Variation in median nerve nutritional arteryat the distal end of forearm: case report

The median nerve is one of the most important branches of the brachial plexus. Due to the role of the median nerve in sensory and motor innervation of the forearm and hand in the upper limbs, its blood supply is very important. Awareness of variations in the blood supply pattern to this nerve reduces the incidence of necrosis and ischemia of the nerve during surgical and diagnostic procedures.

During routine dissection of the cadaver of a 65-year-old man fixed in formalin (10%), in the Department of Anatomy and Reproductive Biology, Shahid Beheshti University of Medical Sciences, a rare variation was observed in the median nerve nutritional artery at the distal end of the left forearm. After dissection of the skin, superficial and deep fascia, anterior compartment forearm muscles, nerves and blood vessels were exposed from surrounding tissues. The median nerve passed through the two heads of the pronator teres muscle and left the cubital fossa in the depth of the flexor digitorum superficialis and the surface of the flexor digitorum profundus in the forearm. It was observed that at the distal end of the left forearm between the flexor carpi radialis and the flexor digitorum superficialis, a relatively thick branch originates from the radial artery and supplies blood to the median nerve. This branch was separated from the radial artery (before the artery enters the anatomical snuffbox) and crossed the surface of the flexor carpi radialis muscle and inserted into the median nerve sheath. In the forearm, this branch was the only artery supplying blood to the median nerve.

Due to the superficial position of the median nerve at the distal end of the forearm, physical damage to the nerve and its nutritional artery leads to necrosis and ischemia of the nerve, and ultimately disturbed the transmission of sensory and motor messages.