser atherectomy for balloon uncrossable lesion in chronic total occlusion

Excimer lasers are pulsed gas lasers that use a mixture of a rare gas and halogen as the active medium to generate pulses of short-wavelength, high-energy ultraviolet light. [1] Irradiction to atherosclerotic coronary artery segments allows the culprit lesions to transpirate without heat damaging the normal tissues. We described an effective case of excimer laser coronary atherectomy (ELCA) for a device-uncrossable chronic total occlusion (CTO) lesion below. A 77-year-old male was found to have a large ischemic defect and redistribution in the inferior wall that was revealed by myocardial perfusion scintigraphy before cerebrovascular surgery. The patient was suspected to have ischemic heart disease, and was transferred to our institution. A coronary angiography (CAG) revealed nonocclusive disease of his left coronary system along with a CTO of the right coronary artery (RCA) (Fig. 1A); he was diagnosed with silent myocardial ischemia (SMI), and percutaneous coronary intervention (PCI) was performed. We performed PCI for the CTO lesion after cerebrovascular surgery because we diagnosed stable ischemic heart disease. A 6 French approach was adopted (JR4.0 guide for the RCA). An antegrade approach was selected because of a lack of appropriate collateral branches for a retrograde approach. A GAIA first guidewire (Asahi Intecc Co. Ltd., Nagoya, Japan), with the support of an Asahi Corsair microcatheter (also called channel dilator, Asahi Intecc Co. Ltd., Nagoya, Japan), was crossed into the distal site of the occluded lesion (Fig. 1B). However, a Corsair microcatheter, Sapphire II balloon 1.0 × 5.0 mm (Orbusneich Medical, Tokyo, Japan) and Tornus 2.6Fr (penetration catheter, Asahi Intecc Co. Ltd., Nagoya, Japan) were not able to pass the lesion. Thereafter, although we tried mother and child technique [2] and buddy wire technique, both techniques failed. Eventually, perforation in the distal RCA lesion by the guidewires was confirmed (Fig. 1C). However, no findings indicated cardiac tamponade and the hemodynamics were not disrupted; all procedures were terminated because of potent concerns of cardiac tamponade. After 17 months, a second PCI attempt was performed. Single right femoral access was obtained, and a 7Fr AL1.0 SH guiding catheter with side holes (Cordis Corporation, Warren, NJ, USA) was used. Although a GAIA first guidewire, with the support of an Asahi Corsair microcatheter, was crossed into the distal site of the occluded lesion similar to a previous procedure, CAG revealed that the GAIA first guidewire was suspected of crossing a pseudolumen. After withdrawing the Corsair microcatheter, Navifocus WR intravascular ultrasound (IVUS) system (Terumo Corp., Japan) [3] was performed through the GAIA first guidewire in that it was suspected to be in the pseudo-lumen. Referencing the IVUS images, a GAIA second guidewire (Asahi Intecc Co. Ltd., Nagoya, Japan) crossed the CTO lesion through a different pathway by an