Intraoperative Surgical Navigation Research Articles

Noctopus: a novel device and method for patient registration and navigation in image-guided cranial surgery.

A patient registration and real-time surgical navigation system and a novel device and method (Noctopus) is presented. With any tracking system technology and a patient/target-specific registration marker configuration, submillimetric target registration error (TRE), high-precise application accuracy for single or multiple anatomical targets in image-guided neurosurgery or ENT surgery is realized. The system utilizes the advantages of marker-based registration technique and allows to perform automatized patient registration using on the device attached and with patient scanned four fiducial markers. The best possible sensor/marker positions around the patient's head are determined for single or multiple region(s) of interest (target/s) in the anatomy. Once brought at the predetermined positions the device can be operated with any tracking system for registration purposes. Targeting accuracy was evaluated quantitatively at various target positions on a phantom skull. The target registration error (TRE) was measured on individual targets using an electromagnetic tracking system. The overall averaged TRE was 0.22 ± 0.08 mm for intraoperative measurements. An automatized patient registration system using optimized patient-/target-specific marker configurations is proposed. High-precision and user-error-free intraoperative surgical navigation with minimum number of registration markers and sensors is realized. The targeting accuracy is significantly improved in minimally invasive neurosurgical and ENT interventions.

Evolution of the meta-neurosurgeon: A systematic review of the current technical capabilities, limitations, and applications of augmented reality in neurosurgery.

Augmented reality (AR) applications in neurosurgery have expanded over the past decade with the introduction of headset-based platforms. Many studies have focused on either preoperative planning to tailor the approach to the patient's anatomy and pathology or intraoperative surgical navigation, primarily realized as AR navigation through microscope oculars. Additional efforts have been made to validate AR in trainee and patient education and to investigate novel surgical approaches. Our objective was to provide a systematic overview of AR in neurosurgery, provide current limitations of this technology, as well as highlight several applications of AR in neurosurgery. We performed a literature search in PubMed/Medline to identify papers that addressed the use of AR in neurosurgery. The authors screened three hundred and seventy-five papers, and 57 papers were selected, analyzed, and included in this systematic review. AR has made significant inroads in neurosurgery, particularly in neuronavigation. In spinal neurosurgery, this primarily has been used for pedicle screw placement. AR-based neuronavigation also has significant applications in cranial neurosurgery, including neurovascular, neurosurgical oncology, and skull base neurosurgery. Other potential applications include operating room streamlining, trainee and patient education, and telecommunications. AR has already made a significant impact in neurosurgery in the above domains and has the potential to be a paradigm-altering technology. Future development in AR should focus on both validating these applications and extending the role of AR.

Statistical segmentation model for accurate electrode positioning in Parkinson's deep brain stimulation based on clinical low-resolution image data and electrophysiology.

Deep Brain Stimulation (DBS), applying chronic electrical stimulation of subcortical structures, is a clinical intervention applied in major neurologic disorders. In order to achieve a good clinical effect, accurate electrode placement is necessary. The primary localisation is typically based on presurgical MRI imaging, often followed by intra-operative electrophysiology recording to increase the accuracy and to compensate for brain shift, especially in cases where the surgical target is small, and there is low contrast: e.g., in Parkinson's disease (PD) and in its common target, the subthalamic nucleus (STN). We propose a novel, fully automatic method for intra-operative surgical navigation. First, the surgical target is segmented in presurgical MRI images using a statistical shape-intensity model. Next, automated alignment with intra-operatively recorded microelectrode recordings is performed using a probabilistic model of STN electrophysiology. We apply the method to a dataset of 120 PD patients with clinical T2 1.5T images, of which 48 also had available microelectrode recordings (MER). The proposed segmentation method achieved STN segmentation accuracy around dice = 0.60 compared to manual segmentation. This is comparable to the state-of-the-art on low-resolution clinical MRI data. When combined with electrophysiology-based alignment, we achieved an accuracy of 0.85 for correctly including recording sites of STN-labelled MERs in the final STN volume. The proposed method combines image-based segmentation of the subthalamic nucleus with microelectrode recordings to estimate their mutual location during the surgery in a fully automated process. Apart from its potential use in clinical targeting, the method can be used to map electrophysiological properties to specific parts of the basal ganglia structures and their vicinity.

INTRAOPERATIVE SURGICAL NAVIGATION BASED ON LASER SCANNER FOR IMAGE-GUIDED ORAL AND MAXILLOFACIAL SURGERY

In oral and maxillofacial surgery, computer-assisted navigation technologies have been widely used to achieve intraoperative positioning. The traditional methods mainly rely on the experience of doctors and the difference between the locations of key points in the surgical area and the preoperative planning, which have certain limitations. In this paper, a new intraoperative surgical navigation framework based on mobile laser scanner is proposed, which ensures that surgery is performed accurately according to the preoperative planning. The framework mainly includes two parts. First, the real-time surface reconstruction of the anatomy should be realized during the operation. Second, the acquired image is matched to the planned image in real time. Although the most common method of surface reconstruction is to render the volume directly from raw data or render the surface from the segmented data using computed tomography/magnetic resonance (CT/MR) data, this method is too complicated for performing the real-time operation during surgery. Furthermore, a new surface registration technique is proposed for image-guided oral and maxillofacial surgery based on the point sets. To improve the registration accuracy and robustness, the point sets are modeled by Mixed Student’s t-Distribution model. In the experiments, the point sets of CT data are from 10 patients with craniomaxillofacial diseases and the surface point set is from the LRS. The TRE of 10 data was less than 1[Formula: see text]mm. Compared with the paired-point registration method and Iterative Closest Point algorithm, the results demonstrated better performance of the proposed method, the surgical situation can be displayed in real time during the surgical process, and any differences from the surgical plan can also be reflected.

Multimodality Imaging for 3D Printing and Surgical Rehearsal in Complex Spine Surgery.

Surgery is the mainstay treatment of symptomatic spinal tumors. It aids in restoring functionality, managing pain and tumor growth, and improving overall quality of life. Over the past decade, advancements in medical imaging techniques combined with the use of three-dimensional (3D) printing technology have enabled improvements in the surgical management of spine tumors by significantly increasing the precision, accuracy, and safety of the surgical procedures. For complex spine surgical cases, the use of multimodality imaging is necessary to fully visualize the extent of disease, including both soft-tissue and bone involvement. Integrating the information provided by these examinations in a cohesive manner to facilitate surgical planning can be challenging, particularly when multiple surgical specialties work in concert. The digital 3-dimensional (3D) model or 3D rendering and the 3D printed model created from imaging examinations such as CT and MRI not only facilitate surgical planning but also allow the placement of virtual and physical surgical or osteotomy planes, further enhancing surgical planning and rehearsal. The authors provide practical information about the 3D printing workflow, from image acquisition to postprocessing of a 3D printed model, as well as optimal material selection and incorporation of quality management systems, to help surgeons utilize 3D printing for surgical planning. The authors also highlight the process of surgical rehearsal, how to prescribe digital osteotomy planes, and integration with intraoperative surgical navigation systems through a case-based discussion. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Intratumor injected gold molecular clusters for NIR-II imaging and cancer therapy

Surgical resections of solid tumors guided by visual inspection of tumor margins have been performed for over a century to treat cancer. Near-infrared (NIR) fluorescence labeling/imaging of tumor in the NIR-I (800 to 900 nm) range with systemically administrated fluorophore/tumor-targeting antibody conjugates have been introduced to improve tumor margin delineation, tumor removal accuracy, and patient survival. Here, we show Au25 molecular clusters functionalized with phosphorylcholine ligands (AuPC, ~2 nm in size) as a preclinical intratumorally injectable agent for NIR-II/SWIR (1,000 to 3,000 nm) fluorescence imaging-guided tumor resection. The AuPC clusters were found to be uniformly distributed in the 4T1 murine breast cancer tumor upon intratumor (i.t.) injection. The phosphocholine coating afforded highly stealth clusters, allowing a high percentage of AuPC to fill the tumor interstitial fluid space homogeneously. Intra-operative surgical navigation guided by imaging of the NIR-II fluorescence of AuPC allowed for complete and non-excessive tumor resection. The AuPC in tumors were also employed as a photothermal therapy (PTT) agent to uniformly heat up and eradicate tumors. Further, we performed in vivo NIR-IIb (1,500 to 1,700 nm) molecular imaging of the treated tumor using a quantum dot-Annexin V (QD-P3-Anx V) conjugate, revealing cancer cell apoptosis following PTT. The therapeutic functionalities of AuPC clusters combined with rapid renal excretion, high biocompatibility, and safety make them promising for clinical translation.

The role of imaging in extremity sarcoma surgery.

The surgical management of extremity bone and soft tissue sarcomas has evolved significantly over the last 50years. The introduction and refinement of high-resolution cross-sectional imaging has allowed accurate assessment of anatomy and tumor extent, and in the current era more than 90% of patients can successfully undergo limb-salvage surgery. Advances in imaging have also revolutionized the clinician's ability to assess treatment response, detect metastatic disease, and perform intraoperative surgical navigation. This review summarizes the broad and essential role radiology plays in caring for sarcoma patients from diagnosis to post-treatment surveillance. Present evidence-based imaging paradigms are highlighted along with key future directions.

Development of an augmented reality guidance system for head and neck cancer resection.

The use of head-mounted augmented reality (AR) for surgeries has grown rapidly in recent years. AR aids in intraoperative surgical navigation through overlaying three-dimensional (3D) holographic reconstructions of medical data. However, performing AR surgeries on complex areas such as the head and neck region poses challenges in terms of accuracy and speed. This study explores the feasibility of an AR guidance system for resections of positive tumour margins in a cadaveric specimen. The authors present an intraoperative solution that enables surgeons to upload and visualize holographic reconstructions of resected cadaver tissues. The solution involves using a 3D scanner to capture detailed scans of the resected tissue, which are subsequently uploaded into our software. The software converts the scans of resected tissues into specimen holograms that are viewable through a head-mounted AR display. By re-aligning these holograms with cadavers with gestures or voice commands, surgeons can navigate the head and neck tumour site. This workflow can run concurrently with frozen section analysis. On average, the authors achieve an uploading time of 2.98min, visualization time of 1.05min, and re-alignment time of 4.39min, compared to the 20 to 30min typical for frozen section analysis. The authors achieve a mean re-alignment error of 3.1mm. The authors' software provides a foundation for new research and product development for using AR to navigate complex 3D anatomy in surgery.

TMIC-41. LATERAL VENTRICLE PROXIMITY OF GLIOBLASTOMA IS ASSOCIATED WITH LOCALIZED MALIGNANCY-PROMOTING MOLECULAR SIGNATURES IN IMAGE-GUIDED BIOPSIES

Abstract Glioblastoma (GBM) is the most devastating and common form of primary brain cancer in adults. Tumor location plays a significant role in patient prognosis; in particular, GBM tumors contacting the lateral ventricles (LVs) are more aggressive than LV-distal counterparts. This may be due to interaction of tumors with unique features of the LV microenvironment, including the cerebrospinal fluid (CSF) and neural progenitor cells (NPCs) of the subventricular zone. Despite LV contact having a role on tumor malignancy, studies using bulk tumor samples to identify molecular contributors to LV-contacting prognosis have been only moderately successful, in large part due to intratumoral heterogeneity. Here, we leverage intraoperative surgical navigation to collect matched biopsies of adult LV-contacting primary GBM at locations proximal (< 2 cm) and distal ( > 2 cm) from the LV. Matched samples were collected from ten patients with equal sex distribution and an age range of 46 to 81 years. RNA sequencing of biopsies revealed a localized transcriptional signature of gene expression in LV-proximal locations. These genes include those identified to be associated with GBM malignancy and upregulated in primary GBM cells by CSF exposure or co-culture with NPCs, such as SERPINA3, CD44, and CTSB, as well as many newly identified genes. Implicated biological pathways involved in this transcriptional signature involve inflammation, chemotaxis, Notch signaling, angiogenesis, integrin signaling, and more. The top 50 upregulated genes by LV-proximity of GBM were used to cluster patient transcriptomes from the TCGA GBM database and evaluate the contribution to patient outcome. This analysis revealed a cluster with significantly extended overall survival that displayed a general downregulation of LV-proximity genes. Ultimately, these studies provide evidence that regional tumoral analysis is essential in identifying molecular signatures associated with microenvironmental influence, and that LV-contacting GBM has regional gene expression changes in many genes associated with malignancy.

Intraoral Condylectomy with 3D-Printed Cutting Guide versus with Surgical Navigation: An Accuracy and Effectiveness Comparison.

This study compares the accuracy and effectiveness of our novel 3D-printed titanium cutting guides with intraoperative surgical navigation for performing intraoral condylectomy in patients with mandibular condylar osteochondroma (OC). A total of 21 patients with mandibular condylar OC underwent intraoral condylectomy with either 3D-printed cutting guides (cutting guide group) or with surgical navigation (navigation group). The condylectomy accuracy in the cutting guide group and navigation group was determined by analyzing the three-dimensional (3D) discrepancies between the postoperative computed tomography (CT) images and the preoperative virtual surgical plan (VSP). Moreover, the improvement of the mandibular symmetry in both groups was determined by evaluating the chin deviation, chin rotation and mandibular asymmetry index (AI). The superimposition of the condylar osteotomy area showed that the postoperative results were very close to the VSP in both groups. The mean 3D deviation and maximum 3D deviation between the planned condylectomy and the actual result were 1.20 ± 0.60 mm and 2.36 ± 0.51 mm in the cutting guide group, and 1.33 ± 0.76 mm and 4.27 ± 1.99 mm in the navigation group. Moreover, the facial symmetry was greatly improved in both groups, indicated by significantly decreased chin deviation, chin rotation and AI. In conclusion, our results show that both 3D-printed cutting-guide-assisted and surgical-navigation-assisted methods of intraoral condylectomy have high accuracy and efficiency, while using a cutting guide can generate a relatively higher surgical accuracy. Moreover, our cutting guides exhibit user-friendly features and simplicity, which represents a promising prospect in everyday clinical practice.

Better specificity and less ischemia: three-dimensional reconstruction is superior to routine computed tomography angiography in navigation of super-selective clamping robot-assisted laparoscopic partial nephrectomy.

Available technologies could be used to guide surgeons in controlling highly selective tumor-bearing arteries robot-assisted laparoscopic partial nephrectomy (RALPN). Patients undergoing RALPN (from September 2018 to January 2020) for intermediate-high complex renal tumor (R.E.N.A.L. score ≥7) who underwent abdominal computed tomography (CT) scan with angiography and hyper-accuracy 3-dimensional reconstruction (H3DR). All patients underwent high-resolution CT scan with angiography and H3DR with special software, based on which two kinds of highly selective arterial clamp protocols were made for each patient and analyzed independently by two urologists and two radiologists to confirm which renal arterial branch was supplying the tumor. We chose the optimized clamping protocol with the principle of the minimized ischemic regions. During the operation, meticulous microdissection and clip ligation of the specific vascular branch was guided by optimized protocol [H3DR or computed tomography angiography (CTA) reconstruction], according to the in vivo anatomy (identified by intraoperative ultrasound). Of 82 patients, the minimum-ischemic regions planning completed rate (MIRPCR) of preoperative planning with H3DR (90.2%) was higher than that with CTA (34.1%) (P<0.01). H3DR identified 78 high-order arteries (70.3%), whereas CTA identified 33 (29.7%) high-order arteries (P<0.001). H3DR detected a more optimal blocking option in 51 cases that were either missed (n=13) or misclassified by CTA (n=38). A total of 18 cases (56.3%) were converted to H3DR-guided occurred in CTA-guided surgery [5 (10.0%) occurred in group H3DR to CTA, P<0.01]. Moreover, in the CTA-guided group, the separation of renal hilum was avoided in 14 of 19 (73.7%) cases, whereas in the H3DR-guided group, it was avoided in 60 of 63 (95.3%) cases. For patients undergoing RALPN, H3DR-guided surgery compared with standard CTA-guided surgery has higher accuracy and feasibility in controlling arterial branches supplying the tumor and intraoperative surgical navigation. Additionally, it reduces the ischemic lesion area and simplifies vascular isolation steps, thus decreasing procedural difficulty.

The evolution of anatomical hepatectomy: Past, present, and future

The liver contains a complex structure of blood vessels and bile ducts, and the vascular structure is highly variable. The anatomical segmentation of the liver is still controversial, and the Couinaud segmentation method based on the portal vein is more widely used in clinical practice. The treatment of liver tumors and other lesions is closely related to the liver anatomy. The mechanism of liver tumor invasion and metastasis is complex, and it is currently believed that tumor invasion mainly spreads along the portal vein. Anatomic liver resection is an important surgical method for liver diseases, especially liver tumors. This article reviews the vascular structure of the liver, the development of anatomical hepatectomy, blood flow control, surgical planning, intraoperative navigation, minimally invasive surgery, and precise hepatectomy. Anatomic liver resection is a part of precision liver surgery, which is becoming increasingly more precise in terms of surgical evaluation, surgical planning, and surgical operation. New technologies will facilitate precision surgery with less trauma and greater benefits for patients. With the development and advancement of technology, image-based surgical planning and intraoperative surgical navigation will become more widely used in precision liver surgery.

3D Reconstruction of cellular images from microfabricated imagers using fully-adaptive deep neural networks

Millimeter-scale multi-cellular level imagers enable various applications, ranging from intraoperative surgical navigation to implantable sensors. However, the tradeoffs for miniaturization compromise resolution, making extracting 3D cell locations challenging—critical for tumor margin assessment and therapy monitoring. This work presents three machine-learning-based modules that extract spatial information from single image acquisitions using custom-made millimeter-scale imagers. The neural networks were trained on synthetically-generated (using Perlin noise) cell images. The first network is a convolutional neural network estimating the depth of a single layer of cells, the second is a deblurring module correcting for the point spread function (PSF). The final module extracts spatial information from a single image acquisition of a 3D specimen and reconstructs cross-sections, by providing a layered “map” of cell locations. The maximum depth error of the first module is 100 µm, with 87% test accuracy. The second module’s PSF correction achieves a least-square-error of only 4%. The third module generates a binary “cell” or “no cell” per-pixel labeling with an accuracy ranging from 89% to 85%. This work demonstrates the synergy between ultra-small silicon-based imagers that enable in vivo imaging but face a trade-off in spatial resolution, and the processing power of neural networks to achieve enhancements beyond conventional linear optimization techniques.

Augmented reality: the smart way to guide robotic urologic surgery

The development of a tailored, patient-specific medical and surgical approach is becoming the object of intense research. In robotic urologic surgery, where a clear understanding of case-specific surgical anatomy is considered a key point to optimizing the perioperative outcomes, such philosophy has gained increasing importance. Recently, significant advances in three-dimensional (3D) virtual modeling technologies have fueled the interest in their application in the field of robotic minimally invasive surgery for kidney and prostate tumors. The aim of the review is to provide a synthesis of current applications of 3D virtual models for robot-assisted radical prostatectomy and partial nephrectomy. Medline, PubMed, the Cochrane Database, and Embase were screened for literature regarding the use of 3D augmented reality (AR) during robot-assisted radical prostatectomy and partial nephrectomy. The use of 3D AR models for intraoperative surgical navigation has been tested in prostate and kidney surgery. Its application during robot-assisted radical prostatectomy has been reported by different groups as influencing the positive surgical margins rate and guiding selective bundle biopsy. In robot-assisted partial nephrectomy, AR guidance improves surgical strategy, leading to higher selective clamping, less healthy parenchyma loss, and better postoperative kidney function. In conclusion, the available literature suggests a potentially crucial role of 3D AR technology in improving perioperative results of robot-assisted urological procedures. In the future, artificial intelligence may represent the key to further improving this promising technology.

V04-06 3D AUGMENTED REALITY ROBOT ASSISTED PARTIAL NEPHRECTOMY GUIDED BY INDOCYANINE GREEN: A STEP NEARER TO “AUTOMATIC” OVERLAPPING?

You have accessJournal of UrologyAdrenal & Renal Oncology I (Nephron Sparing Surgery) (V04)1 Sep 2021V04-06 3D AUGMENTED REALITY ROBOT ASSISTED PARTIAL NEPHRECTOMY GUIDED BY INDOCYANINE GREEN: A STEP NEARER TO “AUTOMATIC” OVERLAPPING? Francesco Porpiglia, Daniele Amparore, Federico Piramide, Enrico Checcucci, Paolo Verri, Gabriele Volpi, Sabrina De Cillis, Alberto Piana, Pietro Piazzolla, Andrea Bellin, Matteo Manfredi, Vezzetti Enrico, and Cristian Fiori Francesco PorpigliaFrancesco Porpiglia More articles by this author , Daniele AmparoreDaniele Amparore More articles by this author , Federico PiramideFederico Piramide More articles by this author , Enrico CheccucciEnrico Checcucci More articles by this author , Paolo VerriPaolo Verri More articles by this author , Gabriele VolpiGabriele Volpi More articles by this author , Sabrina De CillisSabrina De Cillis More articles by this author , Alberto PianaAlberto Piana More articles by this author , Pietro PiazzollaPietro Piazzolla More articles by this author , Andrea BellinAndrea Bellin More articles by this author , Matteo ManfrediMatteo Manfredi More articles by this author , Vezzetti EnricoVezzetti Enrico More articles by this author , and Cristian FioriCristian Fiori More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002000.06AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: In the actual scenario of nephron sparing “precision” surgery, the availability of hyper-accuracy 3D models (HA3DTM) revealed to be useful thanks to their spatial visualization. In the last years, a step further was represented by the advent of Augmented Reality (AR) technology, in which the superimposition of 3D virtual images allowed an intraoperative surgical navigation. In this study, with the aim to automatize the 3D virtual and endoscopic images co-registration, we developed a dedicated software based on computer vision algorithms. METHODS: This is a feasibility study of our new dedicated software, named “IGNITE” (Indocyanine GreeN automatIc augmenTed rEality), able to automatically anchor the HA3DTM model with the endoscopic vision of the real organ. For this project we applied computer vision algorithms which need clear landmarks to correctly identify the target organ. In order to overcome the colors similarity of the operative field and to provide a more depictable shape for the software we decided to use indocyanine. In order to overcome the colors similarity of the operative field and to provide a more depictable shape for the software we decided to use indocyanine. In this way the kidney appears as a bright green organ surrounded by a dark operative field. We enrolled patients with renal mass scheduled for AR robot-assisted partial nephrectomy. All patients underwent a four-phase contrast-enhanced CT, in order to create the HA3D models, visualized as AR images inside the robotic console.Perioperative and postoperative data were collected and analyzed. RESULTS: Ten cases were enrolled in this pilot experience. Mean lesions size was 46.6 (+16.3) mm. Median PADUA score was 9 (IQR 8-10). Mean operative and ischemia time were 88.9 (+42.7) and 20.5 (3.5) min, respectively. In all the cases (even in completely endophytic or posterior tumors) the automatic tracking was successful without manual assistance by the operator, allowing to perform enucleoresection of the renal mass with no damages of the tumor’s pseudocapsule and avoiding positive surgical margins. Moreover, no intra- or postoperative complications (>2 according to Clavien- Dindo) were recorded. CONCLUSIONS: Present findings suggest that the new evolution of our AR platform based on computer vision algorithm allows an effective automatic AR RAPN. The automatic 3D model overlapping lead to a correct identification of the tumor, even in endophytic and posterior cases, without risk of complications or positive surgical margins. Source of Funding: N/a © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e292-e293 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Francesco Porpiglia More articles by this author Daniele Amparore More articles by this author Federico Piramide More articles by this author Enrico Checcucci More articles by this author Paolo Verri More articles by this author Gabriele Volpi More articles by this author Sabrina De Cillis More articles by this author Alberto Piana More articles by this author Pietro Piazzolla More articles by this author Andrea Bellin More articles by this author Matteo Manfredi More articles by this author Vezzetti Enrico More articles by this author Cristian Fiori More articles by this author Expand All Advertisement Loading ...

Intraoperative Surgical Navigation Reduces the Surgical Time Required to Treat Acute Major Facial Fractures

Intraoperative Surgical Navigation Reduces the Surgical Time Required to Treat Acute Major Facial Fractures

Quantitative evaluation of symmetry after navigation-guided surgical recontouring of zygomatic fibrous dysplasia: a comparative study

Zygomatic fibrous dysplasia is a slowly progressive disorder of bone, which commonly causes facial asymmetry. Precise surgical recontouring can effectively improve facial aesthetics. The aim of this study was to quantitatively evaluate the effectiveness of surgical navigation guidance in correcting zygomatic asymmetry. The study included 26 patients with unilateral zygomatic fibrous dysplasia who underwent bony recontouring. They were divided into two groups according to the use of intraoperative surgical navigation (navigation group and conventional group; n=13 in each group). Clinical outcomes were evaluated using three-dimensional computed tomography. Six pairs of landmarks were identified, and the coordinates were used to calculate asymmetry indices. The curvature of protruding regions in the surgical area was measured to determine facial skeletal symmetry in three dimensions. The results were compared between the groups. All patients recovered uneventfully and their facial symmetry and aesthetics improved. For three of the six pairs of landmarks, symmetry was better in the navigation group than in the conventional group (all P≤ 0.02). The postoperative curvature ratios were better (more symmetrical) in the navigation group (P= 0.01). Surgical navigation enhances postoperative facial symmetry. However, the clinical significance of this enhancement when compared to conventional non-navigation surgery needs further investigation.

Image-guided navigation for locally advanced primary and locally recurrent rectal cancer: Evaluation of its early cost-effectiveness.

e16015 Background: Radical resection is an important prognostic factor in patients with locally advanced primary (LARC) and locally recurrent rectal cancer (LRRC), but achieving this can be challenging. Therefore, an intraoperative surgical navigation system has been developed, showing improved radical resection rates for LARC and LRRC. This study evaluates the early cost-effectiveness of navigated surgery in LARC and LRRC compared to standard surgery. Methods: Two Markov decision models; one for each indication, were used to estimate the expected costs and outcomes for navigated and standard surgery from a Dutch healthcare perspective over a 3-year time horizon. The models started with a decision tree resulting in a radical or non-radical resection. Subsequently, the Markov-models comprised the health states “stable disease”, “progression” and “death”. The input parameters were based on prospective (navigation cohort n = 33) and retrospective (control group n = 142) data collected at the Netherlands Cancer Institute, reference and unit prices and expert opinion. Quality-Adjusted Life Years (QALYs) were measured by the EQ5D-5L. Additionally, a probabilistic sensitivity analysis and a scenario analysis were performed. Results: Navigated surgery showed incremental costs of €3139 and €2857 in LARC and LRRC, respectively. For LARC, for navigation and standard surgery we found: 2.54 vs 2.52 Life Years (LYs), and 2.06 vs 2.04 QALYs. For LRRC we found 2.17 vs 2.11 LYs and 1.73 vs 1.67 QALYs. The base case analysis showed an Incremental Cost-Effectiveness Ratio (ICER) of €144,192 for LARC and €51,802 for LRRC per QALY gained. At a willingness to pay threshold of €80,000, navigated surgery is not cost- effective in LARC but is cost-effective in LRRC. When a hospital lacks a hybrid OR and needs to invest in one to use the navigation system, which will increase the ICERs for both indications. Finally, more utilization of the navigation system (12% to 50% utilization rate) shows ICERs of € 65,257 and €20,648 for LARC and LRRC, respectively. Conclusions: Based on the current data, the navigation system is expected to be cost-effective in LRRC and has the potential to become cost-effective in LARC. To decrease the costs, it is crucial to identify more surgical indications for image-guided navigation. Especially as in the near future, image-guided surgery is expected to be a standard option in surgical practice. As these findings are sensitive to uncertainty in the data, a randomized controlled trial is advised to perform for relevant indications.

Intraoperative Surgical Navigation Reduces the Surgical Time Required to Treat Acute Major Facial Fractures.

Assessing bone reduction and implant placement in facial fractures is time-consuming because of limited visibility. An intraoperative navigation system allows real-time confirmation of bone positioning and implant placement on the patient's computed tomographic scan. This circumvents the visibility problem and therefore appears to shorten the surgery time. The goal of this study was therefore to determine whether intraoperative navigation reduces the surgical time required to treat patients with acute major facial fractures. In this retrospective quasi-experimental study, 50 patients with major facial fractures were identified and randomly assigned to treatment groups. Twenty-two were treated without the use of a navigation system, and 28 were treated using navigation. The Facial frActure Severity Score (FASS) was devised to better assess and control for complexity of cases and control for possible selection bias. The FASS was directly linked to surgery time, whether or not navigation was used. An analysis of covariance demonstrated that the surgical time required to treat major facial fractures, taking into account the FASS, was reduced by 36.1 percent (124.8 minutes) when navigation was used. This study compared the surgical time required to treat patients with major facial fractures, with and without a navigation system. The use of a navigation system reduced the surgical time by 36.1 percent. This is a significant improvement in reducing the length of craniomaxillofacial procedures. Therapeutic, III.

Intraoperative Image-Guided Navigation in Craniofacial Surgery: Review and Grading of the Current Literature

Image-guided navigation has existed for nearly 3 decades, but its adoption to craniofacial surgery has been slow. A systematic review of the literature was performed to assess the current status of navigation in craniofacial surgery. A Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) systematic review of the Medline and Web of Science databases was performed using a series of search terms related to Image-Guided Navigation and Craniofacial Surgery. Titles were then filtered for relevance and abstracts were reviewed for content. Single case reports were excluded as were animal, cadaver, and virtual data. Studies were categorized based on the type of study performed and graded using the Jadad scale and the Newcastle-Ottawa scales, when appropriate. A total of 2030 titles were returned by our search criteria. Of these, 518 abstracts were reviewed, 208 full papers were evaluated, and 104 manuscripts were ultimately included in the study. A single randomized controlled trial was identified (Jadad score 3), and 12 studies were identified as being case control or case cohort studies (Average Newcastle-Ottawa score 6.8) The most common application of intraoperative surgical navigation cited was orbital surgery (n = 36), followed by maxillary surgery (n = 19). Higher quality studies more commonly pertained to the orbit (6/13), and consistently show improved results. Image guided surgical navigation improves outcomes in orbital reconstruction. Although image guided navigation has promise in many aspects of craniofacial surgery, current literature is lacking and future studies addressing this paucity of data are needed before universal adoption can be recommended.