Unilateral bi-portal endoscopic spine surgery (UBE) for the treatment of lumbar spinal diseases has achieved favorable results. In a systematic review, Lin et al., summarized the technical nuances, surgical outcomes, and complications of UBE.
A systematic review of the literature published up to June 2018 was performed. Published studies related to UBE were identified through searching the PubMed database. The outcomes measured included operative time, hospital stay, complications, visual analogue scale (VAS), Oswestry disability index (ODI), and the Macnab criteria.
A total of 556 patients and 679 levels were collected from the selected 11 studies. The mean follow-up was 15.2 months, the mean operative time was 81.3 minutes, and the mean length of hospital stay was 4.4 days. The mean overall complication rate was 6.7% (ranging from 0% to 13.8%). The mean VAS score for leg pain decreased from preoperative 7.9 to 1.9 at final follow-up visit and the mean VAS score for back pain decreased from 5.7 to 1.8. The mean ODI significantly improved from preoperative 63.7 to 18.6 at the final follow-up. The average satisfied outcome (excellent/good; based on Macnab criteria) was 84.3% (range, 75.35-95%). There were similar results between UBE for the treatment of lumbar disc herniation and stenosis, including operative time, length of hospital stay, complications, and satisfaction rate.
Although the existing studies are limited to small size cohorts and short-term follow-up, based on the given preliminary results and experiences of current studies, UBE may be a feasible option for lumbar spinal surgery 1).
In 2016 Hwa Eum et al., performed a unilateral laminotomy with bilateral foraminotomy 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 percutaneous biportal endoscopic decompression (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.
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.
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 2)
The stenosing foramen of L5-S1 by several degenerative diseases is one of the challenging areas on surgical approaching because of the deeper depth and steep slope in the lumbosacral junction. The floating view using unilateral biportal endoscopic spine surgery rather than docking into the Kambin's zone can make the foraminal structures seen panoramically and permit dynamic handling of various instruments without destroying the facet joint and causing iatrogenic instability. Fine discrimination of structural margins in helps of the higher magnification and gentle manipulation of neural structures just as in open spine surgery could be guaranteed using floating technique from the target structures. Selective decompression with preserving innocent structures including facet joints could relieve foraminal lesions at the L5-S1 and decrease the necessity of fusion surgery caused by wider decompression and iatrogenic instability 3).
Choi et al., provided an introduction of this technique followed by a description of the surgical anatomy with discussion on its indications and advantages. In particular, tricks to avoid complications are also presented.
Effective circumferential and focal decompression were achieved in most cases without damage to the spinal structural integrity with preservation of muscular and ligamentous attachments. The biportal endoscopic spinal surgery (BESS) may be safely used as an alternative minimally invasive procedure for lumbar spinal stenosis 4).
Biportal endoscopic spine surgery (BESS) with addressing on 2–3 cm apart from the pedicle could approach the L5–S1 without disturbing by the alar wing and freely handling of a scope with various angles in floating technique 5). Safe manipulation of neural structures could be guaranteed in helps of the higher magnification and very closed proximity to the lesions. Friendly handling of various instruments used in open spine surgery could make the performances comfort and learning curve shorter.