Variation in brachial plexus formation, branching pattern and relation with major vessels
Keywords:Brachial plexus, Branching pattern, Anatomical variation
Background: Anatomical variations in the formation, branching pattern and relations of the brachial plexus have been described in humans by many authors; however these have not been extensively catalogued. The aim of the study was to describe variations in brachial plexus formation, branching pattern and relation with major vessels.
Methods: This study included thorough dissection of 60 brachial plexuses which belonged to 30 cadavers (male: female ratio = 28:02 ) with age range of 20-60 years, obtained from the Department of Anatomy, College of Medical Sciences (CMS-TH), following standard guidelines.
Results: Out of 60 limbs dissected in present study, the variation in formation was found in 20 limbs (33.3%), out of which 12 limbs (20%) had variations in the trunk and 8 limbs (13.3%) had variations in the cord, remaining 40 limbs (66.6%) were normal in the formation of brachial plexus. Normal branching pattern of the posterior cord was encountered in 52 (86.67%) limbs, the remaining 8 (13.33%) being variants in one form or the other. The upper subscapular nerve, the thoracodorsal nerve, the lower subscapular nerve and the axillary nerve were found to arise normally in 91.66%, 96.66%, 96.66% and 98.33% of the limbs respectively.
Conclusion: The present study carried out on adult human cadavers revealed some rare variations in the formation, branching pattern and relations of the brachial plexus. These variations are of clinical significance for the surgeons, radiologists and the anesthesiologists.
Standring S, Ellis H, Healy JC, Johnson D, Williams A, Collins P et al. Gray’s Anatomy. In: Pectoral girdle, shoulder region and axilla. 39th ed. Elsevier Churchill Livingstone. Philadelphia. 2005; p. 846-8.
Datta AK. Essentials of Human Anatomy- Superior and Inferior Extremities. In: The Axilla. 4th ed. Current Books International. Kolkata. 2009. p. 49-52.
Matejcik V. Aberrant formation and clinical picture of brachial plexus from the point of view of
a neurosurgeon. Bratisl. Lek. Listy. 2003; 104:
Matejcik V. Variations of nerve roots of the brachial plexus. Bratisl. Lek. Listy. 2005; 106: 34–6.
Lee HY, Chung IH, Sir WS et al. Variations of the ventral rami of the brachial plexus. J. Korean Med. Sci. 1992; 7:19–24.
Matejcik V. Anatomic variations in the brachial plexus trunks and nerve roots. Rozhl. Chir. 2003; 82:456–9.
Uysal II, Seker M, Karabulut AK et al. Brachial plexus variations in human fetuses. Neurosurgery. Sep 2003; 53(3): 676-84; discussion 684.
Satheesha N, Nagabhooshana S, Venkata R et al. A rare variation in the formation of the upper trunk of
the brachial plexus. Neuroanatomy. 2005; 4: 37-8.
Harry WG, Bennett JD, Guha SC. Scalene muscles and the brachial plexus: anatomical variations and their clinical significance. Clin. Anat. 1997; 10: 250–2.
Kerr AT. The brachial plexus of nerves in man, the variations in its formation and branches. Am J Anat. 1918; 23: 285–395.
Fazan VPS, Amadeu ADS, Caleffi AL et al. Brachial plexus variations in its formation and main branches. Acta Cir Bras. 2003; 18 (5): 1-8.
Ballesteros LE, Ramirez LM. Variations of the origin of the collateral branches which emerge from the posterior aspect of the brachial plexus. Journal of Brachial Plexus and Peripheral Nerve Injury. 2007; 2:14 Doi: 10.1186/1749-7221-2-14.
Miller RA. Comparative studies upon the morphology and distribution of the brachial plexus. Am J Anat. 1934; 54: 143–75.
Poynter CWM. Congenital anomalies of the arteries and veins of the human body with bibliography. University Studies, University of Nebraska. 1920; 22:1-106.
Linell EA. The distribution of nerves in the upper limb, with reference to variabilites and their clinical significance. J Anat. 1921; 79-112.
Hovelacque A. Anatomie des nerfs craniens et rachidiens et Edinburgh. 1995; p. 1266-74.
Hirasawa KO. Untersuchengen uber das Periphere Nervous system Plexus brachialis and die Nerven der oberen Extremitat. Arb Anat Inst Kaiserlichen Univ Kyoto. 1931; A2: 135-6.
Benjamin A, Hirshowitz D, Arden GP et al. Doppelosteotomie am Schultergelenk. Orthopade. 1981;10:245-9.