Use of newly developed instruments and endoscopes: full-endoscopic resection of lumbar disc herniations via the interlaminar and lateral transforaminal approach

New ipsilateral full endoscopic interlaminar approach for L5-S1 foraminal and extraforaminal decompression: technique description and initial case series

BACKGROUND

The L5-S1 interlaminar access described in 2006 by Ruetten et al. represented a paradigm shift and a new perspective on endoscopic spinal approaches. Since then, the spinal community has shown that both the traditional ipsilateral and novel contralateral interlaminar approaches to the L5-S1 foramen are good alternatives to transforaminal access. This study aimed to provide a technical description and brief case series analysis of a new endoscopic foraminal and extraforaminal approach for pathologies at the lumbar L5-S1 level using a new ipsilateral interlaminar approach.

METHODS

Thirty patients with degenerative stenotic conditions at the L5-S1 disc level underwent the modified interlaminar approach. The surgical time, blood loss, occurrence of complications, and clinical outcomes were recorded. The data were compiled in Excel and analyzed using R software version 4.2. All continuous variables are presented as the mean, median, minimum, and maximal ranges. For categorical variables, data are described as counts and percentages.

RESULTS

Thirty patients were included in the study. The cohort showed significant improvements in all quality-of-life scores (ODI, visual analog scale of back pain, and visual analog scale of leg pain). Five cases of postoperative numbness and three cases of postoperative dysesthesia have been reported. No case of durotomy or leg weakness has been reported.

CONCLUSIONS

The fundamental change proposed by this procedure, the new ipsilateral approach, presents potential advantages to surgeons by overcoming anatomical challenges at the L5-S1 level and by providing surgeon-friendly visualization and access. This approach allows for extensive foraminal and extraforaminal decompression, including the removal of hernias and osteophytosis, without causing neural retraction of the L5-S1 roots while maintaining the stability of the operated level.

A novel endoscope-port unit for lumbar microendoscopic surgery: a single-center case series review

Minimally invasive spinal surgery has shown benefits not only from a clinical standpoint but also in some cost-effectiveness metrics. Microendoscopic procedures combine optical advantages of endoscopy with the preservation of bimanual surgical maneuvers that are not feasible with full percutaneous endoscopic procedures. TELIGEN is a new endoscopic platform designed to optimize these operations. Our aim was to present a retrospective review of surgical data from the first consecutive cases applying this device in our institution and describe some of its technical details. 25 patients have underwent procedures using this device at our institution to the date, with a mean follow-up of 341.7 ± 45.1 days. 17 decompression-only procedures, including microendoscopic discectomies (MED) and decompression of stenosis (MEDS), with or without foraminotomies (± MEF) and 8 microendoscopic transforaminal lumbar interbody fusions (ME-TLIF) were performed. Mean age and body mass index (BMI) were respectively 58.8 ± 17.4 years and 27.6 ± 5.3 kg/m2. Estimated blood loss (13 ± 4.8, 12.8 ± 6.98 and 76.3 ± 35.02 mL), postoperative length of hospital stay (11.2 ± 21.74, 22.1 ± 26.85 and 80.7 ± 44.60 h), operative time (130.3 ± 58.53, 121 ± 33.90 and 241.5 ± 45.27 min) and cumulative intraprocedural radiation dose (14.2 ± 6.36, 15.4 ± 12.17 and 72.8 ± 12.26 mGy) are reported in this paper for MED ± MEF, MEDS ± MEF and ME-TLIF, respectively. TELIGEN affords an expanded surgical field of view with unique engineered benefits that provide a promissing platform to enhance minimally invasive spine surgery.

Enhancing contrast distribution with the far lateral approach in lumbar transforaminal epidural steroid injections: A retrospective analysis

BACKGROUND

Herniated intervertebral disc (HIVD) with radiculopathy is a common degenerative spine disorder. Transforaminal epidural steroid injection (TFESI) is one of the pain relief treatments for lumbar radiculopathy recommended by evidence-based guidelines. Adequate contrast distribution is correlated with better pain control, but the best approach has not been confirmed yet.

AIM

To confirm the distribution of contrast medium injected with a new approach of TFESI, that is, far lateral lateral recess approach (FLLR-TFESI).

METHODS

Patients receiving TFESI due to HIVD with radiculopathy between 2010 January and 2020 August were retrospectively enrolled. While the FLLR-TFESI was taken as the experimental group, the conventional approach was viewed as the control group. The baseline characteristics, the pattern of contrast enhancement under fluoroscopic guidance, and the complications of these patients were collected and analyzed.

RESULTS

A total of 380 patients were analyzed (143 in control group and 237 in experimental group). The two groups were balanced in most baseline characteristics, except disc extrusion (p = 0.01) and scoliosis (p = 0.04). The FLLR-TFESI have a better contrast distribution (p < 0.01), even after adjustment (p < 0.001). No intrathecal injection was noted, but higher rate of intra-disc injection was noted in FLLR-TFESI group (10% vs. 3%, p = 0.008).

CONCLUSION

The FLLR-TFESI has a superior contrast enhancement and distribution in comparison to conventional approach. Prospective study to confirm the study result as well as the clinical benefits is suggested in the future.

Bibliometric and Visualization Analysis of Research Hotspots and Frontiers in Endoscopic Lumbar Discectomy

Background

The increasing utilization of endoscopic lumbar discectomy (ELD) in spinal surgery has sparked widespread interest and research. This study utilizes bibliometric analysis to identify current research trends and advancements in this innovative surgical technique, with the goal of informing and improving surgical practices.

Methods

We retrieved relevant literature on ELD from the Science Citation Index Expanded (SCI-Expanded) within the Web of Science Core Collection (WoSCC) database as research samples. Various visualization tools, such as VOSviewer, CiteSpace, Scimago Graphica, Pajek, and online bibliometric platform, were employed to generate scientific knowledge maps for the purpose of visual presentation and data analysis.

Results

Over the past two decades, there has been significant progress in the research related to ELD, particularly since 2016. China has emerged as the most productive country, while South Korea and the United States have exerted greater academic influence. Tongji University has contributed the highest number of research output, while academic achievements published by Wooridul Spine Hospital are highly esteemed by scholars. Lee SH and Ruetten S are the most prolific author and the most highly cited author, respectively. World Neurosurg has published the highest number of publications, while Spine has become the most influential journal. Clinical Neurology and Surgery are the primary subject categories. Research in this field primarily revolves around improving ELD techniques, evaluating postoperative efficacy and prognosis prediction, studying complications and risk factors, as well as comparative research with other surgical techniques. Keywords such as risk factors, LDH, PETD, lumbar spinal stenosis, degeneration, recurrent herniation, laminectomy, local anesthesia, and foraminoplasty highlight the current research hotspots and future cutting-edge trends.

Conclusion

This study employed bibliometric analysis to elucidate the research hotspots and frontiers in ELD. The findings have significant implications for advancing research and development in this field.

Preoperative application of CT and MRI registration in lumbar disc herniation endoscopic surgery could improve the postoperative rehabilitation of patients

BACKGROUND

Percutaneous Endoscopic Lumbar Discectomy (PELD) has emerged as routine treatment for lumbar disc herniation (LDH) due to its minimal invasiveness and quick recovery. However, PELD demands high precision from the surgeon, as the risk of intraoperative complications is substantial, including potential damage to the nerve root and dura, and a higher likelihood of recurrence post-surgery. Thus, preoperative planning utilizing CT and MRI imaging is essential.

METHODS

In this study, the clinical data of 140 patients treated with PELD for LDH from January 2021 to December 2023 were retrospectively analyzed. Patients were categorized into two groups based on whether CT and MRI registration (CMR) was employed for surgical planning: a CMR group (n=68) and a control group (n=72). Data collected included surgery time, hospital stay duration, and scores from the Visual Analog Scale (VAS) for low back and leg pain, as well as the Japanese Orthopaedic Association Lumbar Spine Score (JOA). Differences between the two groups were assessed using the Student's t-test.

RESULTS

No significant difference was found in hospital stay length between the groups (P=0.277). Surgery time was significantly shorter in the CMR group (P<0.001). Prior to surgery, no significant differences in VAS scores for leg and low back pain were observed between the groups (P=0.341 and P=0.131, respectively); however, at 2 months postoperatively, both scores were significantly lower in the CMR group (P<0.001 and P=0.002, respectively). Similarly, no difference in preoperative JOA scores was noted (P=0.750), but at 2 months postoperative, the CMR group exhibited significantly higher scores (P<0.001).

CONCLUSION

Compared with the traditional PELD, the preoperative use of CMR has shown to reduce surgery time, alleviate leg and low back pain, and increase the lumbar JOA score at 2 months after surgery, underscoring its efficacy in enhancing surgical outcomes.

Advances and Challenges in Minimally Invasive Spine Surgery

Minimally invasive spine surgery continues to grow and develop. Over the past 50 years, there has been immense growth within this subspecialty of neurosurgery. A deep understanding of the historical context and future directions of this subspecialty is imperative to developing safe adoption and targeted innovation. This review aims to describe the advancements, and challenges that we face today in minimally invasive spine surgery.

Advances and Challenges of Endoscopic Spine Surgery

The purpose of this paper is to review the data supporting current endoscopic surgical techniques for the spine and the potential challenges and future of the field. The origins of endoscopic spine surgery can be traced back many decades, with many important innovations throughout its development. It can be applied to all levels of the spine, with many robust trials supporting its clinical outcomes. Continued clinical research is needed to explore its expanding indications. Although the limitations of starting an endoscopic program can be justified by its cost effectiveness and positive societal impact, challenges facing its widespread adoption are still present. As more residency and fellowship programs include endoscopy as part of their spine training, it will become more prevalent in hospitals in the United States. Technological advancements in spine surgery will further propel and enhance endoscopic techniques as they become an integral part of a spine surgeon's repertoire.

Feasibility of Endoscopic Lumbar Discectomy in a Remote Government Hospital in Thailand: A Cost-Utility Analysis

BACKGROUND

Treatments for lumbar discectomy have developed over time. Recently, endoscopy has played an important role. However, a major obstacle to endoscopy in rural areas is the cost of surgery, particularly for endoscopes and disposable equipment. We assessed the cost effectiveness of endoscopic lumbar discectomy compared to the traditional open microdiscectomy technique in a government hospital in a developing country.

METHODS

This study focused on 50 patients who underwent endoscopic lumbar discectomy between April 2019 and March 2020 at Yala Regional Hospital and were reviewed by our team. The duration of hospital stays, operative time, follow-up, and clinical outcomes at one, three, and six months postoperatively were observed and compared with 30 patients who underwent microscopic lumbar discectomy. Hospital expenses were calculated and compared using t-tests.

RESULTS

Endoscopic discectomy was 4.00 days length of stay while microscopic discectomy has 9.77 days in averages. The pain score was 8.82 for endoscopic surgery and 9.1 for microscopic surgery. The operative price for the endoscopic discectomy was 144.69 USD higher than that for the open lumbar discectomy because of the disposable equipment. However, each patient in the microdiscectomy group had a longer hospital stay and required more perioperative care, which decreased the difference of the total hospital expenses (1,420.612 vs 1,399.16 USD).

CONCLUSION

Full endoscopic lumbar discectomy is an effective procedure that is beneficial for patients. The total hospital costs are not significantly different between the two procedures. To ensure that more patients receive this benefit and to develop surgical competency in government hospitals, the surgical reimbursement fee for endoscopic discectomy should be more affordable than that for conventional discectomy.

Surgical techniques and perioperative surgical outcomes after discectomy for calcified lumbar disc herniation: a review and meta-analysis

INTRODUCTION

Calcified lumbar disc herniation (CLDH) poses surgical challenges due to longstanding disease and adherence of herniated disc to the surrounding neural structures. The data regarding outcomes after surgery for CLDH are limited. This review was conducted to analyse the surgical techniques, perioperative findings and the postoperative clinical outcomes after surgery for CLDH.

METHODS

PRISMA guidelines were followed whilst conducting this systematic review and meta-analysis. The literature review was conducted on 3 databases (PubMed, EMBASE, and CINAHL). After thorough screening of all search results, 9 studies were shortlisted from which data were extracted and statistical analysis was done. Pooled analysis was done to ascertain the perioperative and postoperative outcomes after surgery for CLDH. Additional comparative analysis was done compared to CLDH with non-calcified lumbar disc herniation (NCLDH) cases.

RESULTS

We included 9 studies published between 2016 and 2022 in our review, 8 of these were retrospective. A total of 356 cases of CLDH were evaluated in these studies with a male preponderance (56.4%). Mean operative time was significantly lower in NCLDH cases compared to CLDH cases. The mean estimated blood loss showed a negative correlation with the percentage of males. Satisfactory clinical outcomes were observed in majority of patients. The risk of bias of the included studies was moderate to high.

CONCLUSION

Surgical difficulties in CLDH cases leads to increase in operative time compared to NCLDH. Good clinical outcomes can be obtained with careful planning; the focus of surgery should be on decompression of the neural structures rather than disc removal.

Pros and Cons of Minimally Invasive Spine Surgery

This paper reviews current knowledge on minimally invasive spine surgery (MISS). Although it has significant advantages, such as less postoperative pain, short hospital stay, quick return to work, better cosmetics, and less infection rate, there are also disadvantages. The long learning curve, the need for special instruments and types of equipment, high costs, lack of tactile sensation and biplanar imaging, some complications that are hard to treat, and more radiation to the surgeon and surgical team are the disadvantages.Most studies remark that the outcomes of MISS are similar to traditional surgery. Although patients demand it more than surgeons, we predict the broad applications of MISS will replace most of our classical surgical approaches.

Full-Endoscopic Technique for Posterior Fossa Decompression in Chiari Malformation

BACKGROUND AND IMPORTANCE

Full-endoscopic techniques are well-described for spinal procedures. Although endoscopic-assisted techniques are reported for posterior fossa decompression (PFD) in Chiari malformation (CM), a full-endoscopic technique is yet to be reported in these patients. The aim of this study was to present and describe a full-endoscopic technique for PFD in patients with CM.

CLINICAL PRESENTATION

Two patients diagnosed with CM were operated on by the full-endoscopic PFD technique. The patients consented to the procedure and to the publication of their image. An endoscope with an oval shaft cross-section with a diameter of 9.3 mm, a working length of 177 mm, a viewing angle of 20°, and a working channel of 5.6 diameters were used. Operative videos were recorded. The surgical steps were easily applied after the clear anatomic landmarks, such as the C1 posterior tubercle and the rectus capitis posterior minor muscles. The patients were followed up for 6 months. Both patients were symptom-free with a significant decrease in Visual Analog Scale score and a good functional outcome assessed by Chicago Chiari Outcome Scale after surgery without any complications.

CONCLUSION

All the steps of the full-endoscopic technique for PFD described by the authors in their previous human cadaveric study were also feasible on patients with CM.

The Endoscopic Lumbar Interbody Fusion: A Narrative Review, and Future Perspective

Lumbar interbody fusion stands as a preferred surgical solution for degenerative lumbar spine diseases. The procedure primarily aims to establish lumbar segment stability, directly addressing patient symptoms associated with spinal complications. Traditional open surgery, though effective, is linked with notable morbidities and extended recovery time. To mitigate these concerns, minimally invasive surgery (MIS) has garnered significant popularity, presenting an appealing alternative with numerous benefits such as reduced soft tissue trauma, decreased blood loss, and expedited recovery. Among MIS procedures, full endoscopic spinal surgery, characterized by its minimal invasiveness, holds the potential to further minimize morbidities while enhancing surgical outcomes. Endoscopic lumbar interbody fusion, a novel procedure within this paradigm, has gained attention for offering advantages comparable to those of minimally invasive transforaminal lumbar interbody fusion. However, the safety, efficacy, and associated surgical techniques and instrument design of this method continue to be subjects of ongoing debate. This paper critically reviews current evidence on the safety, efficacy, and advantages of endoscopic lumbar spinal interbody fusion, examining whether it could indeed supersede existing mainstream techniques.

Interlaminar Endoscopic Lumbar Discectomy Versus Microscopic Lumbar Discectomy: A Preliminary Analysis of L5-S1 Lumbar Disc Herniation Outcomes in Prospective Randomized Controlled Trials

OBJECTIVE

A preliminary report from a single institution, noninferiority, prospective randomized controlled trial is conducted to determine the effectiveness of interlaminar endoscopic lumbar discectomy (IELD) versus microscopic lumbar discectomy (MLD) for the treatment of L5-S1 lumbar disc herniation (LDH).

METHODS

This prospective, noncrossover, randomized controlled trials was conducted at a single neurosurgical center. Patients with symptomatic radiculopathy or intermittent neurogenic claudication caused by LDH were enrolled from July 2016 to July 2021. The study compared the effectiveness of microscopic and full-endoscopic discectomy procedures. Outcome measures included visual analogue scale (VAS) scores for back and leg pain, Oswestry Disability Index scores, radiologic measurements, endurance time of walking, and satisfaction rate.

RESULTS

Of 37 assessed patients, both IELD and MLD groups demonstrated significant improvements in VAS scores for pain over time, with no significant difference between them. For secondary outcomes, the IELD group had a shorter hospital stay and reduced blood loss but a longer operation time than the MLD group. Radiographic evaluations showed no change compared to preoperative data. Patient satisfaction and recovery rates were slightly higher for the MLD group, but both groups were comparable in most evaluations, with complications being minimal.

CONCLUSION

The IELD was noninferior in improving the intensity of back and leg pain and functional disability, compared to the MLD. Additionally, the IELD showed no difference in clinical outcomes for patients in terms of radiographic results and patient satisfaction rates. The results of this research preliminarily demonstrate that the IELD could be considered an effective alternative to MLD for L5-S1 central or paracentral LDH.

Full Endoscopic Spine Surgery with Image-Guided Navigation System as "Hybrid Endoscopic Spine Surgery": A Narrative Review

Endoscopic surgery is adopted as a minimally invasive technique in several surgical fields. Endoscopic spine surgery (ESS) was performed initially for lumbar discectomy but is currently widely utilized for various pathologies. Similar to other endoscopic techniques, ESS has a steep learning curve that has recently been a topic of discussion. Image-guided navigation systems have been developed for spine surgery. Intraoperative computed tomography enables the use of an image-guided navigation system in ESS, which is a suitable approach for managing complex lesions. Full-ESS is currently being adopted for certain cervical pathologies, and the incorporation of an image-guided navigation system will soon enable surgery for other cervical pathologies.

Advantages of Revision Transforaminal Full-Endoscopic Spine Surgery in Patients who have Previously Undergone Posterior Spine Surgery

BACKGROUND

 Revision lumbar spine surgery via a posterior approach is more challenging than primary surgery because of epidural or perineural scar tissue. It demands more extensive removal of the posterior structures to confirm intact bony landmarks and could cause iatrogenic instability; therefore, fusion surgery is often added. However, adjacent segment disease after fusion surgery could be a problem, and further exposure of the posterior muscles could result in multiple operated back syndrome. To address these problems, we now perform transforaminal full-endoscopic spine surgery (TF-FES) as revision surgery in patients who have previously undergone posterior lumbar surgery. There have been several reports on the advantages of TF-FES, which include feasibility of local anesthesia, minimal invasiveness to posterior structures, and less scar tissue with fewer adhesions. In this study, we aim to assess the clinical outcomes of revision TF-FES and its advantages.

METHODS

 We evaluated 48 consecutive patients with a history of posterior lumbar spine surgery who underwent revision TF-FES (at 60 levels) under local anesthesia. Intraoperative blood loss, operating time, and complication rate were evaluated. Postoperative outcomes were assessed using the modified Macnab criteria and visual analog scale (VAS) scores for leg pain, back pain, and leg numbness. We also compared the outcome of revision FES with that of primary FES.

RESULTS

 Mean operating time was 70.5 ± 14.4 (52-106) minutes. Blood loss was unmeasurable. The clinical outcomes were rated as excellent at 16 levels (26.7%), good at 28 (46.7%), fair at 10 (16.7%), and poor at 6 (10.0%). The mean preoperative VAS score was 6.0 ± 2.6 for back pain, 6.8 ± 2.4 for leg pain, and 6.3 ± 2.8 for leg numbness. At the final follow-up, the mean postoperative VAS scores for leg pain, back pain, and leg numbness were 4.3 ± 2.5, 3.8 ± 2.6, and 4.6 ± 3.2, respectively. VAS scores for all three parameters were significantly improved (p < 0.05). There was no significant difference in operating time, intraoperative blood loss, or the complication rate between revision FES and primary FES.

CONCLUSIONS

 Clinical outcomes of revision TF-FES in patients with a history of posterior lumbar spine surgery were acceptable (excellent and good in 73.4% of cases). TF-FES can preserve the posterior structures and avoid scar tissue and adhesions. Therefore, TF-FES could be an effective procedure for patients who have previously undergone posterior lumbar spine surgery.

EFFICACY OF FULL-ENDOSCOPIC INTERLAMINAR AND TRANSFORAMINAL DISCECTOMY FOR LUMBER DISC HERNIATION

A previous study has reported the therapeutic effects of interlaminar/transforaminal approaches under full-endoscopic visualization to treat L5-S1 lumber disc herniation (LDH). However, the comparison of interlaminar/transforaminal approaches to treat other segments of LDH remains unclear.

OBJECTIVE

To evaluate the clinical efficacy of full-endoscopic interlaminar and transforaminal lumbar discectomy to treat LDH.

METHODS

A total of 93 patients with LDH who underwent fully-endoscopic lumbar interlaminar/transforaminal discectomy were retrospectively collected. Patients were divided into a Transforaminal group (n=41) and an Interlaminar group (n=52). Clinical efficacy was evaluated by visual analogue scale (VAS), the Oswestry disability index (ODI), and the modified MacNab scoring system.

RESULTS

Of the 93 patients, involving segments in LDH referred to L3-4, L4-5, and L5-S1. The fluoroscopy times in the Interlaminar group were smaller than that of the Transforaminal group. We found no obvious significances between the Transforaminal and Interlaminar groups regarding operation time, incision length, postoperative landing time, hospitalization, and incision healing time. Postoperative VAS and ODI scores notably improved at follow-up. Besides, almost 90% LDH patients achieved excellent/good outcomes.

CONCLUSION

The full-endoscopic visualization technique via interlaminar and transforaminal approaches safely and effectively treat LDH. Level of Evidence III, Retrospective Study.

Endoscopic versus microscopic discectomy for pathologies of lumbar spine: A nationwide cross-sectional study from a lower-middle-income country

Objective

We conducted a cross-sectional study to assess the preference of spine surgeons between MD for microdiscectomy and endoscopic discectomy (ED) surgery for the management of lumbar pathologies in a lower-middle-income country (LMIC).

Methodology

An online survey assessing the preference of spine surgeons for various lumbar pathologies was developed and disseminated in "Neurosurgery Cocktail" a social media platform. Statistical analyses were performed using SPSS software with a level of significance <0.05.

Results

We received responses from 160 spine surgeons having a median experience of 6.75 years (range 0-42 years) after residency. Most of the spine surgeons preferred MD over ED, preference being homogeneous across all lumbar pathologies. In ED, the interlaminar approach was preferred more frequently than the transforaminal approach. The most commonly chosen contraindication for the interlaminar approach and transforaminal approach was ≥ 3 levels lumbar disc herniation (LDH) (n = 117, 73.1%) and calcified LDH (n = 102, 63.8%), respectively. There was no significant association between the type of approach preferred (MD vs. ED; and interlaminar vs. translaminar endoscopic approach) with the type of workplace and the level of experience.

Conclusion

Spine surgeons were inclined toward MD over ED, due to various reasons, such as a steep learning curve, lack of training opportunities, and upfront expenses. There is a pressing need for the upliftment of ED in LMICs which requires global action.

2nd and 3rd generation full endoscopic lumbar spine surgery: clinical safety and learning curve

AIM

2nd and 3rd generation endoscopic spine surgery techniques offer visualisation of familiar inter-laminar anatomy to spinal surgeons. We have prospectively evaluated the clinical outcome, complications and learning curve associated with these techniques in patients with lumbar spine radiculopathy.

METHODS

This is a prospective study of 50 consecutive patients with radicular pain from disc herniation and/or lateral recess stenosis. In 6 patients, endoscopy couldn't be done. Operating times, PROM's (VAS, ODI and EQ-5D scores) and complication rates of 44 patients were evaluated after mean FU of 52 months (range 39-65). MRI was used to divide these into protrusions (n = 19), extrusions (n = 17) and lateral recess stenosis (n = 8). Evidence about the learning curve was gathered by curvilinear regression analyses.

RESULTS

Using a composite clinical success criterion, 95% patients had a successful outcome, with no major complications. ODI, VAS and EQ-5D scores had a statistically significant improvement and achieved MCID. Revision discectomy rate was only 4.5% (n = 2). MRI based grouping, case sequence and degree of difficulty influenced the duration of surgery and a learning curve was found for protrusions and lateral recess decompressions, but not for extrusions. A learning curve effect was also observed with respect to the ODI.

CONCLUSIONS

Although anatomy visualised in 2nd and 3rd generation endoscopy is familiar to spinal surgeons, our learning curve experience suggests a careful and MRI pathology based take up of this technique in clinical practice, despite its clinical safety in our series.

LEVEL OF EVIDENCE

Level 3, prospective cohort study.

Initial learning curve after switching to uniportal endoscopic discectomy for lumbar disc herniations

PURPOSE

The purpose was to investigate the learning curve for elective endoscopic discectomy performed by a single surgeon who made a complete switch to uniportal endoscopic surgery for lumbar disc herniations in an ambulatory surgery center and determine the minimum case number required to safely overcome the initial learning curve.

METHODS

Electronic medical records (EMR) of the first 90 patients receiving endoscopic discectomy by the senior author in an ambulatory surgery center were reviewed. Cases were divided by approach, transforaminal (46) versus interlaminar (44). Patient-reported outcome measures (visual-analog-score (VAS) and the Oswestry disability index (ODI)) were recorded preoperatively and at 2-week, 6-week, 3-month, and 6-month appointments. Operative times, complications, time to discharge from PACU, postoperative narcotic use, return to work, and reoperations were compiled.

RESULTS

Median operative time decreased approximately 50% for the first 50 patients then plateaued for both approaches (mean: 65 min). No difference in reoperation rate observed during the learning curve. Mean time to reoperation was 10 weeks, with 7(7.8%) reoperations. The interlaminar and transforaminal median operative times were 52 versus 73 min, respectively (p = 0.03). Median time to discharge from PACU was 80 min for interlaminar approaches and 60 min for transforaminal (p < 0.001). Mean VAS and ODI scores 6 weeks and 6 months postoperatively were statistically and clinically improved from preoperatively. The duration of postoperative narcotic use and narcotics need significantly decreased during the learning curve as the senior author realized that narcotics were not needed. No differences were apparent between groups in other metrics.

CONCLUSIONS

Endoscopic discectomy was shown to be safe and effective for symptomatic disc herniations in an ambulatory setting. Median operative time decreases by half over the first 50 patients in our learning curve, while reoperation rates remained similar without the need for hospital transfer or conversion to an open procedure in an ambulatory setting.

LEVEL OF EVIDENCE

Level III, prospective cohort.

Full endoscopic spine surgery

Background

With a dramatic increase in elderly population worldwide, the prevalence of degenerative spine disease is steadily rising. Even though the entire spinal column is affected the problem is more commonly seen in the lumbar, cervical spine and to some extent the thoracic spine. The treatment of symptomatic lumbar disc or stenosis is primarily conservative with analgesics, epidural steroids and physiotherapy. Surgery is advised only if conservative treatment is ineffective. Conventional open microscopic procedures even though are still a gold standard, have the disadvantages of excessive muscle damage and bone resection, epidural scarring along with prolonged hospital stay and increased need of postoperative analgesics. Minimal access spine surgeries minimize surgical access related injury by minimizing soft tissue and muscle damage and also bony resection thus preventing iatrogenic instability and unnecessary fusions. This leads to good functional preservation of the spine and enhances early postoperative recovery and early return to work. Full endoscopic spine surgeries are one of the more sophisticated and advanced form of MIS surgeries.

Purpose

Full endoscopy has definitive benefits over conventional microsurgical techniques. These include better and clear vision of the pathology due to presence of irrigation fluid channel, minimal soft tissue and bone trauma, better and relatively easy approach to deep seated pathologies like thoracic disc herniations and a possibility to avoid fusion surgeries. The purpose of this article is to describe these benefits, give an overview of the two main approaches - transforaminal and interlaminar, their indications, contraindications and their limitations. The article also describes about the challenges in overcoming the learning curve and its future prospectives.

Conclusion

Full endoscopic spine surgery is one of the fastest growing technique in the field of modern spine surgery. Better intraoperative visualization of the pathology, lesser incidence of complications, faster recovery time, less postoperative pain, better relief of symptoms and early return to activity are the main reasons behind this rapid growth. With better patient outcomes and reduced medical costs, the procedure is going to be more accepted, relevant and popular procedure in future.

Tubular Microdiscectomy for Recurrent Lumbar Disc Herniation: A Valuable Alternative to Endoscopic Techniques

OBJECTIVE

The efficacy of tubular microdiscectomy (TMD) in the treatment of recurrent lumbar disc herniation (rLDH) is still unclear, especially compared with the endoscopic technique. We performed a retrospective study to analyze this question.

METHODS

We retrospectively included all patients with an rLDH confirmed by magnetic resonance imaging who underwent TMD between January 2012 and February 2019. The general data included sex, age, body mass index, level of rLDH, first surgical approach, reoperation interval, occurrence of dural leak, re-recurrence, and re-reoperation. The clinical outcome was evaluated using a visual analog scale for leg pain, and the modified MacNab criteria were used to evaluate patient satisfaction.

RESULTS

The visual analog scale score for leg pain was statistically significantly reduced from 7.46 preoperatively to 0.80 postoperatively (P < 0.00001), and the patient satisfaction was good or excellent in 85.7% of cases, according to the modified MacNab criteria. Complications occurred in 3 of the 15 included patients: 2 dural tears (13.3%) and 2 re-recurrence (13.3%), but none of the patients underwent a third surgical procedure.

CONCLUSIONS

TMD seems to be an efficient technique for the surgical treatment of leg pain caused by rLDH. In the literature, this technique seems to be at least as good as the endoscopic technique and is easier to master.

Evaluation of Surgical Indications for Full Endoscopic Discectomy at Lumbosacral Disc Levels Using Three-Dimensional Magnetic Resonance/Computed Tomography Fusion Images Created with Artificial Intelligence

Background and Objectives: Although full endoscopic lumbar discectomy with the transforaminal approach (FED-TF) is a minimally invasive spinal surgery for lumbar disc herniation, the lumbosacral levels present anatomical challenges when performing FED-TF surgery due to the presence of the iliac bone. Materials and Methods: In this study, we simulated whether FED-TF surgery could be safely performed on a total of 52 consecutive cases with L5-S1 or L5-L6 disc herniation using fused three-dimensional (3D) images of the lumbar nerve root on magnetic resonance imaging (MRI) created with artificial intelligence and of the lumbosacral spine and iliac on computed tomography (CT) images. Results: Thirteen of the fifty-two cases were deemed operable according to simulated FED-TF surgery without foraminoplasty using the 3D MRI/CT fusion images. All 13 cases underwent FED-TF surgery without neurological complications, and their clinical symptoms significantly improved. Conclusions: Three-dimensional simulation may allow for the assessment from multiple angles of the endoscope entry and path, as well as the insertion angle. FED-TF surgery simulation using 3D MRI/CT fusion images could be useful in determining the indications for full endoscopic surgery for lumbosacral disc herniation.

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.

Extraforaminal Full-Endoscopic Approach for the Treatment of Lateral Compressive Diseases of the Lumbar Spine

Background: The authors conducted a 2-year retrospective follow-up to investigate the efficiency of an extraforaminal full-endoscopic approach with foraminoplasty used to treat lateral compressive diseases of the lumbar spine in 247 patients. Methods: The visual analogue scale (VAS), Oswestry disability index (ODI), and MacNab scale were used to analyze the results collected during the preoperative and postoperative periods. Results: The most common diagnosis was disk herniation with lateral recess stenosis, and the most common surgical level among patients was between L4 and L5 on the left side. Pain decreased over time, as determined during sessions held to evaluate pain in the lumbar, gluteal, led, and foot regions. The ODI demonstrated significant enhancement over the evaluation period and the MacNab scale classified the surgery as good or excellent. The most common complication was dysesthesia. Conclusions: An extraforaminal full-endoscopic approach with foraminoplasty can be recommended in cases of lateral herniation or stenosis for patients with symptoms of radiculopathy, and for those who have not responded to conventional rehabilitation treatment or chronic pain management. Few complications arose as a result of this approach, and most of them were treated clinically.

Modified Unilateral Biportal Endoscopic Lumbar Discectomy Results in Improved Clinical Outcomes

OBJECTIVE

To evaluate and describe the clinical efficacy and safety of a modified unilateral biportal endoscopic lumbar discectomy.

METHODS

From February 2019 to February 2020, patients who met the inclusion criteria were treated using a modified unilateral biportal endoscopic lumbar discectomy. During the operation, the herniated disc was removed and the ligamentum flavum was preserved. Clinical efficacy was assessed via postoperative imaging and follow-up.

RESULTS

A total of 70 patients were followed up for more than 2 years, including 51 males and 19 females, aged 49.4 ± 16.0 years. All operations were completed and no complications were noted. Postoperative lumbar magnetic resonance imaging showed that the decompression of the nerve root was sufficient and the ligamentum flavum was preserved in all patients. Postoperative lumbar CT showed that the caudal lamina and inferior articular process of the cephalad vertebral were partially removed. Lower back and leg pain were significantly relieved after surgery, and the Oswestry Disability Index was significantly improved compared to presurgery measurements (P ＜ 0.01). After 2 years of follow-up, the sensory and muscle strength of nerve roots were significantly recovered (P ＜ 0.01). According to the MacNab score of the patients, 40 cases were defined as "excellent," 26 cases were "good," 2 cases were "fair," and 2 cases were "poor."

CONCLUSIONS

Modified unilateral biportal endoscopic lumbar discectomy can completely remove a lumbar herniated disc; relieve lower back and leg pain; improve lumbar function; reduce the risk of dural tearing, cerebrospinal fluid leakage, and epidural hematoma; and reduce the epidural adhesion and arachnoiditis caused by ligamentum flavum resection.

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.

Global Trends and Hotspots in Endoscopic Discectomy: A Study Based on Bibliometric Analysis

OBJECTIVE

With the advancement of minimally invasive spine surgery, endoscopic discectomy (ED) has become a common technique for degenerative disease of the spine. The present study aimed to explore the knowledge structure, emerging trends, and future research hotspots in this field.

METHODS

All relevant publications on ED from 2002 to 2021 were extracted from the Web of Science databases. Key bibliometric indicators, including countries/regions, institutions, authors, journals, references, and keywords were calculated and evaluated using VOSviewer and CiteSpace software.

RESULTS

A total of 1,196 articles and reviews were included for analysis. The number of publications regarding ED increased yearly. From the quality and quantity viewpoint, China, South Korea, and the United States were the major contributors in this field. The most influential institution in the field of ED was Wooridul Spine Hospital. We identified 3,488 authors, among which Lee SH had the most significant number of papers, and Ruetten S was cocited most often. <World Neurosurgery was the journal with the most papers, and Spine was the most commonly cocited journal. Keywords were stratified into 4 clusters by VOSviewer software: cluster 1 (clinical outcomes of ED in the treatment of lumbar disc herniation); cluster 2 (surgical technique of percutaneous endoscopic lumbar discectomy); cluster 3 (clinical outcomes of ED in the treatment of lumbar spinal stenosis); and cluster 4 (clinical outcomes of percutaneous endoscopic cervical discectomy). Several topics including lateral recess stenosis, spinal stenosis, and reoperation were considered as the next hotspot in ED research.

CONCLUSION

ED research has gained considerable attention over the last 2 decades. Our bibliometric findings illuminate the publication trends and research hotspots of the ED field, which may provide useful references for scholars and decision-makers interested in this field.

Risk Factors Involved in the Early and Medium-Term Poor Outcomes of Percutaneous Endoscopic Transforaminal Discectomy: A Single-Center Experience

Objective

To investigate the risk factors involved in the early and medium-term poor outcomes of percutaneous endoscopic transforaminal discectomy (PETD) treatment of lumbar disc herniation (LDH) at the L4-5 level.

Methods

Between January 2015 and May 2020, we recruited 148 LDH patients at the L4-5 level who underwent PETD surgery. The patients were divided into Groups A and B, according to the surgical outcomes. Good and excellent outcomes were categorized into Group A, and generally good and poor outcomes were categorized into Group B. Clinical parameters (age, gender, symptom duration, hospital stay, operation time, blood loss, straight-leg raising (SLR), visual analog scale (VAS), Oswestry Disability Index (ODI) score and modified MacNab criteria) and radiologic parameters (foraminal height (FH), intervertebral height index (IHI), intervertebral angle (IVA), sagittal range of motion (sROM), and lumbar lordosis (LL)) were collected and analyzed using univariate and multiple logistic regression analyses.

Results

At the 6-month follow-up post operation, univariate analysis revealed that the symptom duration, SLR, IHI, and sROM were strongly associated with poor outcomes. However, multiple logistic regression analysis demonstrated that prolonged symptom duration, large SLR angel, and large sROM were independent risk factors for poor outcomes. At the 2-year follow-up post operation, univariate analysis suggested that advanced age, prolonged symptom duration, large preoperative VAS score, small FH, small IHI, and large sROM were potential risk factors for poor outcomes. However, multiple logistic regression analysis demonstrated that prolonged symptom duration, small IHI, and large sROM were independent risk factors for poor outcomes.

Conclusion

Our study demonstrated that prolonged symptom duration, large SLR angel, and large sROM were independent risk factors for poor outcomes immediately following PETD at the L4-5 level. However, prolonged symptom duration, small IHI, and large sROM were independent risk factors for poor outcomes at medium-term post PETD at the L4-5 level.

Revision surgery for symptomatic postoperative pseudocyst following full-endoscopic lumbar discectomy: clinical characteristics and surgical strategies

BACKGROUND

A symptomatic postoperative pseudocyst (PP) is a cystic lesion that is formed in the operation area of the intervertebral disc, leading to worse symptoms. Some minority patients who developed PP experienced rapidly aggravating symptoms and could not be treated by any kind of conservative treatment. However, no clinical studies have evaluated the clinical characteristics and surgical strategies of symptomatic PP requiring a revision surgery after full-endoscopic lumbar discectomy (FELD). This study aimed to demonstrate the clinical characteristics and surgical strategies of symptomatic PP requiring a revision surgery after FELD.

METHODS

We retrospectively analyzed the data of patients who received FELD revision surgeries due to symptomatic PP formation between January 2016 and December 2021. Common characteristics, time intervals of symptom recurrence and revision surgery, strategies for conservative treatment and revision surgery, operative time, imaging characteristics, numeric rating scale (NRS) score, Oswestry disability index (ODI) and overall outcome rating based on modified MacNab criteria were analyzed.

RESULTS

Fourteen patients (males = 10, females = 4), with a mean age of 24.4 years, were enrolled. The mean time intervals of symptom recurrence and revision surgery were 43.5 and 18.9 days respectively. While the patients were conservatively managed with analgesics and physical therapy, pain persisted or progressively worsened. In comparison to the initial herniated disc, the PP was larger in 11 cases, and up- or down-migrated in four cases. The PP location included the lateral recess (n = 12), foraminal (n = 1), and centrolateral (n = 1) zones. One of the two cases treated by percutaneous aspiration (PA) was eventually treated by FELD as pain was not relieved. Follow-ups revealed an improved mean NRS score from 7.1 to 1.4, mean ODI from 68.6 to 7.9% and promising overall surgical outcomes.

CONCLUSIONS

The progressively severe pain experienced due to PP might be a result of its enlargement or migration to the lateral recess and foraminal zones. As complete removal of capsule is the goal, we recommend FELD instead of PA.

Full-Endoscopic Lumbar Interbody Fusion Versus Minimally Invasive Transforaminal Lumbar Interbody Fusion with a Tubular Retractor System: A Retrospective Controlled Study

OBJECTIVE

The objective of this study was to compare the safety and clinical efficacy of full-endoscopic lumbar interbody fusion (FE-LIF) and minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF).

METHODS

A total of 70 patients with single-level lumbar degenerative diseases underwent FE-LIF or MIS-TLIF with a tubular retractor system from August 2018 to August 2020. Postoperatively, the efficacy and safety were compared using several clinical and radiological indices.

RESULTS

A total of 32 patients underwent FE-LIF and 38 received MIS-TLIF with a tubular retractor system, and all patients had no apparent complications. The FE-LIF group had higher radiation exposure, longer operation time, and less bleeding than the MIS-TLIF group (P < 0.05). Postoperative lumbar magnetic resonance imaging showed that the nerve decompression was sufficient. The pain in the lower back and legs was significantly relieved, and the Oswestry Disability Index (ODI) score was greatly improved after surgery (P < 0.01) in both the groups. The sensory and motor functions of nerve roots were remarkably recovered in both the groups at the 1-year follow-up (P < 0.05), and there was no significant difference in MacNab scores between the 2 groups. As per Mannion's fusion classification, the interbody fusion rate was significantly better in the FE-LIF group than in the MIS-TLIF group.

CONCLUSIONS

FE-LIF, which is safe, effective, and minimally invasive, exhibits the same clinical efficacy as MIS-TLIF but with longer operation time and increased radiation exposure.

Percutaneous endoscopic interlaminar discectomy via inner border of inferior pedicle approach for downmigrated disc herniation: a retrospective study

Objective

To evaluate the efficacy and feasibility of percutaneous endoscopic interlaminar discectomy (PEID) via the inner border of the inferior pedicle approach for downmigrated disc herniation.

Methods

Seventeen patients who had downmigrated disc herniation were included in this study from May 2020 to February 2021. After PEID via the inner border of the inferior pedicle approach, a retrospective study was conducted on all patients. Radiologic findings were investigated, and based on the level of migration seen on preoperative magnetic resonance imaging (MRI), participants were divided into two types (high-grade and low-grade migrations). Preoperative, 1st post-operative day, 3rd post-operative month, and the final follow-up visual analogue scale (VAS) assessments for back and leg pain and preoperative, 3rd post-operative month, and the final follow-up Oswestry disability index (ODI) evaluations were performed. The clinical effects at the final follow-up were assessed by the modified MacNab criterion.

Results

All patients successfully completed surgery. There were 10 males and 7 females in the group. These patients were 42 years old on average (range, 25–68 years). Four and 13 patients had downmigrated disc herniation with high-grade and low-grade, respectively, on MRI. The mean follow-up duration was 10.47 ± 1.84 months (range, 8–14 months). The mean VAS score for back and leg improved from 5.18 ± 0.81 preoperatively to 1.35 ± 0.49 at the final follow-up (P < 0.05) and 6.94 ± 0.66 preoperatively to 1.47 ± 0.51 at the final follow-up (P < 0.05), respectively. The mean ODI score improved from 48.00 ± 3.64 preoperatively to 18.71 ± 1.31 at the final follow-up (P < 0.05). According to the modified MacNab criterion, 15 patients (88.2%) obtained excellent, while the rest 2 patients (11.8%) reported good outcomes.

Conclusion

PEID via the inner border of the inferior pedicle approach could be a good alternative option for the treatment of downmigrated disc herniation.

Treatment of Calcified Lumbar Disc Herniation by Intervertebral Foramen Remolding: A Retrospective Study

Purpose

This study aimed to investigate the use of the percutaneous intervertebral foramen lens technology for secondary molding of the intervertebral foramen in the treatment of calcified lumbar discs.

Methods

The study included 104 patients who were divided into two groups. Group A comprised 50 patients with calcified lumbar disc herniation and group B comprised 54 patients with non-calcified lumbar disc herniation diagnosed by computed tomography and magnetic resonance imaging. Patients underwent a percutaneous endoscopic lumbar discectomy at our hospital from January 1, 2017, to December 31, 2019. Demographic characteristics before the surgery and perioperative outcomes were retrospectively reviewed. The treatment outcome was analyzed using the numerical rating scale (NRS) score, Oswestry Disability Index (ODI) score, and modified Macnab criteria.

Results

Patients in groups A and B showed significant improvement in both the NRS and ODI scores after the surgery and maintained relatively low ODI and NRS scores during subsequent follow-ups. According to the evaluation under the modified MacNab standard, the good–excellent rate of clinical efficacy was 94% in group A and 92.6% in group B at the 3 month follow-up. In group A, one patient developed neck pain during the surgery, which was diagnosed as spinal hypertension syndrome, and the surgery was suspended until the patient’s condition improved. No similar complications occurred in group B. In both the groups, no patient reported any dural leak, infection, or other related complications.

Conclusion

The use of transforaminal remolding technology can significantly improve the symptoms and dysfunction of patients with calcified and non calcified lumbar disc herniation. There are few intraoperative and postoperative complications and have little impact on vertebral stability. It can provide a reference for the treatment of special types of lumbar disc herniation.

[Analysis of technical advantages and disadvantages of percutaneous endoscopic lumbar interbody fusion and its trend prospect]

OBJECTIVE

To review and evaluate the technical advantages and disadvantages and research progress of percutaneous endoscopic lumbar interbody fusion.

METHODS

The domestic and foreign related research literature on percutaneous endoscopic lumbar interbody fusion was extensively consulted. The advantages, disadvantages, and effectiveness were summarized. And the development trend of this technology was prospected.

RESULTS

Compared with minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF), percutaneous endoscopic lumbar interbody fusion has less intraoperative and postoperative bleeding, better improvement of low back pain in the early stage after operation, and similar long-term effectiveness, fusion rate, and incidence of complication, but a longer learning curve. The operation time of biportal and large-channel uniportal endoscopic lumbar fusion is close to that of MIS-TLIF, but the operation time of small-channel uniportal endoscopic fusion is longer than that of MIS-TLIF.

CONCLUSION

Percutaneous endoscopic lumbar interbody fusion has the advantages of less trauma and good effectiveness, but its learning curve is long, and indications should be strictly selected for this operation. In the future, with the continuous development and complementation of various endoscopic fusion technologies, this technology will gain better application prospects.

The first experience with fully endoscopic posterior cervical foraminotomy and discectomy for radiculopathy performed in Viet Duc University Hospital

The aim of the article is to present the first experience of applying a full-endoscopic posterior cervical foraminotomy and discectomy performed at Viet Duc University Hospital in Hanoi and describe the outcomes of such surgical intervention. This surgical series includes 20 patients underwent surgery through full-endoscopic posterior cervical foraminotomy and discectomy. The definitive diagnosis of the patients and the evidence for surgical treatment was radiculopathy due to lateral or intraforaminal disk herniation, foraminal stenosis, and lateral recess stenosis. Patients with discogenic cervical radiculopathy but with a contraindication to endoscopic posterior cervical foraminotomy and discectomy were not subject to surgical intervention. All patients underwent a CT and MRT examination of the cervical spine before and after surgery as complementary diagnostic methods. Besides radiological diagnostic methods, electroneuromyography and spondylography were performed with functional samples, i.e., with head tilts in the front and back, to eliminate segmental instability. The timing and degree of the root pain syndrome regression were assessed using a VAS scale (visual and analog scale) with a subsequent comparison of preoperative and postoperative performance. Immediately after the operation, all patients noted a complete or nearly complete regression of the pain syndrome.

A Comparison Between Retaining and Resecting the Posterior Longitudinal Ligament in Percutaneous Endoscopic Transforaminal Discectomy for Disc Herniation: A Retrospective Cohort Study

Objective

To compare the efficacy and safety of retaining the posterior longitudinal ligament (PLL) with resecting the PLL in inside‐out percutaneous endoscopic transforaminal discectomy (PETD) surgery for lumbar disc herniation (LDH).

Method

A total of 135 patients with symptomatic LDH who were treated by inside‐out PETD surgery from January 2015 to January 2017were included in this retrospective analysis. There were 38 males and 30 females in the PLL resection group (mean age = 52.40 ± 8.73 years) and 35 males and 32 females in the PLL retention group (mean age = 53.50 ± 9.24 years). The visual analogue scale (VAS) score, Oswestry disability index (ODI), and modified MacNab criteria were used to evaluate clinical outcomes. Operation time, blood loss, recurrence of LDH, and complications were recorded. Three months after surgery, magnetic resonance imaging was performed to confirm that nerve root compression was relieved.

Results

The VAS and ODI scores improved significantly immediately after surgery, at 1 month after surgery, at 3 months after surgery, and at last follow‐up compared with those before surgery (P < 0.01). The scores also improved significantly between immediately after surgery and 1 month after surgery in the two groups (P < 0.001). Multivariate analysis indicated that age ≥ 50 years (odds ratio (OR) = 6.33, 95% confidence interval (CI): 1.64–21.98, P = 0.014), pain duration ≥6 months (OR = 4.68, 95% CI: 1.29–6.51, P = 0.025), pre‐ODI score ≥ 40% (OR = 5.97, 95% CI: 2.41–14.86, P = 0.003) were all associated with poor functional outcomes. There was no significant difference in the excellent/good ratio between the two groups and the mean operation time of the retention group was 71.5% of that of the resection group (82.7 ± 18.5 min vs 115.6 ± 24.6 min, P < 0.01). In the patients, no serious complications, such as dural tear, wound infection, or persistent nerve root injury, were observed during the follow‐up period. There was no significant difference in the complication rate between the two groups (6/68 vs 6/67, P = 0.979). Although the recurrence rate was higher in retention group, there was no significant difference between the two groups (1/68 vs 2/67, P = 0.551).

Conclusion

The PLL is recommended to be retained for inside‐out PETD surgery.

Percutaneous Bilateral Endoscopic Lumbar Interbody Fusion: Technical Note and Preliminary Results

Objective

The purpose of this study was to investigate the feasibility and clinical efficacy of the percutaneous bilateral endoscopy technique (microendoscopic trans-Kambin's triangle lumbar interbody fusion + percutaneous endoscopic transforaminal decompression of the lumbar spinal canal, ME-TKT-LIF+ PETD) in the treatment of lumbar degenerative diseases.

Methods

From May 2016 to September 2018, 29 patients (16 males and 13 females) who suffered from neurologic symptoms due to degenerative lumbar spine disease and underwent percutaneous bilateral endoscopy technique were enrolled. A microendoscope was used for fusion, and a percutaneous endoscope was used for spinal canal decompression. These patients' perioperative and clinical outcome-related parameters were collected and analyzed.

Results

The mean intraoperative blood loss was 72.8 ± 40.6 ml, the operation time was 87.1 ± 10.1 min, the postoperative ambulatory time was 1.69 ± 1.0 days, the hospital stay was 2.6 ± 1.3 days, and the follow-up period was 22.34 ± 4.2 months. The visual analog scale (VAS) and the Oswestry disability index (ODI) were significantly improved at the early postoperative and last follow-up, respectively. According to the modified MacNab criteria, 11 (11/29) cases were rated as excellent, 15 (15/29) as good, and 3 (3/29) as fair, and the excellent and good rate was 89.7%. Twenty-eight (28/29) cases demonstrated solid fusion, and the fusion rate was 96.6%.

Conclusion

The percutaneous bilateral endoscopy technique is safe and feasible in the treatment of lumbar degenerative diseases, with the advantage that more normal anatomical structures are preserved. It is an optional method of lumbar interbody fusion.

Comparison of percutaneous endoscopic and open posterior lumbar interbody fusion for the treatment of single-segmental lumbar degenerative diseases

Background

Endoscopic lumbar interbody fusion has become an emerging technique. Some researchers have reported the technique of percutaneous endoscopic transforaminal lumbar interbody fusion. We propose percutaneous endoscopic posterior lumbar interbody fusion (PE-PLIF) as an alternative approach. The purpose of this study was to assess the clinical efficacy of PE-PLIF by comparing percutaneous endoscopic and open posterior lumbar interbody fusion (PLIF).

Methods

Thirty patients were enrolled in each group. Demographic data, perioperative data, and radiological parameters were collected prospectively. The clinical outcomes were evaluated by visual analog scale (VAS) and Oswestry Disability Index (ODI) scores.

Results

The background data were comparable between the two groups. The mean operation time was longer in the PE-PLIF group. The PE-PLIF group showed benefits in less blood loss and shorter hospital stay. VAS and ODI scores significantly improved in both groups. However, the VAS score of low-back pain was lower in the PE-PLIF group. The satisfaction rate was 96.7% in both groups. The radiological outcomes were similar in both groups. In the PE-PLIF group, the fusion rate was 93.3%, and the cage subsidence rate was 6.7%; in the open PLIF group, the fusion and cage subsidence rates were 96.7% and 16.7%. There were minor complications in one patient in the PE-PLIF group and two in the open PLIF group.

Conclusions

The current study revealed that PE-PLIF is safe and effective compared with open PLIF. In addition, this minimally invasive technique may enhance postoperative recovery by reducing tissue damage and blood loss.

Foundations in Spinal Endoscopy

Spinal endoscopy has revolutionized the way spine surgeons deliver minimally invasive care for appropriately selected patients. The evolution of endoscopy has been tumultuous since its beginnings as a "blind" percutaneous procedure to access the disk until the present state, in which complex decompressions and even fusions can be accomplished through subcentimeter incisions. Engineering has played a crucial role in this evolution with advances in optics, illumination, and instrumentation that have allowed surgeons to work safely and efficiently in smaller and smaller corridors. Finally, the adaptation of enhanced recovery after surgery protocols have complemented the benefits offered by spinal endoscopy to help patients return to the quality of life they seek through surgical intervention. In this article, we explore foundational elements of spinal endoscopy and look ahead to the future of this maturing field.

Remodeling Pattern of Spinal Canal after Full Endoscopic Uniportal Lumbar Endoscopic Unilateral Laminotomy for Bilateral Decompression: One Year Repetitive MRI and Clinical Follow-Up Evaluation

Objective: There is limited literature on repetitive postoperative MRI and clinical evaluation after Uniportal Lumbar Endoscopic Unilateral Laminotomy for Bilateral Decompression. Methods: Clinical visual analog scale, Oswestry Disability Index, McNab’s criteria evaluation and MRI evaluation of the axial cut spinal canal area of the upper end plate, mid disc and lower end plate were performed for patients who underwent single-level Uniportal Lumbar Endoscopic Unilateral Laminotomy for Bilateral Decompression. From the evaluation of the axial cut MRI, four types of patterns of remodeling were identified: type A: continuous expanded spinal canal, type B: restenosis with delayed expansion, type C: progressive expansion and type D: restenosis. Result: A total of 126 patients with single-level Uniportal Lumbar Endoscopic Unilateral Laminotomy for Bilateral Decompression were recruited with a minimum follow-up of 26 months. Thirty-six type A, fifty type B, thirty type C and ten type D patterns of spinal canal remodeling were observed. All four types of patterns of remodeling had statistically significant improvement in VAS at final follow-up compared to the preoperative state with type A (5.59 ± 1.58), B (5.58 ± 1.71), C (5.58 ± 1.71) and D (5.27 ± 1.68), p < 0.05. ODI was significantly improved at final follow-up with type A (49.19 ± 10.51), B (50.00 ± 11.29), C (45.60 ± 10.58) and D (45.60 ± 10.58), p < 0.05. A significant MRI axial cut increment of the spinal canal area was found at the upper endplate at postoperative day one and one year with type A (39.16 ± 22.73; 28.00 ± 42.57) mm2, B (47.42 ± 18.77; 42.38 ± 19.29) mm2, C (51.45 ± 18.16; 49.49 ± 18.41) mm2 and D (49.10 ± 23.05; 38.18 ± 18.94) mm2, respectively, p < 0.05. Similar significant increment was found at the mid-disc at postoperative day one, 6 months and one year with type A (55.16 ± 27.51; 37.23 ± 25.88; 44.86 ± 25.73) mm2, B (72.83 ± 23.87; 49.79 ± 21.93; 62.94 ± 24.43) mm2, C (66.85 ± 34.48; 54.92 ± 30.70; 64.33 ± 31.82) mm2 and D (71.65 ± 16.87; 41.55 ± 12.92; 49.83 ± 13.31) mm2 and the lower endplate at postoperative day one and one year with type A (49.89 ± 34.50; 41.04 ± 28.56) mm2, B (63.63 ± 23.70; 54.72 ± 24.29) mm2, C (58.50 ± 24.27; 55.32 ± 22.49) mm2 and D (81.43 ± 16.81; 58.40 ± 18.05) mm2 at postoperative day one and one year, respectively, p < 0.05. Conclusions: After full endoscopic lumbar decompression, despite achieving sufficient decompression immediately postoperatively, varying severity of asymptomatic restenosis was found in postoperative six months MRI without clinical significance. Further remodeling with a varying degree of increment of the spinal canal area occurs at postoperative one year with overall good clinical outcomes.

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.

Lumbar discectomy with annulus fibrosus closure: a retrospective series of 53 consecutive patients

INTRODUCTION

Lumbar disc herniation is most common degenerative alteration of the spine. Whenever surgical therapy proves to be necessary, recurrent disc herniation is most frequent concern. Here, primary aim was to determine the percentage of patients eligible for insertion of an annular closure device (ACD). Secondary aim to evaluate 12-month incidence of recurrent disc herniation at the operated level. Our hypothesis was that ACD might help in preventing recurrent disc herniation.

METHODS

Patients in a single XXX neurosurgical center underwent limited discectomy alone (n=41, group 1) versus limited discectomy plus ACD (n=12, group 2). Mean postoperative follow-up period was 12 months.

RESULTS

Twelve out of 53 patients (22.6 %) were eligible for ACD implantation. Patients of group 2 were significantly taller (mean 176 cm, p= 0.007) as compared with group 1 (mean 170). The only statistically significant difference of intraoperative parameters between group 1 and 2 was amount of nucleus materiel removed (p= 0.01), being greater in group 2 (mean 0.9) as compared with group 1 (mean 0.3). In group 1 six patients (6/41, 14.6%) presented with symptomatic reherniation at same level of surgery, while in group 2 only one patient experienced recurrence (1/12, 8.3%). No adverse events were reported.

DISCUSSION

In the current study one out of five patients with lumbar disc herniation was considered suitable for ACD placement. In vast majority of these patients reherniation was precluded on the short-term basis. Patients with ACD were taller and had intraoperatively a higher volume of the nucleus pulposus materiel removed.

THE MICROSCOPIC AND ENDOSCOPIC TECHNIQUES IN LUMBAR DISCECTOMY: A SYSTEMATIC REVIEW

ABSTRACT Objectives: To compare microdiscectomy (MD) and endoscopic interlaminar discectomy (EID) as methods for the surgical treatment of lumbar disc herniation, describing their efficiency in reducing hospitalization time, pain, and neurological deficit, and comparing the findings and the quality of studies that used the microscopic and endoscopic techniques. Methods: A systematic literature review that used the PRISMA protocol as a methodology. The search was conducted in the PUBMED/MEDLINE and The Cochrane Library databases, using publications from the last 5 years in Portuguese and English. After applying the inclusion and exclusion criteria and validating the qualified studies via STROBE and CONSORT, there were a total of 16 studies for data compilation. Results: A sample of 1004 patients who underwent lumbar discectomy was obtained, 62% of whom were male, and 493 of whom underwent EID (49%) and 511 MD (51%). The mean patient age was 38.7 years and the predominant vertebral level operated was L5-S1 (64.8%). The EID had shorter surgical time (66.38 min) and hospitalization time (3.3 days), in addition to greater variation in the VAS LLLL score (5.38), while the MD presented greater variation in the VAS LUMBAR score (3.14). Conclusion: EID demonstrated efficacy like that of MD, given the similarity in the results obtained, in addition to non-inferiority in the reduction of pain and neurological deficit, and superiority in surgical and hospitalization times. Level of Evidence I; Systematic review .

PAIN INTENSITY AND FUNCTIONAL STATUS 30 DAYS AFTER SURGERY: DIFFERENCE BETWEEN TRANSFORAMINAL AND INTERLAMINAR PERCUTANEOUS ENDOSCOPICLUMBAR DISCECTOMIES

ABSTRACT Objective: To compare the differences between transforaminal and interlaminar endoscopic approaches in terms of pain intensity and functionality 30 days after the surgical procedure. Methods: A retrospective cohort study, with patients treated by percutaneous interlaminar or transforaminal endoscopic discectomy at the Spine Service of the ISCMPA, in southern Brazil. Data were collected from the patients’ electronic medical records by two independent physicians. The clinical outcomes of pain intensity and lumbar functionality were evaluated, respectively, using the visual analogue scale and the Oswestry Disability Index. Results: Thirty-six patients were included in the study, with a mean age of 50.8 ± 15.3 years, 19 (52.8%) of whom were males. As for the clinical outcomes for both transforaminal and interlaminar percutaneous endoscopic approaches, we observed a statistically significant reduction in pain intensity (mean difference of 3.5 points, p < 0.001) and a statistically significant improvement in functionality (mean difference of 33.2 points, p < 0.001) when we compared the pre- and 30-day postoperative periods, with no significant differences in terms of approaches. The type of technical approach also differed in relation to the patients’ age, the location, type, and migration of the herniated disc, and the patient’s time in the operating room. Conclusion: There was a similar effect on pain reduction and restoration of lumbar functions, 30 days after percutaneous endoscopic discectomy, in both technical approaches, with no significant differences between them. Level of Evidence III; Retrospective comparative study.

Comparison of the Clinical Outcomes of Full-Endoscopic Visualized Foraminoplasty and Discectomy Versus Microdiscectomy for Lumbar Disc Herniation

OBJECTIVE

This retrospective case-control study aimed to evaluate and compare the clinical outcomes of full-endoscopic visualized foraminoplasty and discectomy (FEVFD) with microdiscectomy (MD) for lumbar disc herniation (LDH).

METHODS

Data from 198 patients who presented with LDH between January 2016 and December 2017 treated by either FEVFD or MD were retrospectively analyzed. The inclusion criteria were single-level LDH, unilateral radiating leg pain with or without positive Lasegue's sign, and failure of standard conservative treatment for at least 12 weeks. The patients were categorized into an FEVFD group (n = 102) or an MD group (n = 96), according to the surgical procedure performed. Operative time, time in bed after surgery, postoperative hospitalization time, complications, and reoperations were recorded. Visual analog scales (VAS) for leg and back pain, Oswestry Disability index (ODI), 36-Item Short-Form Health Survey physical function (SF36-PF), and bodily pain (SF36-BP) scores were assessed and compared between the two groups.

RESULTS

The demographic data and baseline characteristics of the two groups were not significantly different. Operative time for the FEVFD group (73.82 ± 20.73 min) was longer than that for the MD group (64.74 ± 17.37 min) (P = 0.003), and fluoroscopy time for the FEVFD group (1.71 ± 0.58s) was longer than that for the MD group (1.30 ± 0.33s) (P < 0.001). However, time in bed experienced in the FEVFD group (8.51 ± 2.10 h) was less than that in the MD group (9.24 ± 2.01 h) (P = 0.014), and postoperative hospitalization time experienced in the FEVFD group (2.89 ± 0.83d) was also shorter than that in the MD group (4.94 ± 1.35d) (P < 0.001). All patients completed 24 months of follow-up. Postoperative scores at each follow-up for the VAS for leg and back pain, ODI, SF36-PF, and SF36-BP all improved significantly for both groups, as compared to the preoperative data (P < 0.05). The mean preoperative and postoperative scores for the VAS for leg and back pain, ODI, SF36-PF, and SF36-BP were not significantly different between the two groups. According to the modified MacNab criteria, the outcomes of the procedures were rated as excellent or good by 92.16% and 93.75% of the patients in the FEVFD and MD groups, respectively. One patient suffered a nerve root injury during the discectomy, one patient suffered from a dural tear, and two patients suffered from a residual herniation in the FEVFD group. One patient in the MD group suffered from poor wound healing. Moreover, recurrence happened in two cases in the FEVFD group, and in one case in the MD group.

CONCLUSION

FEVFD and MD are both reliable techniques for the treatment of symptomatic LDH. FEVFD resulted in a more rapid recovery and equivalent clinical outcomes after 24 months of follow-up.

Endoscopic Spinal Decompression: A Retrospective Review of Pain Outcomes at an Academic Medical Center

INTRODUCTION

 Spinal stenosis is a chronic, debilitating condition that is expected to affect an increasing number of people as the population ages. Symptomatic spinal stenosis, like other spine pathologies, including disc herniation and degenerative disc disease, traditionally required an open decompressive surgical approach if more conservative approaches failed. An emerging alternative has been developed to address the needs of this population of patients in the form of endoscopic spine surgery (ESS). Advantages of ESS include minimal tissue trauma, decreased risk of damage to the neurovascular structures, minimal epidural fibrosis/scarring, reduced hospital stay, early functional recovery, and improved cosmetic outcomes. The purpose of this study was to review the outcomes of patients undergoing transforaminal endoscopic spinal decompression at an academic pain program.

METHODS

We conducted a retrospective review of electronic medical records with approval from the University of Florida Institutional Review Board (IRB #202001529). Twenty patients underwent successful transforaminal endoscopic lumbar spinal decompression surgery at UF Health Pain Medicine from July 1, 2019, to June 1, 2020. The majority of cases were performed at L4-5 (n = 14), followed by an equal number (n = 3) of cases at L3-4 and L5-S1. Preoperative and postoperative visual analog scale (VAS) pain scores from patients' pain clinic appointments were obtained from the electronic health records system to assess the intervention as a pain relief strategy.

RESULTS

 Patients had an average pain reduction of 82% (SD = 31%), resulting in an average postoperative pain score of 1.8 (SD = 2.8) on a 10-point VAS.

CONCLUSION

 This study highlights the benefits of endoscopic spine surgery for patients, including pain reduction and reduced scarring.

Technical Notes of Full Endoscopic Lumbar Interbody Fusion with Anterior Expandable Cylindrical Fusion Cage: Clinical and Radiographic Outcomes at 1-Year Follow-Up

OBJECTIVE

We sought to introduce technical notes of full endoscopic lumbar interbody fusion (FE-LIF) with an anterior expandable cylindrical fusion cage.

METHODS

This study retrospectively reviewed patients who underwent FE-LIF with an anterior expandable cylindrical fusion cage through transforaminal or interlaminar approaches from August 2018 to April 2019. Patient demographics and operation-related complications were recorded. Clinical and radiologic outcomes were evaluated at 1 year after surgery.

RESULTS

A total of 32 patients (34 segments) were included in this study. Among them, 14 received full endoscopic transforaminal lumbar interbody fusion and 18 received full endoscopic interlaminar lumbar interbody fusion. There were significant differences in interbody fusion indications between the 2 groups (P < 0.05). All operations were successfully completed without complications. Postoperative lumbar magnetic resonance imaging showed that nerve decompression was sufficient in all patients, and the visual analog scale scores of low back pain and leg pain, the Oswestry Disability Index scores, and sensory and muscle strength were significantly improved after surgery (P < 0.01). The MacNab score included 9 excellent ratings, 4 good ratings, and 1 fair rating in the full endoscopic transforaminal lumbar interbody fusion group and included 10 excellent ratings and 8 good ratings in the full endoscopic interlaminar lumbar interbody fusion group; the scores were not significantly different between the 2 groups at 1 year after surgery (P > 0.05). Complete interbody fusion was achieved in both groups according to computed tomography at 1 year after surgery.

CONCLUSIONS

FE-LIF is a safe and effective minimally invasive lumbar surgery with an anterior expandable cylindrical fusion cage.

The irony of the transforaminal approach: A comparative cohort study of transforaminal endoscopic lumbar discectomy for foraminal versus paramedian lumbar disc herniation

Transforaminal endoscopic lumbar discectomy (TELD) is useful for soft lumbar disc herniation (LDH). Although the transforaminal approach can reach the foraminal disc zone, the risk of exiting nerve root irritation along the path is considerable. Few studies have assessed the difficulties of TELD for foraminal LDH. The objective of this study is to compare the clinical results of TELD between foraminal or far-lateral LDH and paramedian LDH.Between June 2016 and July 2017, 135 consecutive patients with single-level LDH were treated with TELD for 2 years. Among them, 25 patients had foraminal or far-lateral LDH (foraminal group), and the remaining 110 patients had central or subarticular LDH (paramedian group). Perioperative data and clinical outcomes were evaluated using the visual analog pain scale, Oswestry Disability Index, and modified Macnab criteria.The foraminal group showed a higher rate of significant access pain (24.00% vs 8.19%, P < .05). The foraminal group also had a longer duration of surgery, length of hospital stay, and return to work (all P < .05). Pain scores and functional status were significantly improved in both groups. Although there were no differences in the outcomes at 2 years postoperatively, early pain and disability at 6 weeks were higher in the foraminal group.Ironically, the early clinical results of TELD for foraminal LDH may be less favorable than those for paramedian LDH. Therefore, great care should be taken during TELD for foraminal or far-lateral LDH.

Original Designed Uniportal-Bichannel Spinal Endoscopic System (UBiSES) for Foraminoplasty in Percutaneous Endoscopic Transforaminal Discectomy

OBJECTIVE

The study introduced uniportal-bichannel spinal endoscopic system (UBiSES) and explored the feasibility of applying UBiSES to conduct lumbar foraminoplasty in percutaneous endoscopic transforaminal discectomy (PETD).

METHODS

This is a cohort study. 36 patients confirmed as L5/S1 lumbar disc herniation (LDH) in our hospital from March, 2019 to November, 2019 were enrolled. 36 patients were divided into two groups named the UBiSES group (n = 18, male: female = 8:10) and the TESSYS group (n = 18, male: female = 10:8). The average age of the UBiSES group and the TESSYS group were 40.94 ± 12.39 years old and 39.78 ± 13.02 years old respectively. PETD via uniportal-bichannel foraminoplasty assisted by UBiSES was adopted on the UBiSES group while PETD via conventional foraminoplasty was performed on the TESSYS group. One experienced surgeon with more than 4000 cases of lumbar surgery performed PETD on all patients. The demographic data, the duration of working cannula placement (minutes), decompression time (minutes), radiation exposure time (seconds), complications, Visual Analogue Scale (VAS), Oswestry Disability Index (ODI) scores and modified MacNab criteria were recorded and analyzed. The magnetic resonance imaging (MRI) and computed tomography (CT) were conducted to evaluate the radiographic improvement.

RESULTS

PETD via lumbar foraminoplasty was successfully performed in all cases. The follow-up points were 3 months, 6 months, and 12 months. The average follow-up period of all patients was 15.78 ± 2.29 months. There was no statistic difference in age (P = 0.81), sex (P = 0.51) and follow-up (P = 0.14) between two groups. The duration of working cannula placement was 19.08 ± 2.30 min in the UBiSES group and 24.90 ± 4.71 min in the TESSYS group and there was significant difference between two groups (P < 0.05). There was no statistic difference in decompression time between the UBiSES group (44.18 ± 5.70 min) and the TESSYS group (47.46 ± 5.96 min) (P = 1.70). The radiation exposure time was 28.00 ± 4.70 s in the UBiSES group and 40.50 ± 5.73 s in the TESSYS group respectively, and has significant difference between two groups (P < 0.05). Furthermore, there was significant different in the duration of working cannula placement and radiation exposure time in male or female between the UBiSES group and the TESSYS group (P < 0.05). For male or female, no difference observed in decompression time and follow-up period between two groups. Postoperative VAS of low back and leg at every follow-up point (1 day, 3 months, 6 months, 12 months) was improved significantly in both groups compared with their preoperative VAS (P < 0.05). The postoperative ODI (3 months, 6 months, 12 months) has decreased significantly in both the UBiSES group and the TESSYS group compared with their preoperative ODI (P < 0.05). 94.44% patients received an excellent or good recovery in the UBiSES group and 88.89% for the TESSYS group. There was no poor result reported in both groups. The radiographic images showed satisfactory foraminoplasty and sufficient decompression of nerve in both groups. No postoperative complications were observed during follow-ups in the UBiSES group. Two patients in the TESSYS group experienced postoperative dysesthesia and the symptom was disappeared in 5 days and 7 days respectively with dexamethasone and neurotrophic drugs treatment.

CONCLUSIONS

The original designed UBiSES could effectively and safely enlarge the foramen with an extensive surgical view and space under full-time and real-time visualization and get satisfactory efficacy.

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.