Sonographic Findings of the Bifid Median Nerve and Persistent Median Artery in Carpal Tunnel: A Preliminary Study in Chinese Individuals

Abstract

OBJECTIVE:The aim of this study was to investigate the prevalence of anatomic variations of the bifid median nerve, persistent median artery and persistent median vein in Chinese individuals and their relationship with carpal tunnel syndrome.METHODS:One hundred and sixty median nerves were examined using ultrasonography and colour Doppler ultrasonography. The location, shape, and size of the bifid median nerve, persistent median artery and persistent median vein were recorded. The cross-sectional area of the bifid median nerve (two trunks) was measured at the level of the pisiform.RESULTS:Among the 160 wrists examined, a bifid median nerve was observed in 15 (9.4%) wrists, and a persistent median artery was observed in 12 (7.5%) wrists. These two variations either coexisted or were observed independently, and the probability of coexistence (6.3%) was higher than the probability of existing independently (bifid median nerve only 3.1%, persistent median artery only 1.3%). The cross-sectional area of the radial trunk was greater than (13 in 15, 86.7%) the cross-sectional area of the ulnaris trunk. Persistent median vein was observed in 9 wrists (5.6%).CONCLUSIONS:The persistent median artery and bifid median nerve tend to coexist, and the persistent median vein sometimes runs parallel to the persistent median artery. Their positional relationship in carpal tunnel is uncertain, and thus, preoperative ultrasound is necessary. These three variations do not present any additional risk for the development of carpal tunnel syndrome.

Persistent median artery inside the carpal tunnel: description and surgical implications

“…The topography of the PMA and MN along the forearm in the present case corroborates Chen et al and seems to be very constant. 12 Nevertheless, such topography changes in the carpal tunnel in a variable way: anterior, anterolateral or anteromedial position, which is similar to the present case. 10,12 Thus, this makes a preoperative ultrasound an essential tool to avoid iatrogenic injuries during the surgical procedure in the CTS.…”

“…While Pierre-Jerome et al described that the PMA was more frequent bilaterally, and when unilateral, it was more frequent in the left limb of females, 11 Chen et al reported that there is no statistical difference regarding the side of occurrence. 12 Furthermore, bilateralism was not verified in the present study.…”

Arteria mediana persistente: una variación anatómica vascular en el miembro superior. Estudio anatómico, revisión bibliográfica y estudio clínico en 128 pacientes

“…(9,10) La persistencia de la arteria mediana también puede ocurrir junto con anomalías del nervio mediano. Varios autores han descrito división del nervio mediano por la arteria mediana (11) mientras que otros han informado de la aparición de arteria mediana persistente asociada con una división alta del nervio, observándose una probabilidad más elevada de coexistencia de ambas anomalías (63%), que la probabilidad de presentarse independientemente. (12) Así ocurre en nuestro caso anatómico, en el que observamos un nervio mediano bífido dividido 5 cm.…”

The High Origin of the Radial Artery (Brachioradial Artery): Its Anatomical Variations, Clinical Significance, and Contribution to the Blood Supply of the Hand

“…Our present findings indicate that the prominent superficial palmar branch contributed to the formation of superficial palmar arch more often when the brachioradial artery occurred. The presence of atypical arterial patterns in the upper limb can be predicted based on the Color Doppler ultrasonography, which facilitate the assessment of the origin, course, variations, and locations of both arteries and accompanying veins [ 53 , 54 ].…”