Jian Qiang, Hou Zhe, Fan Tao
Spine Center, Sanbo Brain Hospital, Capital Medical University, Beijing, People's Republic of China.
Spine Center, Sanbo Brain Hospital, Capital Medical University, Beijing, People's Republic of China.
World Neurosurg. 2023 Apr;172:72. doi: 10.1016/j.wneu.2023.01.033. Epub 2023 Feb 2.
Type B basilar invagination (BI) refers to odontoid process prolapse into skull base without dislocation, which is often associated with Chiari malformation and syringomyelia. Its pathogenesis and treatment are in controversy. Posterior fossa decompression has been introduced to treat the associated Chiari malformation; however, it may not be effective for symptoms with severe ventral nerve compression. C1-2 in situ fixation has been reported to treat minor instability in type B BI, yet the assessment of minor instability has not been widely accepted. We believe that the pathogenesis is chronic ventral compression of the brainstem. Transoral odontoidectomy is a classic surgical procedure to treat the pathogenesis, but it is associated with high risks of infection, velopharyngeal incompetence, and airway obstruction and often requires posterior surgery for fusion. Thus we use an interfacet distraction technique to move the odontoid process down and relieve ventral brainstem compression. Therefore interfacet structural support is necessary to maintain the distance of the interfacet. The reason for fixation is that interfacet distraction disrupts atlantoaxial stability. We designed a novel sliding-traction head holder, which can quantitatively tract and stabilize the head without support for the head or face, avoiding the risk of eyeball compression. It adapts to a variety of surgical methods and allows intraoperative changes in the patient's position. Assisted by the device, a satisfied interfacet distraction and a correction of BI were obtained. Video 1 describes how the interfacet distraction technique assisted by a sliding-traction head holder was performed in an illustrative case. The patient consented to the procedure.
B型基底凹陷症（BI）是指齿状突向颅底脱垂但无脱位，常与Chiari畸形和脊髓空洞症相关。其发病机制和治疗存在争议。后颅窝减压术已被用于治疗相关的Chiari畸形；然而，对于严重腹侧神经受压的症状可能无效。据报道，C1-2原位固定可治疗B型BI的轻度不稳定，但对轻度不稳定的评估尚未被广泛接受。我们认为其发病机制是脑干的慢性腹侧受压。经口齿状突切除术是治疗该发病机制的经典手术，但它与感染、腭咽功能不全和气道梗阻的高风险相关，且通常需要进行后路融合手术。因此，我们采用关节突撑开技术将齿状突向下移动并缓解脑干腹侧受压。因此，关节突结构支撑对于维持关节突间距是必要的。固定的原因是关节突撑开破坏了寰枢椎稳定性。我们设计了一种新型滑动牵引头架，它可以在不支撑头部或面部的情况下对头部进行定量牵引和稳定，避免眼球受压的风险。它适用于多种手术方法，并允许术中改变患者体位。在该装置的辅助下，获得了满意的关节突撑开效果并矫正了基底凹陷症。视频1描述了在一个典型病例中如何在滑动牵引头架辅助下进行关节突撑开技术。患者同意了该手术。
