Nemiroff P M, Katz A D
Am J Surg. 1982 Oct;144(4):466-9. doi: 10.1016/0002-9610(82)90425-1.
Extralaryngeal branches of the recurrent laryngeal nerve have been noted in the literature, but frequently the researchers fail to indicate with accuracy the site of bifurcation. The current study was undertaken to designate the exact level of bifurcation of the recurrent laryngeal nerve, with more precise localization using a standard anatomic landmark. A prospective study based on 83 surgical patients was performed. The location of all nerves was measured using the inferior border of the cricoid cartilage as the anatomic landmark. A total of 153 recurrent laryngeal nerves were observed. Sixty-three (41.2 percent) bifurcated or trifurcated into extralaryngeal branches. Of these, there were four instances of trifurcations. The remaining 59 nerves bifurcated. Of these, 14 nerves bifurcated into equal-sized branches which went in an anterior or posterior direction. The remaining 45 nerve bifurcations indicated that 39 (86.7 percent) of the small branches went in a posterior direction, whereas only 6 (13.3 percent) of the large branches went in that direction. Surgical and clinical implications of this finding were discussed. Two instances of a "nonrecurrent" laryngeal nerve (that occurred on the right side) were also noted. The results of this study demonstrate conclusively that extralaryngeal branches of the recurrent laryngeal nerve are not an anatomic rarity. Therefore, thyroid surgery must include identification and preservation of the recurrent laryngeal nerve and all of its divisions.
文献中已提及喉返神经的喉外分支，但研究人员常常未能准确指出其分支部位。本研究旨在确定喉返神经的精确分支水平，并使用标准解剖标志进行更精确的定位。对83例手术患者进行了一项前瞻性研究。以环状软骨下缘作为解剖标志来测量所有神经的位置。共观察了153条喉返神经。其中63条（41.2%）分叉或分成三叉形成喉外分支。其中有4例三叉分支。其余59条神经分叉。其中，14条神经分成等大分支，分别向前或向后走行。其余45条神经的分叉情况显示，小分支中有39条（86.7%）向后走行，而大分支中只有6条（13.3%）向后走行。讨论了这一发现的手术及临床意义。还发现了2例“非返性”喉神经（均发生在右侧）。本研究结果确凿地表明，喉返神经的喉外分支并非解剖学上的罕见情况。因此，甲状腺手术必须包括识别和保留喉返神经及其所有分支。
