Management of Lumbar Foraminal Stenosis Using Unilateral Biportal Endoscopy Versus Conventional Open Spine Surgery

Lumbar foraminal stenosis decompression will be done using two different techniques:

1. Conventional Open Lumbar fusion By laminectomy and facetectomy and fixation with screws and rods ± interbody cage
2. Minimally invasive (Unilateral Biportal Endoscopy) Basic spine surgery instruments, 0° and 30° angled 4-mm diameter endoscopes commonly used in joint arthroscopic surgery, a radiofrequency catheter, Arthroscopic burr, and a shaver.

Surgical approach to the foraminal area Two portals are created to perform this surgery. Water is infused through the endoscope through the viewing portal, and the working portal had an additional purpose as a portal for water outflow. The proximal and distal portals are created 2 cm lateral from the pedicle level on the C-arm anteroposterior image. Each incision for the portals is 0.8 cm in length, which is adequate for instrument and endoscope insertion. For the left side foramen, the proximal and distal portals are used as the viewing and working portals, respectively, and vice versa for the right foramen. After the endoscope insertion through the viewing portal, we secure a space for the lower transverse process around the lateral surface of the facet joint. A radiofrequency catheter or a shaver is used to secure the space, and a radiofrequency catheter is used to control active bleeding.

Decompression of foraminal stenosis After a sufficient working space is obtained, the cranial 50% of the superior articular process of the thickened facet joint is removed using an arthroscopic burr or an osteotome. After removing the superior articular process, the ligamentum flavum around the foramen is removed using a curette and a Kerrison punch. After completion of flavectomy, nerve root and epidural fat are identified. If herniated disc material is found preoperatively, additional discectomy is performed usually from the axilla of the root. Surgery is confirmed to be completed after achieving an amount of free space concordant with the diameter of the nerve root in the foraminal zone, and then a drain tube is inserted.