Relationship between preoperative cervical sagittal alignment and prevertebral soft tissue swelling after anterior cervical spine surgery

Abstract

Introduction : Anterior cervical spine surgery is commonly used for treating various conditions like degenerative, traumatic, tumorous, and infectious cervical diseases. While generally safe and effective, complications arise, including dysphagia, hoarseness, dysphonia, recurrent laryngeal nerve palsy, esophageal perforation, and respiratory insufficiency. The purpose of this study was to identify whether the occurrence of prevertebral soft tissue swelling can be predicted through the cervical lordosis parameters that can be measured through preoperative cervical plain radiographs.

Methods : A total of 108 patients who underwent anterior cervical discectomy and fusion or artificial disc replacement between January 1, 2014, and December 31, 2021, were included in this retrospective study. The study excluded 79 patients based on specific exclusion criteria. The patients' clinical information, including sex, age, smoking status, alcohol consumption, BMI, operation time, external blood loss (EBL), hypertension, diabetes, and pre- and post-operative albumin levels, was collected from medical and operative records. Additionally, radiological parameters such as O-C2 angle, C2-7 angle, and T1 slope were measured using the patients' lateral cervical spine radiographs.

Results : In our study, we examined the factors associated with prevertebral soft tissue swelling (PSTS) after anterior cervical discectomy and fusion or artificial disc replacement. We found that BMI, hypertension, diabetes, smoking, and alcohol consumption were not significantly associated with PSTS (P>0.05). However, multi-level surgery and plate fixation were found to be associated with PSTS (P<0.05). Among the radiological parameters we analyzed, only the preoperative segmental angle showed a significant association with PSTS (P<0.05). Other factors, including the delta segmental angle, preoperative O-C2 angle, C2-7 angle, cervical sagittal vertical axis, and T1 slope minus cervical lordosis, did not show a significant association with PSTS (P>0.05). Although preoperative T1 slope showed a negative correlation with PSTS, the correlation was not statistically significant. In the multivariate linear regression analysis, we identified that being female, older age, lower preoperative T1 slope, and undergoing multi-level surgery were significantly associated with a higher risk of PSTS (P<0.05).

Conclusion : In conclusion, our study found that female gender, older age, lower preoperative T1 slope, and multi-level surgery were associated with a higher incidence of prevertebral soft tissue swelling following anterior cervical discectomy and fusion. These findings can potentially aid in predicting the occurrence of post-operative prevertebral soft tissue swelling, which may lead to airway obstruction.