Determining the Maximum Tolerable Concentration of Ropivacaine to Maintain Sensation of the Nerve Root in Percutaneous Endoscopic Transforaminal Lumbar Discectomy: Can Epidural Anaesthesia Achieve Pain-Tactile Separation Block to Avoid Nerve Injury?

Introduction: Nerve injury is a serious complication of percutaneous endoscopic transforaminal lumbar discectomy due to nerve root contact. The maximum tolerable concentration (MTC) of ropivacaine concentration for epidural anaesthesia, is defined as the concentration that minimises pain while preserving the sensation of the nerve roots. This distinct advantage allows the patient to provide feedback to the surgeon when the nerve roots are contacted. Methods: We used a biased-coin design to determine the MTC, which was estimated by the 10% effective concentration (EC10), ie, the concentration at which 10% of patients lost sensation in the nerve roots. The determinant for positive response was lack of sensory feedback upon contact with the nerve root, and the feedback from occurrence of sensations in the innervation area upon contact with the nerve root was defined as a negative response. Primary outcome was the response from contact nerve root. Secondary outcomes were the type and number of statements of negative response and each patient's pain score during surgery. Results: Fifty-four patients were included in this study. The EC10 was 0.434% (95% CI: 0.410%, 0.440%) using isotonic regression in comparison with 0.431% (95% CI: 0.399%, 0.444%) using probit regression. Three type statements of negative response were reported including "tactile sensation", radiculalgia, and numbness. Conclusion: The MTC of ropivacaine used for epidural anaesthesia was 0.434% to avoid nerve injury in percutaneous endoscopic transforaminal lumbar discectomy.

Contrast enhancing epidural fluid accumulation after percutaneous endoscopic lumbar discectomy: A case report of recurrent disc herniation within pseudocyst secondary to irrigation fluid.

INTRODUCTION: Percutaneous endoscopic lumbar discectomy (PELD) is increasingly being utilized to treat patients with lumbar disc herniation. PELD is unique in that it uses a single working port endoscope with constant irrigation of the surgical field to visualize pathology. The current report is of a case of postoperative epidural irrigation fluid accumulation presenting as peripherally enhancing epidural lesions, masking an underlying re-herniation. PRESENTATION OF CASE: A patient with a Lumbar 5-Sacral 1 level disc herniation presenting with radiculopathy was treated using PELD. Following the operation, the patient experienced recurrent pain, prompting a repeat MRI of the lumbar spine. Multiple ring-enhancing lesions within the epidural space were observed, creating diagnostic dilemmas. The differential diagnoses included epidural abscess, pseudomeningocele from unintended durotomy, epidural hematoma, or trapped epidural fluid collection presenting as a pseudocyst with or without recurrent disc herniation. A repeat endoscopic discectomy was performed to confirm the diagnosis of pseudocyst, revealing a recurrent disc herniation. DISCUSSION: Pseudocysts are not an uncommon complication of PELD, typically believed to be due to an inflammatory response to disc fragments. However, in this case, the epidural fluid collection was likely the result of trapped irrigation fluid from continuous irrigation during the procedure, which masked an underlying re-herniation on imaging. CONCLUSION: With the increasing utilization of PELD, it is important to acknowledge unique complications such as fluid accumulation from irrigation within the epidural space. Fluid accumulation can lead to contrast-enhancing pseudocyst formation, which can theoretically lead to mass effect or increased intracranial and intraspinal pressure and may mask additional underlying pathology.

Prognostic factors for residual symptoms following percutaneous endoscopic lumbar discectomy.

To explore the risk factors for residual symptoms following percutaneous endoscopic lumbar discectomy (PELD). A retrospective case-controlled study. From January 2015 to December 2020, consecutive patients who underwent PELD for lumbar disc herniation (LDH) in our department were retrospectively studied. All the patients were followed-up at least two years. Residual symptoms were analyzed for association with baseline data, clinical feature, physical examination, and radiographic characteristics, which were used to detected the risk factors. A total of 339 patients were included in this study, with a mean follow-up of 28.7 ± 3.6 months. Of the enrolled patients, 90 (26.5%) patients experienced residual low back pain (LBP), and 76 (22.4%) patients experienced leg numbness (LN). Multivariate logistic regression analysis revealed that intervertebral disc calcification on CT scans (odd ratio, 0.480; 95% confidence interval: 0.247 ~ 0.932; P < 0.05) was independent risk factor for postoperative residual LBP with odd ratio and longer symptom duration was risk factor for postoperative residual LN (odd ratio, 2.231; 95% confidence interval:1.066 ~ 4.671; P < 0.05). Residual symptoms following transforaminal endoscopic surgery are quite prevalent. Intervertebral disc calcification is a protective factor for residual low back pain, and a longer symptom duration is a risk factor for residual leg numbness.

Investigating the impact of cartilaginous endplate herniation on recovery from percutaneous endoscopic lumbar discectomy.

OBJECTIVE: This study aimed to evaluate the influence of herniation of cartilaginous endplates on postoperative pain and functional recovery in patients undergoing percutaneous endoscopic lumbar discectomy (PELD) for lumbar disc herniation (LDH). METHODS: A retrospective analysis was conducted on 126 patients with LDH treated with PELD at the Third Hospital of Hebei Medical University from January 2021 to January 2022. Whether cartilaginous endplates had herniated was identified by analyzing these specific findings from MRI scans: posterior marginal nodes, posterior osteophytes, mid endplate irregularities, heterogeneous low signal intensity of extruded material, and Modic changes in posterior corners and mid endplates. Patients were assessed for postoperative pain using the Visual Analogue Scale (VAS) and functional recovery using the Oswestry Disability Index (ODI) and Modified MacNab criteria. Statistical analyses compared outcomes based on the presence of herniation of cartilaginous endplates. RESULTS: Patients with herniation of cartilaginous endplates experienced higher pain scores early postoperatively but showed significant improvement in pain and functional status over the long term. The back pain VAS scores showed significant differences between the groups with and without herniation of cartilaginous endplates on postoperative day 1 and 1 month (P < 0.05). Leg pain VAS scores showed significant differences on postoperative day 1 (P < 0.05). Modic changes were significantly associated with variations in postoperative recovery, highlighting their importance in predicting patient outcomes. In patients with herniation of cartilaginous endplates, there were statistically significant differences in the back pain VAS scores at 1 month postoperatively and the ODI functional scores on postoperative day 1 between the groups with and without Modic changes (P < 0.05). There were no significant differences in the surgical outcomes between patients with and without these conditions regarding the Modified MacNab criteria (P > 0.05). CONCLUSION: Herniation of cartilaginous endplates significantly affect early postoperative pain and functional recovery in LDH patients undergoing PELD. These findings emphasize the need for clinical consideration of these imaging features in the preoperative planning and postoperative management to enhance patient outcomes and satisfaction.

Percutaneous endoscopic lumbar discectomy combined with platelet-rich plasma injection for lumbar disc herniation: analysis of clinical and imaging outcomes.

OBJECTIVE: To evaluate the clinical efficacy and imaging outcomes of percutaneous endoscopic lumbar discectomy (PELD) combined with platelet-rich plasma (PRP) for the treatment of lumbar disc herniation (LDH). METHODS: A total of 155 patients with LDH between January 2020 and June 2022 were retrospective analyzed, of which 75 underwent PELD with PRP and 80 underwent PELD only. Clinical functional scores and imaging data were compared. Clinical functional scores included visual analog scale of leg pain (VAS-LP) and back pain (VAS-BP), Japanese Orthopedic Association score (JOA), Oswestry Disability Index (ODI) and modified MacNab criteria. Imaging data included disc height index (DHI), spinal cross-sectional area (SCSA), disc protrusion size (DPZ), and ratio value of disc grey scales (RVG). RESULTS: Both groups showed clinical improvement, and VAS-LP, VAS-BP, JOA and ODI were significantly improved in the PRP group compared with the control group at 3, 6 and 12 months postoperatively (P < 0.05). At the last follow-up, the differences in SCSA, DPZ and RVG between the two groups were statistically significant (P < 0.05), with the PRP group being superior to the control group. The excellent and good rates of the modified Macnab criteria in the PRP group and control group were 93.3% and 90%, respectively, with no statistically significant difference (P > 0.05). No serious complications occurred during the follow-up period. CONCLUSION: PELD combined with PRP is a safe and effective method for treating patients with LDH. PRP injection was beneficial for delaying disc degeneration and promoting disc remodeling.

Modified Percutaneous Endoscopic Interlaminar Discectomy through the Near-spinous Process Approach for L4/5 Disc Herniation: A Retrospective Clinical Study.

OBJECTIVE: Compared with traditional open surgery, percutaneous endoscopic lumbar discectomy (PELD) has the advantages of less trauma, faster recovery, and less postoperative pain, so it has been widely used in the field of spinal surgery. However, it still has the defect of intraoperative fluoroscopy occurrences, complications, and even the risk of damage to the spinal cord and nerve. This study aims to compare the clinical efficacy of modified percutaneous endoscopic interlaminar discectomy (MPEID) with percutaneous endoscopic transforaminal discectomy (PETD) in treating L4/5 lumbar disc herniation (LDH) and to evaluate the effectiveness and safety of MPEID. METHODS: Thirty-four L4/5 LDH patients treated at the Second Affiliated Hospital of Nanchang University from June 2020 to June 2021 were studied retrospectively. Seventeen underwent MPEID and seventeen PETD. Variables analyzed included demographics, operative duration, intraoperative fluoroscopy occurrences, and surgical outcomes. Effectiveness was evaluated using the visual analogue scale (VAS), Oswestry disability index (ODI), and modified MacNab criteria. Lumbar Magnetic Resonance Imaging (MRI) was used to assess radiological outcomes. A paired t-test was performed to compare intragroup pre- and postoperative clinical data, VAS, and ODI scores. RESULTS: The average operative time in PETD group was 91.65 ± 14.04 min, and the average operative time in MPEID group was 65.41 ± 12.61 min (p < 0.001). In PETD group, the fluoroscopy occurrences averaged 9.71 ± 1.05 times, with fluoroscopy occurrences averaging 6.47 ± 1.00 times (p < 0.001) in MPEID group. At 12 months follow-up, the clinical effect showed significant improvement in both two groups. The MPEID group showed a decrease in average VAS-back score from 5.41 ± 2.18 to 1.76 ± 1.09 (p < 0.001) and VAS-leg score from 6.53 ± 1.66 to 0.82 ± 0.64 (p < 0.001). The ODI scores decreased from 51.35 ± 10.65 to 11.71 ± 2.91 (p < 0.001). In the PETD group, the VAS-back score decreased from 4.94 ± 1.98 to 2.06 ± 1.25 (p < 0.001), VAS-leg score from 7.12 ± 1.73 to 1.12 ± 0.60 (p < 0.001), and ODI scores from 48.00 ± 11.62 to 12.24 ± 2.56 (p < 0.001). According to the modified MacNab criteria, MPEID had 15 excellent and two good results; PETD had 12 excellent and 5 good (p = 0.23). No nerve root injuries, dural tears, or significant complications were reported. CONCLUSION: MPEID and PETD effectively treat L4/5 LDH, with MPEID showing shorter operative times and fewer fluoroscopies. Furthermore, the MPEID group can provide excellent clinical efficacy as the PETD group in the short term.

Associations of recurrent lumbar disc herniation after percutaneous endoscopic lumbar discectomy with age, body mass index, modic change, disc degeneration and sacral slope: A quantitative review.

Recurrent lumbar disc herniation (rLDH) seriously affects the quality of life of patients and increases the medical burden. The purpose of the present study was to determine the risk factors for rLDH after percutaneous endoscopic lumbar discectomy (PELD). The PubMed, Cochrane Library and Embase databases were searched for studies on the factors associated with rLDH after PELD. The databases were searched from inception to March 30, 2023. The combined effects of categorical variables and continuous variables were measured using odds ratios (ORs) and weighted mean differences (WMDs), respectively, and their corresponding 95% confidence intervals (CIs) were calculated. RevMan 5.3 software was used for data analysis. A total of 9 case-control studies were included in this meta-analysis, comprising 5,446 patients. This study explored a total of 18 potential risk factors for rLDH after PELD; ultimately, 5 factors were associated with the risk of rLDH. Meta-analysis showed that older age (WMD=6.49, 95% CI: 2.52 to 10.46), greater body mass index (WMD=1.16, 95% CI: 0.69 to 1.62), modic change (OR=2.48, 95% CI: 1.54 to 3.99), Pfirrmann grade ≥4 (OR=2.84, 95% CI: 1.3 to 6.16) and greater sacral slope angle (WMD=3.48, 95% CI: 0.53 to 6.42) were risk factors for rLDH after PELD. The risk factors identified in the present study may enable clinicians to identify high-risk populations early and to select appropriate surgical procedures to reduce the risk of rLDH. Perioperative interventions targeting the modifiable factors identified in this study may be beneficial for reducing the risk of rLDH.

Correlation between Disc Imaging Observations and Clinical Efficacy after Percutaneous Endoscopic Lumbar Discectomy: A 1-Year Follow-up Study.

OBJECTIVE: The connection between alterations in the disc structure following percutaneous endoscopic lumbar discectomy (PELD) and symptoms in patients postsurgery has not been reported yet. The purpose of the present study was to discuss the potential correlation between the changes in the morphological characteristics of various reference surfaces of the intervertebral disc after percutaneous endoscopic lumbar discectomy (PELD) and clinical outcomes, to identify the morphological parameters that affect efficacy and provide an evidence-based foundation for assessing postoperative efficacy. METHODS: From October 2019 to October 2021, after percutaneous endoscopic lumbar discectomy (PELD), 98 individuals were enrolled. MRI DICOM data of the lumbar spine were obtained before and after surgery, specifically around 3 months. The morphological parameters of the operated and adjacent segments of the discs were measured using T2-weighted images from three reference planes. Outcomes were assessed using the Oswestry disability index (ODI), visual analogue pain scores for the back and leg (VAS-back/VAS-leg), Japanese Orthopaedic Association (JOA) scores, and recovery rates. Postoperative changes in disc parameters and outcomes were compared between patients with different severity and types of LDH based on the MSU staging. Patients completed the questionnaire during outpatient follow-up appointments 3, 6, and 12 months after the surgery. The follow-up period was 14.69 ± 4.21 months, ranging from 12 to 24 months. RESULTS: Parameters such as area and circumference of intervertebral discs in the cross-section were not associated with the change in the efficacy index. Postoperatively, a negative correlation between the variation of the disc height, disc height index, and protrusion distance and the difference in VAS scores for low back pain at 3 and 6 months was observed among the two sagittal change parameters. Differences between changes in disc imaging parameters and postoperative efficacy were not statistically significant between various types of lumbar disc herniation. CONCLUSION: For the patients after percutaneous endoscopic lumbar discectomy, the changes in parameters such as disc area and circumference in the cross-sectional plane are not associated with efficacy, and the changes in disc height and herniation distance in the sagittal plane provide a morphologic basis for the assessment of short-term postoperative efficacy. In addition, the changes in disc morphologic parameters and postoperative efficacy do not differ between various types of lumbar disc herniation.

Endoscopic Revision Strategies and Outcomes for Recurrent L4/5 Disc Herniation After Percutaneous Endoscopic Transforaminal Discectomy.

Objective: We explore the endoscopic revision and surgical techniques for L4/5 recurrent disc herniation (rLDH) after percutaneous endoscopic transforaminal discectomy (PETD). Methods: A retrospective study was conducted. From January 2016 to September 2022, 96 patients who underwent percutaneous endoscopic lumbar discectomy for L4/5 rLDH after PETD were enrolled in the study. Based on the revision approach, the patients were divided into PETD group (57 cases) and percutaneous endoscopic interlaminar discectomy (PEID) group (39 cases). Visual Analogue Scale (VAS) for back and leg pain, Oswestry Disability Index (ODI), and modified MacNab standard were recorded to evaluate the clinical outcomes. Results: No significant differences were found in the demographic data and intraoperative blood loss between the two groups (P>0.05), but the time of operation and intraoperative X-ray fluoroscopy exposures in the PEID group were significantly less than that in the PETD group (P<0.05). The patients' postoperative clinical indexes gradually improved, and the VAS score, ODI index, and JOA score of the patients in both groups showed significant improvement compared with the preoperative period at the 1-week, 1-month, and 6-month postoperative follow-ups (P < 0.05). There was no serious complication observed during the follow-up. Conclusion: For recurrent LDH after PETD of L4/5 segments, percutaneous endoscopic revision can achieve satisfactory results. Among them, PEID has a shorter operative and fluoroscopy time and allows avoidance of the scar that forms after the initial surgery, so it can be considered preferred when both procedures can remove the disk well. However, for some specific types of herniation, a detailed surgical strategy is required.

Ultrasound-guided erector spinae plane block for awake spine surgery: A case report and review of the literature.

Percutaneous endoscopic lumbar discectomy is increasingly gaining recognition as an alternative to open microdiscectomy for the treatment of intervertebral disk herniation. Apart from the neuraxial blockade, and general anesthesia, there is literature demonstrating the performance of endoscopic lumbar discectomy under sole local anesthesia infiltration. This is particularly advantageous as an awake patient assists the surgeon by verbalizing and preventing any inadvertent nerve root damage. However, marked pain has been reported during key steps such as endoscope port installation and radiculolysis. The erector spinae plane (ESP) block is an interfascial paraspinal block that soaks the spinal nerve roots with epidural spread providing superior analgesia for endoscopic discectomy. The utility of ESP block as a perioperative analgesic technique following spine surgery is well established; there are no reports of successful endoscopic discectomy performed using this block. This article emphasizes the utility of ESP block as the sole anesthetic technique for minimally invasive spine surgery in the awake state.

Three-Dimensional Lumbosacral Reconstruction by An Artificial Intelligence-Based Automated MR Image Segmentation for Selecting the Approach of Percutaneous Endoscopic Lumbar Discectomy.

BACKGROUND: Assessing the 3-dimensional (3D) relationship between critical anatomical structures and the surgical channel can help select percutaneous endoscopic lumbar discectomy (PELD) approaches, especially at the L5/S1 level. However, previous evaluation methods for PELD were mainly assessed using 2-dimensional (2D) medical images, making the understanding of the 3D relationship of lumbosacral structures difficult. Artificial intelligence based on automated magnetic resonance (MR) image segmentation has the benefit of 3D reconstruction of medical images. OBJECTIVES: We developed and validated an artificial intelligence-based MR image segmentation method for constructing a 3D model of lumbosacral structures for selecting the appropriate approach of percutaneous endoscopic lumbar discectomy at the L5/S1 level. STUDY DESIGN: Three-dimensional reconstruction study using artificial intelligence based on MR image segmentation. SETTING: Spine and radiology center of a university hospital. METHODS: Fifty MR data samples were used to develop an artificial intelligence algorithm for automatic segmentation. Manual segmentation and labeling of vertebrae bone (L5 and S1 vertebrae bone), disc, lumbosacral nerve, iliac bone, and skin at the L5/S1 level by 3 experts were used as ground truth. Five-fold cross-validation was performed, and quantitative segmentation metrics were used to evaluate the performance of artificial intelligence based on the MR image segmentation method. The comparison analysis of quantitative measurements between the artificial intelligence-derived 3D (AI-3D) models and the ground truth-derived 3D (GT-3D) models was used to validate the feasibility of 3D lumbosacral structures reconstruction and preoperative assessment of PELD approaches. RESULTS: Artificial intelligence-based automated MR image segmentation achieved high mean Dice Scores of 0.921, 0.924, 0.885, 0.808, 0.886, and 0.816 for L5 vertebrae bone, S1 vertebrae bone, disc, lumbosacral nerves, iliac bone, and skin, respectively. There were no significant differences between AI-3D and GT-3D models in quantitative measurements. Comparative analysis of quantitative measures showed a high correlation and consistency. LIMITATIONS: Our method did not involve vessel segmentation in automated MR image segmentation. Our study's sample size was small, and the findings need to be validated in a prospective study with a large sample size. CONCLUSION: We developed an artificial intelligence-based automated MR image segmentation method, which effectively segmented lumbosacral structures (e.g., L5 vertebrae bone, S1 vertebrae bone, disc, lumbosacral nerve, iliac bone, and skin) simultaneously on MR images, and could be used to construct a 3D model of lumbosacral structures for choosing an appropriate approach of PELD at the L5/S1 level.

Percutaneous endoscopic transforaminal vs. interlaminar discectomy for L5-S1 lumbar disc herniation: a retrospective propensity score matching study.

OBJECTIVE: Percutaneous endoscopic lumbar discectomy (PELD) is a safe and effective minimally invasive surgery for treating lumbar disc herniation (LDH); however, the comparative clinical efficacy of percutaneous endoscopic transforaminal discectomy (PETD) and percutaneous endoscopic interlaminar discectomy (PEID) in treating L5-S1 LDH remains unclear. This study compared the clinical advantages of PEID and PETD for treating L5-S1 LDH. METHODS: This was a single-centre retrospective study analysing clinical data from 120 patients with L5-S1 LDH between February 2016 and May 2020. Propensity score matching (PSM) was used to adjust for imbalanced confounding variables between the two groups. Perioperative data were recorded, and clinical outcomes, including functional scores and imaging data, were compared between groups. Functional scores included visual analogue scale (VAS) for back and leg pain, Oswestry disability index (ODI), and modified MacNab criteria. Imaging data included disc height index (DHI), ratio of greyscale (RVG), and range of motion (ROM) of the responsible segment. RESULTS: After PSM, 78 patients were included in the study, and all covariates were well balanced between the two groups. In the matched patients, the PEID group showed significantly shorter surgical time (65.41 ± 5.05 vs. 84.08 ± 5.12 min) and lower frequency of fluoroscopy (2.93 ± 0.63 vs. 11.56 ± 1.54) compared with the PETD group (P < 0.001). There were no statistically significant differences in intraoperative blood loss, postoperative hospital stay, total incision length, and incidence of complications between the two groups (P > 0.05). After surgery, both groups showed significant improvement in back and leg pain based on VAS and ODI scores (P < 0.05). There were no statistically significant differences in clinical functional scores and imaging data between the two groups at various time points after surgery (P > 0.05). According to the modified MacNab criteria, the excellent and good rates in the PEID group and PETD group were 91.89% and 89.19%, respectively, with no statistically significant difference (P > 0.05). CONCLUSION: PEID and PETD have similar clinical efficacy in treating L5-S1 disc herniation. However, PEID is superior to PETD in reducing operation time and frequency of fluoroscopy.

Percutaneous endoscopic lumbar discectomy for single and double segment lumbar disc herniation with sciatic scoliosis in adults: a retrospective study.

OBJECTIVE: Sciatic scoliosis can be seen in patients with lumbar disc herniation. Percutaneous endoscopic lumbar discectomy (PELD) is a common surgical method for the treatment of lumbar disc herniation. The difference between single-segment lumbar disc herniation and double-segment lumbar disc herniation with Sciatic Scoliosis in adults after PELD needs further study. The aim of this study was to compare the imaging features of single-segment and double-segment lumbar disc herniation with Sciatic Scoliosis in adults and to further explore the clinical outcomes of functional improvement and scoliosis imaging parameters of the two groups after PELD. METHODS: Adult patients with lumbar disc herniation with sciatic scoliosis who received PELD from January 2019 to June 2022 were analyzed retrospectively. According to the number of operative segments, the patients were divided into a single-segment group and a double-segment group. Perioperative parameters were observed and compared between the two groups. The Visual Analogue Scale (VAS) score, Oswestry dysfunction index (ODI), Japanese Orthopaedic Association scores (JOA) and imaging parameters of the two groups were recorded and compared before the operation and during the follow-up. RESULTS: A total of 53 patients with single segments and 21 patients with double segments were included in this study. During the follow-up, the VAS score, ODI index and JOA score of the two groups were significantly improved as compared with those before the operation(P < 0. 05). Ninety-two point five percent of single-segment patients and 90.5% of double segment patients returned to normal scoliosis within 12 months after the operation. The operation time, number of intraoperative fluoroscopy times and the amount of intraoperative blood loss in single-segment patients were better than those in double-segment group(P < 0. 05). At the last follow-up, the AVT, CBD and SVA in the double-segment group were 5.2 ± 2.3, 5.1 ± 1.0 and 12.2 ± 3.0 mm, respectively, which were higher than those in the single-segment group (1.9 ± 0.4, 1.1 ± 1.6 and 3.9 ± 2.1 mm) (P < 0. 05). CONCLUSION: PELD is an effective treatment for single-segment and double-segment lumbar disc herniation with Sciatic scoliosis. Double-segment patients can enjoy similar clinical efficacy to single-segment patients, avoiding complications caused by decompression, fusion, and internal fixation. Scoliosis was corrected spontaneously within 12 months after operation, and the sagittal curve was significantly improved in both groups. The improvement of coronal and sagittal balance in double -segment patients may take longer.

Percutaneous Endoscopic Lumbar Discectomy for Calcified Lumbar Disc Herniation: A Retrospective Cohort Study, Systematic Review and Meta-Analysis.

BACKGROUND: Calcified lumbar disc herniation (CLDH) is a subtype characterized by calcification, leading to increased surgical complexity. Percutaneous endoscopic lumbar discectomy (PELD) is a minimally invasive technique, but its effectiveness and complications in CLDH patients remain to be fully evaluated. OBJECTIVE: To assess the effectiveness and complications of PELD in treating CLDH patients. STUDY DESIGN: A retrospective cohort study combined with a systematic review and meta-analysis. SETTING: Department of Pain Medicine, an affiliated hospital of a university. METHODS: Data from patients who underwent PELD in our department between March 2020 and May 2021 were collected. Forty CLDH patients were included in the study group, and equally matched cases with uncalcified lumbar disc herniation (UCLDH) served as controls. A systematic search was conducted on October 5, 2022, using EMBASE, PubMed, Cochrane Library, the China Biology Medicine disk, the China National Knowledge Infrastructure, and the Wanfang databases, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A random-effects model was used to calculate pooled results. RESULTS: Eighty patients were included in the retrospective cohort, and 41 studies were included in the meta-analysis. Both the retrospective cohort and meta-analysis consistently showed a significant decrease in visual analog scale (VAS) and Oswestry Disability Index (ODI) scores in the CLDH group after the operation. In the retrospective cohort, the excellent or good rate according to the MacNab classification was 85%, with no reported complications. The meta-analysis revealed a pooled excellent or good rate of 91.8% and a low complication rate of 2.9%. Combining the findings from our retrospective cohort and meta-analysis, we observed that the CLDH group had longer operation times and slightly higher postoperative ODI scores compared to the UCLDH group. LIMITATIONS: Small sample size and lack of long-term follow-up in the retrospective cohort, as well as limited inclusion of comparative studies in the meta-analysis. CONCLUSION: PELD is an effective and safe treatment option for CLDH patients. In comparison to UCLDH patients, CLDH patients may experience longer operation times and slightly slower functional recovery than those with UCLDH.

Risk factors for surgical site infection after percutaneous endoscopic lumbar discectomy.

The objective of this study was to investigate the risk factors associated with surgical site infection (SSI) after percutaneous endoscopic lumbar discectomy (PELD) in patients with lumbar disc herniation (LDH). A retrospective analysis was performed on a cohort of 335 patients who underwent PELD between January 2016 and January 2023. Data were derived from the Hospital Information System (HIS), and a comprehensive statistical assessment was performed using IBM SPSS Statistics version 25.0. Both univariate and multivariate logistic regression analyses assessed a range of risk determinants, such as age, body mass index (BMI), comorbidities, laboratory test parameters and surgery-related variables. The incidence of SSI after PELD was 2.7% (9/335). Univariate analysis highlighted BMI, diabetes mellitus, long-term corticosteroid consumption, surgical time and cerebrospinal fluid leakage as significant predictors of SSI. Multivariate logistic regression identified BMI, diabetes mellitus, long-term corticosteroid consumption, surgical time and cerebrospinal fluid leakage as significant risk factors for SSI after PELD. High BMI, diabetes mellitus, long-term corticosteroid consumption, long surgical time and postoperative cerebrospinal fluid leakage are predisposing factors for SSI in patients undergoing PELD. Precise interventions focused on such risk components, including careful preoperative assessment and strategic postoperative care, are essential to reduce the incidence of SSI and improve surgical efficacy.

Analysis of risk factors for post-operative recurrence after percutaneous endoscopic lumbar discectomy in patients with lumbar disc herniation: a meta-analysis.

BACKGROUND: This study aimed to systematically evaluate risk factors for post-operative recurrence after percutaneous endoscopic lumbar discectomy (PELD) in patients with lumbar disc herniation (LDH). METHODS: The eligible studies were retrieved from PubMed, Embase, and Web of Science databases. Quality assessment was performed. The effects of binary variables (sex, Modic change (MC), type 2 diabetes (T2DM), and smoking) on post-operative recurrence were evaluated as odds ratio (OR) and 95% confidence interval (CI). The effects of continuous variables (sagittal range of motion (SROM), body mass index (BMI), and age) were assessed as weighted mean difference (WMD) and 95% CI. Sensitivity analysis and publication bias were conducted to evaluate the reliability of pooled results. RESULTS: Eight studies were included, and their methodological quality was medium. MC (OR (95% CI) = 3.88 (2.24-6.74), P < 0.001), smoking (OR (95% CI) = 1.87 (1.45, 2.42), P < 0.001), T2DM (OR (95% CI) = 1.61 (1.12, 2.31), P = 0.010), SROM (WMD (95% CI) = 2.33 (0.95, 3.70), P = 0.001), BMI (WMD (95% CI) = 1.68 (1.37, 1.99) kg/m2, P < 0.001), and age (WMD (95% CI) = 9.95 (5.05, 14.86) years, P < 0.001) were significantly related to post-operative recurrence in patients with LDH after PELD. Significant publication bias was not observed among studies in all outcome indicators. CONCLUSION: Our findings reveal that high levels of age, BMI, and SROM, history of T2DM or smoking, or more MC may be correlated with post-operative recurrence after PELD.

Radiographic characteristics-based classification system for percutaneous endoscopic lumbar discectomy surgical approach selection in patients with L5-S1 disc herniation: a hierarchical clustering analysis.

Background: No classification system exists for aiding the selection of surgical approaches in L5-S1 disc herniation when undergoing percutaneous endoscopic lumbar discectomy (PELD). We aimed to identify radiographic subtypes to aid the selection of percutaneous endoscopic transforaminal discectomy (PETD) and percutaneous endoscopic interlaminar discectomy (PEID) in patients with L5-S1 disc herniation via unsupervised hierarchical clustering analysis. Methods: In this retrospective case-control study, we gathered 296 anteroposterior and lateral lumbar spine radiographs (dataset 1) from Tianjin Hospital between January 2016 and October 2021 for clustering analyses. Additionally, we analyzed 111 patients who underwent PEID or PETD for L5-S1 disc herniation at Tianjin Hospital from January 2016 to August 2022. We included patients with radicular leg pain or back pain associated with intra-canal disc herniation who failed in conservative treatments over 6 weeks. First, pair-wise Spearman correlation coefficients were calculated among plain radiographic metrics in dataset 1 to reveal the association among these radiographic metrics. Second, hierarchical clustering analysis was conducted to unsupervised cluster the plain films into several subtypes. Last, for each radiographic subtype, the intraoperative blood loss (IBL), operation time (OT), total operating room time (TORT) along with visual analogue scale (VAS) and Oswestry Disability Index (ODI) were compared between patients underwent PETD or PEID with age as covariates. Results: This study yielded 3 main findings: (I) iliac height (IH) was negatively correlated with intervertebral foramen width (IFW), intervertebral foramen height (IFH), and intertransverse height (ITH) (R=-0.50, -0.42, and -0.46, all P<0.001), ITH was positively correlated with IFW and IFH (R=0.40 and 0.53, all P<0.001); (II) 2 lumbosacral radiographic subtypes were identified via hierarchical clustering analysis; (III) relative to subtype 1, the patients identified as subtype 2 exhibited lesser IBL, shorter OT, and shorter TORT following PETD (t=2.92, P=0.006; t=2.65, P=0.012; t=3.17, P=0.003). Conclusions: The morphology pattern of the lumbosacral region affect the ease of different PELD procedures when performing percutaneous discectomy at the segment of L5-S1. Without considering the type of disc herniation, this classification system might aid spine surgeons in the selection of an appropriate surgical approach.

Evaluation of Augmented Reality Surgical Navigation in Percutaneous Endoscopic Lumbar Discectomy: Clinical Study.

BACKGROUND: The puncture procedure in percutaneous endoscopic lumbar discectomy (PELD) is non-visual, and the learning curve for PELD is steep. METHODS: An augmented reality surgical navigation (ARSN) system was designed and utilized in PELD. The system possesses three core functionalities: augmented reality (AR) radiograph overlay, AR puncture needle real-time tracking, and AR navigation. We conducted a prospective randomized controlled trial to evaluate its feasibility and effectiveness. A total of 20 patients with lumbar disc herniation treated with PELD were analyzed. Of these, 10 patients were treated with the guidance of ARSN (ARSN group). The remaining 10 patients were treated using C-arm fluoroscopy guidance (control group). RESULTS: The AR radiographs and AR puncture needle were successfully superimposed on the intraoperative videos. The anteroposterior and lateral AR tracking distance errors were 1.55 ± 0.17 mm and 1.78 ± 0.21 mm. The ARSN group exhibited a significant reduction in both the number of puncture attempts (2.0 ± 0.4 vs. 6.9 ± 0.5, p = 0.000) and the number of fluoroscopies (10.6 ± 0.9 vs. 18.5 ± 1.6, p = 0.000) compared with the control group. Complications were not observed in either group. CONCLUSIONS: The results indicate that the clinical application of the ARSN system in PELD is effective and feasible.

Biomechanical Finite Element Analysis of Percutaneous Endoscopic Lumbar Discectomy via a Transforaminal Approach.

OBJECTIVE: Based on the previously established 3-dimensional model, this study uses the finite element analytical method to observe the effects of superior articular process resection and intervertebral discectomy on the stress of the surgical segment under different motion states. METHODS: A validated L3-S1 finite element model was modified for simulation. And on the basis of the normal lumbar spine model, the superior articular process and discs of different parts of L4-L5 were simulated for resection. The resection models were divided into 6 groups, and the stress characteristics of articular process and discs of the lumbar spine under different postoperative motion conditions were examined under the same loading conditions. RESULTS: Simultaneous resection of the tip and base of the superior articular process increased the stress on the facet joint under various motion states compared with separate resections. In addition, the fewer herniated discs that are removed, the smaller the increase in facet joint stress. excision of the tip of the superior articular process caused a smaller stress increase in the facet joint than excision of the base under the forward bending and right-lateral flexion, and the opposite results were found under left-lateral flexion, posterior extension, and rotation. Resection of the tip of the superior articular process increases disc stress more than resection of the base of the superior articular process. CONCLUSIONS: Select resection of the superior articular process base as much as possible to expose the target of the disc. And minimize annulus damage and disc removal.