Posterolateral percutaneous endoscopic lumbar foraminotomy for L5-S1 foraminal or lateral exit zone stenosis. Technical note

Transforaminal endoscopic lumbar foraminotomy for octogenarian patients

Background

Radiculopathy caused by lumbar foraminal stenosis in older people has become more common in the aging general population. However, patients aged ≥80 years rarely undergo conventional open surgery under general anesthesia because of the high risk of peri-operative morbidity and adverse events. Therefore, less invasive surgical alternatives are needed for older or medically handicapped patients. Transforaminal endoscopic lumbar foraminotomy (TELF) under local anesthesia may be helpful in at-risk patients, although only limited information is available regarding the clinical outcomes of this procedure in octogenarians. Therefore, this study aimed to investigate the safety and efficacy of TELF for treating radiculopathy induced by foraminal stenosis in octogenarian patients.

Methods

Overall, 32 consecutive octogenarian patients with lumbar foraminal stenosis underwent TELF between January 2019 and January 2021. The inclusion criterion was unilateral radiculopathy secondary to lumbar foraminal stenosis. The pain focus was confirmed using imaging studies and selective nerve blocks. Full-scale foraminal decompression was performed using a percutaneous transforaminal endoscopic approach under local anesthesia. Surgical outcomes were assessed using the visual analog pain score, Oswestry Disability Index, and modified MacNab criteria.

Results

The pain scores and functional outcomes improved significantly during the 24-month follow-up period, and the rate of clinical improvement was 93.75% in 30 of the 32 patients. None of the patients experienced systemic complications.

Conclusion

TELF under local anesthesia is an effective and safe treatment for foraminal stenosis in octogenarian or medically compromised patients. The mid-term follow-up did not reveal any significant progression in spinal stability. Therefore, this endoscopic procedure can be an effective alternative to aggressive surgery for managing lumbar foraminal stenosis in octogenarian patients with intractable radiculopathy.

Reoperations After Percutaneous Endoscopic Transforaminal Decompression for Treating Lumbar Spinal Stenosis: Incidence and Predictors

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

The main purpose of the present study was to report the incidence and identify predictors of reoperation in patients with lumbar spinal stenosis (LSS) treated with percutaneous endoscopic transforaminal decompression (PETD).

METHODS

This study retrospectively reviewed consecutive patients with LSS who underwent PETD at our center between January 2016 and July 2020. The incidence of reoperations was calculated. We then designed a surgical period-matched case-control study to identify predictors among demographic data, clinical baseline data, and imaging parameters.

RESULTS

This study identified 496 eligible patients. 33 (6.7%) patients underwent reoperation with a mean follow-up of 3 years, consisting 22 (4.4%) at the index level and 11 (2.2%) at the adjacent levels. There were significant differences in age and age-adjusted Charlson comorbidity index (AACCI) between the two groups, with younger age (P = .004) and lower AACCI (P = .019) in reoperation group. Age was identified as the sole independent predictor (P = .006). The duration of symptoms ≥12 months (P = .034) and the presence of heart problems (P = .012) were recognized as specific predictors among patients younger than 65 years.

CONCLUSIONS

In a mean follow-up of 3 years, the incidence of reoperation in LSS treated with PETD was 6.7%. A younger age was the independent predictor for reoperation. Younger patients with the duration of symptoms ≥12 months or without heart problems were more likely to undergo a second operation. Prospective randomized controlled trials are required to confirm these findings.

Comparison of full-endoscopic and tubular-based microscopic decompression in patients with lumbar spinal stenosis: a randomized controlled trial

PURPOSE

We aimed to demonstrate non-inferiority in terms of functional outcomes in patients with lumbar spinal stenosis who underwent full-endoscopic decompression compared with tubular-based microscopic decompression.

METHODS

This prospective, randomized controlled, non-inferiority trial included 60 patients with single-level lumbar spinal stenosis who required decompression surgery. The patients were randomly assigned in a 1:1 ratio to the full-endoscopic group (FE group) or the tubular-based microscopic group (TM group). Based on intention-to-treat analysis, the primary outcome was the Oswestry Disability Index score at 24 months postoperative. The secondary outcomes included the visual analog scale (VAS) score for back and leg pain, European Quality of Life-5 Dimensions (EQ-5D) score, walking time, and patient satisfaction rate according to the modified MacNab criteria. Surgery-related outcomes were also analyzed.

RESULTS

Of the total patients, 92% (n = 55) completed a 24-month follow-up. The primary outcomes were comparable between the two groups (p = 0.748). However, the FE group showed a statistically significant improvement in the mean VAS score for back pain at day 1 and at 6, 12, and 24 months after surgery (p < 0.05). No significant difference was observed in the VAS score for leg pain, EQ-5D score, or walking time (p > 0.05). Regarding the modified MacNab criteria, 86.7% of patients in the FE group and 83.3% in the TM group had excellent or good results at 24 months after surgery (p = 0.261). Despite the similar results in surgery-related outcomes, including operative time, radiation exposure, revision rate, and complication rate, between the two groups (p > 0.05), less blood loss and shorter length of hospital stay were observed in the FE group (p ≤ 0.001 and 0.011, respectively).

CONCLUSION

This study suggests that full-endoscopic decompression is an alternative treatment for patients with lumbar spinal stenosis because it provides non-inferior clinical efficacy and safety compared with tubular-based microscopic surgery. In addition, it offers advantages in terms of less invasive surgery. Trial registration number (TRN): TCTR20191217001.

Biomechanical limitations of partial pediculectomy in endoscopic spine surgery

BACKGROUND CONTEXT

Transforaminal endoscopic decompression is an emerging minimally invasive surgical technique in spine surgery. The biomechanical effects and limitations of resections associated with this technique are scarce.

PURPOSE

The objective of this study was to analyze the effects of three different extents of reduction at the craniomedial pedicle (10%, 25%, and 50%) and to compare them with the intact native side. In addition, the influence of bone quality on the resistance of the pedicle after reduction was investigated.

STUDY DESIGN

Biomechanical cadaveric study.

METHODS

Thirty lumbar vertebrae originating from six fresh frozen cadavers were tested under uniaxial compression load in a ramp-to-failure test: (1) the reduced pedicle on one side, and (2) the native pedicle on the other side. Of the 30 lumbar vertebrae, ten were assigned to each reduction group (10%, 25%, and 50%).

RESULTS

On the intact side, the median axial compression force to failure was 593 N (442.4-785.8). A reduction of the pedicle by 10% of the cross-sectional area resulted in a decrease of the axial load resistance by 4% to 66% compared to the intact opposite side (p=.046). The median compression force to failure was 381.89 N (range: 336-662.1). A reduction by 25% resulted in a decrease of 7% to 71% (p=.001). The median compression force to failure was 333 N (265.1-397.3). A reduction by 50% resulted in a decrease of 39% to 90% (p<.001). The median compression force to failure was 200.9 N (192.3-283.9). At 10% pedicle reduction, the Hounsfield units (HU) value and the absolute force required to generate a pedicle fracture showed significant correlations (ρ=.872; p=.001). At 25%, a positive correlation between the two variables could still be identified (ρ=.603; p=.065). At 50%, no correlation was found (ρ=-.122; p=.738).

CONCLUSION

Resection of the inner, upper part of the pedicle significantly reduces the axial resistance force of the pedicle until a fracture occurs.

CLINICAL SIGNIFICANCE

The extent of pedicle reduction itself plays only a limited role: once the cortical bone in the pedicle region is compromised, significant loss of resistance to loading must be anticipated.

Pain improvement and reoperation rate after full-endoscopic decompression for lateral recess stenosis: a 10-year follow-up

PURPOSE

To share long-term clinical outcomes and our experience with full-endoscopic interlaminar decompression (FEI) for lateral recess stenosis (LRS).

METHODS

We included all patients who underwent FEI for LRS from 2009 to 2013. VAS for leg pain, ODI, neurological findings, radiographic findings, and complications were analyzed at one week, one month, three months, and one year postoperation. The telephone interview for local patients with simple questions was done approximately ten years after the operation. International patients receive an email with the same questionnaire as local patients during the same follow-up period.

RESULTS

One hundred and twenty-nine patients underwent FEI for LRS with complete data during 2009-2013. Most of the patients (70.54%) had LRS radiculopathy for less than one year, mainly L4-5 (89.92%), followed by L5-S1 (17.83%). Early outcomes three months after surgery showed that most patients (93.02%) reported significant pain relief, and 70.54% reported no pain at their ODI scores were significantly reduced from 34.35 to 20.32% (p = 0.0052). In contrast, the mean VAS for leg pain decreased substantially by 3.77 points (p < 0.0001). There were no severe complications. At ten years of follow-up, 62 patients responded to the phone call or email. 69.35% of the patients reported having little or no back or leg pain, did not receive any further lumbar surgery, and were still satisfied with the result of the surgery. There were six patients (8.06%) who underwent reoperation.

CONCLUSION

FEI for LRS was satisfactory at 93.02%, with a low complication rate during the early follow-up period. Its effect seems to decline slightly in the long term at a 10-year follow-up. 8.06% of the patients subsequently underwent reoperation.

Morphometric change in intervertebral foramen after percutaneous endoscopic lumbar foraminotomy: an in vivo radiographic study based on three-dimensional foramen reconstruction

PURPOSE

This study aimed to perform in vivo three-dimensional (3D) quantitative measurements of morphometric changes in the foramen in patients with lumbar foraminal stenosis (LFS) undergoing percutaneous endoscopic lumbar foraminotomy (PELF) and investigate the relationship between anatomical changes in the foramen and clinical outcomes.

METHODS

We retrospectively reviewed consecutive patients with LFS treated with PELF between January 2016 and September 2020 at our centre. Clinical outcomes were evaluated. Foraminal volume (FV) and foraminal minimal area (FMA) were calculated using a novel vertebral and foramen segmentation method. A comparison of the anatomical parameters of the foramen were conducted between the satisfied and unsatisfied groups divided based on the modified MacNab criteria.

RESULTS

A total of 26 eligible patients with a mean follow-up of 3.6 years were enrolled. A significant increase was found in overall FV (71.5%) from 1.436 ± 0.396 to 2.464 ± 0.719 cm3 (P < 0.001) and FMA (109.5%) from 0.849 ± 0.207 to 1.780 ± 0.524 cm2. All clinical outcomes were significantly improved (P < 0.001) after PELF. No significant difference was found in changes in neither FV nor FMA between the two groups.

CONCLUSION

Clinical results and foraminal dimensions improved significantly after PELF, indicating that PELF was a prominent technique suitable for LFS because of the direct decompression at impingement structures. No relationship was found between morphometric changes and clinical outcomes, revealing that full-scale endoscopic decompression is necessary and adequate for LFS, and unsatisfactory outcomes are less likely to result from decompression procedure.

Correlation Between Postoperative Imaging Parameters and Clinical Outcomes of Percutaneous Endoscopic Transforaminal Decompression for Lumbar Spinal Foraminal and Lateral Recess Stenosis

Objective

To investigate the correlation between postoperative imaging parameters and clinical outcomes in patients with foraminal stenosis (FS) and lateral recess stenosis (LRS) who underwent percutaneous endoscopic transforaminal decompression (PETD).

Methods

The study included 104 eligible patients who underwent PETD, and the mean follow-up time was 2.4 years (range 2.2-3.6 years). Visual Analog Scale (VAS) scores, Oswestry Disability Index (ODI) scores, and the modified MacNab criteria were used to evaluate the clinical outcomes. The related parameters of the FS and LRS based on computed tomography and magnetic resonance imaging were measured before and after surgery. Correlations between the imaging parameters and clinical outcomes were investigated.

Results

The proportion of excellent and good results following MacNab evaluation was 82.6%. In the treatment of LRS, VAS-back, VAS-leg, and ODI at the 2-year follow-up were negatively correlated with postoperative facet joint length based on computed tomography. In the treatment of FS, the above clinical results were positively correlated with the variation of foraminal width and nerve root-facet distance before and after surgery based on magnetic resonance imaging.

Conclusion

PETD can achieve good clinical outcomes in the treatment of patients with LRS or FS. Postoperative facet joint length was negatively correlated with clinical outcomes of LRS patients. In FS patients, the variation in foraminal width and nerve root-facet distance before and after surgery were positively correlated with their clinical outcomes. These findings may help surgeons optimize treatment strategies and selection of surgical candidates.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Transforaminal Endoscopic Decompression for Foraminal Stenosis: Single-Arm Meta-Analysis and Systematic Review

OBJECTIVE

The objective of the study was to conduct a single-arm meta-analysis and comprehensive systematic review to identify the efficacy and safety of transforaminal endoscopic surgery for the treatment of lumbar foraminal stenosis (LFS).

METHODS

The meta-analysis was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement. The PubMed, Web of Science, and Embase databases were searched from inception to February 20, 2022. Primary research results were visual analog scale scores, Oswestry Disability Index scores, MacNab criterion scores, and reported adverse events. Subgroup analyses were performed on the primary outcome to evaluate the potential effects of several clinical factors that affected the results.

RESULTS

Of the 2020 studies identified, 9 met the inclusion criteria, and 316 participants were eligible for meta-analysis. The meta-analysis results found that transforaminal endoscopic surgery for the treatment of LFS was associated with a significant improvement in postoperative 12-month clinical indicators: 8 studies reported improvements in visual analog scale scores: -5.38, Oswestry Disability Index scores: -40.44, and MacNab criterion scores: odds ratio = 0.86; 8 studies reported 11.53% adverse events occurred in a total of 295 patients, and the most commonly reported event was transient postoperative dysesthesia, which occurred in 26 patients in a total of 6 studies with 240 patients (10.83%).

CONCLUSIONS

Transforaminal endoscopic surgery positively affects postoperative LFS patients' clinical indicators; however, high-level literature with randomized controlled trials is needed to confirm this technique's applicability in LFS.

Endoscopic lumbar foraminotomy for foraminal stenosis in stable spondylolisthesis

BACKGROUND

Open decompression with fusion is the gold-standard surgical technique for spondylolisthesis. However, it may be too extensive for patients with foraminal stenosis with stable spondylolisthesis. The endoscopic lumbar foraminotomy (ELF) technique was developed as a minimally invasive surgical option for foraminal stenosis. Some authors have reported the outcomes of ELF for various spondylolistheses. However, few studies have demonstrated foraminal stenosis in advanced stable spondylolisthesis. This study aimed to describe the surgical technique and results of ELF for radiculopathy due to foraminal stenosis in patients with stable spondylolisthesis.

METHODS

Consecutive 22 patients who suffered from radiculopathy with spondylolisthesis underwent ELF. The inclusion criterion was unilateral radicular leg pain due to foraminal stenosis in stable spondylolisthesis. After the percutaneous transforaminal approach, foraminal decompression was performed using various surgical devices under endoscopic visualization. Surgical outcomes were measured using the visual analog pain score, Oswestry disability index, and modified MacNab criteria.

RESULTS

Pain scores and functional outcomes improved significantly during the 12-month follow-up periods. The rate of clinical improvement was 95.5% (21 of 22 patients). One patient experienced a dural tear and subsequent open surgery.

CONCLUSION

ELF can be effective in foraminal stenosis in stable spondylolisthesis. Technical points specializing in foraminal decompression in spondylolisthesis are required for clinical success.

Endoscopic Transforaminal Lumbar Foraminotomy: A Systematic Review and Meta-Analysis

INTRODUCTION

Spinal endoscopic techniques have recently been applied to complex degenerative conditions or failed back surgery syndrome. We performed a systematic review and meta-analysis to assess transforaminal endoscopic lumbar foraminotomy (TELF) outcomes and adverse event rates. We also analyzed the effectiveness of the technique for chronic pain after arthrodesis or previous spinal surgery.

METHODS

Multiple databases were searched for studies published in the English language, involving patients > 18 years old who underwent endoscopic foraminotomy. Outcomes included the rate of patients who showed "excellent" and "good" postoperative improvement, decreased leg pain, and improved Oswestry Disability Index (ODI) scores. Adverse events considered in the analysis included nerve root damage and intraoperative dural tear, the proportion of patients requiring revision surgery or recurrences, and infections.

RESULTS

A total of 14 studies, encompassing 600 patients, were identified. Approximately 85% of patients improved significantly after TELF, without significant differences among different groups (85% vs. 78%, respectively). Mean leg pain decreased an average of 5.2 points, and ODI scores improved by 41.2%. Patients with previous spine surgery or failed back surgery syndrome had higher postoperative leg dysesthesia rates after TELF (14% vs. 1%, respectively).

CONCLUSION

TELF is a useful and safe method to achieve decompression in foraminal stenosis. This technique is indicated in the elderly or patients with comorbidities. Preoperative planning is paramount in determining the foraminal size and endoscope trajectory. A diamond burr is recommended because it has an advantage over the regular endoscopic shaver in bleeding control and complication avoidance.

Original Designed Uniportal-Bichannel Spinal Endoscopic System (UBiSES) for Foraminoplasty in Percutaneous Endoscopic Transforaminal Discectomy

OBJECTIVE

The study introduced uniportal-bichannel spinal endoscopic system (UBiSES) and explored the feasibility of applying UBiSES to conduct lumbar foraminoplasty in percutaneous endoscopic transforaminal discectomy (PETD).

METHODS

This is a cohort study. 36 patients confirmed as L5/S1 lumbar disc herniation (LDH) in our hospital from March, 2019 to November, 2019 were enrolled. 36 patients were divided into two groups named the UBiSES group (n = 18, male: female = 8:10) and the TESSYS group (n = 18, male: female = 10:8). The average age of the UBiSES group and the TESSYS group were 40.94 ± 12.39 years old and 39.78 ± 13.02 years old respectively. PETD via uniportal-bichannel foraminoplasty assisted by UBiSES was adopted on the UBiSES group while PETD via conventional foraminoplasty was performed on the TESSYS group. One experienced surgeon with more than 4000 cases of lumbar surgery performed PETD on all patients. The demographic data, the duration of working cannula placement (minutes), decompression time (minutes), radiation exposure time (seconds), complications, Visual Analogue Scale (VAS), Oswestry Disability Index (ODI) scores and modified MacNab criteria were recorded and analyzed. The magnetic resonance imaging (MRI) and computed tomography (CT) were conducted to evaluate the radiographic improvement.

RESULTS

PETD via lumbar foraminoplasty was successfully performed in all cases. The follow-up points were 3 months, 6 months, and 12 months. The average follow-up period of all patients was 15.78 ± 2.29 months. There was no statistic difference in age (P = 0.81), sex (P = 0.51) and follow-up (P = 0.14) between two groups. The duration of working cannula placement was 19.08 ± 2.30 min in the UBiSES group and 24.90 ± 4.71 min in the TESSYS group and there was significant difference between two groups (P < 0.05). There was no statistic difference in decompression time between the UBiSES group (44.18 ± 5.70 min) and the TESSYS group (47.46 ± 5.96 min) (P = 1.70). The radiation exposure time was 28.00 ± 4.70 s in the UBiSES group and 40.50 ± 5.73 s in the TESSYS group respectively, and has significant difference between two groups (P < 0.05). Furthermore, there was significant different in the duration of working cannula placement and radiation exposure time in male or female between the UBiSES group and the TESSYS group (P < 0.05). For male or female, no difference observed in decompression time and follow-up period between two groups. Postoperative VAS of low back and leg at every follow-up point (1 day, 3 months, 6 months, 12 months) was improved significantly in both groups compared with their preoperative VAS (P < 0.05). The postoperative ODI (3 months, 6 months, 12 months) has decreased significantly in both the UBiSES group and the TESSYS group compared with their preoperative ODI (P < 0.05). 94.44% patients received an excellent or good recovery in the UBiSES group and 88.89% for the TESSYS group. There was no poor result reported in both groups. The radiographic images showed satisfactory foraminoplasty and sufficient decompression of nerve in both groups. No postoperative complications were observed during follow-ups in the UBiSES group. Two patients in the TESSYS group experienced postoperative dysesthesia and the symptom was disappeared in 5 days and 7 days respectively with dexamethasone and neurotrophic drugs treatment.

CONCLUSIONS

The original designed UBiSES could effectively and safely enlarge the foramen with an extensive surgical view and space under full-time and real-time visualization and get satisfactory efficacy.

Percutaneous endoscopic transforaminal discectomy for the treatment of L5-S1 lumbar disc herniation and the influence of iliac crest height on its clinical effects

The present study aimed to explore the clinical effects of percutaneous endoscopic transforaminal discectomy using a transforaminal endoscopic spine system (TESSYS) technique for the treatment of L5-S1 lumbar disc herniation and to analyse the influence of iliac crest height on these clinical effects. The clinical data of 76 patients with L5-S1 single-segment disc herniation treated with TESSYS at The Second Affiliated Hospital and Third Affiliated Hospital of Xi'an Jiaotong University between January and December 2016 were retrospectively analysed. Patients were divided into the following three groups according to the positional relation between the highest point of the iliac crest and the L4 and L5 pedicles in the lateral lumbar, as determined by X-ray: Group I, iliac crest height below the upper edge horizontal line of the L5 pedicle (n=42); group II, iliac crest height between the lower edge horizontal line of the L4 pedicle and the upper edge horizontal line of the L5 pedicle (n=29) and group III, iliac crest height above the lower edge horizontal line of the L4 pedicle (n=5). Changes in the postoperative visual analogue scale (VAS) pain score and Oswestry disability index (ODI) of the lower back and lower limbs were observed, and the effects were compared among the three groups. The mean operating time was 86.5±13.5 min. A single patient experienced cerebrospinal fluid leakage due to a mild tear of the dura mater during the operation, which improved after symptomatic treatment. The same operation was repeated in one patient due to the recurrence of disc herniation. In all patients, the VAS pain score and ODI of the lower back and lower limbs at 1 week and 1, 3 and 12 months following the operation were significantly lower than those before the operation (all P<0.05). Furthermore, the postoperative VAS pain score and ODI of the lower back and lower limbs were poorer in group III (L5-S1 lumbar disc herniation complicated with high iliac crest) than in groups I and II (P<0.05). These results suggested that TESSYS was effective in treating lumbar disc herniation. Whether the iliac crest is higher than the lower edge horizontal line of the L4 pedicle is suggested to be one of the factors influencing the outcome of the operation.

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.

Degenerative central lumbar spinal stenosis: is endoscopic decompression through bilateral transforaminal approach sufficient?

BACKGROUND

At present, few reports of percutaneous endoscopic transforaminal decompression surgery have been reported to solve central lumbar spinal stenosis (CLSS). Is endoscopic decompression through bilateral transforaminal approach decompression sufficient for degenerative CLSS?

METHODS

This retrospective study included 47 cases of CLSS patients who underwent percutaneous endoscopic decompression through bilateral transforaminal approach. Clinical outcomes such as ODI, back and leg VAS, the Macnab criteria were evaluated. Surgical results including operative time, postoperative hospital stay, recurrence, and surgical complications were also studied. Radiologically, lumbar stability was assessed and lumbar dural sac dimension was compared preoperatively and postoperatively.

RESULTS

All 47 patients were followed up. The average follow-up period was 24.5 months. The average operation time was 116 min. The mean VAS of leg and back pain, and the mean ODI improved from 7.81, 2.53, and 77.03% at baseline to a final 1.94 (P = 0.00), 2.47 (P = 0.71), and 19.40% (P = 0.00), respectively. According to the Macnab criteria, 97.9% of patients achieved excellent and good results. There were 2 cases of dural tear and 3 cases of transient postoperative dysthesia. The cross-sectional area of the dural sac was significant enlargement at the last fellow up (74.28 ± 13.08 mm² vs.104.91 ± 12.40 mm², P = 0.00).

CONCLUSIONS

Except for the main pathogenic factors on the dorsal side of the dural sac, percutaneous endoscopic decompression through a bilateral transforaminal approach is sufficient for CLSS. It is a feasible, safe, and clinically effective minimally invasive procedure.

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.

The Evolution of Transforaminal Endoscopic Spine Surgery

Transforaminal endoscopic spine surgery (T-ESS) has become a well-accepted technique. The first attempts at percutaneous discectomy by Kambin and Hijikata opened a new chapter of endoscopic spine surgery. By the last quarter of the twentieth century, spine surgeons had begun to adopt this novel technique. Many researchers helped advance endoscopic spine surgery, but the turning point was the description of a safe transforaminal triangle of safety by Parviz Kambin. Since then, the indications for T-ESS have increased as a result of the description of different surgical approaches such as inside-out, outside-in, and half-and-half. We present a review of crucial historical advancements in T-ESS and also discuss the evolution of endoscopes, the techniques used, development of endoscopic instruments and equipment, transforaminal thoracic endoscopy, transforaminal endoscopic interbody fusions, the growth of extended indications, and the future direction of T-ESS. This review provides a detailed description of key historical moments and a bird's-eye view of the vast scope of T-ESS.

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.

Evolution of endoscopic transforaminal lumbar approach for degenerative lumbar disease

Endoscopic spine surgery has evolved dramatically in last 30 years; with the development of new improved endoscopic optics and instrumentation limitation of endoscopic spine surgery has significantly reduced. The transforaminal approach has been limited in its indications due to its optimized approach and obstacles of bony or neural structures. As the initial transforaminal approach is based on the inside out technique, there were many limitations on the indications. Outside-in approach has been developed to address these limitations. However, the outside-in approach was not free from anatomical obstacles. The mobile outside-in approach technique has advantage of both inside-out and outside-in technique. It is equally safe as inside-out technique and provides an easy handling of structures, while it is equally versatile as outside-in technique in managing different types of disc prolapse such as central, paracentral, foraminal, far lateral, and up and down migration, and in high-canal compromise cases. The mobile outside in technique, however, demands a longer learning curve and beginners need to be patient while learning the technique.

Evolution of Minimally Invasive Lumbar Spine Surgery

Spine surgery has evolved over centuries from first being practiced with Hippocratic boards and ladders to now being able to treat spinal pathologies with minimal tissue invasion. With the advent of new imaging and surgical technologies, spine surgeries can now be performed minimally invasively with smaller incisions, less blood loss, quicker return to daily activities, and increased visualization. Modern minimally invasive procedures include percutaneous pedicle screw fixation techniques and minimally invasive lateral approach for lumbar interbody fusion (i.e., minimally invasive transforaminal lumbar interbody fusion, extreme lateral interbody fusion, oblique lateral interbody fusion) and midline lumbar fusion with cortical bone trajectory screws. Just as evolutions in surgical techniques have helped revolutionize the field of spine surgery, imaging technologies have also contributed significantly. The advent of computer image guidance has allowed spine surgeons to advance their ability to refine surgical techniques, increase the accuracy of spinal hardware placement, and reduce radiation exposure to the operating room staff. As the field of spine surgery looks to the future, many novel technologies are on the horizon, including robotic spine surgery, artificial intelligence, and machine learning to help improve preoperative planning, improve surgical execution, and optimize patient selection to ensure improved postoperative outcomes and patient satisfaction. As more spine surgeons begin incorporating these novel minimally invasive techniques into practice, the field of minimally invasive spine surgery will continue to innovate and evolve over the coming years.

[Short-term effectiveness of percutaneous endoscopic transforaminal bilateral decompression for severe central lumbar spinal stenosis]

Objective

To observe the effectiveness and safety of percutaneous endoscopic transforaminal bilateral decompression for severe central lumbar spinal stenosis.

Methods

A retrospective analysis of 44 patients with single-segment severe central lumbar spinal stenosis with bilateral lower extremity symptoms between October 2015 and December 2017 was performed. Among them, 36 cases underwent bilateral decompression through bilateral transforaminal approach, and 8 cases underwent bilateral decompression through unilateral transforaminal approach. There were 25 males and 19 females, the age ranged from 56 to 89 years with an average of 68.6 years. The disease duration was 5-39 months with an average of 14.5 months. Involved segments: L _{3, 4} in 6 cases, L _{4, 5} in 33 cases, and L ₅, S ₁ in 5 cases. The dural sac cross-sectional area (DSCA) of the MRI was (66.36±8.48) mm ². Morphological grading (MG) classification: 29 cases of grade C, 15 cases of grade D. The visual analogue scale (VAS) score of preoperative low back pain was 2.3±1.0 and the VAS score of lower extremity pain was 7.8±1.2; the Oswestry disability index (ODI) was 77.8±7.3. Postoperative VAS scores, ODI scores, MG classification, and DSCA were recorded and compared with preoperative ones, and clinical outcomes were assessed by using the modified MacNab criteria.

Results

All patients successfully underwent surgery and the wounds healed by first intention. All 44 patients were followed up 13-46 months with an average of 24.8 months. One patient developed postoperative lower extremity paralysis and 1 patient developed a dural tear. There was no infection, recurrence, or revision surgery during the follow-up. Postoperative imaging showed that the central spinal canal was enlarged and the area of the dural sac was significantly increased compared with preoperative one. The VAS score of low back pain was 2.4±0.6 and 2.5±0.8 at 1 month after operation and at last follow-up, showing no significant difference when compared with preoperative scores ( P>0.05). The VAS of lower limb pain was 2.1±0.6 and 2.0±1.1 at 1 month after operation and at last follow-up, which was significantly improved when compared with preoperative scores ( P<0.05); but no significant difference was found between at 1 month after operation and at last follow-up ( P>0.05). At last follow-up, the ODI score was 19.7±6.4, and the DSCA was (104.93±12.56) mm ², which was significantly improved when compared with preoperative values ( P<0.05). The MG classification was also significantly higher than preoperative one ( Z=-5.789, P=0.000). According to the modified MacNab criteria, the results were excellent in 32 cases, good in 9 cases, and fair in 3 cases, with an excellent and good rate of 93.2%.

Conclusion

Percutaneous endoscopic transforaminal bilateral decompression for treating severe central lumbar spinal stenosis has the advantages of less trauma, adequate decompression, and rapid recovery. The short-term effectiveness is good.

Comparison of Clinical Outcomes of Two-Level PELD and Foraminoplasty PELD for Highly Migrated Disc Herniations: A Comparative Study

Objective

The aim of this study is to compare the clinical outcomes of two-level percutaneous endoscopic lumbar discectomy (PELD) and foraminoplasty PELD in treating highly migrated lumbar disc herniations.

Methods

Patients with highly migrated lumbar disc herniations were enrolled from May 2014 to June 2016. Low back pain and leg pain were evaluated by the Visual Analog Scale (VAS), and functional outcomes were assessed with the Oswestry Disability Index (ODI). The satisfaction rate of clinical outcomes was assessed according to the modified MacNab criteria. In addition, the intraoperative duration and postoperative complications were also recorded.

Results

Forty patients, 14 cases in two-level PELD group and 26 cases in foraminoplasty PELD group, were included. The VAS scores of low back pain (P=0.67) and leg pain (P=0.86), as well as the ODI scores (P=0.87), were comparative between two-level PELD and foraminoplasty PELD groups. The satisfaction rate of clinical outcomes based on the modified MacNab criteria in the two-level PELD group was equivalent to that in foraminoplasty PELD group (92.9% versus 92.3%, P=0.92). In addition, the intraoperative duration of two-level PELD group was longer than that of foraminoplasty PELD group (80.2 ± 6.6 min versus 64.1 ± 7.3 min, P < 0.01). The postoperative complications in the two-level PELD group (postoperative dysesthesia: N = 1) were relatively fewer as compared to those in the foraminoplasty PELD group (postoperative dysesthesia: N = 1; recurrence: N = 1; nucleus pulposus residues: N = 1).

Conclusions

Both two-level PELD and foraminoplasty PELD are safe and effective surgical procedures for the patients with highly migrated lumbar disc herniations. Moreover, the two-level PELD technique has merits in reducing the incidence of postoperative nucleus pulposus residue.

Current techniques of endoscopic decompression in spine surgery

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

Percutaneous 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.

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.

Retrospective study of the interlaminar approach for percutaneous endoscopic lumbar discectomy with the guidance of pre-operative magnetic resonance neurography

Background

To measure the direct effects of pre-operative magnetic resonance neurography (MRN), and analyze the procedure and clinical outcomes of the percutaneous endoscopic interlaminar discectomy, in order to demonstrate the feasibility and safety of the interlaminar approach.

Methods

In this study, 127 patients who underwent percutaneous endoscopic lumbar discectomy (PELD) and were followed up by more than 12 months, were retrospectively evaluated. The pre-operative demographic data were collected. In addition, the coronal scan and the reconstruction of the lumbosacral plexus were examined to measure the distance between the nerve root and the dural sac at the coronal plane. Furthermore, the post-operative and pre-operative visual analog scale (VAS) scores and Oswestry Disability Index (ODI) were compared.

Results

The mean and minimum values of distance T between the nerve root and dural sac of L5/S1 to L2/3 on the operation side of the MRN images were all larger than 7.3 mm which is the diameter of the working canal. During the follow-up, VAS and ODI data improved significantly compared with their corresponding pre-operative scores (P<0.01). Regarding the post-operative complications, there were 2 (1.57%) cases of hypesthesia and 3 (2.36%) cases of neuropathic pain, which were transient and alleviated in 3 months. In addition, there was 1 (0.79%) case of intervertebral space infection and 1 (0.79%) dural tear. No relapse of disc herniation and iatrogenic instability occurred by the end of the last follow-up.

Conclusions

The MRN indicates that the incidence of herniated disc impingement increases over the distance between the nerve root and the dural sac, thus making the interlaminar approach more suitable for the treatment of herniation. The procedures and clinical outcomes of the IL-PELD demonstrate the safety and advantages of the interlaminar approach.

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.

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.

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.

Facet Sparing Foraminal Decompression Using the Flexible Shaver Foraminotomy System: Nerve Safety, Pain Relief, and Patient Satisfaction

Background

A number of surgical options exist for decompressing lumbar foraminal stenosis. Flexible shaver foraminotomy is a recent addition to this armamentarium. While the foraminotomy device has been incorporated into clinical practice, the literature on its safety and efficacy remain limited. We aimed to evaluate nerve safety, pain relief, and patient satisfaction in a series of patients treated with the iO-Flex shaver system (Amendia, Inc., Marietta, Georgia).

Methods

Thirty-one consecutive patients with lumbar foraminal stenosis underwent foraminal decompression using the flexible microblade shaver system at 62 neuroforamina. The shavers were inserted into each foramen using an open hemilaminotomy and fluoroscopic guidance. Nerve mapping via mechanomyography (MMG) was used to ensure nerve safety. Perioperative charts were reviewed to find the incidence of neurologic complications and to quantify pain relief. Average office-based follow-up was 5.3 months. A 3-item questionnaire was administered to assess patient satisfaction during late follow-up, which occurred at an average of 21 months.

Results

No planned iO-Flex foraminotomies were aborted. Neurologic complications included transient dysesthetic pain in 1 patient (3.2%, n = 31), and transient numbness in 3 patients (9.7%, n = 31). There were no motor deficits. The composite nerve complication rate was 12.7%. Preoperative visual analog scale scores decreased from a mean of 7.1 (n = 31, standard deviation [SD] 2.0) to a mean of 3.5 (n = 30, SD 2.5). If asked to repeat their decision to do surgery, 81% of patients would redo the procedure. The rate of patient dissatisfaction was 19%.

Conclusions

Decompression of lumbar foramina using the flexible shaver system and MMG nerve mapping is safe and effective, although the short-term sensory complication with this technique may be higher than previously reported. Patient satisfaction with iO-Flex foraminotomy is comparable to reported satisfaction outcomes for traditional lumbar decompression.

Level of Evidence

4.

Delayed Infected Pseudomeningocele After Percutaneous Endoscopic Lumbar Diskectomy

BACKGROUND

Percutaneous endoscopic lumbar diskectomy (PELD) has evolved over the last decades and has become an effective treatment for soft disk herniations. However, while its use increases, newer complications have been discovered.

CASE DESCRIPTION

We present the unique case of a woman who underwent PELD/foraminotomy to treat right-side foraminal disk herniations on L4-5 and L5-S1 in the same procedure. Ten days after surgery, the patient developed fever and severe low back pain radiated down her right leg. Magnetic resonance imaging showed a right pseudomeningocele arising from L4-5 and a nerve root herniated through the dural sac at the same lumbar segment. Blood cultures and fluid culture obtained from pseudomeningocele drainage depicted infection. Specific antibiotics were administrated, direct dura repair under the microscope was performed, and the patient improved symptomatically.

CONCLUSIONS

PELD combined with foraminotomy is a relatively new and skill-demanding surgery which is indicated only in cases where foraminal disk herniation is combined with foraminal stenosis. This surgical strategy requires experience by the endoscopic surgeon to prevent procedure-related complications. Although rare, these complications can lead to increased morbidity.

Isocentric Navigation for the Training of Percutaneous Endoscopic Transforaminal Discectomy: A Feasibility Study

Background

Percutaneous endoscopic transforaminal discectomy (PETD) is usually chosen for lumbar disc herniation due to its obvious advantages such as small incision and absence of nerve or muscular traction. However, learning PETD is a great challenge for inexperienced surgeons.

Objective

The study aimed to investigate whether isocentric navigation would be beneficial in PETD training.

Methods

A total of 117 inexperienced surgeons were trained with PETD at L2/3, L3/4, L4/5, and L5/S1 on the cadavers without (Group A n=58) or with (Group B n=59) isocentric navigation. Puncture times, fluoroscopy times, exposure time, and radiation dose were recorded and analyzed. Questionnaires were conducted before and after the training program.

Result

Isocentric navigation could improve young surgeons' satisfaction with the training program and decrease the puncture times, fluoroscopy times, exposure time, and radiation dose significantly (P<0.001).

Conclusion

Isocentric navigation contributes to the training of PETD and may improve its standardization, homogenization, and generalization.

Transforaminal Endoscopic Decompression for Lumbar Spinal Stenosis: A Novel Surgical Technique and Clinical Outcomes

OBJECTIVE

Transforaminal endoscopic treatment has been reported to be an effective treatment option in patients with lumbar disc herniation. However, it is rarely performed for spinal stenosis because of the limitation of endoscopic working mobility caused by the exiting nerve root and foraminous bony structure. The objective of this study was to describe a novel transforaminal endoscopic decompression technique for spinal stenosis and report the clinical results.

METHODS

From October 2015 to October 2016, 30 consecutive cases were diagnosed as lateral recess stenosis in our institution and underwent transforaminal endoscopic decompression. Visual analog scale (VAS) of back and leg pain and the Oswestry Disability Index (ODI) were measured preoperatively and at follow-up.

RESULTS

The mean ± SD value of preoperative VAS leg pain score was 7.6 ± 1.17. The score improved to 2.2 ± 1.11 at 1 week postoperatively, 1.73 ± 0.96 at 4 weeks postoperatively, and 1.63 ± 0.95 at 26 weeks postoperatively (P < 0.01). The mean ± SD value of the preoperative ODI score was 65.69 ± 14.22. The score improved to 24.29 ± 11.89 at 1 week postoperatively, 21.25 ± 9.25 at 4 weeks postoperatively, and 15.62 ± 10.49 at 26 weeks postoperatively (P < 0.01). There were no patients with postoperative infection, dural tear, delayed neurologic deterioration, or conversion to open surgery.

CONCLUSIONS

Transforaminal endoscopic decompression under local anesthesia could be an effective treatment method for the selected group of patients with spinal stenosis.

Percutaneous Endoscopic Laminotomy with Flavectomy by Uniportal, Unilateral Approach for the Lumbar Canal or Lateral Recess Stenosis

OBJECTIVE

To evaluate clinical feasibility and safety of percutaneous endoscopic decompression by a uniportal, unilateral approach for lumbar canal or lateral recess stenosis.

METHODS

In this retrospective study, the procedure was performed with endoscopic instruments in the same way as conventional microscopic laminotomy and flavectomy. Clinical outcomes (visual analog scale, Oswestry Disability Index, modified MacNab criteria) were evaluated. Surgical outcomes, including operative time, hospital stay, and complications, were recorded.

RESULTS

Decompression was performed in 213 patients (232 lumbar levels) for spinal canal or lateral recess stenosis (unilateral laminotomy, n = 80; bilateral laminotomy, n = 152). Mean follow-up period was 26.45 months. Mean visual analog scale for leg pain, and back pain and mean Oswestry Disability Index improved from 8.24%, 5.35%, and 67.8% at baseline to 1.93% (P < 0.001), 2.05% (P < 0.001), and 17.14% (P < 0.001) at final follow-up. Based on modified MacNab criteria, excellent or good results were obtained in 93.8% of patients. Average operative time was 105.3 ± 56 minutes. In the late period of the learning curve, mean operative time was shortened by two thirds, and mean hospital stay was 2.45 days. There were 12 cases of transient postoperative dysesthesia, 3 cases of motor weakness, and 6 cases of dural tear. No patient had postoperative infection, hematoma, or need for revision surgery for incomplete decompression.

CONCLUSIONS

Percutaneous endoscopic decompression by a uniportal, unilateral approach is a safe, clinically feasible, and effective surgical technique for treatment of lumbar stenosis.

Radiographic Assessment on Magnetic Resonance Imaging after Percutaneous Endoscopic Lumbar Foraminotomy

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

Learning curves of percutaneous endoscopic lumbar discectomy in transforaminal approach at the L4/5 and L5/S1 levels: a comparative study

OBJECTIVES

This study aimed to compare the learning curves of percutaneous endoscopic lumbar discectomy (PELD) in a transforaminal approach at the L4/5 and L5/S1 levels.

METHODS

We retrospectively reviewed the first 60 cases at the L4/5 level (Group I) and the first 60 cases at the L5/S1 level (Group II) of PELD performed by one spine surgeon. The patients were divided into subgroups A, B, and C (Group I: A cases 1-20, B cases 21-40, C cases 41-60; Group II: A cases 1-20, B cases 21-40, C cases 41-60). Operation time was thoroughly analyzed.

RESULTS

Compared with the L4/5 level, the learning curve of transforaminal PELD at the L5/S1 level was flatter. The mean operation times of Groups IA, IB, and IC were (88.75±17.02), (67.75±6.16), and (64.85±7.82) min, respectively. There was a significant difference between Groups A and B (P<0.05), but no significant difference between Groups B and C (P=0.20). The mean operation times of Groups IIA, IIB, and IIC were (117.25±13.62), (109.50±11.20), and (92.15±11.94) min, respectively. There was no significant difference between Groups A and B (P=0.06), but there was a significant difference between Groups B and C (P<0.05). There were 6 cases of postoperative dysesthesia (POD) in Group I and 2 cases in Group IIA (P=0.27). There were 2 cases of residual disc in Group I, and 4 cases in Group II (P=0.67). There were 3 cases of recurrence in Group I, and 2 cases in Group II (P>0.05).

CONCLUSIONS

Compared with the L5/S1 level, the learning curve of PELD in a transforaminal approach at the L4/5 level was steeper, suggesting that the L4/5 level might be easier to master after short-term professional training.

Revision percutaneous endoscopic lumbar discectomy under the local anesthesia for the recurrent lumbar herniated nucleus pulposus in a high class athlete: A case Report

Percutaneous endoscopic discectomy (PED) is a minimally invasive spinal technique and has several advantages compared with open surgery. We describe repeat PED surgery for recurrent herniated nucleus pulposus (HNP). The patient was a 33-year-old handball high level player. Previously, he underwent transforaminal PED under local anesthesia for intracanalicular HNP at L4-5 level about 2 years ago. He could return to his original competitive level. Two years later, he felt low back and right leg pain again when he was playing handball. Magnetic resonance imaging revealed the recurrence of HNP at the same level. We conducted transforaminal PED again using the exact same route as the previous surgery. Although there was a little adhesion around the L5 nerve root, we could easily identify and remove the herniated mass using endoscopic forceps. Immediately after the surgery, the low back and leg pain disappeared. Repeat PED surgery for recurrence of lumbar disc herniation is effective especially for athletes because of the benefits of PED, including surgery under local anesthesia, preservation of normal posterior structures, less postoperative pain, early discharge, and faster return to sports.

Lumbar Scoliosis Combined Lumbar Spinal Stenosis and Herniation Diagnosed Patient Was Treated with "U" Route Transforaminal Percutaneous Endoscopic Lumbar Discectomy

The objective was to report a case of a 63-year-old man with a history of low back pain (LBP) and left leg pain for 2 years, and the symptom became more serious in the past 5 months. The patient was diagnosed with lumbar scoliosis combined with lumbar spinal stenosis (LSS) and lumbar disc herniation (LDH) at the level of L4-5 that was confirmed using Computerized Topography and Magnetic Resonance Imaging. The surgical team preformed a novel technique, “U” route transforaminal percutaneous endoscopic lumbar discectomy (PELD), which led to substantial, long-term success in reduction of pain intensity and disability. After removing the osteophyte mass posterior to the thecal sac at L4-5, the working channel direction was changed to the gap between posterior longitudinal ligament and thecal sac, and we also removed the herniation and osteophyte at L3-4 with “U” route PELD. The patient's symptoms were improved immediately after the surgical intervention; low back pain intensity decreased from preoperative 9 to postoperative 2 on a visual analog scale (VAS) recorded at 1 month postoperatively. The success of the intervention suggests that “U” route PELD may be a feasible alternative to treat lumbar scoliosis with LSS and LDH patients.

Surgical Outcome of Two-Level Transforaminal Percutaneous Endoscopic Lumbar Discectomy for Far-Migrated Disc Herniation

Objective. To describe the two-level percutaneous endoscopic lumbar discectomy (PELD) technique in transforaminal approach for highly migrated disc herniation and investigate its clinical outcomes. Methods. A total of 22 consecutive patients with highly migrated lumbar disc herniation were enrolled for the study from June 2012 to February 2014. Results. There were 12 males and 10 females, with a mean age of 41.1 (range 23–67) years. The mean follow-up period was 18.05 (range 14–33) months. According to the modified MacNab criteria, the clinical outcome at the final follow-up was excellent in 14, good in 6, and fair in 2 patients and the satisfactory rate (excellent and good) was 90.9%. The improvements in VAS and ODI were statistically significant. One patient had recurrent herniation in 18 months after the first surgery and underwent open discectomy. One patient showed symptoms of postoperative dysesthesia (POD), but the POD symptom was transient and partial remission was achieved in two months after conservative treatment. Conclusion. Two-level PELD in transforaminal approach can be a safe and effective procedure for highly migrated disc herniation.

Percutaneous Transpedicular Lumbar Endoscopy: A Case Report

INTRODUCTION

Since Kambin introduced the concept of percutaneous transforaminal disc surgery in 1973, there has been numerous advances in the field of spine endoscopy and the concept of central debulking of the disc has changed to targeted fragmentectomy and disc preservation. The lumbar disc fragments which are down migrated and to the medial aspect of the pedicle are extremely challenging to deal by transforaminal approach even after foraminoplasties and by various other approaches. Therefore most spine surgeons prefer open procedures which requires extensive removal of pars and facet leading to the risk of instability.

AIMS AND OBJECTIVES

To describe a safe and effective technique for lumbar intra-canal high grade down migrated disc herniation, medial to the pedicle by transpedicular endoscopy.

METHODS AND TREATMENT

Two patients underwent percutaneous transpedicular lumbar endoscopy under local anaesthesia for high grade down migrated disc herniation and for discal cyst at the medial aspect of pedicle respectively.

RESULTS

We achieved the complete successful decompression by percutaneous transpedicular lumbar endoscopy.

CONCLUSION

Authors found this technique very promising in complete removal of disc material under direct visualisation for high grade down disc herniations.

Navigation improves the learning curve of transforamimal percutaneous endoscopic lumbar discectomy

PURPOSE

Beginners usually need increased punctures and dozens of fluoroscopy in learning transforamimal percutaneous endoscopic lumbar discectomy (tPELD). Navigator-assisted spinal surgery (NASS) is a novel technique that could induce a definite trajectory. The retrospective study aimed to investigate the impact of a definite trajectory on the learning curve of tPELD.

METHODS

A total of 120 patients with symptomatic lumbar disc herniation who received tPELD between 2012 and 2014. Patients receiving tPELD with NASS technique by one surgeon were regarded as group A, and those receiving conventional methods by another surgeon were regarded as group B. Each group was divided into three subgroups (case 1-20, case 21-40, case 41-60).

RESULTS

The fluoroscopy times were 22.62 ± 3.80 in group A and 34.32 ± 4.78 in group B (P < 0.001). The pre-operative location time was 3.56 ± 0.60 minutes in group A and 5.49 ± 1.48 minutes in group B (P < 0.001). The puncture-channel time was 21.85 ± 4.31 minutes in group A and 34.20 ± 8.88 minutes in group B (P < 0.001). The operation time was 84.62 ± 9.20 minutes in group A and 101.97 ± 14.92 minutes in group B (P < 0.001), and the learning curve of tPELD in group A was steeper than that in group B. No significant differences were detected in patient-reported outcomes, hospital stay, patient satisfaction, and complication rate between the two groups (p > 0.05).

CONCLUSIONS

Definite trajectory significantly reduced the operation time, preoperative location time, puncture-channel time, and fluoroscopy times of tPELD by beginners, and thus reshaped the learning curve of tPELD and minimized the radiation exposure.

The Effect and Feasibility Study of Transforaminal Percutaneous Endoscopic Lumbar Discectomy Via Superior Border of Inferior Pedicle Approach for Down-Migrated Intracanal Disc Herniations

Transforaminal percutaneous endoscopic lumbar discectomy (PELD) is gradually regarded as an effective alternative to posterior open surgery. However, migrated herniations bring a great technical challenge even for experienced surgeons due to the absence of the appropriate approaching guideline. We aimed to describe a safe and effective approaching technique for the removal of down-migrations on the basis of the clinical outcomes and complications compared with the conventional approaching method.A total of 45 patients recommended to single-level PELD with foraminoplasty were randomly divided into 2 groups, group A received foraminoplasty via upper border of inferior pedicle, group B was approached through the common transforaminal route. The clinical outcomes were evaluated by Visual Analog Scale (VAS) for leg pain and Oswestry Disability Index (ODI) scores. Then participants were classified into 2 types of migrations (high-grade and low-grade) based on the extent of migration presented on preoperative magnetic resonance imaging (MRI). The various comparisons between the 2 surgical techniques were analyzed.The postoperative VAS and ODI scores significantly decreased in both of the 2 groups after surgery (P < 0.001). The follow-up continued 1 year. With increasing length of follow-up, the disparities in clinical outcomes between the 2 groups were gradually narrowing and there was no significant difference at the end of follow-up (P = 0.32; P = 0.46). There were no differences in the operation time and duration of hospital stay (P = 0.36; P = 0.08). The highly migration group in group B showed a significant longer operation time (P = 0.02), but the extent of migration did not have a significant influence on the operation time in group A with the modified approach (P = 0.19). There were no apparent approach-related complications in group A during the procedure and follow-up period.Foraminoplastic-PELD via upper border of inferior pedicle can serve as a safe and effective minimally invasive technique for removal of down-migrated herniations. Furthermore, it is essential to identify the radiologic characteristics so as to choose the most appropriate approaching technique.

Percutaneous Transforaminal Lumbar Interbody Fusion (pTLIF) with a Posterolateral Approach for the Treatment of Denegerative Disk Disease: Feasibility and Preliminary Results

BACKGROUND

Interbody fusion by open discectomy is the usual treatment for degenerative disk disease but requires a relatively long recovery period. The transforaminal posterolateral approach is a well-known standard in endoscopic spine surgery that allows direct access to the disk with progressive tissue dilation. The aim of this study was to assess the feasibility of percutaneous transforaminal interbody fusion (pTLIF) with insertion of an expandable or a standard rigid interbody implant for patients with degenerative disk disease with or without spondylolisthesis and for revision surgery.

METHODS

Between 2009 and 2014, the pTLIF procedure was performed in 30 patients. Ten patients underwent insertion of a rigid implant (group A) and the remaining 20 underwent insertion of an expandable titanium interbody implant as the initial procedure (n = 10) (group B) or after failed back surgery (n = 10) (group C). Patient outcomes were scored with visual analogic scale (VAS), Oswestry disability index (ODI) and modified Macnab criteria.

RESULTS

The mean follow-up period was 38 (17) (range 11 to 67) months. The outcome was excellent in 18, good in 10 and fair in 2. No poor results and no major complications were reported. No differences in VAS and ODI scores according to the study group were found. Median postoperative time until hospital discharge was 26 hours (20 to 68 hours). Postoperative values for VAS and ODI scores improved significantly (p<0.05) compared to preoperative data in all study groups.

CONCLUSIONS

These preliminary results have shown the feasibility and efficacy of the pTLIF procedure using a posterolateral approach for the treatment of degenerative disk disease with or without spondylolisthesis up to grade 2 and in revision surgery. No significant differences in outcome were observed between an expandable and a rigid cage. Median postoperative time until hospital discharge was faster compared to standard TLIF (26 hours vs. 9.3 days).

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

Supplemental Digital Content is Available in the Text.

BACKGROUND:

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

OBJECTIVE:

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

METHODS:

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

RESULTS:

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

CONCLUSION:

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

ABBREVIATIONS:

ELF,endoscopic lumbar foraminotomy

ODI, Oswestry Disability Index

VAS, visual analog scale

Transforaminal endoscopic lumbar decompression & foraminoplasty: a 10 year prospective survivability outcome study of the treatment of foraminal stenosis and failed back surgery

Background

Conventional diagnosis between axial and foraminal stenosis is suboptimal and long-term outcomes limited to posterior decompression. Aware state Transforaminal Endoscopic Lumbar Decompression and Foraminoplasty (TELDF) offers a direct aware state means of localizing and treating neuro-claudicant back pain, referred pain and weakness associated with stenosis failing to respond to conventional rehabilitation, pain management or surgery. This prospective survivability study examines the outcomes 10 years after TELDF in patients with foraminal stenosis arising from degeneration or failed back surgery.

Methods

For 10 years prospective data were collected on 114 consecutive patients with multilevel spondylosis and neuro-claudicant back pain, referred pain and weakness with or without failed back surgery whose symptoms had failed to respond to conventional rehabilitation and pain management and who underwent TELDF. The level responsible for the predominant presenting symptoms of foraminal stenosis, determined on clinical grounds, MRI and or CT scans, was confirmed by transforaminal probing and discography. Patients underwent TELDF at the spinal segment at which the predominant presenting symptoms were reproduced. Those that required treatment at an additional segment were excluded. Outcomes were assessed by postal questionnaire with failures being examined by the independent authors using the Visual Analogue Pain Scale (VAPS), the Oswestry Disability Index (ODI) and the Prolo Activity Score.

Results

Cohort integrity was 69%. 79 patients were available for evaluation after removal of the deceased (12), untraceable (17) and decliners (6) from the cohort.

VAP scores improved from a pre-operative mean of 7.3 to 2.4 at year 10. The ODI improved from a mean of 58.5 at baseline to 17.5 at year 10. 72% of reviewed patients fulfilled the definition of an “Excellent” or “Good Clinical Impact” at review using the Spinal Foundation Outcome Score. Based on the Prolo scale, 61 patients (77%) were able to return and continue in full or part-time work or retirement activity post-TELDF. Complications of TELDF were limited to transient nerve irritation, which affected 19% of the cohort for 2 – 4 weeks. TELDF was equally beneficial in those with failed back surgery.

Conclusions

TELDF is a beneficial intervention for the long-term treatment of severely disabled patients with neuro-claudicant symptoms arising from spinal or foraminal stenosis with a dural diameter of more than 3mm, who have failed to respond to conventional rehabilitation or chronic pain management. It results in considerable improvements in symptoms and function sustained 10 years later despite co-morbidity, ageing or the presence of failed back surgery.

Clinical Relevance

The long term outcome of TELDF in severely disabled patients with neuro-claudicant symptoms arising from foraminal stenosis which had failed to respond to conventional rehabilitation, surgery or chronic pain management suggests that foraminal pathology is a major cause of lumbar axial and referred pain and that TELDF should be offered as primary treatment for these conditions even in the elderly and infirm. The application of TELDF at multiple levels may further widen the benefits of this technique.