ORIGINAL COMMUNICATION Persistent Median Artery Cadaveric Study and Review of the Literature N. EID, Y. ITO, M.A. SHIBATA, AND Y. OTSUKI * Department of Anatomy and Cell Biology, Division of Life Sciences, Osaka Medical College, Takatsuki, Osaka, Japan The persistent median artery (PMA) may compress the median nerve (MN) and may be a significant supply of blood to the hand. Two cases of unilateral PMA (4%) were detected during the dissection of 50 upper limbs. The first case was a 75-year-old, right-handed male who suffered from chronic pain in both upper limbs, especially the left side. A dissection of his left upper limb revealed a PMA piercing both the MN and the medial branch of the anterior in- terosseous nerve. This artery coursed distally, deep to the transverse carpal ligament (TCL), forming a median-ulnar pattern for the superficial palmar arch (SPA). The PMA was superficial to two nerves at the distal edge of the TCL; the extraligamentous recurrent thenar (RT) branch of the MN and the third common digital nerve (TCDN). The second case was from the left side of an 80-year-old female found to have a high origin of the radial artery with trifur- cation of the latter into PMA, common interosseous, and ulnar arteries. The PMA passed deep to the TCL forming a radial-median-ulnar pattern of SPA. Both the transligamentous RT branch of the MN and the TCDN passed deep to the PMA inside the carpal tunnel, before the abnormal crossing of the latter nerve ventral to the SPA on its way to the digits. The relationships of the PMA to various MN branches may have important implications regarding the diag- nosis and treatment of MN compressive neuropathies. Clin. Anat. 24:627–633, 2011. V V C 2011 Wiley-Liss, Inc. Key words: persistent median artery; median nerve, carpal tunnel; palmar arch; Gantzer’s muscle; kentai INTRODUCTION Entrapment or compressive neuropathies are wide- spread clinical problems caused by compression of a nerve when it passes through fibro-osseous or muscular tunnels or deep to aponeurotic and vascu- lar channels such as a persistent median artery (PMA), especially in patients with various occupa- tions or with certain diseases (Spinner et al., 1991; Dellon, 2004; Lee and LaStayo, 2004; Eid and Otsuki, 2009). The median artery is usually only a transitory vessel that represents the arterial axis of the fore- arm during early embryonic life, providing the main blood supply to the hand in the embryo. After the 8th week of gestation, the ulnar and radial arteries develop, and the median artery usually regresses by undergoing apoptosis to become a small vessel accompanying the MN, the arteria comitans nervi mediani (Henneberg and George, 1992; Higgins and James, 2010). The median artery may persist in adult life in two different patterns, palmar and ante- brachial. The antebrachial type, which represents a partial regression of the embryonic artery is slender, short, and terminates before reaching the wrist. The palmar type, which represents the embryonic *Correspondence to: Y. Otsuki, Department of Anatomy and Cell Biology, Division of Life Sciences, Osaka Medical College, 2-7 Dai- gaku-Machi, Takatsuki, Osaka 569-8686, Japan. E-mail: an1001@art.osaka-med.ac.jp Received 24 October 2010; Revised 1 December 2010; Accepted 7 December 2010 Published online 12 January 2011 in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ca.21127 V V C 2011 Wiley-Liss, Inc. Clinical Anatomy 24:627–633 (2011)