Percutaneous Transpedicular Lumbar Endoscopy: A Case Report

Full Endoscopic Transpedicular Discectomy for a Rostrally Migrated L5-S1 Disc Herniation in the Setting of Previous Lumbar Surgery: A Case Report With Intraoperative Video

BACKGROUND AND IMPORTANCE

The surgical management of rostral disc herniations at L5-S1 poses challenges for conventional endoscopic approaches, particularly in patients who have had previous lumbar surgery. We present a full endoscopic transpedicular discectomy (FETD), whereby a pediculotomy is created to pass an endoscope through the pedicle for intracanal access. This addresses anatomic obstacles and potential complications associated with other endoscopic and minimally invasive or open techniques. To date, this is the only article to highlight this approach with a case report and intraoperative video.

CLINICAL PRESENTATION

A 76-year-old man with a history of L3-S1 laminectomy presented with left leg pain and a near-complete left foot drop. An MRI revealed a left paracentral rostrally migrated disc herniation arising from L5-S1 with impingement of the exiting left L5 nerve root at the inferomedial aspect of the pedicle of L5. The patient consented to the FETD procedure. Using sequential reamers of increasing diameter and a high-speed burr, a superolateral to inferomedial pediculotomy was performed. This approach allowed us to target the pathology at the point of maximum compression without traversing the prior operative field. A transforaminal endoscopic approach was not possible with the iliac crest obstructing rostral angulation. The disc was successfully removed without any intraoperative complications, and after surgery, the patient's radiculopathy resolved without any radiographic evidence of instability.

CONCLUSION

FETD is a unique approach that demonstrates the versatility of endoscopic spine surgery, offering advantages over conventional approaches particularly for rostral disc herniations at L5-S1 in the setting of prior lumbar surgery.

The Biomechanics of the Transpedicular Endoscopic Approach

STUDY DESIGN

Biomechanical cadaveric study.

OBJECTIVE

The goal of this study was to analyze the effects of an endoscopic transpedicular approach with different drill diameters (6 and 8 mm) and compare them with the intact native side. In addition, the influence of bone quality on the resistance of the pedicle was investigated.

SUMMARY OF BACKGROUND DATA

Clinical studies have repeatedly highlighted the benefits of endoscopic transpedicular decompression for downmigrated lumbar disc herniations. However, the biomechanical effects on pedicle stability have not been studied up to now.

MATERIALS AND METHODS

Twenty-four vertebras originating from four fresh-frozen cadavers were tested under uniaxial compression load in a ramp-to-failure test: (1) the tunneled pedicle on one side, and (2) the native pedicle on the other side. Twelve lumbar vertebrae were assigned to drill diameter of 6 mm and the other 12 to diameter of 8 mm.

RESULTS

The median ratio of sustained force for the operated side compared with the intact contralateral side is equal to 74% (63-88) for both drill diameters combined. An 8 mm transpedicular approach recorded an axial resistance of 77% (60-88) compared with the intact contralateral side ( P =0.002). A 6 mm approach resulted in an axial resistance of 72% (66-84) compared with the intact opposite side ( P =0.01). No significant difference between the two different drill diameters was recorded ( P =1). For all three subgroups (intact, 8 mm, 6 mm) the Hounsfield units-values and the absolute resistance force showed significant correlations (intact: ρ=0.859; P <0.001; 8 mm: ρ=0.902; P <0.001; 6 mm: ρ=0.835; P <0.001).

CONCLUSION

The transpedicular approach significantly reduces the axial resistance force of the pedicle, which may lead to pedicle fracture. Bone quality correlated positively with the absolute resistance force of the pedicle, whereas the influence of the drill hole diameter plays only a limited role.

Full Endoscopic Transpedicular Technique in the Treatment of High Grade Down Migrated Herniated Disc: An Evaluation of Clinical Outcomes at 12 Months Follow-Up

OBJECTIVE

High-grade migrated lumbar disc herniation (LDH) such as up-migrated and down-migrated discs are challenging pathologies to treat. High-grade migrated discs are usually sequestered and situated adjacent to the medial pedicle wall. This can be easily addressed if the pedicle is used as an access route. The authors present a retrospective case series of high-grade migrated LDH treated using a full endoscopic transforaminal approach.

MATERIALS AND METHODS

This is a retrospective case series. The clinical outcomes in the patients were evaluated according to improvement in the symptoms as suggested by improvement in Visual Analog Score (VAS) and Oswestry Disability Index (ODI) scores in the immediate postoperative period and at the final follow-up. The radiological outcomes were evaluated using postoperative magnetic resonance imaging and computed tomography scans. After the data were collected and tabulated, descriptive statistics were used for continuous variables. The t test was used to determine the significance of changes in the VAS and ODI scores. Statistical significance was set at P < 0.05.

RESULTS

Five patients underwent discectomy using the transpedicular technique, and the mean preoperative VAS scores for the back and leg were 7.2 ± 0.83 and 8.4 ± 0.54, respectively. The mean VAS scores at the final follow-up for the back was 0.2 ± 0.4 and 0 for the leg (P < 0.05). The mean preoperative ODI score was 72 ± 8.3, which improved to 6 ± 4.69 at the final follow-up (P < 0.05). All patients had a hospital stay of 1 day.

CONCLUSIONS

The full endoscopic transpedicular approach is a good option for treating highly migrated LDH. Surgical planning, including pedicle morphometry and the angle of the approach, should be undertaken preoperatively for the best results.

A Novel Trajectory for a Transpedicular Approach in the Treatment of a Highly Downward-Migrated Lumbar Herniation with a Full Endoscopic Technique

Background

To evaluate the clinical outcome of full endoscopic discectomy using a novel trajectory via a transpedicular approach.

Method

Thirty-five patients were enrolled in this retrospective study between July 2014 and October 2019 in the Beijing Haidian Hospital. All patients were treated with full-endoscopic lumbar discectomy via a transpedicular approach with an oblique trajectory. The imaging parameters, including pedicle height and angle of trajectory, were recorded. The preoperative and postoperative clinical data were collected for statistical analysis.

Results

All patients underwent successful surgery without severe complications. We compared the visual analogue scale and Oswestry disability index scores before and after surgery. The differences were statistically significant (p < 0.05). According to the modified Macnab criteria, the good-to-excellent rate was 85.7% at the last follow-up. The average angles of trajectory in the sagittal and coronal planes were 34.5° ± 2.9° and 47.1° ± 5.0°, respectively.

Conclusion

The new trajectory of the transpedicular approach with a full endoscopic technique for an extremely downward-migrated disc herniation showed excellent results in a small sample study. A precise surgical plan is required, comprising measurements of the pedicle height and angle of the bone tunnel.

[Two treatment approaches for lumbar disc herniation and sequester migration to the second and third McCulloch's windows: transpedicular and translaminar sequestrectomy (ridit analysis)]

A ridit analysis of results of transpedicular endoscopic and translaminar microsurgical surgeries for sequester migration to the second and third McCulloch's windows was carried out. The authors assessed pain syndrome, quality of life and neurological impairment.

OBJECTIVE

To compare the outcomes of transpedicular and translaminar sequestrectomy for lumbar disc herniation and sequester migration to the second and third McCulloch's windows.

MATERIAL AND METHODS

We analyzed treatment outcomes in 51 patients with lumbar disc herniation and severe sequester migration. We assessed lumbar and leg pain syndrome using then visual analogue scale, neurological impairment using the adapted Nurik scale and quality of life using the Oswestry questionnaire and the MacNab scale in early postoperative period, as well as in 2 weeks, 6 and 12 months after surgery. Ridit analysis was used for statistical processing of data.

RESULTS

Transpedicular sequestrectomy was performed in 24 patients, translaminar sequestrectomy - in 27 cases. Groups were comparable by gender, size and location of sequestration, somatic and neurological status, as well as pain severity. There was a higher probability of back (0.39) and leg (0.364) pain regression, neurological recovery (0.446) and improvement of quality of life according to the Oswestry questionnaire (0.389) after transpedicular surgery. According to the MacNab scoring system, excellent and good results were obtained in 84.21% and 15.79% of patients in 6 months after transpedicular surgery. In the second group, excellent, good and satisfactory results were obtained in 63%, 25.9% and 11.1% of patients, respectively.

CONCLUSION

Herniated intervertebral discs with severe sequester migration should be divided in accordance with localization of the main sequestration. Transpedicular endoscopic approach is advisable for sequester in the third and rarely the second McCulloch's windows. Translaminar microsurgical approach is preferred for sequestration in the second and rarely the third McCulloch's windows. Clinical outcomes after translaminar microsurgical sequestrectomy and transpedicular endoscopic surgeries are similar. However, postoperative back and leg pain regression, neurological recovery and improvement of quality of life according to the Oswestry scoring system are more common after transpedicular surgery.

[Comparison of transpedicular endoscopic sequestrectomy and discectomy in the treatment of lumbar intervertebral disc herniation with a high degree of migration]

BACKGROUND

Surgical treatment of intervertebral disc herniation with a high degree of migration (beyond the vertebral pedicle) is a difficult problem without an unambiguous solution. In this manuscript, we compare the effectiveness of transpedicular endoscopy and standard discectomy in the treatment of patients with this disease.

OBJECTIVE

To compare transpedicular endoscopic sequestrectomy and discectomy in the treatment of lumbar intervertebral disc herniation with a high degree of migration.

MATERIAL AND METHODS

There were 28 patients divided into 2 groups: group 1 - 13 patients after transpedicular endoscopic sequestrectomy, group 2 - 15 patients after discectomy.

RESULTS

Transpedicular endoscopic sequestrectomy ensured significantly better intraoperative parameters (incision length, blood loss, surgery time) (p<0.01). In both groups, postoperative VAS score of leg pain was significantly reduced within a day after surgery from 7.4±1.3 to 0.7±0.7 and from 7.1±1 to 0.8±0.5, respectively. In the 1^st group, VAS score of back pain regressed from 5.2±0.7 to 1.1±0.89 by the end of the 1^st postoperative day. This value was 0.6±0.5 a year later. In the 2^nd group, VAS score of back pain regressed from 4.9±1 to 2.5±0.9 by the end of the 1^st postoperative day. This value was 2.8±2.3 a year later. According to McNab clinical outcome scale, excellent and good results after transpedicular endoscopic sequestrectomy were obtained in all 13 (100%) patients, after discectomy - in 80% of cases.

CONCLUSION

Transpedicular endoscopic sequestrectomy is optimal for intervertebral disc herniation with a high degree of migration due to fast postoperative recovery and no complications.

Transpedicular endoscopic removal of highly migrated disc herniations of lumbar spine

Background. Highly migrated disc herniations are usually localized in the area of pars interarticularis medially to the vertebral pedicle. Removal of disk herniations of this localization is a difficult technical task.

The study objective is to demonstrate the effectiveness of the transpedicular endoscopic discectomy in the treatment of patients with highly migrated disc herniations.

Materials and methods. The results of treatment of 12 patients with Macnab zone herniations who were in hospital from 2016 to 2018 were analyzed. All patients underwent transpedicular endoscopic sequestrectomy.

Results. Leg pain after surgery regressed in all patients from the initial 7.41 points (visual-analog scale) to 0.67 points by the end of the 1st day, and it was 0.35 points a year later. The average level of back pain by VAS before surgery was 5.25, on the 1st day after surgery – 1.25 points, 1 year after – 0.67 points. Neurological disorders completely regressed in 10 (91.6 %) patients, there were a slight residual L4 dermatome hypesthesia in 2 patients, without disrupting their quality of life. The average Oswestry Disability Index before surgery was 69.17, and 1 year after surgery was 14.12. There were no complications and reoperations.

Conclusion. Transpedicular endoscopic discectomy allowed us to achieve good treatment results in patients with migration of a lumbar hernia by the pedicle. It can be a safe and effective alternative to the transforaminal or interlaminar endoscopic technique.

Current and Future of Endoscopic Spine Surgery: What are the Common Procedures we Have Now and What Lies Ahead?

The aging population around the world leads to increasing incidence of degenerative spinal conditions. There is a need for a minimally invasive technique in treatment for spinal conditions to meet the medical complexity and comorbidities that comes with aging. Principles of endoscopy are similar to minimally invasive surgery, which is to decrease pressure on soft tissue crushing from prolonged retraction, avoid soft tissue stripping and dissection, and bone and ligamentous preservation for optimal decompression without excessive destruction. Endoscopic spine surgery techniques started slowly in development in the 1970s to 2000s, with a rapid phase of development since the turn of the 21st century with endoscopic solutions developing in cervical, thoracic, and lumbar conditions with increasing complexity in nature of operation. Technological enhancement with progressively supportive literature is pushing boundaries of endoscopy from the early days of soft tissue procedure to current fusion procedures, endoscopic spine surgery techniques is covering more areas of spine than ever previously possible with good clinical results. We present a review on the current techniques available and postulated near future development for endoscopic spine surgery.

Suprapedicular Retrocorporeal Technique of Transforaminal Full-Endoscopic Lumbar Discectomy for Highly Downward-Migrated Disc Herniation

OBJECTIVE

Anatomical barriers (e.g., pedicles, narrow foramina) can hinder direct access to, and removal of, disc fragments that have migrated far downward. Using transforaminal full-endoscopic lumbar discectomy (FELD), we devised a modified technique, the suprapedicular retrocorporeal approach, for herniations in which the disc has migrated to the axilla of the traversing nerve roots. In the present report, we have described our preliminary results.

METHODS

Soft, highly downward-migrated disc herniation was treated with transforaminal FELD through the suprapedicular retrocorporeal approach in 22 patients from June 2017 to May 2019. The clinical outcomes were evaluated, including the preoperative and postoperative visual analog scale scores for the back and leg, Oswestry disability index, and MacNab criteria for surgical success.

RESULTS

The affected discs were at L4-L5 in 14 patients, L3-L4 in 6 patients, and L5-S1 in 2 patients. In each case, the affected disc was successfully removed using the suprapedicular retrocorporeal approach. The mean follow-up was 18.1 ± 5.7 months. The mean visual analog scale scores for back and leg pain improved significantly (P < 0.05 for both). The mean Oswestry disability index had decreased from 62.5 ± 14.2 preoperatively to 10.5 ± 5.9 postoperatively (P < 0.05). Using the MacNab criteria, 13 patients reported excellent outcomes and 9, good outcomes. No complications or recurrence developed during follow-up.

CONCLUSIONS

The suprapedicular retrocorporeal technique is a feasible and effective surgical option in transforaminal FELD for the treatment of herniation in which the disc has migrated to the axilla of the traversing nerve roots.

Transforaminal Endoscopic Surgery: Outside-In Technique

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

A Narrative Review of Development of Full-Endoscopic Lumbar Spine Surgery

In the first phase of development of lumbar endoscopic spine surgery, the focus was on removal of soft disc material through the working corridor of Kambin’s triangle using transforaminal endoscopic lumbar discectomy. With the introduction of the interlaminar approach and increased interest from both industry and surgeons, there has been an exponential development of endoscopic surgical equipment and a corresponding expansion of endoscopic techniques. Endoscopic treatment strategies are applied to conditions ranging from contained prolapsed intervertebral discs to noncontained migrated herniated discs, hard calcified discs, spinal stenosis in the central or lateral recess and the foraminal and extraforaminal region, and other combinations of degenerative conditions requiring decompression or fusion surgery. The further expansion of endoscopic surgical management involving complicated spinal cases and the final quartet of trauma, infections, tumors, and possibly deformities could be the future stage of endoscopic spine surgery development. This article covers the full range of current treatment strategies and presents possible future developments of endoscopic spine surgery for the management of lumbar spinal conditions.

Full-endoscopic transpedicular discectomy (FETD) for lumbar herniations: Case report and review of the literature

INTRODUCTION

One of the most challenging occurrences in full-endoscopic surgery for lumbar disc protrusions are up-migrated or down-migrated herniations. Those occurrences are difficult to retrieve with transforaminal or interlaminar approaches.

PRESENTATION OF CASE

We describe our experience in dealing with a right paramedian down-migrated L3-L4 disc herniation. The patient underwent full endoscopic transpedicular endoscopic discectomy (FETD), by reaming the right L4 peduncle for intracanal access and fragment retrieval. We also reviewed the recent literature to summarize the advantages of transpedicular approaches, along with current indications and contraindications for this procedure.

DISCUSSION

We highlighted how FETD is safe and feasible for down-migrated and up-migrated disc herniation showing excellent results in our patient and in the small cohorts of patients already published in the literature.

CONCLUSION

FETD was effective in treating up-migrated and down-migrated disc herniation, as well as discal cysts, showing the feasibility and safety of the technique from any level from L1 to S1.

Transpedicular Endoscopic Surgery for Highly Downmigrated L5-S1 Disc Herniation

Endoscopic surgery for highly downmigrated disc herniation at level L5-S1 is a challenging technique. Most surgeons prefer the interlaminar access because of the special anatomy of the L5-S1 disc level, i.e., narrow neuroforamen and large interlaminar window. Transforaminal access to the neuroforamen L5-S1 is difficult in cases with high iliac crest. Here, the access to the highly downmigrated disc herniation with the recently reported technique of transpedicular endoscopic surgery by Krzok et al. was described. In 3 cases with highly downmigrated disc herniation of L5-S1, the sequester was removed successfully through the bone hole of S1 pedicle. This technique is demanding for experienced endoscopic surgeons.

Percutaneous endoscopic transpedicular approach for high-grade down-migrated lumbar disc herniations

BACKGROUND

Surgical options for removing high-grade down-migrated lumbar disc herniations located medial to the pedicle include an extensive laminectomy and facetectomy. A direct percutaneous endoscopic approach through the pedicle for reaching the herniated disc without risk of iatrogenic instability is feasible.

METHOD

The transpedicular approach consists of creating a tunnel through the pedicle. Subsequently, access to the parapedicular epidural space is obtained, and downward migrated disc can be removed.

CONCLUSION

This technique allows to reach migrated herniations medially to the pedicle safely and effectively.