Selective RF heating of resonant stent toward wireless endohyperthermia for restenosis inhibition

This paper reports a novel active stent targeted at the application to endohyperthermia treatment for in-stent restenosis problems. The stainless-steel stent designed to function as an electrical inductor is integrated with a flexible capacitor strip to form a resonant circuit, which serves as a frequency-selective wireless heater controlled using a tuned radio-frequency (RF) magnetic field applied externally. The fabricated stent device with the initial diameter of 2 mm is expanded up to 6 mm in diameter inside an artificial artery using a balloon catheter. The expanded device is revealed to show efficient heat generation with temperature rise of >30 °C when resonated using an RF power of 320 mW. Temporal and frequency characteristics are evaluated to demonstrate rapid heating ability with strong frequency sensitivity. These promising results validate the feasibility of wireless stent hyperthermia that potentially offers a novel therapeutic path to long-term inhibition and management of stent restenosis.