Biportal Endoscopic Excision of Facetal Cyst in the Far Lateral Region of L5S1: 2-Dimensional Operative Video.

Unilateral biportal endoscopy (UBE) is a recently introduced technique that utilizes 2 portals, one for endoscopy and one as a working portal, in contrast to full endoscopy, which utilizes a single portal. The advantages are a favorable learning curve and free mobility of instruments in the operative field. UBE is successful in addressing cervical and lumbar disc herniations, lumbar stenosis, and foraminal/extraforaminal pathologies, such as herniations and foraminal stenosis. However, there is no report of UBE for a far-lateral L5S1 facet cyst. The patient was an 85-yr-old female with a left lower limb radicular pain with magnetic resonance imaging evidence of the facet cyst compressing the L5 nerve root. Conventional treatment of such a condition would either be an L5S1 fusion procedure or a standalone decompression via the Wiltse paramedian approach. Because the patient had no instability, we decided to do a standalone decompression using the UBE technique. The UBE technique has the advantages of any minimal access procedure, including small incisions, minimal tissue dissection, good magnification, and preservation of anatomic structures. A written informed consent was obtained from the patient before the procedure. The procedure was done under general anesthesia using a 30° endoscope, a radiofrequency probe, and standard lumbar spine surgery instruments. The initial landing point of the endoscope and instruments is via triangulation at the lateral border of the isthmus of L5. The postoperative clinical and radiological outcomes were satisfactory (VAS Back and Leg, 0; Oswestry disability index, 15 at 3 mo).