What does the subclavian vein drain from the arm?

Subclavian Vein Drainage in the Upper Extremity

The subclavian vein primarily drains blood from the upper extremity, receiving venous drainage from the axillary vein, which is the continuation of the basilic and brachial veins from the arm. 1

Venous Anatomy and Drainage Pattern

• The subclavian vein receives blood from the axillary vein, which is formed by the confluence of the basilic and brachial veins from the arm 1

• The axillary vein receives drainage from multiple tributaries including:

  • Basilic vein (main deep vein of the arm) 1
  • Brachial veins (accompanying the brachial artery) 1
  • Subscapular veins 2
  • Lateral thoracic veins 2
  • Superior thoracic veins 2

• The cephalic vein (a major superficial vein of the upper limb) typically joins the axillary vein just before it becomes the subclavian vein 2

• The venous drainage pattern in the upper extremity does not precisely mirror the arterial supply - there is significant anatomical variation 2

Clinical Significance of Subclavian Vein Anatomy

• The subclavian vein is a common site for central venous access due to its consistent anatomical location and direct path to the superior vena cava 3

• The right internal jugular vein is often preferred over the subclavian vein for central venous catheterization due to its more direct trajectory to the cavo-atrial junction and lower risk of complications 3

• The subclavian approach for central venous access carries higher risks of pneumothorax, catheter fatigue, and "pinch-off syndrome" due to compression between the clavicle and first rib 3

• When the subclavian vein becomes occluded, collateral venous pathways develop, primarily through veins in the neck region 4

• In cases of axillary vein occlusion, collateral flow is established mainly through chest wall venous pathways 4

Pathological Considerations

• Upper extremity deep vein thrombosis (UEDVT) can affect the subclavian vein and may present with arm swelling and pain 1

• Subclavian vein stenosis or occlusion can lead to venous hypertension in the arm, particularly in patients with arteriovenous fistulas for hemodialysis 5

• Subclavian steal syndrome occurs when proximal subclavian artery stenosis causes retrograde blood flow in the ipsilateral vertebral artery, potentially leading to posterior cerebral circulatory insufficiency 6

• Blood pressure asymmetry between arms (difference >10-15 mmHg) is a key diagnostic finding for subclavian artery stenosis, with the side with lower pressure indicating the affected side 6

Imaging Considerations

• Duplex ultrasonography is commonly used to evaluate the subclavian vein and can identify flow abnormalities or thrombosis 6

• CT angiography (CTA) and MR angiography (MRA) are highly accurate alternatives for evaluating the subclavian vessels with sensitivities of 96.2% and 95.4%, respectively 7

• When evaluating the proximal venous segments (superior vena cava, brachiocephalic vein, and subclavian vein), MDCT angiography has a stenosis detection accuracy of 98.4% 7