Which vein is visible in the lower leg?

Visible Veins in the Lower Leg

The great saphenous vein is the most commonly visible vein in the lower leg, running superficially from the medial malleolus of the ankle up the medial aspect of the leg. 1, 2

Anatomy of Lower Leg Veins

The lower leg contains several veins that may be visible through the skin:

1. Great Saphenous Vein (GSV)

   • Longest vein in the body
   • Originates from the dorsum of the foot at the medial malleolus
   • Ascends along the medial aspect of the leg
   • Continues to the level of the groin skin crease 3
   • Often visible at the ankle and medial calf

2. Small Saphenous Vein

   • Runs along the posterior aspect of the leg
   • Typically terminates in the popliteal vein behind the knee 4
   • May be visible in the posterior calf

3. Accessory Saphenous Veins

   • Lateral accessory branch of GSV (found in approximately 37.5% of people)
   • Medial accessory branch of GSV (found in approximately 8.5% of people) 4

Anatomical Considerations

The visibility of veins in the lower leg depends on several factors:

• Fascial Compartments: The great saphenous vein runs in a fascial canal derived from the deep fascia in 85% of cases. This fascial sheath is absent in the lowermost quarter of the leg, making the vein more visible in this region 5

• Depth: The proximal portions of the GSV are less visible as they are "concealed" (which is the actual meaning of "saphenous" from Arabic "el safin") 6

• Diameter: The diameter of the GSV varies along its course, with significant dilation occurring in the lower thigh region when venous reflux is present (average 4.7mm with reflux vs 4.2mm without) 7

Clinical Significance

Understanding the visible veins in the lower leg is important for:

1. Diagnosis of venous conditions:

   • Duplex ultrasound is the gold standard for evaluating venous reflux 2
   • Visible varicosities may indicate underlying venous insufficiency

2. Ultrasound evaluation:

   • When performing compression ultrasound for DVT, the common femoral, superficial femoral, and popliteal veins are the primary focus 1
   • Complete duplex ultrasound (CDUS) is the preferred test for diagnosing DVT, which includes compression of deep veins from the inguinal ligament to the ankle 1

3. Anatomical variations:

   • Duplication of the GSV occurs in approximately 1% of cases and can be clinically significant 3
   • Variations in termination patterns and accessory branches may affect diagnostic and therapeutic procedures 4

Common Pitfalls

• Terminology confusion: The superficial femoral vein is actually part of the deep venous system, not the superficial system as the name suggests 1

• Incomplete evaluation: Limited protocols that don't include calf veins require a second study in 5-7 days to safely exclude DVT 1

• Misidentification: Accessory saphenous veins may be mistaken for duplicated GSVs 3

• Overlooking iliac or inferior vena cava obstruction: These conditions may cause lower extremity pain or swelling but require different evaluation techniques 1

By understanding the normal anatomy and variations of visible veins in the lower leg, clinicians can better diagnose venous conditions and plan appropriate interventions when necessary.