Anatomy of the veno-muscular pumps of the lower limb.

OBJECTIVE: To study the anatomy of the veno-muscular pumps of the lower limb, particularly the calf pump, the most powerful of the lower limb, and to confirm its crucial importance in venous return. METHODS: In all, 400 cadaveric limbs were injected with green Neoprene latex followed by an anatomical dissection. RESULTS: The foot pump is the starter of the venous return. The calf pump can be divided into two anatomical parts: the leg pump located in the veins of the soleus muscle and the popliteal pump ending in the popliteal vein with the unique above-knee collector of the medial gastrocnemial veins. At the leg level, the lateral veins of the soleus are the bigger ones. They drain vertically into the fibular veins. The medial veins of the soleus, smaller, join the posterior tibial veins horizontally. At the popliteal level, medial gastrocnemial veins are the largest veins, which end uniquely as a large collector into the popliteal vein above the knee joint. This explains the power of the gastrocnemial pump: during walking, the high speed of the blood ejection during each muscular systole acts like a nozzle creating a powerful jet into the popliteal vein. This also explains the aspiration (Venturi) effect on the deep veins below. Finally, the thigh pump of the semimembranosus muscles pushes the blood of the deep femoral vein together with the quadriceps veins into the common femoral vein. CONCLUSION: The veno-muscular pumps of the lower limb create a chain of events by their successive activation during walking. They play the role of a peripheral heart, which combined with venous valves serve to avoid gravitational reflux during muscular diastole. A stiffness of the ankle or/and the dispersion of the collectors inside the gastrocnemius could impair this powerful pump and so worsen venous return, causing development of severe chronic venous insufficiency.

Anatomy and embryology of the small saphenous vein: nerve relationships and implications for treatment.

The aim of this paper is to describe the anatomical relations of the small saphenous vein (SSV) in order to define the high-risk zones for the treatment of chronic venous disease. The SSV runs in the saphenous compartment demarcated by two fascia layers: a muscular fascia and a membranous layer of subcutaneous tissue. The clinician should be keenly aware of the anatomical pitfalls related to the close proximity of nerves to the SSV in order to avoid their injury: At the ankle, the origin of the SSV is often plexiform, located deep below the fascia, and the nerve is really stuck to the vein. The apex of the calf is an area of high risk due to the confluence of nerves which perforate the aponeurosis. Moreover, the possible existence of a 'short saphenous artery' which poses a high risk for injection of a sclerosing agent due to a highly variable disposition of this artery surrounding the SSV trunk. For this reason, procedures under echo guidance in this area are mandatory. The popliteal fossa is probably a higher risk zone due to the vicinity of the nerves: the small saphenous arch is close to the tibial nerve, or sometimes the nerve of the medial head of the gastrocnemius muscle. In conclusion, before foam injection or surgery, a triple mapping of the small saphenous territory is mandatory: venous haemodynamical mapping verifying the anatomy that is highly variable, nerve mapping to avoid trauma of the nerves and arterial mapping. This anatomical study will help to define the main high-risk zones.

Anatomical variations of the femoral vein.

BACKGROUND: The venous anatomy is highly variable. This is due to possible venous malformations (minor truncular forms) occurring during the late development of the embryo that produce several anatomical variations in the number and caliber of the main venous femoral trunks at the thigh level. Our aim was to study the prevalence of the different anatomical variations of the femoral vein at the thigh level. METHODS: This study used 336 limbs of 118 fresh, nonembalmed cadavers. The technique included washing of the whole venous system, latex injection, anatomical dissection, and then painting of the veins. RESULTS: The modal anatomy of the femoral vein was found in 308 of 336 limbs (88%). Truncular malformations were found in 28 of 336 limbs (12%); unitruncular configurations in 3% (axo femoral trunk [1%] and deep femoral trunk [2%]). Bitruncular configurations were found in 9% (bifidity of the femoral vein [2%], femoral vein with axio-femoral trunk [5%], and femoral vein with deep femoral trunk [2%]). CONCLUSION: Truncular venous malformations of the femoral vein are not rare (12%). Their knowledge is important for the investigation of the venous network, particularly the venous mapping of patients with cardiovascular disease. It is also important to recognize a bitruncular configuration to avoid potential errors for the diagnosis of deep venous thrombosis of the femoral vein, in the case of an occluded duplicated trunk.