Surgical outcomes of dysphagia provoked by diffuse idiopathic skeletal hyperostosis in the cervical spine

Purpose: This study aimed to predict the surgical outcomes of diffuse idiopathic skeletal hyperostosis (DISH)-related dysphagia (DISH-phagia) and to evaluate the importance of prevertebral soft tissue thickness (PVST). Materials and Methods: In total, 21 surgeries (anterior osteophytectomy or anterior cervical decompression and fixation) were included in this study for DISH-phagia from 2003 to 2019. Clinical outcomes were assessed using the Dysphagia Outcome and Severity Scale (DOSS) preoperatively, at 1 month postoperatively, and last follow up (mean 29.5 months). PVST was measured using lateral plain radiographs. Paired t-test and Spearman’s correlation test was used to identify relationships between various PVST indices and DOSS. Results: Comparisons were made from 17 patients out of 21, in which the record had all of three measurements. The narrowest PVST preoperatively was 2.55±0.90 mm, with a DOSS score of 4.47±1.61, and that at 1 month after surgery was 5.02±2.33 mm, with a DOSS score of 6.12±1.32. At last follow up, PVST and DOSS values were 3.78±0.92 mm and 5.82±1.34, and three patients experienced symptom relapse. Significant relationships were found between PVST and DOSS at all time points: before surgery (R=0.702, p<0.001), 1 month after surgery (R=0.539, p=0.012), and last follow up (R=0.566, p=0.020). Conclusion: Surgical removal of anterior osteophytes is an effective treatment option for DISH-phagia, and PVST is a useful parameter in DISH-phagia. The goal of DISH surgery should be to remove DISH as much as possible to ensure sufficient PVST post-operatively.