Basilic vein: the superficial vein on the little-finger side of the arm

What it is

The basilic vein is a large superficial vein on the medial side of the arm.

Location

It begins from the medial end of the dorsal venous network of the hand and runs up the medial forearm and arm. It pierces the deep fascia in the mid-arm and joins the brachial veins to form the axillary vein. The median cubital vein joins it to the cephalic vein.

Function

It drains the medial side of the hand and forearm.

Body system

Cardiovascular · paired (left and right)

FMA ID

FMA22910 (Foundational Model of Anatomy)

Key facts

• It is a common choice for venous access and for peripherally inserted central catheters (PICC lines).
• Its deep course in the upper arm makes it a common choice for an arteriovenous fistula for dialysis after superficialisation.

The basilic vein arises from the ulnar (little finger) side of the superficial venous network on the back of the hand. In the forearm it climbs along the back and medial side, then curves forwards to reach the front of the elbow, where it passes in front of the medial epicondyle of the humerus. (Radiopaedia: Basilic vein.)

TeachMeAnatomy groups it with the cephalic vein as one of the two main superficial veins of the upper limb. Both lie in the subcutaneous tissue and begin in the dorsal venous network of the hand. (TeachMeAnatomy: Venous Drainage of the Upper Limb.)

OpenStax summarises its course in one line: the basilic vein continues through the arm medially and superficially to the axillary vein. (OpenStax Anatomy and Physiology 2e, 20.5: Circulatory Pathways.)

Above the elbow the basilic vein continues up the anteromedial arm, medial to the brachial artery. About halfway between the elbow and the axilla it passes through the deep (brachial) fascia at an opening called the basilic hiatus, so its upper part is no longer just under the skin. (Radiopaedia: Basilic vein.)

At the lower border of teres major it unites with the paired brachial veins in the axilla, and the vessel formed is the axillary vein. (Radiopaedia: Basilic vein.)

The brachial veins are the deep veins of the arm. They form from the radial and ulnar veins in the cubital fossa and run up close to the brachial artery until they meet the basilic vein at teres major. (Radiopaedia: Brachial veins.)

Along the upper arm the basilic vein runs with the medial antebrachial cutaneous nerve (medial cutaneous nerve of the forearm). Surgeons must spare this nerve when they expose the vein. (Deguchi J, Sato O. Transposed Brachial–Basilic Arteriovenous Fistula for Vascular Access in Japan. Ann Vasc Dis. 2018.)

At its origin the brachial artery is accompanied by the basilic vein and the median nerve, all on the medial side of the humerus. (Radiopaedia: Brachial artery.)

The median cubital vein leaves the cephalic vein just below the lateral epicondyle, crosses the cubital fossa obliquely over the bicipital aponeurosis and ends in the basilic vein on the medial side. (TeachMeAnatomy: Median Cubital Vein.)

The median antebrachial vein, which runs up the front of the forearm, ends in the basilic vein or the median cubital vein. Sometimes it divides at the elbow into a median cephalic and a median basilic vein that drain into the cephalic and basilic veins respectively. Radiopaedia describes the superficial veins of the upper limb as highly variable. (Radiopaedia: Basilic vein.)

The pattern formed at the elbow is often described as H-shaped (a single median cubital vein) or M-shaped (median cephalic and median basilic veins). (Radiopaedia: Median cubital vein.)

The junction with the deep veins also varies. In a dissection study of 40 limbs, the two brachial veins most often joined the axillary vein separately; in 11 limbs one brachial vein joined the axillary vein and the other joined the basilic vein, and in 3 limbs both brachial veins ended in the basilic vein in the arm. (Lee H et al. The axillary vein and its tributaries are not in the mirror image of the axillary artery and its branches. PLoS One. 2019.)

Both veins start in the dorsal venous network of the hand. The basilic vein drains its ulnar side and runs up the medial side of the limb; the cephalic vein drains its radial side and runs up the lateral side. The median cubital vein links them at the elbow. (TeachMeAnatomy: Venous Drainage of the Upper Limb.)

Their endings differ. The cephalic vein stays superficial up to the shoulder, runs in the deltopectoral groove and pierces the clavipectoral fascia to join the first part of the axillary vein. The basilic vein goes deep in the middle of the arm and forms the axillary vein together with the brachial veins. (Radiopaedia: Cephalic vein.)

The axillary vein that the basilic vein helps to form climbs through the axilla on the medial side of the axillary artery and becomes the subclavian vein at the lateral border of the first rib. (Radiopaedia: Axillary vein.)

The lateral superficial vein, the deltopectoral groove and pacemaker access. Cephalic vein.

The basilic vein is a frequent site for taking blood, although the median cubital vein in front of the elbow is used more often. On ultrasound at the front of the elbow it lies on average about 1.2 cm (range 0.4 to 3.5 cm) medial to the brachial artery, and it becomes visible after a tourniquet is applied in about 65% of people. (Radiopaedia: Basilic vein.)

The median cubital vein, which joins the basilic vein at the elbow, is separated from the brachial artery and median nerve by the bicipital aponeurosis, one reason it is the usual first choice for blood tests. (TeachMeAnatomy: Median Cubital Vein.)

A peripherally inserted central catheter (PICC) is a long, thin tube passed through an arm vein until its tip lies in a large central vein near the heart. A review of PICC placement states that a patent, sizeable basilic vein is always preferred for the first attempt, because it is very superficial and easy to find in the medial arm. (Gupta N et al. Tunneled and routine peripherally inserted central catheters placement in adult and pediatric population: review, technical feasibility, and troubleshooting. Quant Imaging Med Surg. 2021.)

The same review advises puncturing the vein in the upper arm, as far down as possible but above the cubital fossa, because access in the cubital fossa causes discomfort after the procedure. (Gupta N et al. Tunneled and routine peripherally inserted central catheters placement in adult and pediatric population: review, technical feasibility, and troubleshooting. Quant Imaging Med Surg. 2021.)

The brachial vein is the second choice: it lies deeper, right beside the brachial artery and close to the median nerve, so arterial puncture and nerve injury are greater risks. The cephalic vein comes last, because it is often small, varies in its anatomy, turns at an acute angle near the axilla and has higher rates of thrombosis. (Gupta N et al. Tunneled and routine peripherally inserted central catheters placement in adult and pediatric population: review, technical feasibility, and troubleshooting. Quant Imaging Med Surg. 2021.)

For people on haemodialysis, a surgeon can join an artery to a vein (an arteriovenous fistula) so that the vein enlarges and can be needled repeatedly. The basilic vein in the upper arm is attractive for this because it has usually been spared repeated blood draws and intravenous cannulas. (Deguchi J, Sato O. Transposed Brachial–Basilic Arteriovenous Fistula for Vascular Access in Japan. Ann Vasc Dis. 2018.)

Because its upper part lies deep to the fascia, the vein must be moved closer to the skin to be usable, either by lifting it (elevation or superficialisation) or by tunnelling it to a new position (transposition). The operation can be done in one stage or two; trials report better maturation with the two-stage approach but a longer wait before the fistula can be used. (Deguchi J, Sato O. Transposed Brachial–Basilic Arteriovenous Fistula for Vascular Access in Japan. Ann Vasc Dis. 2018.)

In Japan the transposed brachial-basilic fistula is usually used after radial-cephalic and brachial-cephalic fistulas, as a third or later option. (Deguchi J, Sato O. Transposed Brachial–Basilic Arteriovenous Fistula for Vascular Access in Japan. Ann Vasc Dis. 2018.)

The nearest named structures in the 3D model, measured from the centre of each part:

• Anterior ulnar recurrent artery · cardiovascular
• Posterior ulnar recurrent artery · cardiovascular
• Common interosseous artery · cardiovascular
• Median cubital vein · cardiovascular
• Humeral head of pronator teres · muscular
• Recurrent interosseous artery · cardiovascular
• Cephalic vein · cardiovascular
• Anconeus · muscular
• Inferior ulnar collateral artery · cardiovascular
• Supinator · muscular