Complications and Management of Endoscopic Spinal Surgery

Trends in degenerative lumbar spinal surgery during the early COVID-19 pandemic in Republic of Korea: A national study utilizing the national health insurance database

During the first year of the COVID-19 pandemic, the Republic of Korea (ROK) experienced three epidemic waves in February, August, and November 2020. These waves, combined with the overarching pandemic, significantly influenced trends in spinal surgery. This study aimed to investigate the trends in degenerative lumbar spinal surgery in ROK during the early COVID-19 pandemic, especially in relation to specific epidemic waves. Using the National Health Information Database in ROK, we identified all patients who underwent surgery for degenerative lumbar spinal diseases between January 1, 2019 and December 31, 2020. A joinpoint regression was used to assess temporal trends in spinal surgeries over the first year of the COVID-19 pandemic. The number of surgeries decreased following the first and second epidemic waves (p<0.01 and p = 0.34, respectively), but these were offset by compensatory increases later on (p<0.01 and p = 0.05, respectively). However, the third epidemic wave did not lead to a decrease in surgical volume, and the total number of surgeries remained comparable to the period before the pandemic. When compared to the pre-COVID-19 period, average LOH was reduced by 1 day during the COVID-19 period (p<0.01), while mean hospital costs increased significantly from 3,511 to 4,061 USD (p<0.01). Additionally, the transfer rate and the 30-day readmission rate significantly decreased (both p<0.01), while the reoperation rate remained stable (p = 0.36). Despite the impact of epidemic waves on monthly surgery numbers, a subsequent compensatory increase was observed, indicating that surgical care has adapted to the challenges of the pandemic. This adaptability, along with the stable total number of operations, highlights the potential for healthcare systems to continue elective spine surgery during public health crises with strategic resource allocation and patient triage. Policies should ensure that surgeries for degenerative spinal diseases, particularly those not requiring urgent care but crucial for patient quality of life, are not unnecessarily halted.

Unilateral Biportal Endoscopic Discectomy versus Percutaneous Endoscopic Interlaminar Discectomy for Lumbar Disc Herniation

Background

As the latest endoscopic spine surgery, percutaneous endoscopic interlaminar discectomy (PEID) and unilateral biportal endoscopic (UBE) discectomy have distinct technical characteristics. This study aimed to evaluate the clinical outcomes of PEID and UBE discectomy in the treatment of single-level lumbar disc herniation (LDH).

Methods

Between February 2019 and April 2022, 115 patients with single-level LDH at L4-5 or L5-S1 received PEID or UBE discectomy. The patients were separated into two groups based on the surgical method used: Group 1 (the PEID group) (n = 60) and Group 2 (the UBE group) (n = 55). Various parameters, including operative time, hospitalization time, fluoroscopy frequency, total costs, complications, visual analogue scale (VAS), and Oswestry Disability Index (ODI), were evaluated and compared between the two groups.

Results

There were no significant differences in the VAS and ODI scores in 12 months after the operation between two groups (P > 0.05). However, the VAS of lower back pain on the first day after the operation in Group 2 (2.53±0.89) was higher than that in Group 1 (2.19±0.74) (P < 0.05). There were no significant differences in the operation time and incidence of complications between two groups (P > 0.05). But total costs in Group 2 (43,121±4280) were significantly higher than those in Group 1 (30,069±3551) (P < 0.05).

Conclusion

Both UBE and PEID procedures have similar efficacy in alleviating pain and improving functional ability in patients with LDH. However, UBE surgery results in higher costs than PEID surgery.

Intra-Examiner Reliability and Validity of Sagittal Cervical Spine Mensuration Methods Using Deep Convolutional Neural Networks

Background: The biomechanical analysis of spine and postural misalignments is important for surgical and non-surgical treatment of spinal pain. We investigated the examiner reliability of sagittal cervical alignment variables compared to the reliability and concurrent validity of computer vision algorithms used in the PostureRay® software 2024. Methods: A retrospective database of 254 lateral cervical radiographs of patients between the ages of 11 and 86 is studied. The radiographs include clearly visualized C1-C7 vertebrae that were evaluated by a human using the software. To evaluate examiner reliability and the concurrent validity of the trained CNN performance, two blinded trials of radiographic digitization were performed by an extensively trained expert user (US) clinician with a two-week interval between trials. Then, the same clinician used the trained CNN twice to reproduce the same measures within a 2-week interval on the same 254 radiographs. Measured variables included segmental angles as relative rotation angles (RRA) C1-C7, Cobb angles C2-C7, relative segmental translations (RT) C1-C7, anterior translation C2-C7, and absolute rotation angle (ARA) C2-C7. Data were remotely extracted from the examiner's PostureRay® system for data collection and sorted based on gender and stratification of degenerative changes. Reliability was assessed via intra-class correlations (ICC), root mean squared error (RMSE), and R2 values. Results: In comparing repeated measures of the CNN network to itself, perfect reliability was found for the ICC (1.0), RMSE (0), and R2 (1). The reliability of the trained expert US was in the excellent range for all variables, where 12/18 variables had ICCs ≥ 0.9 and 6/18 variables were 0.84 ≤ ICCs ≤ 0.89. Similarly, for the expert US, all R2 values were in the excellent range (R2 ≥ 0.7), and all RMSEs were small, being 0.42 ≤ RMSEs ≤ 3.27. Construct validity between the expert US and the CNN network was found to be in the excellent range with 18/18 ICCs in the excellent range (ICCs ≥ 0.8), 16/18 R2 values in the strong to excellent range (R2 ≥ 0.7), and 2/18 in the good to moderate range (R2 RT C6/C7 = 0.57 and R2 Cobb C6/C7 = 0.64. The RMSEs for expert US vs. the CNN network were small, being 0.37 ≤ RMSEs ≤ 2.89. Conclusions: A comparison of repeated measures within the computer vision CNN network and expert human found exceptional reliability and excellent construct validity when comparing the computer vision to the human observer.

Percutaneous Endoscopic Suprapedicular Decompression in the Treatment of Down-Migrated Lumbar DiscHerniation

OBJECTIVE

This study aimed to investigate the clinical efficacy of percutaneous endoscopic suprapedicular decompression in treatment of down-migrated lumbar disc herniation.

METHODS

The clinical data of 43 patients with down-migrated lumbar disc herniation treated with endoscopic surgery at our hospital between January 2022 and January 2023 were retrospectively analyzed. Twenty-two and 21 patients underwent percutaneous endoscopic decompression using the suprapedicular and transforaminal endoscopic surgical system approaches, respectively. The perioperative, follow-up, and imaging data of the groups were compared.

RESULTS

Surgery was uneventful in both groups. The number of intraoperative fluoroscopies and duration of surgery were significantly lower in the suprapedicular group (P < 0.05). The patients in both groups were followed up for at least 12 months. At the last follow-up, lumbar pain and leg pain visual analog scale, Oswestry Disability Index, and 36-Item Short Form Health Survey scores were significantly improved in both groups compared with preoperative values (P < 0.05); the differences in these indexes between the 2 groups were not significant preoperatively (P > 0.05). However, at the last postoperative follow-up, lumbar pain visual analog scale scores were significantly better in the suprapedicular group (0.83 ± 0.85 vs. 2.54 ± 1.32, P < 0.05). There was no significant change in intervertebral space height or lumbar lordotic angle compared with preoperative values in either group at the last follow-up (P > 0.05). However, the spinal canal cross-sectional area significantly increased (P < 0.05).

CONCLUSIONS

The treatment of down-migrated lumbar disc herniation via a suprapedicular approach enabled the incision of the superior margin of the pedicle as needed under direct vision, involved less fluoroscopy while preserving facet joint stability, and enabled targeted removal of the herniated nucleus pulposus, thus greatly reducing residual nucleus pulposus. This surgical procedure was safe, rapid, and showed satisfactory therapeutic efficacy.

Comparing the Efficacy and Safety of Unilateral Biportal Endoscopic Decompression with Percutaneous Endoscopic Lumbar Decompression for Lumbar Degenerative Diseases: A Meta-Analysis

OBJECTIVE

Unilateral biportal endoscopic decompression (UBED) offers the advantages of minimal tissue damage, operational flexibility, and clear visualization, positioning it as an innovative and minimally invasive endoscopic technique. Nevertheless, the clinical evidence supporting the use of UBED in the treatment of degenerative lumbar diseases is limited and conflicting.

METHODS

As of October 1, 2023, a comprehensive search was conducted across databases including Web of Science, PubMed, Embase, and the Cochrane Library to identify all published studies on minimally invasive UBED for the treatment of degenerative lumbar diseases. Data pertaining to patient demographics, fluoroscopy time, operative duration, intraoperative hemorrhage, hospitalization length, visual analog scale (VAS) score for back and leg pain, MacNab criteria, Oswestry Disability Index (ODI), and complication rates were extracted. The Newcastle-Ottawa scale was utilized to assess the quality.

RESULTS

Twelve articles were included, involving 816 patients. The back VAS score (95% confidence interval [CI]: -0.09-0.07, P = 0.75), MacNab criteria (95% CI: 0.52-2.3, P = 0.82), fluoroscopy time (95% CI: -7.03 to -0.4, P = 0.08), and the incidence of complications (95% CI: 0.5-1.73, P = 0.82) were not significantly different, while the leg VAS score (95% CI: 0.01-0.18, P = 0.03), ODI score (95% CI: -1.03 to -0.09, P = 0.02), operation time (95% CI: 5.76-20.62, P = 0.0005), hospitalization length (95% CI: 0.41-2.76, P = 0.008), and intraoperative hemorrhage (95% CI: 21.92-72.44, P = 0.0003) were significantly different.

CONCLUSIONS

UBED offers superiority in ODI, flexibility, and visual field clarity. Conversely, percutaneous endoscopic lumbar decompression presents advantages in terms of operation duration, blood loss, hospitalization length, and leg VAS score. These factors should be thoroughly considered when selecting a surgical approach.

Evolution of Cervical Endoscopic Spine Surgery: Current Progress and Future Directions-A Narrative Review

Cervical endoscopic spine surgery is rapidly evolving and gaining popularity for the treatment of cervical radiculopathy and myelopathy. This approach significantly reduces muscular damage and blood loss by minimizing soft tissue stripping, leading to less postoperative pain and a faster postoperative recovery. As scientific evidence accumulates, the efficacy and safety of cervical endoscopic spine surgery are continually affirmed. Both anterior and posterior endoscopic approaches have surfaced as viable alternative treatments for various cervical spine pathologies. Newer techniques, such as endoscopic-assisted fusion, the anterior transcorporeal approach, and unilateral laminotomy for bilateral decompression, have been developed to enhance clinical outcomes and broaden surgical indications. Despite its advantages, this approach faces challenges, including a steep learning curve, increased radiation exposure for both surgeons and patients, and a relative limitation in addressing multi-level pathologies. However, the future of cervical endoscopic spine surgery is promising, with potential enhancements in clinical outcomes and safety on the horizon. This progress is fueled by integrating advanced imaging and navigation technologies, applying regional anesthesia for improved and facilitated postoperative recovery, and incorporating cutting-edge technologies, such as augmented reality. With these advancements, cervical endoscopic spine surgery is poised to broaden its scope in treating cervical spine pathologies while maintaining the benefits of minimized tissue damage and rapid recovery.

Correlation between Disc Imaging Observations and Clinical Efficacy after Percutaneous Endoscopic Lumbar Discectomy: A 1-Year Follow-up Study

OBJECTIVE

The connection between alterations in the disc structure following percutaneous endoscopic lumbar discectomy (PELD) and symptoms in patients postsurgery has not been reported yet. The purpose of the present study was to discuss the potential correlation between the changes in the morphological characteristics of various reference surfaces of the intervertebral disc after percutaneous endoscopic lumbar discectomy (PELD) and clinical outcomes, to identify the morphological parameters that affect efficacy and provide an evidence-based foundation for assessing postoperative efficacy.

METHODS

From October 2019 to October 2021, after percutaneous endoscopic lumbar discectomy (PELD), 98 individuals were enrolled. MRI DICOM data of the lumbar spine were obtained before and after surgery, specifically around 3 months. The morphological parameters of the operated and adjacent segments of the discs were measured using T2-weighted images from three reference planes. Outcomes were assessed using the Oswestry disability index (ODI), visual analogue pain scores for the back and leg (VAS-back/VAS-leg), Japanese Orthopaedic Association (JOA) scores, and recovery rates. Postoperative changes in disc parameters and outcomes were compared between patients with different severity and types of LDH based on the MSU staging. Patients completed the questionnaire during outpatient follow-up appointments 3, 6, and 12 months after the surgery. The follow-up period was 14.69 ± 4.21 months, ranging from 12 to 24 months.

RESULTS

Parameters such as area and circumference of intervertebral discs in the cross-section were not associated with the change in the efficacy index. Postoperatively, a negative correlation between the variation of the disc height, disc height index, and protrusion distance and the difference in VAS scores for low back pain at 3 and 6 months was observed among the two sagittal change parameters. Differences between changes in disc imaging parameters and postoperative efficacy were not statistically significant between various types of lumbar disc herniation.

CONCLUSION

For the patients after percutaneous endoscopic lumbar discectomy, the changes in parameters such as disc area and circumference in the cross-sectional plane are not associated with efficacy, and the changes in disc height and herniation distance in the sagittal plane provide a morphologic basis for the assessment of short-term postoperative efficacy. In addition, the changes in disc morphologic parameters and postoperative efficacy do not differ between various types of lumbar disc herniation.

Predictors of Clinical Failure after Endoscopic Lumbar Spine Surgery During the Initial Learning Curve

OBJECTIVE

This study aims to identify clinical factors that may predict failed endoscopic lumbar spine surgery to guide surgeons with patient selection during the initial learning curve.

METHODS

This is an Australasian prospective analysis of the first 105 patients to undergo lumbar endoscopic spine decompression by 3 surgeons. Modified MacNab outcomes, visual analog scale (VAS) and Oswestry Disability Index (ODI) scores were utilized to evaluate clinical outcomes at 6 months postoperatively. Descriptive statistics and ANOVA t tests were performed to measure statistically significant (P < 0.05) associations between variables using GraphPad Prism v10.

RESULTS

Patients undergoing endoscopic lumbar surgery via an interlaminar or transforaminal approach have overall good/excellent modified MacNab outcomes and a significant reduction in postoperative VAS and ODI scores. Regardless of the anatomic location of disc herniations, good/excellent modified MacNab outcomes and significant reductions in VAS and ODI were reported post-operatively, however, not in patients with calcified disc herniations. Patients with central and foraminal stenosis overall reported poor/fair modified MacNab outcomes, however, there were significant reductions in VAS and ODI scores postoperatively. Patients with subarticular stenosis or an associated spondylolisthesis reported good/excellent modified MacNab outcomes and significant reductions in VAS and ODI scores postoperatively. Patients with disc herniation and concurrent degenerative stenosis had generally poor/fair modified MacNab outcomes.

CONCLUSIONS

The outcomes of endoscopic spine surgery are encouraging with low complication and reoperation rates. However, patients with calcified disc herniations, central canal stenosis, or disc herniation with concurrent degenerative stenosis present challenges during the initial learning curve and may benefit from traditional open or other minimally invasive techniques.

The Evolution of Spinal Endoscopy: Design and Image Analysis of a Single-Use Digital Endoscope Versus Traditional Optic Endoscope

Spinal endoscopy has evolved significantly since its inception, offering minimally invasive solutions for various spinal pathologies. This study introduces a promising innovation in spinal endoscopy-a single-use digital endoscope designed to overcome the drawbacks of traditional optic endoscopes. Traditional endoscopes, despite their utility, present challenges such as fragility, complex disinfection processes, weight issues, and susceptibility to mechanical malfunctions. The digital endoscope, with its disposable nature, lighter weight, and improved image quality, aims to enhance surgical procedures and patient safety. The digital endoscope system comprises a 30-degree 1000 × 1000 pixel resolution camera sensor with a 4.3 mm working channel, and LED light sources replacing optical fibers. The all-in-one touch screen tablet serves as the host computer, providing portability and simplified operation. Image comparisons between the digital and optic endoscopes revealed advantages in the form of increased field of view, lesser distortion, greater close-range resolution, and enhanced luminance. The single-use digital endoscope demonstrates great potential for revolutionizing spine endoscopic surgeries, offering convenience, safety, and superior imaging capabilities compared to traditional optic endoscopes.

Near infrared imaging system for preventing blood vision obstruction in endoscopy

Spinal endoscopy procedure is commonly used in the diagnosis and treatment of various health problems and is effective. Bleeding is one of the most common complications of spinal endoscopy procedures. Blood vision obstruction (BVO), that is, obstruction of the endoscopic camera lens caused by the accumulation of blood in the surgical field, is a serious problem in endoscopic procedures. This study presents what we believe to be a new approach to addressing BVO with external multispectral imaging. The study was completed using a BVO simulation model, and the results reveal that this technology can be used to effectively overcome BVO and provide clear images of the anatomy, enabling more effective diagnosis and treatment. This technique may enable improvement of the outcomes of endoscopic procedures and could have far-reaching implications in the field of endoscopy.

Surgical Technique of Central and Over-the-Top Full-Endoscopic Decompression of the Cervical Spine: A Technical Note

Endoscopic surgery of the cervical spine is constantly evolving and the spectrum of its indications has expanded in recent decades. Full-endoscopic techniques have standardized the procedures for posterior and anterior access. The full-endoscopic approach was developed to treat degenerative diseases with the least possible invasion and without causing instability of the cervical spine. The posterior full-endoscopic approach is indicated for the treatment of diseases of the lateral part of the vertebral segment, such as herniations and stenoses of the lateral recess and vertebral foramen. There has been little discussion of this approach to the treatment of central stenosis of the cervical spine. This technical note describes a step-by-step surgical technique for central and over-the-top full-endoscopic decompression in the cervical spine, using a 3.7 mm working channel endoscope. This technique has already been shown to be effective in a recent case series with a 4.7 mm working channel endoscope, and may represent a new treatment option for central or bilateral lateral recess stenosis. There is also the possibility of a bilateral full-endoscopic approach, but this may be associated with greater muscle damage and a longer operative time. Case series and comparative studies should be encouraged to confirm the safety and utility of this technique.

Cost and Effectiveness of Percutaneous Endoscopic Interlaminar Discectomy versus Microscope-Assisted Tubular Discectomy for L5-S1 Lumbar Disc Herniation

OBJECTIVE

To assess the cost and effectiveness of percutaneous endoscopic interlaminar discectomy (PEID) and microscope-assisted tubular discectomy (MATD) for patients with L5/S1 lumbar disc herniation (LDH).

METHODS

The medical and financial records of patients diagnosed with L5/S1 LDH and who underwent either PEID or MATD from April 2021 to April 2022 were retrospectively collected. Demographic and baseline information, perioperative observational index, clinical outcomes, and inpatient costs were analyzed.

RESULTS

Sixty patients were included, with 30 patients in the PEID group and 30 patients in the MATD group. No significant difference was found in demographic and baseline information between the 2 groups (P > 0.05). The PEID group showed significantly shorter incision length, less intraoperative blood loss, shorter hospital stays, and higher intraoperative fluoroscopy frequency compared with the MATD group (P < 0.05). There were no significant differences in visual analog scale back/leg score, Oswestry Disability Index, and 36-Item Short-Form Survey score between PEID and MATD groups before the surgery and at any follow-up time points (P > 0.05). The total cost, surgery cost, and surgical instruments/materials cost were significantly higher in the PEID group compared with the MATD group (P < 0.05). In contrast, the drug and nursing costs were significantly higher in the MATD group than in the PEID group (P < 0.05).

CONCLUSIONS

PEID and MATD provide equivalent clinical efficacy and safety in treating LDH at L5/S1 segment within a 1-year follow-up. However, PEID is less invasive and MATD is less costly. No one surgical technique is superior in all aspects and patients should make decisions according to their top concern.

Management of Lumbar Disc Herniation: A Systematic Review

A herniated disc in the spine is a condition during which a nucleus pulposus is displaced from intervertebral space. It is a common cause of back pain. The patients who experience pain related to a herniated disc often remember an inciting event that caused their pain. This activity reviews the evaluation and management of lumbar disc herniation and discusses the role of the healthcare team in evaluating and improving care for patients with this condition. Data sources were PubMed/Medline and Embase. Our review investigated English-language articles (from 2010 to 2023) according to the PRISMA guidelines. Overall, there were seven articles. Surveys and analyses of national databases were the most widely used methods (n=7). The search identified 777 studies; 7 were eligible for inclusion in the analysis. Further understanding of spinal disc herniation and treatment protocols may help improve evaluation and management in the future. Our research covered a range of management options. Disc herniation is a frequent problem for internists, emergency department doctors, nurse practitioners, and primary care physicians. To manage efficiently, an interprofessional team is needed. The first course of treatment is conservative, with paracetamol and anti-inflammatories being frequently used to relieve pain. A chemist must supervise the use of opioid analgesics in certain situations. Although surgery is sometimes the final option, patients frequently have neurological damage and lingering discomfort. In circumstances where physical treatment is not working, MRI interpretation becomes necessary. Primary care physicians or mental health professionals should handle back pain as it is frequently linked to mental health issues. Results can be enhanced by regular exercise and preserving a healthy body weight.

Complications of Cervical Endoscopic Spinal Surgery: A Systematic Review and Narrative Analysis

BACKGROUND

There are no systematic evidence-based medical data on the complications of endoscopic cervical spinal surgery. This narrative analysis compiled data from various studies that examined endoscopic complications, such as cervical disc herniation and foraminal stenosis. This study aimed to investigate the efficacy and safety of endoscopic surgery in cervical radiculopathy.

METHODS

We searched the PubMed/MEDLINE databases to identify articles on endoscopic spinal surgery, and keywords were set as "endoscopic cervical spinal surgery", "endoscopic cervical discectomy", "endoscopic cervical foraminotomy", and "percutaneous endoscopic cervical discectomy". We analyzed the evidence level and classified the prescribed complications according to the literature. Endoscopic cervical surgery was divided into three categories: full endoscopic anterior, endoscopic posterior, and unilateral biportal approaches. We excluded duplicate publications, studies without full text, studies without complications or incomplete information, and studies that did not provide the necessary data for extraction, animal experiments, or reviews.

RESULTS

Difficulties in swallowing, hematoma, and hoarseness are common complications associated with the anterior cervical approach. In contrast, complications of the posterior approach include nerve root injury, hematoma, and dysesthesia. However, endoscopic cervical spinal surgery, including the full endoscopic anterior, posterior, and unilateral biportal approaches, is a safe and effective treatment for cervical radiculopathy.

CONCLUSIONS

Complications of full endoscopic cervical spinal surgery differ significantly depending on the anterior and posterior approaches. In the anterior approach, swallowing difficulty, recurrent disc, hematoma, and dysphonia are the common complications. In contrast, transient dysesthesia, dural tears, upper limb motor deficits, and persistent arm pain are commonly reported with the posterior approach.

Lumbar Endoscopic Unilateral Laminotomy With Bilateral Decompression Surgery in Severe Lumbar Stenosis Under Electrophysiological Monitoring-Focused on Full-Visualized Trephine/Osteotome

OBJECTIVE

Although endoscopic drill has the advantages in manipulation and hemostasis, whose low efficiency and blurred vision reduce the efficacy of lumbar endoscopic unilateral laminotomy with bilateral decompression (LE-ULBD). The present study was designed to evaluate the safety and efficacy of full-visualized trephine/osteotome in the LE-ULBD surgery for severe lumbar stenosis.

METHODS

Fifty-seven severe lumbar stenosis patients who underwent LE-ULBD between January 2020 to January 2023 were enrolled, who were divided into drill and visualized trephine groups. The medical records including demographics, operative duration, intraoperative electrophysiological findings, postoperative hospital stay or hospital stay, postoperative outcomes and complications were retrospectively reviewed and analyzed.

RESULTS

A total of 57 patients included 15 in drill and 42 in trephine group were enrolled in the study. There was significant difference in the pre- and postoperative visual analogue scale and Oswestry Disability Index scores in both groups (p < 0.05). The mean operative duration in the trephine group (101.05 ± 12.18 minutes) was shorter than that in the drill group (134.67 ± 9.68 minutes) (p < 0.05). There was no statistical difference between the 2 groups in electrophysiological monitoring, posthospital stays, postoperative outcomes and complications. Abnormal free-electromyography (EMG) were recorded in 2 (13.3%) and 5 patients (11.9%) in the drill and trephine group. Intraoperative somatosensory evoked potential changes occurred in 3 (20%) and 3 patients (7.1%) in the drill and trephine group and all patients recovered immediately when surgery ended. No serious complications and recurrence occurred in all the patients.

CONCLUSION

Full-visualized trephine/osteotome has been approved to be convenient, safe and efficient in our study, which combined with translaminar inside-out technique and EMG monitoring especially free-EMG may offer a new choice in LE-ULBD surgery for lumbar stenosis patients.

Risk Factors of Restenosis After Full Endoscopic Foraminotomy for Lumbar Foraminal Stenosis: Case-Control Study

OBJECTIVE

To investigate risk factors associated with postoperative restenosis after full endoscopic lumbar foraminotomy (FELF) in patients with lumbar foraminal stenosis (LFS).

METHODS

A single-center, retrospective case-control study was conducted on patients diagnosed with foraminal stenosis who underwent FELF between August 2019 and April 2022. The study included 56 patients, comprising 18 cases and 38 controls. Clinical data, radiologic assessments, and surgical types were compared between the groups. The cutoff values of radiologic parameters that differentiate the 2 groups were investigated.

RESULTS

No significant difference in age, sex distribution, or presence of adjacent segment disease or grade I spondylolisthesis was observed between the groups. Cases had a higher degree of disc wedging angle (DWA) (3.0° ± 1.1° vs. 0.5° ± 1.4°, p < 0.001), larger coronal Cobb angle (CCA) (8.8° ± 5.1° vs. 4.7° ± 2.5°, p = 0.004), and smaller segmental lumbar lordosis (SLL) than controls (11.0 ± 7.4 vs. 18.0 ± 5.4, p = 0.001). Optimal cutoff values for DWA, CCA, and SLL were estimated as 1.8°, 7.9°, and 17.1°, respectively. A significant difference in surgical types was observed between cases and controls (p = 0.004), with the case group having a higher distribution of patients undergoing discectomy in addition to TELF.

CONCLUSION

The study identified potential risk factors for restenosis after FELF in patients with LFS, including higher DWA, larger CCA, smaller SLL angle. We believe that discectomy should be perform with caution during FELF, as it can lead to subsequent restenosis.