Realistic long-term dysphagia rates after anterior cervical discectomy with fusion: is there a correlation with postoperative sagittal alignment and lordosis at a minimum 2-year follow-up?

Abstract

Postoperative dysphagia after anterior cervical discectomy and fusion (ACDF) has many contributing factors, and long-term data are sparse. The authors evaluated dysphagia after ACDF based on levels fused and cervical sagittal parameters. Patients who underwent ACDF between 2009 and 2018 at the University of California, San Francisco (UCSF), were retrospectively studied. Dysphagia was evaluated preoperatively, immediately postoperatively, and at last follow-up using the UCSF dysphagia score. Dysphagia was categorized as normal (level 7), mild (levels 5 and 6), moderate (levels 3 and 4), and severe (levels 1 and 2). The UCSF mild dysphagia score was further classified as "minimal dysphagia," while moderate and severe dysphagia were classified as "significant dysphagia." "Any dysphagia" included any dysphagia, regardless of grade. Cervical sagittal parameters were measured preoperatively, immediately postoperatively, and at last follow-up. A total of 131 patients met inclusion criteria. The mean follow-up was 43.89 (24-142) months. Seventy-eight patients (59.5%) reported dysphagia immediately postoperatively, and 44 patients (33.6%) reported some dysphagia at last follow-up (p < 0.001). The rates of moderate dysphagia were 13.0% immediately postoperatively and 1.5% at the last follow-up (p < 0.001). Twenty-two patients (16.8%) had significant dysphagia immediately postoperatively, and 2 patients (1.5%) had significant dysphagia at last follow-up (p < 0.001). Patients with immediate postoperative dysphagia had less C2-7 preoperative lordosis (-9.35°) compared with patients without (-14.15°, p = 0.029), but there was no association between C2-7 lordosis and dysphagia at last follow-up (p = 0.232). The prevalence rates of immediate postoperative dysphagia and long-term dysphagia were 87.5% and 58.3% in ≥ 3-level ACDF; 64.0% and 40.0% in 2-level ACDF; and 43.9% and 17.5% in 1-level ACDF, respectively (p < 0.001). The realistic incidence of any dysphagia after ACDF was 59.5% immediately postoperatively and 33.6% at the minimum 2-year follow-up, higher than previously published rates. However, most dysphagia was not severe. The number of fused levels was the most important risk factor for long-term dysphagia, but not for immediate postoperative dysphagia. Loss of preoperative C2-7 lordosis was associated with immediate postoperative dysphagia, but not long-term dysphagia. ACDF segmental lordosis and cervical sagittal vertical axis were not associated with long-term dysphagia in ACDF.