The majority of clinically relevant venous refluxes of the superficial veins requiring invasive treatment occur in the great saphenous vein (GSV) territory. The GSV runs from the inner part of the ankle, along the medial aspect of the leg, to the groin, where it drains into the common femoral vein (CFV) through the saphenofemoral junction (SFJ). Next to the SFJ, a bundle of tributaries coming from the pelvis and abdominal wall (the superficial epigastric vein and the external pudendal vein), lateral aspect of the hip (the superficial circumflex iliac vein), and the anterior (the anterior accessory saphenous vein) and posteromedial aspect of the thigh (the posterior accessory saphenous vein) drain into the GSV [1, 2]. The GSV, similarly to other veins, is equipped with valves that preclude venous reflux, i.e. a backward flow. In the area of the SFJ two valves are especially important: the terminal valve, which is located next to the junction with the femoral vein, at a mean distance of 0.4 cm from the junction, and the preterminal valve, which is located more distally from the SFJ, usually at a distance of several centimetres from the femoral vein and distally from the above-mentioned tributaries (Fig. 1) [3, 4]. It should also be emphasised that the anatomy of the SFJ is not constant and because of this high anatomical and functional variability there are many options of the flow and reflux in this area.
The first classification of these variabilities of the SFJ, which was based on venographic findings, was proposed by Hach [5]. Contrary to the venographic examination, duplex sonography is capable of independent assessment of the function of the terminal and preterminal valves. Based on such separate evaluations of these valves, Stücker et al. presented a new classification of venous flow abnormalities in the area of the SFJ [6]. This classification is summarised in Table 1. In addition to Stücker’s types 1-3, we propose a new type 4: in which the reflux originates in a tributary and enters the anterior accessory saphenous vein with both terminal and preterminal valves being competent.
Sonographic technique
Firstly, sonographic assessment of the area of the SFJ should exclude thrombosis of the femoral vein and the GSV, primarily using a compression test (the veins should be easily compressible with the sonographic probe). Then, venous anatomy of the region should be evaluated and several questions should be answered:
• are all veins visible?,
• is the SFJ at a typical location?,
• which tributaries are visible? (Fig. 1),
• are the valves of the GSV visible, and are their leaflets capable of moving during the blood flow (after thrombosis or severe inflammatory processes these leaflets may become thickened and immobile)? (Figs. 2, 3),
• is the GSV dilated? (Fig. 4),
• are there any pathological structures in the area of the SFJ, such as: enlarged lymph nodes, haematomas, etc.?
Assessment of venous flow in the area of the SFJ should preferentially be performed in the standing position [7, 8]. Some manoeuvres can be done in order to enhance the flow and to facilitate the investigation. In a standing patient a manual compression of the calf, or dynamic manoeuvres like forefoot elevation manoeuvre (the so-called Wunstorf’s manoeuvre), are the most useful ones [9]. These manoeuvres elicit flow towards the heart in the veins during the so-called muscular systole, which is either artificially caused by the examiner through manual compression, or is evoked by contraction of patient’s muscles during Wunstorf’s manoeuvre or other similar manoeuvres. Following relaxation of muscle pump the muscular diastole begins. Competent veins present with an upward flow during muscular systole, which – during muscular diastole – is followed by a short period of backward flow, until the leaflets of the valves become closed. In a case of incompetent valves of the SFJ an upward flow during muscular systole and backward flow during diastole will be found, with duration of such a backward flow longer than one second. A permanent flow in the SFJ toward femoral vein, especially if such a flow is of high velocity and does not respond to the reflux-provoking manoeuvres, suggests an occlusion (usually post-thrombotic) of the deep veins with the flow bypassing an obstacle through the GSV (Fig. 5).
Flow characteristics in the area of SFJ: in the CFV, and the GSV and its tributaries can either be assessed using colour Doppler mode (Fig. 6A, B), or pulsed wave mode (Fig. 6C and 10). While colour Doppler gives a better impression of the overall haemodynamic pattern, and pulsed wave mode allows the quantitative assessment of flow, especially duration of reflux, which is important to evaluate borderline cases. In the area of the SFJ we define reflux as pathological if backward flow after the above-mentioned manoeuvres is longer than one second (Fig. 10) [8]. Of note, using the above-mentioned reflux-provoking manoeuvres, for the assessment of competence of the terminal valve the Doppler gate should be positioned in the common femoral vein next to the SFJ, while for the assessment of preterminal valve this gate should be positioned between the terminal and preterminal valves.
Since venous anatomy in this area is highly variable, we suggest placing the sonographic probe transversely to the axis of the extremity. In this way it is easier to assess the anatomy. Nevertheless, in order to enable registration of venous flow with the probe placed transversely, it should not be positioned perpendicularly to the skin but rather slightly tilted, as shown in Fig. 7. Flow characteristics should be assessed in the CFV, and the SFJ and tributaries using colour Doppler mode (Figs. 5–10; Table 1). Sometimes, for better documentation of reflux in the tributaries, the probe should be positioned longitudinally.
Nowadays lots of treatment options are available. We can tailor treatment to the findings and dilatation of veins. Competence of the terminal valve with incompetent preterminal valve may lead to the choice of one or another tactical approach. It is important to have an exact documentation of the findings to allow trouble-shooting in the follow up if new refluxes appear. The exact preoperative documentation of the situation in the SFJ is of uttermost importance when driving surveys to compare different surgical treatment techniques.
We would like to thank Dr. Christine Zollmann for her contribution concerning the Stücker’s type 4.
We would also like to thank Dr. Marian Simka for his worthy input during the editing process.
The authors declare no conflict of interest.
References
1. Caggiati A., Bergan J.J., Gloviczki P., Jantet G., Wendell-Smith C.P., Partsch H. Nomenclature of the veins of the lower limbs: an international interdisciplinary consensus statement. J Vasc Surg 2002; 36: 416-422.
2. Cavezzi A., Labropoulos N., Partsch H., Ricci S., Caggiati A., Myers K., Nicolaides A., Smith P.C. Duplex ultrasound investigation of the veins in chronic venous disease of the lower limbs – UIP consensus document. Part II. Anatomy. Eur J Vasc Endovasc Surg 2006; 31: 288-299.
3. Dickson R., Hill G., Thomson I.A., van Rij A.M. The valves and tributary veins of the saphenofemoral junction: ultrasound findings in normal limbs Veins Lymphatics 2013; 2: e18.
4. Mühlberger D., Morandini L., Brenner E. Venous valves and major superficial tributary veins near the saphenofemoral junction. J Vasc Surg 2009; 49: 1562-1569.
5. Hach W., Hach-Wunderle V. Die Rezirkulationskreise der primären Varikose – Pathophysiologische Grundlagen zur chirurgischen Therapie. Springer Verlag, Berlin 1994.
6. Stücker M., Moritz R., Altmeyer P., Reich-Schupke S. New concept: different types of insufficiency of the saphenofemoral junction identified by duplex as a chance for a more differentiated therapy of the great saphenous vein. Phlebology 2013; 28: 268-274.
7. Coleridge-Smith P., Labropoulos N., Partsch H., Myers K., Nicolaides A., Cavezzi A. Duplex ultrasound investigation of the veins in chronic venous disease of the lower limbs – UIP consensus document. Part I. Basic principles. Eur J Vasc Endovasc Surg 2006; 31: 83-92.
8. De Maeseneer M., Pichot O., Cavezzi A., Earnshaw J., van Rij A., Lurie F., Smith P.C. Duplex ultrasound investigation of the veins of the lower limbs after treatment for varicose veins – UIP consensus document. Eur J Vasc Endovasc Surg 2011; 42: 89-102.
9. Mendoza E. Provocation maneuvers for the duplex ultrasound diagnostic of varicose veins. Phlebologie 2013; 42: 357-362.
10. Mendoza E., Morrison N., Lattimer C. Examination of the great saphenous vein. In: Mendoza E., Lattimer C., Morrison N. Duplex ultrasound of superficial leg veins. Springer Berlin Heidelberg 2014; 119-170.
11. Mendoza E. The saphenofemoral junction in ultrasound. Phlebologie 2014; 43: 42-44.
