Mixed-Reality-Assisted Puncture of the Common Femoral Artery in a Phantom Model

Extended and augmented reality in vascular surgery: Opportunities and challenges

Extended reality has brought new opportunities for medical imaging visualization and analysis. It regroups various subfields, including virtual reality, augmented reality, and mixed reality. Various applications have been proposed for surgical practice, as well as education and training. The aim of this review was to summarize current applications of extended reality and augmented reality in vascular surgery, highlighting potential benefits, pitfalls, limitations, and perspectives on improvement.

Comparing Different Registration and Visualization Methods for Navigated Common Femoral Arterial Access-A Phantom Model Study Using Mixed Reality

Mixed reality (MxR) enables the projection of virtual three-dimensional objects into the user's field of view via a head-mounted display (HMD). This phantom model study investigated three different workflows for navigated common femoral arterial (CFA) access and compared it to a conventional sonography-guided technique as a control. A total of 160 punctures were performed by 10 operators (5 experts and 5 non-experts). A successful CFA puncture was defined as puncture at the mid-level of the femoral head with the needle tip at the central lumen line in a 0° coronary insertion angle and a 45° sagittal insertion angle. Positional errors were quantified using cone-beam computed tomography following each attempt. Mixed effect modeling revealed that the distance from the needle entry site to the mid-level of the femoral head is significantly shorter for navigated techniques than for the control group. This highlights that three-dimensional visualization could increase the safety of CFA access. However, the navigated workflows are infrastructurally complex with limited usability and are associated with relevant cost. While navigated techniques appear as a potentially beneficial adjunct for safe CFA access, future developments should aim to reduce workflow complexity, avoid optical tracking systems, and offer more pragmatic methods of registration and instrument tracking.

Immersive Innovations: Exploring the Diverse Applications of Virtual Reality (VR) in Healthcare

Virtual reality (VR) has experienced a remarkable evolution over recent decades, evolving from its initial applications in specific military domains to becoming a ubiquitous and easily accessible technology. This thorough review delves into the intricate domain of VR within healthcare, seeking to offer a comprehensive understanding of its historical evolution, theoretical foundations, and current adoption status. The examination explores the advantages of VR in enhancing the educational experience for medical students, with a particular focus on skill acquisition and retention. Within this exploration, the review dissects the applications of VR across diverse medical disciplines, highlighting its role in surgical training and anatomy/physiology education. While navigating the expansive landscape of VR, the review addresses challenges related to technology and pedagogy, providing insights into overcoming technical hurdles and seamlessly integrating VR into healthcare practices. Additionally, the review looks ahead to future directions and emerging trends, examining the potential impact of technological advancements and innovative applications in healthcare. This review illuminates the transformative potential of VR as a tool poised to revolutionize healthcare practices.

Application of Mixed Reality to Ultrasound-guided Femoral Arterial Cannulation During Real-time Practice in Cardiac Interventions

Mixed reality opens interesting possibilities as it allows physicians to interact with both, the real physical and the virtual computer-generated environment and objects, in a powerful way. A mixed reality system, based in the HoloLens 2 glasses, has been developed to assist cardiologists in a quite complex interventional procedure: the ultrasound-guided femoral arterial cannulations, during real-time practice in interventional cardiology. The system is divided into two modules, the transmitter module, responsible for sending medical images to HoloLens 2 glasses, and the receiver module, hosted in the HoloLens 2, which renders those medical images, allowing the practitioner to watch and manage them in a 3D environment. The system has been successfully used, between November 2021 and August 2022, in up to 9 interventions by 2 different practitioners, in a large public hospital in central Spain. The practitioners using the system confirmed it as easy to use, reliable, real-time, reachable, and cost-effective, allowing a reduction of operating times, a better control of typical errors associated to the interventional procedure, and opening the possibility to use the medical imagery produced in ubiquitous e-learning. These strengths and opportunities were only nuanced by the risk of potential medical complications emerging from system malfunction or operator errors when using the system (e.g., unexpected momentary lag). In summary, the proposed system can be taken as a realistic proof of concept of how mixed reality technologies can support practitioners when performing interventional and surgical procedures during real-time daily practice.

A New Method for Common Femoral Arterial Access Using a Mixed Reality-Assisted Technique on a Phantom Model

PURPOSE

The purpose of this study was to investigate the technical feasibility and usability of a mixed reality (MiR)-assisted common femoral arterial (CFA) access technique using a sonography-assisted registration method.

MATERIALS AND METHODS

A total of 60 CFA punctures were performed on a phantom model by 2 observers. Thirty punctures were performed using MiR (MiR group) and 30 punctures were performed using a conventional sonography-guided access procedure (control group). In the MiR group, a virtual object was created based on a computed tomography (CT) angiography scan of the model and registered to the physical patient in an MiR environment utilizing a software prototype that allowed registration based on a sonography scan. Positional error assessment encompassed 4 measurements using cone beam CT scans: (1) distance of the needle tip to the centerline, (2) distance of the needle entry site from the mid-level of the ostium of the profound femoral artery, (3) angle of entry of the needle in coronal, and (4) sagittal planes. Technical success rates as well as positional errors were compared between both groups. In addition, the usability of the system was assessed according to the system usability scale (SUS).

RESULTS

Technical success was 96.7% and 100% in the MiR and control groups, respectively. The median distance between the needle tip and the centerline was 3.0 (interquartile range [IQR]: 2.0-4.6) in the MiR group and 3.2 mm (IQR: 2.3-3.9) (p=0.63) in the control group. Similarly, the median distance from the needle entry site to the mid-level of the ostium of the profound femoral artery was 3.0 mm (IQR: 2.0-5.0) in the MiR group and 4.5 mm (IQR: 2.0-7.8) (p=0.18) in the control group. The median coronal angles of needle entry were 7.5° (IQR: 6-11) and 6° (IQR: 2-12) (p=0.13), and the median sagittal angles were 50° (IQR: 47-51) and 51° (IQR: 50-55) (p<0.01) in the MiR and control groups, respectively. The mean SUS score provided by both observers was 51.3.

CONCLUSION

The feasibility of an MiR-assisted CFA access technique could be demonstrated on a phantom model. Further studies are needed to investigate the technique beyond phantom model experiments and in different anatomical settings.

CLINICAL IMPACT

This study demonstrates the technical feasibility of a Mixed-Reality-assisted common femoral arterial access procedure on a phantom model. The positional accuracy was comparable to a conventional sonography-guided technique. However, there are several limitations that need to be resolved prior to potential implementation into clinical practice. Further studies are needed to investigate its performance beyond phantom model experiments and the prototypical application requires further technical refinement to increase its usability.

Risk Factors for Postoperative Puncture Site Bleeding after Interventional Treatment of Cerebrovascular Disease via Common Femoral Artery Puncture: A Retrospective Analysis of 710 Cases

This study aimed to identify the risk factors associated with puncture site bleeding following percutaneous puncture of the common femoral artery during interventional treatment of cerebrovascular disease (CVD). A retrospective analysis was conducted on 710 patients who underwent interventional treatment for CVD via femoral artery puncture. Among them, 26 individuals (3.66%) experienced bleeding at the femoral artery puncture site. Binary logistic regression analysis was performed to identify risk factors for puncture site bleeding. The impact of salt bag compression on postoperative bleeding was evaluated in patients with intermediate to high bleeding risk scores. The bleeding group showed higher blood pressure, lower platelet counts, longer prothrombin time and activated partial thromboplastin time, as well as a higher prevalence of larger vascular sheath sizes and variations in the timing of anti-coagulant and anti-platelet therapy administration. The bleeding risk score was higher in the bleeding group, indicating its predictive value for bleeding risk. Higher bleeding risk score, unstable blood pressure, repeated puncture, and serious vascular conditions were significant risk factors for puncture site bleeding. Application of salt bag compression for a duration of 2 hours reduced postoperative puncture site bleeding in patients with intermediate to high bleeding risk scores. Our study identified several significant risk factors for puncture site bleeding after cerebral vascular intervention via femoral artery puncture, including the bleeding risk score, blood pressure, repeated puncture, and vascular conditions. Implementing salt bag compression as a preventive measure can help mitigate bleeding complications in these high-risk patients.

Merging virtual and physical experiences: extended realities in cardiovascular medicine

Technological advancement and the COVID-19 pandemic have brought virtual learning and working into our daily lives. Extended realities (XR), an umbrella term for all the immersive technologies that merge virtual and physical experiences, will undoubtedly be an indispensable part of future clinical practice. The intuitive and three-dimensional nature of XR has great potential to benefit healthcare providers and empower patients and physicians. In the past decade, the implementation of XR into cardiovascular medicine has flourished such that it is now integrated into medical training, patient education, pre-procedural planning, intra-procedural visualization, and post-procedural care. This review article discussed how XR could provide innovative care and complement traditional practice, as well as addressing its limitations and considering its future perspectives.

Accuracy Evaluation Trial of Mixed Reality-Guided Spinal Puncture Technology

Purpose

To evaluate the accuracy of mixed reality (MR)-guided visualization technology for spinal puncture (MRsp).

Methods

MRsp involved the following three steps: 1. Lumbar spine computed tomography (CT) data were obtained to reconstruct virtual 3D images, which were imported into a HoloLens (2nd gen). 2. The patented MR system quickly recognized the spatial orientation and superimposed the virtual image over the real spine in the HoloLens. 3. The operator performed the spinal puncture with structural information provided by the virtual image. A posture fixation cushion was used to keep the subjects' lateral decubitus position consistent. 12 subjects were recruited to verify the setup error and the registration error. The setup error was calculated using the first two CT scans and measuring the displacement of two location markers. The projection points of the upper edge of the L3 spinous process (L3↑), the lower edge of the L3 spinous process (L3↓), and the lower edge of the L4 spinous process (L4↓) in the virtual image were positioned and marked on the skin as the registration markers. A third CT scan was performed to determine the registration error by measuring the displacement between the three registration markers and the corresponding real spinous process edges.

Results

The setup errors in the position of the cranial location marker between CT scans along the left-right (LR), anterior-posterior (AP), and superior-inferior (SI) axes of the CT bed measured 0.09 ± 0.06 cm, 0.30 ± 0.28 cm, and 0.22 ± 0.12 cm, respectively, while those of the position of the caudal location marker measured 0.08 ± 0.06 cm, 0.29 ± 0.18 cm, and 0.18 ± 0.10 cm, respectively. The registration errors between the three registration markers and the subject's real L3↑, L3↓, and L4↓ were 0.11 ± 0.09 cm, 0.15 ± 0.13 cm, and 0.13 ± 0.10 cm, respectively, in the SI direction.

Conclusion

This MR-guided visualization technology for spinal puncture can accurately and quickly superimpose the reconstructed 3D CT images over a real human spine.

Mixed Reality in der Gefäßchirurgie – ein Scoping Review

Hintergrund „Mixed Reality“ (MR) erlaubt die Projektion von virtuellen Objekten in das Sichtfeld des Anwenders durch ein Head-mounted Display (HMD). Im gefäßchirurgischen Behandlungsspektrum könnten MR-Anwendungen in Zukunft einen Nutzen darstellen. Im folgenden Scoping Review soll eine Orientierung über die aktuelle Anwendung der genannten Technologien im Bereich der Gefäßchirurgie gegeben und Forschungsziele für die Zukunft definiert werden. Material und Methoden Es erfolgte eine systematische Literaturrecherche in PubMed (MEDLINE) mit den Suchbegriffen „aorta“, „intervention“, „endovsacular intervention“, „vascular surgery“, „aneurysm“, „endovascular“, „vascular access“ jeweils in Kombination mit „mixed reality“ oder „augmented reality“. Die Suche erfolgte nach PRISMA-Leitlinie (Preferred Reporting Items for Systematic reviews and Meta-Analyses) für Scoping Reviews. Ergebnisse Aus 547 Literaturstellen konnten 8 relevante Studien identifiziert werden. Die Suchergebnisse konnten in 2 Anwendungskategorien eingeteilt werden: (1) MR mit dem Ziel des Informationsmanagements und zur Verbesserung der periprozeduralen Ergonomie gefäßchirurgischer Eingriffe (n = 3) sowie (2) MR mit dem Ziel der intraoperativen Navigation bei gefäßchirurgischen Eingriffen (n = 5). Die Registrierung des physischen Patienten mit dem virtuellen Objekt und das Tracking von Instrumenten in der MR-Umgebung zur intraoperativen Navigation ist dabei im Fokus des wissenschaftlichen Interesses und konnte technisch erfolgreich am Phantom- und Tiermodell gezeigt werden. Die bisher vorgestellten Methoden sind jedoch mit hohem infrastrukturellem Aufwand und relevanten Limitationen verbunden. Schlussfolgerung Der Einsatz von MR im Bereich der Gefäßchirurgie ist grundsätzlich vielversprechend. Für die Zukunft sollten alternative, pragmatische Registrierungsmethoden mit entsprechender Quantifizierung des Positionierungsfehlers angestrebt werden. Die entwickelten Soft- und Hardwarelösungen sollten auf das Anforderungsprofil der Gefäßchirurgie angepasst werden. Das elektromagnetische Instrumenten-Tracking erscheint als sinnvolle, komplementäre Technologie zur Umsetzung der MR-assistierten Navigation.

Evaluation of optical tracking and augmented reality for needle navigation in sacral nerve stimulation

BACKGROUND AND OBJECTIVE

Sacral nerve stimulation (SNS) is a minimally invasive procedure where an electrode lead is implanted through the sacral foramina to stimulate the nerve modulating colonic and urinary functions. One of the most crucial steps in SNS procedures is the placement of the tined lead close to the sacral nerve. However, needle insertion is very challenging for surgeons. Several x-ray projections are required to interpret the needle position correctly. In many cases, multiple punctures are needed, causing an increase in surgical time and patient's discomfort and pain. In this work we propose and evaluate two different navigation systems to guide electrode placement in SNS surgeries designed to reduce surgical time, minimize patient discomfort and improve surgical outcomes.

METHODS

We developed, for the first alternative, an open-source navigation software to guide electrode placement by real-time needle tracking with an optical tracking system (OTS). In the second method, we present a smartphone-based AR application that displays virtual guidance elements directly on the affected area, using a 3D printed reference marker placed on the patient. This guidance facilitates needle insertion with a predefined trajectory. Both techniques were evaluated to determine which one obtained better results than the current surgical procedure. To compare the proposals with the clinical method, we developed an x-ray software tool that calculates a digitally reconstructed radiograph, simulating the fluoroscopy acquisitions during the procedure. Twelve physicians (inexperienced and experienced users) performed needle insertions through several specific targets to evaluate the alternative SNS guidance methods on a realistic patient-based phantom.

RESULTS

With each navigation solution, we observed that users took less average time to complete each insertion (36.83 s and 44.43 s for the OTS and AR methods, respectively) and needed fewer average punctures to reach the target (1.23 and 1.96 for the OTS and AR methods respectively) than following the standard clinical method (189.28 s and 3.65 punctures).

CONCLUSIONS

To conclude, we have shown two navigation alternatives that could improve surgical outcome by significantly reducing needle insertions, surgical time and patient's pain in SNS procedures. We believe that these solutions are feasible to train surgeons and even replace current SNS clinical procedures.

Augmenting Performance: A Systematic Review of Optical See-Through Head-Mounted Displays in Surgery

We conducted a systematic review of recent literature to understand the current challenges in the use of optical see-through head-mounted displays (OST-HMDs) for augmented reality (AR) assisted surgery. Using Google Scholar, 57 relevant articles from 1 January 2021 through 18 March 2022 were identified. Selected articles were then categorized based on a taxonomy that described the required components of an effective AR-based navigation system: data, processing, overlay, view, and validation. Our findings indicated a focus on orthopedic (n=20) and maxillofacial surgeries (n=8). For preoperative input data, computed tomography (CT) (n=34), and surface rendered models (n=39) were most commonly used to represent image information. Virtual content was commonly directly superimposed with the target site (n=47); this was achieved by surface tracking of fiducials (n=30), external tracking (n=16), or manual placement (n=11). Microsoft HoloLens devices (n=24 in 2021, n=7 in 2022) were the most frequently used OST-HMDs; gestures and/or voice (n=32) served as the preferred interaction paradigm. Though promising system accuracy in the order of 2–5 mm has been demonstrated in phantom models, several human factors and technical challenges—perception, ease of use, context, interaction, and occlusion—remain to be addressed prior to widespread adoption of OST-HMD led surgical navigation.