Influence of prevertebral soft tissue swelling on dysphagia after anterior cervical discectomy and fusion using a rectangular titanium stand-alone cage

BACKGROUND: Postoperative oropharyngeal complications such as dysphagia after anterior cervical spine surgery are some of the least discussed surgery-related complications. The purpose of this retrospective study is to investigate the incidence and possible risk factors for 30-day postoperative dysphagia after anterior cervical discectomy and fusion (ACDF). MATERIALS AND METHODS: This study included 152 consecutive patients who underwent 1- or 2-level ACDF using a rectangular titanium stand-alone cage in our institutes. Surgery-related dysphagia early after surgery was analyzed based on hospital charts. Radiological evaluation of prevertebral soft tissue swelling (PSTS) was performed by comparing plain lateral radiographs of the cervical spine before surgery with those after surgery. The percentage of PSTS (%PSTS) was defined by retropharyngeal soft tissue diameter divided by vertebral diameter. Positive %PSTS was determined when %PSTS exceeded its mean + 2 standard deviations. RESULTS: Twelve patients (7.9%) demonstrated prolonged symptoms of dysphagia within 30-day postoperatively. All patients eventually demonstrated satisfactory or acceptable recovery late after surgery, except one case of hypoglossal nerve palsy. %PSTS was significantly highest early after surgery and returned to presurgical levels within 30 days after surgery. Statistical analysis suggested that the positive %PSTS at C3 or C4 level early after surgery was significantly associated with the occurrence of postoperative dysphagia. CONCLUSIONS: Although the possible reasons for postoperative dysphagia may not only be multifactorial but also be highly surgeon-dependent, such a complication is still underestimated and needs to be carefully resolved. %PSTS appeared to be easy and reliable index to judge the possible risk of postoperative dysphagia.