Transforaminal Unilateral Biportal Endoscopic Spinal Surgery for Extraforaminal Lumbar Disc Herniation: A Retrospective Observational Study

OBJECTIVE

Biportal endoscopic spinal surgery (BESS) is recommended as a safer and less destructive option for lumbar disc herniations. However, limited data exist on clinical outcomes for extraforaminal lumbar disc herniation (ELDH) surgery. This retrospective study presents our preliminary experience with transforaminal unilateral BESS for ELDH.

METHODS

Patients with lumbar radiculopathy refractory to conservative treatment, diagnosed with ELDH by magnetic resonance imaging, and treated with transforaminal unilateral BESS in 2021-2023 in 2 institutions in Taiwan were eligible for inclusion. Those with lumbar spondylolisthesis grade 2 or more with segmental instability, history of drug abuse or psychiatric diseases, or with a follow-up duration <1 year were excluded. Primary outcomes included visual analog scale for pain, assessed at 1 week, 1 month, 6 months, and 1 year using generalized estimating equations analysis; success and satisfaction of BESS graded by the Macnab criteria; and perioperative complications. Secondary outcomes were operative time and hospital length of stay.

RESULTS

Seventeen patients were included in the analysis, with a mean age of 65.8 years; 11 (64.7%) were males and 15 (88.2%) had no prior lumbar spine surgery. mean operative time was 107.9 minutes, and length of stay was 3.5 days. Graded by Macnab criteria, 16 (94.1%) of patients had good to excellent outcomes. Only 1 patient experienced complications. No recurrence/reoperation was observed. Generalized estimating equations analysis showed that postoperative visual analog scale scores decreased significantly at 1 week (adjusted Beta [aBeta] = -5.47, standard error: 0.29, P < 0.001), 1 month (aBeta = -5.82), 6 months (aBeta = -5.88), and 1 year (aBeta = -6.29).

CONCLUSIONS

Transforaminal unilateral BESS is an alternative and feasible method for treating ELDH, producing good surgical outcomes with few complications and sustaining pain improvement. Future studies with larger patient numbers and comparisons between BESS and other minimally invasive techniques for ELDH are warranted.

Percutaneous endoscopic transforaminal vs. interlaminar discectomy for L5-S1 lumbar disc herniation: a retrospective propensity score matching study

OBJECTIVE

Percutaneous endoscopic lumbar discectomy (PELD) is a safe and effective minimally invasive surgery for treating lumbar disc herniation (LDH); however, the comparative clinical efficacy of percutaneous endoscopic transforaminal discectomy (PETD) and percutaneous endoscopic interlaminar discectomy (PEID) in treating L5-S1 LDH remains unclear. This study compared the clinical advantages of PEID and PETD for treating L5-S1 LDH.

METHODS

This was a single-centre retrospective study analysing clinical data from 120 patients with L5-S1 LDH between February 2016 and May 2020. Propensity score matching (PSM) was used to adjust for imbalanced confounding variables between the two groups. Perioperative data were recorded, and clinical outcomes, including functional scores and imaging data, were compared between groups. Functional scores included visual analogue scale (VAS) for back and leg pain, Oswestry disability index (ODI), and modified MacNab criteria. Imaging data included disc height index (DHI), ratio of greyscale (RVG), and range of motion (ROM) of the responsible segment.

RESULTS

After PSM, 78 patients were included in the study, and all covariates were well balanced between the two groups. In the matched patients, the PEID group showed significantly shorter surgical time (65.41 ± 5.05 vs. 84.08 ± 5.12 min) and lower frequency of fluoroscopy (2.93 ± 0.63 vs. 11.56 ± 1.54) compared with the PETD group (P < 0.001). There were no statistically significant differences in intraoperative blood loss, postoperative hospital stay, total incision length, and incidence of complications between the two groups (P > 0.05). After surgery, both groups showed significant improvement in back and leg pain based on VAS and ODI scores (P < 0.05). There were no statistically significant differences in clinical functional scores and imaging data between the two groups at various time points after surgery (P > 0.05). According to the modified MacNab criteria, the excellent and good rates in the PEID group and PETD group were 91.89% and 89.19%, respectively, with no statistically significant difference (P > 0.05).

CONCLUSION

PEID and PETD have similar clinical efficacy in treating L5-S1 disc herniation. However, PEID is superior to PETD in reducing operation time and frequency of fluoroscopy.

Comparative analysis of patient-reported outcomes after percutaneous endoscopic lumbar discectomy between transforaminal and interlaminar approach: a minimum two year follow-up

PURPOSE

Percutaneous endoscopic lumbar discectomy has been increasingly used in the treatment of lumbar disc herniation. However, there is no consensus on which method would be more effective between the transforaminal and interlaminar approach.

OBJECTIVE

To compare clinical outcomes, patient satisfaction rate, reoperation rate, and residual symptoms between percutaneous endoscopic transforaminal discectomy (PETD) and percutaneous endoscopic interlaminar discectomy (PEID).

STUDY DESIGN

A comparative, retrospective, controlled trial.

SETTING

The study was conducted at the Department of Orthopaedics at a local hospital.

METHODS

From January 2015 to September 2020, consecutive patients who underwent PETD or PEID treatment for lumbar disk herniation (LDH) at the L5/S1 level in our department were retrospectively collected. Baseline data including age, gender, body mass index (BMI), smoking status, alcohol drinking, clinical symptoms, physical examination, and radiographic characteristics were documented. During the two to three year follow-up periods, patients were evaluated clinically, including clinical outcomes assessed by the visual analog score (VAS), patient satisfaction rates assessed by the North American Spine Society patient satisfaction index (PSI), recurrent rate, and residual symptoms.

RESULTS

A total of 113 patients with PELD in our department were included in the current study, with 65 patients in the PETD group and 48 in the PEID group. Demographic characteristics including age, gender, height, BMI, cigarette smoking, alcohol consumption status, and diabetes did not show any significant difference between the PETD and PEID groups. The VAS scores of the two groups were similar preoperatively, but the postoperative VAS score of the PEID group was lower than that of the PETD group. There were 90.8% of patients in the PETD group who were satisfied with the operation compared to 97.9% in the PEID group. The recurrence rate did not differ between groups, with three patients in both groups. Regarding residual symptoms, there were more patients in the PETD group who reported low back pain during the follow-up periods.

LIMITATION

The main limitations are that all patients were operated by the same surgical team from the same site, and there was a lack of multicenter data.

CONCLUSION

Both PETD and PEID have satisfactory patient-reported outcomes for treating LDH. The PEID procedure results in fewer low back pain residual symptoms than the PELD procedure.

Optimal approach for total endoscopic discectomy and its effect on lumbar and leg function in patients with disc herniation

BACKGROUND

Disc herniation (DH) is a fragment of the disc nucleus that is pushed out of the annulus into the spinal canal due to a tear or rupture in the annulus. It is a common cause of lumbar and leg pains. Substantial advancements have been made to determine the cause of DH and to ensure accurate diagnosis, imaging, and treatment of this condition. Total endoscopic discectomy is an alternative surgical technique that is less invasive.

AIM

To study the optimal approach for a total endoscopic discectomy and its influence on lumbar and leg function in DH patients.

METHODS

This prospective study enrolled 120 patients with lumbar DH who were treated in our hospital from February 2018 to January 2021. All patients were randomly divided into the following two groups: The observation group, comprising 62 patients who underwent surgery using the interlaminar approach, and the control group, comprising 58 patients who were operated through the foramina approach. The treatment effects, perioperative indicators, functional recovery, pain, and quality of life were compared between the two groups.

RESULTS

The treatment effect in the observation group (93.55%) was significantly better than that in the control group (77.59%). There was no difference in the operative time and intraoperative blood loss amount between the two groups (P > 0.05). The hospitalization time of the observation group (4.34 ± 1.33 d) was significantly shorter than that of the control group (5.38 ± 1.57 days) (P < 0.05). The Japanese Orthopaedic Association and Oswestry Disability Index scores decreased significantly in both groups after treatment, but the scores were lower in the observation group than in the control group. The visual analog scale scores of the lower back and legs of the two groups were significantly reduced after treatment, but scores were lower in the observation group (2.18 ± 0.88 in the lower back and 1.42 ± 0.50 in the leg) than in the control group (3.53 ± 0.50 in the lower back and 2.21 ± 0.52 in the leg). A short form of the Arthritis Impact Measurement Scales 2 measurement scale (AIMS2-SF) score and Barthel index of the lower back of the two groups increased significantly after treatment, with the observation group having a significantly higher AIMS2-SF score (95.16 ± 1.74) and Barthel index (97.29 ± 1.75) than the control group (84.95 ± 2.14 and 89.16 ± 2.71, respectively) (P < 0.05).

CONCLUSION

Through total endoscopic discectomy with the interlaminar approach, the degree of pain in the waist and leg was reduced, and the lumbar function considerably recovered.

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.

Full Endoscopic Repair of Spontaneous Ventral Cerebrospinal Fluid Leaks in the Spine: Systematic Review of Surgical Treatment Options and Illustrative Case

BACKGROUND

Spontaneous spinal cerebrospinal fluid (CSF) leaks are a rare entity that can lead to intracranial hypotension and associated headaches, meningismus, and patient debility. Surgical treatment may be necessary for patients who do not respond to conservative management. Surgical repair of CSF leaks located in the ventral thoracic spine traditionally require an invasive, open approach.

METHODS

We describe the case of a patient with a ventral thoracic spontaneous spinal CSF leak associated with a ventral bony osteophyte successfully treated with spinal endoscopy. We also provide a systematic review of the literature to better understand outcomes of this approach.

RESULTS

A total of 55 patients were included in the systematic review. The study designs found in the literature review included case reports (66.7%), retrospective cohorts (22.2%), and prospective cohorts (11.1%). Of the studies reporting data, 50% of studies stated they used an open posterior approach to the dural defect, while 37.5% reported using an open anterior approach to the pathology. Only 1 (12.5%) study reported using an endoscope. Most studies (62.5%) used primary closure of the dura in their technique, while 37.5% reported using a local tissue graft (fat or muscle) or a dural sealant for their closure technique, and 25% of studies reported using a dural substitute for their closure technique. Overall mean clinical follow-up was 19.8 months.

CONCLUSIONS

The endoscopic approach described here for treatment of this rare entity allows for removal of bony spicules/osteophytes and dural repair without the morbidity associated with traditional open dorsolateral or ventrolateral approaches.

A Novel Transforaminal Approach to Presacral Abscess

BACKGROUND

Presacral abscess is a common disease in the developing countries. Treatments include minimally invasive percutaneous drainage and open surgical debridement. Percutaneous drainage under computed tomography (CT) guidance has been recommended by the American College of Radiology as a good alternative to surgical drainage before elective surgical treatment. Because of the many anatomic obstacles, the presacral space can be one of the most difficult locations to access. There are several reported access routes like transabdominal, transgluteal, transvaginal, transperineal, transanal, precoccygeal, transpedicular, and so on. We introduce a novel approach, the trans-sacral-foramen approach, to drain presacral abscess under CT guidance.

METHODS

A 47-year-old woman who had lumbar laminectomy debridement for epidural abscess was diagnosed with residual presacral abscess. She was placed in the prone position. One-step technique was applied. Intermittent CT scans were obtained during drainage catheter (8F) advancement into the sacral posterior foramen. The stylet was withdrawn and an approximately 60° angle for catheter trajectory was used to best reach the sacral anterior foramen due to the inherent pelvic tilt. When the catheter tip reached the presacral abscess, the abscess cavity was aspirated with a syringe, pus was drained, and catheter was fixed to skin. Sensitive antibiotics were administered.

RESULTS

After 2 weeks magnetic resonance imaging (MRI) showed significant reduced abscess and the catheters were removed. At 18-month follow-up, MRI showed intervertebral fusion at the lumbosacral segment.

CONCLUSIONS

Trans-sacral-foramen approach is the shortest path to reach the presacral abscess. The approach is easier and safer than the others for patients with indication.

The Endoscopic Trans-Superior Articular Process Approach: A Novel Minimally Invasive Surgical Corridor to the Lateral Recess

BACKGROUND

Transforaminal approaches to the lumbar spine are typically performed utilizing Kambin's triangle as approach corridor; however, degenerative changes can distort anatomy and expose the exiting nerve root to inadvertent injury.

OBJECTIVE

To describe the surgical technique of a novel full-endoscopic approach to access the lateral recess and report clinical outcomes.

METHODS

The trans-superior articular process (SAP) approach involves partial resection of the SAP, allowing access to the lateral recess both ventral and dorsal to the traversing nerve root. A retrospective review of 40 patients who had undergone a trans-SAP approach for decompression of lateral recess pathology was conducted. Outcomes were measured using visual analog scores (VAS) and Oswestry Disability Index (ODI) at 2 wk, 3 mo, and at last follow-up.

RESULTS

At a mean follow-up of 24 mo, patients experienced statistically significant improvement of the VAS for ipsilateral leg pain, VAS for back pain, and ODI when comparing preoperative values to all postoperative time points. The percentage of patients reaching a minimally clinically important difference for VAS leg pain and ODI was approximately 90% and 88%, respectively. The complication profile was favorable with no dural tears and no postoperative motor or sensory deficits. One patient required revision, with a total reoperation rate of 3%.

CONCLUSION

The trans-SAP approach is a novel approach that utilizes a safe surgical corridor via the SAP to access lateral recess pathology. Our initial clinical experience suggests that the trans-SAP approach allows for treatment of lateral recess and foraminal pathology with low complication rates.

Percutaneous Endoscopic Lumbar Discectomy via Transforaminal Approach Combined with Interlaminar Approach for L4/5 and L5/S1 Two-Level Disc Herniation

Objective

The purpose of the present study was to discuss a new surgical strategy that combines percutaneous endoscopic transforaminal discectomy (PETD) with percutaneous endoscopic interlaminar discectomy (PEID) for L4/5 and L5/S1 two‐level disc herniation.

Methods

This was a retrospective study. A total of 19 patients with L4/5 and L5/S1 two‐level lumbar disc herniation (LDH) who underwent percutaneous endoscopic lumbar discectomy (PELD) in our hospital from January 2015 to June 2016 were retrospectively examined. The average age of these 19 patients was 42.21 ± 14.88 years old, including 12 men and 7 women. One experienced surgeon who had carried out more than 3000 lumbar surgeries performed PELD for these patients. During the PELD surgery, the transforaminal approach was adopted for L4/5 level disc herniation and the interlaminar approach was adopted for L5/S1 level disc herniation. The demographic data, operation time (min), fluoroscopy times, hospital stay (days), and complications were recorded and analyzed. The visual analogue scale (VAS), Oswestry disability index (ODI) scores, and the modified MacNab criteria were used to evaluate the surgical outcomes. MRI was conducted to evaluate the radiographic improvement.

Results

All patients underwent PELD via the transforaminal approach combined with the interlaminar approach successfully and achieved satisfactory efficacy. The follow‐up points were 3, 12, and 18 months. The average hospital stay (days) and the average follow up (months) were 3.32 ± 0.98 and 18.63 ± 3.84, respectively. The operation time and fluoroscopy times were 85.79 ± 12.90 min and 39.05 ± 4.59 times, respectively. The fluoroscopy times (frequency) for L4/5 and L5/S1 were 26.95 ± 6.41 and 12.11 ± 3.49 (t = 7.00, P < 0.05). Furthermore, there was no significant difference for fluoroscopy times between male and female patients (t = 0.89, P = 0.99). The preoperative back pain (VAS‐Back) and the last follow‐up VAS‐Back were 5.58 ± 2.01 and 2.37 ± 1.01, respectively (t = 7.14, P < 0.05). The preoperative leg pain (VAS‐Leg) and the last follow‐up VAS‐Leg were 7.00 ± 1.56 and 1.63 ± 1.01, respectively (t = 20.97, P < 0.05). There were significant differences between preoperative VAS‐Back and the last follow‐up VAS‐Back in men (t = 4.61, P < 0.05) and women (t = 6.57, P < 0.05). In addition, there was significant differences between preoperative VAS‐Leg and the last follow‐up VAS‐Leg in men (t = 13.48, P < 0.05) and women (t = 26.87, P < 0.05). There were significant differences between preoperative ODI scores (44.84 ± 10.82%) and the last follow‐up ODI scores (11.12 ± 5.80%) (t = 10.92, P < 0.05). Preoperative ODI scores and the last follow‐up ODI scores were significantly different for men (t = 8.80, P < 0.05) and women (t = 6.63, P < 0.05). All patients received significant pain relief and functional improvement after the surgery. Except for two cases of postoperative dysesthesia and one dural tear, no severe complications occurred. The dysesthesia symptoms of these two patients disappeared within 1 week with the application of dexamethasone and neurotrophic drugs and the dural tear case also recovered well as the dural laceration was small. No poor results were reported and 89.47% of patients achieved excellent or good recovery.

Conclusion

Percutaneous endoscopic lumbar discectomy via the transforaminal approach combined with the interlaminar approach under epidural anesthesia can treat L4/5 and L5/S1 two‐level disc herniation safely and effectively.

Cadaveric anatomy of the lumbar triangular safe zone of Kambin's in North West Indian population

A three dimensional triangular space ‘the Kambin’s triangle (KT)’ present on the dorsolateral aspect of the intervertebral disc, is considered to be a safe area for transforaminal approaches. It allows access to the exiting and traversing nerve roots, the thecal sac and to the intervertebral disc spaces. Our aim was to calculate the area of the triangle by measuring the height and base at all the intervertebral spaces bilaterally in the lumbar region in North West Indian cadavers and to assess the diameter of circle inscribed within this triangle which will correspond to the size of cannula inserted for the minimally invasive transforaminal approaches in this population. Five randomly chosen adult cadavers were used for this study. After clearing the area, the exiting nerve was identified. The height and base of the bony KTs (n=40) were measured with the help of digital Vernier’s calliper (accuracy 0.02 mm) to calculate the area of the KT. There is a steady increase in the area of the bony KT reaching maximum at the level of L4-5 intervertebral space. Statistically there were no differences in the calculated areas between right and left side. The mean diameter of inscribed circle within the triangle also showed gradual increase from 5.82 mm at L1-2 level, reaching maximum value of 7.26 mm at L4-5 level on the right side while on the left side the values were 5.66 mm and 8.16 mm respectively. Careful anatomical consideration is of utmost importance in transforaminal approaches during surgical or interventional procedures in this region. Cannula having external diameter ranging 6–8 mm is recommended for any interventional approach through Kambin’s space.

Linical efficacy of percutaneous endoscopic lumbar discectomy for the treatment of lumbar spinal stenosis in elderly patients: a retrospective study

Background

Although percutaneous endoscopic lumbar discectomy (PELD) is increasingly being used to treat lumbar degenerative disease, the treatment of elderly patients with lumbar spinal stenosis (LSS) involves considerable uncertainty. The purpose of this study was to evaluate the safety and effectiveness of PELD for the treatment of LSS in elderly patients aged 65 years or older.

Methods

In this retrospective review, 136 patients aged 65 years or older who underwent PELD to treat LSS were evaluated. The patients were divided into two groups, group A (ages 65–74) and group B (age ≥ 75), and perioperative data were analyzed. The Japanese Orthopaedic Association (JOA) score, visual analog scale (VAS) score, and MacNab classification were used to evaluate postoperative clinical efficacy.

Results

All patients successfully underwent the operation with satisfactory treatment outcomes. Compared to preoperative scores, the self-reported scores or pain while performing daily activities were significantly improved in both treatment groups (P < 0.05). No statistically significant between-group differences were observed in operation time, intraoperative blood loss, postoperative bed rest, and postoperative hospital stay (P > 0.05). The overall postoperative complication rate was similar between the two groups. Moreover, no statistically significant differences in VAS-back pain scores, VAS-leg pain scores, JOA scores, and MacNab classification were found between the groups at the 3-month and 1.5-year follow-up examinations (P > 0.05).

Conclusion

PELD is safe and effective for the treatment of LSS in elderly patients. Age is not a contraindication for decompressive lumbar spine surgery. PELD has advantages such as reduced trauma, fewer anesthesia-related complications, and a fast postoperative recovery. Elderly patients should be considered good candidates for lumbar decompression surgery using minimally invasive techniques.

Technical Considerations of the Transforaminal Approach for Lumbar Disk Herniation

Transforaminal full endoscopic lumbar diskectomy (TELD) is a typical minimally invasive surgery, with the associated benefit of decreased possibility of anatomic structural injury, and is an effective alternative to open diskectomy. Among the various endoscopic spinal surgical techniques currently available, TELD is the most basic and traditional surgery that can be performed through the transforaminal route; it has been used for >30 years. Recently, with the advancements in surgical techniques, TELD has been successfully performed for patients with lumbar disk herniation of different types. However, beginner surgeons are unfamiliar with the anatomy of transforaminal endoscopic surgery and this surgery has a steep learning curve to date. If not well prepared, operators may experience complications that require reoperation in the early stages. These complications may include symptomatic incomplete decompression, exiting nerve root injury, dural tearing, and rarely, hematoma, infection, and visceral injury. Here, we propose several technical guidelines for TELD to increase the possibility of successful lumbar diskectomy and to reduce the incidence of complications. The first step is the accurate anatomic understanding of Kambin triangle and determining the appropriate endoscopic access angle, depending on the type of disk herniation. The second step is to determine a safe and easily accessible entry point and then landing and docking the working sleeve as close to the target as possible without causing exiting nerve root injury. The third step is complete decompression of the symptomatic nerve with free mobilization of the neural tissue. The final step involves performing foraminoplasty using an advanced technique to overcome the limitations associated with TELD in difficult cases.

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.

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

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

A Novel Foraminoplasty Technique for Posterolateral Percutaneous Transforaminal Endoscopic Lumbar Surgery

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Transforaminal Endoscopic Approach for Large-Sample Tumor Biopsy using Beveled Working Channel for Core Technique: A Technical Note

BACKGROUND

Identifying the histopathological diagnosis of a spinal tumor is the necessary step prior to pursuing subsequent treatment. Both minimally invasive and open spinal procedures have been described as useful methods of obtaining tumor tissue for diagnosis but differ by their limitations. Minimally invasive techniques, such as computed tomography-guided biopsies, can expose the patient to radiation, and the tissue obtained may be nondiagnostic. Tubular and open procedures require collateral soft-tissue damage and may require bony removal leading to iatrogenic injury. Endoscopic approaches to the spine can be employed to avoid treatment delay in diagnosis, decrease length of stay, and provide adequate tissue for diagnosis.

METHODS

We describe the surgical planning, tumor localization, and transforaminal endoscopic approach for tissue diagnosis of a lumbar spinal mass in a patient with a known history of Hodgkin lymphoma and non-Hodgkin lymphoma after a nondiagnostic computed tomography- guided biopsy. Final histopathological diagnosis of the lumbar spinal mass was consistent with large B-cell non-Hodgkin lymphoma.

CONCLUSIONS

We demonstrate the application of an endoscopic transforaminal approach in spine oncology. We also describe our technique on how we use a beveled working channel to obtain a large tissue core sample for definitive diagnosis.

[Technical notes and clinical efficacy analysis of full-endoscopic thoracic discectomy via transforaminal approach]

Objective: To study the technical notes and clinical efficacy of full-endoscopic thoracic intervertebral discectomy via transforaminal approach. Methods: We included 16 patients with thoracic disc herniation treated by full-endoscopic thoracic discectomy via transforaminal approach between January 2017 and September 2018 in ours department of orthopedics. The average age is 53.7 years. The compressionare classified by nature: 5 cases of soft thoracic disc herniation, 7 cases of calcified or ossified thoracic disc herniation, and 4 cases of osteophyte protrusion of the posterior edge of the adjacent vertebral body of the diseased disc. All patients had symptoms of thoracic myelopathy before operation, and 7 of them had radiculopathy. Via transforaminal approach under local anesthesia, enlarged foraminoplasty and full-endoscopic thoracic discectomy were used for treatment. Observe the changes of postoperative imaging, pain symptoms and recovery of spinal cord function at 1 week, 3 months, 6 months and 1 year after operation. Back pain and radicular pain were scored with VAS, neurological function was assessed with Nurick score and mJOA score, and thoracic spine function was assessed with Oswestry disability index (ODI). Results: All operations were successfully completed, and no intraoperative conversion of surgical methods occurred. Postoperative thoracic MRI and CT examinations of all patients showed that the spinal cord was fully decompressed without any residual compression. Back pain and radicular pain were all relieved obviously in all patients, and spinal cord function was obviously restored. Transient intercostal neuralgia occurred in 2 cases after operation, and no other surgical complications occurred. Conclusions: Full-endoscopic or fluoroscopic foraminoplasty and full-endoscopic thoracic discectomyvia transforaminal approach under local anesthesia is a safe and effective treatment for soft and hard thoracic disc herniation located on the ventral side of the spinal cord.

Fully Endoscopic Transforaminal-Transchoroidal Approach for Tectal Area Tumor Removal

BACKGROUND

The surgical approaches to lesions located in the tectal area have remained controversial. The essential functions in the surrounding areas and the difficulties in obtaining a good surgical view during tumor removal have made these procedures risky and challenging. Endoscopic transforaminal approaches have been previously described for biopsy and intraventricular tumor removal. However, the endoscopic transforaminal-transchoroidal gross resection technique for such cases has barely been described.

METHODS

The endoscopic entry points and trajectories were planned using preoperative magnetic resonance imaging. Once the endoscope was inside the ventricular system, the angles of work and tumor exposure of the upper posterior part of the third ventricle were carefully evaluated. If the angle of work was insufficient for tumor removal, the choroidal fissure was opened using endoscopic bipolar electrode and dissectors. Tumor removal was performed using an endoscopic ultrasonic aspirator. We have presented a 3-case series of patients affected by tectal tumors that were treated using a fully endoscopic transforaminal-transchoroidal approach.

RESULTS

Total gross resection of the tumors was achieved in 2 patients. Subtotal resection was achieved in the third patient. No major complications had developed in relationship to the procedure. No new cognitive impairment was reported secondary to this technique.

CONCLUSIONS

In our experience, a fully endoscopic transforaminal-transchoroidal approach was a suitable treatment for this complex pathological entity. Opening of the choroidal fissure added an extra angle of work and improved the exposure of the upper posterior part of the third ventricle.

Modified technique for thermal radiofrequency ablation of Thoracic dorsal root ganglia under combined fluoroscopy and CT guidance: a randomized clinical trial

Background

This study is comparing thermal radiofrequency ablation (TRFA) of the thoracic dorsal root ganglia (TDRG) guided by Xper CT and fluoroscopy with the standard fluoroscopy.

Methods

This randomized clinical trial included 78 patients suffering from chronic refractory pain due to chest malignancies randomly allocated into one of two groups according to guidance of TRFA of TDRG. In CT guided group (n = 40) TRFA was done under integrated Xper CT-scan and fluoroscopy guidance, while it was done under fluoroscopy guidance only in standard group (n = 38). The primary outcome was pain intensity measured by visual analog scale (VAS) score, functional improvement and consumption of analgesics. The secondary outcome measures were patient global impression of changes (PGIC) and adverse effects.

Results

VAS scores decreased in the two groups compared to baseline values (p < 0.001) and were lower in CT guided group up to 12 weeks. Pregabalin and oxycodone consumption was higher in the standard group at 1, 4 and 12 weeks (p < 0.001). Functional improvement showed near significant difference between the two groups (P = 0.06 at week 1, 0.07 at week 4 respectively) while the difference was statistically significant at week 12 (P = 0.04). PGIC showed near significant difference only at week 1 (P = 0.07) while the per-patient adverse events were lower in CT guided group (p = 0.027).

Conclusions

Integrated modality guidance with Xper CT-scan and fluoroscopy together with suprapedicular inferior transforaminal approach may improve efficacy and safety of TRFA of TDRG for the treatment of intractable chest pain in cancer patients.

Trial registration

The study was retrospectively registered at clinicaltrials.gov on 04/22/2018 (Registration No.: NCT03533413).

Comprehensive treatment algorithm for management of thoracic and lumbar tubercular spondylodiscitis by single-stage posterior transforaminal approach

BACKGROUND

Surgery in tubercular spondylodiscitis involves radical debridement and fusion by combined anterior and posterior or all posterior approaches with a posterolateral window with its associated morbidities. This study evaluates the outcome of a comprehensive treatment algorithm for thoracic and lumbar tubercular spondylodiscitis by a single-stage posterior transforaminal approach.

METHODS

One hundred and twenty-six patients with tubercular spondylodiscitis between T1 and S1 who underwent posterior surgery with/without fusion by transforaminal approach with a minimum follow-up of 2 years were analyzed. Radiological outcome was assessed by documenting healing with magnetic resonance imaging/computed tomography and radiographical fusion, while clinical outcome was assessed by visual analog score (VAS) for pain and Frankel grading for neurological recovery.

RESULTS

Of the 114 patients available for follow-up with a mean age of 53 years, complete radiological healing was observed in all patients (100%) with radiographical fusion in 97.4% and neurology recovered to Frankel E in all 37 patients with deficit. The preoperative VAS score of 9.2 improved significantly to 1.7 postoperatively, and all patients returned to their preoperative occupational activities at the final follow-up.

CONCLUSION

This comprehensive treatment algorithm of single-stage posterior surgery by transforaminal approach in thoracic and lumbar tubercular spondylodiscitis provided good clinical and radiological outcomes. It aids in achieving the same surgical goals, obviating the need for extensive posterior or combined surgical approaches.

Pseudoaneurysm of a segmental lumbar artery following a full-endoscopic transforaminal lumbar discectomy: a rare approach-related complication

Full-endoscopic transforaminal lumbar discectomy is based on a puncture technique using a guide needle to reach the target area of the foramen via a percutaneous posterolateral/lateral approach. It may correlate with specific approach-related complications, as exiting nerve root injury. We report the first case of pseudoaneurysm of the lumbar segmental artery secondary to a transforaminal full-endoscopic surgery in the treatment of a lumbar herniated disc. A 39-year-old man underwent left L4-L5 full-endoscopic transforaminal lumbar discectomy for a herniated disc. Three hours after surgery, he experienced acute progressive abdominal pain. An abdomen CT scan showed contrast extravasation in the left paraspinal compartment at L4 vertebral body level. The selective left lumbar angiogram revealed a pseudoaneurysm of a side branch of the left lumbar segmental artery, which was treated by endovascular coiling. The patient made a rapid postoperative recovery without further complications and was discharged 4 days later. This report identifies a rare complication of transforaminal full-endoscopic surgery in the treatment of a herniated lumbar disc. To our knowledge this is the first case of pseudoaneurysm formation of the lumbar artery following a full-endoscopic transforaminal lumbar discectomy.

Evolution of Spinal Endoscopic Surgery

Innovations in the development of endoscopic spinal surgery were classified into different generations and reviewed. Future developments and directions for endoscopic spinal surgery were discussed. Surgical therapy for spinal disease has been gradually changing from traditional open surgery to minimally invasive spinal surgery. Recently, endoscopic spinal surgery, which initially was limited to the treatment of soft tissue lesions, has expanded to include other aspects of spinal disease and good clinical results have been reported. As the paradigm of spinal surgery shifts from open surgery to endoscopic surgery, we discussed the evolution of endoscopic spine surgery in our literature review. Through this description, we presented possibilities of future developments and directions in endoscopic spine surgery.

Recurrent upper lumbar disc herniation treated via the transforaminal approach using microendoscopy-assisted lumbar discectomy: a case report

BACKGROUND

Although microendoscopy-assisted lumbar discectomy for lateral or extraforaminal lumbar disc herniations via the lateral approach has previously been reported, microendoscopy-assisted lumbar discectomy for central or paramedian disc herniations via the lateral approach has not been reported. We report the first case of recurrent upper lumbar disc herniation (L2-L3) treated with microendoscopy-assisted lumbar discectomy via the transforaminal approach. No microendoscopy-assisted lumbar discectomy for recurrent upper lumbar disc herniation via the transforaminal approach has previously been reported. Percutaneous endoscopic lumbar discectomy via the transforaminal approach is very useful as a minimally invasive surgery for disc herniations. We applied percutaneous endoscopic lumbar discectomy via the transforaminal approach, and invented a new microendoscopy-assisted lumbar discectomy via the transforaminal approach.

CASE PRESENTATION

A 79-year-old Japanese man was operatively managed for recurrent L2-L3 herniation. An 18 mm skin incision was made approximately 70 mm from the midline to the lateral side to allow a sufficiently angled trajectory to the extraforaminal space. The transforaminal approach was used. The exiting nerve root was identified along its course inferior to the pedicle. The lateral portion of the pars interarticularis and the facet joint was removed using a high-speed drill under the guidance of an endoscope. The tip of the endoscope was set at the lateral side of the dura mater. The dura mater was retracted medially and gently, and the herniated disc fragments were removed safely. All symptoms were relieved postoperatively. Postoperative magnetic resonance imaging demonstrated disappearance of all herniated disc fragments. A postoperative three-dimensional computed tomographic scan demonstrated the complete preservation of the facet joint.

CONCLUSIONS

This is the first report of a case of recurrent upper lumbar disc herniation treated with microendoscopy-assisted lumbar discectomy via the transforaminal approach. This procedure allows for the use of a nerve retractor and other instruments to detach adhesions from the dura mater. This procedure has the advantages of clear visualization of the dura mater, exiting nerve root, and traversing nerve root, and diminished risk of nerve injury, and complete preservation of the articular surface of the facet joint.

[Application of broad easy immediate surgery in percutaneous transforaminal endoscopic technology for lumbar lateral recess stenosis in the elderly]

OBJECTIVE

To explore the safety and effectiveness of percutaneous transforaminal endoscopic BEIS technology for lumbar lateral recess stenosis in the elderly.

METHODS

From February 2014 to May 2016, 21 patients with lumbar lateral recess stenosis in elderly were treated with percutaneous endoscopic BEIS. There were 13 males and 8 females, aged from 70 to 85 years old with an average of 74.3 years. Preoperative, 1 and 12 months postoperative visual analogue scale(VAS) scores and Oswestry Disability Index(ODI) were statistically analyzed. MacNab was used to assess the clinical effects.

RESULTS

All the operations were successful. The time ranged from 90 to 130 min with an average of 110 min. All the patients were followed up for 12 to 38 months with an average of 18 months. Preoperative, 1 and 12 months postoperative VAS scores were 8.47±1.23, 1.78±0.72, 0.68±0.32, and ODI scores were 32.48±10.03, 19.53±3.55, and 5.15±1.02, respectively. Postoperative scores of VAS and ODI were obviously improved(P<0.05). According to modified MacNab standard to evaluate the clinical effects, 14 cases obtained excellent results, 5 good, 2 fair. Lower limb paresthesia occurred in 1 case, and the condition was restored at 3 months postoperatively with conservative treatment. One patient was complicated with emphysema before operation secondary to pulmonary infection, and was effectively controlled with regulate antibiotic therapy. No infection of vertebral body or intervertebral space, no injuries of blood vessels or nerve root, no tear of dura, or the leakage of cerebrospinal fluid were found.

CONCLUSIONS

Percutaneous transforaminal endoscopic BEIS is a safe and effective method for lumbar lateral recess stenosis in the elderly.

Anatomical considerations of the iliac crest on percutaneous endoscopic discectomy using a transforaminal approach

BACKGROUND CONTEXT

Percutaneous endoscopic discectomy is a minimally invasive procedure for the surgical treatment of lumbar disc herniation (LDH). It can be performed under local anesthesia and requires a skin incision of only 8 mm, with minimal disruption of the spinal structures including ligaments and muscles. However, performing percutaneous endoscopic discectomy with a transforaminal approach (TF-PED) for the lower lumbar spine is associated with some anatomical problems, such as interference from the iliac crest. This study sought to assess the operability of TF-PED for the lower lumbar spine.

PURPOSE

The purpose of this study was to assess a three-dimensional relationship between the trajectory of TF-PED and the iliac crest, and the operability of TF-PED at the lower lumbar disc levels (L4-L5 and L5-S1) using CT images.

STUDY DESIGN

This is a retrospective study using 323 multiplanar abdominal computed tomography (CT) scans.

PATIENT SAMPLE

We retrospectively reviewed contrast-enhanced multiplanar abdominal CT scans of 323 consecutive patients (203 male and 120 female) in our hospital from April 2009 to March 2013. The mean age was 66.5 (range 15-89) years old.

OUTCOME MEASURES

The operability of the TF-PED was the outcome measure.

MATERIALS AND METHODS

We defined the tangent line in the iliac crest and the superior articular process of the caudal spine as the trajectory line of TF-PED, and evaluated the maximum inclination angle of the trajectory of the TF-PED (α angle) at the L4-L5 and the L5-S1 disc levels. Assuming the use of an oblique viewing endoscope at 25°, we defined α angle≥65° as the operability of TF-PED.

RESULTS

(1) Relationship between iliac crest and disc level: The trajectory of the TF-PED interfered with the iliac crest at L4-L5 in 40.2% (right) and 54.5% (left) of the subjects, and at L5-S1 in 99.7% and 100% of the subjects. (2) The maximum inclination angle of the trajectory of TF-PED: the α angles were 84.3° and 82.3° at the L4-L5, and 56.8° and 55.2° at L5-S1. (3) Laterality of the α angle: At both disc levels, the mean age of the subjects with a laterality of ≥10° was significantly higher than that of subjects with a laterality of <10°. (4) Operability of TF-PED: At L4-L5, TF-PED could be performed in 94.4% and 90.4% of the subjects. In contrast, at L5-S1 the procedure could be performed in 24.1% and 19.2% of the subjects (male: 15.8% and 10.8%, female: 38.3% and 33.3%).

CONCLUSIONS

From the results of this study, the trajectory of TF-PED can be limited by the surrounding anatomical structures. The maximum inclination angle indicated that treatment for the central type of LDH at the L5-S1 disc level was considered more difficult than that at the L4-L5 disc level because of the iliac crest. In the clinical setting, such anatomical particularities can be overcome by using a more perpendicular approach (hand-down technique) with the possible addition of a foraminoplasty. Moreover, we found that we must consider the laterality of the trajectory of TF-PED in terms of the patients' age or sex.

Hidden and overall haemorrhage following minimally invasive and open transforaminal lumbar interbody fusion

BACKGROUND

Hidden haemorrhage has been proved to be significant in joint surgery. However, when referring to lumbar interbody fusion, it is often ignored because of its invisibility. This randomized controlled study aimed to calculate and compare hidden haemorrhage following minimally invasive and open transforaminal lumbar interbody fusion (MIS-TLIF and open TLIF). Meanwhile, its clinical significance was also analyzed.

MATERIALS AND METHODS

A total of 41 patients were included in this study, then they were randomized to receive MIS-TLIF or open TLIF, 21 and 20, respectively. For each case, total volume loss of red blood cell (RBC) was calculated by Gross' formula based on perioperative haematocrit change, then perioperative visible volume loss of RBC was calculated through haemorrhage volume and weight. After deducting it from total volume loss of RBC, hidden volume loss of RBC was obtained. Absolute amount of hidden haemorrhage and its ratio upon total haemorrhage, as well as indicators assessing clinical outcomes, including visual analogue scale (VAS) for back and leg, Oswestry disability index (ODI), interbody fusion rate and complication incidence were compared and analyzed.

RESULTS

Mean hidden volume loss of RBC in MIS-TLIF was significantly reduced compared with open TLIF (166.7 versus 245.6 ml). Besides, both mean total and visible volume loss of RBC in MIS-TLIF were also statistically less than those in open TLIF (355.3 versus 538.6 ml; 188.6 versus 293.0 ml). While mean ratio of hidden haemorrhage upon total haemorrhage was 46.7% for MIS-TLIF and 44.5% for open TLIF, respectively, showing no statistical significance. At one week postoperatively, more significant improvements of VAS for back and leg, as well as ODI were seen in MIS-TLIF compared with open TLIF. While at final follow-up of at least 2 years, all parameters continued to improve and revealed no statistical difference between both surgeries. Similar interbody fusion rate and complication incidence were observed in both series.

CONCLUSIONS

Besides reduced visible haemorrhage and improved clinical outcomes, MIS-TLIF also owns the superiority of less hidden haemorrhage, offering another advantage over open TLIF.

LEVEL OF EVIDENCE

Level II.

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.

Transforaminal Resection of Cervical Dumbbell Schwannomas in Patients with Additional Tumors

BACKGROUND

It is rare for 2 primary tumors to occur simultaneously in a patient. Management of cervical dumbbell schwannomas (CDSs) with concurrent tumors (CTs) requires a specific neurosurgical strategy. The primary objective of this study is to investigate surgical strategies for CDSs with CTs while preserving as much of the mechanically relevant bone structures as possible.

METHODS

Twelve patients with concurrent CTs and CDSs were identified from 3 medical centers. Surgical strategies for CDSs were based on accurate preoperative images and subsequent treatment considerations for CTs. All patients received surgical treatment for CDSs and CTs. Clinical features, surgical considerations for a transforaminal approach (TA), and ultimate outcome were studied retrospectively.

RESULTS

Gross total resection of CDSs was achieved with endoscopic and microscopic assistance in 9 cases, and subtotal resection was achieved in 3 cases after the head and neck surgeons exposed and removed the extraforaminal anatomy. One patient required an additional hemilaminectomy for the resection of the intraspinal segment. After wound healing, patients were transferred to the appropriate surgical department for surgery on CTs with cervical spine stabilization after a transforaminal approach.

CONCLUSIONS

In most patients, the stability of the cervical spine can be preserved with low invasive microsurgical or endoscopic transforaminal resection. CTs could be surgically treated sequentially after microscopic- and endoscopic-assisted resection of CDSs.

Intraforaminal ozone therapy and particular side effects: preliminary results and early warning

BACKGROUND

The term "low back pain syndrome" represents a complex nosological entity. The therapeutic approach is often only symptomatic and not etiologic.

METHODS

Since 2013, 186 patients (97 males and 89 females, mean age 59.8 years) have undergone microsurgery for lumbar disc hernia or lumbar segmental stenosis. Among these patients, 23 had been previously treated with ozone therapy by the intraforaminal approach and 28 by intraforaminal steroid injections in other hospitals between 12 and 24 months before our clinical evaluation. These patients received 16 applications in an 8-week period (standard therapy).

RESULTS

During the surgery, many hard adhesions between the soft tissues and bony structures were unexpectedly discovered. In particular, it was noted that the root contracted and had firm adhesions to the dural sac and/or fragmented disc, which were difficult to resolve. These specific pathological patterns were observed only in the patients who received ozone injections by the intraforaminal approach. We did not find any pathological abnormalities in the patients who did not receive any injections or who received intraforaminal steroid injections. Thus, we could exclude that the tissue damage was due to the mechanical action of the needle.

CONCLUSION

It is important to assert that ozone therapy procedures can be associated with several major complications. Therefore, performing a revision of the guidelines and protocols for ozone therapy application is indispensable.