Registration Techniques for Clinical Applications of Three-Dimensional Augmented Reality Devices

Nephron-sparing Surgery for Pediatric Renal Tumors After Centralization of Pediatric Oncology Care in the Netherlands: Improved Outcomes With 3D Modeling

BACKGROUND AND AIM

In this retrospective single center cohort study, we report the surgical outcomes of nephron-sparing surgery (NSS) for Wilms' tumor (WT) patients since centralization of pediatric oncology care in the Netherlands, and implementation of technological advancements. Therewith we describe the influence of experience and innovations for this type of surgery.

METHODS

We retrospectively assessed all NSS procedures from January 1st 2015 until January 1st 2024 for patients who underwent surgery for a renal tumor at the Princess Máxima Center for Pediatric Oncology. Data were gathered on patient characteristics, diagnostic information, radiological characteristics, surgical technique and use of innovations, postoperative outcome, administered treatment and surgical follow-up.

RESULTS

36 patients (58 % female, 42 % male) were included with a total of 43 NSS procedures. Mean (SD) age at diagnosis was 33.3 (23.1) months. 16 procedures were performed without 3D models, of which 3 (18.8 %) resulted in an unexpected positive margin. 27 procedures were preoperatively planned with a 3D model with one (3.7 %) unexpected anticipated positive margins (p = 0.101). Six (13.9 %) procedures had post-operative complications including five urine leakages, one chyle leakage and two (reversible) acute kidney insufficiency. Four patients received a re-intervention (JJ-stent or drain).

CONCLUSIONS

In this retrospective single center cohort study, we show a good surgical outcome after NSS for children with renal tumors after the implementation of 3D models. This study can act as a baseline cohort to harmonize preoperative assessment, intraoperative technique and implementation of innovative surgical technology for further expansion of NSS for WT patients.

3D cinematic reconstructions of cardiovascular CT presented in augmented reality: subjective assessment of clinical feasibility and potential use cases

Augmented reality (AR) is a new technique enabling interaction with three-dimensional (3D) holograms of cinematic rendering (CR) reconstructions. Research in this field is in its very early steps, and data is scarce. We evaluated image quality, usability, and potential applications of AR in cardiovascular image datasets. Ten CR reconstructions of cardiovascular computed tomography (CT) datasets with complex anatomical abnormalities were presented to six radiologists and three cardiologists first on diagnostic screens and subsequently in AR. Subjective image quality and user experience were rated on 5-point Likert scales to assess usability and potential applications of AR. CR of CT datasets covering multiple images series of the same exam with differing kernels was performed in 143 ± 31 s (mean ± standard deviation); reconstruction of single CT image series took 84 ± 30 s. Mean subjective image quality was excellent, and observers showed high endorsement of the intuitive usability of the AR device and improvement of anatomical comprehensibility. AR devices were expected to have the greatest impact on patient and student education as well as multidisciplinary discussions, with less potential in clinical care. Clinical testing and preclinical implementation of AR seem feasible due to reasonable computation times and intuitive usability even for first-time users. RELEVANCE STATEMENT: The presentation of 3D cinematic rendering in augmented reality provides excellent image quality, facilitating the comprehension of anatomical structures in CT datasets. Concurrently, reasonable computation times and the intuitive usability of augmented reality devices make preclinical implementation and clinical testing feasible. KEY POINTS: 3D cinematic reconstructions presented in augmented reality improve the anatomical comprehensibility of chest CT scans. Augmented reality devices are expected to be highly beneficial in educational settings and multidisciplinary discussions. Usability and computation times are feasible for initial preclinical use cases.

A novel minimally invasive neurosurgical cranial fixation device for improved accuracy of intraventricular catheter placement: an experimental animal study

BACKGROUND

External ventricular drain (EVD) insertion is one of the most commonly performed neurosurgical procedures. Herein, we introduce a new concept of a cranial fixation device for insertion of EVDs, that reduces reliance on freehand placement and drilling techniques and provides a simple, minimally invasive approach that provides strong fixation to minimal thickness skulls.

METHODS

An experimental device for catheter insertion and fixation was designed and tested in both ex-vivo and in-vivo conditions to assess accurate cannulation of the ventricle and to test the strength of fixation to the skull. The ex-vivo experiments were conducted at Ben-Gurion University of the Negev (BGU) in Be'er Sheva, Israel. These experiments included functionality bench testing and pullout force measurements for the ball mechanism and catheter fixation. For the in-vivo experiments the fixation device was initially tested at the Cincinnati Children's Hospital Medical Center (CCHMC) in Cincinnati, Ohio on one day of life 1 (DOL 1) male control lamb. Additional experiments were conducted on 3 hydrocephalic DOL 0 lambs (1 male 2 female) at the Jesús Usón Minimally Invasive Surgery Centre (JUMISC) in Caceres, Spain. The hydrocephalic animal model used for this study was created with in utero intracisternal injection of BioGlue in fetal lambs. The catheter insertion trajectory was determined using MR imaging to assess the device's impact on the placement accuracy. The fixation device was evaluated on reaching the ventricle and enabling extraction of CSF for all 7 fixations placed. For 5 of the fixation devices, post-mortem pullout force was measured. The general functionality of the device was also evaluated.

RESULTS

In the experiments, 7/7 (100%) catheter trajectories successfully reached the ventricle without any apparent complications related to the device or the procedure. The cranial fixation device base demonstrated significant strength in withstanding an average pull-out force of 4.18kgf (STD[Formula: see text]0.72, N = 5) without detachment from the subject's skull for all 5 devices included in this test. Additionally, the EVD catheter pull test was conducted with the addition of a safety loop which did not allow movement of the EVD to a force of 3.6kgf. At this force the catheter tore but did not release from its fixation point.

CONCLUSION

The newly designed experimental device demonstrates initial proof of concept from ex vivo and in vivo testing. It appears suitable for accurate ventricular catheter placement and cranial fixation.

First-in-human trial using mixed-reality visualization for patient setup during breast or chest wall radiotherapy

BACKGROUND

The purpose of this study is to assess the feasibility of mixed-reality (MixR) visualization for patient setup in breast and chest wall radiotherapy (RT) by performing a first-in-human clinical trial comparing MixR with a 3-point alignment.

METHODS

IRB approval was granted for a study incorporating MixR during the setup process for patients undergoing proton (n = 10) or photon (n = 8) RT to the breast or chest wall. For each patient, MixR was utilized for five fractions and compared against another five fractions using 3-point alignment. During fractions with MixR, the patient was aligned by at least one therapist wearing a HoloLens 2 device who was able to guide the process by simultaneously and directly viewing the patient and a hologram of the patient's surface derived from their simulation CT scan. Alignment accuracy was quantified with cone-beam CT (CBCT) for photon treatments and CBCT plus kV/kV imaging for proton treatments. Registration time was tracked throughout the setup process as well as the amount of image guidance (IGRT) utilized for final alignment.

RESULTS

In the proton cohort, the mean 3D shift was 0.96 cm using 3-point alignment and 1.18 cm using MixR. An equivalence test indicated that the difference in registration accuracy between the two techniques was less than 0.5 cm. In the photon cohort, the mean 3D shift was 1.18 cm using 3-point alignment and 1.00 cm using MixR. An equivalence test indicated that the difference in registration accuracy was less than 0.3 cm. Minor differences were seen in registration time and the amount of IGRT utilization.

CONCLUSIONS

MixR for patient setup for breast cancer RT is possible at the level of accuracy and efficiency provided by a 3-point alignment. Further developments in marker tracking, feedback, and a better understanding of the perceptual challenges of MixR are needed to achieve a similar level of accuracy as provided by modern surface-guided radiotherapy (SGRT) systems.

TRIAL REGISTRATION

ClinicalTrials.gov, UFHPTI 2015-BR05: Improving Breast Radiotherapy Setup and Delivery Using Mixed-Reality Visualization, NCT05178927.

Feasibility of augmented reality using dental arch-based registration applied to navigation in mandibular distraction osteogenesis: a phantom experiment

OBJECTIVE

Distraction osteogenesis is a primary treatment for severe mandibular hypoplasia. Achieving the ideal mandible movement direction through precise distraction vector control is still a challenge in this surgery. Therefore, the aim of this study was to apply Optical See-Through (OST) Augmented Reality (AR) technology for intraoperative navigation during mandibular distractor installation and analyze the feasibility to evaluate the effectiveness of AR in a phantom experiment.

METHODS

Phantom was made of 3D-printed mandibular models based on preoperative CT scans and dental arch scans of real patients. Ten sets of 3D-printed mandible models were included in this study, with each set consisting of two identical mandible models assigned to the AR group and free-hand group. 10 sets of mandibular distraction osteogenesis surgical plans were designed using software, and the same set of plans was shared between the AR and free-hand groups. Surgeons performed bilateral mandibular distraction osteogenesis tasks under the guidance of AR navigation, or the reference of the preoperative surgical plan displayed on the computer screen. The differences in angular errors of distraction vectors and the distance errors of distractor positions under the guidance of the two methods were analyzed and compared.

RESULTS

40 distractors were implanted in both groups, with 20 cases in each. In intra-group comparisons between the left and right sides, the AR group exhibited a three-dimensional spatial angle error of 1.88 (0.59, 2.48) on the left and 2.71 (1.33, 3.55) on the right, with P = 0.085, indicating no significant bias in guiding surgery on both sides of the mandible. In comparisons between the AR group and the traditional free-hand (FH) group, the average angle error was 1.94 (1.30, 2.93) in the AR group and 5.06 (3.61, 9.22) in the free-hand group, with P < 0.0001, resulting in a 61.6% improvement in accuracy. The average displacement error was 1.53 ± 0.54 mm in the AR group and 3.56 ± 1.89 mm in the free-hand group, with P < 0.0001, indicating a 57% improvement in accuracy.

CONCLUSION

Augmented Reality technology for intraoperative navigation in mandibular distraction osteogenesis is accurate and feasible. A large randomized controlled trial with long-term follow-up is needed to confirm these findings.

TRIAL REGISTRATION

The project has been registered with the Chinese Clinical Trial Registry, with registration number ChiCTR2300068417. Date of Registration: 17 February 2023.

Medical Extended Reality for Radiology Education and Training

Medical extended reality (MXR), encompassing augmented reality, virtual reality, and mixed reality (MR), presents a novel paradigm in radiology training by offering immersive, interactive, and realistic learning experiences in health care. Although traditional educational tools in the field of radiology are essential, it is necessary to capitalize on the innovative and emerging educational applications of extended reality (XR) technologies. At the most basic level of learning anatomy, XR has been extensively used with an emphasis on its superiority over conventional learning methods, especially in spatial understanding and recall. For imaging interpretation, XR has fostered the concepts of virtual reading rooms by enabling collaborative learning environments and enhancing image analysis and understanding. Moreover, image-guided interventions in interventional radiology have witnessed an uptick in XR utilization, illustrating its effectiveness in procedural training and skill acquisition for medical students and residents in a safe and risk-free environment. However, there remain several challenges and limitations for XR in radiology education, including technological, economic, and ergonomic challenges and and integration into existing curricula. This review explores the transformative potential of MXR in radiology education and training along with insights on the future of XR in radiology education, forecasting advancements in immersive simulations, artificial intelligence integration for personalized learning, and the potential of cloud-based XR platforms for remote and collaborative training. In summation, MXR's burgeoning role in reshaping radiology education offers a safer, scalable, and more efficient training model that aligns with the dynamic healthcare landscape.

Is the Apple Vision Pro the Ultimate Display? A First Perspective and Survey on Entering the Wonderland of Precision Medicine

At the Worldwide Developers Conference in June 2023, Apple introduced the Vision Pro. The Apple Vision Pro (AVP) is a mixed reality headset; more specifically, it is a virtual reality device with an additional video see-through capability. The video see-through capability turns the AVP into an augmented reality (AR) device. The AR feature is enabled by streaming the real world via cameras on the (virtual reality) screens in front of the user's eyes. This is, of course, not unique and is similar to other devices, such as the Varjo XR-3 (Varjo Technologies Oy). Nevertheless, the AVP has some interesting features, such as an inside-out screen that can show the headset wearer's eyes to "outsiders," and a button on the top, called the "digital crown," that allows a seamless blend of digital content with the user's physical space by turning it. In addition, it is untethered, except for the cable to the battery, which makes the headset more agile, compared to the Varjo XR-3. This could actually come closer to "The Ultimate Display," which Ivan Sutherland had already sketched in 1965. After a great response from the media and social networks to the release, we were able to test and review the new AVP ourselves in March 2024. Including an expert survey with 13 of our colleagues after testing the AVP in our institute, this Viewpoint explores whether the AVP can overcome clinical challenges that AR especially still faces in the medical domain; we also go beyond this and discuss whether the AVP could support clinicians in essential tasks to allow them to spend more time with their patients.

Phantom study of augmented reality framework to assist epicardial punctures

Purpose

The objective of this study is to evaluate the accuracy of an augmented reality (AR) system in improving guidance, accuracy, and visualization during the subxiphoidal approach for epicardial ablation.

Approach

An AR application was developed to project real-time needle trajectories and patient-specific 3D organs using the Hololens 2. Additionally, needle tracking was implemented to offer real-time feedback to the operator, facilitating needle navigation. The AR application was evaluated through three different experiments: examining overlay accuracy, assessing puncture accuracy, and performing pre-clinical evaluations on a phantom.

Results

The results of the overlay accuracy assessment for the AR system yielded 2.36 ± 2.04    mm . Additionally, the puncture accuracy utilizing the AR system yielded 1.02 ± 2.41    mm . During the pre-clinical evaluation on the phantom, needle puncture with AR guidance showed 7.43 ± 2.73    mm , whereas needle puncture without AR guidance showed 22.62 ± 9.37    mm .

Conclusions

Overall, the AR platform has the potential to enhance the accuracy of percutaneous epicardial access for mapping and ablation of cardiac arrhythmias, thereby reducing complications and improving patient outcomes. The significance of this study lies in the potential of AR guidance to enhance the accuracy and safety of percutaneous epicardial access.

Single-center experience with Knee+™ augmented reality navigation system in primary total knee arthroplasty

BACKGROUND

Computer-assisted systems obtained an increased interest in orthopaedic surgery over the last years, as they enhance precision compared to conventional hardware. The expansion of computer assistance is evolving with the employment of augmented reality. Yet, the accuracy of augmented reality navigation systems has not been determined.

AIM

To examine the accuracy of component alignment and restoration of the affected limb's mechanical axis in primary total knee arthroplasty (TKA), utilizing an augmented reality navigation system and to assess whether such systems are conspicuously fruitful for an accomplished knee surgeon.

METHODS

From May 2021 to December 2021, 30 patients, 25 women and five men, underwent a primary unilateral TKA. Revision cases were excluded. A preoperative radiographic procedure was performed to evaluate the limb's axial alignment. All patients were operated on by the same team, without a tourniquet, utilizing three distinct prostheses with the assistance of the Knee+™ augmented reality navigation system in every operation. Postoperatively, the same radiographic exam protocol was executed to evaluate the implants' position, orientation and coronal plane alignment. We recorded measurements in 3 stages regarding femoral varus and flexion, tibial varus and posterior slope. Firstly, the expected values from the Augmented Reality system were documented. Then we calculated the same values after each cut and finally, the same measurements were recorded radiologically after the operations. Concerning statistical analysis, Lin's concordance correlation coefficient was estimated, while Wilcoxon Signed Rank Test was performed when needed.

RESULTS

A statistically significant difference was observed regarding mean expected values and radiographic measurements for femoral flexion measurements only (Z score = 2.67, P value = 0.01). Nonetheless, this difference was statistically significantly lower than 1 degree (Z score = -4.21, P value < 0.01). In terms of discrepancies in the calculations of expected values and controlled measurements, a statistically significant difference between tibial varus values was detected (Z score = -2.33, P value = 0.02), which was also statistically significantly lower than 1 degree (Z score = -4.99, P value < 0.01).

CONCLUSION

The results indicate satisfactory postoperative coronal alignment without outliers across all three different implants utilized. Augmented reality navigation systems can bolster orthopaedic surgeons' accuracy in achieving precise axial alignment. However, further research is required to further evaluate their efficacy and potential.

Augmented Reality Navigation System for Biliary Interventional Procedures With Dynamic Respiratory Motion Correction

OBJECTIVE

Biliary interventional procedures require physicians to track the interventional instrument tip (Tip) precisely with X-ray image. However, Tip positioning relies heavily on the physicians' experience due to the limitations of X-ray imaging and the respiratory interference, which leads to biliary damage, prolonged operation time, and increased X-ray radiation.

METHODS

We construct an augmented reality (AR) navigation system for biliary interventional procedures. It includes system calibration, respiratory motion correction and fusion navigation. Firstly, the magnetic and 3D computed tomography (CT) coordinates are aligned through system calibration. Secondly, a respiratory motion correction method based on manifold regularization is proposed to correct the misalignment of the two coordinates caused by respiratory motion. Thirdly, the virtual biliary, liver and Tip from CT are overlapped to the corresponding position of the patient for dynamic virtual-real fusion.

RESULTS

Our system is respectively evaluated and achieved an average alignment error of 0.75 ± 0.17 mm and 2.79 ± 0.46 mm on phantoms and patients. The navigation experiments conducted on phantoms achieve an average Tip positioning error of 0.98 ± 0.15 mm and an average fusion error of 1.67 ± 0.34 mm after correction.

CONCLUSION

Our system can automatically register the Tip to the corresponding location in CT, and dynamically overlap the 3D virtual model onto patients to provide accurate and intuitive AR navigation.

SIGNIFICANCE

This study demonstrates the clinical potential of our system by assisting physicians during biliary interventional procedures. Our system enables dynamic visualization of virtual model on patients, reducing the reliance on contrast agents and X-ray usage.

Exposure to Extended Reality and Artificial Intelligence-Based Manifestations: A Primer on the Future of Hip and Knee Arthroplasty

BACKGROUND

Software-infused services, from robot-assisted and wearable technologies to artificial intelligence (AI)-laden analytics, continue to augment clinical orthopaedics - namely hip and knee arthroplasty. Extended reality (XR) tools, which encompass augmented reality, virtual reality, and mixed reality technology, represent a new frontier for expanding surgical horizons to maximize technical education, expertise, and execution. The purpose of this review is to critically detail and evaluate the recent developments surrounding XR in the field of hip and knee arthroplasty and to address potential future applications as they relate to AI.

METHODS

In this narrative review surrounding XR, we discuss (1) definitions, (2) techniques, (3) studies, (4) current applications, and (5) future directions. We highlight XR subsets (augmented reality, virtual reality, and mixed reality) as they relate to AI in the increasingly digitized ecosystem within hip and knee arthroplasty.

RESULTS

A narrative review of the XR orthopaedic ecosystem with respect to XR developments is summarized with specific emphasis on hip and knee arthroplasty. The XR as a tool for education, preoperative planning, and surgical execution is discussed with future applications dependent upon AI to potentially obviate the need for robotic assistance and preoperative advanced imaging without sacrificing accuracy.

CONCLUSION

In a field where exposure is critical to clinical success, XR represents a novel stand-alone software-infused service that optimizes technical education, execution, and expertise but necessitates integration with AI and previously validated software solutions to offer opportunities that improve surgical precision with or without the use of robotics and computed tomography-based imaging.

A survey of augmented reality methods to guide minimally invasive partial nephrectomy

INTRODUCTION

Minimally invasive partial nephrectomy (MIPN) has become the standard of care for localized kidney tumors over the past decade. The characteristics of each tumor, in particular its size and relationship with the excretory tract and vessels, allow one to judge its complexity and to attempt predicting the risk of complications. The recent development of virtual 3D model reconstruction and computer vision has opened the way to image-guided surgery and augmented reality (AR).

OBJECTIVE

Our objective was to perform a systematic review to list and describe the different AR techniques proposed to support PN.

MATERIALS AND METHODS

The systematic review of the literature was performed on 12/04/22, using the keywords "nephrectomy" and "augmented reality" on Embase and Medline. Articles were considered if they reported surgical outcomes when using AR with virtual image overlay on real vision, during ex vivo or in vivo MIPN. We classified them according to the registration technique they use.

RESULTS

We found 16 articles describing an AR technique during MIPN procedures that met the eligibility criteria. A moderate to high risk of bias was recorded for all the studies. We classified registration methods into three main families, of which the most promising one seems to be surface-based registration.

CONCLUSION

Despite promising results, there do not exist studies showing an improvement in clinical outcomes using AR. The ideal AR technique is probably yet to be established, as several designs are still being actively explored. More clinical data will be required to establish the potential contribution of this technology to MIPN.

Three-dimensional technologies in presurgical planning of bone surgeries: current evidence and future perspectives

BACKGROUND

The recent development of three-dimensional (3D) technologies introduces a novel set of opportunities to the medical field in general, and specifically to surgery. The preoperative phase has proven to be a critical factor in surgical success. Utilization of 3D technologies has the potential to improve preoperative planning and overall surgical outcomes. In this narrative review article, the authors describe existing clinical data pertaining to the current use of 3D printing, virtual reality, and augmented reality in the preoperative phase of bone surgery.

METHODS

The methodology included keyword-based literature search in PubMed and Google Scholar for original articles published between 2014 and 2022. After excluding studies performed in nonbone surgery disciplines, data from 61 studies of five different surgical disciplines were processed to be included in this narrative review.

RESULTS

Among the mentioned technologies, 3D printing is currently the most advanced in terms of clinical use, predominantly creating anatomical models and patient-specific instruments that provide high-quality operative preparation. Virtual reality allows to set a surgical plan and to further simulate the procedure via a 2D screen or head mounted display. Augmented reality is found to be useful for surgical simulation upon 3D printed anatomical models or virtual phantoms.

CONCLUSIONS

Overall, 3D technologies are gradually becoming an integral part of a surgeon's preoperative toolbox, allowing for increased surgical accuracy and reduction of operation time, mainly in complex and unique surgical cases. This may eventually lead to improved surgical outcomes, thereby optimizing the personalized surgical approach.

Surgical Navigation System for Hypertensive Intracerebral Hemorrhage Based on Mixed Reality

Hypertensive intracerebral hemorrhage (HICH) is an intracerebral bleeding disease that affects 2.5 per 10,000 people worldwide each year. An effective way to cure this disease is puncture through the dura with a brain puncture drill and tube; the accuracy of the insertion determines the quality of the surgery. In recent decades, surgical navigation systems have been widely used to improve the accuracy of surgery and minimize risks. Augmented reality- and mixed reality-based surgical navigation is a promising new technology for surgical navigation in the clinic, aiming to improve the safety and accuracy of the operation. In this study, we present a novel multimodel mixed reality navigation system for HICH surgery in which medical images and virtual anatomical structures can be aligned intraoperatively with the actual structures of the patient in a head-mounted device and adjusted when the patient moves in real time while under local anesthesia; this approach can help the surgeon intuitively perform intraoperative navigation. A novel registration method is used to register the holographic space and serves as an intraoperative optical tracker, and a method for calibrating the HICH surgical tools is used to track the tools in real time. The results of phantom experiments revealed a mean registration error of 1.03 mm and an average time consumption of 12.9 min. In clinical usage, the registration error was 1.94 mm, and the time consumption was 14.2 min, showing that this system is sufficiently accurate and effective for clinical application.

Augmented Reality in Vascular and Endovascular Surgery: Scoping Review

BACKGROUND

Technological advances have transformed vascular intervention in recent decades. In particular, improvements in imaging and data processing have allowed for the development of increasingly complex endovascular and hybrid interventions. Augmented reality (AR) is a subject of growing interest in surgery, with the potential to improve clinicians' understanding of 3D anatomy and aid in the processing of real-time information. This study hopes to elucidate the potential impact of AR technology in the rapidly evolving fields of vascular and endovascular surgery.

OBJECTIVE

The aim of this review is to summarize the fundamental concepts of AR technologies and conduct a scoping review of the impact of AR and mixed reality in vascular and endovascular surgery.

METHODS

A systematic search of MEDLINE, Scopus, and Embase was performed in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. All studies written in English from inception until January 8, 2021, were included in the search. Combinations of the following keywords were used in the systematic search string: ("augmented reality" OR "hololens" OR "image overlay" OR "daqri" OR "magic leap" OR "immersive reality" OR "extended reality" OR "mixed reality" OR "head mounted display") AND ("vascular surgery" OR "endovascular"). Studies were selected through a blinded process between 2 investigators (JE and AS) and assessed using data quality tools.

RESULTS

AR technologies have had a number of applications in vascular and endovascular surgery. Most studies (22/32, 69%) used 3D imaging of computed tomography angiogram-derived images of vascular anatomy to augment clinicians' anatomical understanding during procedures. A wide range of AR technologies were used, with heads up fusion imaging and AR head-mounted displays being the most commonly applied clinically. AR applications included guiding open, robotic, and endovascular surgery while minimizing dissection, improving procedural times, and reducing radiation and contrast exposure.

CONCLUSIONS

AR has shown promising developments in the field of vascular and endovascular surgery, with potential benefits to surgeons and patients alike. These include reductions in patient risk and operating times as well as in contrast and radiation exposure for radiological interventions. Further technological advances are required to overcome current limitations, including processing capacity and vascular deformation by instrumentation.

Current trends in three-dimensional visualization and real-time navigation as well as robot-assisted technologies in hepatobiliary surgery

With the continuous development of digital medicine, minimally invasive precision and safety have become the primary development trends in hepatobiliary surgery. Due to the specificity and complexity of hepatobiliary surgery, traditional preoperative imaging techniques such as computed tomography and magnetic resonance imaging cannot meet the need for identification of fine anatomical regions. Imaging-based three-dimensional (3D) reconstruction, virtual simulation of surgery and 3D printing optimize the surgical plan through preoperative assessment, improving the controllability and safety of intraoperative operations, and in difficult-to-reach areas of the posterior and superior liver, assistive robots reproduce the surgeon's natural movements with stable cameras, reducing natural vibrations. Electromagnetic navigation in abdominal surgery solves the problem of conventional surgery still relying on direct visual observation or preoperative image assessment. We summarize and compare these recent trends in digital medical solutions for the future development and refinement of digital medicine in hepatobiliary surgery.