1523. Complications in non-instrumented posterior cervical spine surgeries performed in the sitting and prone positions

Authors: Benjamin T. Himes, MD; Arnoley Abcejo, MD; Panagiotis Kerezoudis, MD; Katherine Trelstad Andrist; Patrick Maloney, MD; Mohamad Bydon, MD (Rochester, MN)

Introduction: The sitting position allows for improved visualization and venous drainage, particularly in cases involving the posterior fossa and cervical spine. However, perceived risks of the sitting position procedures have limited its use. We examined complications in posterior cervical spine cases performed in the sitting and prone positions. Methods: Our institution’s operative case log was reviewed. Non-instrumented posterior cervical spine cases performed in the sitting and prone positions between 2000 and 2016 were included. Demographic data, operative time, anesthesia time, fluids given, blood loss, return to the operating room, and transfer to the intensive care unit (ICU) postoperatively were recorded. Univariate analysis was performed using two-tailed t-tests for all variables. Multivariate logistic regression was performed for development of complications, readmission, and reoperation within 30 days of surgery. Results: 869 sitting and 373 prone cases were identified. Demographic data, including median age, gender, BMI, ASA class, and Charlson Comorbidity Scale, did not differ significantly between the two groups. Sitting cases were associated with longer operative times (256 vs. 217 minutes, p<0.001). Prone cases were associated with more instances of postoperative apnea or hypoventilation in the post-anesthesia recovery unit (PACU), as well as a higher incidence of unplanned ICU admission following surgery (54.5% vs. 3.57% p<0.001). However, the rate of postoperative ICU stay was higher overall in sitting cases (16.1% vs. 2.95% p<0.001). Rates of 30-day return to the operating room (OR 0.69, 95% CI 0.39-1.21, p=0.19) or readmission (OR 0.59, 95% CI 0.33-1.05, p=0.07) did not differ significantly between the groups on multivariate analysis, however the sitting position was associated with an overall lower complication rate (OR 0.32, 95% CI 0.20-0.52, p< .001). Conclusion: Posterior non-instrumented cervical spine surgery can be performed safely in the sitting position, with no increase in risk of postoperative neurologic complications compared to prone cases.