Superficial veins

The superficial veins of the upper limb are a network of subcutaneous veins located in the skin and superficial fascia. These veins are important for thermoregulation and are commonly used for venipuncture, intravenous access, and blood sampling. The primary superficial veins of the upper limb are the cephalic vein, basilic vein, and the median cubital vein. These veins communicate extensively with the deep venous system through perforating veins and venous plexuses.

Main Veins

Cephalic Vein

• Begins on the dorsum of the hand from the lateral part of the dorsal venous network.
• Ascends along the lateral border of the forearm and arm, passing superficial to the biceps brachii.
• Travels through the deltopectoral groove between the deltoid and pectoralis major muscles.
• Pierces the clavipectoral fascia to drain into the axillary vein near the shoulder.

Basilic Vein

• Arises from the medial side of the dorsal venous network of the hand.
• Ascends along the medial side of the forearm and arm, superficial to the flexor muscles.
• At the middle of the arm, it pierces the brachial fascia to join the paired brachial veins and form the axillary vein.

Median Cubital Vein

• A superficial anastomotic vein that connects the cephalic and basilic veins in the cubital fossa.
• It lies over the bicipital aponeurosis and is a common site for venipuncture due to its visibility and accessibility.
• Its pattern may vary widely; sometimes it is absent or replaced by other oblique or transverse veins.

Accessory Veins

• Median vein of the forearm: Runs in the midline of the forearm and may drain into either the basilic or median cubital vein.
• Accessory cephalic vein: May arise on the dorsum of the forearm and join the cephalic vein above the wrist or mid-forearm.

Function

• Venous return: Drains deoxygenated blood from the superficial tissues of the hand, forearm, and arm into the deep venous system.
• Thermoregulation: Facilitates heat exchange through vasodilation and constriction in response to temperature changes.
• Venous access: Provides easy access points for IV medications, fluids, and blood withdrawal.

Physiological Role(s)

• Supports regulation of blood volume under varying physiological conditions.
• Acts as a reservoir for blood storage, especially during sympathetic activation.
• Allows compensatory rerouting of venous blood in case of deep vein obstruction.

Relations

• Cephalic vein: Travels along the lateral margin of the biceps brachii and lies within the deltopectoral groove in the upper arm.
• Basilic vein: Lies medial to the biceps and is superficial in the lower arm but becomes deep proximally.
• Median cubital vein: Crosses superficially to the bicipital aponeurosis and is anterior to the brachial artery and median nerve (which are deeper).

Development

The superficial venous system develops from venous plexuses in the embryonic limb bud. The dorsal venous network gives rise to both the cephalic and basilic veins, which are preserved and become the dominant superficial drainage channels in the postnatal upper limb. Anastomotic veins such as the median cubital vein form from remodeling of superficial plexuses during late fetal development and early infancy.

Clinical Significance

• Venipuncture: The median cubital vein is the most frequently accessed site for drawing blood or inserting IV cannulas due to its size and fixed position.
• Thrombophlebitis: Superficial vein inflammation, often in IV lines, can involve cephalic or basilic veins, causing localized pain and swelling.
• Vein grafting: The cephalic vein is sometimes harvested for use in vascular or coronary artery bypass grafting procedures.
• Cannulation complications: Misplacement of IV cannulas can injure deeper structures such as the brachial artery or median nerve, especially if anatomy is variant.
• Venous mapping: Used before hemodialysis access creation to assess cephalic or basilic vein patency and size.

Imaging

• Ultrasound: The preferred noninvasive tool for visualizing superficial veins, especially during vascular access planning or in thrombosis evaluation.
• Venography: Invasive imaging that may be used in surgical planning or evaluation of vein occlusion or varicosities.

Anatomical Variations

• The median cubital vein may be absent, doubled, or replaced by an “M-shaped” venous pattern involving the median antebrachial vein.
• Accessory cephalic or basilic veins may alter drainage patterns in the forearm and arm.
• The basilic vein may pierce the fascia higher or lower than usual, affecting its accessibility during procedures.