Kaneyama Shuichi, Sumi Masatoshi, Takabatake Masato, Kasahara Koichi, Kanemura Aritetsu, Koh Akihiro, Hirata Hiroaki
Department of Orthopaedic Surgery, Kobe Rosai Hospital, Kobe, Japan.
Spine (Phila Pa 1976). 2016 Dec 1;41(23):1777-1784. doi: 10.1097/BRS.0000000000001805.
Kinematic analysis of swallowing function using videofluoroscopic swallowing study (VFSS).
The aims of this study were to analyze swallowing process in the patients who underwent occipitospinal fusion (OSF) and elucidate the pathomechanism of dysphagia after OSF.
Although several hypotheses about the pathomechanisms of dysphagia after OSF were suggested, there has been little tangible evidence to support these hypotheses since these hypotheses were based on the analysis of static radiogram or CT. Considering that swallowing is a compositive motion of oropharyngeal structures, the etiology of postoperative dysphagia should be investigated through kinematic approaches.
Each four patients with or without postoperative dysphagia (group D and N, respectively) participated in this study. For VFSS, all patients were monitored to swallow 5-mL diluted barium solution by fluoroscopy, and then dynamic passing pattern of the barium solution was analyzed. Additionally, O-C2 angle (O-C2A) was measured for the assessment of craniocervical alignment.
O-C2A in group D was -7.5 degrees, which was relatively smaller than 10.3 degrees in group N (P = 0.07). In group D, all cases presented smooth medium passing without any obstruction at the upper cervical level regardless of O-C2A, whereas the obstruction to the passage of medium was detected at the apex of mid-lower cervical ocurvature, where the anterior protrusion of mid-lower cervical spine compressed directly the pharyngeal space. In group N, all cases showed smooth passing of medium through the whole process of swallowing.
This study presented that postoperative dysphagia did not occur at the upper cervical level even though there was smaller angle of O-C2A and demonstrated the narrowing of the oropharyngeal space towing to direct compression by the anterior protrusion of mid-lower cervical spine was the etiology of dysphagia after OSF. Therefore, surgeon should pay attention to the alignment of mid-cervical spine as well as craniocervical junction during OSF.
使用视频荧光吞咽造影（VFSS）对吞咽功能进行运动学分析。
本研究旨在分析接受枕颈融合术（OSF）患者的吞咽过程，并阐明OSF术后吞咽困难的发病机制。
尽管有人提出了关于OSF术后吞咽困难发病机制的几种假说，但由于这些假说是基于静态X线片或CT分析，几乎没有确凿证据支持这些假说。鉴于吞咽是口咽结构的复合运动，术后吞咽困难的病因应通过运动学方法进行研究。
分别有4例有或无术后吞咽困难的患者（分别为D组和N组）参与本研究。对于VFSS，通过荧光透视监测所有患者吞咽5毫升稀释钡剂溶液，然后分析钡剂溶液的动态通过模式。此外，测量枕骨至第二颈椎角度（O-C2A）以评估颅颈对线情况。
D组的O-C2A为-7.5度，相对小于N组的10.3度（P = 0.07）。在D组中，无论O-C2A如何，所有病例在颈上段均表现为钡剂顺利通过且无任何梗阻，而在颈中下曲度顶点处检测到钡剂通过梗阻，此处颈中下段脊柱的前凸直接压迫咽腔。在N组中，所有病例在吞咽全过程中钡剂均顺利通过。
本研究表明，即使O-C2A较小，术后吞咽困难也不会发生在颈上段，并证明了由于颈中下段脊柱前凸直接压迫导致口咽间隙变窄是OSF术后吞咽困难的病因。因此，外科医生在进行OSF时应注意颈中段脊柱以及颅颈交界处的对线情况。
4级。
