Transforaminal Endoscopic Decompression for Lumbar Lateral Recess Stenosis: An Advanced Surgical Technique and Clinical Outcomes

Endoscopic Treatment of Lumbar Degenerative Disc Disease: A Narrative Review of Full-Endoscopic and Unilateral Biportal Endoscopic Spine Surgery

BACKGROUND

Degenerative lumbar spine disease is the leading cause of disability and work absenteeism worldwide. Lumbar microdiscectomy became the standard treatment for herniated discs and stenotic disease. With the evolution of different techniques, endoscopic spinal surgery emerged to minimize the surgical footprint while providing at least non-inferior results. Currently, two different types of endoscopic spine procedures are dominating the surgical scenario: "Full-Endoscopic" (FE) and Unilateral Biportal Endoscopic" (UBE) Spine Surgery. The aim of this study is to describe and analyze their indications, their technical characteristicswithitsadvantagesanddisadvantagesofbothtechniquesandtheirfuture trends.

METHODS

We performed a narrative review of the most relevant articles published up to August 2023 through a Pub Med search. The search terms " FE Spine Surgery" and " UBE Spine Surgery" were used. The articles selected, were independently reviewed by 3 authors and 55 full text articles were reviewed.

RESULTS

The FE and UBE Spine Surgery techniques were described. The FE technique is performed with a monoportal access under constant saline irrigation. The FE comprises the transforaminal and the interlaminar approaches, and the indication depends from the pathology to treat, and still remains controversial. UBE can approach also the spine from a posterior, postero lateral,and para spinal route. It uses two different ports addressed to a target with continuous irrigation. The process of establishing these two portals is called triangulation.

CONCLUSIONS

FE and UBE spine surgery have demonstrated outcomes comparable to open surgery, minimizing complications and surgical footprint.

Transforaminal Full-Endoscopic Ventral Facetectomy: Midterm Results and Factors Associated with Poor Surgical Outcomes

BACKGROUND

 Full-endoscopic spine surgery (FESS) is a well-established procedure for herniated nucleus pulposus. It is a minimally invasive surgery that can be performed under local anesthesia through only an 8-mm skin incision. With improvements in surgical equipment such as high-speed drills, the indications for FESS have expanded to include lumbar spinal stenosis (LSS). We perform a transforaminal full-endoscopic ventral facetectomy (TF-FEVF) for unilateral nerve root-type lateral recess stenosis (LRS) using a transforaminal approach under local anesthesia.The aim of this study was to examine the postoperative results of TF-FEVF for LRS and to identify factors associated with poor surgical outcomes. 85 patients who underwent TF-FEVF for LRS under local anesthesia. Clinical outcomes were determined by visual analog scale (VAS) and the modified MacNab criteria. Evaluation was performed using magnetic resonance imaging (MRI), computed tomography (CT), and flexion-extension radiographs.

METHODS

 This study involved 85 patients (47 males and 38 females) who underwent TF-FEVF for LRS. The mean age was 70.5 years and the mean follow-up duration was 14.8 months. Data were collected on sex, age, level of operation, diagnosis, history of spine surgery at the same level, and duration of follow-up. The diagnosis was categorized as LSS with or without disk bulging. Clinical evaluation was performed using the VAS and modified MacNab criteria. MRI was used to evaluate the degree of disk degeneration, vertebral endplate degeneration, disk height, thickening of the ligamentum flavum, and stenosis. Bony stenosis was evaluated using CT. Sagittal translation and sagittal angulation were also measured by flexion-extension radiographs, and the Cobb angle was measured using a standing front view radiograph. All variables were compared between patients with excellent/good outcomes (E/G group) and those with fair/poor outcomes (F/P group) using the modified MacNab criteria.

RESULTS

 Postoperative VAS showed that leg pain decreased from 59.0 ± 28.6 preoperatively to 17.9 ± 27.2 at the final follow-up (p < 0.01) and that lower back pain also decreased from 60.7 ± 26.6 preoperatively to 27.3 ± 28.6 at final follow-up (p < 0.01). According to the modified MacNab criteria, the results during the final follow-up were excellent in 39 cases, good in 21 cases, fair in 13 cases, and poor in 12 cases. There were no significant differences in sex, age, diagnosis, history of spine surgery, and duration of follow-up periods between the 60 cases (70.6%) in the E/G group and the 25 cases (29.4%) in the F/P group. Imaging evaluation revealed statistically significant differences between the E/G group and the F/P group in intervertebral angle flexion (3.2 vs. 0.4 degrees; p < 0.05), sagittal angulation (4.3 vs. 8.1 degrees; p < 0.05), slip in flexion (0.9 vs. 2.8 mm; p < 0.05), sagittal translation (0.7 vs. 1.6 mm; p < 0.05), and Cobb angle (-0.5 vs. -1.9 degrees; p < 0.05).

CONCLUSION

 Midterm results of TF-FEVF were generally favorable; factors contributing to good or poor TF-FEVF outcomes were large sagittal angulation, large sagittal translation, and concave side.

Transforaminal Endoscopic Lumbar Lateral Recess Decompression for Octogenarian Patients

The incidence of radiculopathy due to lumbar spinal stenosis has been on the increase in the aging population. However, patients aged ≥ 80 years hesitate to undergo conventional open surgery under general anesthesia because of the risk of postoperative morbidity and adverse events. Therefore, less invasive surgical alternatives are required for the elderly or medically handicapped patients. Transforaminal endoscopic lumbar lateral recess decompression (TELLRD) may be helpful for those patients. This study aimed to demonstrate the efficacy of TELLRD for treating radiculopathy in octogenarian patients. A total of 21 consecutive octogenarian patients with lumbar foraminal stenosis underwent TELLRD between January 2017 and January 2021. The inclusion criterion was unilateral radiculopathy, which stemmed from lumbar lateral recess stenosis. The pain source was verified using imaging studies and selective nerve blocks. Full-scale lateral canal decompression was performed using a percutaneous transforaminal endoscopic approach under local anesthesia. We found the pain scores and functional status improved significantly during the 24-month follow-up period. The clinical improvement rate was 95.24% (20 of 21 patients) with no systemic complication. In conclusion, endoscopic lateral recess decompression via the transforaminal approach is practical for octogenarian patients.

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.

Development of an Endoscopic Spine Surgery Program: Overview and Basic Considerations for Implementation

Endoscopic spine surgery (ESS) is an innovative technique allowing for minimally invasive, direct visualization of spinal abnormalities. The growth of ESS in the United States has been stunted by high start-up costs, low reimbursement rates, and the steep learning curve associated with mastering endoscopic techniques. Hergrae, we describe the current state and future direction of ESS and provide key action items for ESS program implementation.

Awake transforaminal endoscopic lumbar discectomy in an ambulatory surgery center: early clinical outcomes and complications of 100 patients

PURPOSE

Transforaminal endoscopic discectomy has been found to have equivalent outcomes to traditional discectomy techniques. Controversy exists concerning whether this should be performed under general anesthetic with neuromonitoring or can be safely performed on awake patients without neuromonitoring. This study aimed to evaluate the safety and effectiveness of awake transforaminal endoscopic discectomy in an ambulatory setting.

METHODS

100 consecutive patients with lumbar disc herniations treated with transforaminal endoscopic discectomy by a single surgeon were enrolled in the study. All procedures were performed under conscious sedation with local anesthetic. Preoperative and postoperative visual analog scale (VAS) scores were recorded and compared. Time spent in recovery prior to discharge home and complications were also recorded.

RESULTS

Average VAS score improved from a mean of 6.85 to 0.74 (median 7 to 0) immediately postoperatively. The average time spent in Post Anesthesia Care Unit (PACU) prior to discharge was 56.7 min. Average VAS score at 2 weeks was 3.07 (median 2.5). Complication rates were commensurate with published results in the literature. The most common complication was radiculitis, which appears to be more likely with foraminal/extraforaminal herniations at a rate of 20.7%, versus 2.6% for central/paracentral herniations. There were no cases that required conversion to general anesthetic or transfer to a hospital and no permanent nerve injuries in this cohort.

CONCLUSIONS

Endoscopic discectomy can safely and successfully be performed in an ambulatory surgery center under conscious sedation and local anesthetic without neuromonitoring. This procedure leads to rapid recovery in the PACU and significantly improved VAS scores postoperatively.

LEVEL OF EVIDENCE

Level IV.

Full-endoscopic foraminotomy in low-grade degenerative and isthmic spondylolisthesis: a patient-specific tailored approach

PURPOSE

To describe the surgical technique and methodology to successfully plan and execute an endoscopic foraminotomy in patients with isthmic or degenerative spondylolisthesis, according to each patient's unique characteristics.

METHODS

Thirty patients with degenerative or isthmic spondylolisthesis (SL) with radicular symptoms were included from March 2019 to September 2022. Treating physician registered patients' baseline and imaging characteristics, as well as preoperative back pain VAS, leg pain VAS and ODI. Subsequently, authors treated the included patients with an endoscopic foraminotomy according to a "patient-specific" tailored approach.

RESULTS

Nineteen patients (63.33%) had isthmic SL and 11 patients (36.67%) had degenerative SL. 75.86% of the cases had a Meyerding Grade 1 listhesis. One of the transforaminal foraminotomies with lateral recess decompression in degenerative SL had to be aborted because of intense osseous bleeding. Of the remaining 29 patients, one patient experienced recurrence of the sciatica pain that required subsequent reintervention and fusion. No other intraoperative or post-operative complications were observed. None of the patients developed post-operative dysesthesia. In 86.67% of the patients, the foraminotomy was implemented using a transforaminal approach. In the remaining 13.33% of the cases, an interlaminar contralateral approach was used. Lateral recess decompression was performed in half of the cases. Mean follow-up time was 12.69 months, reaching a maximum of 40 months in some patients. Outcome variables such as VAS for leg and back pain, as well as ODI, showed statistically significant reduction since the 3-month follow-up visit.

CONCLUSION

In the presented case series, endoscopic foraminotomy achieved satisfactory outcomes without sacrificing segmental stability. The proposed patient-specific "tailored" approach allowed to successfully design and execute the surgical strategy to perform an endoscopic foraminotomy through transforaminal or interlaminar contralateral approaches.

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.

Is Decompression and Partial Discectomy Advantageous Over Decompression Alone in Microendoscopic Decompression Of Monosegmental Unilateral Lumbar Recess Stenosis?

BACKGROUND

Endoscopic techniques are well accepted as surgical technique for decompression of lumbar lateral recess stenosis (LRS). It is uncertain if there is a difference in clinical outcome for decompression alone (DA) or decompression with partial discectomy (DPD) for the treatment of LRS.

METHODS

All files of patients who underwent an endoscopic procedure for lumbar LRS were identified from a prospectively collected database. Preoperative magnetic resonance imaging and endoscopic video were analyzed with special focus on the technique of nerve root decompression. Clinical outcome was assessed via a personal examination, a standardized questionnaire including the numeric rating scale (NRS) for leg and back pain, the Oswestry disability index (ODI), and the modified MacNab criteria to assess functional outcome and clinical success.

RESULTS

Sixty-six patients were identified of which 57 attended for evaluation (86.4%). DA was performed in 15 (26.3%) patients and DPD in 42 patients (73.7%). The mean follow-up was 45.0 months (range: 16-82 months). Fifty-two patients reported to be free of leg pain (91.1%), 42 patients had no noticeable back pain (73.7%), 49 patients had full muscle strength (85.9%), and 48 patients had no sensory disturbance (84.2%). The mean NRS for leg pain was 1, the mean NRS for back pain was 2, mean ODI was 16% (range: 0%-60%). Clinical success was noted in 49 patients (85.9%) and it was significantly higher for patients following DPD (P = .024). The overall repeat procedure rate was 12% with reoperation rate at the index segment in 10.5% of cases. There were no significant differences with respect to leg and back pain, ODI, and reoperation between both groups.

CONCLUSION

Microendoscopic DPD of LRS achieves a 92% clinical success rate which is significantly higher compared to 67% clinical success achieved by DA. There was no significant difference for the rate of reoperation, leg and back pain, and ODI.

LEVEL OF EVIDENCE

4.

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.

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

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

The evolution of interlaminar endoscopic spine surgery

Due to the aging population, patients required spinal surgery for degenerative spondylopathy is increasing. With the advent of surgical instruments and techniques, minimally invasive spine surgery is prevalent worldwide. Besides microscopic techniques, endoscopic spine surgery has gotten attention gradually in this surgical field for the past two decades. There are two essential approaches developed currently, including transforaminal and interlaminar approach. These innovative equipment and skills promote the progression of endoscopic surgery from discectomy to decompression of spinal stenosis. Meanwhile, they also opened up the application of endoscopic surgery in a complicated situation. From the perspective of emerging technologies and techniques, the authors will review the evolution and describe the prospects of the interlaminar endoscopic spine surgery (IESS).

Efficacy and safety of percutaneous endoscopic decompression via transforaminal and interlaminar approaches for lumbar spine stenosis: Protocol for a systematic review and meta-analysis

BACKGROUND

Lumbar spinal stenosis (LSS) is a common and frequently-occurring disease in the elderly. Percutaneous endoscopic decompression (PED) has become the first choice for the treatment of LSS because of its small wound, mild pain and rapid recovery. The surgical approaches are mainly divided into percutaneous interlaminar approach and transforaminal approach. However, these two surgical approaches have their own advantages, disadvantages and indications. Hence, the present study aims to synthesize the available direct and indirect evidence of transforaminal approach and interlaminar approach to prove their respective advantages and disadvantages.

METHODS

The following databases will be searched: Cochrane Library, PubMed, Web of Science, Embase, CNKI, Wanfang data, and China Biomedical Literature Database (CBM). The search dates will be set from the inception to November 2019. Two researchers independently screened the literature, extracted the data and assessed the risk of bias in the included studies. The efficacy outcomes including: Back and Leg Visual Analog Scale (VAS) score, the MacNab criteria, the Oswestry Disability Index (ODI) and Japanese Orthopedic Association (JOA) score. The safety outcomes including: incidence of complications (dura tear, incomplete decompression, reoperation, etc.). The meta-analysis will be conducted using Stata 12.0 software. Grading of Recommendations Assessment, Development and Evaluation (GRADE) will be used to assess evidence quality.

RESULTS

The results of this meta-analysis will be published in a peer-reviewed journal.

CONCLUSION

The meta-analysis will provide a comprehensive summary of the evidence for 2 approaches to PED in patients with LSS.

PROTOCOL REGISTRATION NUMBER

CRD42019128080.

[Percutaneous endoscopic transforaminal unilateral decompression for treatment of lumbar spinal stenosis and observational study of non-surgical lower extremity symptoms]

Objective

To summarize the efficacy of percutaneous endoscopic transforaminal unilateral decompression for the treatment of lumbar spinal stenosis, and to investigate the incidence and possible reasons for lower extremity symptoms of non-surgical side after surgery.

Methods

The clinical data of 46 patients who underwent percutaneous endoscopic transforaminal unilateral decompression for lumbar lateral recess stenosis between February 2016 and March 2018 were retrospectively analysed. There were 22 males and 24 females with an average age of 56.9 years (range, 21-90 years). The disease duration was 6 months to 12 years (mean, 4.8 years). There were 37 cases of single-segment lumbar lateral recess stenosis and 9 cases of multi-segment stenosis. All patients underwent single-segment surgery, including 2 cases of L _{3, 4}, 35 cases of L _{4, 5}, and 9 cases of L ₅, S ₁. For patients with multi-segment lumbar lateral recess stenosis, the single segment consistent with radicular symptom was selected for surgery. The visual analogue scale (VAS) scores of low back pain and sciatica and Oswestry disability index (ODI) scores were recorded preoperatively and at last follow-up to evaluate the relief of symptoms. Postoperative symptoms on non-surgical side of lower extremity including new or aggravated radiation pain and numbness were recorded. The surgical effectiveness was evaluated according to modified MacNab score at last follow-up.

Results

All the 46 patients underwent successful operations without postoperative complications such as wound infection, permanent nerve root injury, and deep vein thrombosis. The patients were followed up 12-37 months (mean, 23.8 months). Four patients suffered from radioactive pain and numbness for the non-surgical side of lower extremities at 1-3 months postoperatively, and the symptoms were improved after conservative treatment without revision surgery. VAS scores of low back pain and sciatica and the ODI scores were significantly improved at last follow-up when compared with preoperative ones ( P<0.01). According to the criteria of modified MacNab scores, 25 cases were excellent, 17 cases were good, 3 cases were fair, and 1 case was poor. The excellent and good rate was 91.3%.

Conclusion

Percutaneous endoscopic transforaminal unilateral decompression for lumbar spinal stenosis would be able to relieve pain effectively and achieve good results. Lower extremity symptoms of non-surgical side may be observed postoperatively. Although the symptoms can be relieved by conservative treatment, further investigation should be carried out for the long-term result of those cases.