Persistent Sciatic Artery an Incidental Finding

Male, 43

Persistent Sciatic Artery

A 43-year-old male presented with a right leg ulcer. CT scan of the femur with contrast was performed to delineate soft tissue involvement. Incidentally found was a persistent sciatic artery (PSA).

Persistent Sciatic Artery

Sciatic arteries are the main blood supply to the lower limbs during fetal development. The sciatic artery eventually regresses leaving remnants which persist as popliteal and peroneal arteries. Prior to sciatic regression the popliteal and peroneal arteries establish continuity with the superficial femoral artery (1,2). Persistent sciatic artery is a direct continuation of the internal iliac artery. It is a rare anatomic variant where the sciatic artery does not regress during fetal development (1). There are four types of PSA. In type 1 and type 2, the PSA is completely present. The distinction between types 1 and 2 is that in type 1 there is a fully developed superficial femoral artery (SFA) and in type 2 the SFA is partially or completely absent. Our case is an example of type 2 PSA. Sciatic arteries are the main blood supply to the lower limbs during fetal development. The sciatic artery eventually regresses leaving remnants which persist as popliteal and peroneal arteries. Prior to sciatic regression the popliteal and peroneal arteries establish continuity with the superficial femoral artery (1,2). Persistent sciatic artery is a direct continuation of the internal iliac artery. It is a rare anatomic variant where the sciatic artery does not regress during fetal development (1). There are four types of PSA. In type 1 and type 2, the PSA is completely present. The distinction between types 1 and 2 is that in type 1 there is a fully developed superficial femoral artery (SFA) and in type 2 the SFA is partially or completely absent. Our case is an example of type 2 PSA.

The significance of recognizing persistent sciatic artery lies in its tendency to develop aneurysms and subsequent limb threatening thromboembolism, thus, early recognition may improve morbidity.