Surgical treatment of far lateral lumbar disc herniation. Identification of compressed root and discectomy by lateral approach

Comparative Analysis on Surgical Operability and Degree of Exposure of Microsurgical Approaches to Intraforaminal Lumbar Disk Herniations

BACKGROUND

 Intraforaminal lumbar disk herniations (IFDHs) represent a heterogeneous and relatively uncommon disease; their treatment is technically demanding due to the anatomical relationships with nerve roots and vertebral joints. Over time, several approaches have been developed without reaching a consensus about the best treatment strategy.

MATERIALS AND METHODS

 Authors comparatively analyze surgical operability and exposure in terms of quantitative variables between the different microsurgical approaches to IFDHs, defining the impact of each approach on surgical maneuverability and exposure on specific targets.A comparative microanatomical laboratory investigation was conducted. The operability score (OS) was applied for quantitative analysis of surgical operability.

RESULTS

 Transarticular and combined translaminar-trans-pars-interarticularis approaches result in providing the best surgical exposure and maneuverability on all targets with surgical controls on both nerve roots, at the expense of a higher risk of iatrogenic instability. Trans-pars-interarticularis approach reaches comparable levels of operability, even limited to the pure foraminal area (lateral compartment); similar findings were recorded for partial facetectomy on the medial compartment. The contralateral interlaminar approach provides good visualization of the foramen without consensual favorable maneuverability, which should be considered the main drawback.

CONCLUSIONS

 Approach selection has to consider disease location, the possible migration of disk fragments, the degree of nerve root involvement, and risk of iatrogenic instability. According to the findings, authors propose an operative algorithm to tailor the surgical strategy, based both on the precise definition of anatomic boundaries of exposure of each approach and on surgical maneuverability on specific targets.

Percutaneous Endoscopic Discectomy Via a Transforaminal Approach for L5/S1 Far-Lateral Disc Herniation Assisted by Intraoperative Computed Tomography

OBJECTIVE

To examine the clinical outcomes of a percutaneous lumbar transforaminal endoscopic discectomy (PTED) with intraoperative computed tomography (iCT) navigation for the treatment of L5-S1 far-lateral lumbar disc herniation (LDH).

METHODS

A total of 30 patients with L5-S1 far-lateral LDH who underwent PTED with iCT navigation from September 2016 to October 2020 were enrolled in this study. Outcomes were assessed using the visual analog scale pain score, the Oswestry Disability Index, the Japanese Orthopedic Association score, the EQ-5D-5 L and the modified Macnab criteria. Preoperative and postoperative complications were recorded.

RESULTS

The mean visual analog scale score for leg pain improved from 8.1 at baseline to 2.3, 0.9, 0.7 and 0.9 at 1 day, 1 week, 6 months, and 12 months postoperatively, respectively (P < 0.01). The mean Oswestry Disability Index improved from 78.1% at baseline to 45.5%, 21.9%, 12.6%, and 11.7% at 1 week, 1 month, 6 months, and 12 months postoperatively, respectively (P < 0.01); and the mean Japanese Orthopedic Association score improved from 8.6 at baseline to 14.2, 20.2, 24.4, and 25.6 at 1 day, 1 week, 6 months, and 12 months postoperatively, respectively (P < 0.01). At 12 months postoperatively, the EQ-5D-5 L value significantly increased, from -0.061 ± 0.138 to 0.903 ± 0.064. The rate of a good or excellent modified Macnab result was 93% (26/28) at 12 months postoperatively. In the present study, combined L5-S1 foraminal stenosis tended to lead poor outcomes, which required more postsurgical treatments.

CONCLUSIONS

With iCT navigation, PTED is a feasible and effective minimally invasive surgery for L5-S1 far-lateral LDH.

Surgical Outcomes of Extraforaminal Microdiskectomy by Midline Incision for Far-Lateral Lumbar Disk Herniation

BACKGROUND

 Far-lateral lumbar disk herniation (FLDH) is defined as a disk herniation located laterally to the medial wall of the pedicle. The aim of our study is to describe the extraforaminal microdiskectomy by midline incision for FLDH, which does not include laminotomy-partial facetectomy, and to evaluate mid-term surgical outcomes.

METHODS

 107 patients who underwent surgery for FLDH by midline incision for the first time between 2012 and 2017 were included in our study. The assessment of neurological status of the patients was done by physical examination, preoperative Oswestry Disability Index (ODI), Visual Analog Scala (VAS) scores, and magnetic resonance images. They were then followed-up postoperatively and at 12 months with VAS and ODI tests.

RESULT

 58 (54.2%) patients were male and 49 (45.8%) were female. The mean age at the time of surgery was 55.0 ± 8.6 years. The mean ODI scale score was 32.4 ± 6.2 preoperatively, 11.4 ± 2.1 early postoperatively, and 9.7 ± 2.2 in late postoperative follow-up (statistically significant, p = 0.001). The average VAS was 7.51 ± 1.1 preoperatively, 2.74 ± 0.7 early postoperatively, and 0.68 ± 0.08 in late postoperative follow-up (statistically significant, p = 0.001). The average operative time was 41 ± 7 (37 to 58) minutes.

CONCLUSIONS

 The extraforaminal microdiskectomy without laminotomy by midline incision is a minimally invasive approach for FLDH. Our technique allows a sufficient and safe decompression of the neural structures, and thus results in a significant reduction of the symptoms and disability.

Clinical Presentation and Outcomes of Patients With a Lumbar Far Lateral Herniated Nucleus Pulposus as Compared to Those With a Central or Paracentral Herniation

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

Examine pre- and postoperative outcomes between patients presenting with a central/paracentral versus a far lateral herniated nucleus pulposus (HNP) and assess whether significantly worse postoperative outcomes, assessed via patient self-reported survey, are associated with far lateral disc herniations.

METHODS

We performed a retrospective cohort analysis of patients who underwent primary lumbar decompression between January 2008 and December 2015. Groups were divided based on herniation type, central/paracentral or far lateral. Patients with 3 months, or longer, of follow-up were included. Variables analyzed included demographics, American Society of Anesthesiologists (ASA) Score, Charleston Comorbidity Index (CCI), Oswestry Disability Index (ODI) scores, Visual Analog Scales (VAS) scores for the back and leg, 12-Item Short Form Mental and Physical Survey (SF-12) scores, and Veterans RAND 12-Item Mental and Physical Survey (VR-12) scores.

RESULTS

A total of 100 patients met the inclusion criteria. Postoperative ODI scores for central/paracentral HNP were significantly lower compared to far lateral HNP. Patients with a far lateral disc herniation presented with significantly lower preoperative SF-12 and VR-12 scores. The improvement in ODI score from preoperative to final was significantly lower in the patients presenting with a far lateral HNP.

CONCLUSIONS

Although patients with far lateral HNP present with worse preoperative outcome scores, they can expect similar symptom improvement to central or paracentral herniations following discectomy. This information can be used for future surgeons when weighing conservative versus surgical treatment of far lateral herniations.

Clinical and Radiological Outcomes of Foraminal Decompression Using Unilateral Biportal Endoscopic Spine Surgery for Lumbar Foraminal Stenosis

Background

Since open Wiltse approach allows limited visualization for foraminal stenosis leading to an incomplete decompression, we report the short-term clinical and radiological results of unilateral biportal endoscopic foraminal decompression using 0° or 30° endoscopy with better visualization.

Methods

We examined 31 patients that underwent surgery for neurological symptoms due to lumbar foraminal stenosis which was refractory to 6 weeks of conservative treatment. All 31 patients underwent unilateral biportal endoscopic far-lateral decompression (UBEFLD). One portal was used for viewing purpose, and the other was for surgical instruments. Unilateral foraminotomy was performed under guidance of 0° or 30° endoscopy. Clinical outcomes were analyzed using the modified Macnab criteria, Oswestry disability index, and visual analogue scale. Plain radiographs obtained preoperatively and 1 year postoperatively were compared to analyze the intervertebral angle (IVA), dynamic IVA, percentage of slip, dynamic percentage of slip (gap between the percentage of slip on flexion and extension views), slip angle, disc height index (DHI), and foraminal height index (FHI).

Results

The IVA significantly increased from 6.24° ± 4.27° to 6.96° ± 3.58° at 1 year postoperatively (p = 0.306). The dynamic IVA slightly decreased from 6.27° ± 3.12° to 6.04° ± 2.41°, but the difference was not statistically significant (p = 0.375). The percentage of slip was 3.41% ± 5.24% preoperatively and 6.01% ± 1.43% at 1-year follow-up (p = 0.227), showing no significant difference. The preoperative dynamic percentage of slip was 2.90% ± 3.37%; at 1 year postoperatively, it was 3.13% ± 4.11% (p = 0.720), showing no significant difference. The DHI changed from 34.78% ± 9.54% preoperatively to 35.05% ± 8.83% postoperatively, which was not statistically significant (p = 0.837). In addition, the FHI slightly decreased from 55.15% ± 9.45% preoperatively to 54.56% ± 9.86% postoperatively, but the results were not statistically significant (p = 0.705).

Conclusions

UBEFLD using endoscopy showed a satisfactory clinical outcome after 1-year follow-up and did not induce postoperative segmental spinal instability. It could be a feasible alternative to conventional open decompression or fusion surgery for lumbar foraminal stenosis.

Laser-Assisted Microdiscectomy for Far Lateral Lumbar Disc Herniation at the L5-S1 Level

OBJECTIVE

Laser-assisted paraspinal microdiscectomy for far lateral lumbar disc herniation (LDH) enables direct access to the foraminal or far lateral zone with minimal tissue injury and preserves facet joints, thereby preventing postoperative segmental instability. We demonstrated the clinical outcomes of this technique and discussed the pros and cons of laser use in lumbar disc surgery.

BACKGROUND

The microdiscectomy technique for L5-S1 far lateral zone may be difficult due to the limited surgical field with narrowed disc space, hypertrophied facet, and sacral ala. Thus, we used carbon dioxide (CO₂) laser for sophisticated decompression.

METHODS

Eighty-four patients who were treated with microdiscectomy for far lateral LDH at the L5-S1 level were evaluated. Among them, 40 patients were treated using CO₂ laser-assisted microdiscectomy, and the remaining 44 patients using conventional microdiscectomy. Perioperative and postoperative data were compared between the two groups with 2 years of follow-up. Clinical outcomes were assessed using the visual analog scale (VAS), Oswestry disability index (ODI), and modified Macnab criteria.

RESULTS

VAS and ODI significantly improved in both groups. An excellent or good outcome was rated in 80% and 77.3% of the laser and conventional group, respectively. There was no significant difference in global outcomes. However, hospital stay and time to return to work were significantly shorter in the laser group (p < 0.05).

CONCLUSIONS

CO₂ laser-assisted paraspinal microdiscectomy is effective for treating far lateral LDH. The pinpoint laser scalpel enables delicate and complete decompression in a limited surgical field with minimal tissue trauma.

Extraforaminal approach of biportal endoscopic spinal surgery: a new endoscopic technique for transforaminal decompression and discectomy

This study was performed to describe the extraforaminal approach of biportal endoscopic spinal surgery (BESS) as a new endoscopic technique for transforaminal decompression and discectomy and to demonstrate the clinical outcomes of this new procedure for the first time. Twenty-one patients (27 segments) who underwent the extraforaminal approach of BESS between March 2015 and April 2016 were enrolled according to the inclusion and exclusion criteria. The operative time (minutes/level) and complications after the procedure were recorded. The visual analog scale (VAS) score was checked to assess the degree of radicular leg pain preoperatively and at the time of the last follow-up. The modified Macnab criteria were used to examine the clinical outcomes at the time of the last follow-up. The mean duration of the follow-up period was 14.8 months (minimum duration 12 months). The mean operative time was 96.7 minutes for one level. The mean VAS score for radicular leg pain dropped from a preoperative score of 7.5 ± 0.9 to a final follow-up score of 2.5 ± 1.2 (p < 0.001). The final outcome according to the modified Macnab criteria was excellent in 5 patients (23.8%), good in 12 (57.2%), fair in 4 (19.0%), and poor in 0. Therefore, excellent or good results (a satisfied outcome) were obtained in 80.9% of the patients. Complications were limited to one dural tear (4.8%). The authors found that the extraforaminal approach of BESS was a feasible and advantageous endoscopic technique for the treatment of foraminal lesions, including stenosis and disc herniation. They suggest that this technique represents a useful, alternative, minimally invasive method that can be used to treat lumbar foraminal stenosis and disc herniation.

Minimally Invasive Transtubular Endoscopic Decompression for L5 Radiculopathy Induced by Lumbosacral Extraforaminal Lesions

Study Design

Retrospective study.

Purpose

This study aimed to evaluate the efficacy of minimally invasive transtubular endoscopic decompression for the treatment of lumbosacral extraforaminal lesion (LSEFL).

Overview of Literature

Conventional procedures for surgical decompression for the treatment of LSEFL involve certain technical challenges because the lumbosacral extraforaminal region has unique anatomical features. Moreover, the efficacy of minimally invasive procedures performed via the posterolateral approach for LSEFL has been reported.

Methods

Twenty-five patients who had undergone minimally invasive transtubular endoscopic decompression for the treatment of LSEFL and could be followed up for at least 1 year postoperatively were enrolled. Five of these patients had a history of lumbar surgery, and seven had concomitant adjacent-level spinal stenosis. The clinical outcomes were evaluated using the Japanese Orthopaedic Association (JOA) lumbar score, numeric rating scale (NRS), and the JOA Back Pain Evaluation Questionnaire (JOABPEQ). The mean postoperative follow-up (FU) duration was 3.8 years.

Results

All procedures could be completed without any severe surgical complications, and all patients could resume their previous activity level within 1 month postoperatively. The JOA score significantly increased from 14.1±4.0 at baseline to 23.1±3.7 at the 1-year FU and 22.1±3.8 at the last FU. Similarly, there were significant improvements in the postoperative NRS and JOABPEQ scores. An additional surgery was performed in two patients (8%) during the FU period. Patients with degenerative scoliosis exhibited significantly poorer outcomes compared with those without this condition.

Conclusions

Transtubular endoscopic decompression can overcome certain technical challenges involved in the conventional procedures for LSEFL treatment; therefore, it can be recommended as a useful procedure for treating LSEFL. This procedure can provide some benefits to LSEFL patients and offer a well-illuminated surgical field and high surgical safety for the surgeon. However, the procedure should be carefully adapted for LSEFL patients with concomitant degenerative scoliosis.

Radiographic Assessment on Magnetic Resonance Imaging after Percutaneous Endoscopic Lumbar Foraminotomy

Percutaneous endoscopic lumbar foraminotomy (ELF) is a novel minimally invasive technique used to treat lumbar foraminal stenosis. However, the validity of foraminal decompression based on quantitative assessment using magnetic resonance imaging (MRI) has not yet been established. The objective of this study was to investigate the radiographic efficiency of ELF using MRI. Radiographic changes of neuroforamen were measured based on pre- and postoperative MRI findings. Images were blindly analyzed by two observers for foraminal stenosis grade and foraminal dimensions. The intraclass correlation coefficient (ICC) and k statistic were calculated to determine interobserver agreement. Thirty-five patients with 40 neuroforamen were evaluated. The mean visual analog scale (VAS) score improved from 8.4 to 2.1, and the mean Oswestry disability index (ODI) improved from 65.9 to 19.2. Overall, 91.4% of the patients achieved good or excellent outcomes. The mean grade of foraminal stenosis significantly improved from 2.63 to 0.68. There were significant increases in the mean foraminal area (FA) from 50.05 to 92.03 mm², in mean foraminal height (FH) from 11.36 to 13.47 mm, in mean superior foraminal width (SFW) from 6.43 to 9.27 mm, and in mean middle foraminal width (MFW) from 1.47 to 78 mm (P < 0.001). Interobserver agreements for preoperative and postoperative measurements were good to excellent with the exception of SFW. In conclusion, foraminal dimensions and grades of foraminal stenosis significantly improved after ELF. These findings may enhance the clinical relevance of endoscopic lumbar foraminal decompression.

Surgical treatment of intraforaminal/extraforaminal lumbar disc herniations: Many approaches for few surgical routes

BACKGROUND

Several disc disease nomenclatures and approaches for LDH exist. The traditional midline bone-destructive procedures together with approaches requiring extreme muscular retraction are being replaced by muscle sparing, targeted, stability-preserving surgical routes. The increasing speculation on LDHs and the innovative corridors described to treat them have lead to an extensive production of papers frequently treating the same topic but adopting different terminologies and reporting contradictory results.

METHODS

The review of such literature somehow confounding gave us the chance to regroup by surgical corridors the vast amount of approaches for LDH differently renamed over time. Likewise, LDHs were simplified in intra-foraminal (ILDH), extra-foraminal (ELDH), and intra-/extra-foraminal (IELDH) in relation to precise anatomical boundaries and extent of bulging disc.

RESULTS

Through the analysis of the papers, it was possible to identify ideal surgical corridors for ILDHs, ELDHs, and IELDHs, distinguishing for each approach the exposure provided and the technical advantages/disadvantages in terms of muscle trauma, biomechanical stability, and nerve root preservation. A significant disproportion was noted between studies discussing traditional midline approaches or variants of the posterolateral route and those investigating pros and cons of simple or combined alternative corridors. Although rarely discussed, these latter represent valuable strategies particularly for the challenging IELDHs, thanks to the optimal compromise between herniation exposure and bone-muscle preservation.

CONCLUSIONS

The integration of adequate mastery of traditional approaches together with a greater confidence through unfamiliar surgical corridors can improve the development of combined mini-invasive procedures, which seem promising for future targeted LDH excisions.

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.

Microsurgical Foraminotomy via Wiltse Paraspinal Approach for Foraminal or Extraforaminal Stenosis at L5-S1 Level : Risk Factor Analysis for Poor Outcome

Objective

The purpose of this study was to present the outcome of the microsurgical foraminotomy via Wiltse paraspinal approach for foraminal or extraforaminal (FEF) stenosis at L5–S1 level. We investigated risk factors associated with poor outcome of microsurgical foraminotomy at L5–S1 level.

Methods

We analyzed 21 patients who underwent the microsurgical foraminotomy for FEF stenosis at L5–S1 level. To investigate risk factors associated with poor outcome, patients were classified into two groups (success and failure in foraminotomy). Clinical outcomes were assessed by the visual analogue scale (VAS) scores of back and leg pain and Oswestry disability index (ODI). Radiographic parameters including existence of spondylolisthesis, existence and degree of coronal wedging, disc height, foramen height, segmental lordotic angle (SLA) on neutral and dynamic view, segmental range of motion, and global lumbar lordotic angle were investigated.

Results

Postoperative VAS score and ODI improved after foraminotomy. However, there were 7 patients (33%) who had persistent or recurrent leg pain. SLA on neutral and extension radiographic films were significantly associated with the failure in foraminotomy (p<0.05). Receiver-operating characteristics curve analysis revealed the optimal cut-off values of SLA on neutral and extension radiographic films for predicting failure in foraminotomy were 17.3° and 24°s, respectively.

Conclusion

Microsurgical foraminotomy for FEF stenosis at L5–S1 level can provide good clinical outcomes in selected patients. Poor outcomes were associated with large SLA on preoperative neutral (>17.3°) and extension radiographic films (>24°).

Percutaneous endoscopic lumbar foraminotomy: an advanced surgical technique and clinical outcomes

Supplemental Digital Content is Available in the Text.

BACKGROUND:

Although several authors have reported the use of endoscopic techniques to treat lumbar foraminal stenosis, the practical application of these techniques has been limited to soft disc herniation.

OBJECTIVE:

To describe the details of the percutaneous endoscopic lumbar foraminotomy (ELF) technique for bony foraminal stenosis and to demonstrate the clinical outcomes.

METHODS:

Two years of prospective data were collected from 33 consecutive patients with lumbar foraminal stenosis who underwent ELF. The surgical outcomes were assessed using the visual analog scale, Oswestry Disability Index, and modified MacNab criteria. The procedure begins at the safer extraforaminal zone rather than the riskier intraforaminal zone. Then, a full-scale foraminal decompression can be performed using a burr and punches under endoscopic control.

RESULTS:

The mean age of the 18 female and 15 male patients was 64.2 years. The mean visual analog scale score for leg pain improved from 8.36 at baseline to 3.36 at 6 weeks, 2.03 at 1 year, and 1.97 at 2 years post-surgery (P < .001). The mean Oswestry Disability Index improved from 65.8 at baseline to 31.6 at 6 weeks, 19.7 at 1 year, and 19.3 at 2 years post-surgery (P < .001). Based on the modified MacNab criteria, excellent or good results were obtained in 81.8% of the patients, and symptomatic improvements were obtained in 93.9%.

CONCLUSION:

Percutaneous ELF under local anesthesia could be an efficacious surgical procedure for the treatment of foraminal stenosis. This procedure may offer safe and reproducible results, especially for elderly or medically compromised patients.

ABBREVIATIONS:

ELF,endoscopic lumbar foraminotomy

ODI, Oswestry Disability Index

VAS, visual analog scale

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.

Lumbar extraforaminal decompression: A technical note and retrospective study looking at potential complications as an outpatient procedure

BACKGROUND

Lumbar disc herniation and stenosis that results in compression of a nerve root lateral to the foramen is defined as extraforaminal. In recent years the recognition of such pathology has increased with technology and greater awareness. Various approaches and techniques have been developed for extraforaminal decompression in the lumbar region. The purpose of this study was two fold: 1) Determine the safety of treating patients operatively via a paramedian muscle splitting approach on an outpatient basis, and 2) Highlight the technical aspects of the approach to the extraforaminal region.

METHODS

One hundred consecutive extraforaminal decompressions were performed from 1992 to 2007 by a single surgeon. A retrospective review was performed consisting of chart reviews. Summary statistics and the Pierson Chi-square test were used to analyze the data. The primary outcome measure was the need for hospital admission or readmission following surgical decompression.

RESULTS

Seven of 100 patients (7%) were required to remain in the hospital for twenty-three hour observation due to Medicare requirements. Five (5%) of the patients originally scheduled for an outpatient procedure were converted to inpatient status due to postoperative pain. All were released within 2 days (average 1.25 days). Only one (1%) patient was readmitted for urinary retention that resolved without incident. There was no significant difference (P = 0.137) in complication rate between our control and those that underwent extraforaminal decompression.

CONCLUSIONS

Extraforaminal lumbar decompression as an outpatient procedure can be done safely without the need for hospital admission.

Minimally invasive approach to extraforaminal disc herniations at the lumbosacral junction using an operating microscope: case series and review of the literature

Surgical access to extraforaminal lumbar disc herniations is complicated due to the unique anatomical constraints of the region. Minimizing complications during microdiscectomies at the level of L5–S1 in particular remains a challenge. The authors report on a small series of patients and provide a video presentation of a minimally invasive approach to L5–S1 extraforaminal lumbar disc herniations utilizing a tubular retractor with microscopic visualization.

A minimally invasive technique for L5–S1 intraforaminal disc herniations: microdiscectomy with a tubular retractor via a contralateral approach

✓ Surgical treatment of intraforaminal disc herniations at the L5–S1 level is technically demanding. The 2 most commonly used procedures involve either a medial or lateral ipsilateral approach and often require a partial or even complete facet resection, which may in turn result in vertebral instability and/or back pain, as well as, in some cases, a fusion or stabilization procedure. In this report, the authors present a new minimally invasive technique for the treatment of L5–S1 intraforaminal disc herniations. Using this technique, which involves tubular retractors and an operative microscope to approach the neural foramen from the contralateral side, the authors could easily visualize and remove the herniated disc material and perform a thorough microdiscectomy with minimal resection of osseous and ligamentous structures. To illustrate this new minimally invasive technique for the treatment of intraforaminal disc herniations at L5–S1, they describe the cases of 2 patients who underwent the procedure and in whom successful results were achieved.

Minimally invasive far lateral microendoscopic discectomy for extraforaminal disc herniation at the lumbosacral junction: cadaveric dissection and technical case report

BACKGROUND CONTEXT

Extraforaminal lumbar disc herniations (ELDHs) at the lumbosacral junction are an uncommon cause of L5 radiculopathy. The surgical anatomy of the extraforaminal space at L5-S1 is uniquely challenging for the various open surgical approaches that have been described for ELDHs in general. Reports specifically describing minimally invasive surgical approaches to lumbosacral ELDHs are lacking.

PURPOSE

To report the novel use of a far lateral microendoscopic (FLMED) approach to lumbosacral ELDH. To better define the unique anatomical features of extraforaminal approaches to the lumbosacral junction as they apply to minimal access techniques.

STUDY DESIGN/SETTING

A cadaveric investigation and clinical case were performed at a single institution. A thorough review of the literature was conducted.

PATIENT SAMPLE

A single patient with an extraforaminal disc herniation at the lumbosacral junction underwent evaluation and surgery.

OUTCOME MEASURES

The patient's self-reported pain levels were documented. Physiologic outcome was judged on pre- and postoperative motor and sensory examinations. Functional capacity was assessed by work status and ability to perform activities of daily living.

METHODS

FLMED was performed in two fresh human cadavers at the lumbosacral junction. Qualitative assessments of the surgical anatomy were made, and intraoperative fluoroscopy and endoscopic photographs were obtained to document the findings. A patient with refractory pain and sensorimotor deficits from compression of the L5 nerve root by an ELDH underwent FLMED. The literature was carefully reviewed for the epidemiology of ELDHs at the lumbosacral junction and the surgical techniques used to treat them.

RESULTS

The posterolateral surgical corridor to the lumbosacral disc was consistently constrained by the sacral ala and to a lesser extent the lateral facet and L5 transverse process. Resection of the superior ala exposed the exiting nerve root and provided ample access to the disc. In the clinical case, the patient enjoyed immediate pain relief, was discharged in 3 hours, and returned to full work and social activities. Follow-up neurological examination revealed no sensory or motor deficit.

CONCLUSIONS

FLMED offers a safe and efficacious approach to ELDHs at the lumbosacral junction by combining satisfactory visualization for adequate resection of the sacral ala with the benefits of reduced tissue injury and faster recovery times that accompany minimally invasive techniques.

Risk factor for unsatisfactory outcome after lumbar foraminal and far lateral microdecompression

STUDY DESIGN

A retrospective study of consecutive patients who underwent microdecompression for far lateral disc or foraminal stenosis.

OBJECTIVES

To evaluate the risk factors for unsatisfactory outcome.

SUMMARY OF BACKGROUND DATA

There has been no detailed analysis of postoperative radicular pain, although it is not infrequent following foraminal and far lateral microdecompression.

METHODS

A total of 184 patients, who were followed up for more than 2 years, were reviewed. Microdecompression was performed through lateral intermuscular approach. In cases of double herniation (combination of intracanalicular disc at the same level), additional intracanalicular decompression was simultaneously performed. The unsatisfactory outcomes included persistent or recurrent leg pain, based on the Japanese Orthopedic Association leg pain score, and revision surgery at the same level. The potential risk factors, including gender, age, symptom period, preoperative radiologic and intraoperative findings, were determined.

RESULTS

The average follow-up period was 38.4 months, with a maximum 70 months. Forty of the 184 patients (21.7%) had persistent or recurrent leg pain, with nine requiring revision surgeries. The statistically significant risk factor for unfavorable outcomes was double herniation, with odds ratio of 2.89 (P = 0.004).

CONCLUSION

Facet preserving microdecompression is an effective method for foraminal and far lateral root compression. However, in cases of double herniation, total facetectomy is preferable.

[Transsacral approach to lumbosacral extraforaminal disc herniations]

INTRODUCTION

The lateral approach is classically used for surgical treatment of extraforminal disc herniations (EDH). However, its use at the level of the L5-S1 space can require more or less extensive resection of the facet joint. This study reports our experience in the treatment of L5-S1 EDH using the transsacral approach described by Muller and Reulen in 1998.

MATERIAL AND METHODS

From February 2002 to October 2004, 12 patients presenting EDH at the L5-S1 level underwent treatment using the transsacral approach. There were 8 men and 4 women. Mean age was 55 years (range: 36 to 75 years). All patients presented lumbalgia and L5radiculalgia. Only one patient had dysesthesia. Five patients presented motor deficits and 3 presented sensory deficits. Surgical treatment was proposed after failure of medical treatment and two L5 corticoids infiltrations.

RESULTS

All patients were re-examined two months after the procedure. Mean follow-up was 15 months. Complete resolution of radiculalgia with no paresthesia was achieved in all patients. Patients presenting preoperative motor deficit recovered fully after treatment. All patients resumed normal activity.

CONCLUSION

The transsacral approach is a valid alternative to the lateral approach for treatment of L5-S1 EDH. The amount of operative exposure achieved using this technique is sufficient to avoid joint injury that can result in chronic postoperative lumbalgia. Another advantage is that excision of the protruding disc fragment can be achieved without mobilization of the nerve root or dorsal root ganglion, thus avoiding postoperative dysesthesia.

Nucleus pulposus-induced apoptosis in dorsal root ganglion following experimental disc herniation in rats

STUDY DESIGN

The mechanisms behind the formation of a characteristic tissue reaction at the surface of the dorsal root ganglion (DRG) exposed to nucleus pulposus was studied with special reference to apoptosis using electron microscopy and immunohistochemistry in rats.

OBJECTIVES

To study the mechanism of the characteristic tissue reaction at the surface of the DRG exposed to nucleus pulposus.

SUMMARY OF BACKGROUND DATA

Recently, it was observed that local application of nucleus pulposus may induce a characteristic tissue reaction at the surface of the DRG. This change occurred as early as 1 day after the application of nucleus pulposus. METHODS.: Herniation of nucleus pulposus was created in the L4-L5 disc in rats. The L4 DRG were resected 3 and 24 hours after surgery. The sections of the specimens were observed using light and electron microscopy. The sections were processed for immunohistochemistry using antibodies to single-stranded DNA (ssDNA), caspase 3, and tumor necrosis factor alpha (TNF).

RESULTS

There were typical changes of the cell nuclei observed by light and electron microscopy, especially those of the small-sized cells, in the DRG 24 hours after application of nucleus pulposus, indicating the presence of apoptosis. The presence of ssDNA, caspase 3, and TNF further enhanced the impression that there was apoptosis in the DRG. Nucleus pulposus induced apoptosis in the DRG at the site of application within as little as 24 hours.

CONCLUSIONS

Nucleus pulposus herniated from the disc induced apoptosis in at the surface of the DRG exposed to nucleus pulpous as early as 24 hours after exposure.

Lumbar disc herniations: surgical versus nonsurgical treatment

Lumbar disc herniation is among the most common causes of lower-back pain and sciatica. The cause(s) of lumbar disc herniation and the relation of lumbar disc herniation to back pain and sciatica have not been fully elucidated, but most likely comprise a complex combination of mechanical and biologic processes. Furthermore, the natural history of lumbar disc herniation seems generally to be favorable, leaving the optimum treatment for lumbar disc herniation a debate in the literature. Various nonoperative and operative treatment strategies have been tried with varying degrees of success. Treatment often involves patient education, physical therapy, alternative medicine options, and pharmaco-therapy. If these fail, surgical intervention is usually recommended. A literature search was conducted to evaluate the currently known effectiveness of traditional and novel non-operative and surgical techniques for the treatment lumbar disc herniation and to determine if there are substantive new advantages in these newer contemporary treatments or combinations thereof. A structured approach to treatment of a patient who may have a symptomatic lumbar disc herniation is presented, based on analysis of the current literature. No one method of nonoperative or operative treatment would seem definitively to be superior to another. Appropriate multidisciplinary treatment including behavioral analysis and support may offer the hope of improved outcomes for patients with lumbar disc herniation.

LEVEL OF EVIDENCE

Level V (expert opinion). See the Guidelines for Authors for a complete description of the levels of evidence.

Micro-endoscopic-discectomy (MED) for far lateral disc herniation in the lumbar spine. Technical note

This study describes a new experience of the authors in the treatment of extraforaminal disc herniation via the micro-endoscopic far lateral approach to establish a less traumatic approach to extraforaminal disc herniation with less stay in hospital and less cost. Seventeen patients who underwent surgery for extraforaminal disc herniation were analysed and long-term follow up was done revisiting all of them in hospital. The results of surgical decompression via the micro-endoscopic far lateral approach were good in all patients with minimal discomfort. There was complete resolution of leg pain presented. Dysesthesia subsided after 2-3 weeks. Extraforaminal disc herniation can be diagnosed with the aid of CT scan and MRI. The minimally invasive surgical treatment via the micro-endoscopic far lateral approach, in our initial experience, has a high rate of succes.

Distribution and appearance of tumor necrosis factor-alpha in the dorsal root ganglion exposed to experimental disc herniation in rats

STUDY DESIGN

Distribution and appearance of tumor necrosis factor-alpha (TNF-alpha) in the dorsal root ganglion (DRG) exposed to experimental disc herniation were investigated using an immunohistochemical method in rats.

OBJECTIVES

To study the distribution and appearance of TNF-alpha in the DRG following experimental disc herniation in rats.

SUMMARY OF BACKGROUND DATA

Nucleus pulposus in the epidural space induces spinal nerve root injury not only by mechanical but also chemical mechanisms. Cytokines may play a key role in the chemical damage. There is, however, no report on the distribution and appearance of TNF-alpha in the DRG exposed to nucleus pulposus.

METHODS

Nucleus pulposus from the discs was smeared on the glass slides and processed for immunohistochemistry by the avidin-biotinylated peroxidase complex technique using rabbit antisera to TNF-alpha in rats. A herniation of the nucleus pulposus was made by incision of the L4-L5 disc in rats. The L4 and L5 DRGs were resected 1, 3, 7, 14, and 21 days after surgery. The specimens were processed for immunohistochemistry using rabbit antisera to TNF-alpha. The TNF-alpha-positive cells were observed and counted using light microscopy. Distribution of the TNF-alpha products was compared on each day after surgery.

RESULTS

A positive staining was seen in the cell bodies and in the matrix between the cells in the smeared nucleus pulposus. In the L4 DRG sections, the number of positive cells was significantly higher in the disc incision group than in the sham group at 1, 3, 7, and 14 days after surgery (P < 0.05). The positive cells showed a decrease in number day by day after surgery. On the contrary, in the L5 DRG, only a few positive cells were observed in the disc incision group after surgery. There was no statistically significant difference between disc incision and the sham groups at each day after surgery for the L5 DRGs.

CONCLUSIONS

The immunoreactivity of TNF-alpha in the DRG directly exposed to nucleus pulposus increases during 2 weeks. A collapse of the positive cells was seen in the DRG directly exposed to the nucleus pulposus.

Extraforaminal Lumbar Herniation

The first anatomic description of extraforaminal herniation found in the literature was published in 1944. This was followed by several definitions regarding the anatomic site of this pathology. We consider correct the definition of lumbar extraforaminal herniation concerning the anatomic site of the herniated fragment. This fragment compresses the nervous root after its exit from the foramen, thus causing the compression of the spinal ganglion against the strong intertransverse ligament. The incidence of the pathology shifts from 1% to 12% and in our study was 4.2%. Over these years, the surgical approach has changed mainly because of two requirements: good exposition both of the foramen and of the herniation and the necessity of preserving stability of the spinal column as much as possible. In the last 30 years, less invasive approaches, paramedian, para- and transmuscular, lateral, and tangential, have been preferred to an interlaminar medial approach with a subtotal and/or complete facetectomy. In the last 4 years, 46 patients presenting with pure extraforaminal herniation have been treated in our institute through a far lateral microsurgical approach, avoiding resection of bone and reducing to the minimum the muscular retraction and the closure of blood vessels. We advocate a far lateral microsurgical approach, with no resection of bone and with highest respect for the osseous articular and muscular structures.