416 Endoscopic Lateral Lumbar Interbody Fusion: Operative Technique and Functional Outcomes

INTRODUCTION: Lateral lumbar interbody fusion (LLIF) is a common approach to lumbar fusion in cases of degenerative lumbar disease, however complications associated with psoas and lumbar plexus injury sometimes arise. The endoscopic modification presented here diminishes the requirement for sustained muscle retraction, minimizing complication risk while allowing for adequate decompression in select cases. METHODS: Endoscopic LLIF (ELLIF) was performed in 30 patients in a single center from 2019 to 2024. Surgeries were performed in the prone position (26) and transiliac (4) under general anesthesia with neurophysiological monitoring. Discectomy, endplate preparation, and iliac crest harvesting were performed through a working channel endoscope. Introduction of an interbody cage was performed over a nitinol blunt-tip wire. No expandable blade retractors were required. RESULTS: Thirty patients (15 male) with an average age of 58.5 underwent ELLIF. Every patient was diagnosed with instability and mechanical lumbar pain, and 22 presented with radicular pain. A total of seven minor complications were present in four patients postoperatively. Two patients experienced radicular pain postoperatively, compared to 22 patients prior to surgery. There were no cases of infection, cage explantation, revision surgery, or paresis . These patients experienced excellent functional recovery, with an average ODI reduction of 55% at one month (moderate disability), and 87% at one year (mild disability). CONCLUSIONS: A minimally invasive modification to the LLIF procedure is presented that offers favorable functional outcomes and several potential advantages due to application of endoscopic techniques: reduced muscle retraction, smaller incision, and the opportunity to perform both indirect decompression and endoscopically visualized discectomy in the same fusion procedure.