Okamoto Naoki, Azuma Seiichi
Department of Orthopedics, Saitama Red Cross Hospital, Saitama, Japan.
Spine Surg Relat Res. 2018 Feb 28;2(2):121-126. doi: 10.22603/ssrr.2017-0064. eCollection 2018.
During upper cervical anterior fusion involving C2, the branches of the superior laryngeal and hypoglossal nerves traversing the operative field are at risk for injury, mainly from excessive retraction and/or incidental ligation. These injuries would cause postoperative dysphagia and/or dysphonia that are often transient but might sometimes persist for several months. The aim of this study was to describe our modified approach for upper cervical anterior fusion and to examine the surgical outcomes and postoperative complications in a small case series.
Four patients underwent upper cervical anterior fusion at our institution. Detaching the omohyoid and sternohyoid muscles from the hyoid bone increased the mobility of the hyoid bone and enabled visualization of the thyrohyoid membrane. This maneuver facilitated access to C2 without excessive retraction to the larynx and the hypoglossal nerve traversing above the hyoid bone. Moreover, this maneuver enabled easy identification and dissection of the internal branch of the superior laryngeal nerve piercing the thyrohyoid membrane.
Three patients underwent C2-3 fusion and one patient underwent C2-5 fusion followed by instrumentation. In all patients, wide, adequate exposure of C2 and proper instrumentation was achieved, and both the internal branch of the superior laryngeal nerve and the hypoglossal nerve were identified and preserved. No patient experienced remarkable postoperative dysphagia, dyspnea, and dysphonia. Solid union was achieved in all patients.
The technique of detaching the infrahyoid muscles from the hyoid bone during upper cervical anterior fusion involving C2 reduced the traction force to the larynx and the hypoglossal nerve, enabled easy identification of the internal branch of the superior laryngeal nerve, and prevented postoperative complications, such as dysphagia.
在涉及C2的上颈椎前路融合手术中，穿过手术视野的喉上神经和舌下神经分支有受伤风险，主要是由于过度牵拉和/或意外结扎。这些损伤会导致术后吞咽困难和/或声音嘶哑，通常是短暂的，但有时可能会持续数月。本研究的目的是描述我们改良的上颈椎前路融合手术方法，并在一个小病例系列中检查手术结果和术后并发症。
4例患者在我院接受了上颈椎前路融合手术。将肩胛舌骨肌和胸骨舌骨肌从舌骨上分离，增加了舌骨的活动度，使甲状舌骨膜得以显露。这一操作便于在不过度牵拉喉部和穿过舌骨上方的舌下神经的情况下接近C2。此外，这一操作能够轻松识别和解剖穿过甲状舌骨膜的喉上神经内支。
3例患者接受了C2-3融合术，1例患者接受了C2-5融合术并进行了内固定。所有患者均实现了对C2的广泛、充分暴露和适当的内固定，喉上神经内支和舌下神经均被识别并保留。没有患者出现明显的术后吞咽困难、呼吸困难和声音嘶哑。所有患者均实现了牢固融合。
在涉及C2的上颈椎前路融合手术中，将舌骨下肌群从舌骨上分离的技术减少了对喉部和舌下神经的牵引力，便于轻松识别喉上神经内支，并预防了术后并发症，如吞咽困难。
