Risk Factors for and Clinical Outcomes of Dysphagia After Anterior Cervical Surgery for Degenerative Cervical Myelopathy: Results from the AOSpine International and North America Studies.

Background: Although dysphagia is a common complication after anterior cervical decompression and fusion, important risk factors have not been rigorously evaluated. Furthermore, the impact of dysphagia on neurological and quality-of-life outcomes is not fully understood. The aim of this study was to determine the prevalence of and risk factors for dysphagia, and the impact of this complication on short and long-term clinical outcomes, in patients treated with anterior cervical decompression and fusion.
Methods: Four hundred and seventy patients undergoing a 1-stage anterior or 2-stage anteroposterior cervical decompression and fusion were enrolled in the prospective AOSpine CSM (Cervical Spondylotic Myelopathy) North America or International study at 26 global sites. Logistic regression analyses were conducted to determine important clinical and surgical predictors of perioperative dysphagia. Preoperatively and at each follow-up visit, patients were evaluated using the modified Japanese Orthopaedic Association scale (mJOA), Nurick score, Neck Disability Index (NDI), and Short Form-36 Health Survey (SF-36). A 2-way repeated-measures analysis of covariance was used to evaluate differences in outcomes at 6 and 24 months between patients with and those without dysphagia, while controlling for relevant baseline characteristics and surgical factors.
Results: The overall prevalence of dysphagia was 6.2%. Bivariate analysis showed the major risk factors for perioperative dysphagia to be a higher comorbidity score, older age, a cardiovascular or endocrine disorder, a lower SF-36 Physical Component Summary score, 2-stage surgery, and a greater number of decompressed levels. Multivariable analysis showed patients to be at an increased risk of perioperative dysphagia if they had an endocrine disorder, a greater number of decompressed segments, or 2-stage surgery. Both short and long-term improvements in functional, disability, and quality-of-life scores were comparable between patients with and those without dysphagia.
Conclusions: The most important predictors of dysphagia are an endocrine disorder, a greater number of decompressed levels, and 2-stage surgery. At the time of both short and long-term follow-up, patients with perioperative dysphagia exhibited improvements in functional, disability, and quality-of life scores that were similar to those of patients without dysphagia.
Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.