Percutaneous endoscopic discectomy for far lateral lumbar disc herniations: prospective study and outcome of 66 patients

Surgical Treatment of Far Lateral Lumbar Disc Herniation: Outcomes of the Safe and Simple Midline Approach

Objective

Surgery for far lateral lumbar disc herniation (FLLDH) hernias is different than surgery for median and paramedian disc hernias. Our study offers a minimally invasive surgical technic for far lateral disc herniations.

Methods

The results of the midline surgical approach in 18 patients diagnosed with FLLDH were evaluated retrospectively.

Results

A total of 18 patients (7 females, 11 males), with a mean age of 57.9±9.4 years (range: 35-71 years), were included in the analyses. Three patients (16.7%) had lesions at the left L3-L4 level, six patients (33.3%) on the left L4-L5 level, five patients (27.8%) on the right L3-L4 level, and four patients (22.2%) on the right L4-L5 level. All patients had low back and leg pain. These complaints completely regressed after surgery.

Conclusion

This study presents a review of a consecutive series of patients who underwent minimally invasive surgery for FLLDH using a midline approach.

Clinical and Radiological Comparisons of Percutaneous Low-Power Laser Discectomy and Low-Temperature Plasma Radiofrequency Ablation for Cervical Radiculopathy: A Prospective, Multicenter, Cohort Study

Background

Minimally invasive techniques, such as percutaneous low-power laser discectomy (PLLD) and low-temperature plasma radiofrequency ablation (coblation) can be applied to treat degenerative cervical radiculopathy. However, less evidence supports the superiority of distinct minimally-invasive therapy. Our study aimed to evaluate the clinical and radiological characteristics of the PLLD and coblation for cervical radiculopathy.

Methods

This was a prospective, multicenter, cohort study (ChiCTR-ONC-17010356). The modified Macnab criteria was performed to assess the clinical improvement pre- and post-surgery. To evaluate the radiological effect, the Pfirrmann grading system and disk herniation index were applied with MRI.

Results

In this study, 28 patients were enrolled in the coblation group and 30 patients in the PLLD group. The mean good-excellent rate at 3-month follow-up was 82.1% for PLLD group, and 66.7% for coblation group, respectively (p = 0.179). The PLLD group achieved higher good-excellent rate 6 and 12 months after discharge (92.9 vs. 70.0%, p = 0.026). Radiological data revealed that PLLD but not coblation treatment achieved significant reduction of disk herniation index (p < 0.0001). Coblation treatment did not change the Pfirrmann grades of cervical radiculopathy patients (n = 18), and 7 out of 17 (41.2%) patients achieved improvement after PLLD therapy. None obvious adverse event was observed in this study.

Conclusion

Both PLLD and coblation are effective and safe option for patients with cervical radiculopathy. Better long-term clinical outcomes may be potentially associated with the improvement of disk degeneration after PLLD treatment.

The diagnostic pitfalls of lumbar disc herniation---- malignant sciatic nerve tumour: two case reports and literature review

Background

Sciatica pain is a typical symptom of lumbar disc herniation (LDH), but some neurogenic and malignant tumours surrounding the sciatic nerve can also cause similar symptoms. These tumours are often misdiagnosed or even mistreated as LDH in clinical practice.

Case presentation

In our clinical practice, we found two patients with malignant tumours who were misdiagnosed with LDH. One patient complained of pain and numbness in the right lower limb. The primary diagnosis was LDH, and the patient underwent posterior lumbar interbody fusion surgery. After the operation, the symptoms were not alleviated. Then, diffuse large B-cell lymphoma involving the soft tissue and the sciatic nerve was identified. Another patient who manifested with radiating pain in the right lower limb was diagnosed with LDH at Chengde Central Hospital. He received regular conservative treatment for approximately 6 months, but his symptoms were not relieved, and then he was referred to our hospital. A malignant peripheral nerve sheath tumour (MPNST) of the sciatic nerve was diagnosed, and he received cisplatin (DDP) chemohyperthermia.

Conclusions

Descriptions of tumour lesions involving the sciatic nerve and misdiagnosed as LDH in the literature are rare. In the reported literature, 7 patients were misdiagnosed with LDH, and all patients presented with sciatica. Among them, 4 patients only received surgical treatment, 1 patient only underwent neurolysis, and 2 patients received both surgical and chemotherapy treatment. Their low incidence and similar clinical manifestations to LDH make malignant tumours involving the sciatic nerve easy to misdiagnose. When the clinical symptoms and signs are inconsistent with the imaging findings, we need to be aware of non-discogenic sciatica, including tumours involving the sciatic nerve. Furthermore, tumours that grow near the exit of the sciatic notch may be misdiagnosed because of their deeper location and because they are covered with gluteal muscles. Sometimes sciatica caused by sciatic nerve tumours is only distal, without any radicular distribution. This pain is more severe than that caused by LDH, and this pain is not related to the position of the lumbar spine. Thus, it is beneficial to perform a detailed physical examination of the sciatic nerve to avoid this kind of misdiagnosis.

A matched comparison of outcomes between percutaneous endoscopic lumbar discectomy and open lumbar microdiscectomy for the treatment of lumbar disc herniation: a 2-year retrospective cohort study

BACKGROUND CONTEXT

Although open lumbar microdiscectomy (OLMD) is considered to be the gold standard method for discectomy, recent progress in endoscopic spinal surgery has increased the popularity of percutaneous endoscopic lumbar discectomy (PELD) for this indication. However, one of the main drawbacks of PELD is incomplete decompression, especially at the start of the surgeon's learning curve. The functional outcomes of PELD and OLMD in patients matched for age, hernia level, and hernia location have not previously been compared.

PURPOSE

To compare OLMD with PELD in terms of the clinical outcome and the time to recovery.

STUDY DESIGN

Retrospective, matched cohort study.

PATIENT SAMPLE

Data of all patients who underwent elective spinal surgery between January 2015 and June 2017 were extracted from the local database.

OUTCOME MEASURES

Clinical outcomes were assessed using a 0-to-10 visual analogue scale (VAS) for lower back pain (LBP) and leg pain were scored before surgery and at postoperative day 1 and at each follow-up visit (3, 12, and 24 months), the Oswestry Disability Index (ODI: 0%-100%), the length of hospital stay, time to resumption of work, recurrence of Lumbar disc herniation, procedure failures, and complications.

METHODS

The participants were matched for age, disc level, and location of the herniated disk (central and paracentral vs. far-lateral). The participants' mean±standard deviation age was 47.09±12.55 (range: 28-70). We compared the various clinical outcomes between the two groups to identify which procedure had better immediate and long-term functional outcomes. The differences in mortality and occurrence of postoperative complications were also compared in patients with PELD versus controls.

RESULTS

Fifty-eight patients were enrolled (29 with PELD and 29 with OLMD). Both groups reported significant reductions in LBP and leg pain (p<0.01) postoperatively and an improvement in the ODI at 24 months postsurgery. The intergroup difference in the VAS for LBP at 1 day and 3 months was statistically significant (1.48 vs. 3.5, and 1.62 vs. 2.72, respectively; p=0.01 and 0.026, respectively) but the intergroup difference in the ODI was not. The mean length of hospital stay and the time to resumption of work were significantly shorter in the PELD group than in the OLMD group (2.55 vs. 3.21 days, and 4.45 vs. 6.62 weeks, respectively; p=0.037 and 0.01, respectively. There were no significant intergroup differences in terms of complications, recurrence, or procedure failures.

CONCLUSIONS

Both PELD and OLMD can provide equivalent, satisfactory outcomes. However, PELD demonstrated several potential advantages, including more rapid recovery and lower LBP early on. Further large-scale, randomized studies with long-term follow-up are now warranted.

Artificial Intelligence Comparison of the Radiologist Report With Endoscopic Predictors of Successful Transforaminal Decompression for Painful Conditions of the Lumber Spine: Application of Deep Learning Algorithm Interpretation of Routine Lumbar Magnetic Resonance Imaging Scan

BACKGROUND

Identifying pain generators in multilevel lumbar degenerative disc disease is not trivial but is crucial for lasting symptom relief with the targeted endoscopic spinal decompression surgery. Artificial intelligence (AI) applications of deep learning neural networks to the analysis of routine lumbar MRI scans could help the primary care and endoscopic specialist physician to compare the radiologist's report with a review of endoscopic clinical outcomes.

OBJECTIVE

To analyze and compare the probability of predicting successful outcome with lumbar spinal endoscopy by using the radiologist's MRI grading and interpretation of the radiologic image with a novel AI deep learning neural network (Multus Radbot™) as independent prognosticators.

METHODS

The location and severity of foraminal stenosis were analyzed using comparative ordinal grading by the radiologist, and a contiguous grading by the AI network in patients suffering from lateral recess and foraminal stenosis due to lumbar herniated disc. The compressive pathology definitions were extracted from the radiologist lumbar MRI reports from 65 patients with a total of 383 levels for the central canal - (0) no disc bulge/protrusion/canal stenosis, (1) disc bulge without canal stenosis, (2) disc bulge resulting in canal stenosis, and (3) disc herniation/protrusion/extrusion resulting in canal stenosis. Both neural foramina were assessed with either - (0) neural foraminal stenosis absent, or (1) neural foramina are stenosis present. Reporting criteria for the pathologies at each disc level and, when available, the grading of severity were extracted and assigned into two categories: "Normal," and "Stenosis." Clinical outcomes were graded using dichotomized modified Macnab criteria considering Excellent and Good results as "Improved," and Fair and Poor outcomes as "Not Improved." Binary logistic regression analysis was used to predict the probability of the AI- and radiologist grading of stenosis at the 88 foraminal decompression sites to result in "Improved" outcomes.

RESULTS

The average age of the 65 patients was 62.7 +/- 12.7 years. They consisted of 51 (54.3%) males and 43 (45.7%) females. At an average final follow-up of 57.4 +/- 12.57, Macnab outcome analysis showed that 86.4% of the 88 foraminal decompressions resulted in Excellent and Good (Improved) clinical outcomes. The stenosis grading by the radiologist showed an average severity score of 4.71 +/- 2.626, and the average AI severity grading was 5.65 +/- 3.73. Logit regression probability analysis of the two independent prognosticators showed that both the grading by the radiologist (86.2%; odds ratio 1.264) and the AI grading (86.4%; odds ratio 1.267) were nearly equally predictive of a successful outcome with the endoscopic decompression.

CONCLUSIONS

Deep learning algorithms are capable of identifying lumbar foraminal compression due to herniated disc. The treatment outcome was correlated to the decompression of the directly visualized corresponding pathology during the lumbar endoscopy. This research should be extended to other validated pain generators in the lumbar spine.

LEVEL OF EVIDENCE

3.

CLINICAL RELEVANCE

Validity, clinical teaching, evaluation study.

AOSpine Consensus Paper on Nomenclature for Working-Channel Endoscopic Spinal Procedures

STUDY DESIGN

International consensus paper on a unified nomenclature for full-endoscopic spine surgery.

OBJECTIVES

Minimally invasive endoscopic spinal procedures have undergone rapid development during the past decade. Evolution of working-channel endoscopes and surgical instruments as well as innovation in surgical techniques have expanded the types of spinal pathology that can be addressed. However, there is in the literature a heterogeneous nomenclature defining approach corridors and procedures, and this lack of common language has hampered communication between endoscopic spine surgeons, patients, hospitals, and insurance providers.

METHODS

The current report summarizes the nomenclature reported for working-channel endoscopic procedures that address cervical, thoracic, and lumbar spinal pathology.

RESULTS

We propose a uniform system that defines the working-channel endoscope (full-endoscopic), approach corridor (anterior, posterior, interlaminar, transforaminal), spinal segment (cervical, thoracic, lumbar), and procedure performed (eg, discectomy, foraminotomy). We suggest the following nomenclature for the most common full-endoscopic procedures: posterior endoscopic cervical foraminotomy (PECF), transforaminal endoscopic thoracic discectomy (TETD), transforaminal endoscopic lumbar discectomy (TELD), transforaminal lumbar foraminotomy (TELF), interlaminar endoscopic lumbar discectomy (IELD), interlaminar endoscopic lateral recess decompression (IE-LRD), and lumbar endoscopic unilateral laminotomy for bilateral decompression (LE-ULBD).

CONCLUSIONS

We believe that it is critical to delineate a consensus nomenclature to facilitate uniformity of working-channel endoscopic procedures within academic scholarship. This will hopefully facilitate development, standardization of procedures, teaching, and widespread acceptance of full-endoscopic spinal procedures.

Kambin's triangle: definition and new classification schema

Kambin's triangle is an anatomical corridor used to access critical structures in a variety of spinal procedures. It is considered a safe space because it is devoid of vascular and neural structures of importance. Nonetheless, there is currently significant variation in the literature regarding the exact dimensions and anatomical borders of Kambin's triangle. This confusion was originally caused by leaving the superior articular process (SAP) unassigned in the description of the working triangle, despite Kambin identifying that structure in his original report. The SAP is the most relevant structure to consider when accessing the transforaminal corridor. Leaving the SAP unassigned has led to an open-handed application of the term "Kambin's triangle." That single eponym currently has two potential meanings, one meaning for endoscopic surgeons working through a corridor in the intact spine and a second meaning for surgeons accessing the disc space after a complete or partial facetectomy. Nevertheless, an anatomical corridor should have one consistent definition to clearly communicate techniques and use of instrumentation performed through that space. As such, the authors propose a new surgically relevant classification of this corridor. Assigning the SAP a border requires adding another dimension to the triangle, thereby transforming it into a prism. The term "Kambin's prism" indicates the assignment of a border to all relevant anatomical structures, allowing for a uniform definition of the 3D space. From there, the classification scheme considers the expansion of the corridor and the extent of bone removal, with a particular focus on the SAP.

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

Background

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

Methods

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

Results

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

Conclusions

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

Microendoscopic discectomy (MED) for lumbar disc herniation: comparison of learning curve of the surgery and outcome with other established case studies

Background

To compare the results of a series of microendoscopic discectomies done at a government medical college in South India, with other published series and to analyze the learning curve for the procedure.

Methods

Microendoscopic discectomy (MED) was performed in 40 patients. The cases were in the age group between 20-50 years (mean age, 32.3 years). The period of study was 3 years. The most common level operated was L5-S1 (27 cases) followed by L4-L5 (12 cases). Double level disc herniation was observed in 1 patient, at L4-L5 and L5-S1. Patients with bilateral involvement and lumbar stenosis were excluded from the study. Diagnosis was based on clinical neurological examination, X-ray, CT and MRI. The MED was performed, following Destandau's procedure using Storz endoscopic microdiscectomy system. All patients were followed up regularly on 10^th postoperative day, 1 month, 3 months and 1 year. Mean follow up of all patients were 14.1 months. The learning curve for the procedure was also analyzed.

Results

In our case series comprising of 40 cases, it was observed that as compared to other established studies, the mean operative duration, intraoperative blood loss, mean hospital stay and complication rate was largely reduced, with good experience and training. The outcome based upon modified Macnab criteria, showed that in maximum number of patients had excellent outcome and only 3 out of the 40 cases had poor outcome. Moreover, since the procedure was technically demanding, it took initial 20 cases to complete our learning curve and in the next 20 cases it was observed that we had improved our technique, operating time, blood loss, and outcome.

Conclusions

MED in properly trained hands is an excellent technique that could replace the conventional open surgery, in the management of lumbar disc disease if the learning curve could be overcome.

Case presentation and short perspective on management of foraminal/far lateral discs and stenosis

Background

The management of lumbar foraminal/far lateral discs (FOR/FLD) with stenosis remains controversial. Operative choices should be based on each patient's preoperative dynamic X-ray findings, magnetic resonance (MR), and computed tomography (CT) studies. Here we reviewed several options for decompression alone vs. decompression with fusion.

Methods

Safe excision of FOR/FLD with stenosis should begin at the level above the disc herniation, as identification of the superior, foraminally, and far laterally exiting nerve root is critical. Performing an undercutting laminectomy and utilizing an operating microscope usually preserves the facet joints, and in many cases, avoids the need for fusion. Other decompressive techniques include; the intertransverse (ITT), and Wiltse approaches. Fusions following complete unilateral full facetectomy may be; noninstrumented (e.g., older, osteoporotic patients) vs. instrumented (e.g., posterolateral fusion or occasionally transforaminal lumbar interbody fusion). Here we present a patient with L2-L5 stenosis, and a left L3-L4 FOR/FLD, and multiple synovial cysts who was successfully managed with an l2-L5 laminecotmy, left L34 FOR/FLD diksectomy without fusion.

Results

Postoperatively, the patient was neurologically intact, and stability was maintained. Adjunctive measures for FOR/FLD diksectomy should include; intraoperative monitoring, use of the operating microscope, and an intraoperative film with a radiopaque marker in the correct disc space to confirm the correct level of diskectomy.

Conclusions

There are multiple approaches to the excision of FOR/FLD with stenosis. These include; decompression alone vs. decompression with non-instrumented vs. instrumented fusion. Surgical choices must be based on individual patient's X-ray, MR, and CT findings. The aim should be to maximize the safety of disc excision with decompression of stenosis, and to preserve stability, reducing the need for fusion, while minimizing morbidity.

Extraforaminal microscopic assisted percutaneous nucleotomy for foraminal and extraforaminal lumbar disc herniations

BACKGROUND

Foraminal and extraforaminal lumbar disc herniations are uncommon. The main presentation is radicular pain related to the exiting nerve root at the affected level. Different approaches for surgical intervention have been described.

PURPOSE

This study aimed to evaluate the clinical outcome, complications recurrence, and reoperation rate of extraforaminal microscopic-assisted percutaneous nucleotomy, with literature review focusing on complications and recurrence rate.

STUDY DESIGN

This is a prospective cohort study done in a high-flow spine center in Germany.

PATIENT SAMPLE

Between October 2012 and October 2015, 76 patients (35 women and 41 men) with foraminal or extraforaminal lumbar disc prolapse were operated on.

OUTCOME MEASURES

The following were the outcome measures: (1) self-report measures: Visual Analogue Scale (VAS) for leg pain and back pain; (2) physiological measures: standing plain X-rays (anterioposterior, lateral, and dynamic views); and (3) functional measures: Oswestry Disability Index (ODI) (validated German version) and Odom's criteria.

METHODS

All patients were operated upon with trans-tubular extraforaminal microscopic-assisted percutaneous nucleotomy (EF-MAPN) technique. Preoperative clinical and neurologic evaluations were done. The mean follow-up period was 38 months (range 12-54). The study has not received funding for research from any organization. All authors do not have any conflict of interest.

RESULTS

The mean age was 54 years. The most commonly affected level was L4/L5 (34 patients). The mean preoperative VAS for leg pain was 7.6 (3-10), which improved to 1.4 (0-4) postoperatively. The average operative time was 57.5 minutes. There were no intraoperative complications. One patient had temporary postoperative quadriceps weakness (L4 radiculopathy) that was completely improved at 3 months' follow-up. Another patient had deep venous thrombosis after discharge. Two patients had recurrences that necessitated another operation within the first 6 months postoperatively. Both were followed up for 1 year without a second recurrence.

CONCLUSION

Trans-tubular percutaneous extraforaminal microscopic-assisted nucleotomy is effective for foraminal and extraforaminal disc herniations. It is a muscle-splitting minimally invasive approach with minimal morbidity. Complications, recurrence, and reoperation rate are not different compared with microsurgical open or endoscopic techniques.

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.

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.

State of the art: Transforaminal approach for percutaneous endoscopic lumbar discectomy under local anesthesia

Minimally invasive percutaneous endoscopic discectomy (PED) with a transforaminal approach under local anesthesia was started in the late 20th century. As the procedure requires a skin incision of only 8 mm, it is the least invasive disc surgery procedure at present, and owing to advances in instruments and optics, the use of this technique has gradually spread. In Japan, Dr. Dezawa from Teikyo University Mizonokuchi Hospital introduced this technique in 2003. Thanks to his efforts, the number of surgeons who can perform PED has increased, although the number of active PED surgeons is still only around 20. The first author (K.S.) started PED in 2010. In this review article, we explain the state-of-the-art PED transforaminal technique for minimally invasive disc surgery and present three successful cases.

The role of transforaminal percutaneous endoscopic discectomy in lumbar disc herniations

OBJECTIVES

To study 1)the efficacy of transforaminal percutaneous endoscopic lumbar discectomy in lumbar disc herniations.2) limitations and advantages of the surgical procedure. 3)morbidity and complications associated with the procedure.

MATERIALS AND METHODS

This study was carried out on 120 patients who had single level herniated disc Pre-operative assessment of VAS and MSS scoring systems were documented one day prior to surgery. Post operative results were determined by MacNab criteria and by modified Suezawa and Schreiber clinical scoring system (MSS score).

RESULTS

Maximum patients were in the age group of 31 to 40 years and 83.43% of the patients were males. 80% patients had lumbar disc herniation at L4-L5 level, The mean operative time of endoscopic discectomy was 52.28 minutes and the mean hospital stay was 2.1days.8 cases of L5-S I were abandoned due to high iliac bone and hence their disc could not be accessed. Out of 112 patients who underwent operation, 2 patients developed discitis and 1 was found to have dysesthesia. Also recurrent prolapsed intervertebral disc was seen in 6 cases The mean preoperative and 6 months follow-up VAS score was 8.4 and 1.89 respectively. Mean preoperative and 6 months follow-up Modified Suezawa And Schreiber Clinical Scoring System(MSS Score) was 3.47 and 7.92 respectively. MSS score showed excellent and good outcome in 82.12% patients and Modified Macnab Criteria showed excellent and good outcome in 89.3% patients at 6months follow-up.

CONCLUSION

TPELD can be a reasonable alternative to conventional microscopic discectomy for the treatment of patients with LDH. We also conclude that TPELD is not an effective procedure for L5-S 1 disc and an open procedure should be opted for better outcomes.

Treatment of lumbar disc herniation with radiculopathy. Clinical practice guidelines endorsed by The Polish Society of Spinal Surgery

INTRODUCTION

Herniated lumbar disc (HLD) is arguably the most common spinal disorder requiring surgical intervention. Although the term is fairly straightforward, the exact pathology and thus the clinical picture and natural history may vary. Therefore, it is immensely difficult to formulate universal guidelines for surgical treatment.

AIM

The aim of this paper is to organize the terminology and clear the inconsistencies in phraseology, review treatment options and gather available published evidence to address the clinical questions to create a set of clinical guidelines in relevant to the topic.

METHODS AND RESULTS

Twelve queries, addressing optimal surgical treatment of the HLD have been formulated. The results, based on the literature review are described in the present work. The final product of the analysis was a set of guidelines for the surgical treatment of symptomatic HLD. Categorized into four tiers based on the level of evidence (I-III and X), they have been designed to assist in the selection of optimal, effective treatment leading to the successful outcome.

CONCLUSIONS

The evidence based medicine (EBM) is becoming ever more popular among spinal surgeons. Unfortunately this is not always feasible. Lack of uniform guidelines and numerous conflicts of interest introduce flaws in the decision making process. The key role of experts and professional societies is to provide high value recommendation based on the most current literature. Present work contains a set of guidelines for the surgical treatment of HLD officially endorsed by the Polish Spine Surgery Society.

Endoscopic lumbar discectomy under local anesthesia may be an alternative to microdiscectomy: A single centre's experience using the far lateral approach

OBJECTIVES

Since the turn of the century, minimally invasive surgery has become increasingly widespread. Discectomy surgery has evolved from wide open to microscopic and now endoscopic. This study aims to demonstrate that transforaminal endoscopic discectomy is an alternative and safe approach for degenerative disk surgery.

PATIENTS AND METHODS

Two year retrospective assessments of patients who underwent transforaminal endoscopic discectomy at a tertiary neurosurgical center in the United Kingdom by a single surgeon. Under strict confidentiality, data was collected from online patient data and PACS systems. Patient feedback was achieved using phone call follow up and clinic appointments. Standard statistical analysis was performed.

RESULTS

201 patients had endoscopic discectomy and the mean age was 41 years. Male:female ratio was 1.3:1.0. Mean time of onset of symptoms was 5.5 months and the most common level was L4/5 (53%). All endoscopic discectomies were performed under local anesthesia. Theater time was on average 110 min. 10 patients were lost to follow up. 95% of patients were discharged within 7h post operatively. Visual acuity score of the pain dropped from an average of 7/10 pre-operatively to 0-1/10 in 95% of patients two weeks post operatively. 87% patients went back to their normal daily activities within two weeks. There were no cases of CSF leak, hematoma formation or wound infection. 1% of patients developed a nerve root injury. 6% of patients had recurrent herniation and require microdiscectomy.

CONCLUSION

Endoscopic discectomy can be an alternative approach to microdiscectomy. While it can take more expertise to perform endoscopic discectomy, our data shows that the far lateral endoscopic discectomy using the TESSYS technique has comparable outcomes to microdiscectomy.

Risk factors for failure of single-level percutaneous endoscopic lumbar discectomy

OBJECT

Few studies have addressed surgical failures and complications following percutaneous endoscopic lumbar discectomy (PELD), and no previous study has investigated the risk factors that lead to surgical failure. The authors report their experience using PELD for single-level lumbar disc herniation (LDH) to provide insights into the rates of surgical failure and identify potential risk factors that lead to this complication.

METHODS

The authors retrospectively reviewed the medical records of 350 patients who underwent PELD for single-level LDH and identified 36 patients (10.3%) who underwent reoperation due to the failure of PELD.

RESULTS

Patients’ mean visual analog scale of pain scores and Oswestry Disability Index scores improved significantly from 6.6 ± 2.1 and 51.6 ± 19.4 preoperatively to 1.9 ± 1.4 and 28.3 ± 12.0, respectively, at 1 month postoperatively and 1.2 ± 1.1 and 9.3 ± 7.8, respectively, at 1 year postoperatively. The frequencies with which patients took analgesic medications significantly decreased from 74.6% preoperatively to 19.7% at 1 month postoperatively and 10.0% at 1 year postoperatively. Relatively older patients (p = 0.005) and those ≥ 60 years old (p = 0.001) experienced larger numbers of failures compared to younger patients. An analysis of potentially contributing comorbid conditions indicated that significantly more patients with diabetes were present in the PELD failure group (p = 0.017). As surgeons gained familiarity with the procedure, outcomes improved. The failure rate during the authors’ early use of the PELD technique (Cases 1–70) was 17.1%; the failure rate then fell to 5.7% (p = 0.034) (Cases 141–210) before finally stabilizing at 10.0% (Cases 211–280 and Cases 281–350).

CONCLUSIONS

The surgical failure rate following PELD for LDH was 10.3%. Older patients, elderly patients (age ≥ 60 years), and patients with diabetes were at increased risk of surgical failure of PELD, particularly in the early years of the procedure’s use.

Clinical outcomes and efficacy of transforaminal lumbar endoscopic discectomy

Background:

Transforaminal lumbar endoscopic discectomy (TLED) is a minimally invasive procedure for removing lumbar disc herniations. This technique was initially reserved for herniations in the foraminal or extraforaminal region. This study concentrated on our experience regarding the outcomes and efficacy of TLED.

Materials and Methods:

A total of 105 patients were included in the study. The patients were retrospectively evaluated for demographic features, lesion levels, numbers of affected levels, visual analog scores (VASs), Oswestry disability questionnaire scale scores and MacNab pain relief scores.

Results:

A total of 48 female and 57 male patients aged between 25 and 64 years (mean: 41.8 years) underwent TLED procedures. The majority (83%) of the cases were operated on at the levels of L4-5 and L5-S1. Five patients had herniations at two levels. There were significant decreases between the preoperative VAS scores collected postoperatively at 6 months (2.3) and those collected after 1-year (2.5). Two patients were referred for microdiscectomy after TLED due to unsatisfactory pain relief on the 1^st postoperative day. The overall success rate with respect to pain relief was 90.4% (95/105). Seven patients with previous histories of open discectomy at the same level reported fair pain relief after TLED.

Conclusions:

Transforaminal lumbar endoscopic discectomy is a safe and effective alternative to microdiscectomy that is associated with minor tissue trauma. Herniations that involved single levels and foraminal/extraforaminal localizations were associated with better responses to TLED.

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.

Transforaminal percutaneous endoscopic surgery for far lateral lumbar intervertebral disk herniation

Far lateral lumbar intervertebral disk herniation (FLLIDH) most commonly occurs far lateral to the intervertebral facet at L3-L4 and L4-L5 and accounts for 3.8% of all lumbar disk herniations. Traditional surgery for FLLIDH involves massive surgical trauma, damage to the spinal structure, and instability of the lumbar spine. The goals of this study were to perform a systematic review of the literature and investigate the clinical outcomes of transforaminal percutaneous endoscopic surgery in the treatment of FLLIDH. Between October 2010 and May 2012, fifteen patients diagnosed with FLLIDH underwent transforaminal percutaneous endoscopic surgery at the authors' institution to remove the herniated disk and release the nerve root. Pain was measured pre- and postoperatively with a visual analog pain scale (VAS), and postoperative outcomes were evaluated using MacNab's criteria. A PubMed database search was conducted for the systematic review. Median operative time was 100 minutes (range, 80-140 minutes). Median volume of intraoperative blood loss was 20 mL (range, 10-50 mL). Patients were followed postoperatively for a median of 6 months (range, 1-12 months). MacNab's criteria rated 12 (80.0%) surgical outcomes as excellent, 2 (13.3%) as good, and 1 (6.7%) as fair. The systematic review included 14 studies. Transforaminal percutaneous endoscopic surgery appears to be a safe and effective minimally invasive procedure for treating FLLIDH. However, as demand for this type of surgery increases, the possibility of intraoperative aggravated leg pain and compression injury of the ganglion must be considered.

Transtubular microsurgical approach to treating extraforaminal lumbar disc herniations

OBJECT

Approaches to treating extraforaminal lumbar disc herniations can be challenging due to the unique anatomy and the need to prevent spinal instability. Numerous approaches, including conventional midline, paramedian, minimally invasive, and full endoscopic approaches, have been described. The purposes of this study were to point out the outcome and clinical advantages of a transtubular microsurgical approach and to describe and illustrate this technique.

METHODS

Between 2009 and 2012, a series of 51 patients underwent a minimally invasive dilative transtubular microsurgical approach for the treatment of extraforaminal lumbar disc herniations. All patients were clinically evaluated using the visual analog scale (VAS) and Oswestry Disability Index preoperatively and 6 months postoperatively.

RESULTS

Both pain scores and functional status showed significant improvement after surgery (p < 0.001): radicular pain decreased from VAS score of 7.9 to one of 1.3, lower back pain from VAS score of 2.4 to 1.4, and the Oswestry Disability Index from 42.0 to 12.3. Subgroup analyses revealed no differences in outcome regarding obesity or timing of surgery (early vs late intervention). Highly significant was the correlation between preoperative radicular pain activity and timing of surgical intervention (p < 0.001).

CONCLUSIONS

The dilative transtubular microsurgical approach combines the advantages of the conventional open muscle-splitting approach and the endoscopic approach. The technique is easy to use with a steep learning curve. Less muscle trauma and the absence of bony resection prevent facet pain and instability, thereby contributing to a rapid recovery. Patients in this series improved excellently in the short-term follow-up.

Microendoscopic discectomy in athletes

BACKGROUND

Management of lumbar disc herniation in athletes is challenging because a prolonged period of postoperative rehabilitation prevents the athlete from participating in sporting activity, resulting in loss of competitive form. No study reporting the clinical results of microendoscopic discectomy (MED) in athletes was identified in a literature search through PubMed, in spite of the relatively long history of this treatment. The objective of this study was to evaluate the efficacy of MED for athletes, focusing on their ability to quickly resume their sports activity.

METHODS

Twenty-five competitive athletes, who underwent MED participated in this study. The level of sporting activity patients were capable of achieving, and the time until complete return to competitive level were assessed. The Japanese Orthopaedic Association (JOA) score and short form 36 (SF-36) were also evaluated.

RESULTS

Two patients did not return to sporting activity for reasons unrelated to the lumbar diseases. Among the remaining 23 cases, 19 (82.6 %) successfully returned to their original levels of sporting activity. One patient (4.4 %) could not return to his pre-injury level of sporting activity because of residual pain. He changed his field from a high school sports team to a low-level sports society. The mean period until complete return to competition was 10.8 weeks (range 5-16 weeks). Three patients (13.0 %) could not resume sporting activity because of residual pain. The mean improvement rate of JOA score at final follow-up was 80.4 %. Significant improvements in SF-36 were observed in all subscales except in general health perceptions.

CONCLUSIONS

MED is a well-balanced technique which offers a high probability of return and an early return to the same level of sporting activity, both of which are optimal aims in treatment of athletes with lumbar disc herniation.

Comparison of early and late percutaneous endoscopic lumbar discectomy for lumbar disc herniation

BACKGROUND

The optimal timing for percutaneous endoscopic lumbar discectomy (PELD) in cases of lumbar disc herniation (LDH) is debatable. This retrospective study sought to determine which category of PELD surgical intervention time resulted in greater improvement in clinical outcomes.

METHODS

We retrospectively reviewed the medical records of 145 patients who underwent PELD for single-level LDH. The patients were divided into three categories according to the duration of leg pain before surgery, the early and late group being symptomatic for ≤3 months and >3 months, ≤6 months and >6 months, ≤12 months and >12 months. Surgical time, blood loss, postoperative hospital stay, hospitalization cost, rates of reoperation due to surgical failure, Macnab criteria assessment, visual analogue scale (VAS) of back pain, leg pain and numbness, Japanese orthopedic association low back pain score (JOA) before and after surgery were compared.

RESULTS

No significant differences were found between the early and late groups according to different categories in patients' demographics, surgical time, blood loss, preoperative and postoperative VAS (lower-back pain, leg pain and numbness) scores, JOA scores and distribution of Macnab criteria assessment. Early PELD surgical intervention did not result in greater improvement of clinical outcomes. Later surgical intervention resulted in about one-third surgical failure rates for patients being symptomatic for >6 months (≤6 months, 11/96, 11.5 %; >6 months, 2/49, 4.1 %; P = 0.245) and >12 months (≤12 months, 12/120, 10.0 %; >12 months, 1/25, 4.0 %; P = 0.568) of the early surgical intervention groups. Significant difference was observed between the comorbidities and non-comorbidities group in the rate of reoperation (P = 0.040).

CONCLUSIONS

Early PELD surgical intervention did not result in greater improvement of clinical outcomes for patients with lumbar disc herniation. Later surgical intervention resulted in less failure rates for patients than the early surgical intervention groups. PELD performed when the leg pain before surgery being symptomatic for >6 months may be good for avoiding surgical failure and reducing the duration of leg pain.

Clinical success of transforaminal endoscopic discectomy with foraminotomy: a retrospective evaluation

OBJECTIVE

Transforaminal endoscopic surgery has evolved from an intradiscal procedure to a true foraminal epidural procedure where both a targeted discectomy and foraminal decompression can be performed. The success of transforaminal decompression for radiculopathy using preoperative selective nerve root block as part of a treatment algorithm for single level and multilevel lumbar disc herniations is described here.

METHODS

After Institutional Review Board Approval, charts from 195 patients with complaints of lower back and radicular pain who received one or more endoscopic discectomy procedures were reviewed. Visual Analog Scale was applied to each patient preoperatively and 6 months after the procedure.

RESULTS

Patients with multi-level pathologies receiving one procedure have an average relief of 69.7% attributed to correct diagnosis of the inflicting level as opposed to 83.9% improvement in patients with a single level herniation.

CONCLUSION

Patients with single level lumbar herniations receiving one endoscopic discectomy have excellent outcomes, but with a good response to a selective nerve root block as a preoperative adjunct, patients with multilevel disc herniations also have significant benefit from single level endoscopic discectomy.

Clinical outcomes of percutaneous endoscopic surgery for lumbar discal cyst

OBJECTIVE

Discal cyst is rare and causes indistinguishable symptoms from lumbar disc herniation. The clinical manifestations and pathological features of discal cyst have not yet been completely known. Discal cyst has been treated with surgery or with direct intervention such as computed tomography (CT) guided aspiration and steroid injection. The purpose of this study is to evaluate the safety and efficacy of the percutaneous endoscopic surgery for lumbar discal cyst over at least 6 months follow-up.

METHODS

All 8 cases of discal cyst with radiculopathy were treated by percutaneous endoscopic surgery by transforaminal approach. The involved levels include L5-S1 in 1 patient, L3-4 in 2, and L4-5 in 5. The preoperative magnetic resonance imaging and 3-dimensional CT with discogram images in all cases showed a connection between the cyst and the involved intervertebral disc. Over a 6-months period, self-reported measures were assessed using an outcome questionaire that incorporated total back-related medical resource utilization and improvement of leg pain [visual analogue scale (VAS) and Macnab's criteria].

RESULTS

All 8 patients underwent endoscopic excision of the cyst with additional partial discectomy. Seven patients obtained immediate relief of symptoms after removal of the cyst by endoscopic approach. There were no recurrent lesions during follow-up period. The mean preoperative VAS for leg pain was 8.25±0.5. At the last examination followed longer than 6 month, the mean VAS for leg pain was 2.25±2.21. According to MacNab' criteria, 4 patients (50%) had excellent results, 3 patients (37.5%) had good results; thus, satisfactory results were achieved in 7 patients (87.5%). However, one case had unsatisfactory result with persistent leg pain and another paresthesia.

CONCLUSION

The radicular symptoms were remarkably improved in most patients immediately after percutaneous endoscopic cystectomy by transforaminal approach.

The efficacy of minimally invasive discectomy compared with open discectomy: a meta-analysis of prospective randomized controlled trials

OBJECT

Advocates of minimally invasive discectomy (MID) have promoted this operation as an alternative to open discectomy (OD), arguing that there may be less injury to the paraspinal muscles, decreased postoperative pain, and a faster recovery time. However, a recently published large randomized controlled trial (RCT) comparing these approaches reported inferior relief of leg pain in patients undergoing MID. The authors conducted a meta-analysis to evaluate complications and improvement in leg pain in patients with radiculopathy enrolled in RCTs comparing OD to MID.

METHODS

The authors performed a literature search using Medline and EMBASE of studies indexed between January 1990 and January 2011. Predetermined RCT eligibility included the usage of tubular retractors during MID, a minimum follow-up duration of 1 year, and quantification of pain with the visual analog scale (VAS). Trials that only evaluated patients with recurrent disc herniation were excluded. Data on operative parameters, complications, and VAS scores of leg pain were extracted by 2 investigators. A meta-analysis was performed assuming random effects to determine the difference in mean change for continuous outcomes and the risk ratio for binary outcomes.

RESULTS

Six trials comprising 837 patients (of whom 388 were randomized to MID and 449 were randomized to OD) were included. The mean operative time was 49 minutes during MID and 44 minutes during OD; this difference was not statistically significant. Incidental durotomies occurred significantly more frequently during MID (5.67% compared with 2.90% for OD; RR 2.05, 95% CI 1.05-3.98). Intraoperative complications (incidental durotomies and nerve root injuries) were also significantly more common in patients undergoing MID (RR 2.01, 95% CI 1.07-3.77). The mean preoperative VAS score for leg pain was 6.9 in patients randomized to MID and 7.2 in those randomized to OD. With long-term follow-up (1-2 years postoperatively), the mean VAS score improved to 1.6 in both the MID and OD cohorts. There was no significant difference in relief of leg pain between the 2 approaches with either short-term follow-up (2-3 months postoperatively, 0.81 points on the VAS, 95% CI -4.71 to 6.32) or long-term follow-up (2.64 on the VAS, 95% CI -2.15 to 7.43). Reoperation for recurrent herniation was more common in patients randomized to the MID group (8.50% compared with 5.35% in patients randomized to the OD group), but this difference was not statistically significant (RR 1.56, 95% CI 0.92-2.66). Total complications did not differ significantly between the operations (RR 1.50, 95% CI 0.97-2.33).

CONCLUSIONS

The current evidence suggests that both OD and MID lead to a substantial and equivalent long-term improvement in leg pain. Adequate decompression, regardless of the operative approach used, may be the primary determinant of pain relief-the major complaint of many patients with radiculopathy. Incidental durotomies occurred significantly more frequently during MID, but total complications did not differ between the techniques.

Ultra-long-term outcome of surgically treated far-lateral, extraforaminal lumbar disc herniations: a single-center series

PURPOSE

Far-lateral extraforaminal lumbar disc herniation is an uncommon cause of nerve root entrapment, and studies addressing the long-term outcome of surgically treated patients are few. The purpose of this study was to analyze the ultra-long-term outcome of patients who were treated via a lateral approach.

METHODS

The medical reports of 138 consecutive patients were analyzed with regard to signs and symptoms, operative findings, complications, and short-term outcome (6 weeks). To assess long-term results, standardized telephone interviews were performed using a structured questionnaire. The patients were questioned about pain using the verbal rating scale and persisting symptoms, if any. Other queries were related to the Oswestry Disability Index. Subjective satisfaction with the result of surgery was classified as excellent (no pain), good (some pain), fair (moderate pain), and poor (unchanged or worse) based on MacNab classification.

RESULTS

At short-term follow-up, major and moderate leg pain had decreased from 99.3 to 5.1% and low back pain from 97.8 to 2.8%. Sensory and motor deficits, however, were still present in the majority of patients. A total of 87 telephone interviews were conducted, and the mean follow-up was 146 months. As many as 49 patients (56.3%) reported complete relief of symptoms, 14 patients (16.1%) had minor ailments under physical stress, and 24 patients (27.6%) had permanent residual symptoms. The most common complaint was remaining sensory disturbance. Despite residual symptoms, the vast majority of patients expressed satisfaction with the result of surgery. The outcome was subjectively rated as follows: 75.9% excellent (66 patients), 18.4% good (16 patients), 4.6% fair (4 patients), and 1.1% poor (1 patient).

CONCLUSIONS

The lateral approach is a minimally invasive and safe procedure with low complication rates. The profit from surgery is maintained beyond the usual postoperative observation periods. Thus, ultimate outcome at ultra-long-term follow-up is very gratifying in the vast majority of patients.

Revisional percutaneous full endoscopic disc surgery for recurrent herniation of previous open lumbar discectomy

Study Design

A retrospective study.

Purpose

To determine the feasibility and effectiveness of revisional percutaneous full endoscopic discectomy for recurrent herniation after conventional open disc surgery.

Overview of the Literature

Repeated open discectomy with or without fusion has been the most common procedure for recurrent lumbar disc herniation. Percutaneous endoscopic lumbar discectomy for recurrent herniation has been thought of as an impossible procedure. Despite good results with open revisional surgery, major problems may be caused by injuries to the posterior stabilized structures. Our team did revisional full endoscopic lumbar disc surgery on the basis of our experience doing primary full endoscopic disc surgery.

Methods

Between February 2004 and August 2009 a total of 41 patients in our hospital underwent revisional percutaneous endoscopic lumbar discectomy using a YESS endoscopic system and a micro-osteotome (designed by the authors). Indications for surgery were recurrent disc herniation following conventional open discectomy; with compression of the nerve root revealed by Gadolinium-enhanced magnetic resonance imaging; corresponding radiating pain which was not alleviated after conservative management over 6 weeks. Patients with severe neurologic deficits and isolated back pain were excluded.

Results

The mean follow-up period was 16 months (range, 13 to 42 months). The visual analog scale for pain in the leg and back showed significant post-treatment improvement (p < 0.001). Based on a modified version of MacNab's criteria, 90.2% showed excellent or good outcomes. There was no measurable blood loss. There were two cases of recurrence of and four cases with complications.

Conclusions

Percutaneous full-endoscopic revisional disc surgery without additional structural damage is feasible and effective in terms of there being less chance of fusion and bleeding. This technique can be an alternative to conventional repeated discectomy.

Extreme-lateral, minimally invasive, transpsoas approach for the treatment of far-lateral lumbar disc herniation

The authors present 2 cases of far-lateral lumbar disc herniations treated surgically via an extreme-lateral transpsoas approach. The procedure was performed using the MaXcess minimally invasive retractor system to access and successfully remove the disc fragments without complication. To the authors' knowledge, these are the first reported cases of using a minimally invasive retroperitoneal approach for the treatment of far-lateral disc herniations.

Strategies for Noncontained Lumbar Disc Herniation by an Endoscopic Approach : Transforaminal Suprapedicular Approach, Semi-Rigid Flexible Curved Probe, and 3-Dimensional Reconstruction CT with Discogram

OBJECTIVE

The purpose of this study was to evaluate the efficacy of a transforaminal suprapedicular approach, semi-rigid flexible curved probe, and 3-dimensional reconstruction computed tomography (3D-CT) with discogram in the endoscopic treatment of non-contained lumbar disc herniations.

METHODS

The subjects were 153 patients with difficult, non-contained lumbar disc herniations undergoing endoscopic treatment. The types of herniation were as follows : extraforaminal, 17 patients; foraminal, 21 patients; high grade migration, 59 patients; and high canal compromise, 56 patients. To overcome the difficulties in endoscopic treatment, the anatomic structures were analyzed by 3D reconstruction CT and the high grade disc was extracted using a semi-rigid flexible curved probe and a transforaminal suprapedicular approach.

RESULTS

The mean follow-up was 18.3 months. The mean visual analogue scale (VAS) of the patients prior to surgery was 9.48, and the mean postoperative VAS was 1.63. According to Macnab's criteria, 145 patients had excellent and good results, and thus satisfactory results were obtained in 94.77% cases.

CONCLUSION

In a posterolateral endoscopic lumbar discectomy, the difficult, non-contained disc is considered to be the most important factor impeding the success of surgery. By applying a semi-rigid flexible curved probe and using a transforaminal suprapedicular approach, good surgical results can be obtained, even in high grade, non-contained disc herniations.

Transforaminal endoscopic surgery for symptomatic lumbar disc herniations: a systematic review of the literature

The study design includes a systematic literature review. The objective of the study was to evaluate the effectiveness of transforaminal endoscopic surgery and to compare this with open microdiscectomy in patients with symptomatic lumbar disc herniations. Transforaminal endoscopic techniques for patients with symptomatic lumbar disc herniations have become increasingly popular. The literature has not yet been systematically reviewed. A comprehensive systematic literature search of the MEDLINE and EMBASE databases was performed up to May 2008. Two reviewers independently checked all retrieved titles and abstracts and relevant full text articles for inclusion criteria. Included articles were assessed for quality and outcomes were extracted by the two reviewers independently. One randomized controlled trial, 7 non-randomized controlled trials and 31 observational studies were identified. Studies were heterogeneous regarding patient selection, indications, operation techniques, follow-up period and outcome measures and the methodological quality of these studies was poor. The eight trials did not find any statistically significant differences in leg pain reduction between the transforaminal endoscopic surgery group (89%) and the open microdiscectomy group (87%); overall improvement (84 vs. 78%), re-operation rate (6.8 vs. 4.7%) and complication rate (1.5 vs. 1%), respectively. In conclusion, current evidence on the effectiveness of transforaminal endoscopic surgery is poor and does not provide valid information to either support or refute using this type of surgery in patients with symptomatic lumbar disc herniations. High-quality randomized controlled trials with sufficiently large sample sizes are direly needed to evaluate if transforaminal endoscopic surgery is more effective than open microdiscectomy.