24. Lateral decubitus single position circumferential fusion (ALIF & PSF) improves perioperative outcomes compared to traditional anterior-posterior fusion

Abstract

<h3>BACKGROUND CONTEXT</h3> Lateral decubitus single position anterior-posterior (AP) fusion utilizing anterior lumbar interbody fusion and percutaneous posterior fixation (SPS) is a novel, Minimally Invasive Surgical technique. Single position AP fusion with anterior or lateral interbodies has been shown to be a safe, effective technique to treat of lumbar degenerative disease. This study directly compares perioperative outcomes of SPS vs FLIP for degenerative pathologies. <h3>PURPOSE</h3> To determine if SPS with lateral ALIF (LALIF) improves perioperative outcomes compared to FLIP patients. <h3>STUDY DESIGN/SETTING</h3> Multicenter retrospective cohort study. <h3>PATIENT SAMPLE</h3> A total of 321 patients undergoing primary AP fusions with ALIF and bilateral percutaneous pedicle screw fixation at 5 institutions from 2015 to 2020. <h3>OUTCOME MEASURES</h3> Levels fused, inclusion of L4-L5, L5-S1, radiation dosage, operative time, estimated blood loss (EBL), length of stay (LOS), perioperative complications and radiographic outcomes. <h3>METHODS</h3> Retrospective analysis of primary ALIFs with bilateral percutaneous pedicle screw fixation between L4-S1 over 5 years at 5 institutions. Patients were grouped as FLIP or SPS. Outcome measures: levels fused, inclusion of L4-L5, L5-S1, radiation dosage, operative time, estimated blood loss (EBL), length of stay (LOS), perioperative complications. Radiographic analysis included lumbar lordosis (LL), pelvic incidence (PI), and PI-LL mismatch. Measures were compared using independent samples t-tests and chi-squared analyses, significance set at p<0.05. Cohorts were propensity matched (PSM) for levels fused. <h3>RESULTS</h3> A total of 321 patients: 124 SPS, 197 Flip were identified. PSM was performed due to differences between groups in levels fused, and proportion involving L4-5, yielding 248 patients: 124 SPS, 124 FLIP. The SPS cohort demonstrated significantly reduced OpTime (132.95±77.45 vs 261.79±91.65 min; p<0.001), EBL (120.44±217.08 vs 224.29±243.99 mL; p<0.001), LOS (2.07±1.26 vs 3.47±1.40 days; p<0.001), and rate of perioperative ileus (0.00% vs 6.45%; p=0.005). Radiation dose (39.79±31.66 vs 37.54±35.85 mGy; p=0.719) and perioperative complications including vascular injury (1.61% vs 1.61%; p=1.000), retrograde ejaculation (0.00% vs 0.81%, p=0.328), abdominal wall (0.81% vs 2.42%; p=0.338), neuropraxia (1.61% vs 0.81%; p=0.532), persistent motor deficit (0.00% vs 1.61%; p=0.166), wound complications (1.61% vs 1.61%; p=1.000), or VTE (0.81% vs 0.81%; p=0.972) were similar. No difference was seen in 90-day return to OR. Similar results were noted in subanalyses of single-level L4-L5 or L5-S1 fusions. On radiographic analysis the SPS cohort had greater changes in LL (4.22±11.14 vs 0.43±8.07 deg; p=0.005) and PI-LL mismatch (-4.78±8.77 vs -0.39±7.51 deg; p=0.002). <h3>CONCLUSIONS</h3> Single position lateral ALIF with percutaneous posterior fixation improves operative efficiency, EBL, LOS, rate of ileus and maintains safety compared to supine ALIF with prone percutaneous pedicle screws between L4-S1. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.