Summary

A 68-year-old male presented with an asymptomatic pulsatile swelling on the back of his left thigh. Angiography revealed this to be aneurysmal degeneration of a persistent sciatic artery (PSA), an embryological variant whereby the primitive vascular tree persists as the main blood supply to the lower limb. Initial treatment was with an inlay graft to exclude the aneurysm from the circulation. The patient was re-referred 12 years later with a pulsatile swelling distal to the old scar. Angiography showed a popliteal artery aneurysm separate to both the sciatic artery and the anastomosis. The second procedure fashioned an inlay graft from the original graft down to the distal popliteal artery. The patient remains under follow-up. Patients with a PSA are prone to aneurysmal degeneration, which may also occur in adjacent vessels. For this reason, the authors recommend these individuals are kept under lifelong follow-up.