Paraskevas George K, Natsis Konstantinos, Nitsa Zoe, Mavrodi Alexandra, Kitsoulis Panagiotis
Department of Anatomy, Faculty of Medicine, Aristotle University of Thessaloniki, Greece;
Rom J Morphol Embryol. 2014;55(3):993-6.
Ansa cervicalis presents great anatomic variability regarding its origin and formation, the number of its roots and its distribution, as well. In the current case, we report an aberrancy in the form and distribution of ansa cervicalis' branches to the infrahyoid muscles and the sternocleidomastoid muscle, which is unique, since, to the best of our knowledge, a similar case has not been recorded in the literature. During regular dissection, we detected that the ansa cervicalis' loop, which was formed underneath the superior belly of the omohyoid muscle, provided a branch for the sternothyroid muscle, from which two recurrent rami were arisen. These two rami joined together forming an unusual triangular nerve formation. The neural trunk formed by the union of the aforementioned two rami perforated the inferior belly of the omohyoid muscle and afterwards was directed towards the ipsilateral sternocleidomastoid muscle. The awareness of such an unusual variability to the surgeons of the head and neck region would be of great importance, since it is crucial not to damage the ansa cervicalis or its branches in order to prevent any possible phonation disorders. Additionally, ansa cervicalis is proved to be extremely useful in the re-innervation of the larynx following paralysis of the recurrent laryngeal nerve.
颈袢在其起源、形成、神经根数量及其分布方面存在很大的解剖变异。在当前病例中，我们报告了颈袢分支至舌骨下肌群和胸锁乳突肌的形态及分布异常，这种情况很独特，因为据我们所知，文献中尚未记录过类似病例。在常规解剖过程中，我们发现颈袢在肩胛舌骨肌上腹下方形成的袢为胸骨甲状肌发出一支，由此发出两支返支。这两支返支汇合形成一个不寻常的三角形神经结构。由上述两支返支汇合形成的神经干穿过肩胛舌骨肌下腹，然后指向同侧胸锁乳突肌。对于头颈区域的外科医生而言，了解这种不寻常的变异非常重要，因为为防止任何可能的发声障碍，不损伤颈袢或其分支至关重要。此外，事实证明，颈袢在喉返神经麻痹后对喉部的再支配方面极其有用。
