Subintimal excimer laser coronary atherectomy (S-ELCA) as a bail-out for device-uncrossable chronic total occlusion: case report

Chronic total occlusion (CTO) that cannot be crossed with balloons or microcatheters despite successful guidewire passage represent one of the most challenging scenarios in percutaneous coronary intervention (PCI). Excimer laser coronary angioplasty (ELCA) is an established adjunct for device-uncrossable lesions; however, the safety of its application within the subintimal space remains limited.

A 67-year-old male with a complex cardiac history, including prior recurrent interventions and coronary artery bypass grafting, was referred for staged PCI of a right coronary artery CTO because of refractory angina (Canadian Cardiovascular Society class III). Following successful antegrade subintimal wire tracking and re-entry using a Stingray balloon, multiple ultra-low-profile balloons and dedicated microcatheters failed to traverse the subintimal-to-true-lumen transition. A 0.9-mm ELCA catheter at 80 mJ/mm² and 80 Hz was used in the subintimal space without saline flush, successfully creating a traversable channel. Complete revascularization was achieved using six overlapping drug-eluting stents, optimized with intravascular ultrasound guidance. At two-year follow-up, repeat intravascular ultrasound demonstrated vascular healing at the subintimal-re-entry interface.

This case demonstrates the potential safety and feasibility of subintimal ELCA (SELCA) as a bail-out for device-uncrossable lesions during antegrade dissection re-entry of CTO-PCI, with the first reported evidence of vascular healing at the subintimal laser site at two-year follow-up.