Prevention of development of postoperative dysesthesia in transforaminal percutaneous endoscopic lumbar discectomy for intracanalicular lumbar disc herniation: floating retraction technique

Access Pain During Transforaminal Endoscopic Lumbar Discectomy for Foraminal or Extraforaminal Disc Herniation

BACKGROUND/OBJECTIVES

Transforaminal endoscopic lumbar discectomy (TELD) under local anesthesia is a promising minimally invasive surgical option for intractable lumbar disc herniation (LDH). However, our understanding of access pain prediction during foraminal pathological procedures is limited. To our knowledge, no predictive rules for access pain have been established during TELD for foraminal or extraforaminal LDH. This study, with its potential for predicting access pain during TELD and discussing strategies for pain prevention and management, could significantly benefit the field of endoscopic spine surgery.

METHODS

This observational study included 73 consecutive patients who underwent TELD for foraminal or extraforaminal LDH between January 2017 and December 2022. Preoperative clinical and radiographic factors affecting significant access pain and the impact of access pain on clinical outcomes were evaluated.

RESULTS

The rate of significant access pain was 13.70% (10 of 73 patients). Extraforaminal LDH tended to cause more severe pain than did foraminal LDH during TELD under local anesthesia (p < 0.05). Although the degree of access pain was not related to global clinical outcomes, increased pain was strongly associated with prolonged operative time and length of hospital stay (p < 0.05).

CONCLUSIONS

TELD could be an effective surgical option for foraminal or extraforaminal LDH under local anesthesia. More access pain might develop during TELD for extraforaminal LDH. The extraforaminal component of LDH could narrow the safe working zone. Significant access pain might prolong the duration of surgery and hospitalization. Thus, a specialized technique is required for the clinical success of TELD.

A Modified Endoscopic Access for Lumbar Foraminal Pathologies; Posterolateral “Intertransverse” Endoscopic Approach to Minimize Postoperative Dysesthesia Following Transforaminal Approach

Objective: To present an innovative, modified endoscopic approach for foraminal/extraforaminal pathologies, to reduce postoperative dysesthesia (POD) following the conventional transforaminal endoscopic approach (the access angle more than 45° from the midline), since POD is one of the major documented disadvantages that may compromise patient satisfaction.Methods: We introduce a modified posterolateral technique, termed the intertransverse approach, utilizing a steeper access angle less than 25° through the intertransversarii muscle and the intertransverse space with expanding Kambin triangle via lateral facetectomy/foraminoplasty, to reduce dorsal root ganglion/exiting nerve root irritation under direct visualization and lower the incidence of POD. Consecutive patients undergoing endoscopic spine surgery via the intertransverse approach for foraminal and/or extraforaminal disc herniations or bony stenosis were retrospectively reviewed. Clinical outcomes were reviewed with the primary outcome being POD.Results: Twenty-two patients were included in the review. Patients showed significantly improved clinical outcomes (visual analogue scale leg and back pain and Oswestry Disability Index) postoperatively. There was a low rate of dorsal root ganglion (DRG)-related POD (9.1%, 2 of 22) that was minimal and resolved soon.Conclusion: The inter-transverse endoscopic approach is feasible for lumbosacral foraminal and extraforaminal decompression with significantly improved clinical outcomes and the added advantage of a low rate of DRG-related POD compared to traditionally reported rates in the literature for the conventional transforaminal approach.

Complications and Management of Endoscopic Spinal Surgery

In the past, the use of endoscopic spine surgery was limited to intervertebral discectomy; however, it has recently become possible to treat various spinal degenerative diseases, such as spinal stenosis and foraminal stenosis, and the treatment range has also expanded from the lumbar spine to the cervical and thoracic regions. However, as endoscopic spine surgery develops and its indications widen, more diverse and advanced surgical techniques are being introduced, and the complications of endoscopic spine surgery are also increasing accordingly. We searched the PubMed/MEDLINE databases to identify articles on endoscopic spinal surgery, and key words were set as “endoscopic spinal surgery,” “endoscopic cervical foramoinotomy,” “PECD,” “percutaneous transforaminal discectomy,” “percutaneous endoscopic interlaminar discectomy,” “PELD,” “PETD,” “PEID,” “YESS” and “TESSYS.” We analyzed the evidence level and classified the prescribed complications according to the literature. Endoscopic lumbar surgery was divided into full endoscopic interlaminar and transforaminal approaches and a unilateral biportal approach. We performed a comprehensive review of available literature on complications of endoscopic spinal surgery. This study particularly focused on the prevention of complications. Regardless of the surgical methods, the most common complications related to endoscopic spinal surgery include dural tears and perioperative hematoma. transient dysesthesia, nerve root injury and recurrence. However, Endoscopic spinal surgery, including full endoscopic transforaminal and interlaminar and unilateral biportal approaches, is a safe and effective a treatment for lumbar as well as cervical and thoracic spinal diseases such as disc herniation, lumbar spinal stenosis, foraminal stenosis and recurrent disc herniation.

Bibliographic Study and Meta-Analysis of Clinical Outcomes of Full-Endoscopic Spine Surgery for Painful Lumbar Spine Conditions

BACKGROUND

Full-endoscopic spine surgery (FESS) indications already cover degenerative, infectious, and neoplastic diseases. This study aimed to use a bibliometric search and meta-analysis of the highest-quality studies in the last 20 years to determine the quantity and quality of FESS research, geographic distribution, and the outcomes for lumbar conditions.

METHODS

Articles on FESS published from 2000 to 2022 were screened and assessed through Web of Science, PubMed, and Scopus. Also, databases were searched for longitudinal studies to pool in a meta-analysis of patients undergoing FESS for lumbar conditions. After stratifying the risk of bias and having collected the studies of the highest quality, we included the proportion of patients with a satisfactory outcome and intraoperative and postoperative adverse events after the analysis of lumbar spine conditions.

RESULTS

A total of 728 articles were identified by the bibliographic search. Between 2000 and 2021, the published articles increased 21-fold. Most were from China (70.15%), followed by South Korea (19.5%). Most were retrospective (68.3%) and regarding treatment of lumbar disease (86.4%). Fifty studies, including 34,828 patients, were pooled in the meta-analysis. More than 85% of patients experienced satisfactory improvement in each of different lumbar conditions. Major adverse events were <2%; recurrence and postoperative dysesthesia rates were within those reported for open or mini-invasive procedures.

CONCLUSIONS

This study may fill research gaps on FESS and lead to adequately designed studies. Our meta-analysis showed that FESS for lumbar diseases is a procedure with satisfactory outcomes and low rates of adverse events.

Clinical comparison of percutaneous transforaminal endoscopic discectomy and unilateral biportal endoscopic discectomy for single-level lumbar disc herniation

Purpose

To compare the clinical outcomes of percutaneous transforaminal endoscopic discectomy (PTED) and unilateral biportal endoscopic discectomy (UBE) for the treatment of single-level lumbar disc herniation (LDH).

Materials and methods

From January 2020 to November 2021, 62 patients with single-level LDH were retrospectively reviewed. All patients underwent spinal surgeries at the Affiliated Hospital of Chengde Medical University and Beijing Tongren Hospital, Capital Medical University. Among them, 30 patients were treated with UBE, and 32 were treated with PTED. The patients were followed up for at least one year. Patient demographics and perioperative outcomes were reviewed before and after surgery. The Oswestry Disability Index (ODI), visual analog scale (VAS) for back pain and leg pain, and modified MacNab criteria were used to evaluate the clinical outcomes. x-ray examinations were performed one year after surgery to assess the stability of the lumbar spine.

Results

The mean ages in the UBE and PTED groups were 46.7 years and 48.0 years, respectively. Compared to the UBE group, the PTED group had better VAS scores for back pain at 1 and 7 days after surgery (3.06 ± 0.80 vs. 4.03 ± 0.81, P < 0.05; 2.81 ± 0.60 vs. 3.70 ± 0.79, P < 0.05). The UBE and PTED groups demonstrated significant improvements in the VAS score for leg pain and ODI score, and no significant differences were found between the groups at any time after the first month (P > 0.05). Although the good-to-excellent rate of the modified MacNab criteria in the UBE group was similar to that in the PTED group (86.7% vs. 87.5%, P > 0.05), PTED was advantageous in terms of the operation time, estimated blood loss, incision length, and length of postoperative hospital stay.

Conclusions

Both UBE and PTED have favorable outcomes in patients with single-level LDH. However, PTED is superior to UBE in terms of short-term postoperative back pain relief and perioperative quality of life.

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.

Uniportal Full-Endoscopic versus Minimally Invasive Decompression for Lumbar Spinal Stenosis: A Meta-analysis

BACKGROUND

 In this study, we systematically analyze the effectiveness of the uniportal full-endoscopic (UPFE) and minimally invasive (MIS) decompression for treatment of lumbar spinal stenosis patients.

METHODS

 We performed a systematic search in Medline, Embase, Europe PMC, PubMed, Web of Science, Cochrane databases, Chinese Biomedical Literature Database, China national knowledge infrastructure, and Wanfang Data databases for all relevant studies. All statistical analyses were performed using Review Manager version 5.3.

RESULTS

 A total of 9 articles with 522 patients in the UPFE group and 367 patients in the MIS group were included. The results of the meta-analysis showed that the UPFE group had significantly better results in hospital stay time (mean difference [MD]: -2.05; 95% confidence interval [CI]: -2.87 to -1.23), intraoperative blood loss (MD: -36.56; 95% CI: -54.57 to -18.56), and wound-related complications (MD: -36.56; 95%CI: -54.57 to -18.56) compared with the MIS group, whereas the postoperative clinical scores (MD: -0.66; 95%CI: -1.79 to 0.47; MD: -0.75; 95%CI: -1.86 to 0.36; and MD: -4.58; 95%CI: -16.80 to 7.63), satisfaction rate (odds ratio [OR] = 1.24; 95%CI: 0.70-2.20), operation time (MD: 30.31; 95%CI: -12.55 to 73.18), complication rates for dural injury (OR = 0.60; 95%CI: 0.29-1.26), epidural hematoma (OR = 0.60; 95%CI: 0.29-1.26), and postoperative transient dysesthesia and weakness (OR = 0.73; 95%CI: 0.36-1.51) showed no significant differences between the two groups.

CONCLUSIONS

 The UPFE decompression is associated with shorter hospital stay time and lower intraoperative blood loss and wound-related complications compared with MIS decompression for treatment of lumbar spinal stenosis patients. The postoperative clinical scores, satisfaction rate, operation time, complication rates for dural injury, epidural hematoma, and postoperative transient dysesthesia and weakness did not differ significantly between two groups.

A Postoperative Phenomenon of Percutaneous Endoscopic Lumbar Discectomy: Rebound Pain

OBJECTIVE

After percutaneous endoscopic lumbar discectomy (PELD), most patients with lumbar disc herniation (LDH) experience relief from the typical symptoms of low back and leg pain. However, for a small number of patients, these symptoms are relieved immediately after surgery but aggravated soon after, and then relieved after short-term full rest or conservative treatment. The aim of the study was to demonstrate this short-term recurrent phenomenon, termed rebound pain.

METHODS

A retrospective study was conducted on 144 patients who underwent single-segment PELD from May 2017 to June 2020. Postoperative patients were divided into a rebound pain group and a non-rebound pain group. For the former group, general information, symptom characteristics and visual analogue score (VAS) changes in rebound pain were summarized. For both groups, postoperative efficacy was evaluated by recent VAS of low back and leg pain in the remission stage, the Oswestry disability index (ODI) and the modified MacNab criteria at the last follow-up. Logistic regression analysis was used to identify predictors for rebound pain.

RESULTS

The VAS and ODI exhibited significant improvements at the last follow-up of average 15.4 months (P < 0.001). The successful outcomes according to the modified MacNab criteria reached 94.4%. A total of 15 patients (10.4%) experienced rebound pain. The typical feature was pain that usually began within 1 month after surgery and lasted for less than 1 month. The symptoms were mainly leg pain with or without low back pain. The range of pain was equal to or less than that before surgery. The symptoms were relieved after conservative treatment. In logistic regression model, postoperative return-to-work time > 45 days was found as a protective factor for rebound pain (p = 0.031).

CONCLUSION

Although rebound pain with multiple characteristics and a short duration had no significant effect on long-term postoperative efficacy, its high incidence often caused unnecessary concern in both patients and doctors. As a result, careful differentiation of rebound pain from other postoperative complications is needed.

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

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

Application of a targeted and quantificational foraminoplasty device in percutaneous transforaminal endoscopic discectomy for L5-S1 disc herniation: preliminary clinical outcomes

OBJECTIVE

Percutaneous transforaminal endoscopic discectomy (PTED) is minimally invasive and has been widely used to treat patients with lumbar disc herniation (LDH) due to its safety and efficiency. However, due to the unique anatomy of the L5-S1 level, the PTED procedure is often difficult to perform in the region. ZESSYS, a targeted and quantificational foraminoplasty device, may help to overcome these anatomical limitations. In this study, we assessed the efficiency and the short-term effects of PTED with ZESSYS at the L5-S1 level.

METHODS

Between January and August of 2018, fifty-six patients with lumbar disc herniation at the single level of L5-S1 and who underwent percutaneous transforaminal endoscopic discectomy were enrolled in this retrospective cohort study. They were segregated into the transforaminal endoscopic surgical system (TESSYS) group and the ZESSYS group. The puncture time, foraminoplasty time, decompression time, and fluoroscopy time were evaluated for operation efficiency. Clinical outcomes were assessed by the visual analog scale (VAS) score and Oswestry Disability Index (ODI) score. The MacNab criteria were used to evaluate patient subjective satisfaction at 12-month follow-up postoperatively.

RESULTS

The average puncture time (5.29 ± 2.05 min), foraminoplasty time (12.82 ± 2.52 min), and fluoroscopy time (26.29 ± 5.96 s) were all significantly shorter in the ZESSYS group than in the TESSYS group (average puncture time 8.07 ± 3.13 min, p < 0.01; foraminoplasty time, 17.18 ± 2.92 min, p < 0.01; fluoroscopy time, 34.73 ± 6.86 s; p < 0.01). No significant differences were observed between the 2 groups in the decompression time (p = 0.057). The VAS score of low back pain and leg pain, as well as the ODI score, improved at all time points postoperatively compared with preoperative, in both the TESSYS group and the ZESSYS group (P < 0.05). There were no significant differences in the VAS score of low back pain, VAS score of leg pain, and ODI score between the TESSYS group and the ZESSYS group at the same time points (P > 0.05). According to the MacNab criteria, the excellent and good rate at 12-month follow-up postoperatively was 85.7% in the TESSYS group and 89.3% in the ZESSYS group (P > 0.05).

CONCLUSION

The targeted and quantificational foraminoplasty device named ZESSYS was more efficient in the puncture and foraminoplasty procedures, effectively protecting the exiting nerve and minimizing the level of radiation exposure. The device is efficient and safe for PTED in treating lumbar disc herniation at the L5-S1 level.

Endoscopic and Microscopic Interlaminar Discectomy for the Treatment of Far-Migrated Lumbar Disc Herniation: A Retrospective Study with a 24-Month Follow-Up

Purpose

Percutaneous endoscopic lumbar discectomy for the treatment of far-migrated lumbar disc herniation (LDH) is clinically challenging. The aim of this study was to compare the efficacy and safety of interlaminar endoscopic lumbar discectomy (IELD) and interlaminar microscopic lumbar discectomy (IMLD) for the treatment of far-migrated LDH.

Materials and Methods

We retrospectively analyzed 50 consecutive cases of far-migrated LDH treated by IELD or IMLD. Clinical data and outcomes were assessed before the operation and 1 day and 3, 12, and 24 months after the surgery using the visual analog scale (VAS) and Oswestry disability index (ODI). Modified MacNab criteria were used to evaluate patient satisfaction at the 24-month follow-up.

Results

A significant reduction in leg pain and improvement in ODI (P<0.01) were observed in both groups after surgery. Lower back pain (LBP) was reduced at 24 months postsurgery in the IELD group (P<0.05) but not in the IMLD group (P>0.05). There were significant intergroup differences in VAS LBP score at 1 day and 24 months postsurgery (p=0.01 and 0.02, respectively) and in ODI at 24 months (p=0.03). The rate of excellent or good outcome was 90.32% with IELD and 78.95% with IMLD (p=0.55). Hospital stay and time to ambulation were shorter in the IELD group than in the IMLD group, but the former had a longer operative time (p<0.01). Low and comparable complication rates were reported in the IELD (16.13%) and IMLD (10.53%) groups (p=0.70).

Conclusion

Both IELD and IMLD achieve favorable clinical results in the treatment of far-migrated LDH, with only minor complications. Compared to IMLD, LBP was significantly reduced with IELD presumably because it involved less trauma.

The Novel Technique of Uniportal Endoscopic Interlaminar Contralateral Approach for Coexisting L5-S1 Lateral Recess, Foraminal, and Extraforaminal Stenosis and Its Clinical Outcomes

BACKGROUND

Multifocal intra-and-extraspinal lumbar stenotic lesions could be decompressed with one endoscopic surgical approach, which has the advantages of functional structure preservation, technical efficacy, and safety.

METHODS

A retrospective study was performed on 48 patients who underwent uniportal endoscopic contralateral approach due to coexisting lateral recess, foraminal, and extraforaminal stenosis at the L5-S1 level. Foraminal stenosis grade and postoperative dysesthesia (POD) were analyzed. Visual analog scale (VAS) pain scores, modified Oswestry Disability Index (ODI) scores, and MacNab criteria for evaluating pain disability and response were analyzed.

RESULTS

The foraminal stenosis grade of the treated spinal levels was grade 1 (n = 16, 33%), grade 2 (n = 20, 42%), and grade 3 (n = 12, 25%). The rate of occurrence of POD grade 2 and above, which may be related to intraoperative dorsal root ganglion (DRG) retraction injury, was revealed to be 4.2% (two with grade 2, none with grade 3). The patients showed favorable clinical outcomes.

CONCLUSIONS

Uniportal endoscopic interlaminar contralateral approach is an effective procedure to resolve combined stenosis (lateral recess, foraminal, and extraforaminal region) with one surgical approach at the L5-S1 level. It may be a minimal DRG retracting and facet joint preserving procedure in foraminal and extraforaminal decompression.

Effect of Dorsal Root Ganglion Retraction in Endoscopic Lumbar Decompressive Surgery for Foraminal Pathology: A Retrospective Cohort Study of Interlaminar Contralateral Endoscopic Lumbar Foraminotomy and Discectomy versus Transforaminal Endoscopic Lumbar Foraminotomy and Discectomy

OBJECTIVE

Postoperative dysesthesia (POD) is a common complication in surgery involving foraminal diseases, including lumbar foraminal or extraforaminal herniated nucleus pulposus (HNP). Minimal dorsal root ganglion (DRG) retraction is key to preventing POD. We compared the clinical results, safety, and efficacy between the paraspinal transforaminal approach requiring DRG retraction and the interlaminar contralateral approach without DRG retraction for foraminal and extraforaminal diseases.

METHODS

A retrospective cohort study was performed of 50 patients who underwent uniportal transforaminal endoscopic lumbar foraminotomy and discectomy (TELD) and 50 patients who underwent anuniportal interlaminar contralateral endoscopic lumbar foraminotomy and discectomy (ICELF) because of lumbar foraminal HNP. The operated levels, combined degenerative diseases, postoperative complications, and POD were analyzed. The visual analog scale (VAS) pain scores, modified Oswestry Disability Index, and MacNab criteria for evaluating pain disability and response were analyzed.

RESULTS

In the ICELF group (total, n = 7, 14%), there were 5 (10%) and 2 (4%) patients with POD grade 1 and 2, respectively. In the TELD group (total, n = 13, 26%), there were 7 (14%), 5 (10%), and 1 (2%) patients with POD grade 1, 2, and 3, respectively. The overall occurrence rate of grade 2 and greater POD was higher in the TELD group (n = 6, 12%) than in the ICELF group (n = 2, 4%). In the ICELF group, 3 of 9 patients (33%) with combined canal structure deforming diseases had POD, of whom none had POD of grade 2 and greater. In the TELD group, 4 of 7 patients (57%) with combined canal structure deforming diseases had POD, of whom all had POD of grade 2 and greater. Two surgical groups showed favorable clinical outcomes with the visual analog scale, Oswestry Disability Index, and MacNab criteria.

CONCLUSIONS

Both TELD and ICELF were found to treat foraminal or extraforaminal HNP with good clinical outcomes. ICELF might have a lower POD rate in complicated cases such as adjacent segment disease, degenerative spondylolisthesis, and isthmic spondylolisthesis. This surgical procedure could be an alternative in complicated cases or in patients with an anatomically limited L5-S1 level. However, the procedure is technically challenging to perform.

Feasibility of Using Intraoperative Neuromonitoring in the Prophylaxis of Dysesthesia in Transforaminal Endoscopic Discectomies of the Lumbar Spine

(1) Background: Postoperative nerve root injury with dysesthesia is the most frequent sequela following lumbar endoscopic transforaminal discectomy. At times, it may be accompanied by transient and rarely by permanent motor weakness. The authors hypothesized that direct compression of the exiting nerve root and its dorsal root ganglion (DRG) by manipulating the working cannula or endoscopic instruments may play a role. (2) Objective: To assess whether intraoperative neurophysiological monitoring can help prevent nerve root injury by identifying neurophysiological events during the initial placement of the endoscopic working cannula and the directly visualized video endoscopic procedure. (3) Methods: The authors performed a retrospective chart review of 65 (35 female and 30 male) patients who underwent transforaminal endoscopic decompression for failed non-operative treatment of lumbar disc herniation from 2012 to 2020. The patients’ age ranged from 22 to 86 years, with an average of 51.75 years. Patients in the experimental group (32 patients) had intraoperative neurophysiological monitoring recordings using sensory evoked (SSEP), and transcranial motor evoked potentials (TCEP), those in the control group (32 patients) did not. The SSEP and TCMEP data were analyzed and correlated to the postoperative course, including dysesthesia and clinical outcomes using modified Macnab criteria, Oswestry disability index (ODI), visual analog scale (VAS) for leg and back pain. (4) Results: The surgical levels were L4/L5 in 44.6%, L5/S1 in 23.1%, and L3/L4 in 9.2%. Of the 65 patients, 56.9% (37/65) had surgery on the left, 36.9% (24/65) on the right, and the remaining 6.2% (4/65) underwent bilateral decompression. Postoperative dysesthesia occurred in 2 patients in the experimental and six patients in the control group. In the experimental neuromonitoring group, there was electrodiagnostic evidence of compression of the exiting nerve root’s DRG in 24 (72.7%) of the 32 patients after initial transforaminal placement of the working cannula. A 5% or more decrease and a 50% or more decrease in amplitude of SSEPs and TCEPs recordings of the exiting nerve root were resolved by repositioning the working cannula or by pausing the root manipulation until recovery to baseline, which typically occurred within an average of 1.15 min. In 15 of the 24 patients with such latency and amplitude changes, a foraminoplasty was performed before advancing the endoscopic working cannula via the transforaminal approach into the neuroforamen to avoid an impeding nerve root injury and postoperative dysesthesia. (5) Conclusion: Neuromonitoring enabled the intraoperative diagnosis of DRG compression during the initial transforaminal placement of the endoscopic working cannula. Future studies with more statistical power will have to investigate whether employing neuromonitoring to avoid intraoperative compression of the exiting nerve root is predictive of lower postoperative dysesthesia rates in patients undergoing videoendoscopic transforaminal discectomy.

Micro-anatomical structures of the lumbar intervertebral foramen for full-endoscopic spine surgery: review of the literatures

Percutaneous endoscopic lumbar discectomy (PELD) is a minimally invasive spinal surgical technique. PELD can be performed via 2 routes, transforaminal (TF) or interlaminar. The TF approach is a well-established modality in the treatment of patients with herniated lumbar discs. This technique makes the most of the space within the intervertebral foramen where, as Kambin claimed, the safe approach to the lesion is possible. Knowledge of the lumbar artery with its branches and various ligaments of anatomies of the intervertebral foramen are needed to perform successful surgeries and to reduce complications.

Dysethesia due to irritation of the dorsal root ganglion following lumbar transforaminal endoscopy: Analysis of frequency and contributing factors

BACKGROUND

New onset of acute dysethetic leg pain due to irritation of the dorsal root ganglion (DRG) following uneventful recovery from an expertly executed lumbar transforaminal endoscopic decompression is a common problem. Its incidence and relation to any risk factors that could be mitigated preoperatively are not well understood.

METHODS

We performed a multicenter frequency analysis of DRG irritation dysesthesia in 451 patients who underwent lumbar transforaminal endoscopic decompression for herniated disc and foraminal stenosis. The 451 patients consisted of 250 men and 201 women with an average age of 55.77 ± 15.6 years. The average follow-up of 47.16 months. The primary clinical outcome measures were the modified Macnab criteria. Chi-square testing was employed to analyze statistically significant associations between increased dysesthesia rates, preoperative diagnosis, the surgical level(s), and surgeon technique.

RESULTS

At final follow-up, Excellent (183/451; 40.6 %) and Good (195/451; 43.2 %) Macnab outcomes were observed in the majority of patients (378/451; 83.8 %). The majority of study patients (354; 78.5 %) had an entirely uneventful postoperative recovery without any DRG irritation, but 21.5 % of patients were treated for it in the immediate postoperative recovery period with supportive care measures including activity modification, transforaminal epidural steroid injections, non-steroidal anti-inflammatories, gabapentin, or pregabalin. There was no statistically significant difference in dysesthesia rates between lumbar levels from L1 to S1, or between single (DRG rate 21.8 %) or two-level (DRG rate 20.2 %) endoscopic decompression (p = 0.742). A statistically significantly higher incidence of postoperative dysesthesia was observed in patients who underwent decompression for foraminal stenosis (38/103; 27 %), and recurrent herniated disc (7/10; 41.2 %; p = 0.039). There were also statistically significant variations in dysesthesia rates between the seven participating clinical study sites ranging from 11.6%-33% (p = 0.002). Unrelenting postoperative dysesthetic leg pain due to DRG irritation was statistically associated with less favorable long-term clinical outcomes with DRG rates as high as 45 % in patients with a Fair and 61.3 % in patients with Poor Macnab outcomes (p < 0.0001).

CONCLUSIONS

Postoperative dysesthesia following transforaminal endoscopic decompression should be expected in one-fifth of patients. There was no predilection for any lumbar level. Foraminal stenosis and recurrent herniated disc surgery are risk factors for higher dysesthesia rates. There was a statistically significant variation of dysesthesia rates between participating centers suggesting that the surgeon skill level is of significance. Severe postoperative dysesthesia may be a predictor of Fair of Poor long-term Macnab outcomes.

Transforaminal approach versus interlaminar approach: A meta-analysis of operative complication of percutaneous endoscopic lumbar discectomy

BACKGROUND

To systematically analyze the differences of complications between percutaneous transforaminal endoscopic discectomy (PTED) and percutaneous interlaminar endoscopic discectomy (PIED) in the treatment of lumbar disc herniation.

METHODS

We performed a systematic search in MEDLINE, EMBASE, PubMed, Web of Science, Cochrane databases, Chinese Biomedical Literature Database, CNKI, and Wanfang Data for all relevant studies. All statistical analysis was performed using Review Manager Version 5.3.

RESULTS

A total of 15 articles with 1156 study subjects were included, with 550 patients in PTED group and 606 patients in PIED group. The results of the meta-analysis showed that postoperative dysesthesia (odds ratio [OR] = 0.61, 95% confidence interval [CI], 0.33-1.13), nerve root injury (OR = 1.22, 95% CI, 0.30-5.02), surgical site wound complications (OR = 1.26, 95% CI, 0.29-5.40), recurrence (OR = 1.09, 95% CI, 0.54-2.21), conversion to open surgery (OR = 1.26, 95% CI, 0.33-4.81), incomplete decompression (OR = 1.62, 95% CI, 0.43-6.09), and total complication (OR = 0.72, 95% CI, 0.49-1.06) showed no significant differences between the PTED group and the PIED group, while the PTED group had significantly better results in dural tear compared with the PIED group (OR = 0.31, 95% CI, 0.13-0.79).

CONCLUSIONS

Dural tear was significantly less occured in PTED compared with PIED. The postoperative dysesthesia, nerve root injury, surgical site wound complications, recurrence, conversion to open surgery, incomplete decompression, and total complication did not differ significantly between PTED and PIED in the treatment of lumbar disc herniation.

Percutaneous endoscopic lumbar discectomy for lumbar disc herniation as day surgery - short-term clinical results of 235 consecutive cases

Many studies have reported the good outcomes of percutaneous endoscopic lumbar discectomy (PELD) for the treatment of lumbar disc herniation (LDH). However, the majority of published studies on PELD showed an average hospital stay of 2 to 5 days. Thus, the purpose of this retrospective study was to evaluate and compare the clinical outcomes of patients undergoing PELD for LDH as day surgery with the outcomes of patients managed as inpatients.A total of 402 patients who underwent PELD for single-level LDH were included. The visual analog scale score (VAS) for leg and back pain, Oswestry Disability Index (ODI) score, and Macnab criteria were evaluated preoperatively and at 2 years postoperatively (final follow-up). Operation time, duration of hospital stay, cost, postoperative complications, and the rates of and reasons for delayed discharge and readmission were recorded and analyzed.The mean operative time was 45.8 ± 8.4 minutes in the PELD-A (nonday surgery mode) group and 41.3 ± 8.7 minutes in the PELD-D (day surgery mode) group (P = .63). The average duration of hospital stay was 2.8 ± 1.1 days in the PELD-A group and 3.2 ± 0.9 hours in the PELD-D group (P < .001). The average hospitalization expenses of the PELD-A and PELD-D groups were 28,090 ± 286 RMB and 24,356 ± 126 RMB (P = .03), respectively. In both groups, the mean VAS and ODI scores improved significantly postoperatively compared with the preoperative scores. The satisfactory result rate was 89.8% in the PELD-D group and 91.0% in the PELD-A group, without a significant difference (P = .68). The delayed discharge rate in the PELD-A and PELD-D groups was 8.20% and 8.43%, respectively (P = .93). The main reasons for delayed discharge were dysesthesia, neurologic deficit, nausea, headache and residential distance from the hospital. The overall readmission rates were 5.99% and 5.53% in the PELD-A and PELD-D groups, respectively (P = .85). The most common reasons for readmission were reherniation, sequestered herniation and pain.In conclusion, PELD is safe and effective for the treatment of LDH and can reduce medical costs as day surgery, and it thus warrants increased attention.

Current techniques of endoscopic decompression in spine surgery

Endoscopic spine surgery has become a practical, minimally invasive technique for decompression in patients with spinal disc herniation or stenosis. This review aimed to summarize the current techniques of endoscopic decompression technique in spine surgery and to discuss the benefits, limitations, and future perspectives of this minimally invasive technique. Endoscopic spine decompression surgery can be categorized according to the endoscopic property: percutaneous endoscopic (full-endoscopic), microendoscopic, and biportal endoscopic. It can also be classified based on the approach: transforaminal, interlaminar, anterior, posterior, and caudal approaches. Theoretically, each technique can be applied in the lumbar, cervical, and thoracic spine. The various endoscopic spine surgery techniques should be appropriately conducted according to the disease entities, level, and zone of pathologies. Although the current level of evidence is relatively low and the relevance of the technique is controversial, recent clinical results and the critical concept are promising. Development in optics, instruments, and approach will improve its safety and reduce technical complexity. In the meantime, high-quality clinical studies, including randomized trials and meta-analyses, are due for publication. Eventually, endoscopic spine surgery is expected to become the golden standard for spinal surgery.

[Percutaneous full-endoscopic bilateral decompression via unilateral posterior approach for lumbar spinal stenosis]

OBJECTIVE

To design the surgical strategy of percutaneous full-endoscopic bilateral decompression via unilateral posterior approach for bilateral lumbar spinal stenosis (LSS) and to evaluate the effectiveness.

METHODS

The percutaneous full-endoscopic bilateral decompression via unilateral posterior approach for bilateral LSS was designed according to the pathological features of LSS. The technique was used to treat 42 patients with LSS between January 2016 and January 2018. There were 18 males and 24 females with an average age of 61.7 years (range, 46-81 years). The duration of symptoms was 1-20 years, with an average of 9.7 years. The surgical segment at L 4, 5 were 27 cases, at L 5, S 1 were 15 cases. The operation time and perioperative complications were recorded. Lumbar X-ray, CT, and MRI examinations were performed at 1 week, 3 months, and 1 year after operation. Visual analogue scale (VAS) score was used to evaluate the low back pain and leg pain, Oswestry disability index (ODI) was used to evaluate the lumbar function, and single continuous walking distance (SCWD) was used to evaluate lower extremity nerve function. The clinical efficacy was evaluated by MacNab criteria at 1 year after operation.

RESULTS

All patients underwent surgery successfully. The operation time was 68-141 minutes with an average of 98.2 minutes. All 42 patients were followed up 12-24 months with an average of 18.8 months. There were 2 cases of dural tears during operation, and 1 case of transient dysfunction of the lower limbs of the decompression channel after operation. All of them were cured after corresponding treatment. No serious complications such as death, major bleeding, or irreversible nerve injury occurred during follow-up. No segmental instability was found according to postoperative lumbar hyperextension and flexion X-ray films, and postoperative CT and MRI imaging showed that the stenotic lumbar spinal canal was significantly enlarged, and the compression of the nerve root was sufficient. The VAS score of low back pain and leg pain, ODI score, and SCWD at each time point after operation were significantly improved when compared with those before operation ( P<0.05); the indexes were significantly improved over time after operation, and the differences were significantly ( P<0.05). The clinical efficacy was evaluated by MacNab standard at 1 year after operation, and the results were excellent in 18 cases, good in 20 cases, fair in 3 cases, and poor in 1 case. The excellent and good rate was 90.5%.

CONCLUSION

The percutaneous full-endoscopic bilateral decompression via unilateral posterior approach for LSS is a safe and effective procedure. A well-designed surgical strategy and mastery of its technical points are important guarantees for successful operation and satisfactory results.

Five-year outcomes and predictive factors of transforaminal full-endoscopic lumbar discectomy

Although several studies have reported the effectiveness of transforaminal full-endoscopic lumbar discectomy (TELD), no cohort study on the long-term outcomes of TELD has been conducted. Thus, this study aimed to evaluate the long-term clinical outcomes of TELD and to determine the factors predicting favorable outcome.Five-year longitudinal data of 204 consecutive patients who underwent TELD were collected. Outcomes were assessed using the visual analog scale (VAS) pain score, Oswestry disability index (ODI), patient satisfaction rating, and the modified Macnab criteria.The mean VAS score for leg pain improved from 7.64 at the baseline to 1.71, 0.81, 0.90, and 0.99 at postoperative 6 weeks, 1 year, 2 years, and 5 years, respectively (P <.001). The mean ODI improved from 67.2% at the baseline to 15.7%, 8.5%, 9.4%, and 10.1% at postoperative 6 weeks, 1 year, 2 years, and 5 years, respectively (P <.001). The overall patient satisfaction rate was 94.1%. Based on the modified Macnab criteria, 83.8% of patients had excellent or good results. In this study, younger patients with intracanal disc herniation tended to have better outcomes than elderly patients with foraminal/far-lateral disc herniation (P <.05).Transforaminal endoscopic lumbar discectomy offers favorable long-term outcomes with minimal tissue damage. Postoperative pain and functional status may change over time. Proper patient selection remains essential for the success of this minimally invasive procedure.

[Effect and effectiveness analysis of different approaches of transforaminal endoscope on extirpation amount of nuclues pulposus]

Objective

To investigate the effect and effectiveness analysis of different approaches of transforaminal endoscope on extirpation amount of nuclues pulposus.

Methods

Between August 2011 and December 2014, a total of 165 patients with lumbar disc herniation were retrospectively enrolled and were treated with nucleus pulposus discectomy through transforaminal endoscope. The patients were randomly divided into 4 groups according to different approach of transforaminal endoscope. The posterolateral approach (Yeung's technology) was used in group A (42 cases), transforaminal endoscopic spine system (TESSYS) technology was used in group B (40 cases), improved transforaminal endoscopic access (ITEA) technology was used in group C (43 cases), and interlaminar approach (40 cases) was used in group D (40 cases). There was no significant difference in gender, age, disease duration, symptomatic side, and segments among 4 groups ( P>0.05). The extirpation amount of nuclues pulposus was calculated and compared among 4 groups; the effectiveness was evaluated by pre- and post-operative visual analogue scale (VAS) score, Oswestry disability index (ODI), lumbar curvature index (LCI), and intervertebral height.

Results

The discectomy amount of nucleus pulposus was (3.7±0.8), (3.6±0.7), (4.5±1.1), and (3.0±0.8) cm ³ in groups A, B, C, and D, respectively. The amount of group C was significantly larger than that of the other 3 groups ( P<0.05), and the amount of group D was significantly smaller than that of the other 3 groups ( P<0.05); no significant difference was found between groups A and B ( P>0.05). Cerebrospinal fluid leakage was found in 1 case; no other postoperative complications including intervertebral space infection and epidural hematoma was found. All the incisions healed by first intension. All the patients were followed up 12-24 months (mean, 18 months), and no typical symptoms of recurrence was found during the follow-up period. There was no significant difference in preoperative lower back pain VAS score, lower extremities VAS score, and ODI scores among 4 groups ( P>0.05). The above scores at last follow-up were significantly improved when compared with preoperative ones in each group ( P<0.05), but no significant difference of above scores and recovery values was found among 4 groups ( P>0.05). The difference in LCI and intervertebral height at preoperation and at last follow-up were not significant between 4 groups ( P>0.05). The difference in LCI and intervertebral height of each group between at preoperation and last follow-up were not significant ( P>0.05). And the recovery value of LCI and the lost of height at last follow-up also showed no significant differences between 4 groups ( P>0.05).

Conclusion

The ITEA technology can give a wider field of view than other technologies. It is more convenient to find and remove the nucleus pulposus. However, the appropriate operative approaches should be chosen according to the symptoms and characteristics of lumbar disc herniation.

Short-term clinical efficacy of percutaneous transforaminal endoscopic discectomy in treating young patients with lumbar disc herniation

Background

In the last decades, full-endoscopic techniques to treat lumbar disc herniation (LDH) have gained popularity in clinical practice. However, few studies have described the safety and efficacy of percutaneous transforaminal endoscopic discectomy (PTED) in treating younger patients with LDH. This study aims to evaluate the preliminary surgical outcome and complication of PTED in treating younger patients with LDH.

Methods

Between June 2012 and June 2016, 72 young patients (< 45 years old) who underwent PTED for single-level LDH were prospectively followed up. All patients were followed up for at least 12 months (range 12–35 months). Pain was measured using visual analogue scale (VAS) scores. Patient satisfaction was evaluated using the MacNab outcome scale. Clinical outcomes were measured preoperatively, at 2 days and 6 months, and 12 months postoperatively.

Results

The mean VAS score for back pain was 5.1 ± 2.3 preoperatively and 3.1 ± 1.2, 2.1 ± 0.5, and 2.0 ± 0.7 at 2 days, 6 months, and 12 months postoperatively, respectively. The VAS score for leg pain was 7.1 ± 2.6 preoperatively and 3.0 ± 1.1, 2.1 ± 1.3, and 1.9 ± 0.8 at 2 days, 6 months, and 12 months postoperatively, respectively. These postoperative scores were all significantly different when compared with preoperative scores (P < 0.001). According to the modified MacNab outcome scale, excellent was obtained in 43 patients, good was obtained in 25 patients, and fair was obtained in 4 patients, and 94.44% of these patients had excellent and good outcomes at the final follow-up. There were no complications related to surgery, and no spinal instability was detected.

Conclusion

PTED appears to be an effective and safe intervention for younger patients with LDH. High-quality randomized controlled trials are required to further study the efficacy and safety of PTED in treating younger patients with LDH.

Analysis of Clinical Results of Three Different Routes of Percutaneous Endoscopic Transforaminal Lumbar Discectomy for Lumbar Herniated Disk

OBJECTIVE

Percutaneous endoscopic transforaminal lumbar discectomy (PETLD) can be performed by using foraminal, intervertebral, and suprapedicular routes. The aim of this study was to assess clinical results of three different routes of PETLD.

METHODS

One hundred eleven patients who underwent PETLD between January 2016 and October 2016 were included in this study. PETLD was performed using the foraminal (group A), intervertebral (group B), and suprapedicular (group C) routes in 32, 46, and 33 patients, respectively. Outcomes were evaluated using the visual analogue scale (VAS), Oswestry Disability Index (ODI), and MacNab criteria.

RESULTS

Seventy-one men and 40 were women (mean age 53.33 ± 14.12 years). The mean follow-up period was 6.44 ± 3.26 months. The preoperative VAS score decreased significantly (P < 0.01) in all 3 groups, but the postoperative VAS score was higher for the foraminal route than for the intervertebral (P = 0.001) and suprapedicular routes (P < 0.001). Excellent outcome grade according to MacNab criteria was less in foraminal route (18.7%) than in intervertebral (52.2%) and suprapedicular (56.7%) routes. ODI improved significantly (P < 0.01) in all 3 groups.

CONCLUSION

All 3 routes of PETLD resulted in good to excellent clinical results. Nevertheless, the postoperative VAS score was higher for the foraminal route than for the intervertebral and suprapedicular routes, probably not because of the surgery but because of the neurologic characteristics of the disk location. The surgeon should consider this problem to alleviate pain postoperatively and counsel to patient well before surgery.

Effects of release and decompression techniques on nerve roots through percutaneous transforaminal endoscopic discectomy on patients with central lumbar disc herniation

The clinical effects and safety of release and decompression techniques on nerve roots through percutaneous transforaminal endoscopic discectomy (PTED) while treating patients with central lumbar disc herniation (CLDH) were explored. Patient cases of lumbar and leg pain treated in Bethune International Peace Hospital from July 2013 to October 2015 were collected retrospectively. The patients in these cases received imaging examinations such as computed tomography and magnetic resonance imaging. Among these cases, 37 CLDH patients with no other complications were selected for this study. A total of 22 males and 15 females aged 28–54 years, with an average age of 36.8±1.5 years, were the subjects of the study. Their disease course was from 1 month to 3 years, with a median course time of 1.5 years. Visual analogue scale (VAS), Japanese Orthopaedic Association (JOA) scoring and the MacNab method were used to evaluate treatment effects. After permission from patients or their family members, release and decompression techniques of nerve roots were performed through PTED. All patients had successful surgery. Their average surgery time was 41.3 (25.5–57.1) min. A physician followed-up each patient from 0 to 18 months after surgery, with the average follow-up period of 12.1 months. VAS scoring of lower limbs was 7.95±0.82 before surgery and 2.28±0.35, 3 months after surgery. VAS scoring of lower limbs was 2.06±0.58, 1 year after surgery and 2.12±0.23 at the last follow-up appointment. JOA scoring was 12.6±0.72 before surgery and 20.4±1.08, 3 months after surgery. JOA scoring was 21.1±0.82 1 year after surgery and 21.2±0.36 at the last follow-up. Differences are of statistical significance (P<0.05). There were no complications for any of the cases. One patient did not improve after surgery, so a laminectomy and bone grafting internal fixation were performed. Two patients relapsed after surgery and received laminectomy and bone grafting internal fixation. The total percentage of excellent and good rates was 83.5%. In conclusion, release and decompression techniques on nerve roots using PTED while treating CLDH resulted in a safe, effective and less traumatic outcome with fewer complications and quicker pain relief than alternative treatments. Due to the results of this study, the use of these techniques in treating CLDH should be more widely considered.

A Modified Translaminar Osseous Channel-Assisted Percutaneous Endoscopic Lumbar Discectomy for Highly Migrated and Sequestrated Disc Herniations of the Upper Lumbar: Clinical Outcomes, Surgical Indications, and Technical Considerations

Objective is to describe a safe and effective percutaneous endoscopic approach for removal of highly migrated and sequestrated disc herniations of the upper lumbar spine and to report the results, surgical indications, and technical considerations of the new technique. Eleven patients who had highly migrated and sequestrated disc herniations in the upper lumbar were included in this study. A retrospective study was performed for all patients after translaminar osseous channel-assisted PELD was performed. Radiologic findings were investigated, and pre-and postoperative visual analog scale (VAS) assessments for back and leg pain and Oswestry disability index (ODI) evaluations were performed. Surgical outcomes were evaluated under modified MacNab criteria. All of the patients were followed for more than 1 year. The preoperative and postoperative radiologic findings revealed that the decompression of the herniated nucleus pulposus (HNP) was complete. After surgery, the mean VAS scores for back and leg pain immediately improved from 8.64 (range, 7–10) and 8.00 (range, 6–10) to 2.91 (range, 2–4) and 2.27 (range, 1–3), respectively. The mean preoperative ODI was 65.58 (range, 52.2–86), which decreased to 7.51 (range, 1.8–18) at the 12-month postoperative follow-up. The MacNab scores at the final follow-up included nine excellent, one good, and one fair. The modified translaminar osseous channel-assisted PELD could be a safe and effective option for the treatment of highly migrated and sequestrated disc herniations of the upper lumbar.

Clinical efficacy of lumbar interbody fusion using a channel system combined with ozone therapy for the treatment of central-type L3-L4 lumbar disc herniation

The clinical efficacy of minimally invasive lumbar interbody fusion via the intervertebral foramen combined with ozone (O₃) therapy for the treatment of L3-L4 central-type lumbar disc herniation was explored. We recruited patients with sciatica who attended our hospital between July 2013 and October 2015 and underwent lumbar X-ray (anteroposterior and lateral view), lumbar flexion-extension radiographs, computed tomography, and magnetic resonance imaging after admission. Seventy-four patients with central-type lumbar disc herniation but no other complications were randomly selected and divided into the observation and control groups. The observation group comprised 37 patients treated with lumbar fusion using a channel system combined with O₃ therapy, whereas the control group comprised 37 patients treated with lumbar fusion alone. The effects of the two therapies were evaluated using visual analog scale, Japanese Orthopaedic Association, and MacNab scores. There was no significant difference in scores between the two groups before surgery (P>0.05). The scores of the observation group after treatment were significantly lower than those before surgery and those of the control group (P<0.05). One patient in the observation group experienced no obvious improvement in symptoms after surgery, and two patients in the control group experienced postoperative recurrence; these three patients subsequently underwent laminectomy combined with planted bone fusion and internal fixation. There was no significant difference in total efficacy rates between the two groups (P>0.05). Lumbar fusion using a channel system combined with O₃ therapy for the treatment of L3-L4 central-type lumbar disc herniation is safe and effective. It has the advantages of reduced trauma, fewer complications, and rapid pain relief, and it promotes the recovery of lumbar function. Strict mastery of the surgical indications is key to the success of the procedure; however, it is worth expanding its use in the clinical setting.

Direct Tubular Lumbar Microdiscectomy for Far Lateral Disc Herniation: A Modified Approach

OBJECTIVE

The concept of minimally invasive tubular discectomy is based on precise placement of the retractor over the surgical target to minimize collateral tissue trauma. For far lateral disc herniation, the junction between the pars and the transverse process has generally been adopted as the target for facilitating early nerve root exposure; however, this may limit access to the disc space and increase the risks of iatrogenic neuralgia. An alternative approach to help address these issues involving docking the retractor caudally directly over the disc space with the aid of a microscope is here proposed. The purpose of this study was to evaluate the safety and efficacy of such an approach.

METHODS

Nineteen patients in whom the modified approach was performed over a 35-month period were identified. Direct access to the disc space was attained by directing the retractor against the lateral margin of the facet joint and following the inferior transverse process medially towards the foramen with minimal exposure of the nerve root. Clinical outcomes were assessed by the Oswestry Disability Index, visual analogue scale scores for leg and back pain, Short Form 36 physical functioning (SF36-PF) and bodily pain (SF36-BP) scores and sciatica bothersomeness and frequency indexes (SBI & SFI) and obtained from a prospective patient database. Follow-up data in the first 6 months were compared with preoperative baseline data.

RESULTS

All procedures were successfully completed with the modified approach. Contained disc herniation without sequestrated fragments was found in all but four cases. No perioperative complications or reoperation were recorded and no postoperative dysesthesia was noted. Clinically significant reductions in mean Oswestry Disability Index (32; 95% CI, 21-43) and visual analogue scale scores for leg pain (38 mm; 95% CI, 23-54 mm) and back pain (35 mm; 95% CI, 21-48 mm) scores were noted in the first 6 months. Significant improvements in SF36-PF (40; 95% CI, 30-51) and SF36-BP (35; 95% CI, 26-43), SBI (9; 95% CI, 6-11) and SFI (11; 95% CI, 8-13) were also recorded.

CONCLUSIONS

A modified direct tubular approach is safe and effective for treating far lateral lumbar disc herniation. Our early results suggest that this approach helps safeguard adequate decompression and reduce the risk of postoperative dysesthesia.

Consideration of proper operative route for interlaminar approach for percutaneous endoscopic lumbar discectomy

BACKGROUND

Percutaneous endoscopic lumbar discectomy (PELD) is one of the less invasive treatments of lumbar disc herniation (LDH), and has three different operative approaches. This study focused on the interlaminar approach (ILA) and investigated the appropriate operative route for this approach.

METHODS

ILA was performed in 41 patients with LDH. The width of the interlaminar space, LDH size, and positional relation between LDH and the corresponding nerve root were radiologically evaluated. Thirty-three LDHs were removed via the shoulder of the corresponding nerve root and eight were removed via the axilla of the corresponding nerve root and dural sac. Pre- and postoperative status were evaluated using the modified Japanese Orthopedic Association (mJOA) and numerical rating scale (NRS) scores.

RESULTS

The mean age was 41.5 years; there was single-level involvement, mostly at L5/S1 (33 cases). The mean recovery rate of mJOA score was 59.8% and mean pre- and postoperative NRS scores were 5.8 and 0.98, respectively. Relatively severe complications developed in three patients treated by ILA via the shoulder. There was persistent numbness in the corresponding nerve area, transient muscular weakness, and transient bladder and rectal disturbance, may be due to excessive compression of the nerve root and/or dural sac by the endoscopic sheath.

CONCLUSIONS

ILA can be used to treat LDH revealing an interlaminar space of ≥20 mm. The procedure is minimally invasive and effective; however, appropriate selection of an operative route is important to avoid operative complications. Particularly for large LDH, the operative route via the axilla should be considered.

Advantages and disadvantages of posterolateral approach for percutaneous endoscopic lumbar discectomy

BACKGROUND

Percutaneous endoscopic lumbar discectomy (PELD) is one of the less invasive treatments for lumbar disc herniation (LDH), and has 3 different operative approaches. This study focused on the posterolateral approach (PLA) and investigated the appropriate operative indication.

METHODS

PLA was performed in 29 patients with foraminal and extraforaminal LDH. The height and width of the foramen, LDH type, and positional relationship between LDH and the foramen were radiologically evaluated. Foraminoplasty was also performed in 12 cases including those combined with intra-canal LDH or osseous foraminal stenosis. Pre- and postoperative status was evaluated using Numerical Rating Scale (NRS) scores.

RESULTS

Patient mean age was 56.8 years; there was single-level involvement at L3/4 (13 cases) and at L4/5 (13 cases). The mean pre- and postoperative NRS scores were 6.1 and 1.8, respectively. Early recurrence developed in a patient who was found to have local scoliosis at the corresponding vertebral level.

CONCLUSIONS

PLA can be safely used to treat foraminal and extraforaminal LDH with foraminal height ≥13 mm and foraminal width ≥7 mm. The procedure is effective for preserving the facet joint; however, we should carefully consider the indications when local scoliosis and/or instability are present.

Patients with sciatica still experience pain and disability 5 years after surgery: A systematic review with meta-analysis of cohort studies

BACKGROUND AND OBJECTIVE

The clinical course of patients with sciatica is believed to be favourable, but there is conflicting evidence on the postoperative course of this condition. We aimed to investigate the clinical course of sciatica following surgery.

DATABASES AND DATA TREATMENT

An electronic search was conducted on MEDLINE, EMBASE and CINAHL from inception to April 2015. We screened for prospective cohort studies investigating pain or disability outcomes for patients with sciatica treated surgically. Fractional polynomial regression analysis was used to generate pooled means and 95% confidence intervals (CI) of pain and disability up to 5 years after surgery. Estimates of pain and disability (converted to a 0-100 scale) were plotted over time, from inception to last available follow-up time.

RESULTS

Forty records (39 cohort studies) were included with a total of 13,883 patients with sciatica. Before surgery, the pooled mean leg pain score was 75.2 (95% CI 68.1-82.4) which reduced to 15.3 (95% CI 8.5-22.1) at 3 months. Patients were never fully recovered in the long-term and pain increased to 21.0 (95% CI 12.5-29.5) at 5 years. The pooled mean disability score before surgery was 55.1 (95% CI 52.3-58.0) and this decreased to 15.5 (95% CI 13.3-17.6) at 3 months, and further reduced to 13.1 (95% CI 10.6-15.5) at 5 years.

CONCLUSIONS

Although surgery is followed by a rapid decrease in pain and disability by 3 months, patients still experience mild to moderate pain and disability 5 years after surgery. WHAT DOES THIS REVIEW ADD?: This review provides a quantitative summary of the postoperative course of patients with sciatica. Patients with sciatica experienced a rapid reduction in pain and disability in the first 3 months, but still had mild to moderate symptoms 5 years after surgery. Although no significant differences were found, microdiscectomy showed larger improvements compared to other surgical techniques.

Surgery related complications in percutaneous endoscopic lumbar discectomy under local anesthesia

The minimally invasive percutaneous endoscopic discectomy (PED) as the postero-lateral approach with the local anesthesia was started in the late 20th century. The procedure only requires 8 mm of skin incision; thus, it is the least invasive disc surgery presently. The surgery related complications were reviewed in the initial 100 cases from the single surgeon (K. S., first author). Two cases showed exiting nerve irritation, and complained of leg paresthetic pain for 6 to 12 weeks after the surgery (2.0%). The symptoms got better with medicines. One showed post-surgical epidural hematoma, and required surgical removal of the mass (1.0%). Two cases complained neck pain during surgery (2.0%). Surgeons would be aware of the specific complications for the postero-lateral approach of PED procedure.

More nerve root injuries occur with minimally invasive lumbar surgery, especially extreme lateral interbody fusion: A review

BACKGROUND

In the lumbar spine, do more nerve root injuries occur utilizing minimally invasive surgery (MIS) techniques versus open lumbar procedures? To answer this question, we compared the frequency of nerve root injuries for multiple open versus MIS operations including diskectomy, laminectomy with/without fusion addressing degenerative disc disease, stenosis, and/or degenerative spondylolisthesis.

METHODS

Several of Desai et al. large Spine Patient Outcomes Research Trial studies showed the frequency for nerve root injury following an open diskectomy ranged from 0.13% to 0.25%, for open laminectomy/stenosis with/without fusion it was 0%, and for open laminectomy/stenosis/degenerative spondylolisthesis with/without fusion it was 2%.

RESULTS

Alternatively, one study compared the incidence of root injuries utilizing MIS transforaminal lumbar interbody fusion (TLIF) versus posterior lumbar interbody fusion (PLIF) techniques; 7.8% of PLIF versus 2% of TLIF patients sustained root injuries. Furthermore, even higher frequencies of radiculitis and nerve root injuries occurred during anterior lumbar interbody fusions (ALIFs) versus extreme lateral interbody fusions (XLIFs). These high frequencies were far from acceptable; 15.8% following ALIF experienced postoperative radiculitis, while 23.8% undergoing XLIF sustained root/plexus deficits.

CONCLUSIONS

This review indicates that MIS (TLIF/PLIF/ALIF/XLIF) lumbar surgery resulted in a higher incidence of root injuries, radiculitis, or plexopathy versus open lumbar surgical techniques. Furthermore, even a cursory look at the XLIF data demonstrated the greater danger posed to neural tissue by this newest addition to the MIS lumbar surgical armamentariu. The latter should prompt us as spine surgeons to question why the XLIF procedure is still being offered to our patients?

Nefopam Reduces Dysesthesia after Percutaneous Endoscopic Lumbar Discectomy

Background

Neuropathic pain, including paresthesia/dysesthesia in the lower extremities, always develops and remains for at least one month, to variable degrees, after percutaneous endoscopic lumbar discectomy (PELD). The recently discovered dual analgesic mechanisms of action, similar to those of antidepressants and anticonvulsants, enable nefopam (NFP) to treat neuropathic pain. This study was performed to determine whether NFP might reduce the neuropathic pain component of postoperative pain.

Methods

Eighty patients, who underwent PELD due to herniated nucleus pulposus (HNP) at L4-L5, were randomly divided into two equal groups, one receiving NFP (with a mixture of morphine and ketorolac) and the other normal saline (NS) with the same mixture. The number of bolus infusions and the infused volume for 3 days were compared in both groups. The adverse reactions (ADRs) in both groups were recorded and compared. The neuropathic pain symptom inventory (NPSI) score was compared in both groups on postoperative days 1, 3, 7, 30, 60, and 90.

Results

The mean attempted number of bolus infusions, and effective infused bolus volume for 3 days was lower in the NFP group for 3 days. The most commonly reported ADRs were nausea, dizziness, and somnolence, in order of frequency in the NFP group. The median NPSI score, and all 5 median sub-scores in the NFP group, were significantly lower than that of the NS group until postoperative day 30.

Conclusions

NFP significantly reduced the neuropathic pain component, including paresthesia/dysesthesia until 1 month after PELD. The common ADRs were nausea, dizziness, somnolence, and ataxia.

Learning Curve of Percutaneous Endoscopic Lumbar Discectomy Based on the Period (Early vs. Late) and Technique (in-and-out vs. in-and-out-and-in): A Retrospective Comparative Study

Objective

To report the learning curve of percutaneous endoscopic lumbar discectomy (PELD) for a surgeon who had not been previously exposed to this procedure based on the period and detailed technique with a retrospective matched comparative design.

Methods

Of 213 patients with lumbar disc herniation encountered during the reference period, 35 patients who were followed up for 1 year after PELD were enrolled in this study. The patients were categorized by the period and technique of operation : group A, the first 15 cases, who underwent by the 'in-and-out' technique; group B, the next 20 cases, who underwent by the 'in-and-out-and-in' technique. The operation time, failure rate, blood loss, complication rate, re-herniation rate, the Visual Analogue Scale (VAS) for back and leg were checked. The alteration of dural sac cross-sectional area (DSCSA) between the preoperative and the postoperative MRI was checked.

Results

Operative time was rapidly reduced in the early phase, and then tapered to a steady state for the 35 cases receiving the PELD. After surgery, VAS scores for the back and leg were decreased significantly in both groups. Complications occurred in 2 patients in group A and 2 patients in group B. Between the two groups, there were significant differences in operative time, improvement of leg VAS, and expansion of DSCSA.

Conclusion

PELD learning curve seems to be acceptable with sufficient preparation. However, because of their high tendency to delayed operation time, operation failure, and re-herniation, caution should be exercised at the early phase of the procedure.

Lumbar Endoscopic Microdiscectomy: Where Are We Now? An Updated Literature Review Focused on Clinical Outcome, Complications, and Rate of Recurrence

Endoscopic disc surgery (EDS) for lumbar spine disc herniation is a well-known but developing field, which is increasingly spreading in the last few years. Rate of recurrence/residual, complications, and outcomes, in comparison with standard microdiscectomy (MD), is still debated and need further data. We performed an extensive review based on the last 6 years of surgical series, systematic reviews, and meta-analyses reported in international, English-written literature. Articles regarding patients treated through endoscopic transforaminal or interlaminar approaches for microdiscectomy (MD) were included in the present review. Papers focused on endoscopic surgery for other spinal diseases were not included. From July 2009 to July 2015, we identified 51 surgical series, 5 systematic reviews, and one meta-analysis reported. In lumbar EDS, rate of complications, length of hospital staying, return to daily activities, and overall patients' satisfaction seem comparable to standard MD. Rate of recurrence/residual seems higher in EDS, although data are nonhomogeneous among different series. Surgical indication and experience of the performing surgeon are crucial factors affecting the outcome. There is growing but still weak evidence that lumbar EDS is a valid and safe alternative to standard open microdiscectomy. Statistically reliable data obtained from randomized controlled trials (better if multicentric) are desirable to further confirm these results.

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

Surgical management of back and leg pain is evolving and changing due to a better understanding of the patho-anatomy well correlated with its pathophysiology. Pain is better understood with in vivo visualization and probing of the pain generators using an endoscopic access rather than just relying on symptoms diagram and image correlation. This has resulted in a shared decision making involving patient and surgeon, focused on a broader spectrum of surgical as well as non-surgical treatments, and not just masking the pain generator. It has moved away from decisions based on diagnostic images alone, that, while noting the image alterations, cannot explain the pain experienced by each individual as images do not always show variations in nerve supply and patho-anatomy. The ability to isolate and visualize "pain" generators in the foramen and treating persistent pain by visualizing inflammation and compression of nerves, serves as the basis for transforaminal endoscopic (TFE) surgery. This has also resulted in better pre surgical planning with more specific and defined goals in mind. The "Inside out" philosophy of TFE surgery is safe and precise. It provides basic access to the disc and foramen to cover a large spectrum of painful pathologies.

Exiting root injury in transforaminal endoscopic discectomy: preoperative image considerations for safety

PURPOSE

To evaluate the clinical and radiological risk factors for exiting root injuries during transforaminal endoscopic discectomy.

METHODS

We retrospectively examined cohort data from 233 patients who underwent percutaneous endoscopic lumbar discectomy for lumbar disc herniation between January 1st, 2010 and December 31st, 2011. We divided the patients into the two groups: those who presented a postoperative exiting root injury, such as postoperative dysesthesia or motor weakness (Group A, n = 20), and those who did not suffer from a root injury (Group B, n = 213). We examined the clinical and radiological factors relating exiting root injuries. We measured the active working zone with the exiting root to the upper facet distance (Distance A), the exiting root to disc surface distance at the lower facet line (Distance B) and the exiting root to the lower facet distance (Distance C) in magnetic resonance imaging (MRI).

RESULTS

Group A exhibited a shorter Distance C (6.4 ± 1.5 versus 4.4 ± 0.8 mm, p < 0.001) and a longer operation time (67.9 ± 21.8 versus 80.3 ± 23.7 min, p = 0.017) relative to Group B. The complication rate decreased by 23% per each 1-mm increase in Distance C (p = 0.000). In addition, the complication rate increased 1.027-fold per each 1-min increase in the operation time (p = 0.027).

CONCLUSION

We recommend measuring the distance from the exiting root to the facet at the lower disc level according to a preoperative MRI scan. If the distance is narrow, an alternative surgical method, such as microdiscectomy or conventional open discectomy, should be considered.

Transforaminal percutaneous endoscopic lumbar discectomy: technical tips to prevent complications

Transforaminal percutaneous endoscopic lumbar discectomy is regarded as an effective alternative to open discectomy. Remarkable technical evolution now enables selective endoscopic removal of an epidurally extruded disc fragment. As a result, the surgical indications for this technique are becoming broader. However, as the use of endoscopic techniques increases in spinal procedures, related complications emerge as important problems. These include postoperative dysesthesia, dural tears, hematoma, infection and visceral injury. There are several technical guidelines to increase the effectiveness of endoscopic techniques and prevent complications. Initial landing should be as close to the target as possible. Complete herniotomy after thorough release of annular anchorage is a key to success. The definitive end point of the procedure is free mobilization of neural tissues, not direct exposure of neural tissues.