The upper brachial plexus defect model in rhesus monkeys

Abstract

To establish a model for nerve grafts and determine the anatomic characteristics of the brachial plexus in rhesus monkeys. Ten specimens of the brachial plexus were obtained from five rhesus monkey cadavers. Anatomic dissection of the brachial plexus was systemically performed. The length of each root, trunk, and each division was measured using a Vernier caliper proximodistally. The anatomic distributions of the suprascapular, axillary, and musculocutaneous nerve were documented. The brachial plexus of rhesus monkeys included the spinal nerves or roots of C5, C6, C7, C8, and T1 (80%, 8/10), with a small contribution from the C4 root (20%, 2/10) occasionally. The upper trunk was not measurable because of their irregular structures. The lower trunk had a mean length of 1.62 (range, 0.96-2.1 mm) and a mean diameter of 2.29 (range, 1.9-2.94 mm). For the upper trunk, the C5 and C6 roots either divided into two very short divisions or sent out very long divisions before they joined together. For the middle trunk, the C7 root had a straight course after leaving the foramen and blended imperceptibly into the middle trunk before dividing into the anterior and posterior divisions. The lower trunk was noted in almost all the specimens (80%, 8/10), which was formed by C8 and T1. The brachial plexus in rhesus monkeys varies from that of humans, and defects can be made at the level of C5 and C6 roots and the C7 root should also be cut off and ligated.

Origin and antimeric distribution of brachial plexus nerves in Macaca mulatta (Zimmermann, 1780) (Primates: Cercopithecidae)

“…Studies involving the anatomy of the brachial plexus and its applications in experimental models have been proposed and carried out in rats, dogs, cats, rabbits and other species (Getty 1986;Anson et al 2013;Bobkiewicz et al 2016). However, Lu et al (2013) reported that non-human primates are considered more adequate experimental models for training and development of new techniques and materials for humans due to the anatomic similarity of their brachial plexuses and mode of locomotion.…”

“…However, the authors emphasised comparative anatomy aspects (Kanagasuntheram & Mahran 1960;Mizuno 1969;Booth et al 1997;Ribeiro et al 2005;Cruz & Adami 2010;Araújo et al 2012). Even when an experimental model approach was considered (Lu et al 2013), peripheral nerves as well as their frequency and the muscles that were innervated by them were not completely recorded. This kind of information is important when new approaches and techniques involving thoracic limbs are used.…”

“…As non-human primates have a complex locomotor system, similar to that of humans, the study of the brachial plexus in these animals provides an anatomical basis for models of plexus defects, besides the evaluation of viability and efficacy of new materials and techniques for surgical procedures that aim at recovering and restoring the function of the branches, nerves and nerve trunks (Lu et al 2013).…”

Origin and antimeric distribution of brachial plexus nerves inAlouatta guariba clamitansCabrera, 1940 (Primates: Atelidae)

“…Among the 10 dissected plexuses, all presented their origin in the ventral branches of C5 to T1, although in one animal there was a delicate contribution of C4, and in another one there was a delicate contribution of T2. The origin of the plexus between C5 and T1 is very nearly a rule for primates, having been reported in G. senegalensis (Kanagasuntheram & Mahran 1960), S. sciureus (Mizuno 1969), P. ursinus (Booth et al 1997 (Lu et al 2013;Santos-Sousa et al 2016) and human beings (Parada et al 1989;Zhang et al 2016). However, intraspecific variations concerning the spinal segments of origin are also reported in those studies that used more specimens, as in the case of C. apella (Ribeiro et al 2005) and M. mulatta (Santos-Sousa et al 2016).…”

“…Galago senegalensis senegalensis (Kanagasuntheram & Mahran 1960); Saimiri sciureus (Mizuno 1969;Araújo et al 2012); Cercopithecus pygerythrus (Booth 1991); Papio ursinus (Booth et al 1997); Cebus apella (Ribeiro et al 2005); Lagothrix lagothricha (Robertson 1944;Cruz & Adami 2010); Pan paniscus (Kikuchi et al 2011); Macaca mulatta (Lu at al. 2013;Santos-Sousa et al 2016); and Callithrix jacchus and Callithrix penicillata .…”