Lumbar Endoscopic Unilateral Laminotomy for Bilateral Decompression Outside-In Approach: A Proctorship Guideline With 12 Steps of Effectiveness and Safety

Abstract

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.

Clinical Results And Review of Techniques of Lumbar Endoscopic Unilateral Laminotomy With Bilateral Decompression (LE-ULBD) for Lumbar Stenosis

“…The concept of LEULBD is not new. Recently, Lim et al and Kim et al coined the terms, inside out (under the ligamentum flavum decompression approach) 8) and outside-in (over the top decompression) 4) approach to describe the endoscopic handling of ligamentum flavum. With the under the ligamentum flavum decompression approach focus on usage of endoscopic Kerisson Rongeurs removing the ligamentum flavum with the lamina bone together, entering the epidural space early in the procedure.…”

“…The evolution of endoscopic spine surgery (ESS) leads to an increasing trend of more Lumbar Endoscopic Unilateral Laminotomy For Bilateral Decompression (LEULBD) being performed for spinal stenosis and related conditions. There are several technical approaches described for LEULBD to achieve the same target of spinal decompression 2,4,9,10) . The key differences in the described techniques can be divided into docking and identification of key bony landmark, approach to lamina, method of removal of ipsilateral and contralateral ligamentum flavum.…”

“…While there are differences in details, there are benefits and risks inherent to each of the various described techniques. In this technical review, we describe the key differences in the over the top decompression and under the ligamentum flavum decompression approach of LEULBD, which recently coined as Outside-in by Kim et al 4) and Inside-out by Lim et al 8) A retrospective analysis of clinical outcome of our cohort of LEULBD patient was performed.…”

Overview of Tips in Overcoming Learning Curve in Uniportal and Biportal Endoscopic Spine Surgery

“…The instruments in transforaminal approach are correspondingly longer than those used in interlaminar discectomy endoscope. Wider working channel dimensions endoscope and its correspondingly larger dimension endoscopic instruments are provided for lumbar endoscopic unilateral laminotomy with bilateral decompression (LEULBD) designed to use for stenosis cases 23,37) . Biportal ESS on the other hand uses mostly open spine general equipment and orthopaedic arthroscope.…”

“…In LEULBD, the docking point of spinolaminar junction and laminofacet junction (V-point) are the commonly described anatomical landmarks. The endoscope used in interlaminar approaches is comparatively lower angle of 10-20 degrees 23) . In higher lumbar levels, the interlaminar space is narrow and it may not be compatible to relatively large uniportal endoscope and retractor dimensions make it difficult to land on the medial aspect of the laminofacet junction (V-point).…”