Initial experience of a single referral centre using excimer laser coronary atherectomy-assisted expansion in undilatable stents: Excimer laser in undilatable stents.

Aims: Undilatable stents with severe peri-stent calcification are an important cause of target lesion failure and therapeutic options are limited. We report our initial experience with the safety and efficacy of excimer laser coronary atherectomy (ELCA)-assisted expansion of undilatable stents. Methods and results: ELCA was performed with saline, blood and contrast-enhanced trains. All lesions were post-dilated at high pressures and treated with a drug-eluting balloon. Thirty-one lesions with undilatable stents were included at a single centre with experienced operators from March 2016 to February 2021. The mean number of prior procedures for in-stent restenosis was three and 14 lesions had multiple layers of stent. Procedural success (>50% increase in minimal stent diameter [MSD]) and adequate stent expansion (MSD >70% of reference vessel diameter) was achieved in all lesions. At six-month follow-up (N=26 lesions), there were six periprocedural myocardial infarctions due to slow flow, two cardiac deaths and one target lesion revascularisation. There were no perforations. Conclusions: Our niche experience at a centre with experienced operators demonstrated that ELCA led to larger final lumen and stent dimensions in highly selected patients with undilatable stents and recurrent restenosis at the cost of relatively frequent slow flow.