Persistent Median Artery, Bifid Median Nerve, and Reversed Palmaris Longus Encountered During Cadaveric Dissection:...

The median artery is a transient embryological structure that normally disappears with the development of the radial and ulnar arteries. In rare instances, though, it persists as the persistent median artery (PMA). The superficial and deep palmar arches are formed through the anastomoses of the radial and ulnar arteries, giving hand and digits their main blood supply. This complex network of vessels and their anastomoses are prone to anatomical variations based on how the anastomosis occurs and which arteries contribute to this anastomosis. While it normally forms through the anastomosis of the radial and ulnar arteries, the superficial palmar arch (SPA) may also form differently, as in our case here, where the median artery persisted and branched off the radial artery, anastomosing with the ulnar artery to give rise to the SPA. This may also interfere with the normal compartmental architecture within the hand, possibly contributing to various clinical pathologies like carpal tunnel syndrome (CTS). Notably, in addition to the persistent median artery, our findings revealed a reversed palmaris longus and a bifid median nerve. These two additional variations can potentially exacerbate the risk of CTS. Alone, the coexistence of the PMA and the reversed palmaris longus is deemed a rare anomaly, only reported once in the literature. The addition of a third variation to the existing ones, like the bifid median nerve, is first reported by us and calls for more investigation for a possible genetic mutation. In this case, we report a persistent median artery, reversed palmaris longus muscle, and bifid median nerve in the forearm of a male cadaver found during a routine anatomy teaching session.