Case report: persistent bilateral complete sciatic artery associated with aneurysmal degeneration.

Persistent sciatic artery is a rare congenital anomaly, with few cases described in the literature. This study presents a case of this embryological variation observed in a patient's lower limb circulatory system. The anatomical description is based on a review of medical records and imaging exams. This case report describes a 63-year-old female patient admitted to the emergency department complaining of severe pain in the right lower limb, with a cold, pale extremity and ecchymosis on the dorsum of the foot. Duplex ultrasound showed no detectable flow in the anterior tibial and fibular arteries and a tardus parvus pattern in the posterior tibial artery. The patient developed loss of movement and fixed cyanosis in the right foot and was referred for urgent thromboembolectomy. However, adequate reperfusion was not seen after the procedure. Angiotomography was performed on the first postoperative day, showing bilateral persistence of the sciatic artery, with aneurysmal degeneration, partially thrombosed, and no opacification of the arterial system downstream of the aneurysm. By the third postoperative day, the patient had developed areas of dry necrosis in the limb, with no perfusion to the ankle, and underwent transfemoral amputation. Despite being a rare condition, it is of great clinical importance because of the high complication rates.