Joshua Lee

Biportal endoscopic (BE) spine surgery has gained increasing attention as a minimally invasive alternative to conventional spinal procedures, yet the distribution of procedural applications and anatomic targets within influential BE-specific publications has not been clearly synthesized. This study aimed to synthesize influential publications on BE spine surgery to describe the evolution of procedural applications, anatomic focus, and clinically relevant themes reflected in the literature. A comprehensive search of the Web of Science database was performed using terms related to biportal and multiportal endoscopic spine techniques. Influential articles were identified using citation frequency as a screening criterion, and relevant study characteristics, including publication year, authorship, institutional affiliation, geographic region, journal, and spinal region addressed, were extracted. Full-text screening confirmed inclusion of true biportal endoscopic spinal procedures and categorized the anatomical region and surgical technique addressed. Publications spanned 1997 to 2023, with a marked increase after 2018 and peak productivity in 2022. Influential publications were most frequently published in World Neurosurgery, with substantial contributions originating from South Korea, including work by Dae-Jung Choi. Most studies focused on lumbar procedures, primarily decompression techniques and transforaminal lumbar interbody fusion. Overall, this review highlights the rapid clinical growth of BE spine surgery, with influential literature emphasizing lumbar applications and underscoring the need for further research on outcomes, learning curves, and broader international adoption.

Systematic review and meta-analysis. To perform a comprehensive meta-analysis comparing clinical outcomes of uniportal versus biportal endoscopic spine surgery across decompression procedures in patients with lumbar degenerative disease (LDD). Uniportal endoscopic spine surgery has been a widely adopted minimally invasive technique, whereas biportal endoscopy has recently emerged as a promising alternative with potential advantages in surgical outcomes. A systematic review and meta-analysis of comparative studies was conducted in accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. PubMed, Embase, and Scopus databases were searched to identify relevant studies. Eleven studies encompassing 374 uniportal and 368 biportal patients were included. Outcomes analyzed were Oswestry Disability Index (ODI), Visual Analog Scale (VAS) scores for back and leg pain, complication rates, operative time, and length of hospital stay. Biportal endoscopic surgery was associated with a significantly lower ODI at 1-3 months and at final follow-up compared with uniportal surgery. However, uniportal discectomy demonstrated significantly shorter operative time and length of hospital stay than biportal discectomy. No significant differences were observed between approaches in terms of VAS scores, complication rates, or ODI at other time points. Both uniportal and biportal endoscopic spine surgeries yield comparable postoperative outcomes in LDD. Although biportal surgery showed a modest advantage in ODI improvement, it did not reach the minimal clinically important difference. Uniportal surgery demonstrated greater efficiency in terms of operative time and recovery, particularly for discectomy procedures.

Background: In spine surgery, biportal endoscopy (BE) is a minimally invasive approach for addressing a range of degenerative lumbar pathologies, including degenerative lumbar spondylolisthesis. The biportal technique benefits from the separation of the endoscopic viewing portal and the working portal for surgical tools, which facilitates an expanded visual field and greater operative flexibility ^1–3 . BE enables both decompression and transforaminal lumbar interbody fusion (TLIF) within a single procedure ⁴ . Furthermore, integrating stereotactic navigation with BE enhances the precision of pedicle screw placement, decompression, intervertebral disc removal, end-plate preparation, and navigated cage insertion. ^5,6 Description: After positioning the patient prone on a radiolucent table, the surgical field is prepared and draped in a sterile fashion. A reference pin is inserted into the iliac crest to facilitate stereotactic navigation. With use of this navigation, 2 separate 1.5 to 2-cm stab incisions are made just lateral to the cranial and caudal pedicles. The pedicles are probed and tapped in order to allow later pedicle screw fixation. Two additional skin incisions are made on the contralateral side, and percutaneous pedicle screw fixation is performed. A 30° arthroscope is introduced through the cranial incision, and a working portal is established through the caudal incision with use of a semitubular retractor. Irrigation is performed, typically set at 30 mmHg. Radiofrequency ablation is utilized to create a working space and to detach the paraspinal muscles from the underlying lamina, extending caudally into the interlaminar space and laterally to remove the facet joint capsule. Ipsilateral laminotomy or laminectomy is performed with a standard arthroscopic shaver and burr until the cranial insertion of the ligamentum flavum is visualized. Contralateral decompression is achieved by removing the ventral portion of the lamina above the ligamentum flavum, after which the ligamentum flavum is detached and removed. The ipsilateral facet joint is then removed with use of a burr and Kerrison rongeurs until the exiting nerve root is visualized and protected. An anulotomy is performed to access the disc space. End-plate preparation is conducted with use of stereotactic navigation and direct visualization through the endoscope. After trialing, an expandable cage is placed under direct visualization and navigation guidance. The endoscope is utilized to confirm the proper placement of the cage and to coagulate any epidural bleeding. Ipsilateral pedicle screws are placed with use of navigation, and rods are introduced under the fascia. Set screws are applied, and fluoroscopic images are obtained to verify the correct placement of implants. Alternatives: Surgical alternatives for degenerative lumbar spondylolisthesis include both open and tubular decompression, with or without fusion. Potential fusion techniques comprise open posterolateral fusion, open TLIF, microscopic tubular TLIF, anterior lumbar interbody fusion, and lateral lumbar interbody fusion. Rationale: BE TLIF is a minimally invasive procedure that limits osseous and soft-tissue damage and reduces postoperative pain and length of hospital stay compared with traditional open TLIF ^7–9 . Multiple studies have demonstrated similar fusion rates with improved early visual analogue pain and Short Form-36 scores and decreased estimated blood loss for BE TLIF compared with microscopic tubular TLIF ^10–12 . From a technical perspective, BE allows ultra-high magnification, which can assist with adequately decompressing the neural structures and providing direct visualization of end-plate preparation. BE also provides better ergonomics during surgery, as the surgeon is able to stand in a relaxed posture with the head upright and looking straight forward. Expected Outcomes: Long-term outcomes are similar between BE TLIF and microscopic tubular TLIF. However, Luan et al. reported that BE TLIF for lumbar degenerative diseases had the advantages of less intraoperative blood loss, less early postoperative low-back and leg pain, shorter length of hospital stay, and faster early functional recovery ¹³ . Important Tips: Gain experience with >50 biportal endoscopic decompression surgeries. Ensure proficiency in managing potential complications such as dural tears and postoperative epidural hematomas before starting TLIF surgery. Understand the stereotactic navigation systems to recognize and address discrepancies between on-screen guidance and actual cage insertion. Acronyms and Abbreviations: BE-TLIF = biportal endoscopic transforaminal lumbar interbody fusion MT-TLIF = microtubular transforaminal lumbar interbody fusion PSIS = posterior superior iliac spine SAP = superior articular process RFA = radiofrequency ablation