Page 176 - Libro vascular I

Chap-12.qxd 29~8~04 14:52 Page 167
ANATOMY OF THE LOWER LIMB VENOUS SYSTEM AND ASSESSMENT OF VENOUS INSUFFICIENCY
is not usually possible to identify all of these tribu- taries by ultrasound. The anterolateral thigh vein, sometimes called the anterior accessory saphenous vein, drains flow from the lateral aspect of the knee and runs obliquely across the anterior aspect of the thigh into the saphenofemoral junction (Fig. 12.5). However, it can sometimes join the LSV at a vari- able level below the junction. The anterolateral thigh vein is usually easy to identify with ultra- sound (see Fig. 12.20B). The posteromedial thigh vein drains flow from the posteromedial and poste- rior regions of the lower thigh and usually joins the main trunk of the LSV in the upper thigh. There are sometimes connections between the proximal SSV (or its branches) and the posteromedial vein in the lower thigh, or upper calf.
The distal SSV arises behind the outer aspect of the ankle (lateral malleolus) and runs superficially up the posterior calf in the saphenous compart- ment (see Fig. 12.2B). There are usually a number of perforating veins associated with the SSV, espe- cially from the gastrocnemius veins in the mid-calf. The SSV perforates the muscular fascia in the upper calf and passes between the heads of the gas- trocnemius muscle. It drains to the popliteal vein via the saphenopopliteal junction at the popliteal fossa, superior to the origin of the gastrocnemius vein. Approximately 60% of all SSVs join the popliteal vein in the popliteal fossa within 8 cm of the knee joint (Browse et al 1999). However, the anatomy of the SSV can be extremely variable, and the saphenopopliteal junction may be found well above the popliteal fossa, draining to the above- knee popliteal vein or superficial femoral vein. Alternatively, the SSV can arise directly from the gastrocnemius vein or share a common origin (Fig. 12.6). In addition, some people have a vein that runs as a continuation of the SSV, along the poste- rior thigh above the saphenopopliteal junction, as shown in Figure 12.6. This vein is called the Giacomini vein, but it is not commonly referred to in surgical text books (Georgiev et al 2003). It is also sometimes referred to as the proximal thigh extension of the SSV. The termination of the Giacomini vein is variable, and it may drain to the LSV in the thigh or groin via a posteromedial thigh vein. It can course up the back of the thigh and drain directly to the femoral vein or branches of the internal iliac vein system, such as the inferior
Common
femoral vein 6
Saphenofemoral
vein 5
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gluteal vein (Fig. 12.6). There is sometimes con- fusion as to whether a posterior thigh vein is the Giacomini vein or merely a posteromedial branch of the LSV. Generally, the Giacomini vein appears to remain in a superficial fascia compartment (similar to the LSV and SSV) in the lower thigh, whereas posteromedial branches of the LSV tend to lie above the saphenous fascia. Finally, there are
Long saphenous vein
Popliteal vein
Short saphenous vein
The SSV normally drains to the popliteal vein in the popliteal fossa at the saphenopopliteal junction
(position 1). It can arise from the gastrocnemius vein (GV) (position 2). It sometimes has a high origin from
the popliteal vein (position 3). The Giacomini vein, when present, runs above the level of the saphenopopliteal junction and has a variable origin. It may drain to the LSV, femoral vein or branches of the internal iliac vein (positions 4, 5 and 6). Note it is possible to confuse the posteromedial branch of the LSV with the Giacomini vein; see text.
4
Giacomini vein
3
1
2
Gastrocnemius vein
The level of the SSV origin can be highly variable, and potential positions are shown by numbers.
Figure 12.6