LAUSR

BACKGROUND Outpatient spine surgery has recently been increasingly employed due to its perceived cost benefit and its ability to offset volume from the inpatient setting. However, thirty-day outcomes of outpatient posterior lumbar fusion (PLF) for low-risk patients have not been extensively studied. OBJECTIVE To assess the 30-day outcomes of outpatient PLF surgery among low-risk patients using a national surgical quality registry. METHODS For the present study, we queried the American College of Surgeons National Surgical Quality Improvement Program (ACS - NSQIP) for patients undergoing a PLF between 2009 and 2016. Only patients with an ASA grade of 1-2 were included. Thirty-day outcomes including any-complication, readmissions and reoperations were studied using multivariable logistic regression after adjusting for an array of patient specific factors. RESULTS A total of 29,830 cases were identified of which, 3.4% (n=1,016) were performed outpatient while 96.6% (n=28,814) were performed inpatient. After adjusting for an array of patient specific factors, we did not find any significant association between the procedure setting and complication rate (OR=0.8, 95% CI: 0.6-1.1, p=0.15) or 30-day readmission rate (OR 0.9, 95% CI 0.6-1.4, p=0.76). Patients undergoing an outpatient PLF were more likely to have a 30-day reoperation (OR 1.6, 95% CI 1.1-2.4, p=0.02). CONCLUSION Our results demonstrate that 30-day outcomes of patients undergoing an outpatient PLF may be comparable to those undergoing the procedure in an inpatient setting. However, outpatient surgery may be associated with a higher overall reoperation rate.