40. Postoperative outcomes in cervical fusion for Ehlers-Danlos syndrome: lower nonunion but higher dysphagia and CSF leak rates

Abstract

BACKGROUND CONTEXT

Ehlers-Danlos syndrome (EDS) is a genetic connective tissue disorder that manifests as joint hypermobility, skin hyperelasticity, and vascular fragility. This systemic pathology may affect surgical outcomes, most notably cervical fusions, by potentially increasing the risks of complications namely nonunion, dysphagia and cerebrospinal fluid (CSF) leaks postoperatively. Cervical fusions are a common procedure to address degenerative spine pathologies; however, there is minimal data on postoperative outcomes in EDS patients.

PURPOSE

This study investigates the rates of nonunion, dysphagia, and CSF leak in EDS patients and non-EDS patients who underwent cervical fusion procedures.

STUDY DESIGN/SETTING

N/A

PATIENT SAMPLE

N/A

OUTCOME MEASURES

The outcomes measured were the possibility of nonunion, dysphagia, and CSF between EHS and non-EHS patients in percentages associated with the risk difference and p-value.

METHODS

Using TriNetX, a retrospective cohort study was performed to study the rates of postoperative nonunion, dysphagia, and CSF leak. Patients aged 18-65 were categorized into EDS (ICD-10: Q79.6, n=527) and non-EDS (n=73,130) cohorts. Those with diabetes, tobacco use, cancer, chronic steroid use, and other connective tissue disorders were excluded. ICD-10 codes for nonunion, dysphagia, and CSF leaks (M96.0, R13.10, and G96.0, respectively) were utilized as data collection parameters. ICD-10 codes must also be added to the patient’s encounter within 3 years postoperative to be included in the study.

RESULTS

The nonunion rate is notably lower in EDS patients (11.195%) compared to non-EDS patients (16.663%) (p=0.0008). Additionally, the occurrence of dysphagia was seen to be higher in EDS patients (11.006%) when compared to non-EDS patients (7.201%) (p<0.0008). Finally, CSF leak in EDS patients (3.605%) is higher than non-EDS patients (0.655%) (p<0.0001).

CONCLUSIONS

EDS patients who underwent cervical fusion procedures had notably lower nonunion rates than non-EDS patients, regardless of the abnormalities within their connective tissues. This is potentially a result of external influences akin to surgeon selection bias, innovative fixation approaches, or innate differences in bone metabolism associated with joint hypermobility. In contrast, EDS patients exhibited significantly higher rates of dysphagia and CSF leaks, emphasizing the impact EDS pathology has on surgical outcomes. Increased dysphagia in EDS patients may be connected to their autonomic dysfunction, as their joint hypermobility tends to manifest vagus nerve constriction, resulting in swallowing and gastrointestinal motility deficits. Interestingly, dysphagia rates among EDS patients appear comparable between cervical and lumbar fusions, despite dysphagia traditionally being more associated with cervical fusion procedures. This suggests a systemic factor potentially linked to autonomic dysfunction, rather than a mechanical consequence of cervical surgery. EDS patients may have an increased likelihood of CSF leaks due to dura mater fragility caused by defective collagen synthesis. A weakness of this study is the ICD-10 limitations in distinguishing between the percentage of patients with anterior versus posterior cervical fusion. The stratification of different surgical approaches in EDS can be further studied. Based on the findings discussed, there is a benefit to providing special considerations to surgical approaches, preoperative counseling, and postoperative monitoring for EDS patients undergoing cervical fusions to optimize outcomes and minimize complications.

FDA Device/Drug Status

This abstract does not discuss or include any applicable devices or drugs.