The "inside out" transforaminal technique to treat lumbar spinal pain in an awake and aware patient under local anesthesia: results and a review of the literature

Evolution, Current Trends, and Latest Advances of Endoscopic Spine Surgery

Background: The aging of the population in developing and developed countries has led to a significant increase in the health burden of spinal diseases. These elderly patients often have a number of medical comorbidities due to aging. The need for minimally invasive techniques to address spinal disorders in this elderly population group cannot be stressed enough. Minimally invasive spine surgery (MISS) has several proven benefits, such as minimal muscle trauma, minimal bony resection, lesser postoperative pain, decreased infection rate, and shorter hospital stay. Methods: A comprehensive search of the literature was performed using PubMed. Results: Over the past 40 years, constant efforts have been made to develop newer techniques of spine surgery. Endoscopic spine surgery is one such subset of MISS, which has all the benefits of modern MISS. Endoscopic spine surgery was initially limited only to the treatment of lumbar disc herniation. With improvements in optics, endoscopes, endoscopic drills and shavers, and irrigation pumps, there has been a paradigm shift. Endoscopic spine surgery can now be performed with high magnification, thus allowing its application not only to lumbar spinal stenosis but also to spinal fusion surgeries and cervical and thoracic pathology as well. There has been increasing evidence in support of these newer techniques of spine surgery. Conclusions: For this report, we studied the currently available literature and outlined the historical evolution of endoscopic spine surgery, the various endoscopic systems and techniques available, and the current applications of endoscopic techniques as an alternative to traditional spinal surgery.

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.

Identification of the Magna Radicular Artery Entry Foramen and Adamkiewicz System: Patient Selection for Open versus Full-Endoscopic Thoracic Spinal Decompression Surgery

BACKGROUND

Casually cauterizing the radicular magna during routine thoracic discectomy may have dire consequences.

METHODS

We performed a retrospective observational cohort study on patients scheduled for decompression of symptomatic thoracic herniated discs and spinal stenosis who underwent a preoperative computed tomography angiography (CTA) to assess the surgical risks by anatomically defining the foraminal entry level of the magna radicularis artery into the thoracic spinal cord and its relationship to the surgical level.

RESULTS

Fifteen patients aged 58.53 ± 19.57, ranging from 31 to 89 years, with an average follow-up of 30.13 ± 13.42 months, were enrolled in this observational cohort study. The mean preoperative VAS for axial back pain was VAS of 8.53 ± 2.06 and reduced to a postoperative VAS of 1.60 ± 0.92 (p < 0.0001) at the final follow-up. The Adamkiewicz was most frequently found at T10/11 (15.4%), T11/12 (23.1%), and T9/10 (30.8%). There were eight patients where the painful pathology was found far from the AKA foraminal entry-level (type 1), three patients with near location (type 2), and another four patients needing decompression at the foraminal (type 3) entry-level. In five of the fifteen patients, the magna radicularis entered the spinal canal on the ventral surface of the exiting nerve root through the neuroforamen at the surgical level requiring a change of surgical strategy to prevent injury to this important contributor to the spinal cord's blood supply.

CONCLUSIONS

The authors recommend stratifying patients according to the proximity of the magna radicularis artery to the compressive pathology with CTA to assess the surgical risk with targeted thoracic discectomy methods.

The percutaneous spinal endoscopy "isolation zone" technique for discogenic low back pain: a case series study

BACKGROUND

This study aimed to explore the clinical values of the percutaneous spinal endoscopy "isolation zone" technique for discogenic low back pain (DLBP).

METHODS

This retrospective case series study enrolled patients with intervertebral DLBP treated with the percutaneous spinal endoscopy "isolation zone" technique in the department of Orthopedics, Cangzhou central Hospital affiliated to TianJin Medical University between September 2017 and September 2020.

RESULTS

Forty-five patients with DLBP were enrolled. The mean operation time was 94.7 ± 17.7 min. The visual analogue scale (VAS) score of lumbosacral pain was 6.95 ± 1.02 before operation, 2.64 ± 0.71, 1.80 ± 0.54, 1.42 ± 0.50, and 1.27 ± 0.45 at 1, 3, 6, and 12 months after operation, respectively. The Oswestry disability index (ODI) score of low back pain was 72.84 ± 5.95 before operation, 35.1 ± 5.30, 25.22 ± 4.85, 16.78 ± 4.63, and 10.91 ± 2.36 at 1, 3, 6, and 12 months after operation, respectively. At final follow-up, the treatment effect based on modified MacNab criteria was excellent in 24 cases, good in 13 cases, and fair in 8 cases. The excellent/good rate was 82.2%.

CONCLUSION

The percutaneous spinal endoscopic "isolation zone" technique seems to be a promising surgical alternative for DLBP.

A Proposed Personalized Spine Care Protocol (SpineScreen) to Treat Visualized Pain Generators: An Illustrative Study Comparing Clinical Outcomes and Postoperative Reoperations between Targeted Endoscopic Lumbar Decompression Surgery, Minimally Invasive TLIF and Open Laminectomy

Background: Endoscopically visualized spine surgery has become an essential tool that aids in identifying and treating anatomical spine pathologies that are not well demonstrated by traditional advanced imaging, including MRI. These pathologies may be visualized during endoscopic lumbar decompression (ELD) and categorized into primary pain generators (PPG). Identifying these PPGs provides crucial information for a successful outcome with ELD and forms the basis for our proposed personalized spine care protocol (SpineScreen). Methods: a prospective study of 412 patients from 7 endoscopic practices consisting of 207 (50.2%) males and 205 (49.8%) females with an average age of 63.67 years and an average follow-up of 69.27 months was performed to compare the durability of targeted ELD based on validated primary pain generators versus image-based open lumbar laminectomy, and minimally invasive lumbar transforaminal interbody fusion (TLIF) using Kaplan-Meier median survival calculations. The serial time was determined as the interval between index surgery and when patients were censored for additional interventional and surgical treatments for low back-related symptoms. A control group was recruited from patients referred for a surgical consultation but declined interventional and surgical treatment and continued on medical care. Control group patients were censored when they crossed over into any surgical or interventional treatment group. Results: of the 412 study patients, 206 underwent ELD (50.0%), 61 laminectomy (14.8%), and 78 (18.9%) TLIF. There were 67 patients in the control group (16.3% of 412 patients). The most common surgical levels were L4/5 (41.3%), L5/S1 (25.0%), and L4-S1 (16.3%). At two-year f/u, excellent and good Macnab outcomes were reported by 346 of the 412 study patients (84.0%). The VAS leg pain score reduction was 4.250 ± 1.691 (p < 0.001). No other treatment during the available follow-up was required in 60.7% (125/206) of the ELD, 39.9% (31/78) of the TLIF, and 19.7% (12/61 of the laminectomy patients. In control patients, only 15 of the 67 (22.4%) control patients continued with conservative care until final follow-up, all of which had fair and poor functional Macnab outcomes. In patients with Excellent Macnab outcomes, the median durability was 62 months in ELD, 43 in TLIF, and 31 months in laminectomy patients (p < 0.001). The overall survival time in control patients was eight months with a standard error of 0.942, a lower boundary of 6.154, and an upper boundary of 9.846 months. In patients with excellent Macnab outcomes, the median durability was 62 months in ELD, 43 in TLIF, and 31 months in laminectomy patients versus control patients at seven months (p < 0.001). The most common new-onset symptom for censoring was dysesthesia ELD (9.4%; 20/206), axial back pain in TLIF (25.6%;20/78), and recurrent pain in laminectomy (65.6%; 40/61) patients (p < 0.001). Transforaminal epidural steroid injections were tried in 11.7% (24/206) of ELD, 23.1% (18/78) of TLIF, and 36.1% (22/61) of the laminectomy patients. The secondary fusion rate among ELD patients was 8.8% (18/206). Among TLIF patients, the most common additional treatments were revision fusion (19.2%; 15/78) and multilevel rhizotomy (10.3%; 8/78). Common follow-up procedures in laminectomy patients included revision laminectomy (16.4%; 10/61), revision ELD (11.5%; 7/61), and multilevel rhizotomy (11.5%; 7/61). Control patients crossed over into ELD (13.4%), TLIF (13.4%), laminectomy (10.4%) and interventional treatment (40.3%) arms at high rates. Most control patients treated with spinal injections (55.5%) had excellent and good functional outcomes versus 40.7% with fair and poor (3.7%), respectively. The control patients (93.3%) who remained in medical management without surgery or interventional care (14/67) had the worst functional outcomes and were rated as fair and poor. Conclusions: clinical outcomes were more favorable with lumbar surgeries than with non-surgical control groups. Of the control patients, the crossover rate into interventional and surgical care was 40.3% and 37.2%, respectively. There are longer symptom-free intervals after targeted ELD than with TLIF or laminectomy. Additional intervention and surgical treatments are more often needed to manage new-onset postoperative symptoms in TLIF- and laminectomy compared to ELD patients. Few ELD patients will require fusion in the future. Considering the rising cost of surgical spine care, we offer SpineScreen as a simplified and less costly alternative to traditional image-based care models by focusing on primary pain generators rather than image-based criteria derived from the preoperative lumbar MRI scan.

Impact of Body Weight, Height, and Obesity on Selection of Skin Entry Point for Transforaminal Endoscopic Lumbar Discectomy

Background Prospective evaluation of the effect of physical parameters like height, weight and abdominal girth on different skin entry points in transforaminal endoscopic lumbar discectomy (TELD) in lower lumbar discs.

Methods This prospective study involved 174 patients with unilateral radicular pain or discogenic back pain, central, paracentral disc herniations and lateral canal stenosis at the level from L3 to S1 radiologically confirmed by magnetic resonance imaging (MRI) and failed conservative trial for 6 weeks. All patients underwent measurements of height, weight, body mass index (BMI), and abdominal girth preoperatively. All the four possible entry points, i.e., 45 to 45, posterolateral (PL), tip of spinous process (TOSP), and dorsum of the facet joint, were marked and point midway between PL and TOSP (PL-TOSP) skin entry was used.

Results The change in the value, i.e., distance from midline of all the entry points with physical parameters like height, weight, BMI, and abdominal circumference was statistically significant. The visual analog scale score decreased from a preoperative value of 7.98 to 1.84 at 6 months follow-up. The Oswestry disability index score improved from 72.53 to 16.26.

Conclusion The entry point in TELD is not a fixed value as it varies with the physical parameters like weight and abdominal girth of the patient. PL-TOSP is a safe entry point for common pathologies like central, paracentral herniations and lateral canal stenosis in lower lumbar levels and can be predicted preoperatively by proposed formula.

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.

Differential Agnostic Effect Size Analysis of Lumbar Stenosis Surgeries

STUDY DESIGN

A meta-analysis of 89 randomized prospective, prospective, and retrospective studies on spinal endoscopic surgery outcomes.

OBJECTIVE

The study aimed to provide familiar Oswestry Disability Index (ODI), visual analog scale (VAS) back, and VAS leg effect size (ES) data following endoscopic decompression for sciatica-type back and leg pain due to lumbar herniated disc, foraminal, or lateral recess spinal stenosis.

BACKGROUND

Higher-grade objective clinical outcome ES data are more suitable than lower-grade clinical evidence, including cross-sectional retrospective study outcomes or expert opinion to underpin the ongoing debate on whether or not to replace some of the traditional open and with other forms of minimally invasive spinal decompression surgeries such as the endoscopic technique.

METHODS

A systematic search of PubMed, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials from 1 January 2000 to 31 December 2019 identified 89 eligible studies on lumbar endoscopic decompression surgery enrolling 23,290 patient samples using the ODI and VAS for back and leg pain used for the ES calculation.

RESULTS

There was an overall mean overall reduction of ODI of 46.25 (SD 6.10), VAS back decrease of 3.29 (SD 0.65), and VAS leg reduction of 5.77 (SD 0.66), respectively. Reference tables of familiar ODI, VAS back, and VAS leg show no significant impact of study design, follow-up, or patients' age on ES observed with these outcome instruments. There was no correlation of ES with long-term follow-up (P = 0.091). Spinal endoscopy produced an overall ODI ES of 0.92 extrapolated from 81 studies totaling 12,710 patient samples. Provided study comparisons to tubular retractor microdiscectomy and open laminectomy showed an ODI ES of 0.9 (2895 patients pooled from 16 studies) and 0.93 (1188 patients pooled from 5 studies). The corresponding VAS leg ES were 0.92 (12,631 endoscopy patients pooled from 81 studies), 0.92 (2348 microdiscectomy patients pooled from 15 studies), and 0.89 (1188 open laminectomy patients pooled from 5 studies).

CONCLUSION

Successful clinical outcomes can be achieved with various lumbar surgeries. ESs with endoscopic spinal surgery are on par with those found with open laminectomy and microsurgical decompression.

CLINICAL RELEVANCE

This article is a meta-analysis on the benefit overlap between lumbar endoscopy, microsurgical decompression, laminectomy, and lumbar decompression fusion.

LEVEL OF EVIDENCE: 2

History of Endoscopic Spine Surgery in India

Endoscopic spine surgeries provide distinct advantages and is therefore a viable alternative to open or microscopic techniques. Indian surgeons have shown their expertise from craniovertebral junction to lumbosacral spine with these techniques. Many novel approaches like endoscopic transcervical, partial corpectomy, and others have been designed, and many technological innovations for these surgeries have been made. With different training programs attracting both native and international surgeons, the future of endoscopic spine surgery is bright.

Clinical and radiological outcomes of endoscopic foraminoplasty and decompression assisted with preoperative planning software for lumbar foraminal stenosis

PURPOSE

To assess the clinical and radiological outcomes of using endoscopic foraminoplasty and decompression assisted with a preoperative planning software in the treatment of lumbar foraminal stenosis.

METHODS

This retrospective study included 43 patients with lumbar foraminal stenosis (Jan 2018 and June 2019). These patients were divided into two groups. Patients in the conventional group (group A) underwent endoscopic lumbar foraminoplasty and decompression. Patients in the experimental group (group B) underwent the same surgery assisted with a preoperative software. The total operation time, puncture-channel establishment time, and the number of intraoperative fluoroscopic images taken were recorded. The Visual Analog Scale (VAS) and Oswestry Disability Index (ODI) were administered preoperatively and postoperatively (at 1-month, 3-month, and 12-month follow-up). The modified MacNab criteria were used to assess the global outcome at 12-month follow-up.

RESULTS

Patients in group B had shorter operation time, puncture-channel establishment time, and less number of intraoperative fluoroscopic images taken, as compared with group A. The VAS and ODI scores were significantly lower than pre-operation for both groups at all follow-ups. No significant difference was observed between these two groups. Based on the modified MacNab criteria, the excellent-to-good rate was 86.4% in group A and 90.5% in group B, respectively. After the operation, no patients had residual osteophytes in group B, while two patients still had residual osteophytes and foraminal stenosis in group A.

CONCLUSION

For endoscopic surgery treating lumbar foraminal stenosis, using preoperative planning software could reduce the puncture-channel establishment time, operation time, and the number of intraoperative fluoroscopic images taken without affecting the clinical outcomes.

Full-Endoscopic Lumbar Decompression with Minimal Nerve Root Retraction for Impending Neurologic Deficit in Degenerative Lumbar Spine Diseases

OBJECTIVES

 The aim of this retrospective case study was to analyze the outcomes of minimal nerve root retraction in patients with impending neurologic deficit in degenerative lumbar spine disease using the full-endoscopic spine surgery.

MATERIALS AND METHODS

 Thirty-seven consecutive patients with impending neurologic deficit underwent endoscopic spine surgery through either the transforaminal or the interlaminar approach. Their clinical outcomes were evaluated with visual analog scale (VAS) leg pain score, Oswestry Disability Index (ODI), and MacNab's criteria. The outcome of motor deficitis was evaluated with the Medical Research Council (MRC) grade. Completeness of decompression was documented with a postoperative magnetic resonance imaging (MRI) and computed tomography (CT) scan.

RESULTS

 A total of 40 lumbar levels of 37 patients were operated, VAS score of the leg improved from 7.7 ± 1 to 1.9 ± 0.6 (p < 0.0001). ODI score improved from 74.7 ± 6.5 to 25.4 ± 3.49 (p < 0.0001). Motor weakness improved significantly immediately after surgery. The mean MRC grade increased to 1.97, 3.65, 4.41, and 4.76 preoperatively, at 1 week, at 3 months, and at the final follow-up, respectively, and all the patients with foot drop and cauda equina syndrome symptom recovered completely. One patient with great toe drop recovered partially to MRC grade 3. Mean follow-up of the study was 13.3 ± 6.1 months. According to MacNab's criteria, 30 patients (80.1%) had good and 7 patients (18.9%) had excellent results. Three patients required revision surgery.

CONCLUSIONS

 Minimal nerve root retraction during full-endoscopic spine surgery is safe and effective for treatment of the impending neurologic deficit. We could achieve a thorough decompression of the affected nerve root with acceptable clinical outcome and minimal postoperative morbidity.

The Endoscopic Trans-Superior Articular Process Approach: A Novel Minimally Invasive Surgical Corridor to the Lateral Recess

BACKGROUND

Transforaminal approaches to the lumbar spine are typically performed utilizing Kambin's triangle as approach corridor; however, degenerative changes can distort anatomy and expose the exiting nerve root to inadvertent injury.

OBJECTIVE

To describe the surgical technique of a novel full-endoscopic approach to access the lateral recess and report clinical outcomes.

METHODS

The trans-superior articular process (SAP) approach involves partial resection of the SAP, allowing access to the lateral recess both ventral and dorsal to the traversing nerve root. A retrospective review of 40 patients who had undergone a trans-SAP approach for decompression of lateral recess pathology was conducted. Outcomes were measured using visual analog scores (VAS) and Oswestry Disability Index (ODI) at 2 wk, 3 mo, and at last follow-up.

RESULTS

At a mean follow-up of 24 mo, patients experienced statistically significant improvement of the VAS for ipsilateral leg pain, VAS for back pain, and ODI when comparing preoperative values to all postoperative time points. The percentage of patients reaching a minimally clinically important difference for VAS leg pain and ODI was approximately 90% and 88%, respectively. The complication profile was favorable with no dural tears and no postoperative motor or sensory deficits. One patient required revision, with a total reoperation rate of 3%.

CONCLUSION

The trans-SAP approach is a novel approach that utilizes a safe surgical corridor via the SAP to access lateral recess pathology. Our initial clinical experience suggests that the trans-SAP approach allows for treatment of lateral recess and foraminal pathology with low complication rates.

Feasibility of Deep Learning Algorithms for Reporting in Routine Spine Magnetic Resonance Imaging

BACKGROUND

Artificial intelligence is gaining traction in automated medical imaging analysis. Development of more accurate magnetic resonance imaging (MRI) predictors of successful clinical outcomes is necessary to better define indications for surgery, improve clinical outcomes with targeted minimally invasive and endoscopic procedures, and realize cost savings by avoiding more invasive spine care.

OBJECTIVE

To demonstrate the ability for deep learning neural network models to identify features in MRI DICOM datasets that represent varying intensities or severities of common spinal pathologies and injuries and to demonstrate the feasibility of generating automated verbal MRI reports comparable to those produced by reading radiologists.

METHODS

A 3-dimensional (3D) anatomical model of the lumbar spine was fitted to each of the patient's MRIs by a team of technicians. MRI T1, T2, sagittal, axial, and transverse reconstruction image series were used to train segmentation models by the intersection of the 3D model through these image sequences. Class definitions were extracted from the radiologist report for the central canal: (0) no disc bulge/protrusion/canal stenosis, (1) disc bulge without canal stenosis, (2) disc bulge resulting in canal stenosis, and (3) disc herniation/protrusion/extrusion resulting in canal stenosis. Both the left and right neural foramina were assessed with either (0) neural foraminal stenosis absent, or (1) neural foramina stenosis present. Reporting criteria for the pathologies at each disc level and, when available, the grading of severity were extracted, and a natural language processing model was used to generate a verbal and written report. These data were then used to train a set of very deep convolutional neural network models, optimizing for minimal binary cross-entropy for each classification.

RESULTS

The initial prediction validation of the implemented deep learning algorithm was done on 20% of the dataset, which was not used for artificial intelligence training. Of the 17,800 total disc locations for which MRI images and radiology reports were available, 14,720 were used to train the model, and 3560 were used to validate against. The convergence of validation accuracy achieved with the deep learning algorithm for the foraminal stenosis detector was 81% (sensitivity = 72.4.4%, specificity = 83.1%) after 25 complete iterations through the entire training dataset (epoch). The accuracy was 86.2% (sensitivity = 91.1%, specificity = 82.5%) for the central stenosis detector and 85.2% (sensitivity = 81.8%, specificity = 87.4%) for the disc herniation detector.

CONCLUSIONS

Deep learning algorithms may be used for routine reporting in spine MRI. There was a minimal disparity among accuracy, sensitivity, and specificity, indicating that the data were not overfitted to the training set. We concluded that variability in the training data tends to reduce overfitting and overtraining as the deep neural network models learn to focus on the common pathologies. Future studies should demonstrate the accuracy of deep neural network models and the predictive value of favorable clinical outcomes with intervention and surgery.

LEVEL OF EVIDENCE

3.

CLINICAL RELEVANCE

Feasibility, clinical teaching, and evaluation study.

Preoperative Simulation of the Trajectory for L5/S1 Percutaneous Endoscopic Transforaminal Discectomy: A Novel Approach for Decision-Making

OBJECTIVE

We simulated the trajectory for an L5/S1 percutaneous endoscopic transforaminal discectomy (PETD) to guide decision-making for the surgery approach.

METHODS

Twenty-three patients with L5/S1 lumbar disc herniation were included in the study. The patients all underwent thin-section computed tomography scans, after which data were collected for 3-dimensional reconstruction. Simulations of the trajectory for the L5/S1 PETDs were generated and the hindrance of surrounding anatomic structures was evaluated.

RESULTS

Preoperative simulation showed that 14 patients were considered suitable for lumbar PETD. Nine patients were not considered suitable for PETD surgery according to the simulation. Factors affecting the trajectory included high iliac crest in 5 patients, L5 transverse process in 3 patients, and hypertrophic L5-S1 facet joint in 1 patient.

CONCLUSIONS

Preoperative simulation of the trajectory for L5/S1 PETD was helpful in the decision-making for the surgical approach.

Transforaminal Endoscopic Surgery: Outside-In Technique

Transforaminal endoscopic lumbar discectomy (TELD) with the outside-in technique can be applied to nearly all cases of lumbar disc herniation (LDH), and transpedicular endoscopic lumbar discectomy can be used to treat highly migrated LDHs. The purpose of this study was to outline these 2 outside-in surgical techniques and to present their clinical outcomes. Between January 2018 and January 2019, a total of 137 patients underwent either transforaminal or transpedicular endoscopic lumbar discectomy. We performed TELD in 124 patients and transpedicular endoscopic lumbar discectomy in 13 cases. All surgical procedures were performed under conscious sedation. The patients’ mean age was 51.3 years; 51 were women and 86 were men. The overall disc recurrence rate was 5.12%. Visual analogue scale scores decreased significantly in both groups. According to the MacNab criteria, good and excellent results were obtained in 92.74% of patients after transforaminal and in 92.30% of patients after transpedicular endoscopic LDH treatment. The results suggest that TELD with the outside-in technique can be effective for the treatment of most cases of LDH. Transpedicular endoscopic lumbar discectomy can be considered as an alternative treatment for highly migrated LDH.

Lumbar Endoscopic Bony and Soft Tissue Decompression With the Hybridized Inside-Out Approach: A Review And Technical Note

This study aimed to showcase the authors' preferred technique of a hybrid of modern "inside-out" and "outside-in" endoscopic decompression. A case series of 411 patients consisting of 192 females (46.7%) and 219 males (53.3%) with an average age of 54.84 ± 16.32 years and an average of 43.2 ± 26.53 months are presented. Patients underwent surgery for low-grade spondylolisthesis (13 of 411, 3.2%), herniated disc (135 of 411, 32.8%), foraminal spinal stenosis (101 of 411, 24.6%), or a combination of the latter 2 conditions (162 of 411, 39.4%). The preoperative Oswestry Disability Index (ODI) and visual analogue scale (VAS) for leg pain were 49.8 ± 17.65 and 7.9 ± 1.55, respectively. Postoperative ODI and VAS leg were 12.2 ± 9.34 and 2.41 ± 5 1.55 at final follow-up (p < 0.0001). MacNab outcomes were excellent in 134 (32.6%), good in 228 (55.5%), fair in 40 (9.7%), and poor in 9 patients (2.2%), respectively. There was end-stage degenerative vacuum disc disease in 304 of the 411 patients (74%) of which had 37.5% had excellent and 50% good MacNab outcomes. Patients without vacuum discs had excellent and good 18.7% and 71.0% of the time. Direct visualization of pain generators in the epidural- and intradiscal space is the authors' preferred transforaminal decompression technique and is supported by their reliable clinical outcomes.

Uniportal Endoscopic Lumbar Interbody Fusion

The cause of radiculopathy is the compression of the nerve root which can be secondary to sliding of the vertebra and reduced disc height. In some patients, decompression alone does not resolve this problem. We describe the uniportal endoscopic transforaminal lumbar interbody fusion technique. Full-endocopic foraminotomy and discectomy are followed by cage implementation and percutaneous instrumentation. The goal of this surgical method is decompression of nerve roots, segment stabilization, disc height, and sagittal alignment restoration. Uniportal endoscopic facet sparing transforaminal transkambin lumbar interbody fusion is a good surgical option to treat degenerative disc disease, mechanical instability, and spondylolisthesis. This method shows favourable clinical outcomes in selected patients.

Cauda Equina Syndrome: A Review of 15 Patients Who Underwent Percutaneous Transforaminal Endoscopic Lumbar Discectomy (PTELD) Under Local Anaesthesia

INTRODUCTION

To analyse the results of Cauda Equina Syndrome (CES) operated by Percutaneous Transforaminal Endoscopic Lumbar Discectomy (PTELD).

MATERIAL AND METHODS

The study is a retrospective series of 15 patients operated by PTELD. Bladder dysfunction was classified as incomplete CES (CESI) and complete CES retention (CESR). Bladder / motor recovery rate and its timing, Oswestry Disability Index (ODI), Visual Analogue Score (VAS), patient satisfaction index, and sexual dysfunction were used to measure the outcome objectively. Additionally, in CESR patients, post-void residual (PVR) urine was measured by sonography. Complications and technical problems were noted.

RESULTS

There were ten patients of CESI and five patients of CESR. The average follow-up was 20.33(12.05) months. Bladder symptoms recovery was 100%, and motor recovery was 80%. VAS for back pain recovered to 0.53(0.52) from 8(2.39). VAS for leg pain recovered to 0.13(0.35) from 9.20(1.32). ODI improved to 6.07(2.85) from 77.52(13.20). The time to the recovery of bladder function was 1.47(1.55) days. All CESR patient's abnormal PVR urine was normalised at five weeks post-operative. No complications were reported. However, five technical executional problems occurred.

CONCLUSION

PTELD can be considered for CES treatment due to its substantial and quick recovery advantages. However, more evidence support is needed to make it a practice recommendation.

Evolution of endoscopic transforaminal lumbar approach for degenerative lumbar disease

Endoscopic spine surgery has evolved dramatically in last 30 years; with the development of new improved endoscopic optics and instrumentation limitation of endoscopic spine surgery has significantly reduced. The transforaminal approach has been limited in its indications due to its optimized approach and obstacles of bony or neural structures. As the initial transforaminal approach is based on the inside out technique, there were many limitations on the indications. Outside-in approach has been developed to address these limitations. However, the outside-in approach was not free from anatomical obstacles. The mobile outside-in approach technique has advantage of both inside-out and outside-in technique. It is equally safe as inside-out technique and provides an easy handling of structures, while it is equally versatile as outside-in technique in managing different types of disc prolapse such as central, paracentral, foraminal, far lateral, and up and down migration, and in high-canal compromise cases. The mobile outside in technique, however, demands a longer learning curve and beginners need to be patient while learning the technique.

Modified Full-Endoscopic Interlaminar Discectomy via an Inferior Endplate Approach for Lumbar Disc Herniation: Retrospective 3-Year Results from 321 Patients

BACKGROUND

Percutaneous endoscopic interlaminar discectomy (PEID) is a widely used minimally invasive procedure that shows satisfying outcomes for the treatment of L5-S1 and even L4-5 disc herniation. PEID can be divided into direct and indirect approaches according to the established method of the working channel. The direct approach mainly uses the puncture needle directly through the intervertebral space into the intervertebral disc under indirect vision and insertion of the guidewire into the puncture needle to guide the dilator and into the working channel to retract the ligamentum flavum, dural sac, and nerve roots. This approach requires a skilled puncture technique, given the high risk of damage to the nerve roots and dural sac. Therefore, we improved this interlaminar access procedure, placing the puncture target at the inferior endplate and performing preoperative epidurography to expose the spinal nerve roots and dural sac after the puncture needle was passed through the ligamentum flavum. We then positioned the puncture needle at the posterior edge of the superior centrum. Finally, we inserted the working sleeve for the operation. This approach is convenient and effectively reduces the learning curve and intraoperative complications. Here we introduce the procedure and report the safety and efficacy of full-endoscopic interlaminar discectomy via an inferior endplate approach for the treatment of lumbar disc herniation.

METHODS

We performed full-endoscopic interlaminar discectomy via the inferior endplate approach in 321 patients who met our inclusion criteria between May 2014 and May 2017. All operations were completed under local anesthesia. Under fluoroscopic guidance, we performed epidurography to expose the spinal nerve roots and dural sac. The working sleeve and endoscope were then introduced into the inferior endplate of the superior centrum. Herniated disc material was removed using forceps and a laser under clear endoscopic visualization. We retrospectively evaluated the 321 patients with more than 30 months (range, 12-48 months) of follow-up. The therapeutic effects were assessed using scores of the visual analog scale (VAS), Oswestry disability index (ODI), Macnab standard, and infrared thermal imaging.

RESULTS

The mean VAS score for radicular pain improved from 6.3 ± 1.01 preoperatively to 1.01 ± 0.35 at the final follow-up (P < 0.01). The mean ODI score improved from 85.5 ± 12 preoperatively to 12.4 ± 3.7 at the final follow-up (P < 0.01). According to the MacNab standard, the excellent and good outcome scores were 96.5%. The infrared thermal imaging scores indicated significantly improved skin temperature of both lower extremities at 1 week after surgery compared with the preoperation temperature (P < 0.01).

CONCLUSIONS

The inferior endplate approach for percutaneous endoscopic interlaminar discectomy provides a safe and effective alternative for the treatment of lumbar disc herniation.

Minimal Clinically Important Difference in Patient-Reported Outcome Measures with the Transforaminal Endoscopic Decompression for Lateral Recess and Foraminal Stenosis

Background

Patient-reported outcome measures (PROMs) have become widely used to better measure patients' judgment of treatment benefits from surgical spine care. The concept of determining the minimal clinically important differences (MCIDs) of PROMs is aimed at assessing the benefits of lumbar spine care that are meaningful to the patient. The goal of this study was to validate the utility of MCIDs of the visual analog score (VAS) and Oswestry Disability Index (ODI) in patients with sciatica-type low back and leg pain due to lateral recess and foraminal stenosis who were treated with directly visualized transforaminal outpatient endoscopic decompression.

Methods

The retrospective study population consisted of 406 patients on whom PROMs were obtained preoperatively, and again postoperatively at final follow-up. Employing an anchor-based approach with a patient satisfaction index based on the modified Macnab criteria, a receiver operating characteristics (ROC) and area under the curve (AUC) analysis was performed using IBM SPSS 25.0 to define the optimal MCID in VAS and ODI with the transforaminal endoscopy using the top-left-corner criteria and the Youden index. Improvements in walking endurance were recorded as an additional parameter of patient functioning and correlated with PROMs to test for statistical significance.

Results

The patients' average age was 41.08 years, ranging from 30 to 84 years. The mean follow-up was 33.59 months, ranging from 24 to 85 months, with a standard deviation of 12.79. The MCIDs for VAS and ODI were 2.5 to 3.5 and 15 to 16.5, respectively. Patients were dichotomized as improved (377/406; 92.9%) if they reported excellent (224/406; 55.2%), good (112/406; 27.6%), and fair (41/406; 10.1%) Macnab outcomes. Patients were dichotomized as failed if they reported poor (29/406; 7.1%) Macnab outcomes. Preoperatively, only 32.5% (132/406) of patients had unlimited walking endurance compared to 77.6% (315/406) of patients postoperatively. The ROC and AUC analysis showed better accuracy with the single-integer VAS score (0.926) than with the 10-item ODI score (0.751).

Conclusions

Transforaminal outpatient endoscopic decompression for symptomatic foraminal and lateral recess stenosis is an effective surgical treatment to alleviate sciatica-type and back symptoms in 92.9% of patients. Of the PROMs analyzed, the VAS provided a more meaningful and accurate reflection of patients' interpretation of outcome with the transforaminal endoscopic spinal decompression procedure than ODI. Understanding which patient expectations drive these MCIDs may aid in replacing open surgeries for sciatica-type low back and leg pain currently preferred by traditional spine surgeons with a personalized early-staged transforaminal endoscopic hybrid decompressive/ablative procedures favored by the authors. These may prove more cost effective by focusing on significant pain generators validated with a diagnostic interventional workup instead of employing image-based indication criteria for surgery.

Percutaneous Endoscopic Lumbar Discectomy Versus Microdiscectomy for the Treatment of Lumbar Disc Herniation: Pain, Disability, and Complication Rate-A Randomized Clinical Trial

Purpose

The objective was to compare the traditional microdiscectomy with percutaneous endoscopic lumbar discectomy for the treatment of disc herniations regarding pain, disability, and complications.

Methods

Randomized clinical trial with 47 patients with disc herniations treated with 2 different surgical techniques: traditional microdiscectomy or percutaneous endoscopic lumbar discectomy. Forty-seven patients were divided into 2 groups and monitored for 12 months. Irradiated and low back pain were evaluated with the visual analog scale. Surgery complications were recorded.

Results

After surgery, the sciatica and disability improved significantly but without significant differences between the groups. Improvements in back pain were significant until the third month. There were no statistical differences between groups regarding recurrence, infection, and the need for reoperation.

Conclusions

Endoscopic discectomy results are similar to those of conventional microdiscectomy regarding pain and disability improvement. Postoperative lumbar pain is less intense with endoscopic discectomy than conventional microdiscectomy only during the first 3 months. Endoscopic discectomy is a safe and efficient alternative to microdiscectomy.

Clinical Trials

Trial protocol registration number: RBR-5symrd (http://www.ensaiosclinicos.gov.br).

Transforaminal Endoscopic Lumbar Discectomy and Foraminotomy with Modified Radiofrequency Nerve Stimulator and Continuous Electromyography Under General Anesthesia

BACKGROUND

Transforaminal endoscopic lumbar approaches involve working in Kambin's triangle. These procedures are performed on awake patients or under general anesthesia with continuous electromyography. Potential morbidity of this approach includes injury to exiting and traversing nerve roots, as substantial dissection or cauterization of overlying tissues is required for visualization.

METHODS

We developed a novel connection system that accepts input from a bipolar radiofrequency probe to allow direct nerve stimulation in conjunction with electromyography. This study included 30 consecutive patients undergoing transforaminal endoscopic lumbar approaches for discectomies (73.3%), foraminal stenosis (23.3%), or lateral recess stenosis (3.3%). Demographic, operative, and outcomes data were collected.

RESULTS

Average age of patients was 61.4 years, and the L4-5 segment was most commonly treated (65.6%). Electrophysiologic mapping of the exiting nerve root was attempted in 28 patients with an average stimulation threshold of 8.6 ± 0.9 mA. Mapping of the traversing nerve root was attempted in 12 patients with an average stimulation threshold of 6.0 ± 0.8 mA. There were no instances of new postoperative sensorimotor deficits or dysesthesia. These findings persisted through mean and median follow-up of 294 days and 165 days, respectively. No patient required subsequent lumbar surgery.

CONCLUSIONS

Our modified instrumentation and technique allow for accurate identification of the exiting and traversing nerve roots with minimal changes to the workflow of transforaminal endoscopic lumbar approaches. Modification of a bipolar radiofrequency device connection arrangement is simple, inexpensive, and reusable. In this study, no patients developed injury or pain related to nerve root dysfunction.

Suprailiac versus transiliac approach in transforaminal endoscopic discectomy at L5-S1: a new surgical classification of L5-iliac crest relationship and guidelines for approach

Background

Approach to the L5-S1 level with transforaminal access can be challenging. Some surgeons employ the interlaminar or paraspinal endoscopic approach as an alternative apart from the other minimally invasive posterior surgical options. To precisely target and safely access disc herniations at L5-S1, the authors attempted to stratify patients into trans and supra iliac approach groups and propose a simple surgical classification based on the radiographic findings.

Methods

A prospective study was performed on a cohort of 90 patients with L5-S1 disc herniation who underwent transforaminal endoscopic discectomy through suprailiac or transiliac approach depending on the best trajectory to access the herniated disc. Preoperative radiological assessment was done on anteroposterior and lateral radiographs of the lumbosacral spine by two independent observers. The proposed classification and approach guidelines were used to stratify patients for the preferred access route. The outcome was measured as mean VAS and ODI scores pre-operative and at 6 months post-operative and compared using the null hypothesis (P value) and the paired t-test. The interrater reliability was calculated as the percentage agreement between different observers.

Results

The L5-S1 disc herniation was treated with the transforaminal approach in 46 patients via the suprailiac and in the remaining 44 patients via the transiliac approach. There were statistically significant VAS and ODI reductions in patients of both groups (P<0.05). Interrater reliability of 92.5% using percent agreement shows strong level of agreement.

Conclusions

This surgical approach classification based on radiographs aids in the preoperative planning for selection of patients to either suprailiac or transiliac approach for transforaminal endoscopic surgery at L5-S1 level.

Early return to activity after minimally invasive full endoscopic decompression surgery in medical doctors

Full endoscopic surgery including discectomy (FED) and ventral facetectomy (FEVF) is a minimally invasive lumbar decompression surgery that only requires an 8 mm skin incision and can be done under the local anesthesia and sedation. Six male medical doctors underwent the endoscopic decompression (FED/FEVF) for common degenerative lumbar spine problems. Their age ranged from 27 to 63 years of age with a mean of 40 years. Five doctors underwent FED surgery for herniated nucleus pulposus (HNP), and the remaining one physician had FEVF for lumbar lateral recess stenosis. There were no surgery related complications. Postoperatively, 5 out of the 6 physician patients returned the original job within a week because they had clinical duties. The shortest duration to return to work was reported by a 63-year-old orthopedic surgeon resumed working in his clinic 2 days after the FEVF surgery. The longest duration to return to work occurred in general medicine resident who took almost 2 weeks for the sick leave because he did not have clinical duties. The mean duration for the returning to work was 5.8 days after the surgery. At final follow-up ranging from 6 to 30 months, all physician patients were working without any residual pain. In the hands of the authors, the full endoscopic transforaminal decompression surgery is the preferred surgical option and allowed early return to work-an observation that is not the norm in Japan.

Surgical outcome of workman's comp patients undergoing endoscopic foraminal decompression for lumbar herniated disc

Background

Worker's compensation (WC) patients undergoing spine surgery typically experience delayed return to work (RTW) compared with non-WC patients, especially those approved for surgery undergoing traditional open spine surgery. The purpose of this study was to describe the observe RTW rates in WC patients after minimally invasive "selective endoscopic discectomy" (SED™) for a lumbar herniated disc.

Methods

Clinical outcomes using the modified Macnab criteria and RTW data were analyzed in 118 WC patients following the outpatient SED™ procedure in an ambulatory surgery center (ASC) using only local anesthesia with or without sedation. This endoscopic transforaminal decompression was trademarked by Anthony Yeung as SED.

Results

Single-level SED™ was performed in 62 patients, a two-level in 48 patients, a three-level decompression in 6, and a four-level decompression in another two patients, respectively. Patient selection was augmented by diagnostic and therapeutic injections performed preoperatively to determine how many levels of spine segments required surgical intervention. At the two-year follow-up, Excellent Macnab outcome in 36 patients, Good in 53, Fair in another 21, and Poor in the remaining eight patients, respectively. Of the 118 WC patients, 89 (75.42%) were released back to their original job within in 6 weeks from the index operation. The average time to work release was 4.2 months. Twenty-one patients who had previous spine surgery were working. Twenty-nine of the 118 study patients (24.58%) were unable to return to their original job.

Conclusions

In the hands of a well-trained endoscopic spine surgeon, RTW rates with SED™ are higher than with traditional open translaminar surgery. Therefore, endoscopic surgery should be considered for WC patients and further be validated as a cost-effective alternative to open spine surgery.

Patient selection protocols for endoscopic transforaminal, interlaminar, and translaminar decompression of lumbar spinal stenosis

Background

The indications of different endoscopic and endoscopically assisted translaminar approaches for lumbar spinal stenosis are not well-defined, and validated protocols for the use of the transforaminal over the interlaminar approach are lacking.

Methods

We performed a retrospective study employing an image-based patient stratification protocol of stenosis location (type I-central canal, type II-lateral recess, type III-foraminal, type IV-extraforaminal) and clinical outcomes on 249 patients consisting of 137 (55%) men and 112 (45%) women with an average age of 56.03±16.8 years who underwent endoscopic surgery for symptomatic spinal stenosis from January 2013 to February 2019. The average follow-up of 38.27±27.9 months. The primary clinical outcome measures were the Oswestry Disability Index (ODI), Visual Analogue Scale (VAS), and modified Macnab criteria.

Results

The frequency of stenosis configuration in decreasing order was as follows: type I-121/249; 48.6%, type III-104/249; 41.8%, type II-15/249; 6%, and type IV-9/249; 3.6%. The transforaminal approach (137/249; 55.0%) was used in most type II to IV lesions followed by the interlaminar approach (78/249; 31.3%), and the full endoscopic approach (12/249; 4.8%), and the endoscopically assisted translaminar approach (8/249; 3.2%) which was exclusively used for type I lesions. Macnab outcomes analysis showed Excellent in 47 patients (18.9%), Good in 178 (71.5%), Fair in 18 (7.2%) and Poor in 6 (2.4%), respectively. Paired two-tailed t-test showed statistically significant VAS (5.46±2.1; P<0.0001) and ODI (37.1±16.9; P<0.0001) reductions as a result of the endoscopic decompression surgery. Cross-tabulation of the Macnab outcomes versus the endoscopic approach and surgical technique confirmed beneficial association of the approach selection with Excellent (P=0.001) and Good (P<0.0001) outcomes with statistically significance.

Conclusions

This study suggests that in the hands of skilled endoscopic spines surgeon use of an image-based stenosis location protocol may contribute to obtaining Excellent and Good clinical outcomes in a high percentage (93%) of patients suffering from lumbar stenosis related radiculopathy. Additional comparative studies should examine the prognostic value of choosing the endoscopic approach on the basis of the proposed four-type stenosis protocol by correlating its impact on outcomes with preoperative diagnostic injections and intraoperative direct visualization of symptomatic pain generators under local anesthesia and sedation.

Treatment of penetrating trauma to the buttock assisted by spinal endoscopy

Objective

Penetrating trauma to the buttock is relatively common. Because of the location of the trauma and complicated peripheral anatomical structures, surgery to the area can be difficult. We report the cases of 2 patients who sustained penetrating trauma to the buttock and underwent operative treatment assisted by spinal endoscopy.

Methods

With the rapid development of minimally invasive spine surgery techniques in recent years, especially the wide application of endoscopy, we treated 2 cases of penetrating trauma with endoscopic probing within the wound channel, followed by hemostasis and postoperative irrigation and drainage.

Results

Drainage tubes were removed from the 2 patients within 7 days after the surgery. Their wounds were healing well and they were discharged from the hospital within 12 days.

Conclusions

If there is no injury to the large blood vessels, intestines, or urinary system, satisfactory clinical results can be obtained using spinal endoscopy to probe, irrigate, and identify foreign objects, when combined with hemostasis, postoperative short-term irrigation and debridement, and the use of antibiotics.

Use of "Inside-Out" Technique for Direct Visualization of a Vacuum Vertically Unstable Intervertebral Disc During Routine Lumbar Endoscopic Transforaminal Decompression-A Correlative Study of Clinical Outcomes and the Prognostic Value of Lumbar Radiographs

Background

The purpose of this study was to record the frequency of lumbar intervertebral disc vacuum phenomenon on routine lumbar plain films taken prior to transforaminal endoscopic decompression surgery for sciatica-type leg and back pain and to correlate it with visualized intradiscal pathology and clinical outcomes.

Methods

A prospective case series study of 200 consecutive patients with an average mean follow-up of 41.85 months who underwent lumbar endoscopic transforaminal decompression at 236 lumbar levels was conducted. The sensitivity, specificity, and accuracy of vacuum phenomenon on preoperative x-ray to predict the presence of an empty vacuum disc found during transforaminal microdiscectomy using the "inside-out" approach were calculated using the YESS™ technique. Clinical outcomes were assessed by both Macnab criteria and visual analog score (VAS) reduction.

Results

Of the 200 patients evaluated, 124 (62%) were deemed to have a vacuum disc on intraoperative probing using the "inside-out" technique. During needle insertion the more severely degenerative discs are met with negative pressures manifested by an air discogram. According to Macnab criteria, all patients who also had extruded disc herniations had excellent results (8 of 200), with the mean VAS decreasing from 6.1 ± 2.6 preoperatively to 1.9 ± 1.4 at the final follow-up (P < .01). This indicates a more severely degenerative disc causing nonspecific back pain due to lack of anterior column support from the intervertebral disc, accentuating foraminal stenosis. Patients with contained disc herniations (62 of 200) had excellent and good results 82.2% of the time. The mean VAS decreased from 6.9 ± 1.7 preoperatively to 2.2 ± 1.1 at final follow-up (P < .01). This identifies the disc as a contributing factor in low back pain. It can also identify the disc and annulus in combination with foraminal stenosis as a contributing factor. In the spinal stenosis group (130 of 200), 81.5% of patients had excellent to good results, and the mean VAS decreased from 6.3 ± 1.5 preoperatively to 2.1 ± 1.2 at final follow-up (P < .01). An analysis of lumbar x-ray vacuum phenomenon in patients with visualized vacuum disc showed true-positive (35 patients) and false-negative (89 patients), compared with an x-ray negative grading in patients without intraoperatively visualized vacuum disc of false-positive (2 patients); and true-negative (74 patients); this allowed for calculation of sensitivity (28.2%), specificity (97.4%), and positive predictive value (94.6%) of preoperative diagnostic x-ray in relation to intraoperatively visualized presence of the vacuum disc during subsequent endoscopic decompression surgery. Direct endoscopic visualization of the inside of the vacuum disc revealed longitudinal fissuring of the intervertebral disc as the most common finding in 77 of the 124 patients (62.1%) with a vacuum disc. Cavitation with delamination was the second most common observation (21 patients). Fair outcomes were associated with cavitation and delamination of the intervertebral disc from the endplates (P < .0001).

Conclusions

A vacuum phenomenon seen on lumbar x-rays is highly specific for a source of one component that is actually a multiple source of nonspecific common back pain. A vacuum disc being found during "inside-out" transforaminal discectomy actually encompasses the disc, annulus, and foraminal stenosis as a multifactorial source of nonspecific common back pain. Further studies of better prognosticators of failed endoscopic transforaminal discectomy are required and are underway by the coauthors.

Transforaminal full-endoscopic lumbar discectomy under local anesthesia in awake and aware conditions: the inside-out and outside-in techniques

PURPOSE OF THE REVIEW

Transforaminal full-endoscopic lumbar discectomy (TELD) under local anesthesia was first introduced in Japan in 2003. Initially referred to as percutaneous endoscopic discectomy, in 2018, a consensus was reached worldwide and the preferred term is now TELD. The procedure requires only an 8-mm skin incision and causes minimal damage to the paravertebral muscles. Thus, it is the least invasive disc surgery. In this review, we introduce two types of the TELD surgery.

RECENT FINDINGS

Initially, TELD was performed as the "inside-out" technique but was associated with reports of postoperative dysesthesia due to exiting nerve injury. Recently, the "outside-in" technique after foraminoplasty was proposed for safer insertion of the cannula into the disc. Foraminoplasty can widen the narrow foramen, thereby allowing the 8-mm cannula to pass through easily and safely, and thus injury to the exiting nerve root can be theoretically avoided. We described two types of the TELD in this review. Surgeons should be familiar with the inside-out and outside-in techniques for TELD; therefore, we can select appropriate technique for each case.

Extradiscal Epiduroscopic Percutaneous Endoscopic Discectomy for Upper Lumbar Disc Herniation A Technical Note

STUDY DESIGN

This study was a technical case report.

OBJECTIVES

To introduce a new transforaminal percutaneous endoscopic lumbar discectomy (PELD) technique for the treatment of upper lumbar disc herniation using an extradiscal epiduroscopic approach.

SUMMARY OF BACKGROUND DATA

Although upper lumbar disc herniation accounts for only 1%-2% of all cases of lumbar disc herniation, the treatment is difficult and shows relatively poor outcomes compared with lower lumbar disc herniation. The anatomic characteristics of the upper lumbar spine are somewhat different from those of the lower lumbar spine. Thus, conventional transforaminal PELD may fail to remove the herniated disc.

METHODS

In the setting of extradiscal epiduroscopic PELD for upper lumbar disc herniation, the approach angle on the axial plane is ~30 degrees, which is less than that of the conventional transforaminal endoscopic discectomy and the working cannula is directly targeted to the herniated disc. Four patients who presented with back and/or leg pain due to disc herniation at L1-L2 or L2-L3 disc space were treated with extradiscal epiduroscopic PELD.

RESULTS

The patients experienced relief from symptoms and were discharged the next day.

CONCLUSIONS

Extradiscal epiduroscopic PELD is a promising treatment strategy for upper lumbar disc herniation, which may otherwise lead to a poor outcome.

The modified transforaminal endoscopic technique in treating intracanalicular combining foraminal and/or extraforaminal lumbar disc herniations

Background

To develop a modified transforaminal endoscopic spine system (TESSYS^®) technique for treating intracanalicular combining foraminal and/or extraforaminal lumbar disc herniation (ICFE-LDH), and evaluate the technical efficacy and safety.

Methods

Twenty-three patients with ICFE-LDH underwent the modified TESSYS technique were enrolled. Magnetic resonance imaging (MRI) was used to verify the reduction of herniated disc. Pre- and post-operative neurological functions were compared by visual analogue scale (VAS) score, Oswestry disability index (ODI) and the modified MacNab criteria. The technical safety was evaluated by surgical complications.

Results

MRI demonstrated reductions of disc herniations in 22 patients (95.7%) after surgeries. The VAS scores were significantly improved at 1 year follow-up (low back: P=0.001, lower limbs: P<0.001), as well as ODI scores (P<0.001). 22 patients had achieved excellent and good recovery postoperatively according to the modified MacNab criteria. One patient (4.3%) underwent a reoperation due to postoperative recurrence of disc herniation. Another patient complained postoperative causalgia in 8 weeks, the symptom alleviated after conservative treatment at 1 year follow-up (VAS: back, 3, lower limbs, 0; ODI: 20%). The incidence rate of surgical complication was 8.7%.

Conclusions

The modified TESSYS technique is a minimally-invasive, effective and safe surgery for treating ICFE-LDHs in selected patients.

A Mobile Outside-in Technique of Transforaminal Lumbar Endoscopy for Lumbar Disc Herniations

Percutaneous endoscopic transforaminal lumbar discectomy (PETLD) has now become a standard of care for the management of lumbar disc disease. There are two techniques for the introduction of a working cannula with respect to disc-outside-in and inside-out. The aim of this prospective study is to describe the technical aspects of a novel mobile outside-in method in dealing with different types of disc prolapse. A total of 184 consecutive patients with unilateral lower limb radiculopathy due to lumbar disc prolapse were operated on with the mobile outside-in technique of PETLD. Their clinical outcomes were evaluated based on the type of disc prolapse they had, a visual analog scale (VAS) leg pain score, the Oswestry Disability Index (ODI), and the Macnab criteria. The completeness of the decompression was documented with a postoperative magnetic resonance imaging. The mean age of the patients was 50 ± 16 years and the male/female ratio was 2:1. The mean follow-up was 19 ± 6 months. A total of 190 lumbar levels were operated on (L1-L2: n = 4, L2-L3: n = 17, L3-L4: n = 27, L4-5: n = 123, and L5-S1: n = 19). Divided into types, the patient distribution was central: n = 14, paracentral: n = 74, foraminal: n = 28, far lateral: n = 13, superior-migrated: n = 8, inferior migrated: n = 38, and high canal compromise: n = 9. The mean operative time was 35 ± 12 (25 - 56) min and the mean hospital stay was 1.2 ± 0.5 (1-3) days. The VAS score for leg pain improved from 7.5 ± 1 to 1.7 ± 0.9. The ODI improved from 70 ± 8.3 to 23 ± 5. According to the Macnab criteria, 75 patients (40.8%) had excellent results, 104 patients (56.5%) had good results, and 5 patients (2.7%) had fair results. Recurrence (including early and late) was seen in 15 out of the 190 levels that were operated on (7.89%). This article presents a novel outside-in approach that relies on a precise landing within the foramen in a mobile manner and does not solely depend upon the enlargement of the foramen. It is more versatile in application and useful in the management of all types of disc prolapse, even in severe canal compromise and high migration.

A Modified Percutaneous Endoscopic Technique to Remove Extraforaminal Disk Herniation at the L5-S1 Segment

OBJECTIVE

To introduce a modified percutaneous endoscopic lumbar diskectomy (PELD) technique to remove extraforaminal disk herniation at the L5-S1 segment, including the technical essentials and preliminary results.

METHODS

The geometric parameters of the transverse process, facet joint, and sacrum (TFS) space based on imaging examination were measured in 100 common patients. The technical essentials, including working cannula placement and disk removal involved in the technique, were described. Ten cases (7 men and 3 women) with extraforaminal disk herniation at L5-S1 were surgically treated with the PELD technique through the TFS space from June 2015 to March 2017.

RESULTS

The maximum diameter of the TFS space varied from 2.73 to 11.81 mm (6.84 ± 2.01 mm) on the left and 3.00 to 10.47 mm (7.02 ± 2.05 mm) on the right. The distance of possible skin entry points from midline varied from 33.28 to 84.18 mm, and the distance of external iliac vessels to skin varied from 70.05 to 119.14 mm. All 10 patients who underwent the modified PELD technique were back to previous activities in 1 month. Visual analog scale (VAS) or Oswestry Disability Index (ODI) scores reduced to 2.5 ± 2.0 or 25.4 ± 10.8 from 7.5 ± 1.3 or 75.2 ± 13.3, respectively, 1 day after operation. At 30 days after the operation, the VAS score was 1.0 ± 0.6 and ODI score was 10.2 ± 3.2. No neurologic deficit or surgical site infection occurred.

CONCLUSIONS

We introduced a modified PELD technique to remove extraforaminal disk herniation at the L5-S1 segment. This technique was less invasive, effective, and safe. We also summarized a detailed protocol to identify and remove the herniated disk for nerve protection.

Combining YESS and TESSYS techniques during percutaneous transforaminal endoscopic discectomy for multilevel lumbar disc herniation

The authors retrospectively characterized the clinical outcomes of combining the Yeung endoscopic spine system (YESS) and transforaminal endoscopic surgical system (TESSYS) techniques during percutaneous transforaminal endoscopic discectomy (PTED) to treat multilevel lumbar disc herniation.PTED using both YESS and TESSYS was performed on 52 patients with multilevel lumbar disc herniations who had shown no apparent response to previous conservative treatments. Postsurgical follow-ups were conducted at weeks 1, 26, and 48. Patients' preoperative and postoperative performances were assessed by modified MacNab classification, Japanese Orthopedic Association (JOA) scores, Oswestry disability index (ODI), and visual analog scale (VAS), and compared with 34 and 45 patients who were treated only by YESS and TESSYS, respectively.The postsurgery surgeon-performed assessment showed satisfactory results in 98% of the YESS + TESSYS-treated cases. The average operative time was 116 ± 23 minutes, intraoperative bleeding was 19 ± 12 mL, and bed stay was 3 days. No complications occurred, including infection, nerve injury, or spinal canal hematoma. One week after surgery, the modified MacNab classifications of the patients were excellent in 45, good in 6, fair in 1, and poor in 0 (98% were excellent or good). JOA, ODI, and VAS scores for low back pain significantly improved relative to the preoperative assessment (P < .01) and had remained stable at 26 and 48 weeks.PTED that combined YESS and TESSYS techniques, depending on the predominant type of lumbar disc herniation at individual levels, is safe, minimally invasive, and effective.

State-of-the-art transforaminal percutaneous endoscopic lumbar surgery under local anesthesia: Discectomy, foraminoplasty, and ventral facetectomy

Transforaminal (TF) percutaneous endoscopic surgery for the lumbar spine under the local anesthesia was initiated in 2003 in Japan. Since it requires only an 8-mm skin incision and damage of the paravertebral muscles would be minimum, it would be the least invasive spinal surgery at present. At the beginning, the technique was used for discectomy; thus, the procedure was called PELD (percutaneous endoscopic lumbar discectomy). TF approach can be done under the local anesthesia, there are great benefits. During the surgery patients would be in awake and aware condition; thus, severe nerve root damage can be avoided. Furthermore, the procedure is possible for the elderly patients with poor general condition, which does not allow the general anesthesia. Historically, the technique was first applied for the herniated nucleus pulposus. Then, foraminoplasty, which is the enlargement surgery of the narrow foramen, became possible thanks to the development of the high speed drill. It was called the percutaneous endoscopic lumbar foraminoplasty (PELF). More recently, this technique was applied to decompress the lateral recess stenosis, and the technique was named percutaneous endoscopic ventral facetectomy (PEVF). In this review article, we explain in detail the development of the surgical technique of with time with showing our typical cases.

Selection of Tubular and Endoscopic Transforaminal Disc Procedures Based on Disc Size, Location, and Characteristics

The clinical effectiveness of percutaneous and transforaminal endoscopic discectomy procedures has been evaluated by the system used or compared to open laminectomy or micro-discectomy but are not evaluated based on the location and characteristics of the abnormal disc. This review proposes that outcomes are primarily related to disc size, biomechanics, location, and associated segmental fibrotic and bone changes as well as the surgeon's skill in using various systems rather than the specific system used. In these cases, the surgeon needs to decide if the goal of the procedure is simply internal decompression of an abnormal but contained herniated disc or release of the entrapped nerve root by a large contained disc, extruded and migrated disc fragment, or coexistent foraminal stenosis. Percutaneous and tubular transforaminal procedures are quite different, technically ranging from simple discectomy aspirating probes to larger endoscopic systems, providing the capability to remove large extruded free disc fragments, with or without foraminotomy. Recently, the ability to perform interbody fusion has been added to the range of procedures able to be performed endoscopically. At the same time, biologic solutions to disc degeneration are rapidly evolving and may have a place in combination with these procedures. This article reviews the interrelationship between clinical signs and symptoms, radiologic findings, and the biochemistry and biomechanics of the affected disc segment. Understanding the role played by all these factors enables the surgeon to evaluate both the disc and surrounding bone structures pre-operatively to determine if the clinical signs and symptoms are related to enlargement and displacement of a contained disc or compression or impingement of the nerve root. Based on this, the surgeon can choose different surgical systems, allowing simple decompression of a contained disc, possibly adding biologics, with a 'small' system, while a large herniated disc, or extruded fragment, causing root impingement, would require a ‘larger’ system that provides direct endoscopic visualization within the epidural space, foraminal decompression with drills, and direct surgical manipulation and freeing of the nerve root. By choosing the surgical system based on characteristics such as disc size, location, and associated inflammatory and fibrotic changes, the effectiveness of minimally invasive procedures will be more consistent and improve as the surgeon's diagnostic and operative skills improve.

Value of a new pathological classification of lumbar intervertebral disc herniation based on transforaminal endoscopic observations

Removal of herniated disc materials based on an imaging only method may not relieve symptoms in many patients. Therefore, the aim of the present study was to develop a transforaminal endoscopic method of classifying the pathological type of lumber intervertebral disc herniation and to compare the outcomes of surgery based on the pathological type with those of conventional endoscopic disc removal. The records of patients who received endoscopic transforaminal nucleotomy with foraminoplasty for symptomatic lumbar disc herniation between 2009 and 2013 were retrospectively reviewed. Patients were then divided into two groups: Group A, which consisted of 275 patients who received conventional endoscopic transforaminal nucleotomy with foraminoplasty between 2009 and 2011 and group B, which consisted of 316 patients who received ‘targeted’ endoscopic transforaminal nucleotomy with foraminoplasty between 2011 and 2013 (based on the pathological type of disc herniation identified at surgery, including fresh, calcified and scar type based on intraoperative observations). The results showed that there were no significant differences in age, gender, body mass index, symptom duration, operated segments or previous invasive therapies between the two groups. Moreover, evaluation of visual analogue scale pain scores and Oswestry disability index scores revealed that the patients in group B had a greater improvement in symptoms than those in group A (P<0.05). In addition, an age >40 years and a longer symptom duration were associated with the calcified type, and previous invasive therapy was associated with the scar type. Therefore, specific surgical treatment based on the transforaminal endoscopic pathological type can result in better outcomes for patients with lumbar disc herniation.