Bilateral variations in the roots of origin of the phrenic nerve and absence of fibrous pericardium in an old male cadaver

Abstract

Phrenic nerve provides the major motor supply to diaphragm. Various anatomical variations in the course and distribution of the phrenic nerve have reported before. Here we report a rare bilateral asymmetric variation in the roots of origin of the phrenic nerve and absence of fibrous pericardium in an old male cadaver. Specifically, the right phrenic nerve was arising from the upper trunk of the brachial plexus (C5) and the left side nerve originated from the supraclavicular nerve and a tiny branch from C5. In the same cadaver both sides phrenic nerve were buried in the mediastinal pleura. Another interesting finding was absence of the fibrous pericardium. To the best of our knowledge the presented case showed a very rare variation in the roots of origin of the phrenic nerve accompanied with pericardial anomaly which has been less reported. We think such case is of practical importance during supraclavicular block during anesthesia.