A 58-year-old patient complains of pain in the lower left extremity, which aggravates during walking, and sensation of cold and numbness in the both feet. The patient has been suffering from this condition for 6 years. Objectively: the skin is pale and dry, with hyperkeratosis. On the left shin hair is scarce. Pulse cannot be detected over the pedal and popliteal arteries and is weakened over the femoral artery. On the right limb pulsation of the popliteal artery is retained. What is the most likely diagnosis?