Near the popliteal artery the popliteal vein follows and carries blood from the knee to the thigh and calf muscles to the heart. The junction of the anterior tibial vein and posterior tibial vein defines where the origin of the popliteal vein will occur. The popliteal artery, located behind the knee, is where the popliteal vein begins to extend. The popliteal vein drains the peroneal vein before it reaches the knee joint, where it becomes the femoral vein. This change occurs as the popliteal vein leaves the adductor canal, which is also known as Hunter's canal. The popliteal vein is part of the cardiovascular system, resulting from the merging of the tibial veins in the leg. Dangers of the popliteal vein include aneurysm, which have a high risk of pulmonary embolism and death if left without treatment. This treatment of the popliteal vein aneurysm is usually undertaken with surgery. The popliteal vein may or may not be symptomatic in cases of an aneurysm, but will be operated on in either case.