Minimally invasive spinal surgery in particular lumbar endoscopic unilateral laminotomy with bilateral decompression becomes popular as it can be performed with regional anesthesia, soft tissue damages are minimized as endoscopic visualization and instruments can be brought close to operating area bypassing much of the intervening soft tissues for sufficient spinal decompression with ligamentum flavum resection despite less bony resection compared to open surgery. Overall, when well executed, it preserves spinal stability. Outside-in technique of decompression is also known as over the top decompression in minimally invasive literature. It involves maintaining deep layer of ligamentum flavum integrity till satisfactory bony decompression is achieved. Deep layer of ligamentum flavum is removed as final step of decompression. Preservation of the deep layer of ligamentum flavum protects the neural elements, allowing drills and sharp equipment to be used safely to perform bony decompression.In this study, we demonstrate the technical details of outside-in approach lumbar endoscopic unilateral laminotomy with bilateral decompression (LE-ULBD). LE-ULBD Outside-in Technique is an effective and safe procedure in relieving lumbar spinal stenosis with favorable results with a follow-up for more than 1 year.
Keywords: Degenerative spine; Endoscopic spine surgery; Interlaminar spinal endoscopy; Lumbar endoscopic unilateral laminotomy; Minimally invasive spine surgery; Spinal stenosis.