43 - Outcomes after Single-level Posterior Lumbar Interbody Fusion: Outpati...

#43 Outcomes after Single-level Posterior Lumbar Interbody Fusion: Outpatient vs Inpatient

Epidemiology/Natural History

Poster Presented by: K. Singh


A.J. Marquez-Lara (1)
S.V. Nandyala (1)
S.J. Fineberg (1)
M. Noureldin (1)
K. Singh (1)

(1) Rush University Medical Center, Orthopaedic Surgery, Chicago, IL, United States


Introduction: Posterior Lumbar Interbody Fusion (PLIF) is commonly done in patients with lumbar spine degenerative disc disease and instability. As the surgical technique and instrumentation continues to improve, PLIF surgery has become a safe and successful outpatient procedure. The purpose of this study was to analyze a population-based database to determine the differences in patient demographics, preoperative conditions and surgical outcomes between outpatient and inpatient single-level PLIFs.

Methods: The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was utilized to identify patients who underwent a single-level PLIF between 2002-2009. The resulting patient sample was divided into outpatient and inpatient surgery cohorts. Preoperative patient characteristics (demographics, co-morbidities, pre-operative lab values), surgery and hospital outcomes (e.g., operative time, length of stay (LOS), 30-day complication rates, and mortality) were compared between groups. Statistical analysis was performed with SPSS v.20 using independent t-tests and χ2-tests for continuous and categorical variables respectively. P-values ≤ 0.001 were considered statistically significant.

Results: A total of 4,038 single-level PLIFs were identified between 2002-2009, of these, 2.5% (n=102) were done in an outpatient setting. Patient demographics, including age, gender and race, as well as preoperative comorbidities and laboratory values were not different between the two groups. However, patients who underwent PLIF as outpatients were significantly younger than those who were kept as inpatients (53.25(SD13.2) vs 57.93(SD14.2), p =0.001). Intraoperative blood transfusion requirements and resident involvement were not different between groups, however surgery was on average 45.5 minutes faster in the outpatient group when compared to the inpatient group (154.4(SD116.2) vs 200.0 (SD97.2), p< 0.001). Postoperative complications and outcome data including readmission, reoperation and mortality rates did not significantly differ between groups. Interestingly, average LOS in the outpatient group was 1.95 days, as opposed to 3.88 days in the inpatient group (p< 0.001).

Conclusion: Outpatient single-level PLIF is a safe and successful surgical procedure regardless of patient preoperative conditions. As expected, intraoperative time was significantly reduced in the outpatient group, which likely decreased anesthesia load, favoring faster recovery after surgery. Our data demonstrated an average LOS in the outpatient group of 1.95 days, which may represent a subset of planned outpatient cases that eventually required admission. Clearly, prolonged admission beyond the normal 23 hours is common for single level PLIFs performed in an outpatient environment. Further studies should aim to clarify the risk factors and post-operative events associated with a hospital admission following a planned outpatient PLIF.