Full-endoscopic interlaminar and transforaminal lumbar discectomy versus conventional microsurgical technique: a prospective, randomized, controlled study

AOSpine Consensus Paper on Nomenclature for Working-Channel Endoscopic Spinal Procedures

STUDY DESIGN

International consensus paper on a unified nomenclature for full-endoscopic spine surgery.

OBJECTIVES

Minimally invasive endoscopic spinal procedures have undergone rapid development during the past decade. Evolution of working-channel endoscopes and surgical instruments as well as innovation in surgical techniques have expanded the types of spinal pathology that can be addressed. However, there is in the literature a heterogeneous nomenclature defining approach corridors and procedures, and this lack of common language has hampered communication between endoscopic spine surgeons, patients, hospitals, and insurance providers.

METHODS

The current report summarizes the nomenclature reported for working-channel endoscopic procedures that address cervical, thoracic, and lumbar spinal pathology.

RESULTS

We propose a uniform system that defines the working-channel endoscope (full-endoscopic), approach corridor (anterior, posterior, interlaminar, transforaminal), spinal segment (cervical, thoracic, lumbar), and procedure performed (eg, discectomy, foraminotomy). We suggest the following nomenclature for the most common full-endoscopic procedures: posterior endoscopic cervical foraminotomy (PECF), transforaminal endoscopic thoracic discectomy (TETD), transforaminal endoscopic lumbar discectomy (TELD), transforaminal lumbar foraminotomy (TELF), interlaminar endoscopic lumbar discectomy (IELD), interlaminar endoscopic lateral recess decompression (IE-LRD), and lumbar endoscopic unilateral laminotomy for bilateral decompression (LE-ULBD).

CONCLUSIONS

We believe that it is critical to delineate a consensus nomenclature to facilitate uniformity of working-channel endoscopic procedures within academic scholarship. This will hopefully facilitate development, standardization of procedures, teaching, and widespread acceptance of full-endoscopic spinal procedures.

Risk Factors for Recurrent L5-S1 Disc Herniation After Percutaneous Endoscopic Transforaminal Discectomy: A Retrospective Study

Background

This retrospective study aimed to investigate the risk factors associated with the recurrence of L5–S1 disc herniation after percutaneous endoscopic transforaminal discectomy (PETD).

Material/Methods

There were 484 patients L5–S1 disc herniation who underwent PETD who were divided into the recurrence group (n=46) and the non-recurrence group (n=438). Transforaminal endoscopic approaches included modifications of the Yeung endoscopy spine system (YESS) (the intraforaminal intradiscal approach) and the transforaminal endoscopic spine system (TESSYS) (intraforaminal extradiscal approach). Demographic and clinical characteristics and imaging data were analyzed. The two study groups were compared to determine the factors associated with the recurrence of L5–S1 disc herniation. The patients underwent postoperative follow-up for between one and four years.

Results

At follow-up, 9.504% of patients (46/484) with the recurrence of L5–S1 disc herniation following PETD when compared with the non-recurrence group showed no significant difference for time to return to work, gender, history of diabetes mellitus, trauma, duration of symptoms, smoking and alcohol history, hypertension, location of disc herniation, transverse process length, intervertebral space height, and pelvic incidence angle (P>0.05). However, age, body mass index (BMI), the degree of disc degeneration, sagittal range of motion, lumbar lordosis angle, and sacral slope were significantly associated with the recurrence of L5–S1 disc herniation following PETD (P<0.05). Logistic regression analysis supported these main associations.

Conclusions

The recurrence of L5–S1 disc herniation following PETD was significantly associated with increased age and BMI, more severe disc degeneration, increased sagittal range of motion, increased lumbar lordosis, and sacral slope.

The Value of a Synthetic Model-based Training Lab to Increase Proficiency with Endoscopic Approaches to the Spine

Introduction: The learning curve associated with endoscopic approaches to the spine is well established. In this study, we present our endoscopic training methodology and discuss the concepts and rationale of laboratory training as it relates to improving comfort and skill with endoscopic techniques.

Materials and Methods: A three-part endoscopic training laboratory for neurosurgical trainees and attendings was organized at the University of Miami, which included a lecture, instrumentation demonstration, and both synthetic model and cadaveric practice sessions. Participants completed pre- and post-lab surveys gauging their comfort and competency in the transforaminal approach to the lumbar spine.

Results: There were a total of 22 participants, with eight completing the pre-lab survey and 10 completing the post-lab survey. Sixteen participants engaged in the lab practical, with six of these participants performing the transforaminal approach on both the model and the cadaver. An increase in comfort level was demonstrated on the post-lab survey (5.9/10) for the transforaminal approach as compared to the pre-lab survey (2.6/10). Additionally, participants found the training model to be an effective teaching aid for the transforaminal technique (8.8/10).

Conclusions: We believe that our study demonstrates the utility of simulated model-based training for gaining comfort and proficiency with endoscopic approaches to the spine and introduces a safe, cost-effective method of educating practitioners on novel endoscopic approaches.

Comprehensive Anatomic and Morphometric Analyses of Triangular Working Zone for Transforaminal Endoscopic Approach in Lumbar Spine: A Fresh Cadaveric Study

OBJECTIVE

The aim of this study is to provide essential information for endoscopic transforaminal approach by performing morphometric analysis of the triangular working zone (TWZ) in fresh cadavers.

METHODS

Fifteen fresh human cadavers (9 women and 6 men) with no history of spinal surgery were used in this study. Anatomic dissection of 150 foraminal levels were performed. Significant surgical landmarks constructing TWZ were measured bilaterally from L1-2 to L5-S1 on 15 fresh cadavers. The relationship between traversing roots and intervertebral discs was defined.

RESULTS

Base, height, and hypotenuse measurements of TWZ were longer as the level lowered. Mean base height and hypotenuse of TWZ were 12.15 mm, 11.29 mm, and 16.69 mm (L1-2); 17.94 mm, 17.18 mm, and 28.03 mm (L5-S1), respectively. TWZ was triangular shaped at the upper lumbar levels (L1-2, L2-3, and L3-4), and trapezoid at the lower lumbar levels (L4-5 and L5-S1). Going down the levels, the exiting root angle was narrower, the mean exiting angle of the L5 root being 28.23°. All L2 and L3 traversing roots and nearly all L4 traversing roots (86.7%) originated from below the disc level. Forty percent of L5 traversing roots originated above the disc level, and 53.3% originated at the disc level. Most S1 traversing roots originated at the proximal margin of the disc level (80%).

CONCLUSIONS

Our study reveals a detailed morphometric analysis of TWZ. Understanding the foraminal anatomy is crucial for safely performing transforaminal endoscopic surgery. The learning curve of transforaminal surgery can be reduced by garnering knowledge of TWZ anatomy.

Fibrin sealants in lumbar annuloplasty after endoscopic discectomy as a method to prevent recurrent lumbar disc herniation

Fibrin sealant as a promising agent for providing scaffold and efficient hemostasis is widely accepted in several specialties. However, the outcome of Fibrin sealants in lumbar annuloplasty after endoscopic discectomy has not been evaluated in patients with disc herniation. The goal of this study was to evaluate the efficacy, response, and probability of future recurrence rates in herniated nucleus pulposus (HNP) with the use of fibrin sealant in conjunction with endoscopic disc surgery. A total of 35 patients (28 men, 7women) were evaluated, including 18 patients who underwent endoscopic discectomy alone and 17 patients that received fibrin sealant at the site of annulus tear and endoscopic discectomy. All patients were followed through both clinical and imaging methods for an average of 10.5 months. Primary outcome measure was defined as lumbar decompression approved by imaging and symptom alleviation after endoscopic spinal discectomy with Visual Analogue Scale (VAS) score ≤ 4 (cut-off point). Median size of annular tearing was significantly lower in the endoscopic discectomy group (median, 3) (minimum, 2; maximum, 5); however, the corresponding factor in the endoscopic discectomy plus fibrin sealant group was significantly larger (median, 6) (minimum, 5; maximum, 10), with P <0.001. Only one patient in the endoscopic discectomy group had an HNP recurrence during follow-up compared to two patients in the endoscopic discectomy plus fibrin sealant group. Due to the temporary effects of fibrin sealant in preventing disc herniation and the observed recurrence rate in both the case and control groups, the results of this study suggest a role of fibrin sealants combined with endoscopic discectomy to prevent early HNP recurrence rate.

Learning Curve and Early Results of Interlaminar and Transforaminal Full-Endoscopic Resection of Lumbar Disc Herniations

Background

Full-endoscopic spinal surgery is an evolving technique. A laborious learning phase is inevitable due to the complexity of the orientation and instrumentation. The goal of the present study is to evaluate a single surgeon’s learning curve and early outcomes in full-endoscopic resection of lumbar disc herniations.

Methods

This was a prospective non-controlled single-surgeon cohort study. In 54 patients with 57 herniations, 41 interlaminar and 16 transforaminal resections were performed. Surgery time, severity of adhesive process in the spinal canal, complication rates and clinical outcomes (VAS, ODI, custom questionnaire, recurrence and re-operation rate) were assessed.

Results

In the interlaminar group, operative time has decreased from 60 ± 20 min in the first 20 operations to 45 ± 14 min in the following 17 (p=0.023). In the transforaminal group, operative time has decreased from 60 ± 16 min in the first 7 operations to 41 ± 12 min in following 9 (p=0.023). Severe adhesive process in spinal canal was associated with duration of symptoms greater than 2 years, longer surgery and higher risk of surgical complications. Four recurrent disc herniations were re-operated using full-endoscopic technique. VAS, ODI and pain medications significantly decreased in both groups and in re-operated patients.

Conclusion

The plateau of the learning curve and good short-term clinical results of full-endoscopic interlaminar and transforaminal surgery may be achieved after twenty operations, given extensive previous experience in microsurgery. Risk of complications at the learning phase may be decreased by excluding the patients with symptoms lasting over two years.

International Society for the Advancement of Spine Surgery Policy 2019-Surgical Treatment of Lumbar Disc Herniation with Radiculopathy

Lumbar disc herniation (LDH) is a frequent cause of low back pain and radiculopathy, disability, and diminution in quality of life. While nonsurgical care remains the mainstay of initial treatment, symptoms that persist for prolonged periods of time are well treated with discectomy surgery. A large body of evidence shows that, in patients with unremitting symptoms despite a reasonable period of nonsurgical treatment, discectomy surgery is safe and efficacious. In patients with symptoms lasting greater than 6 weeks, various forms of discectomy (open, microtubular, and endoscopic) are superior to continued nonsurgical treatment. The small but significant proportion of patients with recurrent disc herniation experience less improvement overall than patients who do not experience reherniation after primary discectomy. Lumbar discectomy patients with large annular defects (≥6 mm wide) are at a higher risk for recurrent herniation and revision surgery. Annular closure via a bone-anchored device has been shown to decrease the rate of recurrent disc herniation and associated reoperation in these high-risk patients. After a detailed review of the literature, current clinical evidence supports discectomy (open, microtubular, or endoscopic discectomy) as a medically necessary procedure for the treatment of LDH with radiculopathy in indicated patients. Furthermore, there is new scientific evidence that supports the use of bone-anchored annular closure in patients with large annular defects, who are at greater risk for recurrent disc herniation.

Percutaneous Endoscopic Lumbar Discectomy Versus Microdiscectomy for the Treatment of Lumbar Disc Herniation: Pain, Disability, and Complication Rate-A Randomized Clinical Trial

Purpose

The objective was to compare the traditional microdiscectomy with percutaneous endoscopic lumbar discectomy for the treatment of disc herniations regarding pain, disability, and complications.

Methods

Randomized clinical trial with 47 patients with disc herniations treated with 2 different surgical techniques: traditional microdiscectomy or percutaneous endoscopic lumbar discectomy. Forty-seven patients were divided into 2 groups and monitored for 12 months. Irradiated and low back pain were evaluated with the visual analog scale. Surgery complications were recorded.

Results

After surgery, the sciatica and disability improved significantly but without significant differences between the groups. Improvements in back pain were significant until the third month. There were no statistical differences between groups regarding recurrence, infection, and the need for reoperation.

Conclusions

Endoscopic discectomy results are similar to those of conventional microdiscectomy regarding pain and disability improvement. Postoperative lumbar pain is less intense with endoscopic discectomy than conventional microdiscectomy only during the first 3 months. Endoscopic discectomy is a safe and efficient alternative to microdiscectomy.

Clinical Trials

Trial protocol registration number: RBR-5symrd (http://www.ensaiosclinicos.gov.br).

Transforaminal Endoscopic Lumbar Discectomy: Clinical Outcomes and Complications

Objective  To evaluate the clinical and functional results of transforaminal endoscopic lumbar discectomy. Materials and Methods  From August 2015 to January 2017, 101 patients with lumbar disc hernia refractory to clinical treatment underwent endoscopic discectomy. Through clinical evaluation by the Visual Analogue Scale and functional evaluation by the Oswestry Disability Index questionnaire, the patients were analyzed in the preoperative period, the immediate postoperative period, at 1 month, 3 months, 6 months and 1 year after surgery. Results  The mean age of the participants was 48.1 years. The most affected disc levels were L4-L5 and L5-S1. A total of 29 patients were treated at 2 disc levels. After 1 month of postoperative follow-up, the mean scores on the questionnaires (VAS and ODI) decreased significantly ( p  < 0.001). Conclusion  Transforaminal endoscopic Lumbar discectomy has been shown to be a safe, effective and minimally-invasive alternative for the treatment of lumbar disc herniation. The procedure has advantages, such as short hospital stay, surgery performed under local anesthesia and sedation, early return to daily activities, and low rate of complications.

Orthobiologic Supplementation Improves Clinical Outcomes Following Lumbar Decompression Surgery

Background

Endoscopic-assisted lumbar decompression is a minimally invasive spine surgery which has been touted to reduce collateral tissue damage, incisional pain, recovery time and complications. Residual back or leg pain and recurrent herniation are commonly reported post-operative outcomes. It has been suggested that injecting orthobiologics like cryopreserved amniotic-derived products (ADPs) and bone marrow aspiration (BMA) into the surgery site would have additional benefit on patient outcomes. This is a Western Institutional Review Board (WIRB)-approved level 1, randomized controlled trial of prospectively collected patient demographic and outcomes data for endoscopic-assisted lumbar decompression surgery. The primary goal of this study was to compare patient outcomes of orthobiologic supplementation during endoscopic-assisted lumbar decompression surgery.

Methods

Following WIRB approval, 269 patients underwent lumbar endoscopic-assisted decompressive surgery between January 2011 and October 2017. Patients were randomized to receive ADP, BMA, both, or no supplementation (control group). Outcomes were measured by post-operative questionnaires (visual analog scale (VAS), Oswestry disability index (ODI), 36-item short-form health survey (SF-36)) over 12 months.

Results

Mean VAS-leg for either BMA or ADP group displayed statistically significant improvements at 2 weeks (3.55 vs. 4.77, P = 0.002), 6 months (2.34 vs. 3.37, P = 0.026), and 9 months (2.18 vs. 3.57, P = 0.01) compared to no supplementation group (control group). Similarly, improvements in mean VAS-back were significant at 2 weeks (3.98 vs. 5.01, P = 0.011), 2 months (3.22 vs. 3.93, P = 0.04), 9 months (2.38 vs. 4.11, P = 0.004), and 12 months (2.23 vs. 3.58, P = 0.011) compared to no supplementation group (control group). There were statistically significant differences in the ODI (2 weeks, 42.19 vs. 31.11, P = 0.014) and SF-36 (4 months, 85 vs. 63, P = 0.043 for ADP only), but these differences did not subsist over time. Two patients (one control, one ADP) re-herniated at the same level.

Conclusions

Orthobiologic BMA and ADP resulted in improved pain control during early post-operative periods.

Transforaminal Endoscopic Lumbar Discectomy and Foraminotomy with Modified Radiofrequency Nerve Stimulator and Continuous Electromyography Under General Anesthesia

BACKGROUND

Transforaminal endoscopic lumbar approaches involve working in Kambin's triangle. These procedures are performed on awake patients or under general anesthesia with continuous electromyography. Potential morbidity of this approach includes injury to exiting and traversing nerve roots, as substantial dissection or cauterization of overlying tissues is required for visualization.

METHODS

We developed a novel connection system that accepts input from a bipolar radiofrequency probe to allow direct nerve stimulation in conjunction with electromyography. This study included 30 consecutive patients undergoing transforaminal endoscopic lumbar approaches for discectomies (73.3%), foraminal stenosis (23.3%), or lateral recess stenosis (3.3%). Demographic, operative, and outcomes data were collected.

RESULTS

Average age of patients was 61.4 years, and the L4-5 segment was most commonly treated (65.6%). Electrophysiologic mapping of the exiting nerve root was attempted in 28 patients with an average stimulation threshold of 8.6 ± 0.9 mA. Mapping of the traversing nerve root was attempted in 12 patients with an average stimulation threshold of 6.0 ± 0.8 mA. There were no instances of new postoperative sensorimotor deficits or dysesthesia. These findings persisted through mean and median follow-up of 294 days and 165 days, respectively. No patient required subsequent lumbar surgery.

CONCLUSIONS

Our modified instrumentation and technique allow for accurate identification of the exiting and traversing nerve roots with minimal changes to the workflow of transforaminal endoscopic lumbar approaches. Modification of a bipolar radiofrequency device connection arrangement is simple, inexpensive, and reusable. In this study, no patients developed injury or pain related to nerve root dysfunction.

Indications Selection for Surgeons Training in the Translaminar Percutaneous Endoscopic Discectomy Based on Finite Element Analysis

Background

Translaminar percutaneous endoscopic discectomy (PED) was used widely in the treatment of lumbar disc herniation (LDH), especially for the training of novice surgeons. A larger range of osteotomy was a suitable method to get enough operation space and reduce intraoperative risks. But osteotomy, especially facetectomy, may be associated with the biomechanical deterioration and resulting adjacent segment diseases (ASD). Hence, the objects of this study were to investigate whether different levels of surgical experience in performing different ranges of osteotomy (especially facetectomy) affected the risk for ASD and to identify the safe indications for the training of PED novice surgeons. Study Design. In this study, a three-dimensional lumbosacral model was constructed and validated. Corresponding translaminar PED models with different ranges of osteotomy for armpit, periradicular, and shoulder types of LDH were constructed. The von Mises stress on the endplates, the shear stress on the annulus, the intradiscal pressure, and the range of motion (ROM) in the L3-L4 segment disc were computed.

Results

Computational results in our well-validated model indicated that large ranges of osteotomy led to deterioration in most of the biomechanical indicators, and this trend was most significant in the shoulder-type LDH model.

Conclusions

To ensure the appropriateness of the surgical prognosis, armpit and periradicular types of LDH can be seen as suitable indications for the training of novice PED surgeons, and shoulder-type LDH should be excluded from such indications until novices can perform PED within a relatively small range of osteotomy. Mini Abstract. Based on biomechanical variations in our finite element analysis, armpit and periradicular types of LDH can be seen as suitable indications for the training of novice PED surgeons, and shoulder-type LDH should be excluded until novices can perform PED within a relatively small range of osteotomy.

Full Percutaneous Transforaminal Lumbar Interbody Fusion Using the Facet-sparing, Trans-Kambin Approach

STUDY DESIGN

This was a prospective, multicenter, consecutive case series' study.

OBJECTIVE

The objective of this study was to evaluate a novel facet-sparing, percutaneous transforaminal lumbar interbody fusion (pTLIF) technique consisting of percutaneous insertion of an expandable interbody cage through an endoscopic cannula with the trans-Kambin approach and complemented with percutaneous transpedicular screws and rods.

SUMMARY OF BACKGROUND DATA

Lumbar interbody fusion by open or minimally invasive surgery is the usual treatment for degenerative disk disease but requires a relatively long recovery period. The transforaminal trans-Kambin approach is a standard in endoscopic spine surgery for safe intradiscal access without facet resection.

METHODS

Preoperative and postoperative Visual Analogue Scale (VAS) and Oswestry Disability Index scores were quantitatively assessed at 1, 3, 6, and 12 months after surgery and then every 12 months for patients treated with pTLIF between 2009 and 2018 in 2 health care centers. An immediate postoperative control computed tomography scan was performed, whereas conventional postoperative x-ray controls were performed at 1 month and 1 year. Statistical evaluation was performed with the Student t test.

RESULTS

A total of 51 patients (mean age, 59.3 y) were evaluated. The overall mean VAS score for axial lumbar pain improved from 6.6 to 1.8 (P<0.01), mean VAS score for leg pain from 5.5 to 1.2 (P<0.01), and mean Oswestry Disability Index scores from 30.3 to 11.8 (P<0.01) postoperatively with a mean follow-up of 27.9 months (range, 1-77.8 mo). Median estimated blood loss was 103.6 mL. Postoperative complications included 12 (22%) cases with transitory ipsilateral dysesthesia, 2 (4%) cases with transitory ipsilateral muscle weakness, and 3 (6%) clinically asymptomatic cases with radiologic cage subsidence. Median hospital stay was 1.4 days (range, 1-3.2 d).

CONCLUSIONS

Postoperative scores for pTLIF significantly improved with minimal blood loss and no long-term complications. On the basis of this experience, the facet-sparing pTLIF is a reliable and safe technique with early hospital discharge, opening the way to outpatient instrumented spine surgery.

LEVEL OF EVIDENCE

Level III.

Longitudinal clinical outcomes after full-endoscopic lumbar discectomy for recurrent disc herniation after open discectomy

OBJECTIVE

Full-endoscopic lumbar discectomy (FELD) is a minimally invasive surgical option for recurrent lumbar disc herniation (LDH). Nonetheless, patients' clinical outcomes may be poorer after surgery for recurrent LDH than for primary LDH. Therefore, we compared patients' longitudinal clinical outcomes after FELD for recurrent LDH or primary LDH.

METHODS

The medical records of patients who underwent FELD for primary LDH (group A) or recurrent LDH (group B) were retrospectively reviewed. The inclusion criteria were: 1) single-level LDH or recurrent LDH at L4-5 or L5-S1, 2) age ≤60 years, 3) previous open discectomy (group B), and 4) ≥6 months of follow-up. In total, 244 patients (group A, 211; group B, 33) were included. Clinical outcomes (Oswestry Disability Index [ODI]; visual analogue pain score for the back and leg [VAS-B] and [VAS-L]) over 24 months of follow-up were compared between groups with a linear mixed-effects model.

RESULTS

All clinical outcomes significantly improved from pre-operation to 3 months postoperatively (p < 0.01), and the improvement was maintained for 24 months postoperatively in both groups. The clinical outcomes of groups A and B were not significantly different during 24 months follow-up (ODI, p = 0.94; VAS-B, p = 0.11; and VAS-L, p = 0.48). The reoperation rate was 3.3% in group A and 3.0% in group B, but the overall complication rate was higher in group B (9.8%) than in group A (6.6%).

CONCLUSION

The longitudinal clinical outcomes after FELD for recurrent LDH may not be poor as feared. However, the higher complication rate in patients undergoing FELD for recurrent LDH should be noted.

Navigating the learning curve of spinal endoscopy as an established traditionally trained spine surgeon

Background

Traditionally trained spine surgeons may want to transition from open spinal surgeries to endoscopic decompressions. The aspiring endoscopic spine surgeon may have to overcome multiple hurdles to master a learning curve without readily available training. Replacing traditional time-proven open spinal surgeries with endoscopic decompression may put the surgeons' reputation at risk and have an additional negative impact on his or her practice due to reduced revenue. The authors report on the utility of the mentor- and proctorship concepts to facilitate the transition from traditional open to endoscopic outpatient spine surgeries.

Methods

The study population (learning curve groups) was provided by two traditionally trained "apprentice" surgeons who have been in practice for 12 and 28 years, respectively. They trained with the remaining two authors under mentorship and proctorship arrangements. A VAS and Macnab outcomes analysis was performed by one surgeon laminectomy versus endoscopy in relationship to the case log representative of the initial learning curve. The second surgeon performed a postoperative narcotic utilization analysis as a representative way of favorable clinical outcomes in relation to his increasing case log with spinal endoscopy.

Results

The learning curve study by the first author (NA Ransom-under the proctorship program) consisted of 40 patients with 20 patients each divided into the traditional laminectomy control group and 20 patients in the endoscopic group. There were 22 females and 18 males with an average age of 57.38 years and a mean follow-up of 38.58 months. The preoperative VAS for patients in both groups was 7.95 compared to the postoperative VAS at final follow-up of 4.01 with a statistically significant postoperative VAS reduction (P<0.001) but without any significant difference between open laminectomy control- and endoscopic decompression groups. The endoscopic learning curve group outcomes improved significantly after 15 cases (P<0.048). The second author (S Gollogly-under mentorship program) performed a similar review of his surgical cases log and noted a significant reduction of postoperative narcotic utilization as a result of improved outcomes after an initial learning curve of 15 cases. Clinical outcomes for both authors showed improved Macnab outcomes in the majority of patients (NA Ransom =65%; S Gollogly =57%) with a slightly higher success rate in the laminectomy group (70%) versus the endoscopy group (65%) at a statistical significant level (P=0.036).

Conclusions

The mentorship and proctorship approach is useful in helping traditionally trained spine surgeons to integrate spinal endoscopy into their well-established spine practices. Under the close guidance of an endoscopic master spine surgeon, the endoscopic learning curve may be comprehended by the experienced traditionally trained spine surgeon in approximately 15 lumbar decompression cases. During this initial 15-case learning curve, clinical outcomes with endoscopy may be slightly inferior to open laminectomy but may ultimately improve to equivalent levels.

Early return to activity after minimally invasive full endoscopic decompression surgery in medical doctors

Full endoscopic surgery including discectomy (FED) and ventral facetectomy (FEVF) is a minimally invasive lumbar decompression surgery that only requires an 8 mm skin incision and can be done under the local anesthesia and sedation. Six male medical doctors underwent the endoscopic decompression (FED/FEVF) for common degenerative lumbar spine problems. Their age ranged from 27 to 63 years of age with a mean of 40 years. Five doctors underwent FED surgery for herniated nucleus pulposus (HNP), and the remaining one physician had FEVF for lumbar lateral recess stenosis. There were no surgery related complications. Postoperatively, 5 out of the 6 physician patients returned the original job within a week because they had clinical duties. The shortest duration to return to work was reported by a 63-year-old orthopedic surgeon resumed working in his clinic 2 days after the FEVF surgery. The longest duration to return to work occurred in general medicine resident who took almost 2 weeks for the sick leave because he did not have clinical duties. The mean duration for the returning to work was 5.8 days after the surgery. At final follow-up ranging from 6 to 30 months, all physician patients were working without any residual pain. In the hands of the authors, the full endoscopic transforaminal decompression surgery is the preferred surgical option and allowed early return to work-an observation that is not the norm in Japan.

Patient selection protocols for endoscopic transforaminal, interlaminar, and translaminar decompression of lumbar spinal stenosis

Background

The indications of different endoscopic and endoscopically assisted translaminar approaches for lumbar spinal stenosis are not well-defined, and validated protocols for the use of the transforaminal over the interlaminar approach are lacking.

Methods

We performed a retrospective study employing an image-based patient stratification protocol of stenosis location (type I-central canal, type II-lateral recess, type III-foraminal, type IV-extraforaminal) and clinical outcomes on 249 patients consisting of 137 (55%) men and 112 (45%) women with an average age of 56.03±16.8 years who underwent endoscopic surgery for symptomatic spinal stenosis from January 2013 to February 2019. The average follow-up of 38.27±27.9 months. The primary clinical outcome measures were the Oswestry Disability Index (ODI), Visual Analogue Scale (VAS), and modified Macnab criteria.

Results

The frequency of stenosis configuration in decreasing order was as follows: type I-121/249; 48.6%, type III-104/249; 41.8%, type II-15/249; 6%, and type IV-9/249; 3.6%. The transforaminal approach (137/249; 55.0%) was used in most type II to IV lesions followed by the interlaminar approach (78/249; 31.3%), and the full endoscopic approach (12/249; 4.8%), and the endoscopically assisted translaminar approach (8/249; 3.2%) which was exclusively used for type I lesions. Macnab outcomes analysis showed Excellent in 47 patients (18.9%), Good in 178 (71.5%), Fair in 18 (7.2%) and Poor in 6 (2.4%), respectively. Paired two-tailed t-test showed statistically significant VAS (5.46±2.1; P<0.0001) and ODI (37.1±16.9; P<0.0001) reductions as a result of the endoscopic decompression surgery. Cross-tabulation of the Macnab outcomes versus the endoscopic approach and surgical technique confirmed beneficial association of the approach selection with Excellent (P=0.001) and Good (P<0.0001) outcomes with statistically significance.

Conclusions

This study suggests that in the hands of skilled endoscopic spines surgeon use of an image-based stenosis location protocol may contribute to obtaining Excellent and Good clinical outcomes in a high percentage (93%) of patients suffering from lumbar stenosis related radiculopathy. Additional comparative studies should examine the prognostic value of choosing the endoscopic approach on the basis of the proposed four-type stenosis protocol by correlating its impact on outcomes with preoperative diagnostic injections and intraoperative direct visualization of symptomatic pain generators under local anesthesia and sedation.

Return to play in professional baseball players following transforaminal endoscopic decompressive spine surgery under local anesthesia

Transforaminal endoscopic discectomy has been established as the least minimally invasive spine surgical procedure because it avoids the surgical morbidity from surgical dissection and denervation of normal anatomy responsible for the functional stability of the spine. There have been few reports on endoscopic spine surgery for professional athletes who are dependent on the preservation of vital anatomy to maintain the highest level of function. This report is on five Japanese professional baseball players who underwent transforaminal endoscopic foraminoplasty-discectomy with pulsed radiofrequency thermal annuloplasty under the local anesthesia. There were no adverse surgical events nor complications. Three athletes suffered from discogenic back pain, one from symptomatic herniated nucleus pulposus (HNP), and another player from sciatica due to foraminal stenosis. Three players decided to undergo surgery at the beginning of the off-season. Therefore, they returned to professional play at the beginning of the following season. The remaining two players underwent surgery just before the beginning of the next season. They all returned to play sooner than with traditional open decompression. Two players returned to play about one month after the start of the season. All five players quickly returned to their sport within three months despite the rigors required of their sport to maintain high proficiency and were able to complete the season.

[Minimally invasive spinal surgery: stages of development]

In recent decades, spinal surgery has changed significantly. The active use of modern knowledge of anatomy, various diagnostic modules, specialized surgical equipment and high-tech tools has made it possible to transform classical surgical techniques into a new area of spinal neurosurgery - minimally invasive spine surgery (MISS). Its main goals are to reduce damage to the skin and adjacent tissues, significantly reduce the level of pain, reduce the duration of inpatient treatment and fully restore functional status in the shortest possible time. This article reflects the main criteria for MISS compliance and types of surgical interventions, provides information on the advantages of minimally invasive surgical technologies and their possible disadvantages. Currently, the use of MISS is observed in all areas of vertebrology - for degenerative diseases, tumors, inflammatory and traumatic lesions of the spine. At the same time, minimizing surgical aggression while maximizing the achievement of goal becomes the main rule of modern spinal surgery.

EVALUATION OF THE LUMBAR SAFETY TRIANGLE THROUGH MAGNETIC RESONANCE IMAGING

ABSTRACT Objective: To evaluate the lumbar triangular safety zone, its boundaries and its relationship with the dorsal root ganglion through Magnetic Resonance Imaging (MRI). Methods: The boundaries, shape and dimensions of 303 triangular safety zones were analyzed in Tesla 3.0 Magnetic Resonance Imaging (MRI) coronal sections from L2 to L5, including the dorsal root ganglion. Results: The sample consisted of 101 patients with a mean age of 32 years. The height of the triangular safety zone was formed by the lateral edge of the dura mater, the width by the upper plateau of the lower vertebra and the hypotenuse by the corresponding nerve root. The mean dimensions and the area varied according to the level studied. The dorsal root ganglion invaded the dimensions of the triangle in all the images studied. Conclusion: Based on the data and the analyses performed, we concluded that knowledge of the boundaries of the triangular safety zone through MRI increases the safety of minimally invasive procedures in the lumbar spine. Level of evidence I; Diagnostic studies – Investigation of a diagnostic test.

Percutaneous endoscopic lumbar discectomy for lumbar disc herniation as day surgery - short-term clinical results of 235 consecutive cases

Many studies have reported the good outcomes of percutaneous endoscopic lumbar discectomy (PELD) for the treatment of lumbar disc herniation (LDH). However, the majority of published studies on PELD showed an average hospital stay of 2 to 5 days. Thus, the purpose of this retrospective study was to evaluate and compare the clinical outcomes of patients undergoing PELD for LDH as day surgery with the outcomes of patients managed as inpatients.A total of 402 patients who underwent PELD for single-level LDH were included. The visual analog scale score (VAS) for leg and back pain, Oswestry Disability Index (ODI) score, and Macnab criteria were evaluated preoperatively and at 2 years postoperatively (final follow-up). Operation time, duration of hospital stay, cost, postoperative complications, and the rates of and reasons for delayed discharge and readmission were recorded and analyzed.The mean operative time was 45.8 ± 8.4 minutes in the PELD-A (nonday surgery mode) group and 41.3 ± 8.7 minutes in the PELD-D (day surgery mode) group (P = .63). The average duration of hospital stay was 2.8 ± 1.1 days in the PELD-A group and 3.2 ± 0.9 hours in the PELD-D group (P < .001). The average hospitalization expenses of the PELD-A and PELD-D groups were 28,090 ± 286 RMB and 24,356 ± 126 RMB (P = .03), respectively. In both groups, the mean VAS and ODI scores improved significantly postoperatively compared with the preoperative scores. The satisfactory result rate was 89.8% in the PELD-D group and 91.0% in the PELD-A group, without a significant difference (P = .68). The delayed discharge rate in the PELD-A and PELD-D groups was 8.20% and 8.43%, respectively (P = .93). The main reasons for delayed discharge were dysesthesia, neurologic deficit, nausea, headache and residential distance from the hospital. The overall readmission rates were 5.99% and 5.53% in the PELD-A and PELD-D groups, respectively (P = .85). The most common reasons for readmission were reherniation, sequestered herniation and pain.In conclusion, PELD is safe and effective for the treatment of LDH and can reduce medical costs as day surgery, and it thus warrants increased attention.

Comparison of the effectiveness and outcome of microendoscopic and open discectomy in patients suffering from lumbar disc herniation

BACKGROUND

The purpose of our study is to compare the outcomes and effectiveness of MED vs OLD for lumbar disc herniation.

OBJECTIVES

To identify the functional outcomes in terms of ODI score, VAS score complications in terms of intraoperative blood loss, use of general anesthesia, and morbidity in terms of total hospital stay between MED and OLD.

METHODS

In our randomized prospective study we analyzed 60 patients with clinical signs and symptoms with 2 weeks of failed conservative treatment plus MRI or CT scan findings of lumbar disc herniation who underwent MED and OLD. The study was undertaken from November 2017 to January 2019 at Guangzhou Medical University of Second Affiliated Hospital, department of orthopedic surgery in spinal Unit, Guangzhou, China. Patients were divided into 2 groups i.e. who underwent MED group and the OLD group then we compared the preoperative and postoperative ODI and VAS score, duration of total hospital stay, intraoperative blood loss, and operation time.

RESULTS

We evaluated 60 patients. Among them, 30 underwent MED (15 female and 15 male) and 30 underwent OLD 14 male 16 female. Surgical and anesthesia time was significantly shorter, blood loss and hospital stay were significantly reduced in patients having MED than OLD (<0.005). The improvement in the ODI in both groups was clinically significant and statistically (P < .005) at postoperative 1st day (with greater improvement in the MED group), at 6 weeks (P > .005), month 6 (>0.005) statistically no significant. The clinical improvement was similar in both groups. VAS and ODI scores improved significantly postoperatively in both groups. However, the MED group was superior to the OLD group with less time in bed, shorter operation time, less blood loss which is clinically and statistically significant (P < .05).

CONCLUSIONS

The standard surgical treatment of lumbar disc herniation has been open discectomy but there has been a trend towards minimally invasive procedures. MED for lumbar spine disc herniation is a well-known but developing field, which is increasingly spreading in the last few years. The success rate of MED is about approximately 90%. Both methods are equally effective in relieving radicular pain. MED was superior in terms of total hospital stay, morbidity, and earlier return to work and anesthetic exposure, blood loss, intra-op time comparing to OLD. MED is a safe and effective alternative to conventional OLD for patients with lumbar disc herniation.

Learning curve and clinical outcomes of percutaneous endoscopic transforaminal decompression for lumbar spinal stenosis

PURPOSE

To define and analyze the learning curve of percutaneous endoscopic transforaminal decompression (PETD) for lumbar spinal stenosis (LSS).

METHODS

From July 2015 to September 2016, 78 patients underwent PETD; one of whom was converted to open surgery, two were lost, and 75 were included in this study. Clinical results were assessed by using the Oswestry Disability Index (ODI) and visual analog scale (VAS). The learning curve was assessed by a logarithmic curve-fitting regression analysis. Of these 75 patients, 35 were defined as the "early" group, and 40 were defined as the "late" group for comparison.

RESULTS

The mean follow-up was 25.37 ± 4.71 months. The median operative time gradually decreased from 95 (interquartile range, IQR, 85-110) minutes for the early group to 70 (IQR, 60-80) minutes for the late group (P < .000), and an asymptote was reached after approximately 35 cases. After surgery, the VAS for leg pain (LP) and ODI decreased significantly and remained constant during the follow-up. However, the VAS of low back pain (LBP) increased mildly. The total complication rate was 6.6%. ODI, VAS of LP and of LBP, and complication rate did not significantly differ between two groups. Early ambulation and short hospital stay after surgery were achieved.

CONCLUSION

The learning curve of PETD for LSS was assessed and good clinical results were achieved. The surgeon's experience with this technique correlated with reduced operation time. Proper patient selection, familiarity with pathological anatomy, and manipulation under endoscopic view may shorten the learning curve and decrease complications.

Comparison of percutaneous transforaminal endoscopic lumbar discectomy through unilateral versus bilateral approach for L3/4 or L4/5 lumbar disc herniation with bilateral symptoms: technical notes and a prospective randomized study

PURPOSE

In this study, the authors described the technical notes of percutaneous transforaminal endoscopic lumbar discectomy (PTELD) through unilateral approach and compared PTELD through unilateral versus bilateral approach for L3/4 or L4/5 lumbar disc herniation with bilateral symptoms.

METHODS

A prospective randomized clinical study was performed from June 2014 to October 2016. A total of 71 patients with lumbar disc herniation (L3/4 or L4/5) and bilateral symptoms were divided randomly into Unilateral-Approach group (n = 35) or Bilateral-Approach group (n = 36). Operation time, blood loss, intraoperative fluoroscopy and recurrences were recorded and analyzed statistically. Visual Analogue Scale scores, Oswestry Disability Index and the MacNab standard were used to analyze the clinical outcomes of the two groups.

RESULTS

The baseline data of the two groups were statistically similar. There was significant postoperative improvement in VAS and ODI scores in both the groups, and clinical outcomes are comparable according to the MacNab standard. However, VAS score of back pain at 1 day after surgery in Unilateral-Approach group was significantly lower than that in Bilateral-Approach group (P < 0.05). Moreover, operation time and cumulative time of intraoperative fluoroscopy of Unilateral-Approach group were significantly shorter than that of Bilateral-Approach group (P < 0.05).

CONCLUSION

For L3/4 or L4/5 LDH with bilateral symptoms, PTELD through unilateral approach is effective, with advantage of shorter operation time, shorter cumulative time of intraoperative fluoroscopy and milder postoperative short-term back pain compared to bilateral approach. These slides can be retrieved under Electronic Supplementary Material.

Removal of calcified lumbar disc herniation with endoscopic-matched ultrasonic osteotome - Our preliminary experience

Objective: To evaluate the clinical efficacy, practicability, and safety of an ultrasonic osteotome for percutaneous transforaminal endoscopic discectomy (PTED) in patients with calcified lumbar disc herniation (CLDH).Methods: A total of 25 CLDH patients who underwent PTED at our department between December 2017 and August 2018 were analyzed retrospectively. Post-operative lumbar spine CT was used to evaluate residual calcification. Efficacy was evaluated by pre- and post-operative with the pain visual analog scale (VAS), Oswestry disability index (ODI), and the Modified MacNab Scale; the incidence of intra- and postoperative complications was also analyzed.Results: All procedures were successfully completed and none of the patients was lost to follow-up. Postoperative CT verified the successful removal of calcified protrusions. VAS and ODI scores improved significantly after surgery. Based on the Modified MacNab scale, >90% patients achieved good or excellent outcomes. There were no complications such as dural tear and infection. Seven patients had varying degrees of postoperative dysesthesia. One patient experienced recurrence of herniation within 1 week after operation; successful recovery was achieved after repeat PTED.Conclusions: Use of this ultrasonic osteotome for PTED facilitated effective removal of calcified disc protrusion, relieved nerve compression, and protected the adjacent neurovascular tissues. The instrument may help expand the indications for endoscopic surgery and avoid open surgery for some CLDH patients.

Predictive Scoring and Risk Factors of Early Recurrence after Percutaneous Endoscopic Lumbar Discectomy

Purpose

To predict the early recurrence after full endoscopic lumbar discectomy, we analyzed factors related to demographic factor anatomical factors, operative method, and postoperative management, and predicted the possibility of recurrence according to the scoring system.

Materials and Methods

In this prospective study, we enrolled 300 patients who underwent 1 out of 3 surgical procedures. The patients were randomized into one of the following groups: group A (n = 100), transforaminal inside-out approach; group B (n = 100), transforaminal outside-in approach; and group C (n = 100), interlaminar approach. The clinical results were evaluated by a visual analogue scale (VAS). Related factors evaluated with points of (A) demographic factors: (1) age, (2) gender, (3) BMI, (B) anatomical factors: (4) disc degeneration scale, (5) modic change, (6) number of involved disc herniation, (7) history of discectomy (first, recurred), (8) herniated disc level, (9) disc height, (10) segmental dynamic motion, (11) disc location, (C) operation factors: (12) annulus preservation along the disc protrusion, (13) approach method (transforaminal inside-out, transforaminal outside-in, interlaminar); (D) postoperative care factors: (14) early ambulation, (15) spinal orthosis (corset) application. Among these, we analyzed statistically significant recurrence risk factors after PELD in all patients and early recurrence predicting score ratio was obtained.

Results

The overall recurrence rate was 9.33%. The recurrence rate was 11%, 10%, and 7% for groups A, B, and C, respectively. Average early recurrence time was 3.26 months. The change in preoperative and postoperative VAS score was from 8.07 to 1.39, 8.34 to 1.34, and 8.14 to 1.86 in groups A, B, and C, respectively. The recurrence rate based on the (1) age was <40 years: 5.22% (6/115), 41–60 years: 16.1% (20/124), and >61 years: 3.07% (2/65); (2) gender was male: 13/139 (9.35%), female: 15/161 (9.32%); (3) BMI was obese: 17.57% (13/74), overweight: 11.6% (9/77), underweight: 6.35% (4/63), and normal weight: 2.33% (2/86); (4) degeneration scale was grades 1–2: 2% (1/50), grade 3: 7.4% (10/135), and grades 4–5: 14.8% (17/115); (5) modic change was type I: 25% (3/12), type II: 14.3% (1/7), type III: 33% (1/3), and no modic change: 8.27% (23/278); (6) number of involved disc herniation was 1 level: 3.9% (5/128), 2 level: 10.4% (13/125), 3 levels: 18.9% (7/37), and 4 levels: 30% (3/10); (7) history of discectomy was first: 8.83% (25/283) and repeated: 17.65% (3/17); (8) herniated disc level was L1–L2/L2–L3/L3–L4: 3.95% (3/76) and L4–L5: 14.6% (18/123); (9) disc height was <80%: 17.14% (6/35), 81%–100%: 8.16% (12/147), and >101%: 8.5% (10/118); (10) segmental dynamic motion was 1–10°: 8.58% (20/233) and 11–20° : 11.9% (8/67); (11) disc location was central: 7.41% (2/27), foraminal: 3.03% (2/66), and inferior/superior/paracentral: 11.59% (24/207); (12) radical annulotomy was 8.05% (7/87) vs. 9.86% (21/213); (13) approach method was transforaminal (inside-out): 11% (11/100), transforaminal (outside-in): 10% (10/100), and interlaminar: 7% (7/100); (14) early ambulation was 16.42% (23/140) vs. 3.13% (5/160); and (15) spinal orthosis application was 7.35% (10/136) vs. 10.98% (18/164). According to the above results, after summation of all scores, the early recurrence predicting score: recurrence rate ratio was 1–4: 0% (0/23), 5–8: 7.1% (13/183), 9–12: 8% (6/75) and 13–16 100% (10/10).

Conclusions

Early recurrence after PELD is associated with several risk factors such as BMI, degeneration scale, combined HNP, and early ambulation. If we use the predicting score, we can postulate the occurrence of early recurrence after PELD. Knowing the predictive factors prior to surgical intervention will allow us to decrease the early recurrence rate after PELD.

Transforaminal percutaneous endoscopic discectomy for lumbar disc herniation in athletes under the local anesthesia

BACKGROUND

Percutaneous endoscopic discectomy (PED) has been reported to be less invasive and effective procedure for lumbar disc herniation (LDH). Damage to the back muscle is considered minimal, which is particularly important for athletes. However, the results of PED for LDH in athletes have not been reported well. The purpose of this study was to evaluate the clinical outcomes of PED for LDH in athletes.

METHODS

We retrospectively analyzed 21 athlete patients with LDH who had undergone PED. All patients received athletic rehabilitation immediately after surgery. The clinical outcomes were evaluated from the visual analogue scale (VAS) for leg pain and low back pain (LBP), the Oswestry Disability Index (ODI), complications and periods of return to sport.

RESULTS

There were 18 men and 3 women, and the mean age at the time of surgery was 22.9 years (range: 15-43 years). The mean VAS scores for leg pain before and after surgery were 64.3 ± 2.7 mm and 12.4 ± 1.4 mm, respectively. The mean VAS scores for LBP before and after surgery were 62.1 ± 2.2 mm and 10.5 ± 1.1 mm, respectively. The mean ODI scores before and after surgery were 31.3 ± 14.0% and 14.6 ± 7.1%, respectively. The VAS for leg pain, as well as the LBP and ODI, significantly improved after surgery. There were no complications related to the surgery. Ninety-five percent (20/21) returned to play sports at the same performance level as before the procedure by an average of 9.2 weeks after PED.

CONCLUSIONS

PED is a minimally invasive and effective procedure for patients with LDH, especially in athletes. Not only the patients' leg pain but also their discogenic LBP improved. PED has the benefits of preservation of normal posterior structures and a faster return to sports.

Trans-foraminal endoscopic uniportal decompression in degenerative lumbar spondylolisthesis: a technical and case report

Background

Degenerative spondylolisthesis is a common spinal pathology. Traditionally, spinal fusion is an accepted standard surgical treatment for listhesis. But fusion is a major intervention with its known pitfalls. With technological progression, minimally invasive spinal fusion (MISF) procedures are becoming mainstream. Percutaneous trans-foraminal endoscopic lumbar discectomy/decompressions (PTELD) without stabilization has many advantages over even a MISF for select group of patients.

Case presentation

In this case report, we describe using a uniportal unilateral trans-foraminal approach (TFA) for stable listhesis with lumbar disc herniation (LDH) causing chronic bilateral radicular symptoms and back pain with acute exacerbation. Under local anesthesia, we used a flat entry for PTELD, which facilitates an approach to both disc sides ventrally and even dorsal aspect lateral recess decompression on the dominant ipsilateral side. No fixation was done. An excellent outcome is obtained immediately at 6 weeks and maintained at 39 months of follow-up.

Conclusion

PTELD is worth considering as an intermediate procedure before fusion is offered in lateral recess stenosis in stable listhesis patients who have consented and understand the progressive cascade of spinal degeneration.

Revision after failed discectomy

PURPOSE

Recurrent lumbar disc herniation is the most common complication after discectomy. Due to the altered anatomy with the presence of scar tissue, the surgical revision of already operated patients could be a surgical challenge.

METHODS

We describe the microsurgical revision technique step by step with the evaluation of our own clinical results in comparison with primary lumbar disc surgeries. The clinical data are based on a clinical register with 2576 recorded primary surgeries (PD) and 592 cases of revisions (RD) with 12- and 24-month follow-up (FU). The intraoperative dura lesion rates of the surgeries between 2016 and 2018 were recorded retrospectively. Data from 894 primary disc surgeries and 117 revisions were evaluated.

RESULTS

The ODI and the VAS for leg and back pain improved in both groups significantly with slightly inferior outcome of the revision group. The ODI improved from 46.3 (PD) and 45.9 (RD), respectively, to 12.6 (PD) and 22.9 (RD) at the 24-month FU. The VAS dropped down as well in both group [VAS back: 47.8 (PD) and 43.9 (RD) to 19.9 and 32.2 at the 24-month FU; VAS leg: 62.9 (PD) and 65.5 (RD) to 15.6 and 26.8 at the 24-month FU]. During the primary interventions, we observed 1.5% (11/894) and during revisions 7.7% (9/117) of dura lesions.

CONCLUSIONS

There is no clear guideline for the surgical treatment of recurrent disc herniations. In most cases, a pure re-discectomy is sufficient and can be performed safely and effectively with the help of a microscope. These slides can be retrieved under Electronic Supplementary Material.

Worldwide research productivity in the field of full-endoscopic spine surgery: a bibliometric study

PURPOSE

To investigate the quantity and quality of articles in the field of full-endoscopic spine surgery (FESS) from different countries and assess characteristics of worldwide research productivity.

METHODS

Articles published from 1997 to July 23, 2018, were screened using the Web of Science database. All studies were assessed for the following parameters: the number of total publications, h-index, contribution of countries, authors, journals, and institutions.

RESULTS

A total of 408 articles were identified between 1997 and 2018. Between 1997 and 2017, the number of published articles tended to increase by 41 times. The largest number of articles was from China (30.15%), followed by South Korea (28.68%), the USA (13.97%), Germany (9.31%), and Japan (4.90%). The highest h-index was found for articles from South Korea (23), followed by the USA (18), Germany (16), China (11), and Japan (7). The highest number of articles was published in World Neurosurgery (12.50%), followed by Pain Physician (10.29%), Spine (6.62%), European Spine Journal (4.66%), and Journal of Neurosurgery: Spine (4.17%). Wooridul Spine Hospital published the largest number of articles (10.29%), followed by Tongji University (5.88%), University of Witten/Herdecke (5.39%), Brown University (5.15%), and Third Military Medical University (3.43%).

CONCLUSIONS

The number of articles published in the field of FESS has increased rapidly in the past 20 years. In terms of quantity, China is the most contributive country based on the number of publications. High-quality papers as measured by h-index and the large quantity is from South Korea (second only to China). These slides can be retrieved under Electronic Supplementary Material.

[Minimally invasive decompression techniques for spinal cord stenosis]

BACKGROUND

Lumbar spinal canal stenosis is frequently found among elderly patients and significantly limits their quality of life. Non-surgical therapy is an initial treatment option; however, it does not eliminate the underlying pathology. Surgical decompression of the spinal canal has now become the treatment of choice.

OBJECTIVE

Minimalization of surgical approach strategies with maintaining sufficient decompression of the spinal canal and avoiding disadvantages of macrosurgical techniques, monolateral paravertebral approach with bilateral intraspinal decompression, specific surgical techniques.

MATERIALS AND METHODS

Minimally invasive decompression techniques using a microscope or an endoscope are presented and different surgical strategies depending on both the extent (mono-, bi-, and multisegmental) and the location of the stenosis (intraspinal central, lateral recess, foraminal) are described.

RESULTS

Minimally invasive microscopic or endoscopic decompression procedures enable sufficient widening of the spinal canal. Disadvantages of macrosurgical procedures (e. g., postoperative instability) can be avoided. The complication spectrum overlaps partially with that of macrosurgical interventions, albeit with significantly less marked severity. Subjective patient outcome is clearly improved.

CONCLUSIONS

Referring to modern minimally invasive decompression procedures, surgery of lumbar spinal canal stenosis represents a rational and logical treatment alternative, since causal treatment of the pathology is only possible with surgery.

The Long-term Reoperation Rate Following Surgery for Lumbar Herniated Intervertebral Disc Disease: A Nationwide Sample Cohort Study With a 10-year Follow-up

STUDY DESIGN

A retrospective cohort study of a nationwide sample database.

OBJECTIVE

The objective of the present study was to compare the long-term incidence of reoperation for lumbar herniated intervertebral disc disease (HIVD) after major surgical techniques (open discectomy, OD; laminectomy; percutaneous endoscopic lumbar discectomy, PELD; fusion).

SUMMARY OF BACKGROUND DATA

HIVD is a major spinal affliction; if the disease is intractable, surgery is recommended. Considering both the aging of patients and the chronicity of lumbar degenerative disease, the effect of surgical treatment for the lumbar spine should be durable for as long as possible.

METHODS

The National Health Insurance Service-National Sample Cohort (NHIS-NSC) of Republic of Korea was utilized to establish a cohort of adult patients (N = 1856) who underwent first surgery for lumbar HIVD during 2005 to 2007. Patients were followed for 8 to 10 years. Considering death before reoperation as a competing event, reoperation hazards were compared among surgical techniques using the Fine and Gray regression model after adjustment for age, gender, Charlson comorbidity score, osteoporosis, diabetes, the severity of disability, insurance type, and hospital type.

RESULTS

The overall cumulative incidences of reoperation were 4% at 1 year, 6% at 2 years, 8% at 3 years, 11% at 5 years, and 16% at 10 years. The cumulative incidences of reoperation were 16%, 14%, 16%, and 10% after OD, laminectomy, PELD, and fusion, respectively, at 10 years postoperation, with no difference among the surgical techniques. However, the distribution of reoperation types was significantly different according to the first surgical technique (P < 0.01). OD was selected as the reoperation surgical technique in 80% of patients after OD and in 81% of patients after PELD.

CONCLUSION

The probability of reoperation did not differ among OD, laminectomy, PELD, and fusion during the 10-year follow-up period. However, OD was the most commonly used technique in reoperation.

LEVEL OF EVIDENCE

4.

Surgical treatment of cervical subaxial intraspinal extradural cysts using a full-endoscopic uniportal posterior approach

PURPOSE

Symptomatic intraspinal extradural cysts of the cervical subaxial spine are rare, but usually require surgery. Conventional posterior decompression is the gold standard. However, there is increasing experience with endoscopic surgical techniques. The purpose of the study is to evaluate the technical implementation and outcomes of a full-endoscopic uniportal technique via the posterior approach in patients with symptomatic intraspinal extradural cysts of the cervical subaxial spine.

METHODS

Seven consecutive patients with a subaxial location of symptomatic intraspinal extradural cysts were decompressed in a full-endoscopic uniportal technique via the posterior approach between 2009 and 2015. Imaging and clinical data were collected in follow-up examinations for 18 months.

RESULTS

In all cases, the cyst was completely removed and adequate decompression was achieved using the full-endoscopic uniportal technique. One patient developed a dural leak that was sutured and covered intraoperatively. No other complications requiring treatment were observed. All patients had a good clinical outcome with stable regression of the radicular and central nerve pain or neurological deficits. The imaging follow-up showed sufficient decompression in all cases. No evidence was found of increasing instability during the follow-up period.

CONCLUSION

The full-endoscopic uniportal operation with a posterior approach allows the resection of the cyst and can minimize trauma and destabilization and has technical benefits and a low complication rate. It is an alternative surgical method that can offer advantages and is considered by the authors to be the surgical technique of choice for cervical subaxial intraspinal extradural cysts.

Percutaneous endoscopic lumbar discectomy and microsurgical laminotomy : A prospective, randomized controlled trial of patients with lumbar disc herniation and lateral recess stenosis

BACKGROUND

Sufficient decompression of the nerve root canal is still regarded as the method of choice when operating on patients with lumbar disc herniation (LDH) with lumbar lateral recess stenosis; however, tissue-sparing procedures are becoming more popular. Endoscopic techniques offer advantages and the benefits of rehabilitation, which have become the standard in many surgical operations when operating on the spine. A significant issue has been the upgrading of instruments to provide enough bone resection under continuous visual control.

MATERIAL AND METHODS

We examined patients who had LDH with lateral recess stenosis and compared the results of nerve root canal decompression using percutaneous endoscopic lumbar discectomy (PELD) with a microsurgical laminotomy (ML) technique. In this study 40 patients with full endoscopic decompression or microsurgery were followed up for 2 years. In addition to general and specific parameters, the following two parameters were also used for the investigation: the Visual Analog Scale (VAS) and the Oswestry Disability Index (ODI).

RESULTS

Except for 1 patient in whom repair was done by fusion and 1 who was lost to follow-up, 38 patients remained in the study over the 2 years. The mean operating time in the PELD group was longer (p < 0.05), but intraoperative and postoperative blood loss was less than in the ML group (p < 0.05). The postoperative results were better than before surgery, and the VAS and ODI parameters indicated a clear improvement in leg pain and daily activities in both groups (p > 0.05). Of the patients three suffered increasing back pain (2 ML, 1 PELD).

CONCLUSION

The results indicated that the PELD can provide an effective supplement and serve as an alternative for LDH with lateral recess stenosis compared with the ML technique when the indication criteria are fulfilled. The PELD also has the advantage of being a minimally invasive intervention.

Outcomes of endoscopic discectomy compared with open microdiscectomy and tubular microdiscectomy for lumbar disc herniations: a meta-analysis

OBJECTIVE

Endoscopic discectomy (ED) has been advocated as a less-invasive alternative to open microdiscectomy (OM) and tubular microdiscectomy (TM) for lumbar disc herniations, with the potential to decrease postoperative pain and shorten recovery times. Large-scale, objective comparisons of outcomes between ED, OM, and TM, however, are lacking. The authors' objective in this study was to conduct a meta-analysis comparing outcomes of ED, OM, and TM.

METHODS

The PubMed database was searched for articles published as of February 1, 2019, for comparative studies reporting outcomes of some combination of ED, OM, and TM. A meta-analysis of outcome parameters was performed assuming random effects.

RESULTS

Twenty-six studies describing the outcomes of 2577 patients were included. Estimated blood loss was significantly higher with OM than with both TM (p = 0.01) and ED (p < 0.00001). Length of stay was significantly longer with OM than with ED (p < 0.00001). Return to work time was significantly longer in OM than with ED (p = 0.001). Postoperative leg (p = 0.02) and back (p = 0.01) VAS scores, and Oswestry Disability Index scores (p = 0.006) at latest follow-up were significantly higher for OM than for ED. Serum creatine phosphokinase (p = 0.02) and C-reactive protein (p < 0.00001) levels on postoperative day 1 were significantly higher with OM than with ED.

CONCLUSIONS

Outcomes of TM and OM for lumbar disc herniations are largely equivalent. While this analysis demonstrated that several clinical variables were significantly improved in patients undergoing ED when compared with OM, the magnitude of many of these differences was small and of uncertain clinical relevance, and several of the included studies were retrospective and subject to a high risk of bias. Further high-quality prospective studies are needed before definitive conclusions can be drawn regarding the comparative efficacy of the various surgical treatments for lumbar disc herniations.

Minimally Invasive versus Open Spine Surgery: What Does the Best Evidence Tell Us?

Background:

Spine surgery has been transformed significantly by the growth of minimally invasive surgery (MIS) procedures. Easily marketable to patients as less invasive with smaller incisions, MIS is often perceived as superior to traditional open spine surgery. The highest quality evidence comparing MIS with open spine surgery was examined.

Methods:

A systematic review of randomized controlled trials (RCTs) involving MIS versus open spine surgery was performed using the Entrez gateway of the PubMed database for articles published in English up to December 28, 2015. RCTs and systematic reviews of RCTs of MIS versus open spine surgery were evaluated for three particular entities: Cervical disc herniation, lumbar disc herniation, and posterior lumbar fusion.

Results:

A total of 17 RCTs were identified, along with six systematic reviews. For cervical disc herniation, MIS provided no difference in overall function, arm pain relief, or long-term neck pain. In lumbar disc herniation, MIS was inferior in providing leg/low back pain relief, rehospitalization rates, quality of life improvement, and exposed the surgeon to >10 times more radiation in return for shorter hospital stay and less surgical site infection. In posterior lumbar fusion, MIS transforaminal lumbar interbody fusion (TLIF) had significantly reduced 2-year societal cost, fewer medical complications, reduced time to return to work, and improved short-term Oswestry Disability Index scores at the cost of higher revision rates, higher readmission rates, and more than twice the amount of intraoperative fluoroscopy.

Conclusion:

The highest levels of evidence do not support MIS over open surgery for cervical or lumbar disc herniation. However, MIS TLIF demonstrates advantages along with higher revision/readmission rates. Regardless of patient indication, MIS exposes the surgeon to significantly more radiation; it is unclear how this impacts patients. These results should optimize informed decision-making regarding MIS versus open spine surgery, particularly in the current advertising climate greatly favoring MIS.

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.

Full-Endoscopic Visualized Foraminoplasty and Discectomy Under General Anesthesia in the Treatment of L4-L5 and L5-S1 Disc Herniation

STUDY DESIGN

Retrospective analysis of clinical records.

OBJECTIVE

The aim of this study is to evaluate the clinical outcomes and neurological complications of full-endoscopic visualized foraminoplasty and discectomy under general anesthesia for the treatment of L4-L5 and L5-S1 disc herniation.

SUMMARY OF BACKGROUND DATA

Full-endoscopic visualized foraminoplasty and discectomy, which is our newly developed technique, has been used in the treatment of lumbar disc herniation and lumbar spinal stenosis. While the clinical effect, safety, and neurological complications of full-endoscopic visualized foraminoplasty and discectomy under general anesthesia are still uncertain.

METHODS

Between May 2015 and April 2017, 84 patients with lumbar disc herniation were included, and categorized into L4-L5 group and L5-S1 group according to the discectomy segment. Full-endoscopic visualized foraminoplasty and discectomy was performed under general anesthesia. Operative time, fluoroscopy time, hospitalization time, and complications were recorded. Each patient included was followed for at least 12 months. Visual analog scale score for leg and back pain and Oswestry Disability Index score were evaluated preoperatively and at 3, 6, and 12 months postoperatively. The modified MacNab criteria were also used to evaluate surgical effectiveness.

RESULTS

The mean operative time, fluoroscopy time, and hospitalization time at L4-L5 and L5-S1 were of no significant difference. The mean visual analog scale and Oswestry Disability Index postoperative scores were significantly improved over the preoperative scores. Intraoperative nerve injury occurred in one case at L4-L5, with a neurological complication rate of 2.1% in L4-L5 group. One case at L4-L5 suffered recurrence 2 weeks after the surgery, resulting in a recurrence rate of 2.1% in L4-L5 group. This recurrence case was treated by a second full-endoscopic visualized foraminoplasty and discectomy under general anesthesia.

CONCLUSION

Full-endoscopic visualized foraminoplasty and discectomy under general anesthesia is efficient and safe for the treatment of L4-L5 and L5-S1 disc herniation.

LEVEL OF EVIDENCE

4.

Trends in Incidence and Treatment of Herniated Lumbar Disc in Republic of Korea : A Nationwide Database Study

OBJECTIVE

This study aimed to determine the incidence and analyze trends of the herniated lumbar disc (HLD) based on a national database in the Republic of Korea (ROK) from January 2008 to December 2016.

METHODS

This study was a retrospective analysis of data obtained from the national health-claim database provided by the National Health Insurance Service for 2008-2016 using the International Classification of Diseases. The crude incidence and age-standardized incidence of HLD were calculated, and additional analysis was conducted according to age and sex. Changes in trends in treatment methods and some treatments were analyzed using the Korean Classification of Diseases procedure codes.

RESULTS

The number of patients diagnosed with HLD was 472245 in 2008 and increased to 537577 in 2012; however, it decreased to 478697 in 2016. The pattern of crude incidence and the standardized incidence were also similar. Overall, the incidence of HLD increased annually for the 30s, 40s, 50s, and 70s until 2012 and then decreased. However, the incidence of HLD for the 80s continued to increase. The crude incidence of HLD in female patients exceeded that of male patients in their middle age (30s or 40s) and was 1.5-1.6 times higher than in male patients in their 60s. The total number of open discectomy (OD) increased from 71598 in 2008 to 93942 in 2012 and then decreased to 85846 in 2016. The rate of younger patients (the 20s, 30s, and 40s) who underwent OD was decreased, and the rate of younger patients who underwent percutaneous endoscopic lumbar discectomy was increased. However, the rate of older patients (the 70s and 80s) who underwent OD was continuously increased.

CONCLUSION

This nationwide data on HLD from 2008 to 2016 in the ROK demonstrated that the crude incidence and the standardized incidence increased until 2012 and then decreased. The annual crude incidence was different according to age and sex. These findings may be considered when deciding future health policy, especially in countries with a similar national health insurance system (or with plans to adopt).

Revision Surgery after Percutaneous Endoscopic Transforaminal Discectomy Compared with Primary Open Surgery for Symptomatic Lumbar Degenerative Disease

Objective

To evaluate the clinical outcome of reoperation after percutaneous endoscopic lumbar discectomy (PELD) as compared with primary spinal decompression and fusion.

Methods

A retrospective study from December 2014 to December 2017 was conducted at Peking Union Medical College Hospital and comprised 39 patients with symptomatic lumbar degenerative disease (LDD): 13 post‐PELD who underwent reoperation (revision surgery group) and 26 who received primary spinal decompression and fusion (primary open surgery group). The two groups were compared regarding: operative time, blood loss, transfusion, hospitalization, postoperative visual analog scale (VAS) scores, Oswestry Disability Index (ODI) scores, Japanese Orthopedic Association (JOA) improvement rate, and postoperative complications. The Mann–Whitney U‐test was applied to analyze continuous parameters, and the χ²‐test for categorical parameters. Fisher's exact test was used for small data subsets.

Results

There was no statistically significant difference between the two groups in mean age (52.7 years vs 52.9 years), gender ratio (6 men‐to‐7 women vs 12 men‐to‐14 women), body mass index, medical history, preoperative diagnosis, or surgical spine level (P > 0.05). The mean operative time of the revision surgery group was significantly longer than that of the primary open surgery group (160.0 min vs 130.2 min, P < 0.05). The revision surgery group also had a significantly higher mean estimated blood loss, postoperative drainage, and length of hospital stay (P < 0.05). However, no significant differences were found between the two groups in terms of hemoglobin and hematocrit values, preoperatively and postoperatively. The rate of transitional neurological irritation was higher in the revision surgery group (61.5% vs 3.8%; P < 0.05), as was intraoperative durotomy and cerebrospinal fluid leakage (30.8% vs 3.8%, P < 0.05). At 1 month, the VAS and ODI scores of the primary open surgery group were significantly better than those of the revision surgery group, while the improvement in JOA scores was similar. After 6 and 12 months’ follow‐up, the VAS and ODI scores and the rates of JOA improvement were comparable.

Conclusion

Patients with LDD who received primary spinal decompression and fusion experienced lower rates of perioperative complications and shorter hospitalization compared with patients who underwent revision surgery after PELD, but the clinical outcomes at the last follow‐up of both groups were satisfactory.

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

OBJECTIVES

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSION

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

[Percutaneous Lumbar Endoscopic Discectomy: Presentation of 60 Cases Intervened in Argentina with Awake Patients]

INTRODUCTION

Percutaneous endoscopic lumbar discectomy (PELD) is a minimally invasive technique that has been used in different countries since the late eighties for the treatment of herniated discs.

OBJECTIVE

The objective of this study was to describe the results of PELD in a series of awake patients, treated with epidural anesthesia and mild sedation.

MATERIALS AND METHODS

In a group of 60 patients, who together had 77 discs operated on between April 2016 and March 2018, data were collected on patient age and gender, clinical presentation, and MRI abnormalities. The main outcome of interest was the difference between preoperative and postoperative Oswestry (Oswestry disability index [ODI]) scores 8 weeks after the procedure. Macnab criteria, operation duration, length of hospitalization, surgical complications, and the need for reoperation were other outcomes evaluated. All patients received epidural anesthesia and mild sedation.

RESULTS

The average reduction in ODI at 8 weeks was 48 points (standard deviation [SD] = 5), representing an average percentage reduction of 85% (SD = 8). By Macnab's criteria, 85% of patients experienced either an excellent or good result, while 10% and 5% had a fair and poor result, respectively. Average surgery time was 50 min and in-hospitalization stay 8.6 h.

CONCLUSIONS

In our series of surgical patients with lumbar disc herniations, PELD yielded very good results, manifest as significantly reduced pain, brief procedural durations, no complications, and short hospital stays. Patients accepted the option of being awake and immediately ambulatory, and the approach proved highly feasible to execute.