Near the popliteal artery the popliteal vein follows and carries blood from the knee (as well as the thigh and calf muscles) back to the heart.
The junction of the anterior tibial vein and posterior tibial vein, near the knee, defines where the popliteal originates. 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, an open space inside the thigh that is also known as Hunter's canal.
One dangerous complication involving the popliteal vein is aneurysm. This abnormal bulging of the vessel’s walls results in a high risk of pulmonary embolism — a blood clot in the arteries of the lung — and death if left without treatment. Surgery is usually used to treat these aneurysms. Aneurysm in the popliteal vein may or may not cause symptoms, but will be operated on in either case.