Image-guided navigation and video-assisted thoracoscopic spine surgery: the second generation

Endoscopic Versus Traditional Thoracic Discectomy: A Multicenter Retrospective Case Series and Meta-Analysis

BACKGROUND AND OBJECTIVES

Surgical treatment for symptomatic thoracic disc herniations (TDH) involves invasive open surgical approaches with relatively high complication rates and prolonged hospital stays. Although advantages of full endoscopic spine surgery (FESS) are well-established in lumbar disc herniations, data are limited for the endoscopic treatment of TDH despite potential benefits regarding surgical invasiveness. The aim of this study was to provide a comprehensive evaluation of potential benefits of FESS for the treatment of TDH.

METHODS

PubMed, MEDLINE, EMBASE, and Scopus were systematically searched for the term "thoracic disc herniation" up to March 2023 and study quality appraised with a subsequent meta-analysis. Primary outcomes were perioperative complications, need for instrumentation, and reoperations. Simultaneously, we performed a multicenter retrospective evaluation of outcomes in patients undergoing full endoscopic thoracic discectomy.

RESULTS

We identified 3190 patients from 108 studies for the traditional thoracic discectomy meta-analysis. Pooled incidence rates of complications were 25% (95% CI 0.22-0.29) for perioperative complications and 7% (95% CI 0.05-0.09) for reoperation. In this cohort, 37% (95% CI 0.26-0.49) of patients underwent instrumentation. The pooled mean for estimated blood loss for traditional approaches was 570 mL (95% CI 477.3-664.1) and 7.0 days (95% CI 5.91-8.14) for length of stay. For FESS, 41 patients from multiple institutions were retrospectively reviewed, perioperative complications were reported in 4 patients (9.7%), 4 (9.7%) required revision surgery, and 6 (14.6%) required instrumentation. Median blood loss was 5 mL (IQR 5-10), and length of stay was 0.43 days (IQR 0-1.23).

CONCLUSION

The results suggest that full endoscopic thoracic discectomy is a safe and effective treatment option for patients with symptomatic TDH. When compared with open surgical approaches, FESS dramatically diminishes invasiveness, the rate of complications, and need for prolonged hospitalizations. Full endoscopic spine surgery has the capacity to alter the standard of care for TDH treatment toward an elective outpatient surgery.

Management of Spinal Metastasis by Minimally Invasive Surgical Techniques: Surgical Principles and Indications-A Literature Review

BACKGROUND

Spinal metastasis is becoming more frequent. This raises the topics of pain and neurological complications, which worsen the functional and survival prognosis of oncological population patients. Surgical treatment must be as complete as possible in order to decompress and stabilize without delaying the management of the oncological disease. Minimally invasive spine surgical techniques inflict less damage on the musculocutaneous plan than opened ones.

METHODS

Different minimally invasive techniques are proposed in this paper for the management of spinal metastasis. We used our experience, developed degenerative and traumatic pathologies, and referred to many authors, establishing a narrative review of our local practice.

RESULTS

Forty-eight articles were selected, and these allowed us to describe the different techniques: percutaneous methods such as vertebro/kyphoplasty, osteosynthesis, mini-open surgery, or that through a posterior or anterior approach. Also, some studies detail the contribution of new technologies, such as intraoperative CT scan and robotic assistance.

CONCLUSIONS

It seems essential to offer a lasting solution to a spinal problem, such as in the form of pain relief, stabilization, and decompression. Our department has embraced a multidisciplinary and multidimensional approach to MISS, incorporating cutting-edge technologies and evidence-based practices.

Augmented Reality in Spinal Surgery: Highlights From Augmented Reality Lectures at the Emerging Technologies Annual Meetings

Introduction

Augmented reality (AR) is an advanced technology and emerging field that has been adopted into spine surgery to enhance care and outcomes. AR superimposes a three-dimensional computer-generated image over the normal anatomy of interest in order to facilitate visualization of deep structures without the ability to directly see them.

Objective

To summarize the latest literature and highlight AR from the annual “Spinal Navigation, Emerging Technologies and Systems Integration” meeting lectures presented by the Seattle Science Foundation (SSF) on the development and use of augmented reality in spinal surgery. 

Methods

 We performed a comprehensive literature review from 2016 to 2020 on PubMed to correlate with lectures given at the annual “Emerging Technologies” conferences. After the exclusion of papers that concerned non-spine surgery specialties, a total of 54 papers concerning AR in spinal applications were found. The articles were then categorized by content and focus.

Results

The 54 papers were divided into six major focused topics: training, proof of concept, feasibility and usability, clinical evaluation, state of technology, and nonsurgical applications. The greatest number of papers were published during 2020. Each paper discussed varied topics such as patient rehabilitation, proof of concept, workflow, applications in neurological and orthopedic spine surgery, and outcomes data.

Conclusions

The recent literature and SSF lectures on AR provide a solid base and demonstrate the emergence of an advanced technology that offers a platform for an advantageous technique that is superior, in that it allows the operating surgeon to focus directly on the patient rather than a guidance screen.

Spinal navigation applied to the anterior approach for the resection of thoracic disc herniation: patient series

BACKGROUND

Thoracic disc herniation (TDH) represents a challenge for spine surgeons. The goal of this study is to report the surgical technique and clinical results concerning the application of navigation to anterior transthoracic approaches.

OBSERVATIONS

Between 2017 and 2019, 8 patients with TDH were operated in the lateral decubitus by means of mini-open thoracotomy. An adapted patient referent frame was secured to the iliac wing. The high-speed drill was also navigated. Intraoperative three-dimensional scans were used for level identification, optimized drilling trajectory, and assessment of complete resection. At 12 months follow up, all patients were ambulatory. Seven out of 8 patients (87%) experienced a postoperative neurological improvement. We observed 2 postoperative complications: 1 case of pleural effusion and 1 case of abdominal wall weakness.

LESSONS

In order to increase the safety of anterior transthoracic discectomy, the authors applied the concepts of spinal navigation to the thoracotomy setting. The advantages of this technique include decrease in wrong-level procedure, continuous matching of intraoperative and navigation anatomical findings, better exposure of the TDH, optimized vertebral body drilling, and minimized risk of neurological damage. In conclusion, the authors consider spinal navigation as an important resource for the surgical treatment of patients with TDH.

Video-assisted thoracoscopic image-guided spine surgery: evolution of 19 years of experience, from endoscopy to fully integrated 3D navigation

OBJECTIVE

The purpose of this study was to describe the evolution of thoracoscopic spine surgery from basic endoscopic procedures using fluoroscopy and anatomical localization through developmental iterations to the current technology use in which endoscopy and image-guided surgery are merged with intraoperative CT scanning.

METHODS

The authors provided detailed explanations of their thoracoscopic spine surgery techniques, beginning with their early-generation endoscopy with fluoroscopic localization, which was followed with point surface matching techniques and early image guidance. The authors supplanted this with the modern era of image guidance, thoracoscopic spine surgery, and seamless integration that has reached its current level of refinement.

RESULTS

A retrospective review of single-institution thoracoscopic procedures performed by the senior author over the course of 19 years yielded a total of 160 patients, including 73 women and 87 men. The mean patient age was 55 years, and the range included patients 16-94 years of age. There were no patients with worsened neurological function. One hundred sixteen patients underwent surgery for thoracic disc herniation, 18 for underlying neoplasms with spinal cord compression, 14 for osteomyelitis and discitis, 12 for thoracic deformity with neurological changes, and 8 for traumatic etiologies.

CONCLUSIONS

More than 19 years of experience has revealed the benefits of integrating thoracoscopic spine surgery with intraoperative CT scanning and image-guided surgery, including direct decompression without manipulation of neural elements, superior 3D spatial orientation, and localization of complex spinal anatomy. With the exponential growth of machine learning, robotics, artificial intelligence, and advances in imaging techniques and endoscopic imaging, there may be further refinements of this technique on the horizon.

Thoracic Endoscopic Spine Surgery: A Comprehensive Review

BACKGROUND

From the 1990s, there has been growth in the literature demonstrating the feasibility of minimally invasive approaches for treating diverse spinal disorders. There is still much work to be done in circumnavigating the technical challenges and elucidating relative advantages of endoscopic techniques in spine surgery. In this comprehensive literature review, we discuss the history, advantages, disadvantages, approaches, and technology of, and critically examine peer-reviewed studies specifically addressing, endoscopic thoracic spinal surgery.

METHODS

Literature review was conducted with the key words "endoscopic," "minimally invasive," and "thoracic spinal surgery," using PubMed, Web of Science, and Google Scholar.

RESULTS

Review of 241 thorascopic procedures showed a success rate of 98% to 100%, low morbidity, and favorable complication profile. Review of 115 thoracic fixation procedures demonstrated high success rate, and 87% of screw positions were rated "good." Review of 55 full endoscopic uniportal decompressions showed sufficient decompression in most patients. Match pair analysis of 34 patients comparing video-assisted thoracoscopy surgery (VATS) or posterior spinal fusion reported the VATS group had increased operative duration but reduced blood loss.

CONCLUSIONS

Based on our literature review, there is a high rate of positive outcomes with endoscopic thoracic spine surgery, which reduces tissue dissection, intraoperative blood loss, and epidural fibrosis. However, the technical challenge highlights the importance of further training and innovation in this rapidly evolving field.

LEVEL OF EVIDENCE

3.

CLINICAL RELEVANCE

There is growing evidence demonstrating the success of endoscopic thoracic spinal surgery. Populations that could be helped include the elderly and immunocompromised, who would benefit from decreased hospital stay and enhanced recovery time.

Three-Dimensional Thoracoscopic Surgery for Spine Fractures: A Technical Report With First Results and Experiences

STUDY DESIGN

Technical report.

OBJECTIVES

Conventional 2-dimensional (2D) video-assisted thoracoscopy (VATS) is a technical procedure mainly performed by experienced surgeons. The technique may, however, come with difficulties in hand-eye coordination and estimation of depth. Three-dimensional thoracoscopy can help overcome these difficulties by providing a stereoscopic 3D view. The objective of this study is to report the first experience and results with 3D thoracoscopy for spine surgery in trauma patients.

METHODS

The first 4 patients treated with anterior stabilization for traumatic spine fractures using 3D thoracoscopy in an academic hospital are described. Baseline characteristics, operative time, and blood loss were retrospectively collected. This data is compared with a cohort of patients treated in the same center with the conventional 2D technique. Additionally, the treating surgeons' and residents' experience with the technique is described. Surgical equipment consists of 3D compatible video monitors, a videoscope with 2 cameras, and special glasses to be worn by the personnel.

RESULTS

Four patients were successfully treated using 3D thoracoscopy. Operative time was comparable to that of the conventional 2D technique and less blood loss occurred. No per- or postoperative complications or problems occurred. Per-operative views were of very high quality and provided improved depth perception. Surgeons and residents deemed the technique helpful, especially during technically demanding aspects of the procedure.

CONCLUSIONS

While a shorter learning curve, decreased surgery time, and blood loss have to be proven in future prospective studies, the first experience with 3D-VATS for spine surgery is positive, and future use in minimally invasive spine surgery seems feasible.

Automatic Global Level Set Approach for Lumbar Vertebrae CT Image Segmentation

Vertebrae computed tomography (CT) image automatic segmentation is an essential step for Image-guided minimally invasive spine surgery. However, most of state-of-the-art methods still require human intervention due to the inherent limitations of vertebrae CT image, such as topological variation, irregular boundaries (double boundary, weak boundary), and image noise. Therefore, this paper intentionally designed an automatic global level set approach (AGLSA), which is capable of dealing with these issues for lumbar vertebrae CT image segmentation. Unlike the traditional level set methods, we firstly propose an automatically initialized level set function (AILSF) that comprises hybrid morphological filter (HMF) and Gaussian mixture model (GMM) to automatically generate a smooth initial contour which is precisely adjacent to the object boundary. Secondly, a regularized level set formulation is introduced to overcome the weak boundary leaking problem, which utilizes the region correlation of histograms inside and outside the level set contour as a global term. Ultimately, a gradient vector flow (GVF) based edge-stopping function is employed to guarantee a fast convergence rate of the level set evolution and to avoid level set function oversegmentation at the same time. Our proposed approach has been tested on 115 vertebrae CT volumes of various patients. Quantitative comparisons validate that our proposed AGLSA is more accurate in segmenting lumbar vertebrae CT images with irregular boundaries and more robust to various levels of salt-and-pepper noise.

Accuracy of pedicle screw insertion by AIRO® intraoperative CT in complex spinal deformity assessed by a new classification based on technical complexity of screw insertion

PURPOSE

To develop a classification based on the technical complexity encountered during pedicle screw insertion and to evaluate the performance of AIRO^® CT navigation system based on this classification, in the clinical scenario of complex spinal deformity.

MATERIALS AND METHODS

31 complex spinal deformity correction surgeries were prospectively analyzed for performance of AIRO^® mobile CT-based navigation system. Pedicles were classified according to complexity of insertion into five types. Analysis was performed to estimate the accuracy of screw placement and time for screw insertion. Breach greater than 2 mm was considered for analysis.

RESULTS

452 pedicle screws were inserted (T1-T6: 116; T7-T12: 171; L1-S1: 165). The average Cobb angle was 68.3° (range 60°-104°). We had 242 grade 2 pedicles, 133 grade 3, and 77 grade 4, and 44 pedicles were unfit for pedicle screw insertion. We noted 27 pedicle screw breach (medial: 10; lateral: 16; anterior: 1). Among lateral breach (n = 16), ten screws were planned for in-out-in pedicle screw insertion. Among lateral breach (n = 16), ten screws were planned for in-out-in pedicle screw insertion. Average screw insertion time was 1.76 ± 0.89 min. After accounting for planned breach, the effective breach rate was 3.8% resulting in 96.2% accuracy for pedicle screw placement.

CONCLUSION

This classification helps compare the accuracy of screw insertion in range of conditions by considering the complexity of screw insertion. Considering the clinical scenario of complex pedicle anatomy in spinal deformity AIRO^® navigation showed an excellent accuracy rate of 96.2%.

Resection of spinal column tumors utilizing image-guided navigation: a multicenter analysis

OBJECTIVE The use of intraoperative stereotactic navigation has become more available in spine surgery. The authors undertook this study to assess the utility of intraoperative CT navigation in the localization of spinal lesions and as an intraoperative tool to guide resection in patients with spinal lesions. METHODS This was a retrospective multicenter study including 50 patients from 2 different institutions who underwent biopsy and/or resection of spinal column tumors using image-guided navigation. Of the 50 cases reviewed, 4 illustrative cases are presented. In addition, the authors provide a description of surgical technique with image guidance. RESULTS The patient group included 27 male patients and 23 female patients. Their average age was 61 ± 17 years (range 14-87 years). The average operative time (incision to closure) was 311 ± 188 minutes (range 62-865 minutes). The average intraoperative blood loss was 882 ± 1194 ml (range 5-7000 ml). The average length of hospitalization was 10 ± 8.9 days (range 1-36 days). The postoperative complications included 2 deaths (4.0%) and 4 radiculopathies (8%) secondary to tumor burden. CONCLUSIONS O-arm 3D imaging with stereotactic navigation may be used to localize lesions intraoperatively with real-time dynamic feedback of tumor resection. Stereotactic guidance may augment resection or biopsy of primary and metastatic spinal tumors. It offers reduced radiation exposure to operating room personnel and the ability to use minimally invasive approaches that limit tissue injury. In addition, acquisition of intraoperative CT scans with real-time tracking allows for precise targeting of spinal lesions with minimal dissection.

Transpedicular Approach to Thoracic Disc Herniaton Guided by 3D Navigation System

BACKGROUND

The choice of surgical approach for thoracic disc herniation should consider the location on the axial plane and the consistency of the herniated disc. Calcified midline disc herniations are difficult to remove with a transpedicular approach because of limitations due to blind spots; so they are usually treated via a transthoracic approach, although this entails a high risk of thoracopulmonary injuries.

METHODS

In this work we present two cases of calcified midline thoracic disc herniations treated with a transpedicular approach, improved by using a three-dimensional (3D) neuronavigation system to verify the extent of removal on the blind side.

RESULTS

Postoperative computed tomography (CT) scans demonstrated that this original technical innovation, in the two present cases, allowed us to reach the side opposite the disc herniation and to assess the extent of resection at the end of the procedure.

CONCLUSIONS

The employment of a neuronavigation system in the transpedicular approach allowed safe and effective removal of calcified midline thoracic disc herniations. We did not observe any postoperative neurological worsening, onset of spinal instability, or other adverse events.

Augmented Endoscopic Images Overlaying Shape Changes in Bone Cutting Procedures

In microendoscopic discectomy for spinal disorders, bone cutting procedures are performed in tight spaces while observing a small portion of the target structures. Although optical tracking systems are able to measure the tip of the surgical tool during surgery, the poor shape information available during surgery makes accurate cutting difficult, even if preoperative computed tomography and magnetic resonance images are used for reference. Shape estimation and visualization of the target structures are essential for accurate cutting. However, time-varying shape changes during cutting procedures are still challenging issues for intraoperative navigation. This paper introduces a concept of endoscopic image augmentation that overlays shape changes to support bone cutting procedures. This framework handles the history of the location of the measured drill tip as a volume label and visualizes the remains to be cut overlaid on the endoscopic image in real time. A cutting experiment was performed with volunteers, and the feasibility of this concept was examined using a clinical navigation system. The efficacy of the cutting aid was evaluated with respect to the shape similarity, total moved distance of a cutting tool, and required cutting time. The results of the experiments showed that cutting performance was significantly improved by the proposed framework.

Minimally Invasive Spinal Surgery with Intraoperative Image-Guided Navigation

We present our perioperative minimally invasive spine surgery technique using intraoperative computed tomography image-guided navigation for the treatment of various lumbar spine pathologies. We present an illustrative case of a patient undergoing minimally invasive percutaneous posterior spinal fusion assisted by the O-arm system with navigation. We discuss the literature and the advantages of the technique over fluoroscopic imaging methods: lower occupational radiation exposure for operative room personnel, reduced need for postoperative imaging, and decreased revision rates. Most importantly, we demonstrate that use of intraoperative cone beam CT image-guided navigation has been reported to increase accuracy.