Bilateral persistent complete sciatic artery.
A case with persistent sciatic artery (PSA) was found in a cadaver of a 65-year-old female during a medical gross anatomy course. The artery was bilateral and complete and provided the major blood supply to both lower extremities. The vessel arose from the internal iliac artery that was extremely large bilaterally. The sciatic artery passed out of the pelvis through the infrapiriform foramen and descended posterior to the sciatic nerve through the gluteal region. The sciatic nerve was considerably flattened out under the artery. Large articular branches arose from the part of the artery at the buttock just below the piriform muscle. The artery descended along the back of the thigh and was crossed obliquely posteriorly by the long head of the biceps femoris muscle. The sciatic artery continued as the popliteal artery located very superficially in the popliteal fossa. A companion vein, i.e., the sciatic vein, accompanied each artery. The right sciatic vein entered the pelvis posteriorly through the infrapiriform foramen, whereas the left perforated the quadriceps muscle from behind and joined the femoral vein anteriorly. There was a gracile superficial femoral artery bilaterally. The deep femoral arteries of both lower limbs were hypoplastic with slender circumflex branches. There were no macroscopic connections between the sciatic and the deep or superficial femoral arteries on either side. This anomaly should be kept in mind in the evaluation of patients with sciatic or buttock pain or palpable "pulsating" buttock mass. Persistent sciatic artery also could be a potential hazard during orthopedic manipulations, hip joint surgery, and renal transplant surgery.