Outpatient Versus Inpatient Anterior Lumbar Spine Surgery: A Multisite, Comparative Analysis of Patient Safety Measures

Background: The frequency and complexity of spinal surgery performed in an ambulatory surgery center (ASC) is increasing. However, safety and efficacy data of most spinal procedures adapted to the ASC are sparse and have focused on anterior cervical surgery. The purpose of this study was to compare the 90-day complication and readmission rates of anterior lumbar spine surgery performed in an ASC or inpatient setting. Methods: We performed a retrospective comparative analysis of 226 consecutive anterior lumbar surgeries (283 levels treated) completed in an ASC (n = 124) or in an inpatient tertiary care hospital (n = 102) over a 3-year period. These included anterior lumbar interbody fusion (ALIF), artificial disc replacement (ADR), and hybrids. Patients undergoing simultaneous or staged posterior procedures within 3 months were excluded. Patient demographics and surgical parameters between the two surgical settings were compared. Ninety-day medical complications and readmission rates were assessed. One-way analysis of variance and Chi-square analysis were used. A P value of less than .05 was considered statistically significant. Results: The two study groups had similar baseline characteristics. While there was a trend toward fewer complications, reoperations, and readmissions for the ASC cohort, the differences were not statistically significant. There were 7 intraoperative complications (5.6% minor vascular injury) in the inpatient cohort and 0 in the ASC cohort. The overall 90-day postoperative complication rate was 5.6% for the inpatient cohort and 0.9% for the ASC cohort. The 90-day readmission rate was 1.9% in the ASC cohort and 1.6% in the inpatient cohort. The 90-day reoperation rate was 0.8% for the inpatient cohort and 0% in the ASC cohort. The average hospital stay was 2.3 +/- 1.5 days for the inpatient cohort. Conclusion: The 90-day readmission rates were lower for outpatients than for inpatients, while the complication and reoperation rates were similar. Our results demonstrate that anterior lumbar procedures, including single-level and multilevel ALIF, ADR, and hybrid procedures, can be performed safely in an ASC. This has significant cost savings implications for the ASC setting.