Dysphagia after anterior cervical discectomy and fusion: a prospective study comparing two anterior surgical approaches

Background The Smith-Robinson approach is commonly used to expose the vertebrae in anterior cervical discectomy and fusion (ACDF). Postoperative dysphagia has been frequently reported following this procedure. In this approach, surgical dissection can be carried out either lateral (LEO) or medial (MEO) to the omohyoid muscle. The purpose of this study was to compare the degree of dysphagia between the LEO and MEO groups. Methods In this randomized, prospective study, 80 patients were enrolled and evenly divided into the MEO and LEO groups. Patients underwent two-level ACDF using a right-sided Smith-Robinson approach. Follow-up was obtained 1, 3, 6, 12 week and 6 months after surgery. The degree of dysphagia was assessed using a 14-item questionnaire from the SWAL-QOL survey. Results There were no differences between the MEO and LEO groups with respect to age, gender, body mass index, or length of surgery. Overall, the SWAL-QOL scores were not different between the two groups at any of the follow-up time points. However, when the level of surgery was taken into consideration, the early postoperative SWAL-QOL scores were significantly lower in the C3-C4 subgroup when the MEO approach was used. Conversely, the SWAL-QOL scores were significantly lower in the C6-C7 subgroup when the LEO approach was used. Two patients with C6-C7 surgery in the MEO group also developed dysphonia that resolved spontaneously within 3 months. Conclusion The findings from this study suggest that the LEO approach should be selected if the level of surgery involves C3-C4. For C6-C7 surgery, however, a left-sided MEO approach should be used. Depending on surgeon's preference, either approach can be used if both cervical levels are involved.