Minimally Invasive Spine Surgery Research Articles

Overview of endoscopic spine surgery and learning curve

Spine surgery has witnessed significant advancements in endoscopic techniques over the past several decades. Compared to open approaches, endoscopic spine surgery allows for minimal tissue dissection, blood loss, and hospital stay, while optimizing early functional recovery. Recent improvements in instrumentation have enabled endoscopic techniques to address a larger range of degenerative pathology. However, regulatory barriers and specialized training are thought to underlie the purportedly steep learning curve, which hinders the widespread implementation of endoscopy in clinical practice. This review aims to provide an overview of endoscopic spine surgery and discuss its learning curve relative to other minimally invasive techniques.

Lumbar foraminal pathology: Biportal endoscopic spine surgical approaches

Spinal endoscopic approaches, full-endoscopic or biportal, allow for access to various lumbar foraminal pathologies while preserving the integrity of back muscles and facet joints. These minimal invasive procedures can eliminate the need for wide decompressions potentially decreasing the need for instrumented fusion. Early symptomatic recurrence most often arises due to inadequate decompression. Understanding the intricacies of foraminal pathology rather than assuming continued post-surgical pain is a result of spinal instability can change the paradigm of endoscopic spine surgery from endoscopic assisted fusion to true minimally invasive surgery. Surgeons should think whether early revision of spinal decompression could arise from insufficient foraminal decompression. This paper aims to elucidate the reader on foraminal pathoanatomy allowing the surgeon to understand when sufficient decompression is achieved and inform the surgeon on the technical aspects of surgery to minimize iatrogenic instability and incidental complications.

A narrative review of current and future of Unilateral Biportal Endoscopic (UBE) transforaminal lumbar interbody fusion

With the ongoing development of Unilateral Biportal Endoscopic (UBE) spine surgery, it has become standard of care at many centers across the globe for lumbar decompressions and discectomies due to minimal muscle damage, minimal postoperative back pain and early recovery. In UBE, the separation of viewing portal and working portal allows greater freedom of movement for the surgical instruments as the camera and instruments move independently providing unrestricted vision. Moreover, the continuous irrigation fluid pressure decreases bleeding and helps to irrigate out the bone debris. Hence, UBE spine surgery has become quite popular and has expanded its indications to lumbar spinal fusion. The adoption of UBE for conventional spine surgeons into their routine practice is relatively easier than uniportal endoscopy because of use of standard arthroscopic lenses, familiar view of anatomy, and use of conventional open spinal instruments. In this article, we review the current literature and discuss the indications, contraindications, clinical outcomes, complications and compare it with existing minimally invasive transforaminal lumbar interbody fusion.

Global Trends and Hotspots of Minimally Invasive Surgery in Lumbar Spinal Stenosis: A Bibliometric Analysis.

The popularity of minimally invasive surgery for lumbar spinal stenosis (LSS) has been steadily increasing worldwide. This study aims to conduct a comprehensive bibliometric analysis to identify global trends and hotspots in the research related to this surgical approach. Select articles related to the field that were retrieved from the Web of Science Core Collection (WoSCC) between January 1, 1993 and December 31, 2022. Visualization of networks and in-depth bibliometric analyses, including the number of publications, countries/regions, institutions, journals, authors, keywords, and references, were conducted using VOSviewer and CiteSpace software. A total of 1197 papers were identified over a three-decade period, with the highest production year being 2022, which saw 171 papers published. The most prolific countries/regions were the United States (279) and Harvard Medical School (59). Among journals, Spine (3289 citations) was the most cited, while World Neurosurgery (98 publications) had the highest number of publications. Lewandrowski, Kai-Uwe (29 publications) wrote the most articles, and Ahn, Y (239 citations) ranked first among cited authors. The most frequently used keyword was "discectomy", but recent years have shown a strong emergence of keywords such as "microendoscopic decompressive laminotomy", "foraminotomy" and "classification". The United States and China have emerged as leaders in the field of minimally invasive surgery for LSS. Endoscopic spinal surgery is recognized as a critical approach, with ongoing research focused on indications, potential complications, minimally invasive anatomical approaches, and outcomes. Furthermore, there is a strong emphasis on optimizing the surgical process, which has become a trending and hot spot in current research. The improvement of surgical techniques is at the forefront of advancements in this field.

Radiological subsequence after spinal endoscopic surgery alone to treat infectious spondylodiscitis: A retrospective mid-term follow-up

Radiological subsequence after spinal endoscopic surgery alone to treat infectious spondylodiscitis: A retrospective mid-term follow-up

ПРЕИМУЩЕСТВА СТРАТЕГИИ МАЛОИНВАЗИВНОЙ ТОРАКОЭНДОСКОПИЧЕСКОЙ ХИРУРГИИ ПРИ ОПЕРАТИВНЫХ ВМЕШАТЕЛЬСТВАХ НА ГРУДНОМ ОТДЕЛЕ ПОЗВОНОЧНИКА

The technology of video-assisted minimally invasive interventions on the thoracic spine is a promising direction in surgical endoscopy. Thoracic endoscopic spine surgery is effective for the diagnosis and treatment of various pathologies (tumors, inflammation, deformities, degenerative-dystrophic lesions, injuries). The advantages of thoracic endoscopic interventions are – trauma/injury reduction, reduced blood loss, full visualization of the operation area, the ability to control the allocation of surgical instruments, early activation and rehabilitation of patients as a result of minimally invasive technology, reduced hospital stay and treatment costs. Video-assisted minimally invasive interventions on the thoracic spine are a promising area of surgical endoscopy. The use of thoracoscopic technology allows us to move to a qualitatively new level of surgical interventions from anterior surgical approaches for various pathologies of the thoracic spine (tumors, deformities, degenerative-dystrophic lesions, injuries, inflammatory processes).

Validation of a modular training model for biportal endoscopic spine surgery

Validation of a modular training model for biportal endoscopic spine surgery

Effect of saline irrigation temperature differences on postoperative acute pain and hypothermia during biportal endoscopic spine surgery (BESS)

Effect of saline irrigation temperature differences on postoperative acute pain and hypothermia during biportal endoscopic spine surgery (BESS)

Ultrasound Robotic System to Multi-Approach Puncture for Endoscopic Spinal Surgery

Ultrasound Robotic System to Multi-Approach Puncture for Endoscopic Spinal Surgery

Prevalence and Techniques of endoscopic Spinal Surgery among accredited Training Centers in Switzerland

Prevalence and Techniques of endoscopic Spinal Surgery among accredited Training Centers in Switzerland

Australian Spine Surgeon's Perspectives on Endoscopic Spine Surgery: An In-depth Analysis.

Endoscopic spine surgery (ESS) is a minimally invasive approach with reduced tissue trauma, shorter hospital stays, and faster recovery times. It employs advanced endoscopic instruments and imaging technologies to address a wide range of spinal pathologies with minimal disruption to surrounding tissues. As ESS continues to evolve, this article aims to gather insights into the opinions and perspectives of the key stakeholders involved, and highlight strategies to improve implementation. A cross-sectional survey was distributed to collect data on Australian spine surgeons' perspectives of ESS. The survey questionnaire was distributed electronically to a diverse group of spine surgeons who are members of the Spine Society of Australia. Of responders, 46.8% were already integrating ESS into practice, or had the sufficient training to commence ESS. A further 29.8% were contemplating introduction of ESS techniques, while just under one quarter of respondents (23.4%) were not interested in implementing minimally invasive techniques. Primary motivators for implementation included skill development and improved patient outcomes. Primary barriers included lack of training opportunities, length of time to develop competency and lack of current supporting evidence. The study contributes to the existing body of knowledge on ESS by providing a comprehensive analysis of surgeon opinions and experiences. The results highlight the growing interest in endoscopic techniques, while recognizing the challenges that need to be addressed to make this more widely utilised and available. The findings can guide future research, training programs, clinical practice and ultimately improve health and financial outcomes to patients and the wider health system.

Screw Insertional Torque Measurement in Spine Surgery: Correlation With Bone Mineral Density and Hounsfield Unit.

Achieving successful fusion during spine surgery is dependent on rigid pedicle screw fixation. To assess fixation strength, the insertional torque can be measured during intraoperative screw fixation. This study aimed to explore the technical feasibility of measuring the insertional torque of a pedicle screw, while investigating its relationship with bone density. Thoraco-lumbar screw fixation fusion surgery was performed on 53 patients (mean age, 65.5 ± 9.8 years). The insertional torque of 284 screws was measured at the point passing through the pedicle using a calibrated torque wrench, with a specially designed connector to the spine screw system. The Hounsfield units (HU) value was determined by assessing the trabecular portion of the index vertebral body on sagittal computed tomography images. We analyzed the relationship between the measured insertional torque and the following bone strength parameters: bone mineral density (BMD) and HU of the vertebral body. The mean insertion torque was 105.55 ± 58.08 N∙cm and T-score value (BMD) was -1.14 ± 1.49. Mean HU value was 136.37 ± 57.59. Screw insertion torque was positively correlated with BMD and HU in whole patients. However, in cases of osteopenia, all variables showed very weak correlations with insertional torque. In patients with osteoporosis, there was no statistically significant correlation between BMD and torque strength; HU showed a significant correlation. The insertional torque of screw fixation significantly correlated with bone density (BMD and HU). HU measurements showed greater clinical significance than did BMD values in patients with osteoporosis.

The Endoscopic Lumbar Interbody Fusion: A Narrative Review, and Future Perspective.

Lumbar interbody fusion stands as a preferred surgical solution for degenerative lumbar spine diseases. The procedure primarily aims to establish lumbar segment stability, directly addressing patient symptoms associated with spinal complications. Traditional open surgery, though effective, is linked with notable morbidities and extended recovery time. To mitigate these concerns, minimally invasive surgery (MIS) has garnered significant popularity, presenting an appealing alternative with numerous benefits such as reduced soft tissue trauma, decreased blood loss, and expedited recovery. Among MIS procedures, full endoscopic spinal surgery, characterized by its minimal invasiveness, holds the potential to further minimize morbidities while enhancing surgical outcomes. Endoscopic lumbar interbody fusion, a novel procedure within this paradigm, has gained attention for offering advantages comparable to those of minimally invasive transforaminal lumbar interbody fusion. However, the safety, efficacy, and associated surgical techniques and instrument design of this method continue to be subjects of ongoing debate. This paper critically reviews current evidence on the safety, efficacy, and advantages of endoscopic lumbar spinal interbody fusion, examining whether it could indeed supersede existing mainstream techniques.

Monitored Anesthesia Care in Minimally Invasive Spine Surgery-A Retrospective Case Series Study.

Background and Objectives: Minimally invasive spine surgery (MISS) under monitored anesthesia care (MAC) has emerged as a treatment modality for spinal radiculopathy. It is essential to secure the airway and guarantee spontaneous respiration without endotracheal intubation during MISS in a prone position. Materials and Methods: To evaluate the feasibility and safety of MAC with dexmedetomidine during MISS, we retrospectively reviewed clinical cases. A retrospective review of medical records was conducted between September 2015 and June 2016. A total of 17 patients undergoing MISS were included. Vital signs were analyzed every 15 min. The depth of sedation was assessed using the bispectral index (BIS) and the frequency of rescue sedatives. Adverse events during anesthesia, including bradycardia, hypotension, respiratory depression, postoperative nausea, and vomiting, were evaluated. Results: All cases were completed without the occurrence of airway-related complications. None of the patients needed conversion to general anesthesia. The median maintenance dosage of dexmedetomidine for adequate sedation was 0.40 (IQR 0.40-0.60) mcg/kg/hr with a median loading dose of 0.70 (IQR 0.67-0.82) mcg/kg. The mean BIS during the main procedure was 76.46 ± 10.75. Rescue sedatives were administered in four cases (23.6%) with a mean of 1.5 mg intravenous midazolam. After dexmedetomidine administration, hypotension and bradycardia developed in six (35.3%) and three (17.6%) of the seventeen patients, respectively. Conclusions: MAC using dexmedetomidine is a feasible anesthetic method for MISS in a prone position. Hypotension and bradycardia should be monitored carefully during dexmedetomidine administration.

Treatment Concept and Technical Considerations of Biportal Endoscopic Spine Surgery for Lumbar Spinal Stenosis.

Decompression is a major component of surgical procedures for degenerative lumbar spinal stenosis (LSS). In addition to sufficient decompression to guarantee the relief of neurological pain, compensating surgical instability after wider laminectomy and foraminotomy and instrumentation with caging and fusion with grafting are performed to secure or restore the foraminal dimension and correct coronal/sagittal imbalance for longer survival of the adjacent segment. Endoscopic spinal surgery (ESS) has been developed under the flag of successful decompression while preserving structural integrity as much as possible with the help of magnification and illumination. ESS provides a technical possibility and feasibility for solving LSS by decompression alone. Recently, many endoscopic trials have been conducted to overcome conventional surgical treatment that requires wider dissection, escape inevitable complications from surgical damage, and compensate for the fusion technique. However, biportal ESS has some technical limitations, including clinical difficulties in accessibility for more moderate to severe stenosis and challenges for complicated conditions with segmental ventral slip, isthmic defect, stenosis combined with foraminal stenosis or foraminal disk rupture, or degenerative segmental scoliosis with disk height collapsing and endplate fatigue fracture. Because decompression alone is a skill for eliminating pathologies, there is no function of preserving degenerative structure or stopping the recurrence of disk degeneration or subsidence. This review of clinical reports investigated the possibility of biportal ESS for treating degenerative lumbar disorders by sufficient decompression and adequate elimination of various pathologies and decreasing technical complications. The results of this study may help develop better innovative spinal surgical techniques in the near future.

Finite element mechanical analysis of ipsilateral approach and contralateral approach in unilateral bilateral endoscopic spine surgery

BackgroundUnilateral bilateral endoscopic spine surgery (UBE) is often performed to treat lumbar spinal stenosis and disc herniation. It has become a prominent method in endoscopic spine surgery because of its very low learning curve and broader operative field of vision. Currently, the ipsilateral approach and contralateral approach have been established for disc herniation in the foraminal area, intervertebral foramen region, or pedicle region. The contralateral method offers many benefits over the ipsilateral approach, including less bone labour during microsurgical decompression and the preservation of facet joints. However, because it uses the interlaminar window approach, it inevitably involves osteotomy of the patient’s superior and inferior articular processes, which may result in corresponding deterioration in the spine’s biomechanical stability and subsequent adjacent facet joint diseases caused by facet joint degeneration postoperatively.ObjectiveAs a result, the purpose of this work is to use a finite element model to evaluate how the ipsilateral approach and contralateral approach in unilateral bilateral endoscopic spine surgery affect spinal stability while treating identical intervertebral disc herniation.Study designIn this study, a three-dimensional lumbar-sacral spine model was built and verified. Osteotomies were conducted for armpit-type lumbar disc herniation (LDH), periradicular-type LDH, and shoulder-type LDH. Postoperative lumbar spine models of the ipsilateral approach and contralateral approach in unilateral bilateral endoscopic spine surgery were developed. The von Mises stress on the endplate, shear force on the annulus fibrosus, pressure inside the intervertebral disc, and range of motion (ROM) of the L3 segment were all determined. The results of our well-validated model showed that osteotomy done in the ipsilateral approach deteriorated most biomechanical metrics.ResultsIn the majority of loading conditions, the contralateral approach caused the intervertebral disc’s biomechanical properties to increase, and the ipsilateral approach caused the intervertebral disc’s biomechanical properties to increase sharply more than the contralateral approach.ConclusionThe contralateral approach, which is now extensively employed in unilateral bilateral endoscopic spine surgery, may be regarded as an ideal surgical alternative for treating lumbar disc herniation without producing iatrogenic instability. This approach has a low facet joint reduction rate, minimum soft tissue injury, and precisely identifies the midline of the central spinal canal during the retraction of the thecal sac and nerve roots.

Letter to the Editor Regarding “Full Endoscopic Spine Surgery with Image-Guided Navigation System as ‘Hybrid Endoscopic Spine Surgery’”

Letter to the Editor Regarding “Full Endoscopic Spine Surgery with Image-Guided Navigation System as ‘Hybrid Endoscopic Spine Surgery’”

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

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. 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. 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. 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.

Assessing the impact of obesity on full endoscopic spine surgery: surgical site infections, surgery durations, early complications, and short-term functional outcomes.

An increasing number of obese patients undergoing elective spine surgery has been reported. Obesity has been associated with a substantially higher number of surgical site infections and a longer surgery duration. However, there is a lack of research investigating the intersection of obesity and full endoscopic spine surgery (FESS) in terms of functional outcomes and complications. The aim of this study was to evaluate wound site infections and functional outcomes following FESS in obese patients. Patients undergoing lumbar FESS at the participating institutions from March 2020 to March 2023 for degenerative pathologies were included in the analysis. Patients were divided into obese (BMI > 30 kg/m2) and nonobese (BMI 18-30 kg/m2) groups. Data were collected prospectively using an approved smartphone application for 3 months postsurgery. Parameters included demographics, surgical details, a virtual wound checkup, the visual analog scale for back and leg pain, and the Oswestry Disability Index (ODI) as a functional outcome measure. A total of 118 patients were included in the analysis, with 53 patients in the obese group and 65 in the nonobese group. Group homogeneity was satisfactory regarding patient age (obese vs nonobese: 55.5 ± 14.7 years vs 59.1 ± 17.1 years, p = 0.25) and sex (p = 0.85). No surgical site infection requiring operative revision was reported for either group. No significant differences for blood loss per level (obese vs nonobese: 9.7 ± 16.8 ml vs 8.0 ± 13.3 ml, p = 0.49) or duration of surgery per level (obese vs nonobese: 91.2 ± 57.7 minutes vs 76.8 ± 39.2 minutes, p = 0.44) were reported between groups. Obese patients showed significantly faster improvement regarding ODI (-3.0 ± 9.8 vs 0.7 ± 11.3, p = 0.01) and leg pain (-4.4 ± 3.2 vs -2.9 ± 3.7, p = 0.03) 7 days postsurgery. This effect was no longer significant 90 days postsurgery for either ODI (obese vs nonobese: -11.4 ± 11.4 vs -9.1 ± 9.6, p = 0.24) or leg pain (obese vs nonobese: -4.3 ± 3.9 vs -3.5 ± 3.8, p = 0.28). The results highlight the effectiveness and safety of lumbar FESS in obese patients. Unlike with open spine surgery, obese patients did not experience significant increases in surgery time or postoperative complications. Interestingly, obese patients demonstrated faster early recovery, as indicated by significantly greater improvements in ODI and leg pain at 7 days after surgery. However, there was no difference in improvement between the groups at 90 days after surgery.

Minimally Invasive Surgery for Posterior Spinal Instrumentation and Fusion in Adolescent Idiopathic Scoliosis: Current Status and Future Application.

The posterior minimally invasive spine surgery (MISS) approach-or the paraspinal muscle approach-for posterior spinal fusion and segmental instrumentation in adolescent idiopathic scoliosis (AIS) was first reported in 2011. It is less invasive than the traditionally used open posterior midline approach, which is associated with significant morbidity, including denervation of the paraspinal muscles, significant blood loss, and a large midline skin incision. The literature suggests that the MISS approach, though technically challenging and with a longer operative time, provides similar levels of deformity correction, lower intraoperative blood loss, shorter hospital stays, better pain outcomes, and a faster return to sports than the open posterior midline approach. Correction maintenance and fusion rates also seem to be equivalent for both approaches. This narrative review presents the results of relevant publications reporting on spinal segmental instrumentation using pedicle screws and posterior spinal fusion as part of an MISS approach. It then compares them with the results of the traditional open posterior midline approach for treating AIS. It specifically examines perioperative morbidity and radiological and clinical outcomes with a minimal follow-up length of 2 years (range 2-9 years).