CT Angiographic Evaluation of Congenital Anastomoses between Femoropopliteal Vein and Deep Femoral Vein: Types and Incidence.

Abstract

To evaluate congenital anastomotic channels between femoropopliteal veins and deep femoral veins with the use of computed tomographic (CT) venography. CT venography of 488 limbs in 244 patients (105 men; mean age, 61 y; age range, 18-96 y) performed between January 2016 and December 2016 was retrospectively evaluated. The presence or absence of anastomotic channels (> 3 mm in diameter) connecting a femoropopliteal vein to a deep femoral vein was determined, and the observed channels were classified based on their location and course. Two types of anastomotic channels were observed in 32 patients (13%): a persistent sciatic vein (PSV) in 24 limbs of 15 patients (6%) and a retrofemoral channel (RFC) in 22 limbs of 19 patients (8%). A PSV anastomosed with the popliteal vein in the popliteal fossa, coursed posterior to the adductor magnus muscle, and drained into the deep femoral vein. An RFC anastomosed with the femoral vein at the level of the adductor hiatus, coursed posterior to the femoral shaft, and drained into the deep femoral vein. PSVs and RFCs were of similar size or larger than adjacent femoropopliteal veins in 50% (12 of 24) and 22% of limbs (4 of 22), respectively. Anastomotic channels connecting a femoropopliteal vein to a deep femoral vein are not a rare variation and may have an important role in collateral venous drainage of the lower extremities.