Is minimally invasive surgery a game changer in spinal surgery?

Minimally invasive spine surgery (MISS) has revolutionized the treatment of spinal disorders over the past few decades. This review provides an in-depth analysis of MISS techniques, technologies, outcomes, and future directions. The evolution of MISS techniques-including tubular retractor systems, percutaneous pedicle screw fixation, minimally invasive transforaminal lumbar interbody fusion, lateral lumbar interbody fusion, and endoscopic spine surgery-has expanded the scope of treatable spinal pathologies while minimizing tissue trauma. Technological advancements such as intraoperative navigation, robotics, and augmented reality applications have enhanced precision and capabilities. Clinical evidence supports the efficacy and safety of MISS techniques for various spinal pathologies, demonstrating comparable or superior outcomes to traditional open approaches with reduced tissue trauma, blood loss, and hospital stays. Cost-effectiveness analyses also favor MISS over open techniques. Future directions in MISS include expanding indications, integrating artificial intelligence and machine learning, advancing tissue engineering and biologics, and refining robotic and augmented reality applications. As MISS continues to evolve, it is poised to play an increasingly important role in the treatment of spinal disorders, offering improved patient outcomes with reduced morbidity. However, ongoing rigorous evaluation of new techniques and technologies is crucial to balance potential benefits with associated risks and costs.

Navigated Exoscopic Transtubular Approach for Lumbar Decompression: Surgical Video

Tubular retractors in minimally invasive lumbar stenosis permit surgeons to achieve satisfactory neural decompression while minimizing the morbidity of the surgical access.1-3 Transtubular lumbar decompression requires intraoperative image guidance and microscopic magnification to achieve precise and reproductible surgical results. Use of 2-dimensional image guidance in transtubular lumbar decompression has a major limitation due to the lack of multiplanar orientation. Consequently, there is a risk of incomplete decompression and excessive bone removal resulting in iatrogenic instability. Furthermore, available microscopes have limited optics (short focal lengths) and unsatisfactory surgeon ergonomics. To overcome these limitations, the authors present a step-by-step video of the navigated exoscopic transtubular approach (NETA) for spinal canal decompression (Video 1). The patient suffers from bilateral L5 radiculopathy due to L4-L5 bilateral synovial cysts responsible for severe L4-L5 canal stenosis. During the entire surgical procedure, NETA implements the use of navigation based on intraoperative 3-dimensional (3D) fluoroscopic images for retractor placement, bone mapping, and neural decompression.4 NETA represents a modification of the "standard" MIS transtubular technique for bilateral lumbar decompression. NETA is based on the use of neuronavigation during each surgical step to guide the placement of tubular retractor. This tailors the bone resection to achieve adequate neural decompression while minimizing the risks of potential spine instability. After precise placement of the tubular retractor, bone removal and neural decompression are accomplished under robotic exoscope magnification with 4k 3D images. Using a 3D robotic exoscope (Modus V, Synaptive, Toronto, Canada) allows better tissue magnification and improves surgeon ergonomics during lumbar decompression through tubular retractors.5,6.

Commercial suture passer improves efficiency and ease of use versus conventional needle in minimally invasive thoracolumbar fascia closure: a cadaveric analysis

Background

Low-profile suture passers have been introduced to facilitate thoracolumbar fascia closure in minimally invasive spine (MIS) surgery. The purpose of this study was to evaluate the closure time of a modern suture passer to a conventional curved need for MIS fascia closure in a cadaveric model.

Methods

Six clinicians specializing in orthopedic spine surgery were recruited for the study and randomly assigned 1 cadaveric torso. Subcutaneous tissue was resected at L4-L5, replicating MIS surgery, followed by placement of a 60×18-mm or 100×18-mm tubular retractor for access. Clinicians were required to close the fascia with three unknotted, simple interrupted sutures using a swaged curved needle or suture passer (Spine Scorpion™, Arthrex, Inc., Naples, FL). The completion time was recorded, starting immediately before suturing and ending after the last pass. A time cutoff of 10 min was implemented in consideration of reasonable operating room time, and the number of achieved suture passes (of 6) were recorded. Clinicians were asked to qualitatively grade ease of use in relation to prior fascial closure experience per a 0-5 scale, where 0 is impossible and 5 is easiest.

Results

The mean change in fascial closure completion time (Δ) was significantly reduced with the Spine Scorpion compared to the curved needle with the 60×18-mm retractor (Δ=5.80 min; 95% CI, 2.92-8.67 min; p=.004) and 100 × 18-mm retractor (Δ=5.28 min; 95% CI, 2.76-7.80 min; p=.003). Full closure was achieved within the time limit for all trials of the Spine Scorpion, while the standard needle achieved full closure in 67% (4 of 6) and 50% (3 of 6) of trials with the 60 × 18-mm and 100×18-mm retractors, respectively. Median ease-of-use scores with the 60×18-mm and 100×18-mm retractors, respectively, were 4.5 (range, 4-5) and 4.5 (range, 3-5) for the Spine Scorpion, and both 1.0 (range, 1-2) for the curved needle.

Conclusion

Results from this laboratory investigation using a suture passer for thoracolumbar fascia closure show a significant reduction in closure time and completion of the procedure compared to a conventional curved needle.

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.

A novel endoscope-port unit for lumbar microendoscopic surgery: a single-center case series review

Minimally invasive spinal surgery has shown benefits not only from a clinical standpoint but also in some cost-effectiveness metrics. Microendoscopic procedures combine optical advantages of endoscopy with the preservation of bimanual surgical maneuvers that are not feasible with full percutaneous endoscopic procedures. TELIGEN is a new endoscopic platform designed to optimize these operations. Our aim was to present a retrospective review of surgical data from the first consecutive cases applying this device in our institution and describe some of its technical details. 25 patients have underwent procedures using this device at our institution to the date, with a mean follow-up of 341.7 ± 45.1 days. 17 decompression-only procedures, including microendoscopic discectomies (MED) and decompression of stenosis (MEDS), with or without foraminotomies (± MEF) and 8 microendoscopic transforaminal lumbar interbody fusions (ME-TLIF) were performed. Mean age and body mass index (BMI) were respectively 58.8 ± 17.4 years and 27.6 ± 5.3 kg/m2. Estimated blood loss (13 ± 4.8, 12.8 ± 6.98 and 76.3 ± 35.02 mL), postoperative length of hospital stay (11.2 ± 21.74, 22.1 ± 26.85 and 80.7 ± 44.60 h), operative time (130.3 ± 58.53, 121 ± 33.90 and 241.5 ± 45.27 min) and cumulative intraprocedural radiation dose (14.2 ± 6.36, 15.4 ± 12.17 and 72.8 ± 12.26 mGy) are reported in this paper for MED ± MEF, MEDS ± MEF and ME-TLIF, respectively. TELIGEN affords an expanded surgical field of view with unique engineered benefits that provide a promissing platform to enhance minimally invasive spine surgery.

Innovations in the Treatment of Spinal Cerebrospinal Fluid Leaks

Spontaneous spinal cerebrospinal fluid (CSF) leaks are uncommon but can be neurologically debilitating. When initial treatments fail, definitive repair or closure of the leak is indicated. Depending upon the type of leak present, innovative strategies for their treatment have been developed. Among them are open surgical techniques using a transdural approach for the closure of ventral CSF leaks, minimally invasive tubular techniques for the reduction and repair of lateral meningeal diverticula, and endovascular embolization of CSF-venous fistulas. Illustrative cases demonstrating the indications for and implementation of these techniques are provided.

Prospective Study of the Assessment of Anxiety Symptoms after Minimally Invasive Lumbar Decompression

Objective  To analyze associations between anxiety and postsurgical clinical outcomes in patients who underwent minimally invasive lumbar decompression surgery in addition to comparing symptoms of anxiety and depression before and after surgery. Methods  This prospective cohort study of patients who underwent minimally invasive lumbar decompression surgery. Clinical outcomes were measured before and 6 months after surgery using the Visual Analog Scale (VAS), Global Perceived Effect of Change (GPE), Hospital Anxiety and Depression Scale (HADS), and Oswestry Disability Index (ODI). Based on the presurgical anxiety score, patients were categorized into anxious and non-anxious patients, and the outcomes were compared. Results  The patients of both groups obtained similar results concerning the clinical outcomes evaluated. Preoperative HADS scores decreased significantly 6 months after surgery in both anxiety (8.70 ± 3.48 vs. 5.75 ± 3.91) and depression (6.95 ± 3.54 vs. 5.50 ± 2.99). The VAS scale for the back (-2.8 ± 3.64) and legs (-5.5 ± 3.5) showed a reduction in pain. Conclusion  Minimally invasive lumbar decompression surgery promoted clinical and functional improvement, not being affected by preoperative anxiety symptoms. Mental health indicators showed a significant reduction in symptoms 6 months after surgery.

Lumbar Tubular Decompression: Barriers and Limitations Hampering the Technique's Dissemination Across Latin America

OBJECTIVES

We sought to explore the barriers and limitations preventing the widespread use of tubular lumbar spine decompressions in Latin America.

METHODS

A cross-sectional study was performed using a survey designed specifically by the authors. This survey was mailed to all spine surgeons who are members of AO Spine Latin America. Eighty-seven surgeons spanning 15 Latin American countries answered the survey.

RESULTS

Thirty-one percent of participating surgeons claimed they needed to adapt their technique to perform minimally invasive tubular surgeries. Meanwhile, though 70.5% answered they do not consider tubular surgery expensive, 32.8% lacked access to standard equipment like a complete set of retractors or curved high-speed drill.

CONCLUSIONS

Several barriers limit the development of tubular spine surgery in Latin America. The most important discrepancies between surgeons' preferred equipment and their availability for such operations are high-speed drills, bayoneted instruments, and hemostatic agents.

Ten-step minimally invasive slalom unilateral laminotomy for bilateral decompression (sULBD) with navigation

BACKGROUND

Unilateral laminotomy for bilateral decompression (ULBD) is a MIS surgical technique that offers safe and effective decompression of lumbar spinal stenosis (LSS) with a long-term resolution of symptoms. Advantages over conventional open laminectomy include reduced expected blood loss, muscle damage, mechanical instability, and less postoperative pain. The slalom technique combined with navigation is used in multi-segmental LSS to improve the workflow and effectiveness of the procedure.

METHODS

We outline ten technical steps to achieve a slalom unilateral laminotomy for bilateral decompression (sULBD) with navigation. In a retrospective case series, we included patients with multi-segmental LSS operated in our institution using the sULBD between 2020 and 2022. The primary outcome was a reduction in pain measured by Visual Analogue Scale (VAS) for back pain and leg pain and Oswestry Disability Index (ODI).

RESULTS

In our case series (N = 7), all patients reported resolution of initial symptoms on an average follow-up of 20.71 ± 9 months. The average operative time and length of hospital stay were 196.14 min and 1.67 days, respectively. On average, VAS (back pain) was 4.71 pre-operatively and 1.50 on long-term follow-up of an average of 19.05 months. VAS (leg pain) decreased from 4.33 to 1.21. ODI was reported as 33% pre-operatively and 12% on long-term follow-up.

CONCLUSION

The sULBD with navigation is a safe and effective MIS surgical procedure and achieves the resolution of symptoms in patients presenting with multi-segmental LSS. Herein, we demonstrate the ten key steps required to perform the sULBD technique. Compared to the standard sULBD technique, the incorporation of navigation provides anatomic localization without exposure to radiation to staff for a higher safety profile along with a fast and efficient workflow.

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.

Management of incidental durotomies in an integrated Orthopaedic and Neurosurgical Spinal Unit

Introduction

Incidental durotomy (ID) is an intraoperative event associated to prolonged bed rest and hospital stay, antibiotic use, higher patient dissatisfaction, and leg pain among other complications of its postoperative course. Several repair techniques and postsurgical care have been proposed for its management. This study was designed to develop an agreed protocol in cases of ID among Orthopaedic Surgeons (OS) and Neurosurgeons (NS) integrated into a Spinal Surgery Unit.

Research question

Incidental durotomies management protocol.

Materials and methods

From 997 eligible cases operated in Hospital del Mar (Barcelona, Spain) from April 2018 to March 2022, demographic, clinical, surgical and postoperative data was collected for statistical analysis from the morbidity and mortality database, with 79 identified IDs. Redo procedures were significantly associated to OS, and cervical and anterior/lateral approaches to NS, both groups were not comparable.

Results

ID occurred in 7.9% of cases, more frequently after the lockdown (p=0.03), in females (p=0.04), during posterior approaches (p=0.003), and less frequently in the cervical spine (p=0.009). IDs were linked to postoperative infections (p< 0.001) and nerve root damage (p< 0.001). Patients without ID evolved more satisfactorily during the postoperative period (p=0.002), and those with CSF leak (20/79) spent on bed rest more than twice the time as those without (p<0.001). Multivariable logistic regression showed strong association between posterior approaches and ID, between complicated postoperative courses and ID.

Discussion and conclusions

ID is linked to an adverse postoperative recovery, and it should be primarily repaired under microscope, with early mobilization of patients after surgery.

Minimally invasive tubular microdiscectomy for recurrent lumbar disc herniation: step-by-step technical description with safe scar dissection

INTRODUCTION

Recurrent lumbar disc herniation (RLDH) is one of the most common reasons for re-operation after primary lumbar disc herniation with an incidence ranging from 5 to 23%. Numerous RLDH studies have been conducted; however, no available studies have provided a specific description of the use of the tubular retractor discectomy technique for RLDH emphasizing safe scar dissection. The objective of this study is to describe a detailed step-by-step technique for RLDH.

MATERIAL AND METHODS

A surgical technique reporting on our experience from the year 2013-2021 in 9 patients with RLDH at the same level and same side was included in the study. Clinical outcomes were assessed using the visual analog score (VAS) for leg pain before and three months after surgery.

RESULTS

A significant improvement was observed between the preoperative and postoperative VASs [mean (SD): 9.2 (1) vs. 1.5 (1)] for all patients. We did not report any incidental durotomy, neurological deficits or mortality in this study. One patient had superficial wound infection. The study is limited by small population, short follow-up and not reporting stability or spondylolisthesis.

CONCLUSION

A modified tubular discectomy technique with safe scar dissection is effective for RLDH treatment. Technically, the only scar needed to be dissected is the scar lateral to the exposed normal dura and the scar extended caudally till the level of the superior end plate of the targeted disc space where the scar can be entered ventrally and the disc fragment retrieved. Adherence to the step-by-step procedure described in our study will help surgeons operate with more confidence and minimize complications of recurrent lumbar disc herniation.

Use of a High-Fidelity Training Simulator for Minimally Invasive Lumbar Decompression Increases Working Knowledge and Technical Skills Among Orthopedic and Neurosurgical Trainees

STUDY DESIGN

Prospective comparative study.

OBJECTIVE

To quantify the educational benefit to surgical trainees of using a high-fidelity simulator to perform minimally invasive (MIS) unilateral laminotomy for bilateral decompression (ULBD) for lumbar stenosis.

METHODS

Twelve orthopedic and neurologic surgery residents performed three MIS ULBD procedures over 2 weeks on a simulator guided by established AO Spine metrics. Video recording of each surgery was rated by three blinded, independent experts using a global rating scale. The learning curve was evaluated with attention to technical skills, skipped steps, occurrence of errors, and timing. A knowledge gap analysis evaluating participants' current vs desired ability was performed after each trial.

RESULTS

From trial 1 to 3, there was a decrease in average procedural time by 31.7 minutes. The cumulative number of skipped steps and surgical errors decreased from 25 to 6 and 24 to 6, respectively. Overall surgical proficiency improved as indicated by video rating of efficiency and smoothness of surgical maneuvers, most notably with knowledge and handling of instruments. The greatest changes were noted in junior rather than senior residents. Average knowledge gap analysis significantly decreased by 30% from the first to last trial (P = .001), signifying trainees performed closer to their desired technical goal.

CONCLUSION

Procedural metrics for minimally invasive ULBD in combination with a realistic surgical simulator can be used to improve the skills and confidence of trainees. Surgical simulation may offer an important educational complement to traditional methods of skill acquisition and should be explored further with other MIS techniques.

Feasibility of High-Fidelity Simulator Models for Minimally Invasive Spine Surgery in a Resource-Limited Setting: Experience From East Africa

BACKGROUND

Spine surgery is a rapidly evolving specialty with a continuous need to learn new skills. In resource-limited settings such as Africa, the need for training is greater. The use of simulation-based training is important in different stages of skill acquisition, especially for high-stake procedures such as spine surgery. Among the available methods of simulation, the use of synthetic models has gained popularity among trainers.

METHOD

Twenty participants of a neurosurgery training course, most of whom (65%) were neurosurgery residents and fellows, were recruited. They had hands-on training sessions using a high-fidelity lumbar degenerative spine simulation model and hands-on theater experience. After this, they completed a survey to compare their experience and assess the effectiveness of the lumbar spine model in stimulating real patient and surgery experiences.

RESULTS

The participants were from four African countries, and the majority were neurosurgery residents. There were varying levels of experience among the participants in minimally invasive spine surgery, with the majority either having no experience or having only observed the procedure. All the participants said that the high-fidelity lumbar spine model effectively simulated real minimally invasive spine setup and real bone haptics and was effective in learning new techniques. Most of the participants agreed that the model effectively simulated real dura and nerve roots (95%), real muscle (90%), real bleeding from bones and muscles (95%), and real cerbrospinal fluid in the subarachnoid space. Among them, 95% agreed that the model is effective in lumbar minimally invasive spine training in resource-limited settings.

CONCLUSION

With the development of new and better surgical techniques, the use of high-fidelity models provides a good opportunity for learning and training, especially in resource-poor settings where there is a paucity of training facilities and personnel.

Preoperative cross-sectional area of psoas muscle correlates with short-term functional outcomes after posterior lumbar surgery

PURPOSE

To determine the optimal level for the measurement of psoas cross-sectional area and examine the correlation with short-term functional outcomes of posterior lumbar surgery.

METHODS

Patients who underwent minimally invasive posterior lumbar surgery were included in this study. The cross-sectional area of psoas muscle was measured at each intervertebral level on T2-weighted axial images of preoperative MRI. Normalized total psoas area (NTPA) (mm2/m2) was calculated as total psoas area normalized to patient height. Intraclass Correlation Coefficient (ICC) was calculated for the analysis of inter-rater reliability. Patient reported outcome measures including Oswestry disability index (ODI), visual analog scale (VAS), short form health survey (SF-12) and patient-reported outcomes measurement information system were collected. A multivariate analysis was performed to elucidate independent predictors associated with failure to reach minimal clinically important difference (MCID) in each functional outcome at 6 months.

RESULTS

The total of 212 patients were included in this study. ICC was highest at L3/4 [0.992 (95% CI: 0.987-0.994)] compared to the other levels [L1/2 0.983 (0.973-0.989), L2/3 0.991 (0.986-0.994), L4/5 0.928 (0.893-0.952)]. Postoperative PROMs were significantly worse in patients with low NTPA. Low NTPA was an independent predictor of failure to reach MCID in ODI (OR = 2.68; 95% CI: 1.26-5.67; p = 0.010) and VAS leg (OR = 2.43; 95% CI: 1.13-5.20; p = 0.022).

CONCLUSION

Decreased psoas cross-sectional area on preoperative MRI correlated with functional outcomes after posterior lumbar surgery. NTPA was highly reliable, especially at L3/4.

The "In-Parallel" Technique for Awake, Bilateral Simultaneous Minimally Invasive Transforaminal Lumbar Interbody Fusion and Multilevel Lumbar Decompression

BACKGROUND

Minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) and MIS lumbar decompression have been successfully undertaken in the absence of general anesthesia in well-selected patients. By leveraging spinal anesthesia, surgeons may safely conduct surgeries on one- or two-level lumbar pathology. However, surgeries on more extensive pathology have not yet been described, because of concerns about the duration of efficacy of spinal anesthetic in the awake patient.

OBJECTIVE

To report the use of a novel awake technique for "in parallel," simultaneous lumbar spinal surgery on three-segment pathology.

METHODS

We describe concurrent performance of a dual microscopic, navigated MIS TLIF and MIS two-level decompression, using a combination of liposomal bupivacaine erector spinae block in conjunction with a spinal anesthetic.

RESULTS

We show that a left-sided, two-level MIS tubular microscopic decompression combined with a concurrent right-sided, transfacet MIS TLIF via a tubular microscopic approach was well tolerated in an 87-year-old patient with multilevel lumbar stenosis with a mobile spondylolisthesis.

CONCLUSION

We provide the first description of a dual-surgeon approach for minimally invasive spine surgery. This "in-parallel" technique-reliant on 2, independent spine surgeons-may aid in the performance of surgeries previously considered too extensive, given the time constraints of regional anesthesia and can be successfully applied to patients who otherwise may not be candidates for general anesthesia.

En bloc resection of ligamentum flavum with laminotomy of the caudal lamina in the minimally invasive laminectomy: surgical anatomy and technique

OBJECTIVE

A CSF leak is a potential complication in a lumbar laminectomy. An analysis of the author's surgical experience identified inadvertent durotomies that occurred when resecting the ligamentum flavum at its insertion into the superior aspect of the caudal lamina. Anatomical analyses of the lumbar canal diameter demonstrate that the insertion point of the caudal ligamentum flavum is the most constrained area of the canal. The surgical technique was modified to eliminate the need for direct action in that anatomical region after the author compared the efficacy of piecemeal resection of the ligamentum flavum with en bloc resection with a laminotomy of the caudal lamina beyond the insertion point of the ligamentum flavum in the lumbar laminectomy.

METHODS

An analysis of a single surgeon's experience managing 147 consecutive patients with lumbar stenosis who underwent single-level lumbar hemilaminectomies over a 4-year period was performed. Patients were managed with either piecemeal resection (cohort 1) or en bloc resection with a laminotomy beyond the caudal insertion (cohort 2) of the ligamentum flavum.

RESULTS

Seventy-seven patients underwent piecemeal resection (cohort 1), and 70 underwent en bloc resection (cohort 2). There were 5 CSF leaks (6.4%) in cohort 1. There were no CSF leaks in cohort 2. There was a statistically significant difference in operative times between the two groups (p = 0.04), but there was no statistically significant difference in patient-reported outcomes at 6 months between the groups.

CONCLUSIONS

En bloc resection of the ligamentum flavum with a laminotomy below the caudal insertion point appears to decrease the risk of a CSF leak by working beyond the most constrained diameter of the lumbar canal to release the caudal insertion of the ligamentum flavum.

Ten-Step 3-Dimensional-Navigated Single-Stage Lateral Surgery With Microtubular Decompression: A Case Series

BACKGROUND

Single-stage lateral lumbar interbody fusion is a safe and effective procedure that relies on indirect decompression and fusion to treat various lumbar pathologies. This technique, however, has an overall 9% rate of indirect decompression failure, which may require additional surgery to achieve adequate direct decompression. To address this concern, we modified this technique by adding a minimally invasive, direct tubular decompression in lateral position when indicated. No study has described the technical nuances of incorporating a microtubular decompression into the single-stage lateral lumbar interbody fusion workflow (SSLLIF+).

OBJECTIVE

To report on the procedural steps and clinical outcomes of the SSLLIF+.

METHODS

In this retrospective case series of prospectively collected data, we present the detailed surgical approach of the SSLLIF+ with a single-center case series over a 5-year period. Surgical and clinical outcomes are presented.

RESULTS

A total of 7 patients underwent a SSLLIF+ with a total of 18 levels fused and 7 levels decompressed. The SSLLIF+ was successfully performed in all cases without the occurrence of intraoperative complications in this case series. There was 1 revision after 20 months of follow-up because of adjacent segment disease. There was no need for further direct decompression in a delayed fashion.

CONCLUSION

SSLLIF with direct microtubular decompression in lateral position is a safe and effective procedure in patients where indirect decompression alone may not achieve the surgical goal. Adherence to minimally invasive spine surgery principles and thoughtful patient selection facilitate the successful management of these patients while demonstrating short hospital stay and low-risk of perioperative complications.

Microsurgical Tubular Resection of Intradural Extramedullary Spinal Tumors With 3-Dimensional-Navigated Localization

BACKGROUND

The safety and efficacy of minimally invasive spine surgical (MISS) approaches have stimulated interest in adapting MISS principles for more complex pathology including intradural extramedullary (IDEM) tumors. No study has characterized a repeatable approach integrating the MISS surgical technique and 3-dimensional intraoperative navigated localization for the treatment of IDEM tumors.

OBJECTIVE

To describe a safe and reproducible technical guide for the navigated MISS technique for the treatment of benign intradural and extradural spinal tumors.

METHODS

Retrospective review of prospectively collected data on 20 patients who underwent navigated microsurgical tubular resection of intradural extramedullary tumors over a 5-year period. We review our approach to patient selection and report demographic and outcomes data for the cohort.

RESULTS

Our experience demonstrates technical feasibility and safety with a 100% rate of gross total resection with no patients demonstrating recurrence during an average follow-up of 20.2 months and no instances of perioperative complications. We demonstrate favorable outcomes regarding blood loss, operative duration, and hospital length of stay.

CONCLUSION

Navigated localization and microsurgical tubular resection of IDEM tumors is safe and effective. Adherence to MISS principles and thoughtful patient selection facilitate successful management of these patients.

Case Series of Tubular Retractor Assisted Minimally Invasive Extraforaminal L5/S1 Microdiskectomy

BACKGROUND

We present the largest series of tubular assisted minimally invasive extraforaminal L5/S1 microdiskectomy and describe the operative nuances. An extraforaminal L5/S1 disk herniation poses a surgical challenge as a result of limited access from a high iliac crest, the sacral ala, and the large transverse process of L5 necessitating oblique working angles.

METHODS

This is a case series of 28 consecutive patients who underwent tubular retractor-assisted minimally invasive extraforaminal L5/S1 microdiskectomy between 2017 and 2020 for L5 radiculopathy. Preoperative variables include demographics (age, gender); imaging characteristics (presence of spondylolisthesis, grade and presence of dynamic instability); and patient-reported measures of pain and function. Postoperatively, any complications, pain, and function were documented at 1-day, 3-month, and 12-months follow-up. Statistical analysis involved descriptive analysis of measured variables.

RESULTS

Patients (13 females and 15 males) had a median age of 62 years (range: 32-92). One patient demonstrated grade I spondylolisthesis with no dynamic instability. Twenty-six patients (93%) achieved complete pain resolution during the follow-up period. Two patients had persistent or recurrent radicular pain, 1 of whom resolved completely with a redo tubular retractor-assisted minimally invasive microdiskectomy. No other complications were noted during the postoperative follow-up.

CONCLUSIONS

Tubular retractor-assisted minimally invasive extraforaminal L5/S1 microdiskectomy is an effective approach. Good surgical outcomes are achieved while avoiding the complications associated with more invasive options such as open surgery or fusion.

Lumbar Giant Disk Herniations Treated With a Unilateral Approach for Bilateral Decompression

BACKGROUND

Disk herniations that obstruct the spinal canal by more than 50% are named "giant disk herniations" (GDHs). GDHs are challenging to treat from a surgical perspective because of their size and the risk of iatrogenic manipulation during resection resulting in additional neurological compromise. As a result, the appropriateness of minimally invasive tubular approaches for the treatment of lumbar GDHs remains controversial.

OBJECTIVE

To report our experience in treating lumbar GDHs using tubular minimally invasive surgery.

METHODS

A total number of 228 disk herniations were evaluated for the criteria of GDH. In addition, the presence of neurological deficits such as cauda equina syndrome, pain as measured by a visual analog scale, operating time, complications, estimated intraoperative blood loss, and number of surgical revisions were assessed. The standard tubular diskectomy technique was modified to include unilateral laminectomy for bilateral decompression before the diskectomy to create a sufficient working space for removal of the disk fragments.

RESULTS

Twenty-three (10%) patients met the criteria for GDH. Clinically significant motor weakness was present in 21 patients (91.3%) before surgery, and 3 patients (13%) presented with cauda equina syndrome. The average mean visual analog scale (±SD) for the preoperative pain score was 8.3 and decreased to 2.4 at follow-up after surgery. All cases of cauda equina syndrome resolved postoperatively.

CONCLUSION

Unilateral tubular minimally invasive surgery diskectomy seems to be a safe and effective treatment alternative for lumbar GDHs, combined with the "over-the-top" decompression, which provides bilateral decompression and working space.

Obesity and Spine Surgery: A Qualitative Review About Outcomes and Complications. Is It Time for New Perspectives on Future Researches?

STUDY DESIGN

Literature review.

OBJECTIVES

An increasing number of obese patients requires operative care for degenerative spinal disorders. The aim of this review is to analyze the available evidence regarding the role of obesity on outcomes after spine surgery. Peri-operative complications and clinical results are evaluated for both cervical and lumbar surgery. Furthermore, the contribution of MIS techniques for lumbar surgery to play a role in reducing risks has been analyzed.

METHODS

Only articles published in English in the last 10 years were reviewed. Inclusion criteria of the references were based on the scope of this review, according to PRISMA guidelines. Moreover, only paper analyzing obesity-related complications in spine surgery have been selected and thoroughly reviewed. Each article was classified according to its rating of evidence using the Sacket Grading System.

RESULTS

A total number of 1636 articles were found, but only 130 of them were considered to be relevant after thorough evaluation and according to PRISMA checklist. The majority of the included papers were classified according to the Sacket Grading System as Level 2 (Retrospective Studies).

CONCLUSION

Evidence suggest that obese patients could benefit from spine surgery and outcomes be satisfactory. A higher rate of peri-operative complications is reported among obese patients, especially in posterior approaches. The use of MIS techniques plays a key role in order to reduce surgical risks. Further studies should evaluate the role of multidisciplinary counseling between spine surgeons, nutritionists and bariatric surgeons, in order to plan proper weight loss before elective spine surgery.

Minimally Invasive Spine Surgery: An Overview

Spinal surgery is undergoing a major transformation toward a minimally invasive paradigm. This shift is being driven by multiple factors, including the need to address spinal problems in an older and sicker population, as well as changes in patient preferences and reimbursement patterns. Increasingly, minimally invasive surgical techniques are being used in place of traditional open approaches due to significant advancements and implementation of intraoperative imaging and navigation technologies. However, in some patients, due to specific anatomic or pathologic factors, minimally invasive techniques are not always possible. Numerous algorithms have been described, and additional efforts are underway to better optimize patient selection for minimally invasive spinal surgery (MISS) procedures in order to achieve optimal outcomes. Numerous unique MISS approaches and techniques have been described, and several have become fundamental. Investigators are evaluating combinations of MISS techniques to further enhance the surgical workflow, patient safety, and efficiency.

Innovations in Spinal Endoscopy

Innovations in spinal endoscopy technology and technique have broadened their applications during the past 10 years. Smaller outer-diameter working-channel endoscopes have permitted safe usage in the cervical spine for full endoscopic decompressions. Endoscopic fusions have now been widely reported, leveraging compatible instrumentation for disc preparation and expandable interbody grafts. This ultra-minimally invasive technique has also enabled the performance of fusion procedures in awake patients under monitored anesthesia care, affording speedier recovery and treatment options for those unable to undergo general anesthesia. Revision surgery after open or minimally invasive posterior discectomy or instrumentation can now be performed with endoscopic techniques, which often leverage the transforaminal approach to avoid scar tissue and adhesions. These procedures, among other endoscopic surgeries, are now being increasingly performed in ambulatory surgery centers, as safe outcomes, economic benefits to the healthcare system, and patients' desire to recover at home are becoming more apparent. Finally, the standardization of endoscopic terminology, which has long been a confounder to proper communication and education in this field, has recently been addressed by leading experts in a consensus document, which will serve as the foundation for future collaborative advancements.

Image Guidance in Spinal Surgery: A Critical Appraisal and Future Directions

BACKGROUND

Image-guided spinal surgery (IGSS) underwent rapid development over the past decades. The goal of IGSS is to increase patient safety and improve workflow. We present an overview of the history of IGSS, illustrate its current state, and highlight future developments. Currently, IGSS requires an image set, a tracking system, and a calibration method.

IMAGING

Two-dimensional images have many disadvantages as a source for navigation. Currently, the most common navigation technique is three-dimensional (3D) navigation based on cross-sectional imaging techniques such as cone-beam computed tomography (CT) or fan-beam CT.

TRACKING

Electromagnetic tracking uses an electromagnetic field to localize instruments. Optical tracking using infrared cameras has currently become one of the most common tracking methods in IGSS.

CALIBRATION

The three most common techniques currently used are the point-matching registration technique, the surface-matching registration technique, and the automated registration technique.

FUTURE

Augmented reality (AR) describes a computer-generated image that can be superimposed onto the real-world environment. Marking pathologies and anatomical landmarks are a few examples of many possible future applications. Additionally, AR offers a wide range of possibilities in surgical training. The latest development in IGSS is robotic-assisted surgery (RAS). The presently available data on RAS are very encouraging, but further improvements of these procedures is expected.

CONCLUSION

IGSS significantly evolved since its inception and is becoming a routinely used technology. In the future, IGSS will combine the advantages of "active/freehand 3D navigation" with AR and RAS and will one day find its way into all aspects of spinal surgery, not only in instrumented procedures.

Ten-Step Minimally Invasive Treatment of Lumbar Giant Disc Herniation via Unilateral Tubular Laminotomy for Bilateral Decompression: 2-Dimensional Operative Video

Giant disc herniation (GDH) is generally defined as a lumbar disc herniation that obstructs 50% or more of the space in the spinal canal.1-3 Common treatment options for GDH include unilateral interlaminar approach, bilateral approach, or open full laminectomy.4,5 Surgical treatment of GDH may be challenging because severe bilateral compression of neural elements in the spinal canal increases the risk of iatrogenic injury to nerve roots and dura. The surgical approach can be further complicated by calcification, hardening, and dehydration of the GDH tissue. The prevailing opinion in the literature is that giant disc herniations cannot safely be treated via tubular minimally invasive approaches.5-7 In this video, we present a case of a 52-yr-old male patient with a history of progressive low back pain that radiates bilaterally from the buttocks toward the posterior legs and knees for 2 yr because of a GDH at the L4-5 level. The patient was treated via a tubular "over-the-top" minimally invasive decompression in order to first provide generous bilateral decompression of neural elements and dura.8,9 After sufficient decompression at the surgical level, the discectomy was performed via an ipsilateral piecemeal resection of the GDH. The "over-the-top" contralateral mobilization of disc herniation was also achieved with this approach, which facilitated the removal of the entire disc fragment. Patient consent was obtained prior to performing the procedure. Therefore, GDH should not be considered as a contraindication for tubular decompression when this modified technique is performed.

Ten-Step Minimally Invasive Cervical Decompression via Unilateral Tubular Laminotomy: Technical Note and Early Clinical Experience

BACKGROUND

Minimally invasive techniques utilizing tubular retractors have become an increasingly popular approach to the spinal column. The concept of a unilateral laminotomy for bilateral decompression (ULBD), first applied in the lumbar spine, has recently been applied to the cervical spine for the treatment of cervical spondylotic myelopathy (CSM). A better understanding of the indications and surgical techniques is required to effectively educate surgeons on how to appropriately and safely perform tubular cervical laminotomy via ULBD.

OBJECTIVE

To describe a 10-step technique for minimally invasive cervical laminotomy and report our early clinical experience.

METHODS

A retrospective review identified 15 patients with CSM who were treated with this procedure. Visual analogue scale (VAS), neck disability index (NDI), and modified Japanese Orthopaedic Association (mJOA) scores were obtained pre- and postoperatively.

RESULTS

The mean age of the 15 patients was 73.1 ± 6.8 yr. The median number of levels treated was 1 (range 1-3). Mean operative time was 125.3 ± 30.8 or 81.7 ± 19.2 min per level. Mean estimated blood loss was 57.3 ± 24.6 cc. Median postoperative hospital length of stay was 36 h. No complications were encountered. Median follow-up was 18 mo. Mean pre- and postoperative VAS were 6.4 ± 2.4 and 1.0 ± 0.8, respectively (P < .001). Mean pre- and postoperative NDI were 46.4 ± 19.2 and 7.0 ± 6.9, respectively (P < .001). Mean pre- and postoperative Mjoa were 11.3 ± 2.5 and 14.5 ± 0.5, respectively (P < .001).

CONCLUSION

In our early clinical experience, minimally invasive cervical ULBD is safe and effective. Adherence to the presented 10-step technique will allow surgeons to safely address bilateral cervical pathology while avoiding complications.

Use of Intraoperative Computed Tomography Improves Outcome of Minimally Invasive Transforaminal Lumbar Interbody Fusion: A Single-Center Retrospective Cohort Study

OBJECTIVE

To provide data about surgical workflow, accuracy, complications, radiation exposure, and learning curve effect in patients who underwent minimally invasive (MIS) transforaminal lumbar interbody fusion with navigation coupled with mobile intraoperative computed tomography.

METHODS

A retrospective analysis was performed of data from consecutive patients who underwent single- or double-level MIS transforaminal lumbar interbody fusion at a single institution; mobile intraoperative computed tomography combined with a navigation system was used as the sole intraoperative imaging method to place pedicular screws; decompression and interbody fusion were performed through a 22-mm tubular retractor. Clinical data, perioperative complications, accuracy of pedicular screw placement, and radiation exposure were analyzed. A learning curve effect on surgical time and accuracy was assessed.

RESULTS

A total of 408 screws in 100 patients were analyzed. In all cases, spinal navigation allowed for identification of pedicular trajectories and greatly facilitated nerve root decompression through the MIS approach. Overall accuracy according to Heary classification was 95.3%. Nineteen screws (4.7%) presented a minor lateral breach (<2 mm), not clinically significant. Surgical time, blood loss, and patient radiation exposure compared favorably with reported values from other series using three-dimensional navigation. A learning curve effect on surgical time, but not on screw accuracy, was identified.

CONCLUSIONS

MIS transforaminal lumbar interbody fusion can now be performed without any radiation exposure to the surgeon and operating room staff, with almost absolute accuracy during screw positioning and tubular decompression. A learning curve effect on surgical time, but not on overall screw accuracy, may be expected.

Direct Pars Defect Tubular Decompression and TLIF for the Treatment of Low-Grade Adult Isthmic Spondylolisthesis: Surgical Challenges and Nuances of a Muscle-Sparing Minimally Invasive Approach

We present an illustrative report on the use of a minimally invasive, muscle-sparing, direct pars defect decompression with transforaminal lumbar interbody fusion (TLIF) and instrumentation for the treatment of low-grade adult isthmic spondylolysis with spondylolisthesis and discuss the surgical challenges and nuances associated with the technique.

Long-term pain relief following percutaneous steroid treatment of spinal synovial cysts: a population-based cohort study

BACKGROUND

Spinal synovial cysts are fluid-filled sacs that develop after facet joint degeneration and can give rise to radicular pain. If resistant to conservative management, surgical decompression or percutaneous steroid treatment is usually recommended. Percutaneous treatment minimizes the risk of spinal instability, but it has been uncertain whether it provides any long-term symptom relief. Moreover, it is unclear whether cyst rupture provides any added benefit.

OBJECTIVE

To assess long-term pain relief in patients with spinal synovial cysts who were treated with percutaneous intra-articular steroid treatment without cyst rupture.

METHODS

A population-based cohort-study was conducted of all patients with symptomatic synovial cysts who were treated with percutaneous intra-articular steroid treatment without cyst rupture between 1995 and 2014.

RESULTS

Thirty-eight patients were included. All patients had variations of lower back and radicular pain. Intra-articular access was achieved in 35 (92%) patients, and there were no treatment-related complications. At short-term assessment, 30 (79%) had pain relief. During the median follow-up of 11 years, 12 (32%) patients showed sustained pain relief without the need for decompressive surgery.

CONCLUSIONS

Percutaneous intra-articular steroid treatment without cyst rupture is a safe treatment for symptomatic spinal synovial cysts and eliminates the need for surgery in a substantial number of patients. It can be suggested as a first line of treatment.

A Review of Techniques, Time Demand, Radiation Exposure, and Outcomes of Skin-anchored Intraoperative 3D Navigation in Minimally Invasive Lumbar Spinal Surgery

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

To describe our technique for and evaluate the time demand, radiation exposure and outcomes of skin-anchored intraoperative three-dimensional navigation (ION) in minimally invasive (MIS) lumbar surgery, and to compare these parameters to 2D fluoroscopy for MI-TLIF.

SUMMARY OF BACKGROUND DATA

Limited visualization of anatomic landmarks and narrow access corridor in MIS procedures result in greater reliance on image guidance. Although two-dimensional fluoroscopy has historically been used, ION is gaining traction.

METHODS

Patients who underwent MIS lumbar microdiscectomy, laminectomy, or MI-TLIF using skin-anchored ION and MI-TLIF by the same surgeon using 2D fluoroscopy were selected. Operative variables, radiation exposure, and short-term outcomes of all procedures were summarized. Time-demand and radiation exposure of fluoroscopy and ION for MI-TLIF were compared.

RESULTS

Of the 326 patients included, 232 were in the ION cohort (92 microdiscectomies, 65 laminectomies, and 75 MI-TLIFs) and 94 in the MI-TLIF using 2D fluoroscopy cohort. Time for ION setup and image acquisition was a median of 22 to 24 minutes. Total fluoroscopy time was a median of 10 seconds for microdiscectomy, 9 for laminectomy, and 26 for MI-TLIF. Radiation dose was a median of 15.2 mGy for microdiscectomy, 16.6 for laminectomy, and 44.6 for MI-TLIF, of this, 93%, 95%, and 37% for microdiscectomy, laminectomy, and MI-TLIF, respectively were for ION image acquisition, with the rest attributable to the procedure. There were no wrong-level surgeries. Compared with fluoroscopy, ION for MI-TLIF resulted in lower operative times (92 vs. 108 min, P < 0.0001), fluoroscopy time (26 vs. 144 s, P < 0.0001), and radiation dose (44.6 vs. 63.1 mGy, P = 0.002), with equivalent time-demand and length of stay. ION lowered the radiation dose by 29% for patients and 55% for operating room personnel.

CONCLUSION

Skin-anchored ION does not increase time-demand compared with fluoroscopy, is feasible, safe and accurate, and results in low radiation exposure.

LEVEL OF EVIDENCE

3.

Tandem Microscopic Slalom Technique: The Use of 2 Microscopes Simultaneously Performing Unilateral Laminotomy for Bilateral Decompression in Multilevel Lumbar Spinal Stenosis

STUDY DESIGN

Technical note, retrospective case series.

OBJECTIVE

Lumbar stenosis can be effectively treated using tubular unilateral laminotomy for bilateral decompression (ULBD). For multilevel stenosis, a multilevel ULBD through separate, alternating crossover approaches has been described as the "slalom technique." To increase efficacy, we introduced this approach with 2 microscopes simultaneously.

METHODS

We collected data on 13 patients, with multilevel lumbar stenosis, operated at our institution between 2015 and 2016 by the aforementioned technique. We assessed surgical time (ST), estimated blood loss (EBL), complications, and revision surgeries. Furthermore, we provide a stepwise instruction for performing the tandem microscopic slalom technique in a safe and efficient manner.

RESULTS

The mean age of the patients was 68 ± 8 years. The ST per level was 68 ± 19 minutes with an EBL per level of 39 ± 30 mL. We had no intraoperative complications and none of our patients required a revision surgery during a mean follow-up of 12 months.

CONCLUSIONS

We have shown that this technique is feasible and can be performed safely for multisegmental lumbar spinal stenosis with minimal tissue trauma and low EBL. Furthermore, randomized controlled studies with a larger sample size may be necessary to drive any final conclusions.

Minimally invasive unilateral lumbar interbody fusion (UNILIF) in over-80-year-olds. Continuous series of 42 patients at 1.4 years' follow-up

INTRODUCTION

In lumbar stenosis, surgery aims to improve quality of life in increasingly elderly patients. Minimally invasive techniques better suit the requirements of elderly patients with increasing functional demand.

HYPOTHESIS

The UNILIF unilateral lumbar interbody fusion technique improves functional scores at 1 year in over-80 year-olds, with low morbidity.

METHOD

Patients undergoing minimally invasive decompression with transforaminal lumbar interbody fusion (TLIF) associated to unilateral pedicle screwing for degenerative lumbar stenosis were analyzed at a minimum 1 year's follow-up. SF12, Oswestry Disability Index (ODI) and Quebec scores and sagittal spinopelvic radiographic parameters were assessed at follow-up. Surgical and general complications were also collated.

RESULTS

In all, 42 patients (64.3% female; mean age, 83.7±2.9 years) were treated by UNILIF at levels L2-L3 (3.8%), L3-L4 (15.4%), L4-L5 (71.2%) and L5-S1 (9.6%). Mean follow-up was 520±226 days (range, 340-1166 days). Mean preoperative SF12 score was 77.5±10.9, with significant improvement at last follow-up: 81.9±138 (p<0.05). Mean preoperative ODI was 44.4%±14.0, with significant improvement at last follow-up: 32.4%±13.3 (p<0.001). Mean preoperative Quebec score was 42.9±19.9, with significant improvement at last follow-up: 28.5±21.9 (p<0.001). Spinopelvic sagittal balance was not affected by the UNILIF procedure. There were no cases of infection or severe general complications during follow-up, although 2 cases of non-union required revision surgery.

CONCLUSION

Lumbar stenosis surgery by UNILIF improved functional scores at 1 year, with low morbidity. It is a suitable strategy for degenerative lumbar stenosis in elderly patients.

LEVEL OF EVIDENCE

IV, non-comparative cohort 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.

Comparison of full-endoscopic and minimally invasive decompression for lumbar spinal stenosis in the setting of degenerative scoliosis and spondylolisthesis

OBJECTIVE

The management of lumbar spinal stenosis (LSS) with concurrent scoliosis and/or spondylolisthesis remains controversial. Full-endoscopic unilateral laminotomy for bilateral decompression (ULBD) facilitates neural decompression while preserving stabilizing osseoligamentous structures and may be uniquely suited for the treatment of LSS with concurrent mild to moderate degenerative deformity. The safety and efficacy of full-endoscopic versus minimally invasive surgery (MIS) ULBD in this patient population is studied here for the first time.

METHODS

A retrospective analysis of prospectively collected data was conducted on 45 consecutive LSS patients with concurrent scoliosis (≥ 10° coronal Cobb angle) and/or spondylolisthesis (≥ 3 mm). Patient demographics, operative details, complications, and imaging characteristics were reviewed. Outcomes were quantified using back and leg visual analog scale (VAS) scores and the Oswestry Disability Index (ODI) at 2 weeks, 3 months, and 1 year.

RESULTS

A total of 26 patients underwent full-endoscopic and 19 underwent MIS-ULBD with an average follow-up period of 12 months. The endoscopic cohort experienced a significantly shorter hospital length of stay (p = 0.014) and fewer adverse events (p = 0.010). Both cohorts experienced significant improvements in VAS and ODI scores at all time points (p < 0.001), but the endoscopic cohort demonstrated significantly better early ODI scores (p = 0.024).

CONCLUSIONS

Endoscopic and MIS-ULBD result in similar functional outcomes for LSS with mild to moderate deformity, while the endoscopic approach demonstrates a favorable rate of complications. Further studies are required to better delineate the characteristics of spinal deformities amenable to this approach and the durability of functional results.

Minimally Invasive Approaches for Surgical Treatment of Lumbar Spondylolisthesis

The unilateral laminotomy for bilateral decompression initially was described in the late 1990s and has evolved in conjunction with minimally invasive surgical instrumentation. This technique has been shown to significantly improve bilateral symptoms regardless of the side of approach. It also can be used for multilevel decompressions using the slalom technique with alternating lateralizing sites of access. The over-the-top technique involving a unilateral approach for bilateral decompression helps preserve the posterior tension band and can accomplish the operative goals with better clinical outcomes than traditional open approaches.

Comparison of clinical outcomes following minimally invasive or lumbar endoscopic unilateral laminotomy for bilateral decompression

OBJECTIVE

Minimally invasive lumbar unilateral tubular laminotomy for bilateral decompression has gradually gained acceptance as a less destabilizing but efficacious and safe alternative to traditional open decompression techniques. The authors have further advanced the principles of minimally invasive surgery (MIS) by utilizing working-channel endoscope-based techniques. Full-endoscopic technique allows for high-resolution off-axis visualization of neural structures within the lateral recess, thereby minimizing the need for facet joint resection. The relative efficacy and safety of MIS and full-endoscopic techniques have not been directly compared.

METHODS

A retrospective analysis of 95 consecutive patients undergoing either MIS (n = 45) or endoscopic (n = 50) unilateral laminotomies for bilateral decompression in cases of lumbar spinal stenosis was performed. Patient demographics, operative details, clinical outcomes, and complications were reviewed.

RESULTS

The patient cohort consisted of 41 female and 54 male patients whose average age was 62 years. Half of the patients had single-level, one-third had 2-level, and the remaining patients had 3- or 4-level procedures. The surgical time for endoscopic technique was significantly longer per level compared to MIS (161.8 ± 6.8 minutes vs 99.3 ± 4.6 minutes; p < 0.001). Hospital stay for MIS patients was on average 2.4 ± 0.5 days compared to 0.7 ± 0.1 days for endoscopic patients (p = 0.001). At the 1-year follow-up, endoscopic patients had a significantly lower visual analog scale score for leg pain than MIS patients (1.3 ± 0.3 vs 3.0 ± 0.5; p < 0.01). Moreover, the back pain disability index score was significantly lower in the endoscopic cohort than in the MIS cohort (20.7 ± 3.4 vs 35.9 ± 4.1; p < 0.01). Two patients in the MIS group (epidural hematoma) and one patient in the endoscopic group (disc herniation) required a return to the operating room acutely after surgery (< 14 days).

CONCLUSIONS

Lumbar endoscopic unilateral laminotomy for bilateral decompression is a safe and effective surgical procedure with favorable complication profile and patient outcomes.

"One and a half" minimally invasive transforaminal lumbar interbody fusion: single level transforaminal lumbar interbody fusion with adjacent segment unilateral laminotomy for bilateral decompression for spondylolisthesis with bisegmental stenosis

Symptomatic lumbar spondylolisthesis is commonly accompanied by spinal stenosis in multiple segments. These pathologies are routinely treated by multilevel decompression and instrumented fusion. However, it was hypothesized that a minimally invasive surgery (MIS) fusion in the unstable segment combined with a unilateral laminotomy for bilateral decompression (ULBD) in the adjacent stenotic segment is a biomechanically feasible alternative to a two-level fusion and superior to open laminectomy adjacent to a fused segment. This concept has demonstrated success in a recently published biomechanical cadaver study performed by our group. The present article offers a detailed step by step technical description for an MIS-TLIF (transforaminal lumbar interbody fusion) with adjacent ULBD.

Percutaneous Total Endoscopic Resection of Partial Articular Processes for Treatment of Lateral Crypt Stenosis and Lumbar Spinal Stenosis: Technical Report and Efficacy Analysis

Objective

To observe the clinical curative effect of posterior total endoscopic precision decompression for the treatment of single-segment lateral crypt lumbar spinal stenosis (LSS).

Method

A total of 27 patients with single-segment LSS satisfying the inclusion criteria were recruited from July 2013 to September 2015. There were 18 cases of unilateral stenosis of the L_4-5 segments and 9 cases of unilateral stenosis of the L₅-S₁ segment. All patients were treated via the posterior approach with the precise lateral crypt decompression technique. Precise decompression was performed on the narrow areas causing clinical symptoms. Clinical efficacy was assessed at 3 days, 3 months, 6 months, and 2 years after surgery. Low-back pain and sciatic nerve pain assessed by visual analog scale (VAS) score and the functional Oswestry Disability Index (ODI) were used to evaluate lumbar function, and modified MacNab score criteria were used to investigate long-term efficacy.

Result

All patients completed the operation successfully, and the follow-up time was 2 years. The VAS score of lumbago was lower after than before surgery (preoperative: 6.96±0.90; postoperative: 2.04±1.02, P<0.05). The VAS score of sciatica was also lower after than before surgery (preoperative: 7.19±0.88, postoperative: 1.93±0.92, P<0.05), and the ODI was improved at the last follow-up (29.62±4.26) % compared with before surgery (80.07±3.98) %. The MacNab efficacy evaluation showed improvement at the end of the follow-up period: 20 cases were excellent, 6 cases were good, and 1 case was satisfactory, with a good/excellent rate of 96%. No surgical site infections, iatrogenic nerve root injuries, epidural hematomas, or other complications occurred.

Conclusion

Total endoscopic decompression of posterior facet arthrodesis for the treatment of single-segment lateral crypt LSS has the advantages of safety, reduced recurrence and trauma, and a satisfactory curative effect. This trial is registered with ChiCTR1800015628.

Interlaminar endoscopic lateral recess decompression-surgical technique and early clinical results

BACKGROUND

Lateral recess stenosis is a common pathology causing de-novo or residual radicular pain following lumbar spine surgery. Diagnostic criteria and treatment strategies for symptomatic lateral recess stenosis are not well established.

METHODS

We identified ten patients in our prospective patient database (n=146) who underwent endoscopic interlaminar decompression for unilateral symptomatic lateral recess stenosis. Lateral recess height and angle were measured on axial T2-weighted MRI. Values from the symptomatic side were compared to the contralateral side which served as asymptomatic control. Oswestry Disability Index (ODI) and Visual Analogue Scale (VAS) for back and leg pain were collected preoperatively, postoperatively and at last follow-up.

RESULTS

Preoperative MRI revealed that both lateral recess angle and height were significantly smaller on the symptomatic compared to the asymptomatic side (angle: 19.3° vs. 35.7°; height: 2.9 vs. 5.7 mm; P<0.01). All patients tolerated endoscopic interlaminar decompression well and half of the patients were discharged on the day of surgery. At last follow-up (12.6±1.7 months), 8 out of 10 patients experienced a minimally clinically important improvement of their VAS for ipsilateral leg pain, which improved from 7.2±0.5 preoperatively to 2.5±0.8 postoperatively (P=0.001). The back pain VAS also improved (preoperatively 5.1±1.1 vs. postoperatively 1.7±0.9, P<0.05). The ODI improved from 50±5.8 preoperatively to 22.2±5.1 at last follow-up (P=0.001). One patient experienced persistent leg pain.

CONCLUSIONS

Lateral recess height and angle correlate with symptomatic lateral recess stenosis which is effectively treated utilizing interlaminar endoscopic lateral recess decompression.

Total Navigation in Spine Surgery; A Concise Guide to Eliminate Fluoroscopy Using a Portable Intraoperative Computed Tomography 3-Dimensional Navigation System

BACKGROUND

Portable intraoperative computed tomography (iCT) with integrated 3-dimensional navigation (NAV) offers new opportunities for more precise navigation in spinal surgery, eliminates radiation exposure for the surgical team, and accelerates surgical workflows. We present the concept of "total navigation" using iCT NAV in spinal surgery. Therefore, we propose a step-by-step guideline demonstrating how total navigation can eliminate fluoroscopy with time-efficient workflows integrating iCT NAV into daily practice.

METHODS

A prospective study was conducted on collected data from patients undergoing iCT NAV-guided spine surgery. Number of scans, radiation exposure, and workflow of iCT NAV (e.g., instrumentation, cage placement, localization) were documented. Finally, the accuracy of pedicle screws and time for instrumentation were determined.

RESULTS

iCT NAV was successfully performed in 117 cases for various indications and in all regions of the spine. More than half (61%) of cases were performed in a minimally invasive manner. Navigation was used for skin incision, localization of index level, and verification of implant position. iCT NAV was used to evaluate neural decompression achieved in spinal fusion surgeries. Total navigation eliminates fluoroscopy in 75%, thus reducing staff radiation exposure entirely. The average times for iCT NAV setup and pedicle screw insertion were 12.1 and 3.1 minutes, respectively, achieving a pedicle screw accuracy of 99%.

CONCLUSIONS

Total navigation makes spine surgery safer and more accurate, and it enhances efficient and reproducible workflows. Fluoroscopy and radiation exposure for the surgical staff can be eliminated in the majority of cases.