Navigation Surgery Research Articles

Ultrasound-based navigation for open liver surgery using active liver tracking.

Despite extensive preoperative imaging, intraoperative localization of liver lesions after systemic treatment can be challenging. Therefore, an image-guided navigation setup is explored that links preoperative diagnostic scans and 3D models to intraoperative ultrasound (US), enabling overlay of detailed diagnostic images on intraoperative US. Aim of this study is to assess the workflow and accuracy of such a navigation system which compensates for liver motion. Electromagnetic (EM) tracking was used for organ tracking and movement of the transducer. After laparotomy, a sensor was attached to the liver surface while the EM-tracked US transducer enabled image acquisition and landmark digitization. Landmarks surrounding the lesion were selected during patient-specific preoperative 3D planning and identified for registration during surgery. Endpoints were accuracy and additional times of the investigative steps. Accuracy was computed at the center of the target lesion. In total, 22 navigated procedures were performed. Navigation provided useful visualization of preoperative 3D models and their overlay on US imaging. Landmark-based registration resulted in a mean fiducial registration error of 10.3 ± 4.3mm, and a mean target registration error of 8.5 ± 4.2mm. Navigation was available after an average of 12.7min. We developed a navigation method combining ultrasound with active liver tracking for organ motion compensation, with an accuracy below 10mm. Fixation of the liver sensor near the target lesion compensates for local movement and contributes to improved reliability during navigation. This represents an important step forward in providing surgical navigation throughout the procedure. This study is registered in the Netherlands Trial Register (number NL7951).

Sentinel node navigation surgery in cervical cancer: a systematic review and metaanalysis.

Sentinel node navigation surgery (SNNS) is used in clinical practice for the treatment of cervical cancer. This study aimed to elucidate the appropriate sentinel lymph node (SLN) mapping method and assess the safety and benefits of SNNS. We searched the PubMed, Ichushi, and Cochrane Library databases for randomized controlled trials (RCT) and studies on SLN in cervical cancer from January 2012 to December 2020. Two authors independently assessed study quality and extracted data. We quantitatively analyzed the detection rate, sensitivity/specificity, and complications and reviewed information, including the survival data of SLN biopsy (SLNB) without pelvic lymphadenectomy (PLND). The detection rate of SLN mapping in the unilateral pelvis was median 95.7% and 100% and in the bilateral pelvis was median 80.4% and 90% for technetium-99m (Tc) with/without blue dye (Tc w/wo BD) and indocyanine green (ICG) alone, respectively. The sensitivity and specificity of each tracer were high; the area under the curve of each tracer was 0.988 (Tc w/wo BD), 0.931 (BD w/wo Tc), 0.966 (ICG), and 0.977 (carbon nanoparticle). Morbidities including lymphedema, neurological symptoms and blood loss were associated with PLND. One RCT and five studies all showed SNNS without systematic PLND does not impair recurrence or survival in early-stage cervical cancer with a tumor size ≤ 2-4cm. Both Tc w/wo BD and ICG are appropriate SLN tracers. SNNS can reduce the morbidities associated with PLND without affecting disease progression in early-stage cervical cancer.

A 3D Image Registration Method for Laparoscopic Liver Surgery Navigation

At present, laparoscopic augmented reality (AR) navigation has been applied to minimally invasive abdominal surgery, which can help doctors to see the location of blood vessels and tumors in organs, so as to perform precise surgery operations. Image registration is the process of optimally mapping one or more images to the target image, and it is also the core of laparoscopic AR navigation. The key is how to shorten the registration time and optimize the registration accuracy. We have studied the three-dimensional (3D) image registration technology in laparoscopic liver surgery navigation and proposed a new registration method combining rough registration and fine registration. First, the adaptive fireworks algorithm (AFWA) is applied to rough registration, and then the optimized iterative closest point (ICP) algorithm is applied to fine registration. We proposed a method that is validated by the computed tomography (CT) dataset 3D-IRCADb-01. Experimental results show that our method is superior to other registration methods based on stochastic optimization algorithms in terms of registration time and accuracy.

Real-time automatic tumor segmentation for ultrasound-guided breast-conserving surgery navigation.

Ultrasound-based navigation is a promising method in breast-conserving surgery, but tumor contouring often requires a radiologist at the time of surgery. Our goal is to develop a real-time automatic neural network-based tumor contouring process for intraoperative guidance. Segmentation accuracy is evaluated by both pixel-based metrics and expert visual rating. This retrospective study includes 7318 intraoperative ultrasound images acquired from 33 breast cancer patients, randomly split between 80:20 for training and testing. We implement a u-net architecture to label each pixel on ultrasound images as either tumor or healthy breast tissue. Quantitative metrics are calculated to evaluate the model's accuracy. Contour quality and usability are also assessed by fellowship-trained breast radiologists and surgical oncologists. Additionally, the viability of using our u-net model in an existing surgical navigation system is evaluated by measuring the segmentation frame rate. The mean dice similarity coefficient of our u-net model is 0.78, with an area under the receiver-operating characteristics curve of 0.94, sensitivity of 0.95, and specificity of 0.67. Expert visual ratings are positive, with 93% of responses rating tumor contour quality at or above 7/10, and 75% of responses rating contour quality at or above 8/10. Real-time tumor segmentation achieved a frame rate of 16 frames-per-second, sufficient for clinical use. Neural networks trained with intraoperative ultrasound images provide consistent tumor segmentations that are well received by clinicians. These findings suggest that neural networks are a promising adjunct to alleviate radiologist workload as well as improving efficiency in breast-conserving surgery navigation systems.

ПРЕИМУЩЕСТВА И НЕДОСТАТКИ НАВИГАЦИОННОЙ ХИРУРГИИ ПРИ ДЕНТАЛЬНОЙ ИМПЛАНТАЦИИ

This review highlights the advantages and disadvantages of various methods of navigation surgery during dental implantation surgery, which contribute to the precise surgical placement of implants. This technique can be divided into: dynamic (DN) and static navigation (SN), and static navigation can be divided into full (FN) (full surgical protocol) and pilot surgery (PS). Dynamic navigation (DN) includes drilling-driven approaches and non-computing-driven approaches. In dynamic navigation, bone formation and implant placement are fully monitored using special software; while static navigation refers to the use of static navigation patterns. The complete surgical protocol associated with flapless surgery and milling cutter guides has demonstrated the highest accuracy, followed by pilot surgery, which can provide comparable results, while the installation of implants without a computer provides the least accuracy when transferring the implant positioning from preoperative planning to the patient. In addition, the surgical stage without folding the flap is associated with a reduction in pain, less consumption of painkillers, less swelling, shorter time in the chair and a reduced risk of bleeding while achieving greater patient satisfaction. However, other methods, such as non-computer implantation procedures, require more surgical experience to overcome their limitations. There is still little evidence to support dynamic surgery, and further research is needed.

Review and Future/Potential Application of Mixed Reality Technology in Orthopaedic Oncology.

In orthopaedic oncology, surgical planning and intraoperative execution errors may result in positive tumor resection margins that increase the risk of local recurrence and adversely affect patients’ survival. Computer navigation and 3D-printed resection guides have been reported to address surgical inaccuracy by replicating the surgical plans in complex cases. However, limitations include surgeons’ attention shift from the operative field to view the navigation monitor and expensive navigation facilities in computer navigation surgery. Practical concerns are lacking real-time visual feedback of preoperative images and the lead-time in manufacturing 3D-printed objects. Mixed Reality (MR) is a technology of merging real and virtual worlds to produce new environments with enhanced visualizations, where physical and digital objects coexist and allow users to interact with both in real-time. The unique MR features of enhanced medical images visualization and interaction with holograms allow surgeons real-time and on-demand medical information and remote assistance in their immediate working environment. Early application of MR technology has been reported in surgical procedures. Its role is unclear in orthopaedic oncology. This review aims to provide orthopaedic tumor surgeons with up-to-date knowledge of the emerging MR technology. The paper presents its essential features and clinical workflow, reviews the current literature and potential clinical applications, and discusses the limitations and future development in orthopaedic oncology. The emerging MR technology adds a new dimension to digital assistive tools with a more accessible and less costly alternative in orthopaedic oncology. The MR head-mounted display and hand-free control may achieve clinical point-of-care inside or outside the operating room and improve service efficiency and patient safety. However, lacking an accurate hologram-to-patient matching, an MR platform dedicated to orthopaedic oncology, and clinical results may hinder its wide adoption. Industry-academic partnerships are essential to advance the technology with its clinical role determined through future clinical studies.

Predictive factors for false negatives following sentinel lymph node biopsy in early oral cavity cancer

Prophylactic elective neck dissection (ND) with navigation surgery using radioisotope-based sentinel lymph node biopsy (SLNB) is non-inferior to elective ND in terms of survival but has an advantage in postoperative functional disability. We conducted a subgroup analysis to identify predictive factors for false-negative (FN)-SLNB in patients with early oral cavity cancer. This study is a supplementary analysis using the dataset of a previously reported randomized clinical trial on SLN navigation surgery for oral cancers. This study investigated the association of clinical and SLN-related factors with false-negative cases in the SLNB group. From 2011 to 2016, 275 patients were enrolled and randomly assigned to the ND and SLNB study groups, with 134 patients assigned to the SLNB group. In the SLNB group, seven cases with negative SLNs and neck recurrences were judged as FN-SLNBs according to the general definition. The number of detected SLNs with and without adjusting for the propensity score was significantly associated with FNs in the logistic analysis. FN-SLNB was associated with the number of identified SLNs, suggesting the need for careful postoperative monitoring for neck recurrence in patients with one or two identified SLNs after acquiring sufficient experience in the identification technique.

190: ENDOSCOPIC SUBMUCOSAL DISSECTION (ESD) AND ROBOTIC SENTINEL NODE NAVIGATION SURGERY FOR EARLY GASTRIC CANCER: FIRST EXPERIENCE AND PRELIMINARY RESULTS

Abstract Background and aim Early gastric cancer (EGC) is defined as a cancer limited to mucosa (T1a) and submucosa (T1b). The 5-year survival rates are respectively 96% and 83% for T1a and T1b. Despite endoscopic submucosal dissection (ESD) is considered the standard treatment for EGC, literature reports a quite considerable rate of lymph-node metastasis (2% to 18%). Combined surgical-endoscopic treatment can achieve accurate resection of EGC, solving the problem of lymphadenectomy which cannot be performed endoscopically. Near infrared (NIR) fluorescence imaging with indocyanine green (ICG) was recently introduced for lymphatic mapping in several tumors. The aim of the study is to evaluate the feasibility and safety of ESD in combination with robotic ICG guided sentinel node navigation surgery (SNNS). Methods ICG was endoscopically injected intraoperatively into the submucosal layer around the tumor. Intraoperative NIR imaging with ICG was carried out with a near-infrared camera system built into the robotic platform. The first lymph node which had taken up ICG appeared as a green spot and was identified as the sentinel node (SN). SN was then sent for extemporaneous histopathological examination. When ICG fluorescence extended to the second nodal stations a ICG guided robotic basin lymphadenectomy was performed. Basin lymph nodes were sent for definitive histopathological analysis. If no tumoral cells were identified in the SN, an ESD with standard technique was conducted. If the SN pathological examination revealed tumoral cells, a robotic radical resection and D2 lymphadenectomy was completed. Results Seven ESDs with SNNS and basin lymphadenectomy basin were performed. No gastric perforations or other intraoperative complications were registered. Mean operative time was 148.6 minutes. All the procedures histologically resulted in complete excisions. No lymph nodes metastasis was demonstrated in either the SN or the basin lymph nodes. A mean of 12 lymph-nodes was collected. Mean hospitalization time was 2.8 days. Conclusion In our preliminary experience, combined ESD and SNNS could be recommended as a safe and effective treatment for EGC in patients with potential risk of LN metastasis or in patients with multiple comorbidity in order to avoid more invasive organ resections.

Percutaneous posterior lumbar interbody fusion using optical topographic navigation: Operative technique

Despite the availability of navigation systems in spine surgery for over two decades, uptake into routine clinical practice has been limited in large part due to disruption of workflow with associated increased operative time. Optical topographical navigation for spine surgery permits safe and accurate placement of pedicle screws without any exposure to intraoperative ionizing radiation and may in fact improve workflow owing to a rapid registration time. Here we describe a novel application of 7D navigation system in a minimally invasive approach for posterior lumbar inter-body fusion (PLIF) with percutaneous screw placement.To our knowledge, this is the first publishable paper discussing the application of optical topographic navigation in minimally invasive PLIF. In our experience this technique was efficient, reliable and requires systematic study to evaluate long-term outcomes and potential benefits and pitfalls.

Laparoscopic sentinel node navigation surgery in gastric cancer to reduce surgical radicality

Laparoscopic sentinel node navigation surgery in gastric cancer to reduce surgical radicality

Comparison of Implant Placement Accuracy in Healed and Fresh Extraction Sockets between Static and Dynamic Computer-Assisted Implant Surgery Navigation Systems: A Model-Based Evaluation.

The aim of this model-base study was to compare the accuracy of implant placement between static and dynamic computer-assisted implant surgery (CAIS) systems in a fresh extraction socket and healed ridge. A randomized in vitro study was conducted. Twenty 3D-printed maxillary models and 80 implants were used. One experienced researcher placed the implants using either the static navigation or dynamic navigation system. Accuracy was measured by overlaying the real position in the postoperative CBCT on the virtual presurgical placement of the implant in a CBCT image. Descriptive and bivariate analyses of the data were performed. In the fresh sockets, the mean deviation was 1.24 ± 0.26 mm (entry point), 1.69 ± 0.34 mm (apical point), and 3.44 ± 1.06° (angle discrepancy) in the static CAIS group, and 0.60 ± 0.29 mm, 0.78 ± 0.33 mm, and 2.47 ± 1.09° in the dynamic CIAS group, respectively. In the healed ridge, the mean deviation was 1.09 ± 0.17 mm and 1.40 ± 0.30 mm, and 2.12 ± 1.11° in the static CAIS group, and 0.80 ± 0.29 mm, 0.98 ± 0.37 mm, and 1.69 ± 0.76° in the dynamic CIAS group, respectively. Compared with the static CAIS system, the dynamic CAIS system resulted in significantly lower entry and apical errors in both fresh sockets and healed ridges. Differences in bone morphology therefore seem to have little effect on accuracy in the dynamic CAIS group.

Artificial Intelligence-Based Total Mesorectal Excision Plane Navigation in Laparoscopic Colorectal Surgery.

Total mesorectal excision is the standard surgical procedure for rectal cancer because it is associated with low local recurrence rates. To the best of our knowledge, this is the first study to use an image-guided navigation system with total mesorectal excision. The impact of innovation is the development of a deep learning-based image-guided navigation system for areolar tissue in the total mesorectal excision plane. Such a system might be helpful to surgeons because areolar tissue can be used as a landmark for the appropriate dissection plane. This was a single-center experimental feasibility study involving 32 randomly selected patients who had undergone laparoscopic left-sided colorectal resection between 2015 and 2019. Deep learning-based semantic segmentation of areolar tissue in the total mesorectal excision plane was performed. Intraoperative images capturing the total mesorectal excision scene extracted from left colorectal laparoscopic resection videos were used as training data for the deep learning model. Six hundred annotation images were created from 32 videos, with 528 images in the training and 72 images in the test data sets. The experimental feasibility study was conducted at the Department of Colorectal Surgery, National Cancer Center Hospital East, Chiba, Japan. Dice coefficient was used to evaluate semantic segmentation accuracy for areolar tissue. The developed semantic segmentation model helped locate and highlight the areolar tissue area in the total mesorectal excision plane. The accuracy and generalization performance of deep learning models depend mainly on the quantity and quality of the training data. This study had only 600 images; thus, more images for training are necessary to improve the recognition accuracy. We successfully developed a total mesorectal excision plane image-guided navigation system based on an areolar tissue segmentation approach with high accuracy. This may aid surgeons in recognizing the total mesorectal excision plane for dissection.

Surface Navigation and the Influence of Navigation on MIS Surgery.

Study Design:Literature review.Objectives:To review the evidence for surface-based navigation in minimally-invasive spine surgery (MIS), provide an outline for its workflow, and present a wide range of MIS case examples in which surface-based navigation may be advantageous.Methods:A comprehensive review of the literature and compilation of findings related to surface-based navigation in MIS was performed. Workflow and case examples utilizing surface-based navigation were described.Results:The nascent literature regarding surface-based intraoperative navigation (ION) in spine surgery is encouraging and initial studies have shown that surface-based navigation can allow for accurate pedicle screw placement and decreased operative time, fluoroscopy time, and radiation exposure when compared to traditional fluoroscopic imaging. Surface-based navigation may be particularly useful in MIS cervical and lumbar decompressions and MIS lumbar instrumentation cases.Conclusions:Overall, it is possible that surface-based ION will become a mainstay in the armamentarium of enabling technologies utilized by minimally-invasive spine surgeons, but further studies are needed assessing its accuracy, complications, and cost-effectiveness.

Laparoscopic Sentinel Node Navigation Surgery for Stomach Preservation in Patients With Early Gastric Cancer: A Randomized Clinical Trial.

PURPOSETo compare postoperative complications, long-term survival, and quality of life (QOL) after laparoscopic sentinel node navigation surgery (LSNNS) and laparoscopic standard gastrectomy (LSG).METHODSFive hundred eighty patients with preoperatively diagnosed stage IA gastric adenocarcinoma (≤ 3 cm) were assigned to undergo either LSG or LSNNS. Observers were not blinded to patient grouping. The primary outcome was 3-year disease-free survival (3y-DFS). Secondary outcomes included postoperative complications, QOL, 3-year disease-specific survival (3y-DSS), and 3-year overall survival (3y-OS).RESULTSIn total, 527 patients were included in the modified intention-to-treat analysis population for the primary outcome (LSG, 269; LSNNS, 258). Stomach-preserving surgery was performed in 210 patients (81%) in the LSNNS group. During the median follow-up duration, the 3y-DFS rates in the LSG and LSNNS groups were 95.5% and 91.8%, respectively (difference: 3.7%; 95% CI, –0.6 to 8.1). Three patients with recurrence and five with metachronous gastric cancer in the LSNNS group underwent standard surgery. Two patients with distant metastasis in both groups were treated with palliative chemotherapy. The 3y-DSS and 3y-OS rates in the LSG and LSNNS groups were 99.5% and 99.1% (P = .59) and 99.2% and 97.6% (P = .17), respectively. Postoperative complications occurred in 19.0% of the LSG group and 15.5% of the LSNNS group (P = .294). The LSNNS group showed better physical function (P = .015), less symptoms (P < .001), and improved nutrition than the LSG group.CONCLUSIONLSNNS did not show noninferiority to LSG for 3y-DFS, with a 5% margin. However, the 3y-DSS and 3y-OS were not different after rescue surgery in cases of recurrence/metachronous gastric cancer, and LSNNS had better long-term QOL and nutrition than LSG.

Accurate Mandible Reconstruction by Mixed Reality, 3D Printing, and Robotic-Assisted Navigation Integration.

:Mandibular reconstruction is one of the most complex procedures concerning the patient’s postoperative facial shape and occlusion condition. In this study, the authors integrated mixed reality, three-dimensional (3D) printing, and robotic-assisted navigation technology to complete the mandibular reconstruction in a novel and more accurate way. Mixed reality can visualize the significant anatomical structures of the operative area, but only be used in simulated operation by now. Three-dimensional printing surgical guide plate makes it easy to separate tissue, while imprecision often occurs due to the potential of displacement and deformation. In recent years, most robotic-assisted navigation surgery technology can only achieve precise position by 2D view on the screen but not realistic 3D navigation. in this study, the integrated 3 technologies were used in mandibular reconstruction. Preoperative imaging examination was performed, and the data were imported into the digital workstation before operation. First, the original data was edited and optimized to reconstruct the digital model and formulate the surgical plan. Then MR was used to output the visualized project and matched the 3D reconstruction model in reality. The 3D plate was printed for surgical guidance. Last, robotic-assisted navigation was used to guide and position the vascularized fibula autograft and the immediate dental implantation. In conclusion, the authors integrated the 3 technologies and constructed a new digital surgical procedure to improve surgical accuracy and simplify the procedure comparing with traditional surgery.

Phantom-based prospective analysis of the accuracy of photo registration technology in electromagnetic navigation of the frontal skull base.

This prospective study compared the accuracy of two different company-specific registration methods (Fiagon GmbH, Hennigsdorf, Germany) in the electromagnetic navigation of the frontal skull base. A newly developed photo registration technology (Fiagon tracey©) promises an increase in accuracy and user-friendliness, but there is no phantom-based prospective study comparing the new method with the classic approach of tactile surface registration. A phantom skull was prepared with 27 markers in the sagittal, axial and coronary planes, and their reference coordinates were determined using a navigational CT (low dose, slice 0.6 mm). Subsequently, 20 runs of automatic photo registration and tactile surface registration were carried out, and the resulting marker coordinates were compared with the reference coordinates. The target registration error (TRE) of the 27 markers was assessed and compared between the two methods using a 2-factor ANOVA with repeated measures. The mean TRE using surface registration was 1.97 mm ± 0.57, while the mean TRE of the automatic photo registration was 1.54 mm ± 0.24 (p < 0.001). In a subgroup analysis limited to markers in anatomical regions of clinical relevance in terms of paranasal sinus surgery, the mean TRE for the photo registration procedure can even be reduced to 1.29 mm (± 0.43) compared to tactile registration (1.80 mm; ±0.50; p=0.01). Photo registration is a promising new technology in the field of electromagnetic navigation in paranasal sinus surgery. This prospective phantom-based study showed that the photo registration method achieves a significantly lower target registration error (1.29 mm) compared to the surface-based tactile registration procedure (1.80 mm).

Intelligent SERS Navigation System Guiding Brain Tumor Surgery by Intraoperatively Delineating the Metabolic Acidosis (Adv. Sci. 7/2022)

Surgery Navigation System Surgeons face challenges in defining brain tumor margins due to its infiltrative nature. In article number 2104935 by Ying Mao, Jinhua Yu, Xiao-Yong Zhang, Cong Li, and co-workers, an intelligent SERS navigation system is developed to intraoperatively guide tumor resection by delineating the metabolic acidosis without the administration of exogenous probes. Considering the correlation between tissue acidity and malignancy, this system holds the promise in improving surgical prognosis by precisely defining tumor infiltrative regions.

Intraoperative Navigation in Plastic Surgery with Augmented Reality: A Preclinical Validation Study.

Augmented reality allows users to visualize and interact with digital images including three-dimensional holograms in the real world. This technology may have value intraoperatively by improving surgical decision-making and precision but relies on the ability to accurately align a hologram to a patient. This study aims to quantify the accuracy with which a hologram of soft tissue can be aligned to a patient and used to guide intervention. A mannequin's face was marked in a standardized fashion with 14 incision patterns in red and nine reference points in blue. A three-dimensional photograph was then taken, converted into a hologram, and uploaded to HoloLens (Verto Studio LLC, San Diego, Calif.), a wearable augmented reality device. The red markings were then erased, leaving only the blue points. The hologram was then viewed through the HoloLens in augmented reality and aligned onto the mannequin. The user then traced the overlaid red markings present on the hologram. Three-dimensional photographs of the newly marked mannequin were then taken and compared with the baseline three-dimensional photographs of the mannequin for accuracy of the red markings. This process was repeated for 15 trials (n = 15). The accuracy of the augmented reality-guided intervention, when considering all trials, was 1.35 ± 0.24 mm. Markings that were positioned laterally on the face were significantly more difficult to reproduce than those centered around the facial midline. Holographic markings can be accurately translated onto a mannequin with an average error of less than 1.4 mm. These data support the notion that augmented reality navigation may be practical and reliable for clinical integration in plastic surgery.

Near-infrared fluorescence imaging with indocyanine green to assess the blood supply of the reconstructed gastric conduit to reduce anastomotic leakage after esophagectomy: a literature review.

The blood supply of the right gastroepiploic artery after esophagectomy with gastric tube reconstruction is essential for avoiding anastomotic leakage. Near-infrared fluorescence (NIRF) imaging with indocyanine green is widely used to assess the blood supply because it can visualize it in real-time during navigation surgery. However, there is no established protocol for this modality. One reason for this lack of protocol is that NIRF provides subjective information. This study aimed to evaluate NIRF quantification. We conducted a literature review of risk factors for anastomotic leakage after esophagectomy, NIRF procedures, NIRF quantification, and new methods to compensate for NIRF limitations. Major methods for the quantification of NIRF include measuring the blood flow speed, visualization time, and fluorescence intensity. The cutoff value for the blood flow speed is 2.07cm/s, and that for the visualization time is 30-90s. Although the time-intensity curve provided patterns of change in the blood flow, it did not show an association with anastomotic leakage. However, to compensate for the limitations of NIRF, new devices have been reported that can assess tissue oxygenation perfusion, organ hemoglobin concentration, and microcirculation.

Augmented Reality Spine Surgery Navigation: Increasing Pedicle Screw Insertion Accuracy for Both Open and Minimally Invasive Spine Surgeries.

Collectively, seven cadavers were instrumented with 124 thoracolumbar pedicle screws using VisAR augmented reality/guidance. Sixty-five screws were inserted into four donors using open dissection spine surgery. Fifty-nine screws were positioned in three donors with a minimally invasive spine surgery (MISS) procedure. For both open and MISS, VisAR was used exclusively for pedicle screw navigation. The objective of this study was to determine the accuracy of pedicle screw placement using VisAR for open spine and MISS procedures. Pedicle screw placement can be challenging depending on anatomical location and a surgeon's experience. AR may minimize fluoroscopy use and speed screw insertion. Prior to computed tomography (CT) a series of four image visible April Tag optical fiducials were attached to the backs' of the donors. Resulting images were used preoperatively for planned virtual pedicle screw pathways including entry point, trajectory, and depth. The study link was encrypted on a quick response (QR) code, printed, and viewed in the operating room (OR) by the surgeon using VisAR (HoloLens 2 headset). Viewing the code wirelessly uploads and launches the study, converting the DICOM data to holographic images which register to the fiducials on the donor's back. The annotated pathways for each pedicle were called up by voice command and the surgeon positioned each screw by aligning with the virtual guidance hologram. Overall, 124 pedicle screws were inserted with VisAR navigation with 96% accuracy (Gertzbein-Robbins grades A and B). The combined angle of error was 2.4° and the distance error was 1.9 mm. Augmented reality is a highly accurate, emerging technology for navigating both open and minimally invasive spine surgery techniques with off-the-shelf headset hardware. N/A.