Utility of coronary orbital atherectomy with guide‐extension system for distally located undilatable in‐stent restenosis: A case report

Orbital atherectomy (OA) may be effective in managing undilatable in‐stent restenosis (ISR) despite off‐label indications. We demonstrated that optical frequency domain imaging (OFDI)‐guided OA, with a guide‐extension system was effective even in distally located, undilatable ISR. However, OFDI revealed that inter‐struts calcified neoatherosclerosis remained a challenging issue. OFDI‐guided OA, with a guide‐extension system, could be useful for the treatment of distally located, undilatable ISR with hard neointima and calcified neoatherosclerosis, while preventing potential OA‐related complications, such as crown entrapment.