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 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 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.

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.

Digital coincidence counting with 4πβ(PPC)-γ for the standardization of 60Co

A 4πβ(PPC)-γ coincidence system has been made at KRISS based on a digital DAQ. 60Co sources were measured to verify the system. The maximum detection efficiency for beta particles was estimated to be 96.7 %. Massic activities for sample sources had 0.005 % of the sample variability error, which was well within the expanded standard uncertainty of 0.54 % (k = 2).

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.

LEVEL OF EVIDENCE: 3

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.

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.

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.

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.

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.

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.

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.

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

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.

Biportal Endoscopic Technique for Transforaminal Lumbar Interbody Fusion: Review of Current Research

BACKGROUND

There are many types of minimally invasive lumbar interbody fusion procedures. Among them is the recently introduced biportal endoscopic lumbar interbody fusion surgery. Biportal endoscopic transforaminal lumbar interbody fusion (TLIF) might combine the advantages of minimally invasive TLIF and endoscopic spine approaches. However, clinical evidence in support of biportal endoscopic TLIF remains insufficient.

METHODS

A comprehensive review of English-language literature on biportal endoscopic lumbar interbody fusion was performed. Articles on biportal endoscopic TLIF in PubMed, the Cochrane Library, and Web of Science were searched using the terms "unilateral biportal endoscopy," "biportal endoscopic spine surgery," "transforaminal," and "lumbar interbody fusion" as well as their combinations. The clinical and radiological outcomes of biportal endoscopic TLIF were analyzed and are summarized here. The biportal endoscopic lumbar interbody fusion surgical techniques are then described.

RESULTS

There are 3 biportal endoscopic TLIF techniques. In the available literature, the postoperative 1-year outcomes of biportal endoscopic TLIF were comparable to those of posterior lumbar interbody fusion (PLIF) and minimally invasive (MIS)-TLIF. Clinical parameters were significantly improved after biportal endoscopic TLIF. Compared to PLIF or MIS-TLIF, biportal endoscopic-TLIF may have the advantage of a faster recovery. Biportal endoscopic TLIF showed no inferiority in fusion rates compared to PLIF or MIS-TLIF. The postoperative complications were usually minor.

CONCLUSIONS

The postoperative 1-year clinical and radiological outcomes of biportal endoscopic TLIF were favorable compared to those of PLIF and MIS-TLIF. However, long-term outcomes should be investigated through prospective, randomized controlled trials in the future.

CLINICAL RELEVANCE

This review article outlines the most current evidence-based medicine with regard to spinal surgery with an aim to introduce a new technique.

Contralateral sublaminar approach for decompression of the combined lateral recess, foraminal, and extraforaminal lesions using biportal endoscopy: a technical report

BACKGROUND

The development of specialized instruments and surgical techniques has enabled the biportal endoscopic system to access the foraminal and extraforaminal area using the contralateral sublaminar approach at the lumbar level.

METHODS

Biportal endoscopic contralateral sublaminar approach was used to resolve the contralateral foraminal, and extraforaminal stenosis at the lumbar level. Prominent syndesmophytes and herniated disc compression of the exiting nerve root were successfully removed, and the distorted nerve root was restored to a smooth downward angulation in the far-out area.

CONCLUSION

We successfully utilized biportal endoscopy to decompress the combined lumbar lateral recess, foraminal, and extraforaminal lesions using a contralateral sublaminar approach.

Biportal endoscopic unilateral laminotomy with bilateral decompression for the treatment of cervical spondylotic myelopathy

BACKGROUND

The advantages of biportal endoscopic approaches over conventional open surgery include the preservation of the normal structures, less intraoperative bleeding, fast postoperative recovery, and preservation of the motion segments.

METHOD

We attempted the posterior biportal endoscopic approach for cervical stenosis at the C5-C6-C7 levels. Biportal endoscopic right ipsilateral hemilaminectomy with bilateral decompression at the C5-C6-C7 levels and right foraminotomy at the C6-C7 level were performed under general anesthesia.

CONCLUSIONS

We successfully performed neural decompression at the C5-C6-C7 levels using biportal endoscopic surgery. The biportal endoscopic posterior cervical approach may be an alternative surgical method for treating cervical myelopathy.

Modified far lateral endoscopic transforaminal lumbar interbody fusion using a biportal endoscopic approach: technical report and preliminary results

BACKGROUND

Endoscopic transforaminal lumbar interbody fusion (TLIF) has the disadvantage of the small cage size and by consequence risk for cage subsidence. We succeeded to insert a large oblique lumbar interbody fusion (OLIF) cage during biportal endoscopic TLIF.

METHODS

Unilateral total facetectomy was performed to expose the exiting and traversing nerve roots. The distance between the exiting and traversing nerve roots was measured before OLIF cage insertion. We inserted an OLIF cage instead of a TLIF cage.

CONCLUSION

We successfully performed modified far lateral biportal endoscopic TLIF using large OLIF cages. Modified far lateral biportal endoscopic TLIF is usually suitable for the L4-5 and L5-S1 levels.

Clinical Results and Complications of Endoscopic Lumbar Interbody Fusion for Lumbar Degenerative Disease: A Meta-Analysis

BACKGROUND

Although endoscopic transforaminal lumbar interbody fusion (TLIF) may combine the advantages of minimally invasive fusion and endoscopic spine surgery, little evidence exists on endoscopic TLIF. This meta-analysis investigated the clinical results of endoscopic TLIF.

METHODS

We performed a systematic search of Web-based electronic databases to identify articles on endoscopic lumbar interbody fusion. Only studies of water-based endoscopic TLIF with pedicle screw fixation were included. We analyzed preoperative and postoperative scores for the Oswestry Disability Index (ODI) and visual analog scales (VASs) for back and leg pain to evaluate clinical efficacy. The minimal clinically important difference (MCID) of VAS and ODI was analyzed. We calculated differences in means and 95% confidence intervals and investigated indications for endoscopic TLIF, surgical approaches for endoscopic TLIF, the endoscopic systems that were used, and procedure-related complications.

RESULTS

Thirteen articles were included in this meta-analysis. Uniportal and biportal endoscopic systems were used. Six articles used the posterolateral approach and 7 used the trans-Kambin approach. Preoperative ODI and VAS scores for leg and back pain significantly improved after endoscopic TLIF with percutaneous pedicle screw fixation (P = 0.00). The ODI significantly improved by twice as much as the MCID. The mean change in the VAS for back and leg pain showed significant improvements over the MCID. The perioperative complications were usually minor.

CONCLUSIONS

The early clinical results of endoscopic TLIF with percutaneous pedicle screw fixation are favorable. However, long-term outcomes should be investigated and randomized controlled trials should be conducted.

Is it sufficient to treat adult lumbar spinal deformity using anterior lumbar interbody fusion with percutaneous pedicle screw fixation?

Anterior lumbar interbody fusion (ALIF) has been performed for lumbar spinal restoration and stabilization without extensive paraspinal muscle damage or massive bleeding. The authors retrospectively investigated surgical results of multilevel ALIF followed by percutaneous pedicle screw fixation (PPSF) in adult lumbar spinal deformity (ALSD). This study included 28 patients with degenerative lumbar spinal deformity, who underwent selective multilevel ALIF and PPSF between January 2013 and August 2016 at our hospital. Standing X-rays were performed and coronal Cobb angle (CCA) of scoliosis, sagittal vertical axis (SVA), lumbar lordosis (LL), thoracic kyphosis (TK), pelvic tilt (PT), and sacral slope (SS) were measured. Pain and functional assessment were performed using visual analogue scale (VAS) scores for low back pain and leg pain, and Oswestry Disability Index (ODI) scores. CCA, SVA and LL were significantly improved immediately after surgery and relatively well maintained until the last follow-up. After surgery, PT was significantly decreased and SS was increased, respectively. However, cases with SVA > 95 mm or PT > 30° showed a loss of correction in sagittal balance parameters to a greater extent at the last follow-up compared to the group of patients with minor sagittal imbalance. VAS scores for back and radicular pain, and ODI score were significantly decreased at the final follow-up (p < 0.05). Multilevel ALIF with PPSF yielded favorable clinical and radiological outcomes in coronal and sagittal balance without severe surgical mortality or morbidity in patients with ALSD. However, correction loss in sagittal balance was observed in cases with SVA > 95 mm or PT > 30˚.

Technique of Biportal Endoscopic Transforaminal Lumbar Interbody Fusion

Biportal endoscopic transforaminal lumbar interbody fusion (TLIF) may have advantages of minimally invasive fusion surgery as well as those of endoscopic surgery. The purpose of this study was to present the biportal endoscopic TLIF technique along with video presentations and a review of the literature on this technique. Basically, the biportal endoscopic TLIF technique is similar to minimally invasive TLIF with a tubular retractor. There were 2 options in the biportal endoscopic TLIF procedures. The first was the insertion of one long TLIF cage and the other was the insertion of 2 short posterior lumbar interbody fusion (PLIF) cages. After the interbody fusion procedures, percutaneous pedicles screw fixation was performed. Biportal endoscopic TLIF achieved complete neural decompression through laminectomy and facetectomy like conventional TLIF. Endplate preparation was performed completely under a clear and magnified endoscopic view. It was also feasible to insert a large TLIF cage or 2 cages for PLIF without exiting nerve root injury. Biportal endoscopic TLIF might have the advantages of endoscopic surgery as well as minimally invasive fusion surgery. Direct neural decompression, endplate preparation under endoscopic guidance, and the insertion of a large TLIF cage or 2 PLIF cages may be the merits of biportal endoscopic lumbar fusion procedures.

The primary system for measurement of beta emitting radioactive gases at KRISS

Korea Research Institute of Standards and Science (KRISS) is developing a length-compensated proportional counting (LCPC) system as a primary system for standardization of beta emitting radioactive gases. The pilot experiment was performed with ⁸⁵Kr and the optimized high voltage and pressure were found to be 1700 V and 0.203 MPa, respectively. The total activity of ⁸⁵Kr was deduced by the length compensation of each count. The expanded uncertainty was estimated to be around 0.8% (k = 2) for the ⁸⁵Kr measurement.

Fully Endoscopic Transforaminal Lumbar Discectomy for Upward Migration of Upper Lumbar Disc Herniation: Clinical and Radiological Outcomes and Technical Considerations

Microdiscectomy for the upward migration of upper lumbar herniated discs has a high risk of isthmus and facet injury. Fully endoscopic transforaminal discectomy can preserve normal bony structures during discectomy. The purpose of this study was to assess the clinical and radiological outcomes of fully endoscopic transforaminal discectomy for upward migrated upper lumbar herniated discs. All patients had upward migrated disc herniation from L1–L2 to L3–L4 levels and were treated using fully endoscopic transforaminal discectomy under local anesthesia. All enrolled patients were monitored for more than 12 months. Clinical outcomes were assessed using the Oswestry Disability Index (ODI) and visual analog scale (VAS) of pain. Surgery-related complications were analyzed. In addition, radiological outcomes were investigated using postoperative magnetic resonance imaging (MRI) and lumbar dynamic X-ray. Twenty-eight patients were enrolled in this study. ODI and VAS significantly decreased after endoscopic transforaminal discectomy. Migrated ruptured disc particles were completely removed and confirmed on postoperative MRI in 26 of the 28 patients. Even though small remnant disc particles were detected in two patients, symptoms improved after endoscopic transforaminal discectomy. Early recurrence of herniated disc occurred at the operated segment in one patient. There were no significant complications associated with fully endoscopic transforaminal discectomy. Three patients experienced a postoperative transient tingling sensation and numbness of the leg. Fully endoscopic transforaminal lumbar discectomy may be an effective and alternative treatment option for upward migrated disc herniation in the upper lumbar area. In addition, fully endoscopic transforaminal lumbar discectomy may prevent complications associated with general endotracheal anesthesia and injuries of the isthmus and the facet joint.

Design of optimal digital filter and digital signal processing for a CdZnTe high resolution gamma-ray system

We have developed an online digital signal processing system based on an FPGA. The system consists of pile-up rejection, baseline restorer, peak detection and pole-zero cancellation for evaluation of deposited energy in the detector. The shaping algorithm employed is a Moving Window Deconvolution (MWD) to shape digitized data into a trapezoidal form. For the purpose of verification, the developed digital system was tested for ¹³⁷Cs gamma rays. The entire system is programmed using the LabVIEW environment.

Endoscopic transforaminal lumbar interbody fusion: a comprehensive review

INTRODUCTION

Endoscopic spine surgery has been developed as a minimally invasive technique for decompression in patients with lumbar disc herniation or lumbar stenosis. Recent reports have described the use of endoscopic technology in lumbar fusion surgeries, especially for transforaminal lumbar interbody fusion (TLIF). This review aimed to summarize the current techniques of endoscopic TLIF and to discuss the benefits, limitations, and future perspectives of endoscopic lumbar fusion surgery.

AREAS COVERED

This review covered the English-language medical literature published in Medline and focused specifically on endoscopic technologies incorporated into minimally invasive TLIF. The endoscopic TLIF techniques are categorized here according to the properties of the endoscope: percutaneous endoscopic TLIF, biportal endoscopic TLIF, and microendoscopic TLIF. Even though most authors have reported favorable clinical and radiological outcomes of endoscopic TLIF, such evidence originates mainly from case series.

EXPERT OPINION

Although the current level of evidence is low and the technical relevance of the technique is controversial, the key concept and early results of endoscopic TLIF are promising. Technical advancements to improve safety and reduce technical complexity, as well as comparative cohort studies and randomized clinical trials with long-term follow-up are required to promote the adoption of endoscopic TLIF in clinical practice.

Comparative analysis of three types of minimally invasive decompressive surgery for lumbar central stenosis: biportal endoscopy, uniportal endoscopy, and microsurgery

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.

Comparative Finite Element Analysis of Lumbar Cortical Screws and Pedicle Screws in Transforaminal and Posterior Lumbar Interbody Fusion

Objective

Lumbar cortical screw fixation (CSF), rather than pedicle screw fixation (PSF), has recently been attempted in lumbar interbody fusion. The purpose of our study was to evaluate the biomechanical stability of lumbar CSF using a finite element (FE) model.

Methods

A 3-FE model, including the L1 to S1 levels, was designed to evaluate and compare the biomechanical stability of lumbar CSF and PSF in single-level lumbar interbody fusion at L4–5. Cortical or pedicle screws were inserted bilaterally, and posterior lumbar interbody fusion (PLIF) and transforaminal lumbar interbody fusion (TLIF) were modeled at L4–5, respectively. We compared the stability of CSF to that of PSF in these 2 different anatomic variations of PLIF, as well as in TLIF.

Results

Lumbar CSF showed less stability than PSF in PLIF when the midline posterior ligaments were not preserved, but demonstrated similar stability when the ligaments were preserved. The range of motion (ROM) at the treated level in CSF was larger than that observed for PSF, in all PLIF and TLIF models. Furthermore, the ROM in the posterior ligament-sacrificing PLIF with CSF model was larger than the ROM in the posterior ligament-preserving PLIF with CSF or PSF model.

Conclusion

Based on our FE analysis, the stability of CSF is comparable to that of PSF in PLIF and TLIF when the midline posterior ligaments are preserved.

Clinical results of percutaneous biportal endoscopic lumbar interbody fusion with application of enhanced recovery after surgery

OBJECTIVE

The aims of enhanced recovery after surgery (ERAS) are to improve surgical outcomes, shorten hospital stays, and reduce complications. The objective of this study was to introduce ERAS with biportal endoscopic transforaminal lumbar interbody fusion (TLIF) and to investigate the clinical results.

METHODS

Patients were divided into two groups based on the fusion procedures. Patients who received microscopic TLIF without ERAS were classified as the non-ERAS group, whereas those who received percutaneous biportal endoscopic TLIF with ERAS were classified as the ERAS group. The mean Oswestry Disability Index (ODI) and visual analog scale (VAS) scores were compared between the two groups. In addition, demographic characteristics, diagnosis, mean operative time, estimated blood loss (EBL), fusion rate, readmissions, and complications were investigated and compared.

RESULTS

Forty-six patients were grouped into the non-ERAS group (microscopic TLIF without ERAS) and 23 patients into the ERAS group (biportal endoscopic TLIF with ERAS). The VAS score for preoperative back pain on days 1 and 2 was significantly higher in the non-ERAS group than in the ERAS group (p < 0.05). The mean operative duration was significantly higher in the ERAS group than in the non-ERAS group, while the mean EBL was significantly lower in the ERAS group than in the non-ERAS group (p < 0.05). There was no significant difference in fusion rate between the two groups (p > 0.05). Readmission was required in 2 patients who were from the non-ERAS group. Postoperative complications occurred in 6 cases in the non-ERAS group and in 2 cases in the ERAS group.

CONCLUSIONS

Percutaneous biportal endoscopic TLIF with an ERAS pathway may have good aspects in reducing bleeding and postoperative pain. Endoscopic fusion surgery along with the ERAS concept may help to accelerate recovery after surgery.

Endoscopic Treatment of Extraforaminal Entrapment of L5 Nerve Root (Far Out Syndrome) by Unilateral Biportal Endoscopic Approach: Technical Report and Preliminary Clinical Results

Objective

Far out syndrome is compression and entrapment of the L5 nerve root in the extraforaminal area between the hypertrophied L5 transverse process and the sacral ala. The purpose of this study was to describe the technique of unilateral biportal endoscopic decompression for far out syndrome and to analyze early clinical results after endoscopic decompression.

Methods

The authors consecutively performed operative treatments for 16 patients with unilateral extraforaminal entrapment of the L5 nerve root (far out syndrome) using percutaneous biportal endoscopies. We included only patients who were followed more than six months after surgery. Demographic characteristics, operative time, concomitant herniated disc, and surgical complications were investigated. Clinical outcomes were evaluated using modified MacNab criteria, the visual analogue scale (VAS) for legs, and the Oswestry Disability Index (ODI).

Results

Among 16 patients, a total of 14 cases with 4 males and 10 females were included in the study. The mean leg VAS and the ODI were significantly improved after unilateral biportal endoscopic surgery. Concomitant extraforaminal disc herniation was associated with a favorable outcome (p<0.05). Abdominal pain in the immediate postoperative period occurred in 2 patients. Abdominal pain was completely resolved with conservative management in both patients.

Conclusion

We were able to achieve successful decompression of unilateral extraforaminal entrapment of the L5 nerve root using unilateral biportal endoscopic surgery. A unilateral biportal endoscopic approach may be considered as an alternative surgical treatment for far out syndrome.

Concomitant Occlusive Vascular Lesions of Legs in Patients with Degenerative Lumbar Diseases: Do These Lesions Influence Treatment?

BACKGROUND AND STUDY AIMS

 Vascular narrowing or obstruction reduces blood flow to the lower limbs during exercise or at rest. Symptoms may range from intermittent claudication to pain at rest. Narrowing of these arteries may produce pain in the buttocks, thighs, or legs. These symptoms may resemble those of lumbar radicular pain. Spine surgeons may overlook obstructive vascular lesions of the lower limbs in patients with lumbar degenerative diseases such as spinal stenosis and spondylolisthesis. We investigated the clinical and radiologic risk factors of concomitant vascular pathologic lesions in patients with degenerative lumbar diseases.

MATERIALS AND METHODS

 If patients presented with a weak or absent dorsalis pedis artery pulse, edema of both legs, and a past history related to vascular lesions of the lower limbs, we evaluated the veins and arteries of the lower extremities using Doppler sonography. If abnormal vascular findings were detected, computed tomography angiography (CTA) of the lower extremities was performed. Radiologic and clinical risk factors of concomitant occlusive arterial lesions of the lower limb were analyzed by logistic regression analysis.

RESULTS

 In 2013, 335 patients suspected of having vascular lesions underwent Doppler sonography. Among them, CTA of the lower extremities was performed in 58 patients. The mean age was 69.4 years (35 men and 23 women). Severe narrowing or total occlusion of the leg arteries was detected in 23 patients. Partial obstructive arterial disease of the legs was detected in 14 patients. Occlusion but with good collateral circulation of the leg was found in three patients. Surgical treatment plans were cancelled or changed in 28 patients. The risk factors for occlusive arterial lesions of the legs were an abnormal ankle-brachial pressure index (ABPI), absent dorsalis pedis artery pulse, and lack of response after a pain-blocking procedure.

CONCLUSION

 If patients present with a weak or absent dorsalis pedis artery pulse, abnormal ABPI ratio, and no response after a pain-blocking procedure, the clinician should consider the possibility of severe arterial occlusion of the legs. We suggest that the differential diagnosis of obstructive arterial lesions of the legs from lumbar degenerative diseases is important to prevent unnecessary invasive surgical treatment of the lumbar spine.

Clinical and radiological outcomes of spinal endoscopic discectomy-assisted oblique lumbar interbody fusion: preliminary results

OBJECTIVE Direct neural decompression cannot be achieved by performing lateral lumbar interbody fusion (LLIF). To overcome the indirect decompressive effect of LLIF, additional endoscopic discectomy with oblique lumbar interbody fusion (OLIF) has been attempted. The purpose of this study was to assess the clinical and radiological outcomes of patients who underwent OLIF with additional endoscopic discectomy. METHODS Spinal endoscopic discectomy-assisted OLIF was attempted to remove herniated disc material. Only patients with a follow-up time that exceeded 12 months were enrolled. Clinical parameters examined were the Oswestry Disability Index and visual analog scale scores of back and leg pain. Postoperative MRI was also performed. RESULTS Fourteen patients were enrolled. Central and foraminal disc herniations were evident in 8 and 6 patients, respectively. Concomitant central or foraminal herniated discs were removed completely after additional endoscopic discectomy, and disc removal was confirmed by postoperative MRI. Mean preoperative visual analog scale scores and Oswestry Disability Index scores improved postoperatively. CONCLUSIONS OLIF with additional endoscopic discectomy results in successful direct neural decompression without posterior decompressive procedures. Endoscopic assistance might overcome the limitations of LLIF.

Fully endoscopic lumbar interbody fusion using a percutaneous unilateral biportal endoscopic technique: technical note and preliminary clinical results

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.

Bone loss of vertebral bodies at the operative segment after cervical arthroplasty: a potential complication?

OBJECTIVE Bony overgrowth and spontaneous fusion are complications of cervical arthroplasty. In contrast, bone loss or bone remodeling of vertebral bodies at the operation segment after cervical arthroplasty has also been observed. The purpose of this study is to investigate a potential complication-bone loss of the anterior portion of the vertebral bodies at the surgically treated segment after cervical total disc replacement (TDR)-and discuss the clinical significance. METHODS All enrolled patients underwent follow-up for more than 24 months after cervical arthroplasty using the Baguera C disc. Clinical evaluations included recording demographic data and measuring the visual analog scale and Neck Disability Index scores. Radiographic evaluations included measurements of the functional spinal unit's range of motion and changes such as bone loss and bone remodeling. The grading of the bone loss of the operative segment was classified as follows: Grade 1, disappearance of the anterior osteophyte or small minor bone loss; Grade 2, bone loss of the anterior portion of the vertebral bodies at the operation segment without exposure of the artificial disc; or Grade 3, significant bone loss with exposure of the anterior portion of the artificial disc. RESULTS Forty-eight patients were enrolled in this study. Among them, bone loss developed in 29 patients (Grade 1 in 15 patients, Grade 2 in 6 patients, and Grade 3 in 8 patients). Grade 3 bone loss was significantly associated with postoperative neck pain (p < 0.05). Bone loss was related to the motion preservation effect of the operative segment after cervical arthroplasty in contrast to heterotopic ossification. CONCLUSIONS Bone loss may be a potential complication of cervical TDR and affect early postoperative neck pain. However, it did not affect mid- to long-term clinical outcomes or prosthetic failure at the last follow-up. Also, this phenomenon may result in the motion preservation effect in the operative segment after cervical TDR.

Percutaneous Sacroplasty for Non-neoplastic Osteoporotic Sacral Insufficiency Fractures

Background: Osteoporosis is an important problem in those of advanced age. Osteoporosis can induce sacral insufficiency fractures (SIFs). As average life expectancy increases, the number of patients with osteoporotic SIFs also increases. Osteoporotic SIFs cause severe low back pain and immobilization. Treatment of SIFs varies from analgesia to surgery. Objectives: To describe our experience and assess the safety and effectiveness of minimally invasive percutaneous sacroplasty in patients with osteoporotic SIFs. Study Design: Retrospective evaluation. Setting: The spine and joint specialized hospital’s research center. Methods: We reviewed cases of percutaneous sacroplasty performed since 2009. We used data only from patients with osteoporotic SIFs who were followed for more than 12 months after sacroplasty. Tumor-related SIFs were excluded from our analysis. The following clinical parameters were investigated: initial diagnosis, symptoms, visual analog scale (VAS) of pain, functional mobility scale (FDC) score, past history of illness, amount of bone cement infused, and complications related to sacroplasty. Also, the following radiological parameters were analyzed: the pattern of SIFs, T-score cement leakage, and concomitant fractures in other sites. Results: Sixty-eight patients were enrolled in our study (4 men and 64 women). The mean age of the patients was 76.8 ± 6.2 years. All patients had severe osteoporosis (mean T score: -3.9 ± 0.5). Percutaneous sacroplasty was performed under fluoroscopic guidance. No major complications or procedure-related morbidity occurred. FDS and VAS scores significantly improved after sacroplasty, and the improvements lasted through the final follow-up period (P < 0.05). Limitations: This study is a retrospective analysis without a control group. Conclusion: Percutaneous sacroplasty is an effective minimally invasive treatment for osteoporotic SIFs refractory to conservative management. The study patients experienced significant relief of pain and increased mobility. Key words: Sacrum, sacroplasty, insufficiency fractures, osteoporosis, minimally invasive surgery

Percutaneous biportal endoscopic decompression for lumbar spinal stenosis: a technical note and preliminary clinical results

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.

Efficacy and Safety of Sodium Hyaluronate with 1,4-Butanediol Diglycidyl Ether Compared to Sodium Carboxymethylcellulose in Preventing Adhesion Formation after Lumbar Discectomy

OBJECTIVE

Epidural injection of hyaluronic acid may prevent adhesion formation after spine surgery, but the compounds used to stabilize hyaluronidase could interfere with its anti-adhesion effects. The present study was conducted as a clinical trial to evaluate the efficacy and safety of an experimental medical gel in preventing adhesion formation.

METHODS

This study was designed as a multicenter, randomized, double-blind, and comparative controlled clinical trial with an observation period of 6 weeks. Subjects were randomly assigned into two groups: group A with sodium hyaluronate + 1,4-butanediol diglycidyl ether (BDDE) and group B with sodium hyaluronate + sodium carboxymethylcellulose (CMC). Visual analogue scale (VAS) of back and leg pain and the Oswestry disability index (ODI) and scar score ratings were assessed after surgery.

RESULTS

Mean scar grade was 2.37±1.13 in group A and 2.75±0.97 in group B, a statistically significant difference (p=0.012). VAS of back and leg pain and ODI scores decreased significantly from baseline to 3 and 6 weeks postoperatively in both groups (p<0.001). However, VAS and ODI scores were not statistically different between groups A and B at baseline or at 3 and 6 weeks after operation (p>0.3). The number of adverse reactions related to the anti-adhesion gels was not statistically different (p=0.569), but subsequent analysis of nervous adverse reactions showed group B was superior with a statistically difference (p=0.027).

CONCLUSION

Sodium hyaluronate with BDDE demonstrated similar anti-adhesion properties to sodium hyaluronate with CMC. But, care should be used to nervous adverse reactions by using sodium hyaluronate with BDDE.

Intravenous magnesium infusion for the prevention of symptomatic cerebral vasospasm after aneurysmal subarachnoid hemorrhage

OBJECTIVE

The study examined the difference in the incidence of symptomatic cerebral vasospasm with magnesium supplementation in aneurysmal subarachnoid hemorrhage (SAH) in a Korean population.

METHODS

This retrospective analysis was performed in 157 patients diagnosed with aneurysmal SAH from January 2007 to December 2011 at a single center. Seventy patients (44.6%) received a combination treatment of nimodipine with magnesium and 87 patients (55.4%) received only nimodipine. A matched case-control study using propensity scores was conducted and 41 subjects were selected from each group. A dosage of 64 mmol/day of magnesium was administrated.

RESULTS

The infusion of magnesium did not reduce the incidence of symptomatic cerebral vasospasm (n=7, 17.1%, p=0.29) compared with simple nimodipine injection (n=11, 26.8%). The ratios of good clinical outcome (modified Rankin scale 0-2) at 6 months were similar, being 78% in the combination treatment group and 80.5% in the nimodipine only group (p=0.79). The proportions of delayed cerebral infarction was not significantly lower in patients with combination treatment (n=2, 4.9% vs. n=3, 7.3%; p=0.64). There was no difference in the serum magnesium concentrations between the patients with symptomatic vasospasm and without vasospasm who had magnesium supplementation. No major complications associated with intravenous magnesium infusion were observed.

CONCLUSION

Magnesium supplementation (64 mmol/day) may not be beneficial for the reduction of the incidence of symptomatic cerebral vasospasm in patients with aneurysmal SAH.

Effect of silk fibroin peptide derived from silkworm Bombyx mori on the anti-inflammatory effect of Tat-SOD in a mice edema model

We investigated whether silk fibroin peptide derived from the silkworm, Bombyx mori, could inhibit inflammation and enhance the anti-inflammatory activity of Tat-superoxide dismutase (Tat-SOD), which was previously reported to effectively penetrate various cells and tissues and exert anti-oxidative activity in a mouse model of inflammation. Inflammation was induced by topical treatment of mouse ears with 12-O-tetradecanoylphorbol-13-acetate (TPA). Histological, Western blot, and reverse transcription-polymerase chain reaction data demonstrated that silk fibroin peptide or Tat-SOD alone could suppress elevated levels of cyclooxygenase-2, interleukin-6, interleukin-1beta, and tumor necrosis factor-alpha induced by TPA. Moreover, silk fibroin peptide significantly enhanced the anti-inflammatory activity of Tat-SOD, although it had no influence on in vitro and in vivo transduction of Tat-SOD. Silk fibroin peptide exhibited anti- inflammatory activity in a mice model of inflammation. Therefore, silk fibroin peptide alone or in combination with Tat-SOD might be used as a therapeutic agent for various inflammatory diseases.

Intraarterial tirofiban thrombolysis for thromboembolisms during coil embolization for ruptured intracranial aneurysms

OBJECTIVE

Thromboembolus can occur during endovascular coil embolization. The aim of our study was to show our experience of intraarterial (IA) tirofiban infusion for thromboembolism during coil embolization for ruptured intracranial aneurysms.

METHODS

This retrospective analysis was conducted in 64 patients with ruptured aneurysms who had emergent endovascular coil embolization from May 2007 to April 2011 at a single institute. Thromboembolic events were found in ten patients (15.6%). Anticoagulation treatment with intravenous heparin was started after the first coil deployment in ruptured aneurysmal sac. When a thrombus or embolus was found during the procedure, we tried to resolve them without delay with an initial dosage of 0.3 mg of tirofiban up to 1.2 mg.

RESULTS

Three patients of four with total occlusion had recanalizations of thrombolysis in myocardial infarction (TIMI) grade III and five of six with partial occlusion had TIMI grade III recanalizations. Eight patients showed good recovery, with modified Rankin Scale (mRS) score of 0 and one showed poor outcome (mRS 3 and 6). There was no hemorrhagic or hematologic complication.

CONCLUSION

IA tirofiban can be feasible when thromboembolic clots are found during coil embolization in order to get prompt recanalization, even in patients with subarachnoid hemorrhage.

Segmental artery injury following percutaneous vertebroplasty using extrapedicular approach

We performed a percutaneous vertebroplasty at the compressed L2 vertebral body of a 73-year-old female using a left-sided unilateral extrapedicular approach. She complained severe radiating pain and a tingling sensation in her left leg two hours after the vertebroplasty. Spinal computed tomographic scan showed a large retroperitoneal hematoma, and a subsequent spinal angiography revealed a left L2 segmental artery injury. Bleeding was successfully controlled by endovascular embolization. Recently, extrapedicular approaches have been attempted, allowing for the avoidance of facet and pedicle injury with only a unilateral approach. With this approach, however, the needle punctures the vertebral body directly. Therefore, this procedure carries the potential risk of a spinal segmental artery.