Assessing the association between revision anterior cervical spine surgery for adjacent segment disease and postoperative dysphagia.

OBJECTIVE: Revision surgery is a known risk factor for postoperative dysphagia. This study aimed to assess the association of revision surgeries indicated to treat adjacent segment disease (ASD) with pre- and postoperative dysphagia rates. METHODS: A prospectively collected quality registry for anterior cervical spine surgery was retrospectively reviewed. Eating Assessment Tool-10 (EAT-10) dysphagia questionnaire responses were collected at baseline and at 1, 3, and 12 months postoperatively, using scores ≥ 3 to represent dysphagia. Revision surgeries indicated for ASD were compared against primary surgeries, and univariate analysis assessed differences in patient demographics, surgical information, and patient-reported outcome measures. Fixed-effects logistic regressions were performed to assess the independent impact of ASD on postoperative dysphagia and to identify risk factors within revision surgery. RESULTS: Of the 1713 patients in the cervical spine registry meeting the inclusion criteria, 279 (16.3%) had preoperative ASD while 1434 (83.7%) were primary surgeries. ASD was associated with a higher incidence of dysphagia at 1 (65% vs 57%, p = 0.024), 3 (43% vs 30%, p < 0.001), and 12 months (35% vs 26%, p = 0.018), but not at baseline (15% vs 12%, p = 0.11). Among patients without baseline dysphagia, patients with ASD were significantly more likely to report new dysphagia at 3 months (38% vs 26%, p < 0.001) but not at 1 (59% vs 54%, p = 0.2) or 12 months (26% vs 21%, p = 0.2). Among patients with baseline dysphagia, the average EAT-10 score improved from baseline to 12 months postoperatively, but patients with ASD experienced significantly less improvement (-1.414 [SD 8.399] vs -5.793 [SD 9.217], p = 0.011). In the multivariable analyses of all patients, ASD was an independent predictor of dysphagia at 3 months (OR 1.11, p < 0.001) but not at 1 (OR 1.03, p = 0.4) or 12 months (OR 1.05, p = 0.2). Among patients with ASD, 3-month dysphagia was independently predicted by baseline dysphagia (OR 1.42, p < 0.001), C3-4 exposure (OR 1.27, p = 0.004), and re-exposure of prior levels (OR 1.16, p = 0.024), while an otolaryngologist-assisted approach predicted a lower risk (OR 0.77, p = 0.022). CONCLUSIONS: ASD did not significantly impact baseline dysphagia rates, but revision surgery for ASD was a significant independent risk factor for delayed recovery from initial postoperative dysphagia beyond 3 months following anterior cervical spine surgery. Exposure-related variables further stratified risk within ASD revision surgery. Preoperative patient counseling should manage patient expectations accordingly.