Does obesity and varying body mass index affect the clinical outcomes and safety of biportal endoscopic lumbar decompression? A comparative cohort study.

BACKGROUND: Endoscopic spine surgery has recently grown in popularity due to the potential benefits of reduced pain and faster recovery time as compared to open surgery. Biportal spinal endoscopy has been successfully applied to lumbar disc herniations and lumbar spinal stenosis. Obesity is associated with increased risk of complications in spine surgery. Few prior studies have investigated the impact of obesity and associated medical comorbidities with biportal spinal endoscopy. METHODS: This study was a prospectively collected, retrospectively analyzed comparative cohort design. Patients were divided into cohorts of normal body weight (Bone Mass Index (BMI)18.0-24.9), overweight (BMI 25.0-29.9) and obese (BMI > 30.0) as defined by the World Health Organization (WHO). Patients underwent biportal spinal endoscopy by a single surgeon at a single institution for treatment of lumbar disc herniations and lumbar spinal stenosis. Demographic data, surgical complications, and patient-reported outcomes were analyzed. Statistics were calculated amongst treatment groups using analysis of variance and chi square where appropriate. Statistical significance was determined as p < 0.05. RESULTS: Eighty-four patients were followed. 26 (30.1%) were normal BMI, 35 (41.7%) were overweight and 23 (27.4%) were obese. Patients with increasing BMI had correspondingly greater American Society of Anesthesiologist (ASA) scores. There were no significant differences in VAS Back, VAS Leg, and ODI scores, or postoperative complications among the cohorts. There were no cases of surgical site infections in the cohort. All cohorts demonstrated significant improvement up to 1 year postoperatively. CONCLUSIONS: This study demonstrates that obesity is not a risk factor for increased perioperative complications with biportal spinal endoscopy and has similar clinical outcomes and safety profile as compared to patients with normal BMI. Biportal spinal endoscopy is a promising alternative to traditional techniques to treat common lumbar pathology.

Does the use of tranexamic acid intraoperatively reduce postoperative blood loss and complications following biportal endoscopic lumbosacral decompression?

Background: Biportal endoscopic spine surgery is an effective minimally invasive technique for treating common lumbar pathologies. We aim to evaluate the impact of intraoperative tranexamic acid (TXA) use on postoperative blood loss in biportal endoscopic decompression surgery. Methods: Patients undergoing biportal endoscopic lumbar discectomies and decompressions either by same day surgery or overnight stay at a single institution beginning in October 2021 were prospectively enrolled. This study was non-randomized, non-blinded with the first cohort of consecutive patients receiving 1 g of intravenous TXA intra-operatively before closure and the second cohort of consecutive patients receiving no TXA. Exclusion criteria included any revision surgery, any surgery for the diagnosis of spinal instability, infection, tumor, or trauma, any contraindication for TXA. Results: Eighty-four patients were included in the study, with 45 (54%) receiving TXA and 39 (46%) not receiving TXA. Median follow-up was 168 days [interquartile range (IQR), 85-368 days]. There were no differences in patient or surgical characteristics between cohorts. Estimated blood loss (EBL) was similar (P=0.20), while post-operative drain output was significantly lower in the TXA cohort (P=0.0028). Single level discectomies had significantly less drain output as compared to 2 level unilateral laminotomy, bilateral decompression (ULBD) cases (P<0.005). Post-operative complications were similar, with low rates of wound complication (1.2%) and transient postoperative weakness (2.4%, P>0.99 for both). Oswestry disability index (ODI), visual analog scale (VAS) back and VAS leg scores decreased significantly; the absolute decrease in scores did not differ between groups (P=0.71, 0.22, 0.86, respectively). Conclusions: Systemic intraoperative TXA administration is associated with a significant decrease in post-operative blood loss in biportal spinal endoscopy, with no impact on the improvement in patient-reported outcomes (PROs) or rate of post-operative complications. Single level biportal discectomies had significantly less postoperative drainage with TXA and may not need drains postoperatively. Larger, randomized studies are necessary to evaluate the cost-effectiveness of TXA use in biportal spinal endoscopy.

Biportal endoscopic transforaminal lumbar interbody fusion using a large cage for degenerative spondylolisthesis with stenosis.

Recently, biportal endoscopic transforaminal lumbar interbody fusion (TLIF) has been used to treat lumbar degenerative diseases, such as lumbar instability and spondylolisthesis. Biportal endoscopic TLIF may have the advantages of endoscopic spine approaches and minimally invasive lumbar fusion surgeries. In this biportal endoscopic TLIF, large cages similar to oblique lumbar interbody fusion (OLIF) cages have been used. Biportal endoscopic TLIF using a large cage can be successfully performed in the lower lumbar area. The author presents the surgical technique of biportal endoscopic TLIF using a large cage. The video can be found here: https://stream.cadmore.media/r10.3171/2024.1.FOCVID23231.

Biportal endoscopic posterior cervical foraminotomy with discectomy for unilateral radicular arm pain due to cervical herniated disc.

Recently, biportal endoscopic cervical approaches have been used to treat cervical degenerative disease. Biportal endoscopic posterior cervical foraminotomy with or without discectomy has the advantage of reducing damage to the normal tissues during surgery and enhancing fast recovery after surgery. The biportal endoscopic cervical approach was performed using two portals. The first portal was an endoscopic viewing portal for the spinal endoscope, and the other portal was a working portal for using surgical instruments. The author illustrates the surgical technique of biportal endoscopic posterior cervical foraminotomy with discectomy. The video can be found here: https://stream.cadmore.media/r10.3171/2024.1.FOCVID23225.

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 Approach for Lumbar Degenerative Disease in the Ambulatory Outpatient vs Inpatient Setting: A Comparative Study.

BACKGROUND: Biportal spinal endoscopy is increasingly utilized for lumbar disc herniations and lumbar stenosis. The objective was to investigate the safety and effectiveness of the technique in the outpatient vs inpatient setting. METHODS: This is a comparative study of consecutive patients who underwent biportal spinal endoscopy by a single surgeon at a single institution. Demographics, surgical complications, and patient-reported outcomes were prospectively collected and retrospectively analyzed. Statistics were calculated among treatment groups using unpaired t test and χ 2 analysis where appropriate. Statistical significance was determined as P < 0.05. RESULTS: Eighty-four patients were included, 58 (69.0%) as outpatient, 26 (31.0%) as inpatient. Mean follow-up was 7.5 months. Statistically significant differences in age, American Society of Anesthesiologists classification, and Charleston Comorbidity Index scores were reported between cohorts, with younger and healthier patients undergoing outpatient surgery (P < 0.0001). Outpatients were more likely to have discectomies while inpatients were more likely to have decompressions for stenosis. No significant differences in postoperative complications were found between groups.Both cohorts demonstrated significant improvement in visual analog scale (VAS) back and leg pain scores and Oswestry Disability Index scores (P < 0.001). Outpatients had significantly lower postoperative VAS back pain (P = 0.001) and Oswestry Disability Index scores (P = 0.004) at 5-8 weeks compared with inpatients, but there was no significant difference for VAS leg pain scores at all time points between the cohorts. CONCLUSIONS: Early results demonstrate that biportal spinal endoscopy can safely and effectively be performed in both inpatient and outpatient settings. CLINICAL RELEVANCE: Outpatient biportal spinal endoscopy can be performed successfully in well selected patients, which may reduce the financial burden of spine surgery to the U.S. healthcare system.

Enhanced recovery after surgery pathway with modified biportal endoscopic transforaminal lumbar interbody fusion using a large cage. Comparative study with minimally invasive microscopic transforaminal lumbar interbody fusion.

PURPOSE: Studies about the clinical efficacy of endoscopic lumbar interbody fusion using an enhanced recovery after surgery (ERAS) pathway are insufficient. Thus, the purpose of this study was to investigate clinical usefulness of biportal endoscopic transforaminal lumbar interbody fusion (TLIF) using an ERAS compared with microscopic TLIF. METHODS: Prospectively collected data were retrospectively analyzed. Patients who received modified biportal endoscopic TLIF with ERAS were grouped into an endoscopic TLIF group. Those who received microscopic TLIF without ERAS were grouped into a microscopic TLIF group. Clinical and radiologic parameters were compared between two groups. Fusion rate was evaluated using sagittal reconstruction images of postoperative computed tomographic (CT) scan. RESULTS: There were 32 patients in the endoscopic TLIF group with ERAS and 41 patients in the microscopic TLIF group without ERAS. Visual analog scale (VAS) scores for back pain preoperatively at day one and day two were significantly (p < 0.05) higher in the non-ERAS microscopic TLIF group than in the ERAS endoscopic TLIF group. Preoperative Oswestry Disability Index were significantly improved at the last follow-up in both groups. The fusion rate at postoperative one year was 87.5% in the endoscopic TLIF group and 85.4% in the microscopic TLIF group. CONCLUSION: Biportal endoscopic TLIF with ERAS pathway may have good aspect to accelerate recovery after surgery. There was no inferiority of fusion rate of endoscopic TLIF comparing to microscopic TLIF. Biportal endoscopic TLIF using a large cage with ERAS pathway may be a good alternative treatment for lumbar degenerative disease.

Biportal Endoscopic Posterior Cervical Foraminotomy for Adjacent 2-Level Foraminal Lesions Using a Single Approach (Sliding Technique).

OBJECTIVE: Endoscopic posterior cervical foraminotomy (PCF) using uniportal or biportal endoscopic approach has been performed for cervical foraminal stenosis or foraminal disc herniation. Two-level PCF is possible using a single biportal endoscopic approach. The purpose of this study was to present a technique of biportal endoscopic PCF for contiguous 2-level foraminal lesions using a single approach and its clinical results. METHODS: Patients who received 2-level PCF using a single biportal endoscopic approach were enrolled in this study. We analyzed their clinical data including age, sex, complications, and Neck Disability Index (NDI), and visual analogue scale (VAS) of neck and arm. Postoperative magnetic resonance image was taken on the first postoperative day to determine whether there was sufficient decompression. RESULTS: We successfully performed biportal endoscopic PCF for adjacent 2-level foraminal lesions using a single approach (sliding technique) in all 12 patients. There were cervical foraminal disc herniation with foraminal stenosis (5 cases) and 2-level foraminal stenosis (7 cases). Preoperative mean NDI and VAS of arm and neck significantly decreased at 12 months after surgery. Postoperative clinical outcomes were excellent in 5 patients, good in 6 patients, and fair in 1 patient. There was no major complication. CONCLUSION: Two-level PCF could be performed using a single approach biportal endoscopic surgery with only 2 skin incisions. Clinical outcomes are favorable. This sliding PCF technique using biportal endoscopic approach might be an alternative surgical treatment for contiguous 2-level cervical foraminal pathologic lesions.

The Use of Dual Direction Expandable Titanium Cage With Biportal Endoscopic Transforaminal Lumbar Interbody Fusion: A Technical Consideration With Preliminary Results.

OBJECTIVE: Expandable cage technology has emerged for lumbar interbody fusion to restore intervertebral disc space height and alignment through a narrow surgical corridor. The purpose of this study is to present the technique of biportal endoscopic transforaminal lumbar interbody fusion (TLIF) using dual direction expandable cage and provide early clinical results. METHODS: We performed the biportal endoscopic TLIF using a dual direction expandable titanium cage for height restoration and a larger footprint in 10 patients. Clinical parameters including Oswestry Disability Index (ODI), visual analogue scale (VAS), and complications were retrospectively analyzed. Also, we investigated radiologic parameters using preoperative and postoperative x-ray images. RESULTS: We successfully inserted dual direction expandable cages during biportal endoscopic TLIF. There was no significant subsidence or collapse of the expandable cages during the 6-month follow-up period. Lumbar lordosis and disc height were significantly increased after surgery. ODI and VAS scores were significantly improved at 6 months after surgery. CONCLUSION: In this report, we describe the first use of a dual direction expandable interbody TLIF cage that expands in both width and height in biportal endoscopic TLIF surgery. Early clinical and radiographic outcomes of this TLIF technique may be favorable in early 6-month follow-up.

Clinical outcomes and complications after biportal endoscopic spine surgery: a comprehensive systematic review and meta-analysis of 3673 cases.

PURPOSE: Current literature suggests that biportal spinal endoscopy is safe and effective in treating lumbar spine pathology such as lumbar disc herniation, lumbar stenosis, and degenerative spondylolisthesis. No prior study has investigated the postoperative outcomes or complication profile of the technique as a whole. This study serves as the first comprehensive systematic review and meta-analysis of biportal spinal endoscopy in the lumbar spine. METHODS: A PubMed literature search provided over 100 studies. 42 papers were reviewed and 3673 cases were identified with average follow-up time of 12.5 months. Preoperative diagnoses consisted of acute disc herniation (1098), lumbar stenosis (2432), and degenerative spondylolisthesis (229). Demographics, operative details, complications, and perioperative outcome and satisfaction scores were analyzed. RESULTS: Average age was 61.32 years, 48% male. 2402 decompressions, 1056 discectomies, and 261 transforaminal lumbar Interbody fusions (TLIFs) were performed. Surgery was performed on 4376 lumbar levels, with L4-5 being most common(61.3%). 290 total complications occurred, 2.23% durotomies, 1.29% inadequate decompressions, 3.79% epidural hematomas, and < 1% transient nerve root injuries, infections, and iatrogenic instability. Significant improvement in VAS-Back, VAS-Leg, ODI, and Macnab Scores were seen across the cohort. CONCLUSION: Biportal spinal endoscopy is a novel method to address pathology in the lumbar spine with direct visualization through an endoscopic approach. Complications are comparable to previously published rates. Clinical outcomes demonstrate effectiveness. Prospective studies are required to assess the efficacy of the technique as compared to traditional techniques. This study demonstrates that the technique can be successful in the lumbar spine.

Temperature change of epidural space by radiofrequency use in biportal endoscopic lumbar surgery: safety evaluation of radiofrequency.

PURPOSE: Articles evaluating radiofrequency (RF) safety are insufficient. Thus, the purpose of this study was to investigate RF safety during biportal endoscopic lumbar decompressive laminotomy by measuring epidural temperature after RF use. METHODS: Both in vitro cadaveric study and in vivo study were performed. The epidural temperature was measured at epidural space after RF use in three cadavers. The epidural temperature was measured and analysed according to RF mode, RF power, RF usage time, and saline irrigation patency. In the in vivo study, the epidural temperature was measured after biportal endoscopic surgery. Epidural temperatures were measured around ipsilateral and contralateral traversing nerve roots after 1-s use of RF. RESULTS: In the in vivo study, epidural space temperature was increased by 0.31 ± 0.16 °C ipsilaterally and 0.29 ± 0.09° contralaterally after RF use in coagulation mode 1. The epidural temperature of epidural space was increased by 0.21 ± 0.13 °C ipsilaterally and 0.15 ± 0.21 °C contralaterally after RF use in high mode 2. In the in vitro study, epidural temperature was significantly increased with a long duration of RF use and a poor patency of irrigation fluid. CONCLUSION: The use of RF in biportal endoscopic spine surgery might be safe. In order to reduce indirect thermal injuries caused by RF use, it might be necessary to reduce RF use time and maintain continuous saline irrigation patency well.

Minimally invasive endoscopy in spine surgery: where are we now?

INTRODUCTION: Endoscopic spine surgery (ESS) is a minimally invasive surgical technique that offers comparable efficacy and safety with less collateral damage compared to conventional surgery. To achieve clinical success, it is imperative to stay abreast of technological advancements, modern surgical instruments and technique, and updated evidence. PURPOSES: To provide a comprehensive review and updates of ESS including the nomenclature, technical evolution, bibliometric analysis of evidence, recent changes in the spine communities, the prevailing of biportal endoscopy, and the future of endoscopic spine surgery. METHODS: We conducted a comprehensive review of the literature on ESS for the mentioned topics from January 1989 to November 2022. Three major electronic databases were searched, including MEDLINE, Scopus, and Embase. Covidence Systematic Review was used to organize the eligible records. Two independent reviewers screened the articles for relevance. RESULTS: In total, 312 articles were finally included for review. We found various use of nomenclatures in the field of ESS publication. To address this issue, we proposed the use of distinct terms to describe the biportal and uniportal techniques, as well as their specific approaches. In the realm of technical advancement, ESS has rapidly evolved from addressing disc herniation and spinal stenosis to encompassing endoscopic fusion, along with technological innovations such as navigation, robotics, and augmented reality. According to bibliometric analysis, China, South Korea, and the USA have accounted for almost three-quarters of total publications. The studies of the biportal endoscopy are becoming increasingly popular in South Korea where the top ten most-cited articles have been published. The biportal endoscopy technique is relatively simple to adopt, as it relies on a more familiar approach, requires less expensive instruments, has a shorter learning curve, and is also well-suited for interbody fusion. The uniportal approach provided the smallest area of soft tissue dissection. While robotics and augmented reality in ESS are not widely embraced, the use of navigation in ESS is expected to become more streamlined, particularly with the emergence of recent electromagnetic-based navigation technologies. CONCLUSIONS: In this paper, we provide a comprehensive overview of the evolution of ESS, as well as an updated summary of current trends in the field, including the biportal and uniportal approaches. Additionally, we summarize the nomenclature used in ESS, present a bibliometric analysis of the field, and discuss future directions for the advancement of the field.

Indications, Contraindications, and Complications of Biportal Endoscopic Decompressive Surgery for the Treatment of Lumbar Stenosis: A Systematic Review.

BACKGROUND: Biportal endoscopic spine surgery is gaining popularity in managing degenerative lumbar diseases and has optimal indications and contraindications. The perioperative complications related to the biportal endoscopic approach affect the postoperative outcomes. Therefore, this study aimed to review the indications, contraindications, and complications of biportal endoscopic decompression for lumbar stenosis. METHODS: For this systematic review, articles on biportal endoscopic decompressive surgery for lumbar stenosis, including central, lateral recess and foraminal stenoses, were searched for and reviewed. Additionally, the complications, indications, and contraindications of biportal endoscopic surgery for lumbar stenosis were reviewed. RESULTS: Forty-one articles were included in this study. The indications for biportal endoscopic decompression are central lumbar stenosis, central stenosis with lipomatosis, lateral recess stenosis, foraminal stenosis, and the far-out syndrome. The contraindications include trauma, infection, tumor, instability, high-grade spondylolisthesis, isthmic spondylolisthesis, and severe scoliosis. Perioperative complications are typically minor; major complications include durotomy, epidural hematoma, incomplete decompression, infection, facet joint injury, neural injury, increased epidural pressure, and postoperative instability. CONCLUSIONS: Favorable indications for a biportal endoscopic approach are central lumbar, lateral recess, foraminal, extraforaminal stenoses, and the Bertolotti syndrome. Incidental durotomy and postoperative epidural hematomas are common complications of biportal endoscopic decompression.

The Future of Minimally Invasive Spine Surgery.

Minimally invasive spine surgery (MISS) is an important option for spinal operations, with advantages including rapid recovery and preservation of normal structures. As the number of geriatric patients is increasing, the role of MISS might expand in the future. MISS techniques and approaches continue to be developed, and recent trends in MISS development include the refinement of surgical approaches and techniques, as well as systems related to newly developed techniques, rather than spinal implants. Among the various techniques for MISS, endoscopic spine surgery, including uniportal and biportal endoscopic approaches, is the focus of vigorous research efforts that may lead to further expansion of the indications of endoscopic spine surgery. Endoscopic spine surgery will be an important part of spine surgery. Lateral lumbar interbody fusion and endoscopic lumbar interbody fusion may play meaningful roles in the MISS fusion area. Robotics and augmented reality are also likely to be important technological modalities in spine surgery in the future.

Comparative Analysis With Modified Inclined Technique for Posterior Endoscopic Cervical Foraminotomy in Treating Cervical Osseous Foraminal Stenosis: Radiological and Midterm Clinical Outcomes.

OBJECTIVE: We compared the midterm clinical and radiological outcomes between 2 types of full endoscopic posterior cervical foraminotomy, including conventional posterior endoscopic cervical foraminotomy (PECF) and modified inclined technique for PECF. METHODS: One of the 2 types of PECF surgery was performed for defined cervical foraminal stenosis. The foraminal expansion ratio and facet resection rate and foraminal stenosis grade were measured using magnetic resonance imaging. Visual analogue scale (VAS) scores for neck and arm pain, neck disability index, MacNab criteria, operation time, hospital stay, and complications, including postoperative dysesthesia, were assessed. Clinical and radiological parameters were compared between the 2 surgical groups. RESULTS: There were 49 and 46 patients in the PECF and modified-PECF groups, respectively. The modified-PECF group showed significantly higher expansion of distal foraminal diameter and foraminal height, and a lower facet resection rate compared to PECF group (in all, p < 0.001). The modified-PECF group displayed significantly lower VAS score for neck pain at 1 day and 1 week after surgery and lower arm pain VAS score after 6-month follow-up (p = 0.002, p = 0.001, p = 0.002, respectively). CONCLUSION: Compared with the PECF, the modified inclined technique has radiologic benefits, including enhanced facet joint preservation, restoration of the natural course of nerve roots, and prevention of restenosis by expanding the superior articular process base, especially in grade 2 foraminal stenosis. Furthermore, the modified inclined technique significantly improved the postoperative VAS score for neck pain within the 1-week follow-up and that of arm pain after 6-month follow-up.

Surgical Removal of Cervical Extradural Cysts Using the Biportal Endoscopic Approach.

BACKGROUND: Symptomatic intraspinal extradural cysts of the cervical spine are uncommon; however, they are usually treated using conventional posterior decompression. Biportal endoscopic surgery is widely used to treat degenerative cervical pathological conditions. This study presented an optimized surgical technique for a biportal endoscopic posterior approach for removal of cervical intraspinal extradural cysts that caused cervical radiculomyelopathy. METHODS: A broad laminotomy was performed, which was wider than the outer contour of the cysts. The ligamentum flavum was detached from the bony margin and removed after an epidural dissection, and a dense adhesive tissue entrapped the extradural cysts. A spinal endoscope was placed close to the dissection plane and offered a high-resolution magnified view. The cyst capsule was safely dissected from the dura and removed en bloc without dural injury. RESULTS: Postoperatively, neurological deficits, including cervical myelopathy, radiating arm pain, and upper back pain improved in both patients. CONCLUSIONS: We successfully removed an extradural cervical cystic mass lesion by using a biportal endoscopic posterior cervical approach without complications. The biportal endoscopic approach may have advantages, such as minimizing trauma to the normal structures of the posterior cervical region, magnified endoscopic view, and early recovery after the surgery. Biportal endoscopy may be used as an alternative surgical treatment for symptomatic cervical intraspinal extradural cystic lesions.

Clinical Experiences of 3-Dimensional Biportal Endoscopic Spine Surgery for Lumbar Degenerative Disease.

BACKGROUND: The lack of stereoscopic vision in endoscopic spine surgery may lead to a risk of neural or vascular injury during endoscopic surgery. Three-dimensional (3D) endoscopy has not yet been attempted in the field of spinal endoscopic surgery. OBJECTIVE: To present the technique, clinical efficacy, and safety of the 3D biportal endoscopic approach for the treatment of lumbar degenerative disease. METHODS: We attempted 3D biportal endoscopic surgery for lumbar degenerative disease in a series of patients. Clinical outcomes and complications were evaluated postoperatively using a short questionnaire about 3D biportal endoscopic spine surgery that solicited respondents' opinions on the advantages and disadvantages of 3D biportal endoscopic surgery compared to the conventional 2D biportal endoscopic approach. RESULTS: We performed 3D biportal endoscopic spine surgery in 38 patients with lumbar degenerative disease. Optimal neural decompression was revealed by postoperative magnetic resonance imaging in all enrolled patients. The 3D endoscopic vision clearly demonstrated the surgical anatomy starting with the exposure of ligamentum flavum, dura, and nerve root, and 3D endoscopy precisely depicted pathologic lesions such as bony osteophytes and ruptured disc herniation. There were no major complications including neural injury or durotomy. CONCLUSION: The 3D endoscope may be able to distinguish between normal structures and lesions. The stereognosis and depth sensation of 3D biportal endoscopic spinal surgery might have a favorable impact on the safety of patients during endoscopic spine surgery.

Comparing the efficacy and safety of minimally invasive biportal endoscopic spine surgery versus conventional microscopic discectomy in single-level lumbar herniated intervertebral disc (ENDO-BH Trial): a multicenter, prospective, randomized controlled equivalence trial study protocol.

BACKGROUND: Biportal endoscopic surgery has recently been performed in lumbar discectomy, with advantages over conventional surgery, such as less skin scarring and muscle damage. However, the clinical results have not been established. Although previous studies reported no difference between the biportal endoscopic and microscopic discectomy clinical results, the evidence was weak. Therefore, this study aims to evaluate the efficacy and safety of the biportal endoscopic discectomy versus the microscopic discectomy. METHODS: This prospective multicenter randomized controlled equivalence trial is designed to compare the efficacy and safety outcomes of patients who underwent lumbar discectomy using biportal endoscopy or microscopy. We will include 100 participants (50 per group) with a lumbar herniated disc. The primary outcome will be the Oswestry Disability Index (ODI) score 12 months after surgery based on a modified intention-to-treat strategy. The secondary outcomes will include the visual analog scale score for low back and lower extremity radiating pain, the ODI score, the Euro-Qol-5-Dimensions score, surgery satisfaction, walking time, postoperative return to daily life period, postoperative surgical scar, and surgery-related variables, such as postoperative drainage, operation time, admission duration, postoperative creatine kinase, and implementation status of conversion to open surgery. Radiographic outcomes will also be analyzed using magnetic resonance imaging (MRI) or computed tomography (CT) and simple radiographs. Safety will be assessed by evaluating all adverse and severe adverse events and surgery-related effects. The participants will be assessed by a blinded assessor before surgery (baseline) and 2 weeks and 3, 6, and 12 months after surgery. DISCUSSION: This trial will be the first prospective, multicenter, randomized controlled trial to analyze the efficacy and safety of biportal endoscopic discectomy in lumbar herniated disc. This trial is designed for evaluating the equivalence of the results between biportal endoscopic and microscopic discectomy including adequate sample size, blinded analyses, and prospective registration to reduce bias. This trial will provide enough data on the effectiveness and safety of biportal endoscopic surgery and will be an important study that allows clear conclusions. TRIAL REGISTRATION: Clinical Research Information Service (cris.nih.go.kr.) ( KCT0006191 ). Registered on 27 March 2021.

Thermal Dynamics of a Novel Radio-Frequency Device for Endoscopic Spine Surgery: An Experimental Model.

STUDY DESIGN: Experimental study. OBJECTIVE: In this study, the ambient temperature of a radiofrequency (RF) electrode tip was compared and analyzed in terms of products, mode, flow quantity, and flow rate. SUMMARY OF BACKGROUND DATA: Endoscopic spine surgery is a widely used operation for degenerative lumbar stenosis and herniated lumbar disc. To perform endoscopic spine surgery, dedicated instruments like a RF generator and electrode are essential. METHODS: An evaluation system capable of measuring temperature under equal conditions at a certain distance from the electrode tip was manufactured. The distance between the electrode tip and the temperature sensor was set to 1, 5, and 10 mm. The flow quantities of 0, 50, 100, and 150 mL/min and the flow rates of 0, 0.20, 0.53, and 0.80 m/s were compared and statistically analyzed. RESULTS: The temperatures measured in the experiments conducted on the four combinations of RF device showed similar values, and showed differences according to the characteristics of each mode of the RF. As the distance between the electrode tip and the temperature sensor increased, the temperature decreased, and as flow quantity or flow rate increased, the temperature decreased. The maximum temperatures differed significantly according to flow quantity, between flow quantities of 0 and 100 mL/min (P  = 0.03) and between 0 and 150 mL/min (P ≤ 0.01). The maximum temperatures also differed significantly between the flow rate of 0 m/s, and the flow rates of 0.20, 0.53, and 0.80 m/s, with P ≤ 0.01 in all three comparisons. CONCLUSION: This is the first study in which we made a customized RF temperature evaluation system and verified the temperature changes in various environments. When irrigation was performed, we could confirm that the maximum temperature was less than 60°C. Irrigation is considered essential in endoscopic spine surgery. LEVEL OF EVIDENCE: 3.

Repair of Incidental Durotomy Using Sutureless Nonpenetrating Clips via Biportal Endoscopic Surgery.

STUDY DESIGN: Technical report. OBJECTIVES: Dural tear is one of the most common complications of endoscopic spine surgery. Although endoscopic dural repair of the durotomy area may be difficult, we successfully repaired the dural tear area using nonpenetrating clips during biportal endoscopic surgery. We introduce the surgical technique of dural repair using nonpenetrating titanium clips in biportal endoscopic spine surgery and report its clinical outcome. METHODS: We retrospectively reviewed and analyzed 5 patients who were treated via primary dural repair using nonpenetrating titanium clips during biportal endoscopic lumbar surgery. The 2 methods of dural clipping and repair include 2 or 3 portals. We analyzed radiological parameters such as cerebrospinal fluid collection as well as clinical parameters, including postoperative clinical outcomes. RESULTS: Five patients underwent biportal endoscopic dural repair using nonpenetrating clips. Incidental durotomy was successfully repaired using nonpenetrating titanium clips in all 5 patients. No cerebrospinal fluid collection was detected in the postoperative magnetic resonance images. Clinically, preoperative symptoms improved significantly after surgery (P < .05). CONCLUSIONS: We repaired the dural tear area completely using nonpenetrating titanium vascular anastomosis clips in biportal endoscopic lumbar surgery. Dural repair via clipping method may be an effective alternative for incidental durotomy.