MRCP2-0169
A 63-year-old man presents to his GP with complaints of leg pain. He has been experiencing a crampy uncomfortable feeling in the back of both of his calves when he walks to the shops over the last few months. The discomfort is so severe that he has to stop and rest for a few minutes, after which he notices an improvement in his symptoms. He also experiences these symptoms when he is shopping in the supermarket. He attributes this to overexertion and tries to rest on his shopping trolley while walking, but it does not seem to help. He has a 35-pack year smoking history and takes amlodipine for his blood pressure, and paracetamol and ibuprofen for lower back pain that has troubled him for years.
During the physical examination, the doctor observes mild atrophy of his thigh and calf muscles bilaterally, in addition to shiny pale skin with significant hair loss throughout his lower limbs. His pedal pulses are bilaterally impalpable, and popliteal pulses are faint. Power in both lower limbs is normal throughout all movements, and he has normal patellar reflexes bilaterally and absent ankle reflexes. His Babinski reflex is downgoing on the left side and equivocal on the right side. A recently obtained ankle brachial pressure index test yielded a result of 0.70 on the right side and 0.95 on the left side. X-rays of his lumbar spine show evidence of joint space narrowing and osteophytes.
What is the most appropriate next step in the management of this patient?