The anatomical structure of the brachial plexus of the guinea pig (cavia porcellus).

Background: In this study, we described the anatomy of the brachial plexus of the guinea pig (Cavia porcellus). The description of the brachial plexus anatomy can contribute to the knowledge of the neuroanatomy of small mammals. Furthermore, it is a source of information for clinicians performing brachial plexus anesthesia in exotic animals such as the guinea pig (Cavia porcellus).

Materials and methods: Caviaporcellus cadavers were fixed in a 10% formalin solution. The examination of 20 specimens of this species allowed us to assess the extent of the brachial plexus, the nerves exiting it, and the extent of their innervation. Most commonly, it consisted of C6-T1 but could also include branches of C5 and T2. The plexus consisted of three trunks and four cords. We distinguished 15 nerves: n. subclavius, n. brachiocephalicus, n. dorsalis scapulae, n. suprascapularis, nn. subscapulares, n. axillaris, n. musculocutaneus, nn. pectorales craniales, n. radialis, n. medianus, n. ulnaris, n. thoracodorsalis, n. thoracicus lateralis, n. thoracicus longus, and nn. pectorales caudales. We elaborated the innervation range of all identified nerves and updated data from existing papers.

Results: We presented the detailed anatomy of the n. musculocutaneous, brachiocephalicus, and pectoral nerves, which were not distinguished in previous papers or for which the structure was insufficiently known, and compared our results with existing work.

Conclusions: Based on the innervation and the extent of the plexus, it can be confirmed thatCavia porcellushas a brachial plexus with a structure that is characteristic of rodents.