Variations of the ventral rami of the brachial plexus

Abstract

We studied the variations in the ventral rami of 152 brachial plexuses in 77 Korean adults. Brachial plexus were composed mostly of the fifth, sixth, seventh and eighth cervical nerves and the first thoracic nerve (77.0%). In 21.7% of the cases examined, the fourth, fifth, sixth, seventh and eighth cervical and the first thoracic nerves contributed to the plexus. A plexus composed of the fourth, fifth, sixth, seventh and eighth cervical and the first and second thoracic nerves, and a plexus composed of the fifth, sixth, seventh eighth cervical nerves were also observed. The plexuses were classified into three groups according to cephalic limitation, and the plexus of group 2 in which the whole fifth cervical nerve enters the plexus, were observed the most frequent. The average diameter of the sixth and the seventh cervical ventral rami of the plexus was greatest and that of the fifth cervical was smallest. The largest nerve entering the plexus was the sixth or the seventh cervical nerve in about 79% of cases. The dorsal scapular nerve originated from the fifth cervical ventral ramus in 110 cases (75.8%). The long thoracic nerve was formed by joining of roots from the fifth, sixth, and seventh cervical nerves in 76.0% of cases. Also, a branch to the phrenic nerve, the suprascapular nerve, a nerve to the pectoralis major muscle and a nerve to the subscapular muscle arising from the ventral rami of the plexus were observed.

A Study on the Variations in the Formation of the Trunks of Brachial Plexus

“…In the surgical treatment of brachial plexus lesions, the surgeon must know brachial plexus anatomical variations perfectly. Common variations in the formation, prefixed and postfixed plexuses have been well documented (Matejcik, 2003a(Matejcik, , 2003b(Matejcik, , 2005Lee et al, 1992). Variations in the formation of the trunks of the brachial plexuses have also been reported (Matejcik, 2003b).…”

Vulnerable Neurovasculature with a Posterior Approach to the Scapula

“…Although the suprascapular artery was not quantified, it joined the suprascapular nerve in a neurovascular bundle fashion. The suprascapular nerve is a mixed sensory and motor peripheral nerve arising from the superior trunk of the brachial plexus (C5-C6) with a variable contribution from the fourth cervical nerve root [1,14]. We noted the suprascapular nerve to be in a vulnerable location as it tethers against the base of the acromion through the spinoglenoid notch and before entering the innervated infraspinatus muscle.…”

A Morphometric Aspect of the Brachial Plexus in the Periclavicular Region

“…Some reports state that the C7 and the C8 nerve roots have the largest ventral rami 18) , but others have reported that the largest are associated with the C6 and the C7 nerve roots 13) . Morphometrically, the BP is centered on the C4 nerve root and consists of the C5, C6, C7, and the C8 nerve roots.…”