Median Nerve Entrapment by Superficial Brachioulnar Artery: Anatomical Insights and Clinical Perspective.

Entrapment neuropathy of the median nerve is typically caused by compression at specific anatomical points. However, idiopathic cases, where the standard anatomical compression points are normal, pose diagnostic challenges. This report highlights a unique case discovered during an anatomical dissection of the right upper limb in a 62-year-old male cadaver, where the median nerve was compressed by an unusual branch of the brachial artery, termed the superficial brachioulnar artery (SBUA). The median nerve formed at the distal half of the arm, receiving additional components from the lateral cord, with a noted communication with the musculocutaneous nerve. The SBUA, originating from the brachial artery, passed between the roots of the median nerve and continued superficially, forming the superficial palmar arch. The coexistence of neurovascular variations is clinically significant as it may lead to nerve compression and subsequent symptoms. This case is the first documented instance of median nerve compression by an SBUA. Such variations are crucial for surgical and diagnostic procedures, as abnormal vascular structures can be mistaken for veins, leading to iatrogenic injuries. In addition, understanding these variations helps explain idiopathic median nerve neuropathies and highlights the need for thorough anatomical knowledge to prevent complications during surgical interventions.