Median artery of the forearm in human fetuses in northeastern Brazil: anatomical study and review of the literature

Abstract

A persistent median artery is a rare anomaly. It accompanies the median nerve along its course in the forearm and is of variable origin. It is associated with other local anatomical variations and may contribute significantly towards formation of the superficial palmar arch. In embryos, it is responsible mainly for the blood supply to the hand. The objective of this study was to research the frequency, type (forearm or palmar) and origin of the median artery in fetuses, correlating its presence with sex and body side. Red-colored latex was injected into 32 brachial arteries of human fetuses until its arrival in the hand could be seen. Twenty-four hours after the injection, the median arteries were dissected without the aid of optical instruments. Among the 32 forearms dissected, the median artery was present in 81.25 % (26) of the cases, and it was found more frequently in females and on the left side. Regarding origin, most of the median arteries originated in the common interosseous artery (38.5 %) and anterior interosseous artery (34.6 %). The mean length of the median arteries was 21.1 mm for the palmar type and 19.8 mm for the forearm type. The median artery has a high rate of persistence. It is important to be aware of this anatomical variation, since its presence may give rise to difficulties during routine surgical procedures on the wrist. Its presence may cause serious functional complications in the carpal tunnel, anterior interosseous nerve, round pronator syndromes, and ischemia of the hand.

Recently increased prevalence of the human median artery of the forearm: A microevolutionary change

“…Set 2 included the prevalences of persistent median arteries of the forearms presented in set 1, after excluding those obtained from foetuses (Aragão et al, 2017), and from studies that were limited only to hands (Tandler, 1896;Jaschtschinski, 1897;Barbosa Sueiro, 1916;Smanio, 1941;Weathersby, 1954;Coleman & Anson 1961;Kenesi et al, 1967;Chalmers, 1978;Braun et al, 1979;Ebner & Hammer 1988;Jelicic 1988;Olave et al, 1997;Gellman et al, 2001;Fazan et al, 2004;Barbe et al, 2005;Loukas et al, 2005;Bilge et al, 2006;Agarwal et al, 2014;Joshi et al, 2014; i.e. the palmar phenotype).…”

“…The median artery of the human forearm has been described as a foetal vessel that supplies the hand and regresses with the development of the radial and ulnar arteries (Jones and Ming, 1988). The regression of the median artery commences at approximately the eighth week of intrauterine life (Aragão et al, 2017). However, the median artery persists in a considerable number of foetuses of gestation ages 13-38 weeks (Aragão et al, 2017), in newborns and infants (Kopuz et al, 1995;George and Henneberg 1996) and in adults George, 1992a, 1992b;Rodriguez-Baeza et al, 1995;Kopuz and Gulman 1997;Rodriguez-Niedenfuhr et al, 1999;Lindley and Kleinert, 2003;D'Costa et al, 2006;Claassen et al, 2008;Natsis et al, 2009;Nayak et al, 2010;Eid et al, 2011).…”

“…They supply the forearm and the hand, or the forearm only, respectively. Commencement of the persistent median arteries occurs variably from the common interosseous artery, the anterior interosseous artery, the caudal angle between the common interosseous and ulnar arteries, and the ulnar artery (Rodriguez-Niedenfuhr et al, 1999;Claassen et al, 2008;Aragão et al, 2017;Cheruiyot et al, 2017). The median artery lies alongside the median nerve on its medial or lateral side (Cheruiyot et al, 2017) in the proximal third of the forearm, and in the distal part it is located between the anterior surface of the median nerve and the deep surface of the flexor digitorum superficialis muscle.…”

Erfolgreiche freie mikrovaskuläre A. radialis-Lappenplastik zur Phalluskonstruktion bei persistierender A. mediana (PMA)

“…Bei der PMA handelt es sich um ein "Überbleibsel" aus der Embryonalentwicklung, da die Arterie sich normalerweise in der achten Woche der Schwangerschaft durch Apoptose zurück entwickelt und den Platz für die A. ulnaris und die A. radialis freigibt [2]. Im Zuge der Embryonalentwicklung scheint ihr Vorläufer, die A. axis, zunächst hauptverantwortlich für die Versorgung der Hand zu sein [3,4]. Es existieren zwei Varianten der PMA, erstens der antebrachiale Typ, welcher üblicherweise im proximalen Unterarmbereich endet und eine Inzidenz von 76 % aufweist und zweitens der im Folgenden betrachtete palmare Typ, der als anatomische Variante gilt.…”

“…Insgesamt liegt die Inzidenz anatomischer Variationen der arteriellen Hauptgefäße der oberen Extremität, nach Panagouli, zwischen 11 % und 24 % [25]. Eine veränderte Furkation der embryonal angelegten A. axis und die Persistenz der A. mediana parallel zum Nervus medianus stellen dabei eine typische Anomalie dar und sind häufig verbunden mit weiteren veränderten Lagebeziehungen des Gefäßsystems des Arms [2,3,26]. Dabei kann die Bifurkationsstelle einer persistierenden A. mediana sowohl ausgehend von der A. radialis als auch von der A. ulnaris lokalisiert sein [2].…”