Long-term dysphagia after multilevel anterior decompressive surgery for cervical myelopathy: findings from the phase III CSM-Protect trial.

OBJECTIVE

Dysphagia is a common early complication after anterior cervical spine surgery, yet its long-term natural history and risk factors remain incompletely understood, particularly in multilevel procedures for degenerative cervical myelopathy (DCM). This study aimed to characterize the natural history of postoperative dysphagia and identify predictors of persistent dysphagia at 12 months.

METHODS

Adult patients who received anterior decompression for DCM between 2012 and 2017 and were prospectively enrolled as part of the CSM-Protect trial were retrospectively reviewed. Presence and severity of dysphagia were assessed with the Bazaz scale (none, mild, moderate, or severe) at baseline and 35, 180, and 365 days postoperatively. Multivariable logistic regression controlling for study randomization and site were used to identify risk factors for dysphagia at 365 days.

RESULTS

From a total of 290 patients, 132 subjects met the eligibility criteria. Preoperatively, 11.4% of patients had moderate dysphagia. Dysphagia peaked at 35 days with 68.6% of all patients (14% severe) before declining to 47% at 180 days and 36.4% at 365 days. At 1 year, 10.6% had moderate dysphagia and 3.0% severe. Multivariable analysis demonstrated that anterior surgery at the C5 level (OR 4.52, 95% CI 1.16-19.4, p = 0.034), baseline dysphagia (OR 4.56, 95% CI 1.74-12.9, p = 0.003), and shorter duration of myelopathic symptoms (OR 0.98 per month, 95% CI 0.97-0.98, p = 0.027) were independently associated with persistent dysphagia.

CONCLUSIONS

In this cohort of primarily multilevel anterior cervical surgical procedures, postoperative dysphagia peaked early but remained common at 1 year. Baseline dysphagia, C5-level involvement, and shorter symptom duration were key predictors of long-term dysphagia.