Efficacy and Safety of Cold Atmospheric Plasma Combined With Endovascular Intervention in Patients With Diabetic Foot Ulcers and Lower Extremity Arterial Occlusion

"CAP therapy will be administered once daily for the first five days and then every other day thereafter, for a total of 13 sessions. Each session will last approximately 25 minutes, as recommended by the manufacturer. During treatment, the affected limb will be enclosed in a sterile treatment bag, sealed with medical adhesive tape. The CAP device will operate in two sequential modes: a disinfection mode delivering ozone-rich (O₃) plasma-activated gas for 20 minutes, followed by a healing mode delivering nitric oxide (NO)-rich plasma-activated gas for 5 minutes. All procedures will be performed in accordance with the manufacturer's instructions and the device's standard operating protocol."

Participants in the placebo group will undergo a sham procedure, in which the electric field required for plasma generation will be disabled, so that no plasma will be produced. Only the operating sounds of the device will be simulated, ensuring blinding for both participants and clinical staff.

All patients will undergo successful infrapopliteal angioplasty, with less than 30% residual stenosis confirmed by digital subtraction angiography.