Aneurysm of a persistent sciatic artery.

Angiographic examination in a patient with sciatic-like pain on the right side and a firm, pulsatile, non-tender mass in the right buttock revealed a large sciatic artery aneurysm. The aneurysm was successfully resected at surgery. The primitive sciatic artery is the main arterial supply to the lower extremities in the 9-mm embryo. Its persistence, while very rare, is of clinical significance because of the tendency for aneurysms to develop in the artery. Surgical resection is indicated in sciatic artery aneurysms because of the danger of rupture or embolic occlusion of arteries distal to the aneurysm.