Biportal Endoscopic Posterior Thoracic Laminectomy for Thoracic Spondylotic Myelopathy Caused by Ossification of the Ligamentum Flavum: Technical Developments and Outcomes

O-arm navigation-based transforaminal unilateral biportal endoscopic discectomy for upper lumbar disc herniation: an innovative preliminary study

STUDY DESIGN

Technical case report.

PURPOSE

To present a novel navigation-assisted transforaminal unilateral biportal endoscopy (UBE) lumbar discectomy technique for managing upper lumbar disc herniation.

OVERVIEW OF LITERATURE

Upper lumbar disc herniation is significantly less common than lower lumbar disc herniation, accounting for only 1%-2% of cases. However, treatment is more challenging and is associated with worse outcomes. Anatomical differences between the upper and lower lumbar spine complicate the standard interlaminar approach using UBE, making it insufficient for complete removal of herniated discs. Integrating endoscopic spine surgery with intraoperative navigation provides three-dimensional computer-reconstructed visual data, thereby enhancing the feasibility of the technique.

METHODS

The UBE approach targeted the ventral part of the superior articular process in the transforaminal UBE setup, specifically for upper lumbar disc herniation, with an approach angle of approximately 30º on the axial plane. Intraoperative navigation was employed to improve puncture accuracy for this relatively unfamiliar surgical technique. Navigation-assisted transforaminal UBE lumbar discectomy was performed on four patients presenting with back or leg discomfort due to disc herniation at the L1-L2 or L2-L3 levels.

RESULTS

All patients experienced symptom relief and were discharged on postoperative day 2.

CONCLUSIONS

Transforaminal UBE lumbar discectomy is a viable therapeutic option for upper lumbar paracentral disc herniation, which is typically associated with poor prognosis. Integrating navigation integration into this novel approach enhances precision and safety.

The unilateral biportal endoscopy journey: proposing a 10-tier difficulty progression framework for unilateral biportal endoscopy

Unilateral biportal endoscopy (UBE) has revolutionized minimally invasive spinal surgery, offering enhanced visualization and reduced recovery times. However, the steep learning curve and technical complexity require a structured training framework. This narrative review proposes a 10-tier difficulty progression framework for UBE designed to guide novice surgeons through incremental skill acquisition. Each tier corresponds to specific procedures with escalating challenges spanning lumbar, cervical, and thoracic pathologies. The proposed framework begins with foundational lumbar procedures, such as ipsilateral recess decompression and discectomy, and advances to more intricate techniques, such as transforaminal lumbar interbody fusion. Transitioning to the cervical and thoracic regions requires mastery of earlier tiers, emphasizing precision in handling delicate anatomical structures. These challenges include achieving proficiency in mobilizing nerve roots, minimizing spinal cord manipulation, and mastering advanced decompression techniques. Evidence from learning curve analyses, including cumulative sum methodologies, underscores the importance of tailored training to reduce complications and optimize outcomes. By standardizing the progression of UBE procedures, this framework aims to enhance surgical safety, improve patient outcomes, and facilitate their widespread adoption. Future research should focus on validating this framework by using clinical trials, training feedback, and long-term patient data. Ultimately, this 10-tiered approach provides a roadmap for mastering UBE, addressing the growing demand for minimally invasive spinal surgery with precision and confidence.

Open posterior approach versus endoscopic approach for thoracic ligamentum flavum ossification: a systematic review and meta-analysis

BACKGROUND

Thoracic ossification of the ligamentum flavum (TOLF), a rare condition more prevalent in East Asia, is managed through open and endoscopic surgical approaches. Determining the superior surgical option remains unclear. This study assesses the safety and clinical outcomes associated with these approaches in TOLF patients.

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a systematic literature search up to August 5, 2023, across PubMed, Scopus, EMBASE, Web of Science, Cochrane, and ClinicalTrials.gov. We included randomized controlled trials and cohort studies reporting complication rates, mJOA (modified Japanese Orthopedic Association) scores, JOA scores, VAS (Visual Analog Scale) scores, or hospitalization duration for both open and endoscopic surgeries in TOLF patients.

RESULTS

We analyzed 37 studies encompassing 1,646 TOLF patients using a random-effects model. Our findings revealed a significant difference in complication rates (overall complication rates: 0.12; 95% CI: 0.07, 0.19; p < 0.01; I2: 69%; quality of evidence: moderate), with lower complication rates in the endoscopy group. However, no significant differences were observed in JOA scores (overall JOA: 8.35; 95% CI: 7.16, 9.54; p = 0.12; I2: 99%; quality of evidence: very low), VAS scores (overall VAS: 1.31; 95% CI: 1.03, 1.59; p = 0.35; I2: 91%; quality of evidence: very low), or hospitalization duration (hospital stay: 10.83 days; 95% CI: 6.86, 14.80; p = 0.35; I2: 91%; quality of evidence: very low) between the open and endoscopic groups.

CONCLUSIONS

This meta-analysis reports lower complication rates and improved postoperative mJOA scores for endoscopic surgery in TOLF patients compared to open surgery. It represents the first comprehensive evaluation of clinical outcomes and safety of different surgical approaches for TOLF patients. Further randomized controlled trials are essential to validate these findings.

Uniportal Full Endoscopic 270° Decompression for Thoracic 1-2 Hard Disc Herniation With Ossification of the Ligamentum Flavum

This article aims to demonstrate the uniportal full endoscopic surgery for treating complex anterior and posterior spinal pathology at the T1-2 level, offering a invasive, accessible, stable, and versatile approach to challenging anatomical situations. Uniportal full endoscopic surgery is one of the most minimally invasive spinal surgeries, utilizing slim, elongated, and compact instruments that provide access to lesions from any angle and distance. This characteristic makes the technique especially suitable for hard, such as the T1-2 level, where traditional approaches may be limited or difficult. We present the case of a 39-year-old male patient (height, 187 cm; weight, 130 kg) who developed myelopathy due to a hard disc herniation and ossification of the ligamentum flavum at the T1-2 leading to paraparesis, which was more severe on the left side. An anterior approach was challenging due to the anatomical constraints at the T1-2 level, as well as the patient's body size. A posterior access via the interlaminar approach facilitated the removal of the ossified ligamentum flavum. However, to the anterior lesion remained problematic without spinal cord retraction. Using the uniportal full endoscope, we were able to approach both anterior and posterior lesions through an incision 8 cm lateral to the midline, allowing for the treatment of the entire 270° arc of the pathology. The slim and elongated nature of the full endoscope enabled effective decompression without exerting pressure on the spinal cord, providing access from any angle and distance. This technique can be applied to a variety of cases involving difficult-to-access spinal.

Comparison of endoscopic decompression to open laminectomy in patients with thoracic ossified ligamentum flavum - a systematic review and meta-analysis

In recent years, there has been growing interest in an alternative approach for treating TOLF, such as endoscopic decompression, which minimizes the disruption of surrounding tissues. It is important to understand the advantages, disadvantages, and potential differences in outcomes associated with each approach. This comparative study aims to evaluate and contrast the effectiveness, safety, and outcomes of these two surgical techniques, open laminectomy and endoscopic decompression, in the management of thoracic OLF. The literature review was conducted on Embase, PubMed, Scopus and Google Scholar databases. After a thorough screening of all search results, 14 studies were shortlisted, from which data was extracted, and statistical analysis was done. Pooled analysis was done to ascertain the intra-operative and post-operative outcomes after surgery for TOLF. Overall, 351 patients were included in the study for evaluation. 174 patients were operated on by open laminectomy, and 177 patients were seen in the endoscopy group. Decreased operative time was seen in the endoscopic subgroup. The mean length of hospital stay of 6.6 days. Both groups showed improvement in mJOA and VAS score. The recovery rate for the reported study cohort was 66.8%, with the Endoscopic surgical approach showing a positive correlation with the mean recovery rate. The dural tear was the most common complication, with a rate of 6.6%. The mean estimated infection rate was 2.7% and postoperative CSF leak was 3.7%, with a trend of significantly higher rates in the open subgroup. Both of the groups showed improvement in functional scores, VAS scores, and cross-sectional area. However, the Endoscopic decompression group experienced reduced hospital stays, operating times, and intraoperative blood loss. The most frequent side effects were CSF leak and dural tear. A few cases showed revision and infection. None of the problems differed between the groups.

A narrative review of endoscopic spine surgery: history, indications, uses, and future directions

Background and Objective

The concept of endoscopic surgery began in the 1930s and has since undergone numerous advancements in both technology and surgical indications. Its main benefit is providing the opportunity to perform surgery while minimizing disruption to surrounding structures. The purpose of this review is to summarize the history, uses, and future directions for spine endoscopic surgery.

Methods

A review of national databases was performing using key terms "endoscopic", "spine" and "surgery" for literature from 1900 to 2023. Studies that aimed to describe the utilities of endoscopic surgeries, associated outcomes, limitations, and future directions were included. Studies that were not in English were excluded.

Key Content and Findings

This review includes a brief overview of the history of endoscopic surgery and its current two main approaches, transforaminal and interlaminar approaches. It then summarizes the main indications and utilization of endoscopic surgery in the lumbar, cervical and thoracic spine, as well as expansion in managing spine tumors, infections, and outpatient surgical cases.

Conclusions

There are many rising indications and uses for endoscopic spine surgery in nearly every aspect of the spine. Compared to conventional spine surgery, there is early evidence showing endoscopic surgery is associated with less post-operative pain, shorter hospital stays, and possibly quicker recovery times. As current trends in spine surgery move towards minimally invasive techniques, it is anticipated that the use of endoscopic surgery will continue to expand.

Biportal endoscopic cervical open-door laminoplasty to treat cervical spondylotic myelopathy

BACKGROUND

Although cervical laminoplasty is a frequently utilized surgical intervention for cervical spondylotic myelopathy, it is primarily performed using conventional open surgical techniques. We attempted the minimally invasive cervical laminoplasty using biportal endoscopic approach.

METHODS

Contralateral lamina access is facilitated by creating space through spinous process drilling, followed by lamina hinge formation. Subsequently, the incised lamina is elevated from ipsilateral aspect, and secure metal plate fixation is performed.

CONCLUSION

We successfully performed the cervical open door laminoplasty using biportal endoscopic approach. Biportal endoscopic cervical open-door laminoplasty may be a minimally invasive technique that can prevent complications related with open surgery.

Biportal endoscopic transforaminal thoracic interbody fusion for the treatment of thoracic myelopathy

BACKGROUND

Biportal endoscopic spine surgery independently controls two hands, similar to microscopic surgery, and utilizes a broader working space that is not disturbed by retractors under clear-magnified endoscopic vision. These advantages facilitate successful neural decompression and safe transforaminal interbody fusion, even in patients with thoracic spondylotic myelopathy.

METHODS

A wide laminectomy and precise total facetectomy, in conjunction with partial pediculotomy, establish a secure transforaminal space for cage insertion. Endplate preparation and cage insertion were performed without retracting the spinal cord under direct endoscopic vision.

CONCLUSION

Biportal endoscopic transforaminal thoracic interbody fusion can be a feasible technique for treating thoracic spondylotic myelopathy at the thoracolumbar junction levels.

Safety and efficacy of one-hole split endoscope technique for surgical treatment of thoracic ossification of the ligamentum flavum

Surgical intervention is typically recommended for thoracic ossification of the ligamentum flavum (TOLF). This study aimed to evaluate the efficacy and safety of a novel non-coaxial one-hole split endoscope (OSE) technique for treating TOLF. We performed OSE procedure on 13 patients with TOLF from June 2022 to July 2023. The mean operative time was 117.5 ± 15.4 min. VAS scores for lower limbs decreased from 6.5 ± 0.8 preoperative to 1.6 ± 0.4 at the last follow-up (P < 0.001). ODI scores improved from 62.4 ± 5.7 preoperative to 18.6 ± 2.2 at the last follow-up (P < 0.001), and mJOA scores increased from 5.1 ± 1.6 preoperative to 8.4 ± 1.5 at the latest follow-up (P < 0.001). All patients achieved ASIA scale grade D or E at the final follow-up, except for two patients remained residual limb numbness. None of the thirteen patients suffered from severe perioperative complications. The OSE technique proves to be a safe and effective procedure for treating TOLF or even with dura mater ossification, characterized by minimal surgical trauma, relatively smooth learning curve and flexible operation.

Future of Endoscopic Spine Surgery: Insights from Cutting-Edge Technology in the Industrial Field

In the evolving landscape of spinal surgery, technological advancements play a pivotal role in enhancing surgical outcomes and patient experiences. This paper delves into the cutting-edge technologies underpinning endoscopic spine surgery (ESS), specifically highlighting the innovations in scope cameras, RF equipment, and drills. The modern scope camera, with its capability for high-resolution imaging, offers surgeons unparalleled visualization, enabling precise interventions. Radiofrequency (RF) equipment has emerged as a crucial tool, providing efficient energy delivery for tissue modulation without significant collateral damage. Drills, with their enhanced torque and adaptability, allow for meticulous bone work, ensuring structural integrity. As minimally invasive spine surgery (MISS) becomes the standard, the integration and optimization of these technologies are paramount. This review captures the current state of these tools and anticipates their continued evolution, setting the stage for the next frontier in spinal surgery.

Complications of Endoscopic Thoracic Spine Surgery: Overview and Complication Avoidance

In endoscopic thoracic spine surgery, adaptations of thoracic surgical techniques such as full endoscopic uniportal and biportal surgical techniques have been developed. Full endoscopic uniportal surgery for thoracic disc herniation or thoracic ossified ligamentum flavum (OLF) has been performed via transforaminal and interlaminar approaches. In the case of thoracic OLF or thoracic spinal stenosis, the uniportal interlaminar approach is appropriate. The uniportal interlaminar approach has been used to treat thoracic OLF and has shown good surgical results. Thoracic OLF removal via a biportal endoscopic technique has been developed recently and is described in a few studies. Although endoscopic thoracic spine surgery has significant advantages, complications often occur with this approach. We reviewed the literature to date on the complications associated with endoscopic spine surgery in thoracic pathology. This review emphasizes how to avoid and manage complications. Based on the results of several previous studies, endoscopic thoracic spine surgery could be associated with fewer potential complications than conventional surgery. Endoscopic spine surgery has remarkable advantages; however, endoscopic thoracic surgery is technically challenging and is potentially associated with serious complications. To minimize the risk of avoidable complications, surgeons should be familiar with prevention methods and pitfalls.

Uniportal Thoracic Endoscopic Unilateral Laminotomy with Bilateral Decompression of Thoracic Ossification of Ligamentum Flavum: A Systematic Review of Current Literature

BACKGROUND

Thoracic ossification of ligamentum flavum (TOLF) is a rare disease that often results in worsening neurologic sequelae if left untreated. Although the gold standard treatment for TOLF is open posterior laminectomy, it is often accompanied by high rates of complications and perioperative morbidity. There have been studies looking into feasibility of endoscopic posterior decompression for TOLF, citing potential for lower perioperative morbidity and achieving similar functional outcomes to its open laminectomy counterparts. We provide an up-to-date systematic review of clinical outcomes after endoscopic posterior decompression for TOLF from the latest assemblage of evidence.

METHODS

A systematic review of the technique was conducted from May 2000 to May 2023. Articles were selected based on PRISMA guidelines. Eligibility of studies was independently by 2 reviewers, with disagreements resolved by a third author.

RESULTS

Nineteen primary references comprising 337 patients with TOLF who underwent endoscopic posterior decompression were included in the systematic review. Mean follow-up time across all studies ranged from 8.9 to 65.3 months. Mean age ranged from 51.2 to 63 years, with mean intraoperative blood loss ranging from 15 to 62 mL. There is significant improvement in visual analog scale (VAS) score, VAS back, VAS leg, modified Japanese Orthopaedic Association score, and Oswestry Disability Index compared with preoperative recorded values across all studies, with low rates of complications reported.

CONCLUSIONS

Endoscopic posterior spinal decompression is a safe and effective technique for treatment of TOLF, with a low rate of complications and improvement in pain and function.

Lumbar Endoscopic Unilateral Laminotomy With Bilateral Decompression Surgery in Severe Lumbar Stenosis Under Electrophysiological Monitoring-Focused on Full-Visualized Trephine/Osteotome

OBJECTIVE

Although endoscopic drill has the advantages in manipulation and hemostasis, whose low efficiency and blurred vision reduce the efficacy of lumbar endoscopic unilateral laminotomy with bilateral decompression (LE-ULBD). The present study was designed to evaluate the safety and efficacy of full-visualized trephine/osteotome in the LE-ULBD surgery for severe lumbar stenosis.

METHODS

Fifty-seven severe lumbar stenosis patients who underwent LE-ULBD between January 2020 to January 2023 were enrolled, who were divided into drill and visualized trephine groups. The medical records including demographics, operative duration, intraoperative electrophysiological findings, postoperative hospital stay or hospital stay, postoperative outcomes and complications were retrospectively reviewed and analyzed.

RESULTS

A total of 57 patients included 15 in drill and 42 in trephine group were enrolled in the study. There was significant difference in the pre- and postoperative visual analogue scale and Oswestry Disability Index scores in both groups (p < 0.05). The mean operative duration in the trephine group (101.05 ± 12.18 minutes) was shorter than that in the drill group (134.67 ± 9.68 minutes) (p < 0.05). There was no statistical difference between the 2 groups in electrophysiological monitoring, posthospital stays, postoperative outcomes and complications. Abnormal free-electromyography (EMG) were recorded in 2 (13.3%) and 5 patients (11.9%) in the drill and trephine group. Intraoperative somatosensory evoked potential changes occurred in 3 (20%) and 3 patients (7.1%) in the drill and trephine group and all patients recovered immediately when surgery ended. No serious complications and recurrence occurred in all the patients.

CONCLUSION

Full-visualized trephine/osteotome has been approved to be convenient, safe and efficient in our study, which combined with translaminar inside-out technique and EMG monitoring especially free-EMG may offer a new choice in LE-ULBD surgery for lumbar stenosis patients.