OBJECTIVE: The use of conventional uniportal spinal endoscopic decompression surgery for lumbar spinal stenosis can be limited by technical difficulties and a restricted field of vision. The purpose of this study is to describe the technique for percutaneous biportal endoscopic decompression (PBED) for lumbar spinal stenosis and analysis of clinical postoperative results. METHODS: The authors performed a unilateral laminotomy with bilateral foraminal decompression using a unilateral biportal endoscopic system in patients with single-level lumbar stenosis. The authors enrolled only patients who underwent follow-up for longer than 12 months after PBED. Fifty-eight patients were enrolled in this study. This approach was based on 2 portals: one portal was used for continuous irrigation and endoscopic viewing and the other portal was used to manipulate the instruments used in the decompression procedures. Clinical parameters such as the Oswestry Disability Index (ODI), Macnab criteria, and postoperative complications were analyzed. RESULTS: Neural decompression was effectively performed in all enrolled patients. The mean ODI was significantly lower after PBED. Of 58 patients, 47 (81.0%) had a good or excellent result according to the Macnab criteria. Postoperative ODI and visual analog scale scores were significantly improved compared with preoperative values. CONCLUSIONS: From a surgical point of view, percutaneous biportal endoscopy is very similar to microscopic spinal surgery, permitting good visualization of the contralateral sublaminar and medial foraminal areas. The authors suggest that the PBED, which is a minimally invasive procedure, is an alternative treatment option for degenerative lumbar stenosis.

OBJECTIVE: Minimally invasive spine surgery can minimize damage to normal anatomical structures. Recently, fully endoscopic spine surgeries have been attempted for lumbar fusion surgery. In this study, the authors performed a percutaneous unilateral biportal endoscopic (UBE) technique as a minimally invasive surgery for lumbar fusion. The purpose of this study is to present the UBE technique of fully endoscopic lumbar interbody fusion (LIF) and to analyze the clinical results. METHODS: Patients who were to undergo single-level fusion surgery from L3–4 to L5–S1 were enrolled. Two channels (endoscopic portal and working portal) were used for endoscopic lumbar fusion surgery. All patients underwent follow-up for more than 12 months. Demographic characteristics, diagnosis, operative time, and estimated blood loss were evaluated. MRI was performed on postoperative Day 2. Clinical evaluations (visual analog scale [VAS] for the leg and Oswestry Disability Index [ODI] scores) were performed preoperatively and during the follow-up period. RESULTS: A total of 69 patients (24 men and 45 women) were enrolled in this study. The mean follow-up period was 13.5 months. Postoperative MRI revealed optimal direct neural decompression after fully endoscopic fusion surgery. VAS and ODI scores significantly improved after the surgery. There was no postoperative neurological deterioration. CONCLUSIONS: Fully endoscopic LIF using the UBE technique may represent an alternative minimally invasive LIF surgery for the treatment of degenerative lumbar disease. Long-term follow-up and larger clinical studies are needed to validate the clinical and radiological results of this surgery.

OBJECTIVE: Recently, minimally invasive unilateral laminotomy with bilateral decompression (ULBD) has been performed for lumbar stenosis using endoscopic approaches. The object of this retrospective study was to compare the clinical and radiological outcomes of three types of minimally invasive decompressive surgery: microsurgery, percutaneous uniportal endoscopic surgery, and percutaneous biportal endoscopic surgery. METHODS: In the period from March 2016 to December 2017, minimally invasive ULBD was performed using microscopy, a uniportal endoscopic approach, or a biportal endoscopic approach to treat lumbar canal stenosis. Patients were classified into three groups based on the surgery they had undergone. The angle of medial facetectomy area and postoperative dural expansion were measured using MR images. The visual analog scale (VAS) score for leg and back pain, Oswestry Disability Index (ODI), operation time, and complications were assessed. Clinical and radiological parameters were compared among the three groups. RESULTS: There were 33 patients in the microscopy group, 37 in the biportal endoscopy group, and 27 in the uniportal endoscopy group. Preoperatively stenotic dural areas were significantly expanded in each of the three groups after surgery (p < 0.05). Mean dural expansion in the uniportal endoscopy group was significantly lower than that in the microscopy or biportal endoscopy group (p < 0.05). The mean angle of the facetectomy in the biportal endoscopic group was significantly lower than that in the microscopic group or uniportal endoscopic group (p < 0.05). On the 1st day after surgery, the VAS score for back pain was significantly higher in the microscopic group than in the uniportal or biportal endoscopic group (p < 0.05). However, there were no significant differences in the VAS score for back pain, VAS score for leg pain, or ODI at the final follow-up among the three groups (p > 0.05). CONCLUSIONS: Although radiological results were different among the three groups of patients, postoperative clinical outcomes were significantly improved after each type of surgery. The percutaneous biportal or uniportal endoscopic approach offers the advantage of reduced immediate postoperative pain. A percutaneous uniportal or biportal endoscopic lumbar approach may be effective for the treatment of lumbar central stenosis and an alternative to conventional microsurgical decompression.