Singh Rajani
Department of Anatomy, AIIMS, Rishikesh, India.
J Craniofac Surg. 2017 Mar;28(2):543-547. doi: 10.1097/SCS.0000000000003341.
Brachial plexus is complex network of nerves, formed by joining and splitting of ventral rami of spinal nerves C5, C6, C7, C8, and T1 forming trunks, divisions, and cords. The nerves emerging from trunks and cords innervate the upper limb and to some extent pectoral region. Scanty literature describes the variations in the formation of cords and nerves emanating from them. Moreover, the variations of cords of brachial plexus and nerves emanating from them have iatrogenic implications in the upper limb and pectoral region. Hence study has been carried out. Twenty-eight upper limbs and posterior triangles from 14 cadavers fixed in formalin were dissected and rare and new variations of cords were observed. Most common variation consisted of formation of posterior cord by fusion of posterior division of upper and middle trunk and lower trunk continued as medial cord followed by originating of 2 pectoral nerves from anterior divisions of upper and middle trunk. Other variations include anterior division of upper trunk continued as lateral cord and pierced the coracobrachialis, upper and middle trunk fused to form common cord which divided into lateral and posterior cords, upper trunk gave suprascapular nerve and abnormal lateral pectoral nerve and formation of median nerve by 3 roots. These variations were analyzed for diagnostic and clinical significance making the study relevant for surgeons, radiologists in arresting failure patients and anatomists academically in medical education.
臂丛神经是一个复杂的神经网络，由颈5、颈6、颈7、颈8和胸1脊神经前支相互连接和分支形成干、股、束。从干和束发出的神经支配上肢，并在一定程度上支配胸肌区域。关于束的形成及其发出神经的变异的文献较少。此外，臂丛神经束及其发出神经的变异在上肢和胸肌区域具有医源性影响。因此开展了此项研究。对14具用福尔马林固定的尸体的28条上肢和后三角进行了解剖，观察到了束的罕见和新的变异情况。最常见的变异包括上干和中干的后股融合形成后束，下干延续为内侧束，随后从上干和中干的前股发出2条胸神经。其他变异包括上干的前股延续为外侧束并穿经喙肱肌，上干和中干融合形成共同束，该共同束再分为外侧束和后束，上干发出肩胛上神经和异常的胸外侧神经，以及正中神经由3根神经根组成。分析了这些变异的诊断和临床意义，使该研究对外科医生、处理衰竭患者的放射科医生以及医学教育领域的解剖学家具有学术相关性。
