喉上神经外支和甲状腺上动脉的应用解剖

Applied anatomy of the external laryngeal nerve and superior thyroid artery

目的解剖并观察喉上神经外支(external laryngeal nerve,ELN)和甲状腺上动脉(superior thyroid artery,STA)之间的比邻关系,为手术中保护ELN提供解剖学基础。方法成年尸体标本57具(114侧),在6倍大视场显微镜下解剖并观察ELN、STA的比邻关系。结果本组标本中颈交感链(cervical sympathetic chain,CSC)与ELN吻合成袢(CSC-ELN loop)者,占78.9%(90侧)。在27.7%(25侧)低位CSC-ELN loop中,血管和神经的位置关系可分为4类:(1)STA分支与CSC-ELN loop重叠;(2)STA腺支穿过CSC-ELN loop;(3)CSC-ELN loop环甲肌支与STA喉支伴行;(4)STA的分支与CSC-ELN loop分支相互交叉。结论 STA与CSC-ELN loop之间的关系十分复杂。有鉴于此,在甲状腺和/或颈部手术中,我们特提出两个手术保护措施:(1)应单支游离并结扎STA;(2)在处理STA的前内侧分支时,应注意避免损伤ELN/CSC-ELN loop的环甲肌支。

Objective The topographic relationship between the external laryngeal nerve（ELN） and the superior thyroid artery （STA） were observed, in order to provide the anatomical foundations for protecting the ELN during surgery. Methods Fifty-seven cadavers （114 sides） fixed with formalin were collected at random. The ELN and STA were carefully dissected and analyzed under a 6-power magnifier. Results The cervical sympathetic chain （CSC） of 90 sides was anastomosed with the ELN（CSC-ELN loop）. For the 27.7% （25 sides） low-position CSC-ELN loops observed, the neurovascular relationship between the STA and ELN was classified into four types： ①the branches of the STA overlapped with the CSC-ELN loop; ② the glandular branch of the STA passed through the CSC-ELN loop; ③the muscular branch of the CSC-ELN loop and the laryngeal branch of the STA coursed together;④the branches of the STA and the CSC-ELN loop were interlaced. Conclusion Our study has shown a variable morphology of the CSC-ELN loop and its complicated topographic relationship to the STA, which should be kept in mind when attempting to avoid the nerve injury. Two special surgical procedures are recommended. First, the vessels should be individually isolated and then ligated during thyroidectomy. Second, a special attention should be paid to protect the coricothyroid branch of CSC- ELN loop from injury, when the anteriomedial branches of the STA are to be ligated during larynx surgery.