The median cubital vein lies superficially to the brachial artery in the region of the cubital fossa.
In more detail, the relationship is as follows:
The median cubital vein is a superficial vein located in the subcutaneous tissue of the cubital fossa (the bend of the elbow). It connects the basilic and cephalic veins. Crucially, it passes anterior (in front of) the brachial artery. Therefore, when considering the "top" in the sense of superficial anatomical layers, the median cubital vein occupies that position relative to the brachial artery.
Other structures in the vicinity include the medial and lateral cutaneous nerves of the forearm, which are associated with the basilic and cephalic veins, respectively. These structures are all important to consider during procedures like venipuncture.
