Median Basilic Vein and Median Cephalic Vein: a Rare Variant

Introduction

Median cubital vein is a large communicating vein which shunts blood from cephalic vein to basilic vein. It begins from the cephalic vein 2.5 cm below the bend of the elbow, runs obliquely upward and medially and ends in the basilic vein, 2.5 cm above the medial epicondyle. It is separated from the brachial artery by the bicipital aponeurosis.

It receives tributaries from the front portion of the forearm (median vein of the forearm) and is connected to the deep veins through a perforator vein which pierces the bicipital aponeurosis. The perforator vein fixes the median cubital vein and thus makes it ideal for intravenous injections.

Median vein of the forearm/median antebrachial vein begins from the palmar venous network and ends in the basilic/cephalic vein in front of the elbow. In some cases, it divides into median cephalic and median basilic veins which join the cephalic and basilic vein respectively; this pattern replaces the median cubital vein^1-6.

Embryologically, development of blood and blood vessels starts as early as 15-16 days in the mesoderm of the yolk sac, chorion, and body stalk. Blood vessels develop from isolated masses and cords of mesenchyme in the mesoderm called blood islands. Growth and fusion of blood islands form an extensive network of blood vessels throughout the embryo⁷.

Methods

The variation was observed during routine dissection on the right upper limb of a male cadaver. After careful removal of the skin and superficial fascia of the cubital fossa, the structures were identified.

Results

In most of the population, the cephalic vein drains into the basilic vein through median cubital vein (70-80%).⁸ But in this case we noted absence of median cubital vein, and presence of median cephalic and median basilic veins arising from the median vein of forearm and draining into cephalic and basilic veins, respectively.

Discussion and conclusion

Superficial veins of the upper limb are of importance in medical practice because these are most commonly opted for intravenous injections, cardiac catheterization, access for dialysis, health screening and withdrawing blood for transfusion or for testing. The median cubital vein is the vein of choice, because of the fact that it is fixed and does not slip away during piercing. Therefore, it is important to know about the anatomic variations of this vein in the population. The cause of such variations might be because of the varied blood islands formation in embryological life.

Meta-analysis of studies on superficial veins of cubital fossa by Kaissar Yammine et al.⁹ showed different possibilities of variations such as M shaped arrangement in 44-60% (type 1), N shaped arrangement in 20-25% (type 2), I/O shaped arrangement predominantly in females (type 3), type 4, type 5, type 6, type 7, and type 8.

In our case the median cubital vein was absent, and median vein of forearm gave rise to 2 tributaries, median cephalic and median basilic vein, which drained into cephalic and basilic vein, respectively (Type 1/ M shaped).

When the median cubital vein is absent, the basilic vein or the median basilic vein is preferred because of its better efficiency to become deep at the middle of the arm. The knowledge of anatomical variations is important in both clinical and surgical interventions.

Conflict of interests

The authors declare no conflict of interests.