Analysis on the causes of dysphagia after multilevel anterior cervical discectomy and fusion

Abstract

Objective To investigate incidence and related factors of dysphagia after fusion with an anterior cervical plate plus cage or a stand-alone cage (Zero-p cage) following anterior cervical discectomy procedure for treating multilevel cervical spondylotic myelopathy (MCSM).Methods From September 2008to September 2011,226 patients with MCSM underwent anterior cervical discectomy and fusion using an anterior cervical plate plus cage (118 patients,P&C group) or a stand-alone cage (108 patients,Zero-p group).Neurological function was evaluated by Japan orthopedic association (JOA) scores before and after operation.Cervical X-rays were taken to assess the graft fusion,internal fixation related complications and the thickness of the prevertebral soft tissue.The Bazaz dysphagia score and Swallowing Quality of Life questionnaire were used to assess the incidence and degree of dysphagia.Results The average follow-up time was 2.4years (range,1.0 to 3.5 years).The incidence of dysphagia was 41.53％ in P&C group,while 33.33％ in Zero-p group at 2 days after operation.The thickness of the prevertebral soft tissue in P&C group was significantly thicker than that in Zero-p group at 2 days and 2 months after surgery.In Zero-p group,the incidence of dysphagia was 43.1％ in patients who underwent operation from C3 to C6,while 22％ in patients who underwent operation from C4 to C7.Conclusion Dysphagia is common after multilevel anterior cervical discectomy and fusion.The choice of implants and the extent of operation are important influencing factors of postoperative dysphagia.The use of stand-alone cage can decrease the incidence of dysphagia.The operation at higher levels has a higher incidence of dysphagia. Key words: Cervical vertebrae; Spinal cord compression; Spinal fusion; Deglutition disorders