Full-endoscopic versus micro-endoscopic and open discectomy: A systematic review and meta-analysis of outcomes and complications

Enhanced technique of dural closure using autologous fat graft and Gelfoam for effective management of dural tear following interlaminar endoscopic lumbar spine surgery

BACKGROUND

Incidental dural tears are common complications in lumbar spine surgery, particularly in endoscopic procedures where primary closure via suturing is challenging. The absence of a standardized approach for dural closure in endoscopic spine surgery necessitates exploring alternative techniques.

OBJECTIVE

This study introduces a surgical technique for dural closure utilizing fat graft and Gelfoam, offering an effective alternative to standard approaches in endoscopic spine surgery.

METHODS

Surgical data from patients who underwent interlaminar endoscopic discectomy or stenosis decompression at Lerdsin Hospital from October 2014 to October 2021 were analyzed.

RESULTS

Among 393 cases, dural tears occurred in 2% (8 patients). Our technique achieved successful closure in all these cases, with no incidents of cerebrospinal fluid leakage or wound complications. The majority of patients showed favorable clinical outcomes, except for one case involving concomitant nerve root injury.

CONCLUSION

This study demonstrates that using fat graft and Gelfoam for dural closure is a simple, reliable, and safe technique, particularly effective for challenging-to-repair areas in interlaminar endoscopic lumbar spine surgery.

Enhancing Transforaminal Full Endoscopic Discectomy: Efficacy of the Hand Down Outside-In (HDOI) Technique

Endoscopic lumbar discectomy (ELD) is a key advancement in minimally invasive spinal surgery, particularly for lumbar disc herniation. Interlaminar endoscopic lumbar discectomy (IELD) and transforaminal endoscopic lumbar discectomy (TELD) are the two major methods used for FED. TELD, while less familiar to spine surgeons inexperienced in endoscopic surgery, presents challenges in visualizing the dura mater, a crucial aspect for reducing surgical complications. The hand down outside-in (HDOI) technique introduced by Dezawa enhances this visualization by positioning the cannula tip dorsally on the intervertebral disc and maneuvering it between the dura mater and disc to the spinal canal's midpoint. The cannula is then flipped to directly visualize the dura mater, enabling safe removal of the prolapsed disc material. A comparative study involving 20 patients treated from April 2020 to April 2022 examined the efficacy of the HDOI technique against conventional TELD. Each group, comprising ten patients, underwent ELD for lumbar disc herniation. While both groups showed similar improvements in clinical outcomes, as assessed using the Japanese Orthopedic Association (JOA) score and visual analogue scale (VAS) for pain, the HDOI group exhibited a 100% success rate for dura mater visualization, and this rate is significantly higher than the 60% observed in the conventional TELD group. Additionally, the time required for dura mater visualization was notably shorter for the HDOI technique. These results indicate that the HDOI technique not only enhances the safety and efficacy of TELD but may also encourage its wider use in clinical settings.

Ultrasound-guided erector spinae plane blocks for pain management after open lumbar laminectomy

PURPOSE

Lumbar spine surgery is associated with significant postoperative pain. The benefits of erector spinae plane blocks (ESPBs) combined with multimodal analgesia has not been adequately studied. We evaluated the analgesic effects of bilateral ESPBs as a component of multimodal analgesia after open lumbar laminectomy.

METHODS

Analgesic effects of preoperative, bilateral, ultrasound-guided ESPBs combined with standardized multimodal analgesia (n = 25) was compared with multimodal analgesia alone (n = 25) in patients undergoing one or two level open lumbar laminectomy. Other aspects of perioperative care were similar. The primary outcome measure was cumulative opioid consumption at 24 h. Secondary outcomes included opioid consumption, pain scores, and nausea and vomiting requiring antiemetics on arrival to the post-anesthesia care unit (PACU), at 24 h, 48 h, and 72 h after surgery, as well as duration of the PACU and hospital stay.

RESULTS

Opioid requirements at 24 h were significantly lower with ESPBs (31.9 ± 12.3 mg vs. 61.2 ± 29.9 mg, oral morphine equivalents). Pain scores were significantly lower with ESPBs in the PACU and through postoperative day two. Patients who received ESPBs required fewer postoperative antiemetic therapy (n = 3, 12%) compared to those without ESPBs (n = 12, 48%). Furthermore, PACU duration was significantly shorter with ESPBs (49.7 ± 9.5 vs. 79.9 ± 24.6 min).

CONCLUSIONS

Ultrasound-guided, bilateral ESPBs, when added to an optimal multimodal analgesia technique, reduce opioid consumption and pain scores, the need for antiemetic therapy, and the duration of stay in the PACU after one or two level open lumbar laminectomy.

Australian Spine Surgeon's Perspectives on Endoscopic Spine Surgery: An In-depth Analysis

OBJECTIVE

Endoscopic spine surgery (ESS) is a minimally invasive approach with reduced tissue trauma, shorter hospital stays, and faster recovery times. It employs advanced endoscopic instruments and imaging technologies to address a wide range of spinal pathologies with minimal disruption to surrounding tissues. As ESS continues to evolve, this article aims to gather insights into the opinions and perspectives of the key stakeholders involved, and highlight strategies to improve implementation.

METHODS

A cross-sectional survey was distributed to collect data on Australian spine surgeons' perspectives of ESS. The survey questionnaire was distributed electronically to a diverse group of spine surgeons who are members of the Spine Society of Australia.

RESULTS

Of responders, 46.8% were already integrating ESS into practice, or had the sufficient training to commence ESS. A further 29.8% were contemplating introduction of ESS techniques, while just under one quarter of respondents (23.4%) were not interested in implementing minimally invasive techniques. Primary motivators for implementation included skill development and improved patient outcomes. Primary barriers included lack of training opportunities, length of time to develop competency and lack of current supporting evidence.

CONCLUSION

The study contributes to the existing body of knowledge on ESS by providing a comprehensive analysis of surgeon opinions and experiences. The results highlight the growing interest in endoscopic techniques, while recognizing the challenges that need to be addressed to make this more widely utilised and available. The findings can guide future research, training programs, clinical practice and ultimately improve health and financial outcomes to patients and the wider health system.

Retrospective Study of Minimal Three-Year Follow-Up of Transforaminal Endoscopic Discectomy for Lumbar Disc Herniation: 5000 Multicenter Cases

Objective The objective of this study was to investigate the long-term effects of percutaneous transforaminal endoscopic lumbar discectomy (PTELD) and clarify the differences between outside-in and inside-out techniques. Methodology This was a multicenter retrospective study with a chart review of questionnaires about patients' quality of life. Patients were recruited from three hospitals in China. Based on certain inclusion and exclusion criteria, we enrolled in the study 5000 patients aged ≥18 years diagnosed with lumbar disc herniation who received PTELD from September 2015 to September 2019. The outside-in technique (n=2039) was compared with the inside-out technique for PTELD (n=1890) on the Visual Analogue Scale (VAS), Oswestry Disability Index (ODI), and the Short Form 36 (SF-36) of the Health Survey Questionnaire (physical component) both pre-operatively and post-operatively. Results VAS, ODI, and SF-36 significantly improved just after surgery for both techniques compared with pre-operative status. Nevertheless, significant differences existed between the two techniques concerning VAS for leg pain, VAS for back pain, ODI, and SF-36 at 0.5 months post-operatively. The above indices steadily improved within six months after both techniques, after which they did not significantly improve. In detail, outside-in patients suffered more back pain and worse ODI and SF-36 (physical) but had more relief from leg pain 0.5 months after surgery in terms of VAS. As for recovery rate from symptoms, there were only significant differences in recovery rate for leg pain and back pain at the first 1.5 months post-operatively. As for satisfaction rates, the outside-in technique had better results than the inside-out technique at both 0.5 months and 12 months. Conclusion Both techniques could relieve the symptoms of lumbar disc herniation. However, patients in the outside-in group suffered more back pain and a bigger risk of nerve injury than those in the inside-out group.

Intracranial Pressure Evaluation in Swine During Full-Endoscopic Lumbar Spine Surgery

BACKGROUND

Neurological complications during full-endoscopic spine surgery (FESS) might be attributed to intracranial pressure (ICP) increase due to continuous saline infusion (CSI). Understanding CSI and ICP correlation might modify irrigation pump usage. This study aimed to evaluate invasive ICP during interlaminar FESS; correlate ICP with irrigation pump parameters (IPPs); evaluate ICP during saline outflow occlusion, commonly used to control bleeding and improve the surgeon's view; and, after durotomy, simulate accidental dural tear.

METHODS

Five swine were monitored, submitted to total intravenous anesthesia, and positioned ventrally. A parenchymal catheter was installed through a skull burr for ICP monitoring. Lumbar interlaminar FESS was performed until exposure of neural structures. CSI was used within progressively higher IPPs (A [60 mm Hg, 350 mL/minute] to D [150 mm Hg, 700 mL/minute]), and ICP was documented. During each IPP, different situations were grouped: intact dura with open channels (A1-D1) or occlusion test (A2-D2); dural tear with open channels (Ax1-Dx1) or occlusion test (Ax2-Dx2). ICP <20 mm Hg was defined as safe.

RESULTS

Basal average ICP was 8.1 mm Hg. Adjustment in total intravenous anesthesia or suspension of tests was necessary due to critical ICP or animal discomfort. It was safe to operate with all IPPs with opened drainage channels (A1-D1) even with dural tear (Ax1-Dx1). Several occlusion tests (A2-D2, Ax2-Dx2) caused ICP increase (e.g., 86.1 mm Hg) influenced by anesthetic state and hemodynamics.

CONCLUSIONS

During FESS, CSI might critically raise ICP. Keeping drainage channels open, with ideal anesthetic state, ICP remains safe even with high IPPs, despite dural tear. Drainage occlusions can quickly raise ICP, being even more severe with higher IPPs. Total intravenous anesthesia may protect from ICP increase and may allow longer drainage occlusion or higher IPPs.

Anesthesia methods for full-endoscopic lumbar discectomy: a review

Full-endoscopic lumbar discectomy under local anesthesia is major trends for the treatment of lumbar disc herniation in spine minimally invasive surgery. However, sometimes local anesthesia is not enough for analgesic in surgery especially in interlaminar approach. This study summarizes the current study of anesthesia methods in full-endoscopic lumbar discectomy. Local anesthesia is still the most common anesthesia method in full-endoscopic lumbar discectomy and the comparison group for other anesthesia methods due to high safety. Compared to local anesthesia, Epidural anesthesia is less applied in full-endoscopic lumbar discectomy but reports better intraoperative pain control and equivalent safety due to the motor preservation and pain block characteristic of ropivacaine. General anesthesia can achieve totally pain block during surgery but nerve injury can not be ignored, and intraoperative neuromonitoring can assist. Regional anesthesia application is rare but also reports better anesthesia effects during surgery and equivalent safety. Anesthesia methods for full-endoscopic lumbar discectomy should be based on patient factors, surgical factors, and anesthesiologist factors to achieve satisfactory anesthesia experience and successful surgery.

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.

Development of an Endoscopic Spine Surgery Program: Overview and Basic Considerations for Implementation

Endoscopic spine surgery (ESS) is an innovative technique allowing for minimally invasive, direct visualization of spinal abnormalities. The growth of ESS in the United States has been stunted by high start-up costs, low reimbursement rates, and the steep learning curve associated with mastering endoscopic techniques. Hergrae, we describe the current state and future direction of ESS and provide key action items for ESS program implementation.

A 30-Year Worldwide Research Productivity of Scientific Publication in Full-Endoscopic Decompression Spine Surgery: Quantitative and Qualitative Analysis

Objective: The ever-growing number of articles related to full-endoscopic spine surgery published in the last few decades presents a challenge which is perplexing and time-consuming in identifying the current research status. The study aims to identify and analyze the most cited works related to full-endoscopic decompression spine surgery, compare the articles published by different publishers and area, and show the current publication status of full-endoscopic research.Methods: Using Bibliometrix, CiteSpace, and VOSviewer, we analyzed the bibliometric data selected from the Web of Science database between 1992 and 2022. Spine has the highest H-index with the most-cited journal in the field of full-endoscopic decompression spine surgery. China ranked as the most productive country, whereas the most cited with high H-index papers came from South Korea. For the author analysis, Yeung AT, Ruetten S, Hoogland T, Ahn Y, Choi G, and Mayer HM were the most impactful authors in the global and local citations. The most productive organization is Wooridul Spine Hospital.Conclusion: The bibliometric study showed a growing trend of research on full-endoscopic decompression spine surgery over the past 30 years. It has demonstrated that there is a significant increase in the number of authors, institutions, and internationally collaborated countries. However, the quality of studies is still low, and the lack of high-quality clinical evidence and the trend of general journal submissions has somewhat affected the quality of endoscopy journals in recent years.

Retrospective Case Control Study: Clinical and Computer Tomographic Fusion and Subsidence Evaluation for Single Level Uniportal Endoscopic Posterolateral Approach Transforaminal Lumbar Interbody Fusion Versus Microscopic Minimally Invasive Transforaminal Interbody Fusion

STUDY DESIGN

Retrospective comparative study.

OBJECTIVE

Assessment of difference in clinical and computer tomographic outcomes between the 2 cohorts.

METHODS

Computer tomographic evaluation by Bridwell's grade, Kim's stage, Kim's subsidence grade and clinical evaluation by VAS, ODI and McNab's criteria on both cohorts.

RESULTS

33 levels of Endo-TLIF and 22 levels of TLIF were included, with a mean follow up of 14.3 (10-24) and 22.9 (13-30) months respectively. Both Endo-TLIF and TLIF achieved significant improvement of pain and ODI at post-operative 4 week, 3 months and at final follow up with VAS 4.39 ± 0.92, 5.27 ± 1.16 and 5.73 ± 1.21in Endo-TLIF and 4.55 ± 1.16, 5.05 ± 1.11 and 5.50 ± 1.20 in TLIF respectively and ODI at post-operative 1 week, 3 months and final follow up were 43.15 ± 6.57, 49.27 ± 8.24 and 51.73 ± 9.09 in Endo-TLIF and 41.73 ± 7.98, 46.18± 8.46 and 49.09 ± 8.98 in TLIF respectively, P < 0.05. Compared to TLIF, Endo-TLIF achieved better VAS with 0.727 ± 0.235 at 3 months and 0.727 ± 0.252 at final follow up and better ODI with 3.88 ± 1.50 at 3months and 3.42 ± 1.63 at final follow up, P < 0.05. At 6 months radiological evaluation comparison of the Endo-TLIF and TLIF showed significant with more favorable fusion rate in Endo-TLIF of -0.61 ± 0.12 at 6 months and -0.49 ± 0.12 at 1 year in Bridwell's grading and 0.70 ± 0.15 at 6 months and 0.56 ± 0.14 at 1 year in Kim's stage.There is less subsidence of 0.606 ± 0.18 at 6 months and -0.561 ± 0.20 at 1 year of Kim's subsidence grade, P < 0.05.

CONCLUSION

Application of single level uniportal endoscopic posterolateral lumbar interbody fusion achieved better clinical outcomes and fusion rate with less subsidence than microscopic minimally invasive transforaminal lumbar interbody fusion in mid-term evaluation for our cohorts of patients.

Case-matched radiological and clinical outcome evaluation of interlaminar versus microsurgical decompression of lumbar spinal stenosis

PURPOSE

Endoscopic spine surgery is a globally expanding technique advocated as less invasive for spinal stenosis treatment compared to the microsurgical approach. However, evidence on the efficiency of interlaminar full-endoscopic decompression (FED) vs. conventional microsurgical decompression (MSD) in patients with lumbar spinal stenosis is still scarce. We conducted a case-matched comparison for treatment success with consideration of clinical, laboratory, and radiologic predictors.

METHODS

We included 88 consecutive patients (FED: 36/88, 40.9%; MSD: 52/88, 59.1%) presenting with lumbar central spinal stenosis. Surgery-related (operation time, complications, length of stay (LOS), American Society of Anesthesiologists physical status (ASA) score, C-reactive protein (CRP), white blood cell count, side of approach (unilateral/bilateral), patient-related outcome measures (PROMs) (Oswestry disability index (ODI), numeric rating scale of pain (NRS; leg-, back pain), EuroQol questionnaire (eQ-5D), core outcome measures index (COMI)), and radiological (dural sack cross-sectional area, Schizas score (SC), left and right lateral recess heights, and facet angles, respectively) parameters were extracted at different time points up to 1-year follow-up. The relationship of PROMs was analyzed using Spearman's rank correlation. Surgery-related outcome parameters were correlated with patient-centered and radiological outcomes utilizing a regression model to determine predictors for propensity score matching.

RESULTS

Complication (most often residual sensorimotor deficits and restenosis due to hematoma) rates were higher in the FED (33.3%) than MSD (13.5%) group (p < 0.05), while all complications in the FED group were observed within the first 20 FED patients. Operation time was higher in the FED, whereas LOS was higher in the MSD group. Age, SC, CRP revealed significant associations with PROMs. We did not observe significant differences in the endoscopic vs. microsurgical group in PROMs. The correlation between ODI and COMI was significantly high, and both were inversely correlated with eQ-5D, whereas the correlations of these PROMs with NRS findings were less pronounced.

CONCLUSIONS

Endoscopic treatment of lumbar spinal stenosis was similarly successful as the conventional microsurgical approach. Although FED was associated with higher complication rates in our single-center study experience, the distribution of complications indicated surgical learning curves to be the main factor of these findings. Future long-term prospective studies considering the surgical learning curve are warranted for reliable comparisons of these techniques.

Global research productivity in the field of discectomy on lumbar disc herniation: A systematic bibliometric analysis

Objective

To evaluate the global research productivity in the field of discectomy for lumbar disc herniation (LDH) through bibliometric analysis and mapping knowledge domains.

Methods

A systematic literature search was performed on the Web of Science (WoS), including the Science Citation Index Expanded (SCIE) database and PubMed. The number of publications, countries of publications, journals of publications, total citation frequency, impact factors of journals, and Institutional sources were analyzed by Microsoft Excel 2019, the Online Analysis Platform of Bibliometrics, and VOSviewer. Hotspots were also analyzed and visualized based on VOSviewer.

Results

A total of 2,066 papers were identified. The United States ranked first in the number of total citations (7,970). China ranked first in the number of publications (556, 26.9%), which has surpassed the United States in terms of the number of publications published annually since 2016. Wooridul Spine Hospital published the most papers (43). For journals, Spine has published the largest number of papers (289) in this field with the most citation frequencies (6,607). Hotspots could be divided into three clusters: surgery, lumbar disc herniation, and diagnoses. The most recent topic that appeared was symptomatic re-herniation.

Conclusions

The United States is the most significant contributor to the development of discectomy for LDH. The current research focus of discectomy on LDH was the comparison between surgical approaches and evaluation of current minimally invasive discectomy. At present, minimally invasive techniques, such as endoscopic discectomy, cannot completely replace non-endoscopic discectomy (open discectomy and microdiscectomy) through bibliometric analysis and mapping knowledge domains.

Postoperative Pain Management after Full Endoscopic Lumbar Discectomy: An Observational Study

Background: Surgical incision pain, rebound pain, and recurrence can manifest themselves in different forms of postoperative pain after full endoscopic lumbar discectomy (FELD). This study aims to evaluate various postoperative pains after FELD and summarize their characteristics. Methods: Data about the demographic characteristics of patients, pain intensity, and functional assessment results were collected from January 2016 to September 2019. Clinical outcomes including Oswestry Disability Index (ODI) and visual analog scale (VAS) scores, were obtained. Results: A total of 206 patients were enrolled. ODI and VAS of the patients significantly decreased after FELD at 12-month follow-up. A total of 193 (93.7%) patients had mild surgical incision pain after FELD and generally a VAS < 4, and it mostly resolved on its own within 3 days. A total of 12 (5.8%) patients experienced rebound pain, which was typically characterized by pain (mainly leg pain with or without back pain), generally occurring within 2 weeks after FELD and lasting < 3 weeks. The pain levels of rebound pain were equal to or less than those of preoperative pain, and generally scored a VAS of < 6. The recurrence rate was 4.4%. Recurrence often occurs within three months after surgery, with the pain level of the recurrence being greater than or equal to the preoperative pain. Conclusions: Different types of postoperative pain have their own unique characteristics and durations, and treatment options are also distinct. Conservative treatment and analgesia may be indicated for rebound pain and surgical incision pain, but recurrence usually requires surgical treatment.

Full-endoscopic versus conventional microsurgical therapy of lumbar disc herniation: a prospective, controlled, single-center, comprehensive cohort trial (FEMT-LDH trial)

BACKGROUND

Lumbar disc herniation is one of the leading causes of chronic low back pain. Surgery remains the therapy of choice when conservative approaches fail. Full-endoscopic approaches represent a promising alternative to the well-established microsurgical technique. However, high-grade evidence comparing these techniques is still scarce.

METHODS

Patients presenting with lumbar disc herniation will be included. The intervention group will obtain full-endoscopic disc decompression, whereas the control group will be treated by microsurgical disc decompression. We will apply a comprehensive cohort study design involving a randomized and a prospective non-randomized study arm. Patients who do not consent to be randomized will be assigned to the non-randomized arm. The primary outcome will be the Oswestry Disability Index (ODI). Secondary outcomes involve the visual analog scale (VAS) of pain and the SF-36 health questionnaire. Furthermore, clinical characteristics including duration of hospital stay, operation time, and complications as well as laboratory markers, such as C-reactive protein, white blood cell counts, and interleukin 6 will be determined and compared.

DISCUSSION

This study will significantly contribute to the current evidence available in the literature by evaluating the outcome of the full-endoscopic technique against the gold standard for lumbar disc herniation in a clinically relevant study setup. Additionally, the study design allows us to include patients not willing to be randomized in a prospective parallel study arm and to evaluate the impact of randomization on outcomes and include. The results could help to improve the future therapy in patients suffering from lumbar disc herniation.

TRIAL REGISTRATION

This study was prospectively registered in The German Clinical Trials Register (DRKS), a German WHO primary registry, under the registration number: DRKS00025786. Registered on July 7, 2021.

[Comparison of effectiveness of unilateral biportal endoscopy technique and the interlaminar uniportal endoscop technique for treatment of L 5, S 1 lumbar disc herniation]

Objective

To compare the effectiveness of unilateral biportal endoscopy (UBE) technique with the interlaminar uniportal endoscopy (IUE) technique for the treatment of L 5, S 1 lumbar disc herniation.

Methods

The clinical data of 69 patients with L 5, S 1 lumbar disc herniation who met the selection criteria between January 2020 and December 2020 were retrospectively analysed. The patients were divided into UBE group (30 cases) and IUE group (39 cases) according to endoscopic surgical technique. The general data, such as gender, age, body mass index, disease duration, and preoperative visual analogue scale (VAS) scores of low back/leg pain and Oswestry disability index (ODI), was not significantly different between the two groups ( P>0.05). Perioperative outcomes [estimated blood loss (EBL), total operation time, extracanal operation time, intracanal decompression time, intraoperative radiation exposure dose, incision length, operative related complications, and postoperative hospitalization stay] and clinical outcomes (VAS score of low back/leg pain before operation and at 3 days, 3 months, 6 months, and 12 months after operation as well as the ODI before operation and at 3 months, 6 months, and 12 months after operation) were recorded and compared between the two groups.

Results

All patients completed the surgery successfully. The incision length, EBL, and extracanal operation time in UBE group were significantly longer than those in IUE group ( P<0.05), and the intracanal decompression time in UBE group was significantly shorter than that in IUE group ( P<0.05). There was no significant difference in the total operation time, intraoperative radiation exposure dose, and postoperative hospitalization stay between the two groups ( P>0.05). Patients in both groups were followed up 12-15 months (mean, 13.3 months). Dural tear ocurred in 1 patient of the UBE group, and recurrence ocurred in 1 patient of the IUE group, the others of both groups had no surgery-related complications and recovered well after operation. The VAS scores of low back/leg pain and ODI in both groups at each time point after operation significantly improved when compared with those before operation ( P<0.05); there was no significant difference in VAS scores and ODI at each time point after operation between two groups ( P>0.05).

Conclusion

The effectiveness of UBE technique in the treatment of L 5, S 1 lumbar disc herniation is similar to that of IUE technique, and the efficiency of intraspinal operation is better than that of IUE technique. Although UBE technique is inferior to IUE technique in terms of surgical trauma, there is no significant difference in postoperative recovery between the two techniques.

The clinical efficacy of biportal endoscopy is comparable to that of uniportal endoscopy via the interlaminar approach for the treatment of L5/S1 lumbar disc herniation

Objective

To compare the clinical outcomes of unilateral biportal endoscopy/biportal endoscopic spinal surgery (UBE/BESS) via the posterior approach with those of interlaminar endoscopic lumbar discectomy (IELD) for the treatment of L5/S1 lumbar disc herniation.

Methods

We collected the clinical data of patients with L5/S1 lumbar disc herniation who had undergone endoscopic surgery at our center from January 2020 to July 2021, and 92 patients were included. They were divided into UBE/BESS (n = 42) and IELD (n = 50) groups. The incision length, operative time (overall operative, extracanal operative, and intracanal decompression times), intraoperative radiation exposure dose, changes in hemoglobin before and after surgery, postoperative hospital stay, visual analog scale (VAS) score for low back pain and leg, and Oswestry disability index (ODI) were statistically analyzed.

Results

One case incurred dural tear in the UBE/BESS group, and one case developed recurrence in the IELD group. Postoperatively, the VAS score and ODI index decreased significantly in both groups (P < 0.01). VAS and ODI scores (preoperative as well as 3 days, 3 months, 6 months, and 12 months after surgery), the overall operative time, and postoperative hospital stay were not significantly different between the two groups (P > 0.05). No statistical difference in intraoperative radiation exposure dose was noted between the two groups (P > 0.05). The surgical incision length was greater in the UBE/BESS group (P < 0.01), and pre- and postoperative hemoglobin changes were more pronounced in the UBE/BESS group (P < 0.01). The UBE/BESS group had a longer extracanal operative time and shorter intracanal decompression time (P < 0.01).

Conclusions

The clinical efficacy of UBE/BESS for L5/S1 lumbar disc herniation is comparable to that of IELD. Intraoperative radiation exposure doses were similar in both techniques. UBE/BESS required more time to identify tissue structures and a larger working space when operating outside the spinal canal; however, the efficiency of nucleus pulposus removal and nerve root release inside the spinal canal superseded that in IELD. Furthermore, the surgical incision in the UBE/BESS technique was longer, with greater actual blood loss during surgery, thus rendering UBE/BESS inferior to the IELD technique in terms of surgical trauma. Nonetheless, no significant difference was noted between the two techniques in the postoperative recovery time of patients.

Minimally invasive surgical management of symptomatic lumbar disc herniation: can the endoscope replace the microscope?

Background

Degenerative lumbar spine pathologies such as spinal stenosis and disc herniation constitute the most common causes of back pain and radiculopathy. After the introduction of the operative microscope in the 1970s, microscopic discectomy has become the gold standard of treatment for herniated lumbar disc by many surgeons. A tubular endoscopic approach was first described in 1997 by Foley and Smith as a new minimally invasive technique alternative to open surgical techniques. The objective of this study is to evaluate the outcome and efficacy of microscopic discectomy and endoscopic discectomy for the management of herniated lumbar disc as regard the clinical results, operation time, intraoperative blood loss, and postoperative complications.

Results

This is a retrospective study of 40 patients, with symptomatic lumbar disc herniation managed by the authors either by microscopic discectomy (MD) (n = 20) or by endoscopic discectomy (ED) (n = 20). Patients were followed up and postoperative data was recorded at 1, 6, 12 months after surgery. Clinical scoring systems included the Visual Analog Scale (VAS) for the preoperative and the postoperative low back ache (VAS-B) as well as preoperative and postoperative sciatic pain (VAS-S), in addition to the evaluation of the modified Japanese Orthopedic Association scale (mJOA) over the same time intervals. Significant postoperative improvement in clinical and functional outcome of the two groups was noted, including a statistically significant improvement in postoperative VAS-B and VAS-S as well as the mJOA scores in comparison to the preoperative data (p = 0.001). There was a statistically significant shorter operative time, less blood loss and less rate of operative complications recorded in the microscopic discectomy group as compared with endoscopic discectomy group in our study.

Conclusions

Our study concluded that microscopic lumbar discectomy is as safe and effective as endoscopic lumbar discectomy for the management of symptomatic lumbar disc herniation with a low complication rate, less operative blood loss and operative time. Larger series and further studies would be yet considered with longer follow-up periods.

Percutaneous Endoscopic Lumbar Discectomy Using a Double-Cannula Guide Tube for Large Lumbar Disc Herniation

Objective

To compare the effect of percutaneous endoscopic lumbar discectomy (PELD) using a double‐cannula guide tube (DGT), traditional PELD, and open lumbar discectomy (OLD) to treat large lumbar disc herniations (LLDHs).

Methods

Seventy patients who presented with LLDH without cauda equina syndrome and were treated with surgery in our hospital from October 2015 to October 2017 were included. The detailed index included the visual analog scale (VAS) for back and radicular leg pain and the Oswestry Disability Index (ODI) in the immediate preoperative period and at the final follow‐up. The operation time, radiation exposure time, surgical satisfaction rate, and modified MacNab criteria score were also recorded.

Results

The leg and back pain of the patients in these groups improved significantly in the postoperative period. No significant differences were observed in leg pain improvement between the other two groups; however, patients in the PELD group (with or without DGT) presented with significantly higher improvement in back pain than the OLD group (t = 9.965, p < 0.001). The final ODI scores were 12.1 ± 4.9, 11.2 ± 2.9, and 16.4 ± 3.6 in the PELD, PELD‐DGT, and OLD groups, respectively. Patients in the PELD and PELD‐DGT groups presented with significantly lower postoperative ODI scores than those in the OLD group (t = 20.834, p < 0.001). The mean postoperative hospital stays were significantly shorter in the PELD group and PELD with DGT group than in the OLD group (t = 46.688, p < 0.001). The mean operation time was significantly shorter in the PELD‐DGT group than those in the PELD group (t = 25.281, p = 0.001). No perioperative complications were observed in either group. Based on the modified MacNab criteria, excellent and good outcomes were achieved in 20 out of 21 patients (95.2%) in the PELD group, 23 out of 24 patients (95.8%) in the PELD‐DGT group, and 22 out of 25 patients (88.0%) in the OLD group. The rates of excellent and good outcomes were higher in the PELD and PELD‐DGT groups than in the OLD group, but there were no significant differences (χ² = 1.454, p = 0.835).

Conclusions

PELD using DGT is a safe and effective option for LLDH and features advantages such as improvements in back pain, a lower hospitalization cost than OLD, a shorter operation time, and less fluoroscopy than traditional PELD.

Intradiscal oxygen-ozone chemonucleolysis versus microdiscectomy for lumbar disc herniation radiculopathy: a non-inferiority randomized control trial

BACKGROUND CONTEXT

Low back pain with or without radicular leg pain is an extremely common health condition significantly impacting patient's activities and quality of life. When conservative management fails, epidural injections providing only temporary relief, are frequently utilized. Intradiscal oxygen-ozone may offer an alternative to epidural injections and further reduce the need for microdiscectomy.

PURPOSE

To compare the non-inferiority treatment status and clinical outcomes of intradiscal oxygen-ozone with microdiscectomy in patients with refractory radicular leg pain due to single-level contained lumbar disc herniations.

STUDY DESIGN / SETTING

Multicenter pilot prospective non-inferiority blocked randomized control trial conducted in three European hospital spine centers.

PATIENT SAMPLE

Forty-nine patients (mean 40 years of age, 17 females/32 males) with a single-level contained lumbar disc herniation, radicular leg pain for more than six weeks, and resistant to medical management were randomized, 25 to intradiscal oxygen-ozone and 24 to microdiscectomy. 88% (43 of 49) received their assigned treatment and constituted the AS-Treated (AT) population.

OUTCOME MEASURES

Primary outcome was overall 6-month improvement over baseline in leg pain. Other validated clinical outcomes, including back numerical rating pain scores (NRS), Roland Morris Disability Index (RMDI) and EQ-5D, were collected at baseline, 1 week, 1-, 3-, and 6-months. Procedural technical outcomes were recorded and adverse events were evaluated at all follow-up intervals.

METHODS

Oxygen-ozone treatment performed as outpatient day surgeries, included a one-time intradiscal injection delivered at a concentration of 35±3 μg/cc of oxygen-ozone by a calibrated delivery system. Discectomies performed as open microdiscectomy inpatient surgeries, were without spinal instrumentation, and not as subtotal microdiscectomies. Primary analyses with a non-inferiority margin of -1.94-point difference in 6-month cumulative weighted mean leg pain NRS scores were conducted using As-Treated (AT) and Intent-to-Treat (ITT) populations. In post hoc analyses, differences between treatment groups in improvement over baseline were compared at each follow-up visit, using baseline leg pain as a covariate.

RESULTS

In the primary analysis, the overall 6-month difference between treatment groups in leg pain improvement using the AT population was -0.31 (SE, 0.84) points in favor of microdiscectomy and using the ITT population, the difference was 0.32 (SE, 0.88) points in favor of oxygen-ozone. The difference between oxygen-ozone and microdiscectomy did not exceed the non-inferiority 95% confidence lower limit of treatment difference in either the AT (95% lower limit, -1.72) or ITT (95% lower limit, -1.13) populations. Both treatments resulted in rapid and statistically significant improvements over baseline in leg pain, back pain, RMDI, and EQ-5D that persisted in follow-up. Between group differences were not significant for any outcomes. During 6-month follow-up, 71% (17 of 24) of patients receiving oxygen-ozone, avoided microdiscectomy. The mean procedure time for oxygen-ozone was significantly faster than microdiscectomy by 58 minutes (p<.0010) and the mean discharge time from procedure was significantly shorter for the oxygen-ozone procedure (4.3±2.9 hours vs. 44.2±29.9 hours, p<.001). No major adverse events occurred in either treatment group.

CONCLUSIONS

Intradiscal oxygen-ozone chemonucleolysis for single-level lumbar disc herniations unresponsive to medical management, met the non-inferiority criteria to microdiscectomy on 6-month mean leg pain improvement. Both treatment groups achieved similar rapid significant clinical improvements that persisted and overall, 71% undergoing intradiscal oxygen-ozone were able to avoid surgery.

Comparison of Endoscopic Discectomy Versus Non-Endoscopic Discectomy for Symptomatic Lumbar Disc Herniation: A Systematic Review and Meta-Analysis

STUDY DESIGN

Systematic review.

OBJECTIVE

The authors aimed to systematically compare the effectiveness and safety of endoscopic discectomy (ED) with non-endoscopic discectomy (NED) for treatment of symptomatic lumbar disc herniation (LDH).

METHODS

A systematic search was performed on PubMed, EMBASE, the Cochrane Library and China National Knowledge Infrastructure for randomized controlled trial from inception until August 13, 2020. Trials which investigated multiple operative approaches on lumbar disc herniation were identified without language restrictions.

RESULTS

In total, 25 trials involving 2258 patients with symptomatic LDH were included. Twenty trials performed the comparison between ED and NED. Five trials performed the comparison between percutaneous endoscopic transforaminal discectomy (PETD) and percutaneous endoscopic interlaminar discectomy (PEID). The operative time of micro-endoscopic discectomy (MED) was longer than open discectomy (OD). The length of hospital stay of percutaneous endoscopic lumbar discectomy (PELD) was shorter than fenestration discectomy (FD). Significant differences in intraoperative blood loss volumes were found between PELD with FD and MED with OD. The complication rate of PELD was lower than FD (PELD: 4.3%; FD: 14.6%) and the complication rate of full-endoscopic discectomy (FE) was lower than microscopic discectomy (MD) (FE: 13.4%; MD: 32.1%).

CONCLUSIONS

PELD and FE have the advantage of limiting intraoperative damages. ED and NED can be both considered sufficient to achieve good clinical outcomes. PETD and PEID are able to achieve similar results but the learning curve of PETD was steeper. More independent high-quality RCTs with sufficiently large sample sizes performing cost-effectiveness analyzes are needed.

Percutaneous Endoscopic Lumbar Discectomy for Recurrent Lumbar Disc Herniation: An Updated Systematic Review and Meta-Analysis

OBJECTIVE

This meta-analysis evaluated surgical outcomes following endoscopic or conventional discectomy for recurrent lumbar disc herniation.

METHODS

Medline, Cochrane, EMBASE, and Google Scholar were search until October 16, 2016 using these terms: recurrent lumbar disc herniation, endoscopic surgery, and discectomy. Randomized controlled trials (RCTs), prospective, retrospective, and cohort studies were eligible for inclusion. Pooled difference in mean (PDM) with 95% confidence interval (CIs) or relative risks (RRs) were calculated using fixed-effects methods.

RESULTS

One RCT and 15 studies were included with a total of 820 patients. Patients received endoscopic surgery experienced shorter operation time than those received conventional surgery (PDM: -52.01, 95% CI: -76.84 to -27.18, P < 0.001). A significantly lower risk in complication was displayed in patients received endoscopic surgery compared to those received conventional surgery (RR: 0.209, 95% CI: 0.076-0.581, P = 0.003). No significant difference in the improvement in VAS (PDM: -2.19, 95% CI: -5.78 to 1.39, P = 0.231), length of stay (PDM: -6.44, 95% CI: -13.76 to 0.89, P = 0.085) and re-recurrence rate (PDM: 0.88, 95% CI: 0.22-3.50, P = 0.861) between groups.

CONCLUSIONS

Endoscopic and conventional discectomy reduced patient pain comparably, but endoscopic discectomy had significantly lower operation time and lower risk in complications, which may impact other outcomes such as recovery and healthcare costs. More studies are needed to confirm our findings.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s43465-022-00636-1.

Surgeons’ Perspective, Learning Curve, Motivation, and Obstacles of Full-Endoscopic Spine Surgery in Thailand: Results From A Nationwide Survey

Objective

To report a nationwide survey of the endoscopic spine surgeons across Thailand. Furthermore, the survey will be focused on the perspective of experience, learning curve, motivations, and obstacles at the beginning of their practices.

Materials and Methods

The online survey consisting of 16 items was distributed to spine surgeons who are performing endoscopic spine surgery in Thailand via the Google forms web-based questionnaire to investigate participants' demographics, backgrounds, experience in endoscopic spine surgery, motivations, obstacles, and future perspectives. The data was recorded from January 7, 2020 to January 21, 2022. Descriptive statistics were used for analysis.

Results

A total of 42 surveys were submitted by 6 neurosurgeons (14.3%) and 36 orthopedic surgeons (85.7%). From the surgeons' perspective, the average number of cases that should be performed until one feels confident, consistently good outcomes, and has minimal complications was 27.44 ± 32.46 cases. For surgeons who starting the endoscopic spine practice, at least 3 workshop participation is needed. Personal interest (39 selected responses) and trending marketing or business purpose (25 selected responses) were the primary motivators for endoscopic spine surgery implementation. Lack of support (18 selected responses) and afraid of complications (16 selected responses) were pertinent obstacles to endoscopic spine surgery implementation.

Conclusions

The trend of endoscopic spine surgery has continued to grow in Thailand, shown by the rate of implementation of endoscopic spine surgery reported by Thai spine surgeons. The number of appropriate cases until one feels confident was around 28 cases. The primary motivator and obstacles were personal interest and lack of support.

Risk Factors and Surgical Management of Recurrent Herniation after Full-Endoscopic Lumbar Discectomy Using Interlaminar Approach

Full-endoscopic lumbar discectomy (FED) is one of the least invasive procedures for lumbar disc herniation. Patients who receive FED for lumbar disc herniation may develop recurrent herniation at a frequency similar to conventional procedures. Reoperation and risk factors of recurrent lumbar disc herniation were investigated among 909 patients who received FED using an interlaminar approach (FED-IL). Sixty-five of the 909 patients received reoperation for recurrent herniation. Disc height, smoking, diabetes mellitus (DM), subligamentous extrusion (SE) type, and Modic change were identified as the risk factors for recurrence. Other indicators such as LL, Cobb angle, disc migration, age, sex, and body mass index (BMI) did not reach significance. Among 65 patients, reoperation was performed within 14 days following FED-IL (very early) in 7 patients, from 15 days to 3 months (early) in 14 patients, from 3 months to 1 year (midterm) in 17 patients, and after more than 1 year (late) in 27 patients. The very early group included a greater number of males, and the mean age was significantly lower in comparison to other groups. All patients in the very early group received FED-IL for reoperation. Reoperation within 2 weeks allows FED-IL to be performed without adhesion. Fusion surgery was performed on three cases in the early and midterm groups and on 10 cases in the late group, which increased over time as degenerative change and adhesion progressed. The procedure selected to treat recurrent herniation mostly depends on the surgeon’s preference. Revision FED-IL is the first choice for recurrent herniation in terms of minimizing surgical burden, whereas fusion surgery offers the advantage that discectomy can be performed through unscarred tissues. FED-IL is recommended for recurrent herniation within 2 weeks before adhesion progresses.

Differential characterization of lumbar spine associated tissue histology with nonlinear optical microscopy

Percutaneous endoscopic lumbar discectomy (PELD) is the major effective treatment for lumbar disc herniation, and rapid histological identification of dissected tissue is critical to guide the discectomy. In this work, we revealed the histological features of different types of peridural tissues of the lumbar spine by label-free multi-modal nonlinear optical microscopy. Stimulated Raman scattering (SRS) was used to extract lipid and protein distributions, while second harmonic generation (SHG) and two-photon excited fluorescence (TPEF) signals were applied to image the collagen and elastin fibers at the same time. Our results demonstrated that the nonlinear optical features of the dura and adjacent soft tissues were significantly different, showing the potentials of our method for intraoperative differentiation of these critical tissues and improving the surgical outcome of PELD.

Evaluation of Two Methods (Inside-Out/Outside-In) Inferior Articular Process Resection for Uniportal Full Endoscopic Posterolateral Transforaminal Lumbar Interbody Fusion: Technical Note

Objective: There is limited literature comparing the uniportal full endoscopic posterolateral transforaminal lumbar interbody fusion outside-in approach (ETLIF (O)) with the inside-out approach (ETLIF (I)). Methods: Radiological evaluation was performed on disc height restoration and coronal wedging angle, and operation time (inferior articular process resection time/total operation time) and clinical evaluation were made. Result: 48 cases of inside-out and 38 cases of outside-in cases were included. Compared to inside-out, the outside-in approach had significantly less operative time required to resect inferior articular process: 36.55 ± 10.37, and total operative time: 87.45 ± 20.14 min compared to 49.83 ± 23.97 and 102.56 ± 36.53 min, respectively, for the inside-out approach, p < 0.05. Compared to the preoperative state, both cohorts achieved significant improvement of VAS and ODI at post-operative 1 week, 3 months and at final follow up. Both cohorts achieved statistically significant increased disc height with 5.00 ± 2.87 mm, 5.49 ± 2.33 mm and statistically significant improvement in coronal wedge angle with 1.76 ± 1.63°, 3.24 ± 2.92° in the inside-out and outside-in approaches respectively. Conclusions: Complete removal of inferior articular process is the key part of endoscopic fusion with two methods that can be applied: an inside-out approach or an outside-in approach. Comparing both techniques, the outside-in approach has a shorter operative time required for inferior articular process resection and total length of operation with similar good clinical and radiological outcomes.

Comparison of post-operative wound pain between interlaminar and transforaminal endoscopic spine surgery: which is superior?

STUDY DESIGN

Prospective cohort study PURPOSE: The objective is to compare post-operative wound pain in patients treated by endoscopic surgery between interlaminar and transforaminal approach at lumbar region.

OVERVIEW OF LITERATURE

There are two common approaches for endoscopic lumbar spine surgery, interlaminar and transforaminal approach. The wound size of these two approaches is about the same. However, post-operative wound pain may differ according to the entrance area.

METHODS

We conducted a prospectively cohort study including all patients underwent full endoscopic lumbar spine surgery by single surgeon between January 2016 to October 2019. Wound pain using visual analog scale (VAS) at post-operative day 1 and day 14 were collected. VAS back pain, VAS leg pain, Oswestry Disability Index (ODI), modified McNab criteria and complications were also collected.

RESULTS

There were 313 patients included in the study. There was no significant difference in VAS wound pain between interlaminar and transforaminal group. Interestingly, subgroup analysis in interlaminar group found statistically significant higher VAS for wound pain at post-operative day 1 when significant bone resection was done by power burr. VAS back-leg pain and ODI have improved significantly between pre-operative and last follow up in both approaches.

CONCLUSIONS

Wound pain from endoscopic spine surgery is minimal. This study found no difference in wound pain between endoscopic interlaminar and transforaminal approach. Both approaches show favorable clinical outcomes with few serious complications rate. Further study with long term follow up is needed.

Development and validation of a nomogram predicting the risk of recurrent lumbar disk herniation within 6 months after percutaneous endoscopic lumbar discectomy

OBJECTIVE

To develop and validate a nomogram useful in predicting recurrent lumbar disk herniation (rLDH) within 6 months after percutaneous endoscopic lumbar discectomy (PELD).

METHODS

Information on patients' lumbar disk herniation (LDH) between January 2018 and May 2019 in addition to 26 other features was collected from the authors' hospital. The least absolute shrinkage and selection operator (LASSO) method was used to select the most important risk factors. Moreover, a nomogram was used to build a prediction model using the risk factors selected from LASSO regression. The concordance index (C-index), the receiver operating characteristic (ROC) curve, and calibration curve were used to assess the performance of the model. Finally, clinical usefulness of the nomogram was analyzed using the decision curve and bootstrapping used for internal validation.

RESULTS

Totally, 352 LDH patients were included into this study. Thirty-two patients had recurrence within 6 months while 320 showed no recurrence. Four potential factors, the course of disease, Pfirrmann grade, Modic change, and migration grade, were selected according to the LASSO regression model. Additionally, the C-index of the prediction nomogram was 0.813 (95% CI, 0.726-0.900) and the area under receiver operating characteristic curve (AUC) value was 0.798 while the interval bootstrapping validation C-index was 0.743. Hence, the nomogram might be a good predictive model.

CONCLUSION

Each variable, the course of disease, Pfirrmann grade, Modic change, and migration grade in the nomogram had a quantitatively corresponding risk score, which can be used in predicting the overall recurrence rate of rLDH within 6 months.

Learning curve of percutaneous endoscopic transforaminal lumbar discectomy by a single surgeon

To evaluate the learning curve of percutaneous endoscopic transforaminal lumbar discectomy (PETLD) from the novice stage to the proficient stage, we performed retrospective study for patients with lumbar disc herniation who underwent PETLD performed by a single surgeon and evaluated the surgeon's learning curve and the effect of surgical proficiency on outcomes.A total of 48 patients who underwent PETLD at the lower lumbar level (L3-S1) with a minimum 1-year follow-up were enrolled. The learning curve of the surgeon was assessed using cumulative study of operation time and linear regression analyses to reveal the correlation between operation time and case series number.Because the cutoff of familiarity was 25 cases according to the cumulative study of operation time, the patients were allocated into two groups: early group (n = 25) and late group (n = 23). The clinical, surgical, and radiological outcomes were retrospectively evaluated and compared between the two groups.According to linear regression analyses, the operation time was obtained using the following formula: operation time (minutes) = 69.925-(0.503 × [case number]) (P < .001).As expected, the operation time was significantly different between the two groups (mean 66.00 ± 11.37 min in the early group vs 50.43 ± 7.52 min in the late group, P < .001). No differences were found between the two groups in demographic data and baseline characteristics. Almost all clinical outcomes (including pain improvement and patient satisfaction), surgical outcomes (including failure, recurrence, and additional procedure rates), and radiological outcomes (including change of disc height and sagittal angles) did not differ between the two groups.However, the late group demonstrated a more favorable postoperative volume index of the remnant disc (362.91 mm3 [95% confidence interval, 272.81-453.02] in the early group vs 161.14 mm3 [95% confidence interval, 124.31-197.97] in the late group, P < .001), and a lower complication rate related to exiting nerve root (16.0% in the early group vs 0% in the late group, P = .045).The learning curve of PETLD is not as difficult as that of other minimally invasive spine surgery technique. Although the overall outcomes were not different between the groups, the risks of incomplete decompression and exiting root injury-related complication were higher in the novice stage.

Learning curve of trans-sacral epiduroscopic laser decompression in herniated lumbar disc disease

BACKGROUND

Trans-sacral epiduroscopic laser decompression (SELD) using slender epiduroscope and a holmium YAG laser is one of the minimally invasive surgical options for lumbar disc herniation. However, the learning curve of SELD and the effect of surgical proficiency on clinical outcome have not yet been established. We investigated patients with lumbar disc herniation undergoing SELD to report the clinical outcome and learning curve.

METHODS

Retrospective analysis of clinical outcome and learning curve were performed at a single center from clinical data collected from November 2015 to November 2018. A total of 82 patients who underwent single-level SELD for lumbar disc herniation with a minimum follow-up of 6.0 months were enrolled. Based on the findings that the cut-off of familiarity was 20 cases according to the cumulative study of operation time, patients were allocated to two groups: early group (n = 20) and late group (n = 62). The surgical, clinical, and radiological outcomes were retrospectively evaluated between the two groups to analyze the learning curve of SELD.

RESULTS

According to linear and log regression analyses, the operation time was obtained by the formula: operation time = 58.825-(0.181 × [case number]) (p < 0.001). The mean operation time was significantly different between the two groups (mean 56.95 min; 95% confidence interval [CI], 49.12-64.78 in the early group versus mean 45.34 min; 95% CI, 42.45-48.22 in the late group; p = 0.008, non-parametric Mann-Whitney U test). Baseline characteristics, including demographic data, clinical factors, and findings of preoperative magnetic resonance imaging, did not differ between the two groups. Also, there was no significant difference in terms of surgical outcomes, including complication and failure rates, as well as clinical and radiological outcomes between the two groups.

CONCLUSION

The learning curve of SELD was not as steep as that of other minimally invasive spinal surgery techniques, and the experience of surgery was not an influencing factor for outcome variation.

Comparative Study between Full-Endoscopic Discectomy and Microendoscopic Discectomy for the Treatment of Lumbar Disc Herniation

Background and objectives: Lumbar disc herniation (LDH) is a common disease in the meridian of life. Although surgical discectomy is commonly used to treat LDH, there are several different strategies. We compared the outcomes of uniportal full-endoscopic discectomy (FED) with those of microendoscopic discectomy (MED) in treating LDH. Materials and Methods: FED was performed using a 4.1-mm working channel endoscope, and MED was performed using a 16-mm diameter tubular retractor and endoscope. Data of patients with LDH treated with FED (n = 39) or MED (n = 27) by the single surgeon were retrospectively reviewed. Patient background information and operative data were collected. Pre- and postoperative low back and leg pain were evaluated using the numerical rating scale (NRS) score. Pre- and postoperative disc height index (DHI) values were calculated from plain radiographs, and the disc height loss was evaluated using the ratio (DHI ratio); Results: The median (interquartile range (IQR) Q25–75) operation times for FED and MED were 42 (33–61) and 43 (33–50) minutes, respectively. The median (IQR Q25–75) pre- and postoperative NRS scores for low back pain were 5 (2–7) and 1 (0–4), respectively, for FED and 6 (3–8) and 1 (0–2), respectively, for MED. The median (IQR Q25–75) pre- and postoperative NRS scores for leg pain were 7 (5–8) and 0 (0–2), respectively, for FED and 6 (5–8) and 0 (0–2), respectively, for MED. These data were not different between the FED and MED groups. The median (IQR Q25–75) DHI ratios of FED and MED were 0.94 (0.89–1.03) and 0.90 (0.79–0.95), respectively. The DHI ratio was significantly higher (p < 0.05) in the FED group than in the MED group, and there was less blood loss; Conclusions: The pain-relieving effect of FED in treating LDH was almost identical to that of MED. However, FED was superior to MED in preventing disc height loss, which is one of the indicators of postoperative disc degeneration.

Clinical Anatomy and Possible Clinical Significance of the Postcentral Branches of Spinal Arteries in the L1-L5 Levels

STUDY DESIGN

This was a dissection-based study of 10 embalmed human cadavers.

OBJECTIVE

The objective of this study was to identify and describe the postcentral branches in the L1-L5 intervertebral foramina (IVF) and to determine their possible clinical significance.

SUMMARY OF BACKGROUND DATA

The lower lumbar segmental arteries have been well studied. However, there are few articles with regard to the postcentral branches in the L1-L5 IVF.

MATERIALS AND METHODS

Eighty L1-L5 IVF from 10 embalmed cadavers were studied with a surgical microscope, and the postcentral branches were identified. The branches, origin, insertion, and spatial orientation of the postcentral branches in the L1-L5 IVF were examined. The diameter of the arteries was measured using a Vernier caliper.

RESULTS

In our study, the occurrence rate of a postcentral branch was 100.00% in the 80 IVFs. The postcentral branch was routinely divided into the following 2 types: type 1, postcentral branch main trunks (65.00%), which branch from the spinal arteries or lumbar arteries and then divide into 2 branches (superior and inferior branches), and type 2, superior and inferior branches, which branch straight from the spinal arteries (35.00%). The initial portion of the postcentral branches traveled around the anterolateral edge of the disk to the dorsum.

CONCLUSIONS

Postcentral branches of spinal arteries are common structures in IVF; there are 2 types of postcentral branches. Thorough understanding of the spinal arteries before percutaneous endoscopic lumbar discectomy may be an important step in reducing intraoperative bleeding and ensuring clear visualization, which may result in significant benefits for patients.

Successful Introduction of Full-Endoscopic Lumbar Interlaminar Discectomy in Sweden

BACKGROUND

The introduction of full-endoscopic lumbar discectomy (FELD) procedures has made it possible to challenge microscopic discectomy as the gold standard method to treat lumbar disc herniations.

PURPOSE

The aim of the present study is to investigate the introductory-phase postoperative clinical improvement for FELD patients regarding leg pain, patient-reported outcome measurements (PROMs), complications, reoperations, and learning curve analysis.

METHODS

All patients who underwent FELD at Sahlgrenska University Hospital, Sweden, were prospectively included during 2013- 2017. A total of 92 patients were enrolled and followed up for 1 year. The characteristics of the study population, degree of leg pain, complications, learning curve, and PROMs were retrieved from patient records and the National Quality Register for Spine Surgery (Swespine).

RESULTS

The postoperative results demonstrated major improvements; leg pain measured by a numerical rating scale (0-10) decreased from 7.4 ± 2.25 to 2.76 ± 2.70, with a mean improvement of -4.54, (-3.62-5.46) 95% confidence interval (CI). The Oswestry Disability Index decreased by 30.48 (-36.27-23.73) with a 95% CI, and the EuroQol-5D increased by 0.39 (0.21-0.57) 95% CI. An assessment of the final surgical result showed that 91.6% ranked their general situation as better or much better. Specifically, regarding postoperative leg pain, 87% regarded their leg pain as completely gone, much better, or somewhat better, while 13% regarded their leg pain as unchanged or worse. A learning curve analysis showed that for every 10th FELD procedure performed; the duration of surgery decreased by 2 minutes.

CONCLUSIONS

In our study, the introduction of FELD as a safe, quick procedure for the treatment of lumbar disc herniations can yield significant gains in patient-reported outcome measurements and pain reduction. The rate of recurrence and complications is comparable to that of standard surgery.

Functional Evolution after Percutaneous Endoscopic Lumbar Discectomy, an Earlier Evaluation of 32 Cases

Objective  To determine time period for hospital discharge and pain and function improvement in patients submitted to percutaneous endoscopic lumbar discectomy (PELD).

Methods  Retrospective evaluation of length of stay and visual analog scale (VAS), Oswestry disability index (ODI), and Roland-Morris questionnaire results in 32 patients undergoing PELD at the preoperative period and at 2 days and 1, 2, 4, 6 and 12 postoperative weeks.

Results  All patients were discharged in less than 6 hours. There was a statistically significant improvement between the results obtained before the procedure and 2 days postsurgery: the mean VAS for axial pain went from 6.63 to 3.31, the VAS for irradiated pain went from 6.66 to 2.75, the Oswestry score went from 44.59 to 33.17%, and the Roland-Morris score went from 14.03 to 10.34. This difference progressively improved up to 12 weeks in all questionnaires. Regarding the Oswestry score, minimum disability values (19.39%) were observed at 6 weeks.

Conclusion  All 32 patients were discharged within 6 hours. Pain and function improved significantly after 48 hours, with further significant and progressive improvement until the 3 ^rd month.

A randomized study protocol of microendoscopic versus open discectomy in treatment of lumbar disc herniation

BACKGROUND

Lumbar disk herniation (LDH) is one of the main causes of discogenic low back pain. However, the evidence comparing different approaches for discectomy has lacked definitive conclusions, with conflicting results regarding the benefit of minimally invasive versus open techniques for LDH. We are now conducting a randomized controlled trial to figure out whether or not microendoscopic discectomy yields better clinical outcomes and causes less surgical trauma than open surgery.

METHODS

This prospective, randomized, single-blind, controlled, superiority clinical trial was approved by the institutional review board in the People's Hospital of Jianyang City. The conduct of this study followed the Declaration of Helsinki principles and the reporting of this study adhered to the Consolidated Standards of Reporting Trials guidelines for randomized controlled trials. Subjects were randomized into 2 groups as follows: open surgery and microendoscopic group. The outcomes included pain score, functional outcome, satisfaction rate, radiological outcomes, and complications. The statistical analyses in this study were performed using the Statistical Package for the Social Sciences 20.0 software. P < .05 was accepted as statistically significant.

RESULTS

The hypothesis was that the open technique would achieve similar clinical outcomes as compared to the microendoscopic technique in LDH.

TRIAL REGISTRATION

This study protocol was registered in Research Registry (researchregistry5708).

Lumbar Endoscopic Unilateral Laminotomy for Bilateral Decompression Outside-In Approach: A Proctorship Guideline With 12 Steps of Effectiveness and Safety

Minimally invasive spinal surgery in particular lumbar endoscopic unilateral laminotomy with bilateral decompression becomes popular as it can be performed with regional anesthesia, soft tissue damages are minimized as endoscopic visualization and instruments can be brought close to operating area bypassing much of the intervening soft tissues for sufficient spinal decompression with ligamentum flavum resection despite less bony resection compared to open surgery. Overall, when well executed, it preserves spinal stability. Outside-in technique of decompression is also known as over the top decompression in minimally invasive literature. It involves maintaining deep layer of ligamentum flavum integrity till satisfactory bony decompression is achieved. Deep layer of ligamentum flavum is removed as final step of decompression. Preservation of the deep layer of ligamentum flavum protects the neural elements, allowing drills and sharp equipment to be used safely to perform bony decompression.In this study, we demonstrate the technical details of outside-in approach lumbar endoscopic unilateral laminotomy with bilateral decompression (LE-ULBD). LE-ULBD Outside-in Technique is an effective and safe procedure in relieving lumbar spinal stenosis with favorable results with a follow-up for more than 1 year.

Learning curve of percutaneous endoscopic interlaminar lumbar discectomy versus open lumbar microdiscectomy at the L5-S1 level

Objective

Many studies on the clinical outcome of full endoscopic spine surgery versus open spine surgery have been published. However, only a few studies have compared the learning curves of percutaneous endoscopic interlaminar lumbar discectomy (PEILD) and open lumbar microdiscectomy (OLM) at the L5–S1 level. This study included patients with disc herniation at the L5–S1 level, who underwent PEILD or OLM performed by a single novice surgeon and compared the learning curves.

Methods

Fifty-six patients who underwent PEILD or OLM at the L5–S1 level and completed a minimum 1-year follow-up were enrolled in the study. The patients were allocated to the PEILD group (n = 27, September 2014 to August 2016) or an OLM group (n = 29, September 2012 to August 2014). The learning curves were retrospectively compared based on operation time and surgical outcomes, including complication, failure, and recurrence rates were retrospectively compared.

Results

Significant intergroup differences were not noted with respect to the baseline characteristics, including age, sex, body mass index, preoperative symptoms, or preoperative radiological findings. The mean operation time was significantly shorter in the PEILD group than in the OLM group (63.89±17.99 min versus 78.03±19.01 min, p = 0.006). Based on the operation time according to the number of cases, the learning curve was more difficult in the PEILD group according to the cumulative analysis (case number cut-off for proficiency was 18 in the PEILD group versus 10 in the OLM group) and linear regression analysis (proportionality constant for decrease in the operation time was -0.922 in the PEILD group versus -1.738 in the OLM group) than that in the OLM group. However, the surgical outcomes, including failure, surgical efficacy based on nerve root decompression, complication, and recurrence rates did not differ between the two groups.

Conclusion

Although the learning curve of PEILD was more difficult than that of OLM, the mean operation time was shorter in the PEILD group than that in the OLM group. Moreover, based on the surgical outcomes, PEILD showed efficacy and safety similar to those of OLM.

Technical Considerations of Uniportal Endoscopic Posterolateral Lumbar Interbody Fusion: A Review of Its Early Clinical Results in Application in Adult Degenerative Scoliosis

BACKGROUND

Uniportal endoscopic posterolateral lumbar interbody fusion (Endo-TLIF) provides one of the least invasive forms of minimally invasive surgery, allowing large size cages which are commercially available for open and tubular microscopic transforaminal lumbar interbody fusion (TLIF) to be inserted through this approach. We studied the effect of such a technique on a series of patients with low-grade degenerative scoliosis.

METHODS

Endo-TLIF was applied to patients who had 10°-40° of degenerative adult scoliosis. Pre- and postoperative 1-week, 3-month, and final follow-up clinical status of visual analog scale, Oswestry Disability Index, perioperative complications, and Macnab criteria were collected. Roentgenogram to assess changes in Cobb angles was done.

RESULTS

There was statistically significant improvement of preoperative, 1-week postoperative, 3-month postoperative, and final follow-up mean of visual analog scale scores with 7.72 (5-10), 3.68 (3-6), 2.88 (2-4), and 1.96 (1-3), respectively, and with Oswestry Disability Index mean of 70.4 (52-86), 35.12 (26-56), 27.68 (24-38), and 24 (20-28), respectively (P < 0.05). In terms of Macnab criteria, 100% had good to excellent result. In terms of scoliosis measured by Cobb angle, there was statistically significant improvement.

CONCLUSIONS

Endo-TLIF is a safe and effective procedure in mild to moderate degenerative scoliosis with good early clinical results and improvement in coronal Cobb angle. It can be considered as an option if a short segment(s) fusion is planned for adult degenerative scoliosis.

Comparison of the Safety and Effectiveness of Percutaneous Endoscopic Lumbar Discectomy for Treating Lumbar Disc Herniation Under Epidural Anesthesia and General Anesthesia

OBJECTIVE

To assess the safety and effectiveness of percutaneous endoscopic lumbar discectomy (PELD) under epidural anesthesia (EA) and general anesthesia (GA) for treating lumbar disc herniation (LDH).

METHODS

A retrospective study involving 86 patients with LDH managed by PELD under EA and GA was conducted from July 2018 to March 2019. These patients were divided into 2 groups according to the type of anesthesia. Patient's demographics data as well as the operation time, complications, fluoroscopy shots, visual analog scale (VAS), Oswestry Disability Index (ODI), Japanese Orthopaedic Association (JOA), and MacNab scores of the 2 groups were recorded. All of the patients were followed-up at 6 months after operation.

RESULTS

There were no significant differences were detected in the preoperative demographics between the groups (p > 0.05). Two cases (4.8%) under GA developed transient motor weakness, 3 cases (7.4%) presented numbness of lower limb, and 1 case (2.4%) had cauda equina syndrome after operation. In EA group, 1 case (2.2%) had motor weakness and 3 cases (6.7%) had lower limb numbness, which resolved completely at the last follow-up. There was significant difference between preoperative VAS, JOA, and ODI scores and postoperative scores (p < 0.01). Moreover, there were no differences in the operation time, fluoroscopy shots, and MacNab scores between the 2 groups (p > 0.05).

CONCLUSION

EA and GA in PELD are effective and safe, and no significant difference in complications was observed. Based on our experience, we recommended junior surgeons to perform PELD under EA for getting feedback from the patient to avoid nerve injury and reduce the radiation dose. The concentration of ropivacaine in EA should be considered carefully.

Removal of calcified lumbar disc herniation with endoscopic-matched ultrasonic osteotome - Our preliminary experience

Objective: To evaluate the clinical efficacy, practicability, and safety of an ultrasonic osteotome for percutaneous transforaminal endoscopic discectomy (PTED) in patients with calcified lumbar disc herniation (CLDH).Methods: A total of 25 CLDH patients who underwent PTED at our department between December 2017 and August 2018 were analyzed retrospectively. Post-operative lumbar spine CT was used to evaluate residual calcification. Efficacy was evaluated by pre- and post-operative with the pain visual analog scale (VAS), Oswestry disability index (ODI), and the Modified MacNab Scale; the incidence of intra- and postoperative complications was also analyzed.Results: All procedures were successfully completed and none of the patients was lost to follow-up. Postoperative CT verified the successful removal of calcified protrusions. VAS and ODI scores improved significantly after surgery. Based on the Modified MacNab scale, >90% patients achieved good or excellent outcomes. There were no complications such as dural tear and infection. Seven patients had varying degrees of postoperative dysesthesia. One patient experienced recurrence of herniation within 1 week after operation; successful recovery was achieved after repeat PTED.Conclusions: Use of this ultrasonic osteotome for PTED facilitated effective removal of calcified disc protrusion, relieved nerve compression, and protected the adjacent neurovascular tissues. The instrument may help expand the indications for endoscopic surgery and avoid open surgery for some CLDH patients.

[Minimally invasive decompression techniques for spinal cord stenosis]

BACKGROUND

Lumbar spinal canal stenosis is frequently found among elderly patients and significantly limits their quality of life. Non-surgical therapy is an initial treatment option; however, it does not eliminate the underlying pathology. Surgical decompression of the spinal canal has now become the treatment of choice.

OBJECTIVE

Minimalization of surgical approach strategies with maintaining sufficient decompression of the spinal canal and avoiding disadvantages of macrosurgical techniques, monolateral paravertebral approach with bilateral intraspinal decompression, specific surgical techniques.

MATERIALS AND METHODS

Minimally invasive decompression techniques using a microscope or an endoscope are presented and different surgical strategies depending on both the extent (mono-, bi-, and multisegmental) and the location of the stenosis (intraspinal central, lateral recess, foraminal) are described.

RESULTS

Minimally invasive microscopic or endoscopic decompression procedures enable sufficient widening of the spinal canal. Disadvantages of macrosurgical procedures (e. g., postoperative instability) can be avoided. The complication spectrum overlaps partially with that of macrosurgical interventions, albeit with significantly less marked severity. Subjective patient outcome is clearly improved.

CONCLUSIONS

Referring to modern minimally invasive decompression procedures, surgery of lumbar spinal canal stenosis represents a rational and logical treatment alternative, since causal treatment of the pathology is only possible with surgery.

The Long-term Reoperation Rate Following Surgery for Lumbar Herniated Intervertebral Disc Disease: A Nationwide Sample Cohort Study With a 10-year Follow-up

STUDY DESIGN

A retrospective cohort study of a nationwide sample database.

OBJECTIVE

The objective of the present study was to compare the long-term incidence of reoperation for lumbar herniated intervertebral disc disease (HIVD) after major surgical techniques (open discectomy, OD; laminectomy; percutaneous endoscopic lumbar discectomy, PELD; fusion).

SUMMARY OF BACKGROUND DATA

HIVD is a major spinal affliction; if the disease is intractable, surgery is recommended. Considering both the aging of patients and the chronicity of lumbar degenerative disease, the effect of surgical treatment for the lumbar spine should be durable for as long as possible.

METHODS

The National Health Insurance Service-National Sample Cohort (NHIS-NSC) of Republic of Korea was utilized to establish a cohort of adult patients (N = 1856) who underwent first surgery for lumbar HIVD during 2005 to 2007. Patients were followed for 8 to 10 years. Considering death before reoperation as a competing event, reoperation hazards were compared among surgical techniques using the Fine and Gray regression model after adjustment for age, gender, Charlson comorbidity score, osteoporosis, diabetes, the severity of disability, insurance type, and hospital type.

RESULTS

The overall cumulative incidences of reoperation were 4% at 1 year, 6% at 2 years, 8% at 3 years, 11% at 5 years, and 16% at 10 years. The cumulative incidences of reoperation were 16%, 14%, 16%, and 10% after OD, laminectomy, PELD, and fusion, respectively, at 10 years postoperation, with no difference among the surgical techniques. However, the distribution of reoperation types was significantly different according to the first surgical technique (P < 0.01). OD was selected as the reoperation surgical technique in 80% of patients after OD and in 81% of patients after PELD.

CONCLUSION

The probability of reoperation did not differ among OD, laminectomy, PELD, and fusion during the 10-year follow-up period. However, OD was the most commonly used technique in reoperation.

LEVEL OF EVIDENCE

4.

Small incision discectomy for lumbar disc herniation in 98 patients with 5-year follow-up: A retrospective case series study

Optimal surgical technique to treat lumbar disc herniation (LDH) remains controversial. We described a small incision discectomy technique (SID), and to evaluate its safety and efficacy. A retrospective study involving 98 consecutive patients with LDH managed by SID was conducted. All patients were followed up for 5 years. Outcomes included visual analogue scale (VAS), Japanese Orthopedic Association (JOA), operative time, length of incision, blood loss, hospital stay, hospitalization costs, x-ray exposure, reoperation, and complications. The results were determined to be excellent, good, fair, or poor according to the MacNab classification. All patients completed the 5-year follow-up. Relative to preoperative scores, VAS and JOA were both significantly improved. As a whole, 93.8% (92/98) patients showed excellent or good results, 3.1% (3/98) fair, and 3.1% (92/98) poor. The operation time, length of incision, blood loss, and hospital stay were 50 ± 11.1 minutes, 2.2 ± 0.3 cm, 35 ± 3.5 mL, and 4.3 ± 0.2 days, respectively. Additionally, compared with previous literature reports, the hospitalization costs and x-ray exposure were apparently less. The reoperation and recurrence rate were 3.2% and 2.1%. No complications were observed. From these data we conclude that SID appears to be a safe, cost-effective technique for LDH, and has lower x-rays exposure time when compared with literature of percutaneous endoscopic lumbar discectomy (PELD).

Percutaneous Endoscopic Decompression in Lumbar Canal and Lateral Recess Stenosis - The Surgical Learning Curve

OBJECTIVE

The purpose of this study is to characterize the learning curve of endoscopic lumbar decompression based on peri- and postoperative parameters and to suggest the potential of full endoscopic decompression as a primary treatment option for lumbar canal and lateral recess stenosis.

METHODS

The records of 223 consecutive patients who underwent percutaneous endoscopic decompression by a single surgeon for their lumbar canal and lateral recess stenosis were reviewed. Patients were stratified into group 1 (n=100) and group 2 (n=123), depending on their case number. After the 100th case, the procedural time reached a plateau and subsequent patients were assigned to the second group. Demographics and surgical outcomes, including operative times, change in dural sac dimensions, length of hospital stay, and intraoperative complication rates were compared between the 2 groups. Postoperative clinical outcomes, including the visual analogue scale (VAS), the Oswestry Disability Index (ODI) and reoperation rates were compared between the 2 groups (group 1, n=90; group 2, n=110) by follow-up evaluation.

RESULTS

Procedural times were greater in group 1 than group 2 (group 1, 105.26 minutes; group 2, 67.65 minutes; p<0.05) and they had higher complication rates (group 1, 16% [16 of 100]; group 2, 8.3% [8 of 123]; p<0.05). The length of hospitalization, postoperative improvement in VAS and ODI, and reoperation rates were not different between the groups. In both groups, stenotic spinal canals were effectively decompressed.

CONCLUSION

Continued surgical experience was associated with a reduction in operative times and less intraoperative complications. Although the learning curve was steep and additional surgical experience may be needed to overcome the learning curve, percutaneous full endoscopic lumbar decompression is a safe, clinically-feasible, and effective surgical technique and can be adopted as the primary treatment for lumbar canal and lateral recess stenosis.