Giant aneurysmal degeneration after subintimal fluoropolymer-coated paclitaxel-eluting stent implantation for the superficial femoral artery occlusion: a case report.

Background: Drug-eluting therapies remarkably reduce the incidence of restenosis and have revolutionized endovascular strategies for femoropopliteal lesions in patients with peripheral artery disease, nevertheless, concerns have arisen over the risk of aneurysmal degeneration after using an Eluvia polymer-based drug-eluting stent (DES). Case summary: We present a case of an 80-year-old male who developed a giant aneurysm long-term after Eluvia implantation. He noticed a pulsatile mass in his thigh without any decrease in the ankle-brachial index 27 months after subintimal DES placement for superficial femoral artery (SFA) chronic total occlusion. Duplex ultrasonography (DUS) showed a giant cavity outside the vessel and a to-and-fro flow between the cavity and the SFA at the Elvia stents overlapped in the subintimal space. Endovascular-covered stents successfully sealed the cavity and reduced the size of the aneurysm at follow-up DUS. Discussion: The aneurysmal degeneration, the so-called 'low echoic area' around the stent by ultrasound, is a relatively common finding after Eluvia DES implantation. It is thought to have little association with clinical events up to 2 years, however, the nature of this phenomenon remains unclear, and some cases present with clinical worsening. In this case, the development of a giant aneurysm could be induced by the overlapping stent not only by the local drug and polymer overdose but also by the increased mechanical force exerted against the fragile outer wall of the subintimal structure.