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

Full Endoscopic Lumbar Foraminoplasty with Periendoscopic Visualized Trephine Technique for Lumbar Disc Herniation with Migration and/or Foraminal or Lateral Recess Stenosis

PURPOSE

To introduce a newly designed periendoscopic visualized trephine system for foraminoplasty in treating lumbar disc herniation with migration and/or foraminal or lateral recess stenosis, and report early clinical outcomes evaluated by the Patient-Reported Outcomes Measurement Information System (PROMIS).

METHODS

A total of 25 patients who underwent transforaminal endoscopic lumbar discectomy with foraminoplasty using a periendoscopic visualized trephine from June 2019 to January 2020 were retrospectively reviewed. PROMIS pain interference and physical function were selected as outcome measures.

RESULTS

The average age of the 25 patients (16 males, 9 females) was 32.0 ± 7.5 years (20-48 years). All patients were successfully followed up with the mean time of 10.1 ± 2.8 months (6-12 months). PROMIS pain interference scores decreased significantly from mean 67.0 ± 3.4 preoperatively to 37.5 ± 5.4 at the final follow-up (P < 0.01), and PROMIS physical function scores improved significantly from mean 29.2 ± 5.5 preoperatively to 59.3 ± 3.7 at the final follow-up (P < 0.01). No neural or vascular complication occurred.

CONCLUSION

Full endoscopic lumbar foraminoplasty with a periendoscopic visualized trephine technique is safe and effective for treating lumbar disc herniation with migration and/or lateral recess or foraminal stenosis, with improved flexibility and convenience and decreased radiation exposure.

Full-Endoscopic Foraminotomy with a Novel Large Endoscopic Trephine for Severe Degenerative Lumbar Foraminal Stenosis at L5 S1 Level: An Advanced Surgical Technique

To (i) introduce the technical notes of a novel full‐endoscopic foraminotomy with a large endoscopic trephine for the treatment of severe degenerative lumbar foraminal stenosis at L₅S₁ level; (ii) assess the primary clinical outcomes of this technique; (iii) compare the effectiveness of this full‐endoscopic foraminotomy technique and other previous techniques for lumbar foraminal stenosis. From January 2019 to August 2019, a retrospective study of L₅S₁ severe degenerative lumbar foraminal stenosis was performed in our center. All patients who were diagnosed with severe foraminal stenosis at L₅S₁ level and failed conservative treatment for at least 6 weeks were identified. Patients with segmental instability or other coexisting contraindications were excluded. A total of 21 patients were enrolled in the study. All patients were treated by full‐endoscopic foraminotomy using large endoscopic trephine. The visual analogue scale (VAS) and Oswestry disability index (ODI) were evaluated preoperatively and at 1, 3, 6 months, and 1 year after the surgery, and the modified MacNab criteria were used to evaluate clinical outcomes at the last follow‐up. There were 10 males and 11 females with a mean age of 66.38 ± 9.51 years. Five patients had a history of lumbar surgery. The mean operative time was 63.57 ± 25.74 min. The mean follow‐up time was 13.29 ± 1.38 months. The mean postoperative hospital stay time was 1.29 ± 0.56 days. The mean preoperative VAS score significantly decreased from 7.38 ± 1.02 to 2.76 ± 1.09 (t = 19.759, P < 0.01), 2.25 ± 1.02 (t = 21.508, P < 0.01), 1.60 ± 1.05 (t = 31.812, P < 0.01), and 1.45 ± 1.10 (t = 25.156, P < 0.01) at 1 month, 3 months, 6 months, and 1 year after the operation. The mean preoperative ODI score significantly decreased from 64.66% ± 4.91% to 30.69% ± 4.59% (t = 33.724, P < 0.01), 29.44% ± 4.50% (t = 32.117, P < 0.01), 24.22% ± 4.14% (t = 33.951, P < 0.01), and 22.44% ± 4.94% (t = 30.241, P < 0.01) at 1 month, 3 months, 6 months, and 1 year after the operation. At the last follow‐up, 19 patients (90.48%) got excellent or good outcomes. One patient suffered postoperative dysesthesia, and the symptoms were controlled by conversion treatment. One patient took revision surgery due to the incomplete decompression. There were no other major complications. Percutaneous endoscopic decompression is minimally invasive spine surgery. However, the application of endoscopic decompression for L₅S₁ foraminal stenosis is relatively difficult due to the high iliac crest and narrow foramen. Full‐endoscopic foraminotomy with the large endoscopic trephine is an effective and safe technique for the treatment of degenerative lumbar foraminal stenosis.

Clinical outcomes of transforaminal endoscopic lateral recess decompression by using the visualized drilled foraminoplasty and visualized reamed foraminoplasty: a comparison study

Background

Lateral recess stenosis (LRS) is a common degenerative disease in the elderly. Since the rise of comorbidity is associated with increasing age, transforaminal endoscopic lateral recess decompression (TE-LRD) is advocated. The objective of this study was to compare the clinical outcomes of TE-LRD in patients with LRS via visualized drilled foraminoplasty (VDF) or visualized reamed foraminoplasty (VRF) technique.

Methods

A total of 45 and 42 consecutive patients with limp or unilateral radiculopathy symptoms underwent TE-LRD using the VDF and VRF technique, respectively. The radiation exposure and operation time, time to return to work, and complications were compared between two groups. Their clinical outcomes were evaluated with the visual analogue scale (VAS) leg pain score, VAS back pain score, Oswestry Disability Index (ODI) and modified MacNab’s criteria.

Results

The average values of radiation exposure and operative time in the VDF group were significantly higher than those in the VRF group (P <  0.05). The postoperative VAS and ODI scores in both groups were significantly improved compared with those before the operation (P <  0.05). In addition, the VAS score of the leg pain and ODI score in the VRF group were significantly lower than those in the VDF group at the 1-week follow-up (P <  0.05). The good-to-excellent rates of the VDF group and VRF group were 88.89 and 90.48%, respectively, whereas the complication occurrence rates were 6.67 and 4.76% in the VDF group and VRF group, respectively.

Conclusions

TE-LRD performed by using VRF technique can be applied to treat LRS safely and effectively with short radiation exposure and operation time. This technique was comparable to the VDF technique with improved VAS leg pain and ODI scores in the short period after the operation. However, potential complications and risks still need to be considered.

Safety Evaluation of Biportal Endoscopic Lumbar Discectomy: Assessment of Cervical Epidural Pressure During Surgery

STUDY DESIGN

A prospective study.

OBJECTIVE

To evaluate the change in cervical epidural pressure (CEP) during biportal endoscopic lumbar discectomy (BELD).

SUMMARY OF BACKGROUND DATA

In percutaneous uniportal endoscopic lumbar discectomy, irrigation fluid (IF) introduced into the spinal canal during surgery can compress the thecal sac, and act as a potential risk for neurological complications by disturbing cerebrospinal fluid (CSF) circulation and increasing intracranial pressure.

METHODS

Thirty consecutive patients, who underwent BELD, which was performed under automated pump system, an infusion pressure of 30 mmHg were enrolled. The change in CEP on C7-T1 level was measured. CEP was measured in each of the five phases of the procedure (1st phase-making surgical portals; 2nd phase-creating a workspace; 3rd phase-performing neural decompression and discectomy; 4th phase-factitious increase of pressure by clogging the outflow; 5th phase-dismission from fluid irrigation system). Neurological complications and independent risk factors were evaluated.

RESULTS

In the final 27 patients, changes in CEP during surgery were similar. The baseline CEP was 14.8 ± 2.8 mmHg, and the mean CEP in the 3rd phase 18.8 ± 5.1 mmHg was not significantly higher. In the 4th phase, however, the CEPs rose with linear correlation as the pressure increased. In the 5th phase, the elevated CEP returned to baseline in 2.5 ± 5.6 minutes. No patient had neurological complications. No statistically significant risk factors were observed.

CONCLUSION

In BELD, which is performed to allow continuous lavage with infusion pressure set to 30 mmHg, CEP does not increase beyond the physiological range. Therefore, BELD may be considered as a potentially safe technique.

LEVEL OF EVIDENCE

4.

Comparative Effectiveness Between Primary and Revision Foraminotomy for the Treatment of Lumbar Foraminal Stenosis

BACKGROUND

Foraminotomy has demonstrated clinical benefit in patients with lumbar foraminal stenosis (LFS), as evidenced by several small retrospective investigations. However, there is a subset of patients who have recurrent symptoms following the operation and therefore require revision surgery. Yet, despite this phenomenon, the relative efficacy of revision foraminotomy (RF) is not well elucidated due to limited literature on the quality of life (QOL) outcomes and cost associated with primary foraminotomy (PF) and RF.

PURPOSE

To compare the effectiveness of PF and RF in terms of QOL outcomes and relative costs.

STUDY DESIGN/SETTING

This is a retrospective cohort study conducted at a single tertiary-care institution. The patient sample consisted of patients undergoing foraminotomy for the treatment of LFS between 2008 and 2016. The primary outcome measure was improvement in postoperative QOL, as measured by EuroQol 5-Dimensions (EQ-5D), and secondary outcome measures included Pain Disability Questionnaire (PDQ) and Patient Health Questionnaire-9 (PHQ-9) perioperative cost as well as minimum clinically important difference (MCID).

METHODS

A retrospective chart review was conducted to identify individuals who underwent PF or RF for LFS and to collect clinical, operative, and demographic data. QOL scores (EQ-5D, PDQ, and PHQ-9) were collected between 2008 and 2016, and perioperative financial data were extracted via the institution's cost utilization engine. Paired t tests were used to assess changes within treatment groups, and Fisher exact tests were used for intercohort comparisons.

RESULTS

Five hundred seventy-nine procedures were eligible: 476 (82%) PF and 103 (18%) RF. A significantly higher proportion of males underwent RF than PF (71% versus 59%, P = .03), and PF was done on a significantly higher number of vertebral levels (2.2 versus 2.0, P = .04). There were no other significant differences in demographics. Preoperatively, mean PDQ-Functional scores (50 versus 54, P = .04) demonstrated significantly poorer QOL in the RF cohort. Postoperatively, EQ-5D index showed significant improvement in both the PF (0.547→0.648, P < .0001) and the RF (0.507→0.648, P < .0001) cohorts. Similarly, total PHQ-9 improved significantly in the PF cohort (7.84→5.91, P < .001) and in the RF cohort (8.55→5.53, P = .02), as did total PDQ (PF: 77→63, P < .0001; RF: 85→70, P = .04). QOL scores were also compared between groups preoperatively and postoperatively, and the only significant difference between PF and RF was observed in the preoperative PDQ-Functional score (49.7 versus 54.3, P = .04). The proportion of patients achieving MCID was not significantly associated with cohort. Finally, perioperative cost did not differ significantly between cohorts (PF: $13,383 versus RF: $13,595, P = .82).

CONCLUSIONS

Both PF and RF produced significant improvement in nearly all measures in patients with LFS. There was no significant difference in cost between PF and RF, but both PF and RF showed postoperative QOL improvements as compared with preoperative scores, indicating that RF remains a reasonable treatment option for patients with recurrent symptoms of LFS.

Combined Effects of Graded Foraminotomy and Annular Defect on Biomechanics after Percutaneous Endoscopic Lumbar Decompression: A Finite Element Study

Percutaneous endoscopic technology has been widely used in the treatment of lumbar disc stenosis and herniation. However, the quantitative influence of percutaneous endoscopic lumbar decompression on spinal biomechanics of the L5–S1 lumbosacral segment remains poorly understood. Hence, the objective of this study is to investigate the combined effects on the biomechanics of different grades of foraminotomy and annular defect for the L5–S1 segment. A 3D, nonlinear, detailed finite element model of L4–S1 was established and validated. Changes in biomechanical responses upon stimulation to the intact spine during different degrees of resection were analyzed. Measurements included intervertebral rotation, intradiscal pressure, and the strain of disc structure under flexion, extension, left/right lateral bending, and left/right axial rotation under pure bending moments and physiological loads. Compared with the intact model, under prefollower load, annular defect slightly decreased intervertebral rotation by −5.0% in extension and 2.2% in right axial rotation and significantly increased the mean strain of the exposed disc by 237.7% in all loading cases. For right axial rotation, unilateral total foraminotomy with an annular detect increased intervertebral rotation by 29.5% and intradiscal pressure by 57.6% under pure bending moment while the maximum corresponding values were 9.8% and 6.6% when the degree of foraminotomy was below 75%, respectively. These results indicate that percutaneous endoscopic lumbar foraminotomy highly maintains spinal stability, even if the effect of annular detect is taken into account, when the unilateral facet is not totally removed. Patients should avoid excessive extension and axial rotation after surgery on L5–S1. The postoperative open annular defect may substantially increase the risk of recurrent disc herniation.

Necessity of routinely performing foraminoplasty during percutaneous endoscopic transforaminal discectomy (PETD) for lumbar disc herniation

OBJECTIVE

To assess the role of foraminoplasty during percutaneous endoscopic transforaminal discectomy (PETD) and compared the 2-year clinical results of patients underwent PETD w/o foraminoplasty.

METHODS

A total of 412 patients, who underwent PETD at L3-S1 by the same surgical group, were enrolled in this study. The MRI was used to determine the height (H1) and width (W1) of the intervertebral foramen of L3-S1, the distance between the exiting nerve root and the upper edge of the lower vertebral pedicle (H2), and the distance (W2) between the point with 3 mm to the ventral side of the intervertebral space and superior articular process. The intervertebral foramen widths in the flexion (W3) and extension positions (W4) were also measured. A VAS of low back pain (LBP) and leg pain, ODI and JOA scores of LBP were used to assess the clinical results.

RESULTS

Intraoperative verification showed that 347 cases (group A) did not need foraminoplasty, while the other 65 patients (group B) needed foraminoplasty, including 31 at L4-5 and 34 at L5-S1. The H1 and H2 of L3-S1 were reduced gradually without significant difference between two groups. The W1, W2, W3 and W4 were higher in group A (p < 0.05). The W3 was higher than W4 in both groups (p < 0.05). At 2-year follow-up, there was no significant difference of ODI and JOA score between two groups (p > 0.05). The VAS score of LBP was better in group A (p < 0.05).

CONCLUSIONS

Most of PETD procedure at L3-S1 levels could reach the therapeutic target without foraminoplasty. Due to anatomic characteristics of L5-S1, the foraminoplasty rate was much higher at L5-S1.

Biportal endoscopic discectomy for high-grade migrated lumbar disc herniation

OBJECTIVE

Although endoscopic procedures for lumbar disc herniation have improved greatly and offer many advantages, the indications are limited mostly to nonmigrated or low-grade migrated disc herniation. Endoscopic application in migrated disc herniation cases is still challenging and technically demanding. The goal in this study was to determine the feasibility of biportal endoscopic discectomy for removal of high-grade migrated disc herniation.

METHODS

A retrospective review was performed in 262 patients who had undergone biportal endoscopic discectomy after the diagnosis of lumbar herniated disc. According to preoperative MRI findings, disc herniation was classified into 5 zones based on the direction and distance from the disc space. Patients were divided into 2 groups-a high-grade migration group and a low-grade migration group. Clinical outcomes were evaluated using the Oswestry Disability Index (ODI), visual analog scale (VAS), and modified Macnab criteria, and those outcomes and operation time were compared between the 2 groups.

RESULTS

There were 10 patients with "high-grade up," 8 with "low-grade up," 98 with disc-level, 102 with "low-grade down," and 44 with "high-grade down" herniation, thereby yielding 54 patients in the high-grade group and 208 in the low-grade group. Demographic data for the 2 groups showed no significant difference. There was no significant difference between the 2 groups in ODI, VAS, and modified Macnab criteria. Operation time between the 2 groups was not significantly different (60.74 vs 65.63 minutes, p > 0.05).

CONCLUSIONS

Biportal endoscopic discectomy can be effective for high-grade migrated lumbar disc herniation with no prolonged operation time and satisfactory clinical outcomes.

A Historical Review of Endoscopic Spinal Discectomy

As an essential component of minimally invasive spine surgery, endoscopic spine surgery (ESS) has continuously evolved and has been accepted as a practical procedure by the worldwide spine community. Especially for lumbar disc herniation (LDH), the percutaneous endoscopic or full-endoscopic discectomy technique has been scientifically proven through randomized controlled trials and meta-analyses to be a good alternative to open discectomy. The initial concept of endoscopic spine discectomy was concerned with indirect disc decompression using various instruments such as blind forceps, a nucleotome, laser, radiofrequency coblation, and some chemical agents. The main surgical field has been shifted from the intradiscal space to the epidural space. Precise and selective discectomy for extruded LDH in the epidural space under high-quality endoscopic visualization is now feasible. Furthermore, the medical applications of ESS is broadening to include spinal stenosis, segmental instability, infection, and even intradural lesions. In this review article, I describe the history of endoscopic spine discectomy and decompression techniques, as well as evolution of the paradigm. This history may help indicate the future of practical ESS.

Technical Considerations in Endoscopic Lumbar Decompression

With technical development and evolution of endoscopic instruments, endoscopic spinal surgery has become one of the standard treatments for various lumbar spinal diseases ranging from a simple contained disc to complicated cases such as highly migrated disc herniation and other pathology combined with bony degeneration to produce foraminal and canal stenosis. Favorable clinical results of endoscopic decompression for lumbar stenotic disease were reported by several authors. However, studies have also reported limitations, such as steep learning curves and a relatively high complication rate compared with conventional techniques. The endoscopic lumbar decompression technique consists of many essential skills to manage different endoscopic anatomic structures of the spine. From the perspective of surgical completion and safety, this article discusses issues related to technical considerations in endoscopic lumbar decompression.

Percutaneous Transforaminal Endoscopic Removal of Spinal Shrapnel

BACKGROUND

Gunshot injuries are one of the most common causes of the penetrating injuries of the spine. The victims of these injuries usually have neurologic deficits. Percutaneous endoscopic lumbar surgery is one of the most popular surgical spine interventions. We report a case with incomplete radiculopathy due to shrapnel located in L5 foramen that was removed by percutaneous endoscopic technique.

CASE DESCRIPTION

A 23-year-old man sustaining a gunshot injury penetrating to the abdomen presented to our hospital. His first examination revealed a single gunshot wound with entry hole in the left low lumbar region without exit hole and right lower abdominal quadrant tenderness. Plain radiographs and computed tomography showed a bullet in the abdomen and left L5 transverse process fracture and shrapnel in L5 foraminal zone. The bullet was removed by abdominal surgeons without any surgical plan for the shrapnel in the foramen. He was referred to our clinic 3 weeks after discharge. Without any further neurologic deterioration, he had uninterrupted severe pain that was mostly unbearable during the night. Despite gradually increasing dosages of different drugs, his pain relief was insufficient. Percutaneous transforaminal endoscopic removal of the shrapnel was planned.

CONCLUSIONS

Despite the absence of a universally approved algorithm in the treatment of spinal gunshot injuries, endoscopic technique can be kept in mind for a minimal access and invasiveness in case of indication for removal. With experience in endoscopic procedures and familiarity with surgical anatomy, the treatment of this unique case was completed successfully.

Effect of Percutaneous Endoscopic Lumbar Foraminoplasty of Different Facet Joint Portions on Lumbar Biomechanics: A Finite Element Analysis

Objective

To evaluate the influence of percutaneous endoscopic lumbar foraminoplasty of different facet joint portions on segmental range of motion (ROM) and intradiscal pressure (IDP) of L₃/L₄ and L₄/L₅ motion segments by establishing three dimensional finite element (FE) model.

Method

Computed tomography images of a male adult volunteer of appropriate age and in good condition both mentally and physically. Obtained data was used in this study from July 2020 to December 2020, and an intact L_3–5 three dimensional finite element model was successfully constructed using ANSYS and MIMICS software (model M1). The M1 was modified to simulate the foraminoplasty of different facet joint portions, with unilateral cylindrical excision (diameter = 0.75 cm) performed on the tip (model M2) and the base (model M3) of right L₅ superior facet elements along with surrounding capsular ligaments, respectively. Under the same loading conditions, the ROM and IDP of L₃/₄ and L₄/L₅ segments in states of forward flexion, backward extension, left lateral bending, right lateral bending, left axial rotation and right axial rotation were all compared.

Result

Compared with the intact model in backward extension, M2 increased the ROM of L_4/5 segment by 9.4% and IDP by 11.7%, while the ROM and IDP of M3 changed only slightly. In right axial rotation, M2 and M3 increased the ROM of L_4/5 segment by 17.9% and by 3.6%, respectively. In left axial rotation, M2 and M3 increased the ROM of L₄/L₅ segment by 7.14% and 3.6%, respectively. As for other states including forward flexion, left lateral bending, right lateral bending, the ROM and IDP were not significantly distinct between these two models. While focusing on L₃/L₄ segment, obviously changes in the ROM and IDP have not been presented and neither M2 nor M3 changed in any loading condition.

Conclusion

This study provides evidence that the base‐facet foraminoplasty of L₅ superior facet provided a higher segmental stability compared with the tip‐facet foraminoplasty in flexion and axial rotation. Meanwhile, it also shows the two types of foraminoplasty make few differences to the L_4/5 segmental biomechanics. Besides, it does not appear to impact the stability of L₃/L₄ in six states of forward flexion, backward extension, left lateral bending, right lateral bending, left axial rotation and right axial rotation when superior facet of L₅ was partially removed. These findings might be useful in understanding biomechanics of the lumbar spine after foraminoplasty performed on different portions of the facet, thus providing endoscopic surgeons a better reference for operational approach to maintain the function and mobility of the spine.

Bi-needle technique versus transforaminal endoscopic spine system technique for percutaneous endoscopic lumbar discectomy in treating intervertebral disc calcification: a propensity score matched cohort analysis

OBJECTIVE

The aim of this study was to evaluate the clinical results of a Bi-needle technique and conventional transforaminal endoscopic spine system (TESSYS) technique for percutaneous endoscopic lumbar discectomy (PELD) in treating patients with intervertebral disc calcification (IDC).

BACKGROUND

PELD has gained acceptance for treating patients with IDC. The Bi-needle technique was designed to improve the efficiency and safety of PELD.

METHOD

Bi-needle and TESSYS group within each cohort were balanced using 1:1 propensity score matching. Finally, 32 patients with IDC treated by Bi-needle technique from December 2015 to September 2017 were enrolled and 25 patients treated by TESSYS technique from the same spine surgery center between January 2013 and October 2017 were enrolled as controls.

RESULTS

Propensity score matching generated 22 Bi-needle and 22 TESSYS patients. There were no significant differences in visual analog scale and lumbar Japanese Orthopaedic Association scores between Bi-needle and TESSYS group. Operative time and rate of complications in the Bi-needle was significantly better than the TESSYS group (p < 0.01).

CONCLUSIONS

Both surgical methods achieved good clinical outcomes. However, compared with the TESSSY technique, operative time of the Bi-needle technique is shorter, and rate of complications is lower.

A Novel Foraminoplasty Technique for Posterolateral Percutaneous Transforaminal Endoscopic Lumbar Surgery

BACKGROUND

In posterolateral percutaneous transforaminal endoscopic lumbar surgery, foraminoplasty is currently performed by resecting part of the superior articular process together with surrounding soft tissues. This procedure remains technically demanding. An ideal foraminoplasty technique should be safe, easy, efficient, and controllable and should minimize X-ray exposure.

OBJECTIVE

To introduce a novel foraminoplasty technique that is designed in an attempt to obtain the ideal state.

METHODS

The technique is introduced step by step by case illustration. Briefly, the technique is based on the addition of a novel instrument, named a "Foraminoplasty Working Tube," to the commercialized spinal endoscope system. Through the foraminoplasty working tube, the foraminoplasty procedure can be performed under either reduced X-ray guidance or direct endoscopic view.

RESULTS

The technique allows the surgeon to perform an accurate resection of the superior articular process by easily adjusting the foraminoplasty working tube to the target area. To a great extent, the volume of the bone resected is predictable and controllable and just meets the demands of the operation without excessive resection of the superior articular process.

CONCLUSION

The present technique would potentially be a safer, easier, and more efficient foraminoplasty technique.

Biportal endoscopic spine surgery (BESS): considering merits and pitfalls

The biportal endoscopic spine surgery allow us to use conventional spine surgical instruments in the endoscopic procedure like open surgery. And protection of the neural structures with assistant retractor make this procedure safer than the uniportal endoscopic spine surgery. The authors present a novel technique in treating degenerative spinal diseases in variable access angle different from the conventional uniportal endoscopic spine surgeries. The main objective of this report is presenting two approaches for central and extraforaminal stenosis using an assistant retractor. Both central and foraminal stenosis were well decompressed and a migrated disc fragment was removed successfully with this minimal endoscopic procedure without major complications in these cases.

Successful full-endoscopic decompression surgery under local anesthesia for L5 radiculopathy caused by L5-Sforaminal stenosis and L4-5 lateral recess stenosis : A case report

In this report, we presented a 65 year-old male case having right leg pain due to L5 radiculopathy. Based on the radiological examination including CT, MRI and radiculography, double crash impingement of L5 nerve root due to L4-5 lateral recess and L5-S foraminal stenosis was diagnosed. Because of the strong pain, he could not work anymore. His job was a general manager of big hospital, he needed to return to job as soon as possible. We decided to conduct the full-endoscopic decompression surgery of ventral facetectomy (FEVF) for L4-5 lateral recess stenosis and foraminoplasty (FELF) for L5-S foraminal stenosis. The technique can be done under the local anesthesia with only 8 mm skin incision; thus, it must be the least invasive spine surgery. Soon after the surgery, he could return to the original job as a general manager. In conclusion, the full-endoscopic decompression surgery for the spinal canal stenosis such as FELF and FEVF would be minimally invasive procedure and it enable patients the quick return to the original activity. J. Med. Invest. 67 : 192-196, February, 2020.

Sufficient Lumbar Lateral Recess Decompression Acquired by Undercutting "Superior Articular Process Neck" Plus Intervertebral Disk Annuloplasty in Percutaneous Transforaminal Endoscopic Surgery

Background

Percutaneous transforaminal endoscopic surgery has been used as a surgical measure for lumbar lateral recess stenosis. However, the necessary decompressive range has never been clearly documented in detail. Here, we discuss the effectiveness of a percutaneous transforaminal endoscopic procedure with clearly defined decompressive range.

Material/Methods

The relevant data were retrospectively collected from a series of degenerative lateral recess stenosis patients who acquired a prospectively designed percutaneous transforaminal endoscopic procedure in our department. The decompressive procedure mainly included undercutting of superior articular process and intervertebral disk annuloplasty. Leg pain and back pain was evaluated using visual analogue scale (VAS). The functional status was assessed using Oswestry disability index (ODI). The clinical results were also evaluated using MacNab criteria.

Results

From May 2014 to October 2018, a total of 33 patients who met our inclusion criteria were included for analysis. There were no perioperative complications. Leg pain VAS decreased from preoperative score of 6.18±2.38 to final follow-up score of 0.45±1.00 (P<0.01). Back pain VAS decreased from preoperative score of 1.88±2.19 to final follow-up score of 0.64±1.02 (P<0.01). ODI (%) decreased from preoperative score of 47.86±18.15 to final follow-up score of 6.29±6.75 (P<0.01). At the final follow-up, the results of MacNab criteria were excellent in 18 cases (54.55%), good in 14 cases (42.42%), fair in 1 case (3.03%) and poor in 0 cases. None of the patients complained of recurrence of the symptoms during follow-up.

Conclusions

Undercutting of “superior articular process neck” plus intervertebral disk annuloplasty is sufficient for lumbar lateral recess decompression in a transforaminal approach.

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.

Foraminoplasty affects the clinical outcomes of discectomy during percutaneous transforaminal endoscopy: a two-year follow-up retrospective study on 64 patients

Objective: The aim of this study was to assess the significance of how the degree of injury of the facet joint affects clinical outcomes in foraminoplasty.Methods: We retrospectively enrolled 64 patients treated with percutaneous endoscopic transforaminal discectomy with foraminoplasty (PETDF) from January of 2015 to December of 2016. The patients were divided into two groups depending on whether the articular surface of the facet joint was damaged. Preoperative, perioperative, demographic data, and radiographic parameters for these two groups were extracted and compared.Results: There were no significant differences between the two groups in terms of the duration of operation (p = 0.331), intraoperative blood loss volume (p = 0.631), the weight of disc (p = 0.274) or cut bone (p = 0.526). There were no significant differences between the two groups for VAS or ODI at the same time point (p > 0.05). There were significant differences in the VAS scores of low-back pain at 24 h and 24 months after surgery in the injured group. There were significant differences in ISH, ISA, rate of lumbar instability, recurrent herniation, and Macnab scores between the two groups at 24 months after surgery (p < 0.05). The regression equation between ISA and ISH was Y = 4.237 + 0.565x (where Y denotes an increase of ISA; X, reduction of ISH; F = 6.219, p = 0.015). The Poisson ratio was 0.363 (p = 0.003).Conclusions: PETDF is effective and safe for the treatment of lumbar disc herniation. However, when foraminoplasty destroys the articular surface of the facet joint, there may be increases in lumbar instability and recurrence rate post-operation.

Efficacy of percutaneous transforaminal endoscopic decompression treatment for degenerative lumbar spondylolisthesis with spinal stenosis in elderly patients

The efficacy of fusion combined with decompression for the treatment of spinal stenosis with degenerative lumbar spondylolisthesis (DLS) has been debated. Percutaneous transforaminal endoscopic decompression (PTED) under local anesthesia is an ultra-minimally invasive procedure. The present study aimed to evaluate whether PTED is an effective alternative therapy for spinal stenosis associated with DLS in elderly patients. PTED was performed in elderly patients exhibiting lumbar stenosis and low-grade (Meyerding grades I and II) DLS; these patients also exhibited leg-dominant symptoms and had tolerable or absent mechanical back pain. Administration of general anesthesia may be considerably hazardous in patients when combined with comorbid conditions that result from aging. Therefore, the present procedure was performed under local anesthesia. No obvious radiographic lumbar intervertebral instability was identified prior to surgery. Pre- and post-operative visual analogue scale (VAS) score, Oswestry Disability Index (ODI) and walking distance data were collected. The clinical global outcomes following surgery were evaluated using modified MacNab criteria. A total of 18 elderly patients underwent surgery using PTED techniques. The mean follow-up time was 27.7 months (range, 24-33 months) and the mean estimated blood loss was 18.33 ml (range, 10-35 ml). The mean pre-operative ODI, VAS score of the back and VAS score of the leg were 68.2±6.5, 2.8±1.4 and 6.6±1.2, respectively. All average scores improved post-operatively to 31.7±5.2, 1.5±0.6 and 1.7±0.8, respectively, at the latest follow-up. A statistically significant improvement was observed for all scores at 1 month and that the scores remained relatively stable after that. According to modified MacNab criteria, the good-to-excellent rate was 83.3%. Only 1 patient required micro-decompression surgery due to poor rating. The present study indicated that PTED may be an effective alternative therapeutic option for elderly patients with low-grade DLS associated with spinal stenosis. However, PTED techniques continue to evolve and further follow-up studies are required to determine the long-term outcomes of this treatment technique.

Full-Endoscopic Lumbar Foraminoplasty for Symptomatic Cement Leakage with Exiting Nerve Root Impingement

BACKGROUND

Foraminal stenosis, a common disorder occurring in elderly patients, is often caused by narrowing of the foramen, resulting in the confinement of neural structures by the tissue and vertebrae. Full-endoscopic lumbar foraminoplasty (FELF) is an effective treatment option for patients with foraminal stenosis. However, to the best of our knowledge, no previous study has reported the treatment of symptomatic cement leakage. We report a case of symptomatic cement leakage treated with FELF with the patient under local anesthesia.

CASE DESCRIPTION

An 85-year-old woman was admitted to our spine unit because of lower back pain. The patient had presented with lower back pain and new-onset left thigh pain after vertebroplasty performed 3 months previously. The patient was not able to walk and was bedridden. To overcome this problem, T12 percutaneous vertebroplasty and left transforaminal L3-L4 foraminoplasty was performed with the patient under local anesthesia. After surgery, the patient was able to walk and was discharged 4 days postoperatively.

CONCLUSION

The present report has shown that FELF can successfully remove symptomatic cement leakage, resulting in pain relief.

Current techniques of endoscopic decompression in spine surgery

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

Mid-term Clinical Results of Microendoscopic Decompression for Lumbar Foraminal Stenosis

Introduction

There have been several reports on surgical techniques involving microendoscopy or percutaneous endoscopy for treating lumbar foraminal stenosis (LFS). However, no studies have assessed the mid-term clinical results of endoscopic techniques in spite of their relatively long history. In this study, we report 20 consecutive cases of LFS treated by our microendoscopic technique focusing on clinical results with a follow-up of at least two years.

Methods

Twenty consecutive cases of LFS treated with microendoscopic decompression were followed up at 1, 2, 6, and 12 months postoperatively and annually thereafter. The patients were 14 males and 6 females, and the mean age at the time of surgery was 64.7 years. The Japanese Orthopaedic Association (JOA) score was used as the clinical outcome index.

Results

Of the 20 patients, 16 were monitored successfully for more than 2 years. The follow-up rate was 80.0%, and the mean follow-up period was 66.3 months. The JOA score improved from 13.8 points before surgery to 24.6 points at final follow-up. Revision fusion surgeries were performed in two cases for LFS recurrence.

Conclusions

The microendoscopic technique effectively treats LFS.

Radiographic and clinical outcomes of huge lumbar disc herniations treated by transforaminal endoscopic discectomy

OBJECTIVES

Large Central disc herniations (occupying more than 50% of canal area) are notorious as they are generally associated with worse outcomes and are technically difficult to manage. Transforaminal endoscopy (TELD) has evolved to become an interesting alternative for lumbar disc herniations. The aim of the paper is to review our technique of transforaminal endoscopy in large central disc herniations and describe the clinical and radiographic results. We also describe an innovative technique of intraoperative epidurography to assess the adequacy of decompression in some cases with severe canal compromise.

PATIENTS AND METHODS

We performed a retrospective analysis of all the patients undergoing TELD from December 2012 to October 2018 for huge central lumbar disc herniations. The procedure was done under local anaesthesia and required a more horizontal approach angle, undercutting of superior articular process and posterior annular release to reach the herniated fragment in the epidural space. In severe cases, a radiopaque dye was introduced via trans-sacral catheter to check the adequacy of decompression. The disc height, lumbar lordosis, segmental lordotic angle on standing radiographs and Canal cross sectional area(CSA) on MRI were evaluated preoperatively and compared with postoperative images at the end of 1 year/final follow-up. The Visual analogue scale(VAS) for Back and Leg pain and Oswestry disability index (ODI), MacNab criteria, return to daily activities, return to work, patient satisfaction rate and recommendation to others were the clinical outcomes evaluated. The percentage of patients achieving the Minimal clinically important difference (MCID) of 3 points for VAS and 12 points for ODI was calculated.

RESULTS

A total of 18 patients, with an average age of 35.1years (range 20-61), were operated. The mean VAS back improved from 5.7(±1.77) to 1(±0.77) and VAS leg improved from 7.3(±1.37) to 1.1(±1.09). The ODI improved from 49.88(±11.42) to 13.88(±7.28) at final follow-up. According to MacNab criteria, 17 patients had excellent and 1 had good outcome at final follow-up. The patient satisfaction rate was 90.5%, with 94% patient recommendation rate. All the patients returned to daily activities and work/modified work within a median of 5 weeks. There was 1 patient who required conversion to open surgery due to incidental dural tear, 1 patient who had a remnant disc required a revision tubular discectomy and 1 patient who had recurrence at 6 weeks and again at 2 years which was treated by repeat TELD. Five patients had impending cauda equina. All the patients achieved the MCID for VAS and ODI within a median period of 6 weeks and 3 months, respectively. The recovery rate was 90.1%. Five patients had grade 4 weakness of great toe/ankle dorsiflexion, one also had ankle flexion weakness preoperatively which improved after surgery. The CSA improved from a preoperative mean of 62.26(±30.3)mm² to 122.16(±56.5)mm² postoperatively. The CSA improved to 141.05(±63.86)mm² at 1 year followup. The average disc height which was 9.71 mm(±2.4) was maintained at follow-up of one year which was 9.21 mm(±2.4). The lumbar lordosis and segmental lordotic angle changed from 27.08°(±15.9) and 2.82°(±5.7) to 35.8°(±8.56) and 4.85°(±4.39) respectively.

CONCLUSION

TELD may be considered as an alternative to microdiscectomy or fusion procedures for huge central disc herniations with favourable outcomes. However, sufficient expertise with the procedure is necessary. Intraoperative decompression may be confirmed with intraoperative epidurography. The patient acceptability of the procedure is good and causes minimal disruption of the normal anatomy.

Percutaneous Endoscopic Lumbar Foraminotomy for Foraminal Stenosis with Postlaminectomy Syndrome in Geriatric Patients

INTRODUCTION

Postlaminectomy syndrome (PLS) or failed back surgery syndrome is a condition characterized by persistent pain following a back surgery. Degenerative processes may result in foraminal stenosis development over time, even after a successful surgery. Percutaneous endoscopic lumbar foraminotomy (PELF) offers a minimally invasive means of treating foraminal stenosis after a back surgery. The objective of this study was to evaluate the outcomes of PELF for foraminal stenosis with PLS in geriatric patients.

METHODS

Two-year follow-up data were collected from 21 consecutive patients aged 65 years or older (mean age, 72.4 years) who underwent PELF for foraminal stenosis with PLS. Transforaminal endoscopic foraminal decompression was performed under local anesthesia. Outcomes were assessed using visual analog scale pain score, Oswestry Disability Index, and modified Macnab criteria.

RESULTS

Mean visual analog scale for leg pain improved from 8.48 at baseline to 3.33 at 6 weeks, 2.10 at 1 year, and 2.19 at 2 years after PELF (P < 0.01). Mean Oswestry Disability Index improved from 67.29 at baseline to 30.69 at 6 weeks, 22.50 at 1 year, and 20.81 at 2 years after PELF (P < 0.01). Based on the modified Macnab criteria, excellent or good results were obtained in 81.0% of patients and symptomatic improvements were obtained in 95.2% of patients.

CONCLUSIONS

The transforaminal endoscopic approach can provide a better access angle to achieve a sophisticated foraminal decompression with less facet and dural injury. Therefore, PELF under local anesthesia can be useful for PLS or postoperative foraminal stenosis in elderly patients.

Transforaminal full-endoscopic lumbar discectomy under local anesthesia in awake and aware conditions: the inside-out and outside-in techniques

PURPOSE OF THE REVIEW

Transforaminal full-endoscopic lumbar discectomy (TELD) under local anesthesia was first introduced in Japan in 2003. Initially referred to as percutaneous endoscopic discectomy, in 2018, a consensus was reached worldwide and the preferred term is now TELD. The procedure requires only an 8-mm skin incision and causes minimal damage to the paravertebral muscles. Thus, it is the least invasive disc surgery. In this review, we introduce two types of the TELD surgery.

RECENT FINDINGS

Initially, TELD was performed as the "inside-out" technique but was associated with reports of postoperative dysesthesia due to exiting nerve injury. Recently, the "outside-in" technique after foraminoplasty was proposed for safer insertion of the cannula into the disc. Foraminoplasty can widen the narrow foramen, thereby allowing the 8-mm cannula to pass through easily and safely, and thus injury to the exiting nerve root can be theoretically avoided. We described two types of the TELD in this review. Surgeons should be familiar with the inside-out and outside-in techniques for TELD; therefore, we can select appropriate technique for each case.

Anterior lumbar interbody fusion (ALIF): biometrical results and own experiences

Lumbar fusion is a mainstay in the treatment of low back pain resulting from degenerative disc disease. Anterior lumbar interbody fusion (ALIF) has become a reasonable treatment technique to achieve indirect foraminal decompression with high fusion rates. The aim of the study was to analyse the biometrical parameters of the lumbar spine and the clinical outcome. The medical records of 51 patients treated with ALIF between 2012 and 2016 were retrospectively reviewed. Anterior and posterior disc height (DH), lumbar lordosis (LL), local disc angle (LDA) and foraminal dimensions were obtained on pre- and postoperative plain radiographs and computed tomography scans using ImageJ and Surgimap software according to the pedicle–pedicle technique. To evaluate the interbody fusion status on the last follow-up CT scans, we used Bridwell criteria. Preoperative and 12 months postoperative Oswestry Disability Index (ODI) scores were determined for all patients. The average length of hospitalisation was 4 days. Most of the patients had degenerative disc disease with foraminal stenosis. Five patients had early complications like paresthesia of lower limbs, sympathetic dysfunction or wound infections, but there were no major complications. Statistically significant (P < .01) improvement was observed in foraminal dimensions (area = 49%, height = 33% and width = 19%), anterior DH (49%), posterior DH (69%), LDA (47%) and LL (17.5%). Posterior DH correlated significantly with foramen height improvement. Radiographic evidence of fusion according to the modified Bridwell criteria (grade I and grade II) was observed in 96% (49/51) of the patients in the last CT of the lumbar spine. We also observed significant improvement in functional recovery in 94% of patients. The mini-open ALIF approach is a reasonable alternative to the more extensive posterior approaches. ALIF significantly restores the height of the intervertebral disc, indirectly increases foraminal dimensions, increases lordosis angle with significant short and long-term pain relief and functional recovery.

Laser-assisted endoscopic lumbar foraminotomy for failed back surgery syndrome in elderly patients

Elderly patients with failed back surgery syndrome (FBSS) or post-laminectomy foraminal stenosis have a higher risk of perioperative morbidity with extensive revision surgery. Thus, there is a need for safer and less invasive surgical options, such as laser-assisted endoscopic lumbar foraminotomy (ELF). A pin-point laser beam can allow precise tissue ablation and dissection in fibrotic adhesion tissues while preventing normal tissue injury. The present study aimed to describe the surgical technique of laser-assisted ELF and to evaluate the clinical outcomes of elderly patients with FBSS. Two-year follow-up data were collected from 26 consecutive patients aged 65 years or older who were treated with laser-assisted ELF for FBSS. Full-endoscopic foraminal decompression was performed using a side-firing laser and mechanical instruments. The average age of the patients was 70.2 years (range, 65-83 years). The mean visual analog pain score for leg pain improved from 8.58 at baseline to 3.35 at 6 weeks, 2.19 at 1 year, and 2.35 at 2 years after ELF (P < 0.001). The mean Oswestry disability index improved from 65.93 at baseline to 31.41 at 6 weeks, 21.77 at 1 year, and 20.64 at 2 years after ELF (P < 0.001). Based on the modified Macnab criteria, excellent or good results were obtained in 84.6% patients and symptomatic improvements were obtained in 92.3%. Extensive revision surgery in elderly patients might cause significant surgical morbidities. Laser-assisted ELF under local anesthesia could be a safe and effective surgical alternative for such patients at risk.

Endoscopic transforaminal lumbar interbody fusion: a comprehensive review

INTRODUCTION

Endoscopic spine surgery has been developed as a minimally invasive technique for decompression in patients with lumbar disc herniation or lumbar stenosis. Recent reports have described the use of endoscopic technology in lumbar fusion surgeries, especially for transforaminal lumbar interbody fusion (TLIF). This review aimed to summarize the current techniques of endoscopic TLIF and to discuss the benefits, limitations, and future perspectives of endoscopic lumbar fusion surgery.

AREAS COVERED

This review covered the English-language medical literature published in Medline and focused specifically on endoscopic technologies incorporated into minimally invasive TLIF. The endoscopic TLIF techniques are categorized here according to the properties of the endoscope: percutaneous endoscopic TLIF, biportal endoscopic TLIF, and microendoscopic TLIF. Even though most authors have reported favorable clinical and radiological outcomes of endoscopic TLIF, such evidence originates mainly from case series.

EXPERT OPINION

Although the current level of evidence is low and the technical relevance of the technique is controversial, the key concept and early results of endoscopic TLIF are promising. Technical advancements to improve safety and reduce technical complexity, as well as comparative cohort studies and randomized clinical trials with long-term follow-up are required to promote the adoption of endoscopic TLIF in clinical practice.

Preoperative Design for the Posterolateral Approach in Full-Endoscopic Spine Surgery for the Treatment of L5/S1 Lumbar Disc Herniation

OBJECTIVE

Full-endoscopic spine surgery (FESS) is a relatively less invasive treatment for lumbar disc herniation (LDH). This study investigated the optimal operative route of the posterolateral approach (PLA) of FESS for the treatment of L5/S1 LDH.

METHODS

Between June 2016 and November 2018, a total of 21 patients with leg pain due to L5/S1 LDH underwent PLA of FESS. According to the partial removal of the superior articular process (SAP) of the L5/S1 facet joint (FJ), we categorized these patients into 2 groups. LDH type, anatomical configurations (FJ, sacral ala [SA], and iliac crest [IC]), the presence or absence of spondylolysis, operation time, and operative outcome were compared between these 2 groups.

RESULTS

Although the anatomical configuration of the FJ was the most important factor for the necessity of SAP removal, the configuration of the SA and IC did not restrict endoscope insertion and subsequent LDH removal. Even in intracanal LDH, the removal of SAP was not absolutely required depending on the FJ configuration. Furthermore, the presence of spondylolysis was a factor associated with the unnecessity of SAP removal.

CONCLUSION

Detailed radiological examination of the FJ configuration is an important preoperative investigation to determine the optimal operative route for PLA of FESS.

Clinical outcome of percutaneous lumbar foraminoplasty using a safety-improved device in patients with lumbar foraminal spinal stenosis

Lumbar foraminal spinal stenosis (LFSS) is defined as the narrowing of the nerve root exit associated with a herniated intervertebral disc, osteoarthritic changes in the facet joints, or a hypertrophied ligamentum flavum, which can provoke neurogenic claudication. To achieve effective and safe decompression of the lumbar spinal foramen, a specially designed instrument (Claudicare, SEAWON Meditech, Bucheon-si, Gyeonggi-do, Republic of Korea) for percutaneous lumbar foraminoplasty (PLF) was invented. The purpose of this study was to evaluate the clinical efficacy and safety of the newly devised instrument in patients with LFSS.PLF was performed for LFSS by a single pain physician. For each patient, an 11-point numerical rating scale (NRS) pain score-the Oswestry Disability Index (ODI)-and the duration of walking without radicular pain were evaluated at the 3-month follow-up. The successful responder percentage was defined as ≥50% reduction from the baseline NRS score with improvement in ODI and duration of walking.Among 24 patients who underwent PLF, 15 patients showed successful responses. The NRS pain score and duration of walking without radicular pain were improved significantly from baseline at the 3-month follow-up (P < .01). The ODI was also decreased, but the difference was not statistically significant (P = .09). The NRS pain score and walking duration without pain at 3 months were statistically significantly different between the groups (P < .001 and P = .01, respectively), whereas there was no statistically significant difference in improvement in ODI between the groups (P = .23). No serious adverse events occurred in the study.In conclusion, PLF using the Claudicare device may be an optimal and safe option for managing intractable LFSS on an outpatient basis.

Endoscopic Lumbar Surgery: The State of the Art in 2019

This study was aimed to provide a brief historical perspective to facilitate appreciation of current techniques, describe outcomes of endoscopic lumbar surgery relative to those of existing techniques, and identify topics in need of study and future directions for the field of endoscopic lumbar surgery. Using the PubMed database, a comprehensive search was conducted to identify peer-reviewed English language articles pertaining to endoscopic lumbar surgery. Lack of focus on pertinent techniques or lack of outcome measures constituted exclusion criteria. A majority of included articles were published from 2015–2019. A context with which to appreciate the application of endoscopic lumbar techniques is established. An abundance of case series and several recent comparison studies have documented the benefits and potential pitfalls of these methods in the past two decades. The advantages of endoscopic lumbar spine surgery are widely touted to include reduced perioperative morbidity, including blood loss, operative time and immediate postoperative recovery, minimal structural trauma resulting from surgery, generally positive patient report outcome scores and the potential to contain costs. Additional high-quality research assessing outcomes of endoscopic lumbar surgery are certainly needed and currently expected given the rapid expansion of the field in recent years.

Percutaneous Stenoscopic Lumbar Decompression with Paramedian Approach for Foraminal/Extraforaminal Lesions

The lumbar foramen is affected by different degenerative diseases, including extraforaminal disc herniation, foraminal stenosis (FS), and degenerative or spondylolytic spondylolisthesis. The purpose of this study was to describe percutaneous stenoscopic lumbar decompression with a paramedian approach (para-PSLD) for foraminal/extraforaminal lesions. All operative procedures were performed using a complete uniportal endoscopic instrument system. The para-PSLD can be easily applied to patients with FS and narrow disc space or facet joint hypertrophy. The anatomical view of a para-PSLD is similar to that of a conventional open surgery and allows for good visualization of the foraminal/extraforaminal areas. We suggest that para-PSLD is an alternative and minimally invasive procedure to treat degenerative lumbar foraminal/extraforaminal stenoses.

Predictors of Clinical Outcome After Endoscopic Partial Facetectomy for Degenerative Lumbar Foraminal Stenosis

OBJECTIVE

Endoscopic partial facetectomy (EPF) is an effective option for decompressing the lumbar exiting root without causing spinal instabilities in the treatment of patients with degenerative lumbar foraminal stenosis. The aim of the present study was to identify the preoperative risk factors of poor clinical outcomes after EPF in patients with degenerative lumbar foraminal stenosis.

METHODS

A total of 51 consecutive patients who had undergone EPF from 2012 to 2015 were included in the present study. The clinical outcomes were evaluated using the visual analog scale (VAS), Oswestry disability index (ODI), and Short-Form 36-item (SF-36) outcome questionnaires. The preoperative radiological risk factors were measured using the lumbar Cobb's angle, disc wedging angle, lumbar lordosis (LL), segmental lordosis, disc height index, presence of spondylolisthesis, and morphological changes (no change, horizontal collapse, vertical collapse) of the exiting root within the most stenotic level on preoperative magnetic resonance imaging.

RESULTS

The VAS, ODI, and SF-36 scores had significantly improved at the 1-month follow-up visit compared with the baseline mean values and were maintained within the 2-year follow-up period. A correlation analysis revealed significant relationships between various preoperative factors and clinical outcomes. On multiple regression analysis, the morphological change of vertical collapse significantly predicted the VAS, ODI, and SF-36 scores, and LL significantly predicted the ODI and SF-36 scores.

CONCLUSIONS

A morphological change in vertical collapse found on preoperative magnetic resonance imaging and decreased LL were significant predictors of poor clinical outcomes after EPF in the treatment of lumbar foraminal stenosis.

Comparative Analysis between Three Different Lumbar Decompression Techniques (Microscopic, Tubular, and Endoscopic) in Lumbar Canal and Lateral Recess Stenosis: Preliminary Report

PURPOSE

The purpose of our study is to compare the results of spinal decompression using the full-endoscopic interlaminar technique, tubular retractor, and a conventional microsurgical laminotomy technique and evaluate the advantages and clinical feasibility of minimally invasive spinal (MIS) lumbar decompression technique in the lumbar canal and lateral recess stenosis.

METHODS

The authors retrospectively reviewed clinical and radiological data from 270 patients who received microsurgical (group E: 72 patients), tubular (group T: 34 patients), or full-endoscopic decompression surgery (group E: 164 patients) for their lumbar canal and lateral recess stenosis from June 2016 to August 2017. Clinical (VAS, ODI, and Mcnab criteria), radiologic (spinal canal diameter, segmental dynamic angle, and disc height), and surgical outcome parameters (CPK level, Operative time, blood loss, and hospital stay) were evaluated pre- and postoperatively and compared among the three groups by means of statistical analysis. Failed cases and complications were reviewed in all groups.

RESULTS

The mean follow-up period was 6.38 months. The Overall clinical success rate was 89.4%. All groups showed favorable clinical outcome. The clinical and radiologic results were similar in all groups. Regarding surgical outcome, group E showed longer operation time than group M and T (group E: 84.17 minutes/level, group M: 52.22 minutes/level, and group T: 66.12 minutes/level) (p<0.05). However, groups E and T showed minimal surgical invasiveness compared with group M. Groups E and T showed less immediate postoperative back pain (VAS) (group E: 3.13, group M: 4.28, group T: 3.54) (p<0.05), less increase of serum CPK enzyme (group E: 66.38 IU/L, group M: 120 IU/L, and group T: 137.5 IU/L) (p<0.05), and shorter hospital stay (group E: 2.12 days, group M: 4.85 days, and group T: 2.83 days) (p<0.05). The rates of complications and revisions were not significantly different among the three groups.

CONCLUSIONS

MIS decompression technique is clinically feasible and safe to treat the lumbar canal and lateral recess stenosis, and it has many surgical advantages such as less muscle trauma, minimal postoperative back pain, and fast recovery of the patient compared to traditional open microscopic technique.

Biportal Endoscopic Spinal Surgery for Bilateral Lumbar Foraminal Decompression by Switching Surgeon's Position and Primary 2 Portals: A Report of 2 Cases With Technical Note

Total facetectomy with/without fusion and facet-preserving microforaminotomy have been performed as conventional surgical treatments for lumbar foraminal stenosis (LFS). Recently, endoscopic spinal surgery has been introduced as a minimally invasive therapeutic modality of LFS by several authors. We report two cases of bilateral LFS at lumbosacral junction level successfully treated with a novel biportal endoscopic spine surgery (BES) technique using primary 2 portals. Two patients presented with chronic onset of back pain and neurogenic claudication symptom. They were diagnosed with bilateral LFS at L5-S1 level from magnetic resonance imaging and computed tomography preoperatively. BES for bilateral foraminal decompression was performed via contralateral approach bilaterally without additional skin incision or surgical trajectory by switching surgeon's position and primary 2 portals. After the surgery, preoperative patients' back and leg pain resolved and unilateral leg weakness of the 2 patients gradually improved in a few months. Postoperative radiologic images revealed significantly enlarged bilateral foramens at L5-S1 level.

The Usefulness of Percutaneous Endoscopic Technique in Multifocal Lumbar Pathology

Introduction. The multifocal lumbar pathology including disc herniation and stenosis in the spinal canal or foramen has been considered the most difficult to approach surgically. It often requires mandatory dual approaches and/or fusion techniques. Traditional percutaneous endoscopic lumbar transforaminal and interlaminar approach has been focused on unifocal disc herniation. However, the development of endoscopic spinal instruments and surgical technique has broadened surgical indication and therapeutic boundary in endoscopic spine surgery. Cases Presentation. The authors present outcomes of four patients with multilumbar pathology including highly inferior migrated disc combined with lateral recess stenosis, multifocal disc herniation, bilateral disc herniations in spinal canal and foraminal disc herniation combined with central canal stenosis. They were successfully treated by percutaneous uniportal full endoscopic approach with single incision. Conclusion. Percutaneous endoscopic spine surgery is a safe and effective tool to figure out multilumbar pathology in a minimal invasive way.

Comparison of Transforaminal Percutaneous Endoscopic Lumbar Discectomy with and without Foraminoplasty for Lumbar Disc Herniation: A 2-Year Follow-Up

BACKGROUND

Both transforaminal percutaneous endoscopic lumbar discectomy with foraminoplasty (TF PELF) and transforaminal percutaneous endoscopic lumbar discectomy without foraminoplasty (TF PELD) were developed for lumbar disc herniation (LDH) patients. However, the safety and effectiveness between the TF PELF and TF PELD have not been investigated.

METHODS

Of the included 140 LDH patients, 62 patients received TF PELF (PELF group) and 78 patients received TF PELD (PELD group). The operation time, the duration of staying at the hospital, and complication incidences were recorded. All patients were followed up for 2 years, where low back and leg visual analogue scale (VAS) pain ratings and Oswestry Disability Index (ODI) were compared between the 2 groups before and after surgery. Modified Macnab criterion was estimated for all patients at postoperative 2 years.

RESULTS

There were no significant difference of the operation time, number of days staying at the hospital, and the incidence of complications between the 2 groups (P > 0.05). Two cases in the PELF group and 1 case in the PELD group received a second surgery due to unrelieved symptoms postoperatively. Low back and leg VAS and ODI scores decreased in both groups after operation (P < 0.01), respectively, but were not significant between the 2 groups over time (P > 0.05). Six patients in the PELF group and 3 patients in the PELD group did not continue the follow-up; thus, only 131 patients completed Macnab evaluation. The satisfactory rate was reported as 80.4% in the PELF group and 90.7% in the PELD group (P > 0.05).

CONCLUSIONS

This study suggested that the safety and effectiveness of TF PELF are comparable to TF PELD for LDH patients.

Working Cannula-Based Endoscopic Foraminoplasty: A Technical Note

Purpose

Percutaneous endoscopic lumbar discectomy (PELD) is a minimally invasive disc surgery that can be performed under local anesthesia and requires only an eight-mm skin incision. For the patients with lumbar foraminal stenosis, the migrated disc is difficult to remove with a simple transforaminal approach. In such cases, the foraminoplasty techniques can be used. However, obtaining efficient foramen enlargement while minimizing radiation exposure and protecting the nerves can be challenging.

Methods

In this study, we propose a new technique called the Kiss-Hug maneuver. Under endoscopic viewing, we used the bevel tip of a working cannula as a bone reamer to enlarge the foramen. This allowed us to efficiently enlarge the lumbar foramen endoscopically without the redundancy and complications associated with reamers or trephines.

Results

Details of the four steps of the Kiss-Hug maneuver are reported along with adverse events. The advantages of this new technique include minimizing radiation exposure to both the surgeon and the patient and decreasing the overall operation time.

Conclusion

The endoscopic Kiss-Hug maneuver is a useful and reliable foraminoplasty technique that can enhance the efficiency of foraminoplasty while ensuring patient safety and reducing radiation exposure.

Foraminoplasty at the Tip or Base of the Superior Articular Process for Lateral Recess Stenosis in Percutaneous Endoscopic Lumbar Discectomy: A Multicenter, Retrospective, Controlled Study with 2-Year Follow-Up

Objective

To compare the clinical efficacy and complications which obtained foraminoplasty at the tip or base of the superior articular process (SAP) for the patients with lateral recess stenosis treated by percutaneous endoscopic lumbar discectomy (PELD).

Methods

Between January 2015 and January 2016, 156 patients of lumbar disc herniation accompanying with lateral recess stenosis were treated with PELD in five tertiary hospitals and fulfilled the 2-year follow-up. Among them, 78 patients obtained a foraminoplasty at the tip of SAP (group A), and foraminoplasty at the base of SAP was performed in the other 78 cases (group B). Clinical efficacy was evaluated using the visual analog scale (VAS) score for back and leg pain, Oswestry Disability Index (ODI), and 36-item Short-Form Health Survey (SF-36) score. The intervals of follow-up were scheduled at 1 month, 3 months, 6 months, 1 year, and 2 years after surgery.

Results

Mean operative duration is shorter in group B (55 versus 61 min, P = 0.047). Only one case belonged to group A could not tolerate the neural irritation and required conversion to an open procedure. During the surgery, no dura tears, cauda equina syndrome, or infections were observed. 5 patients experienced transient dysesthesia located at the exiting nerve in group A, while no cases complained dysesthesia in group B. 2 cases who suffered temporary motor weakness all belonged to group A. A total of 5 cases obtained a revision surgery after recurrence in the follow-up, in which 3 patients belonged to group A. Compared to the preoperative data, significant improvements in VAS scores of low back pain and sciatica, ODI, and SF-36 PCS and MC were observed in the follow-up, respectively (P < 0.05, respectively). However, no statistical difference was observed at all time-points after surgery between these two groups (P > 0.05, respectively).

Conclusions

For the patients of LDH accompanying with lateral recess stenosis, compared with the routine foraminoplasty at the tip of SAP, our modified foraminoplastic technique does not only change place of foraminoplasty to the base of SAP but also simplified puncture process in transforaminal PELD. Although there was no significant difference in symptom relief, the modified foraminoplasty showed the advantages in decreasing the incidence of postoperative neural dysfunction and reducing operation time.

A less invasive surgery using a full-endoscopic system for L5 nerve root compression caused by lumbar foraminal stenosis

Background

Percutaneous endoscopic lumbar discectomy (PELD) is a relatively less invasive treatment for lumbar disc herniation (LDH). This study investigated the usefulness of a full-endoscopic system for PELD to treat L5 nerve root compression caused by lumbar foraminal stenosis (L5-LFS).

Methods

Between November 2016 and December 2017, a total of 10 patients with unilateral leg pain due to L5-LFS underwent surgery using a full-endoscopic system for PELD. Patients with bilateral L5-LFS or L5-LFS with coexisting LDH and/or spondylolysis were excluded from this study. A percutaneous endoscopic translaminar approach (PETA) was performed via the ipsilateral vertebral isthmus using a 3.5-mm diameter high-speed drill. Preoperative and postoperative statuses were evaluated using the modified Japanese Orthopedic Association (mJOA) and Numerical Rating Scale (NRS) scores.

Results

The patients' mean age was 62.2 years; there were 7 male and 3 female patients. The mean recovery rate was 58.2% with the mJOA score; mean pre- and postoperative NRS scores were 7.4 and 2.3, respectively. The mean operative time was 77.6 min. Although there were no major complications, pain did not improve in an 80-year-old woman with coexisting spondylolisthesis (Meyerding grade 2).

Conclusions

PETA using a full-endoscopic system is a safe and effective minimally invasive treatment for L5-LFS, with potential to be an alternative surgical strategy for L5-S1 interbody fusion.

Transforaminal Percutaneous Endoscopic Lumbar Decompression by Using Rigid Bendable Burr for Lumbar Lateral Recess Stenosis: Technique and Clinical Outcome

Background

Open laminectomy has been regarded as the standard surgical procedure for lumbar lateral recess stenosis during the last decades. Although percutaneous endoscopic lumbar decompression has led to successful results comparable with open decompression, its application in LSS with is still challenging and technically demanding. Here, we report the surgical procedure and preliminary clinical outcomes of transforaminal percutaneous endoscopic lumbar decompression (PELD) by using flexible burr for lumbar lateral recess stenosis.

Method

A retrospective study was performed for the patients with lumbar lateral recess stenosis receiving PELD by using flexible burr. The indications of surgery were moderate to severe stenosis, persistent neurological symptoms, and failure of conservative treatment. The patients with mechanical back pain, more than grade I spondylolisthesis, or radiographic signs of instability were not included. Before the operation, the transforaminal epidural lidocaine injections were carried out to make the diagnosis more precise and accurate. Radiologic findings were investigated, and visual analog scale (VAS) for back and leg pain, Oswestry Disability Index, and modified Macnab criteria were analyzed at the different time of preoperation, postoperation, 3 months, 6 months, and 12 months.

Results

The follow-up period was 12 months. The mean VAS scores for back and leg pain immediately improved from 7.9 ± 1.2 to 2.8± 1.3, 2.4 ± 1.0, and 2.3 ± 1.0, respectively. The mean visual analog scale scores (VAS) for back pain and leg pain were significantly improved after PELD. The preoperative ODI dropped from 69.1 ± 7.3 to 25.9 ± 8.7, 25.0± 6.9, and 24.7 ± 6.4, respectively. The final outcome was excellent in 39.6%, good in 47.9%, fair in 8.3%, and poor in 4.17%. 87.5% of excellent-to-good ratio was achieved on the basis of Macnab criteria at postoperative 12 months. The complications were limited to transient postoperative dysesthesia (one case), temporary pain aggravation (six cases), and neck pain during the operation (one case).

Conclusion

This observation suggests that the clinical outcomes of PELD for lateral recess stenosis were excellent or showed good results. This minimally invasive technique would be helpful in choosing a surgical method for lateral recess stenosis.

Unilateral Biportal Endoscopic Spinal Surgery Using a 30° Arthroscope for L5-S1 Foraminal Decompression

Foraminal decompression using a minimally invasive technique to preserve facet joint stability and function without fusion reportedly improves the radicular symptoms in approximately 80% of patients and is considered one of the good surgical treatment choices for lumbar foraminal or extraforaminal stenosis. However, proper decompression was not possible because of the inability to access the foramen at the L5–S1 level due to prominence of the iliac crest. To overcome this challenge, endoscopy-based minimally invasive spine surgery has recently gained attention. Here, we report the technical skills required in unilateral extraforaminal biportal endoscopic spinal surgery using a 30° arthroscope to enable foraminal decompression at the L5–S1 level. Two 0.8-cm portals were created 2 cm lateral from the lateral border of the pedicles at the L5–S1 level. After sufficient working space was made, half of the superior articular process (SAP) in the hypertrophied facet joint was removed using a high-speed burr and a 5-mm wide osteotome, whereas the remaining inside part of the SAP was removed using a Kerrison punch and pituitary punch. The foraminal ligamentum flavum should be removed to inspect the conditions of the L5 exiting root and disc. Removing of the extruded disc could decompress the L5 root. The extraforaminal approach using a 30° arthroscope is considered a minimally invasive alternative technique for decompressing foraminal stenosis at the L5–S1 level that preserves facet stability and provides symptomatic relief.

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.

Outcomes of percutaneous endoscopic trans-articular discectomy for huge central or paracentral lumbar disc herniation

PURPOSE

This study reports a new technique known as percutaneous endoscopic trans-articular discectomy (PETAD) for huge central/paracentral lumbar disc herniation (LDH).

METHODS

Sixteen patients with huge central/paracentral LDH who underwent PETAD in our department from July 2015 to July 2016 were retrospectively analyzed. Clinical outcomes were evaluated according to pre-operative and post-operative visual analog scale (VAS) and Oswestry disability index (ODI) scores and the MacNab criteria. Immediate post-operative MRI and CT were conducted to confirm complete removal of LDH along with follow-up flexion-extension X-ray to observe lumbar stability.

RESULTS

The huge central/paracentral LDH was completely removed by PETAD in 16 patients, as confirmed by post-operative MRI and CT. Leg pain was eased after removal of the disc herniations. The satisfactory (excellent/good) results were 93.7%. The mean follow-up duration was 15.6 (range, 3-24) months. The mean pre-operative VAS and ODI scores were 5.72 ± 1.18 (range, 4-9) and 60.1 (range, 51-87), respectively, which decreased to 1.26 ± 0.81 (range, 0-3) and 18.1 (range, 10-31), respectively at the third month post-operatively and to 0.78 ± 0.62 (range, 0-1) and 7.2 (range, 0-15), respectively by the last follow-up visit. No recurrence and segmental instability was observed in any of the 16 patients during the follow-up period.

CONCLUSION

PETAD could be a good alternative for treatment of huge central/paracentral LDH.