Feasibility of Using Intraoperative Neuromonitoring in the Prophylaxis of Dysesthesia in Transforaminal Endoscopic Discectomies of the Lumbar Spine

Biplane Ultrasound Versus Fluoroscopy for Guidance of Percutaneous Lumbar Intervertebral Foramen Insertion : A Randomized Controlled Clinical Trial

STUDY DESIGN

A randomized controlled study.

OBJECTIVE

The aim of this study was to develop a clinical process of biplane ultrasound (US) guided percutaneous lumbar intervertebral foramen insertion (PLIFI) and to verify that biplane US can improve accuracy and reduce number of fluoroscopies.

SUMMARY OF BACKGROUND DATA

PLIFI is crucial for drug injection and establishment of transforaminal surgical channel. The traditional fluoroscopy guidance involves radiation and requires practical experience.

METHODS

Patients with lumbar disc herniation scheduled for an epidural steroid injection or percutaneous endoscopic lumbar discectomy were randomized to the biplane US and fluoroscopy groups. The biplane US group was divided into training and proficiency stages using a learning curve fitted by cumulative sum analysis. All punctures were performed by a junior spine surgeon and a junior sonographer. The primary outcomes were the first success rate, number of punctures and radiographs, puncture time, and confidence score.

RESULTS

Sixty-eight patients (age 51.4±15.4 yr, 36 males) were divided into the biplane US and fluoroscopy groups. According to the 12th turning point of a learning curve, the biplane US group was divided into training and proficiency periods. The first-attempt success rate was achieved in 61% using biplane US at the proficiency period, compared with 32% using fluoroscopy [ P =0.033, RR: 1.634]. The number of radiographies [1 (IQR 1-2) vs . 2 (IQR 2-3), P =0.001] was significantly smaller, and puncture time [120 s (IQR 57-210) vs. 197 s (IQR 159-341), P =0.001] was significantly faster using biplane US at the proficiency period.

CONCLUSION

Biplane US provides an accurate, safe, and convenient approach for PLIFI. With further clinical practice, biplane US would be conducive to rapid skill acquisition for novices and has the potential to achieve a completely radiation-free puncture process.

Complications in Full-Endoscopic Posterior Cervical Surgery: A Review of the Literature and Preventive Strategies

Study DesignNarrative reviewObjectivesFull-endoscopic cervical spinal surgery via a posterior approach has gained popularity for its effectiveness in treating various cervical spine pathologies. However, this technique presents its own set of complications that need to be recognized and addressed. This review aims to comprehensively analyze the complications associated with full-endoscopic posterior cervical spine surgery and provide preventive strategies to minimize these risks and ensure successful surgical outcomes.MethodsA thorough literature search was conducted using public databases, including PubMed and SCOPUS, from January 2000 to June 2024. The review focused on analyzing complications related to full-endoscopic posterior cervical spine surgery and identifying preventive strategies using the keywords "Complication," "Endoscopic," "Full-endoscopic," "Endoscopy," "Uniportal," "Biportal," "Posterior," "Cervical," "Spine," "Surgery," "Foraminotomy," "Decompression," and "Discectomy".ResultsThe review identified a variety of complications associated with full-endoscopic posterior cervical spine surgery, including neurological, vascular, and structural issues. Despite the minimally invasive benefits of this approach, risks such as nerve root injury, dural tears, and epidural hematomas still exist. The study emphasizes preventive strategies like meticulous preoperative planning, refined surgical techniques, and cautious intraoperative management around neural structures to mitigate these risks.ConclusionsWhile full-endoscopic posterior cervical spine surgery provides significant advantages, such as reduced tissue disruption and quicker recovery, it also carries specific complications that must be carefully addressed and managed. Prevention is crucial for ensuring optimal outcomes. By understanding potential risks and implementing effective prevention strategies, surgeons can significantly reduce complications and enhance patient safety.

Magnetic Resonance Imaging Predictors of Surgical Difficulty in Transforaminal Endoscopic Lumbar Discectomy for Far-Lateral Disc Herniation Under Local Anesthesia

Background/Objectives: Transforaminal endoscopic lumbar discectomy (TELD) is a minimally invasive spinal surgery known for its effectiveness, lower complication rates, faster recovery, and ability to be performed under local anesthesia. However, foraminal narrowing or access pain during the transforaminal approach can delay or hinder surgery in patients with far-lateral lumbar disc herniation (LDH). The objectives of this study were to identify predictive factors from preoperative magnetic resonance imaging (MRI) findings and demographics and discuss the optimization of surgical strategies. Methods: This retrospective study included 75 patients with far-lateral LDH who underwent TELD. Preoperative demographics and MRI findings were analyzed. Surgical data, including operative time, length of hospital stay, and intraoperative pain, were recorded. Postoperative outcomes, including complications, revision surgeries, and global outcomes based on the modified Macnab criteria, were evaluated. Preoperative clinical and radiological factors affecting the operative data and results were analyzed. Results: A higher foraminal stenosis grade was significantly correlated with prolonged operative time (p < 0.01) and extended hospital stay (p < 0.01). Extraforaminal LDH was associated with more severe access pain (p < 0.01) owing to increased nerve root irritation. Access pain was significantly correlated with operative time (p < 0.01) and hospital stay (p < 0.01). Appropriate surgical techniques and intraoperative pain management can mitigate these challenges. Conclusions: Preoperative MRI findings, particularly the grade of foraminal narrowing and herniation zone, can predict surgical difficulty and outcomes in TELD for far-lateral LDH. These insights can guide tailored strategies to reduce access pain and improve procedural success under local anesthesia.

Augmenting Endoscopic Transforaminal Spinal Decompression Surgery (Full Endoscopic Spine Surgery) Using Stimulated Electromyography Neuromonitoring Dilators

BACKGROUND

Full endoscopic spine surgery via a transforaminal approach (FESS-TFA) offers a minimally invasive approach for spinal decompression. However, it carries a risk of nerve root irritation or injury. Existing intraoperative neuromonitoring primarily provides retrospective warnings of potential nerve disturbance.

OBJECTIVE

To introduce the use of stimulated electromyography neuromonitoring dilators in FESS-TFA for proactive nerve protection, enhanced localization, and potential reduction in radiation exposure.

METHODS

This technical note describes the first use of neuromonitoring dilators in FESS-TFA. A 6-mm dilator tipped with a stimulation electrode is introduced to provide real-time directional feedback regarding nerve proximity, allowing the surgeon to actively avoid accidental injury to the exiting nerve root. With the creation of a safe tract, subsequent introduction of working instruments would theoretically reduce the risk of neural injury.

RESULTS

The technique was successfully applied in a case of T11/T12 severe spinal stenosis, facilitating safe instrument passage and nerve localization. We describe the surgical technique and provide illustrative intraoperative details.

CONCLUSION

Neuromonitoring dilators represent a promising innovation in FESS-TFA with the potential to enhance patient safety and possibly streamline the procedure. Larger-scale studies are warranted to quantify the true impact of this technique on complication rates, operative time, and radiation exposure.

CLINICAL RELEVANCE

This technique highlights a significant advancement in reducing neural complications during minimally invasive spinal surgeries. By proactively preventing nerve irritation or injury and reducing radiation exposure, it contributes to optimizing surgical workflows and improving patient outcomes.

LEVEL OF EVIDENCE: 5

Next-Generation Neuromonitoring in Minimally Invasive Spine Surgery: Indications, Techniques, and Clinical Outcomes

Neuromonitoring in minimally invasive spine surgery (MISS) provides real-time feedback to surgeons and enhances surgical precision for improved patient safety. Since the 1970s, established techniques like somatosensory evoked potentials, motor evoked potentials, and electromyography have been integrated into spine surgeries, significantly reducing the risk of neurological complications. These neuromonitoring modalities have been crucial, particularly in complex procedures with limited direct visualization. Refinements in these techniques have led to greater confidence in nerve root safety, contributing to the success of MISS. Despite some debate regarding the routine use of neuromonitoring in noncomplex surgeries, its importance in complex cases is well-documented. Studies have demonstrated high sensitivity and specificity rates for these techniques, with multimodal approaches offering the best outcomes. Advancements in mechanomyography and its potential integration into neuromonitoring protocols highlight the continuous improvement in this field. This review explores the historical development, current techniques, clinical outcomes, and future directions of neuromonitoring in MISS. It emphasizes the critical role of these technologies in enhancing surgical outcomes and patient care. As MISS continues to evolve, adopting next-generation neuromonitoring systems, including artificial intelligence and machine learning, will play a pivotal role in advancing the efficacy and safety of spine surgeries.

Full-endoscopic lumbar spine surgery using working-channel endoscopes: technical tips for practical effectiveness

INTRODUCTION

Full-endoscopic spine surgery (FESS) has emerged as an effective and minimally invasive option for the surgical treatment of degenerative lumbar spine disease. FESS can be characterized as endoscopic spine surgery conducted via the percutaneous uniportal approach using working-channel endoscopes under continuous saline irrigation. Despite available evidence, the clinical application of this endoscopic procedure may require more work for standard spine surgeons. Therefore, this review aims to provide comprehensive technical tips to ensure the practical effectiveness of FESS.

AREA COVERED

FESS of the thoracolumbar spine can be performed through the transforaminal and interlaminar approaches according to direction and passing window. Published literature on technical tips and learning were reviewed narratively, after which practical technical pearls were demonstrated specific to the properties of working-channel endoscopes.

EXPERT OPINION

Currently, FESS remains a reliable option for achieving successful surgical outcomes in cases of lumbar disk herniation and spinal stenosis, with few complications and rapid recovery. A comprehensive understanding of the core features of working-channel endoscopes is crucial for expediting the learning process. Importantly, the development of specific instruments, surgical approaches, and optics is a continuous process that is necessary for establishing FESS as the standard technique for degenerative lumbar spine disease.

Complications in Minimally Invasive Spine Surgery in the Last 10 Years: A Narrative Review

OBJECTIVE

Minimally invasive spine surgery (MISS) employs small incisions and advanced techniques to minimize tissue damage while achieving similar outcomes to open surgery. MISS offers benefits such as reduced blood loss, shorter hospital stays, and lower costs. This review analyzes complications associated with MISS over the last 10 years, highlighting common issues and the impact of technological advancements.

METHODS

A systematic review following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines was conducted using PubMed, MEDLINE, Embase via OVID, and Cochrane databases, covering publications from January 2013 to March 2024. Keywords related to MISS and complications were used. Studies on adult patients undergoing MISS with tubular, uniportal, or biportal endoscopy, reporting intraoperative or postoperative complications, were included. Non-English publications, abstracts, and small case series were excluded. Data on MISS approach, patient demographics, and complications were extracted and reviewed by 2 independent researchers.

RESULTS

The search identified 880 studies, with 137 included after screening and exclusions. Key complications in cervical MISS were hematomas, transient nerve root palsy, and dural tears. In thoracic MISS, complications included cerebrospinal fluid leaks and durotomy. In lumbar MISS, common complications were incidental dural injuries, postoperative neuropathic conditions, and disc herniation recurrences. Complications varied by surgical approach.

CONCLUSION

MISS offers reduced anatomical disruption compared to open surgery, potentially decreasing nerve injury risk. However, complications such as nerve injuries, durotomies, and hardware misplacement still occur. Intraoperative neuromonitoring and advanced technologies like navigation can help mitigate these risks. Despite variability in complication rates, MISS remains a safe, effective alternative with ongoing advancements enhancing its outcomes.

Intra-operative Neurophysiological Monitoring in Patients Undergoing Posterior Spinal Correction Surgery with Pre-operative Neurological Deficit: Its Feasibility and High-risk Factors for Failed Monitoring

OBJECTIVE

Considering spinal deformity patients with pre-operative neurological deficit were associated with more intra-operative iatrogenic neurological complications than those without, intra-operative neurophysiological monitoring (IONM) has been used for detecting possible iatrogenic injury timely. However, the IONM waveforms are often unreliable. To analyze the performance of intra-operative neurophysiological monitoring (IONM) including somatosensory evoked potentials (SEP) and motor evoked potentials (MEP) in patients with pre-operative neurological deficit undergoing posterior spinal correction surgery, and to identify the high-risk factors for failed IONM.

METHODS

Patients with pre-operative neurological deficit undergoing posterior spinal correction surgery between October 2017 and January 2022 were retrospectively reviewed. The presence or absence of SEP and MEP of target muscles were separately recorded. The P37/N50 latency and amplitude of SEP, and the MEP amplitude were measured. Any IONM alerts were also recorded. The IONM performance was compared among patients with different etiologies, levels responsible for neurological deficit, and strength of IONM-target muscles. Patients' demographics were analyzed using the descriptive statistics and were presented with mean ± standard deviation. Comparison analysis was performed using χ2 -test and statistically significant difference was defined as p < 0.05.

RESULTS

A total of 270 patients (147 males, 123 females) with an average age of 48.4 ± 36.7 years were involved. The SEP records were available in 371 (68.7%) lower extremities while MEP records were available in 418 (77.4%). SEP alerts were reported in 31 lower extremities and MEP alerts in 22, and new neurological deficit at post-operation was observed in 11. The etiologies of neuromuscular and syndromic indicated relatively lower success rates of IONM, which were 44.1% and 40.5% for SEP, and 58.8% and 59.5% for MEP (p < 0.001). In addition, patients with pre-operative neurological deficit caused by cervical spine and muscle strength lower than grade 4 suffered from higher risk of failed IONM waveforms (p < 0.001).

CONCLUSION

Patients with pre-operative neurological deficit suffered from a higher incidence of failed IONM results. The high-risk for failed IONM waveforms included the neuromuscular and syndromic etiologies, neurological deficit caused by cervical spine, muscle strength lower than grade 4 in patients with pre-operative neurological deficit undergoing posterior spinal correction surgery.

Difficulties, Challenges, and the Learning Curve of Avoiding Complications in Lumbar Endoscopic Spine Surgery

Spinal endoscopy has the stigma of being reserved for only a few surgeons who can figure out how to master the steep learning curve and develop clinical practice settings where endoscopic spine surgery can thrive. In essence, endoscopic treatment of herniated discs specifically and nerve root compression in the lumbar spine in general amounts to replacing traditional open spine surgery protocols with spinal endoscopic surgery techniques. In doing so, the endoscopic spine surgeon must be confident that the degenerative spine's common painful problems can be handled with endoscopic spinal surgery techniques with at least comparable clinical results and complication rates. In this review article, the authors illustrate the difficulties and challenges of the endoscopic lumbar decompression procedure. In addition, they shed light on how to master the learning curve by systematically looking at all sides of the problem, ranging from the ergonomic aspects of the endoscopic platform and its instruments, surgical access planning, challenging clinical scenarios, complications, and sequelae, as well as the training gaps after postgraduate residency and fellowship programs.

Dural Tears During Lumbar Spinal Endoscopy: Surgeon Skill, Training, Incidence, Risk Factors, and Management

BACKGROUND

Incidental dural tears during lumbar endoscopy can be challenging to manage. There is limited literature on their appropriate management, risk factors, and the clinical consequences of this typically uncommon complication.

MATERIALS AND METHODS

To improve the statistical power of studying durotomy with lumbar endoscopy, we performed a retrospective survey study among endoscopic spine surgeons by email and chat groups on social media networks, including WhatsApp and WeChat. Descriptive and correlative statistics were done on the surgeons' recorded responses to multiple-choice questions. Surgeons were asked about their clinical experience with spinal endoscopy, training background, the types of lumbar endoscopic decompression they perform by approach, the decompression instruments they use, and incidental durotomy incidence with routine lumbar endoscopy.

RESULTS

There were 689 dural tears in 64 470 lumbar endoscopies, resulting in an incidental durotomy incidence of 1.07%. Seventy percent of the durotomies were reported by 20.4% of the surgeons. Eliminating these 19 outlier surgeons yielded an adjusted durotomy rate of 0.32. Endoscopic stenosis decompression (54.8%; P < .0001), rather than endoscopic discectomy (44.1%; 41/93), was significantly more associated with durotomy. Medium-sized dural tears (1-10 mm) were the most common (52.2%; 48/93). Small pinhole durotomies (less than 1 mm) were the second most common type (46.7%; 43/93). Rootlet herniations were seen by 46.2% (43/93) of responding surgeons. The posterior dural sac injury during the interlaminar approach (57%; 53/93) occurred more frequently than traversing nerve-root injuries (31.2%) or anterior dural sac (23.7%; 22/93). Exiting nerve-root injuries (10.8%;10/93) were less common. Over half of surgeons did not attempt any repair or closure (52.2%; 47/90). Forty percent (36/90) used sealants. Only 7.8% (7/90) of surgeons attempted an endoscopic repair or sutures (11.1%; 10/90). DuralSeal was the most commonly used brand of commercially available sealant used (42.7%; 35/82). However, other sealants such as Tisseal (15.9%; 13/82), Evicel (2.4%2/82), and additional no-brand sealants (38; 32/82) were also used. Nearly half of the patients (48.3%; 43/89) were treated with 24-48 hours of bed rest. The majority of participating surgeons (64%; 57/89) reported that the long-term outcome was unaffected. Only 18% of surgeons reported having seen the development of a postoperative cerebrospinal fluid (CSF)-fistula (18%;16/89). However, the absolute incidence of CSF fistula was only 0.025% (16/64 470). Severe radiculopathy with dysesthesia; sensory loss; and motor weakness in association with an incidental durotomy were reported by 12.4% (11/89), 3.4% (3/89), and 2.2% (2/89) of surgeons, respectively.

CONCLUSIONS

The incidence of dural tears with lumbar endoscopy is about 1%. The incidence of durotomy is higher with the use of power drills and the interlaminar approach. Stenosis decompression that typically requires the more aggressive use of these power instruments has a slightly higher incidence of dural tears than does endoscopic decompression for a herniated disc. Most dural tears are small and can be successfully managed with mechanical compression with Gelfoam and sealants. Two-thirds of patients with incidental dural tears had an entirely uneventful postoperative course. The remaining one-third of patients may develop a persistent CSF leak, radiculopathy with dysesthesia, sensory loss, or motor function loss. Patients should be educated preoperatively and reassured.

LEVEL OF EVIDENCE

3.