A comparison of conventional and advanced 3D imaging techniques for percutaneous left atrial appendage closure.

Background: Understanding complex cardiac anatomy is essential for percutaneous left atrial appendage (LAA) closure. Conventional multi-slice computed tomography (MSCT) and transesophageal echocardiography (TEE) are now supported by advanced 3D printing and virtual reality (VR) techniques for three-dimensional visualization of volumetric data sets. This study aimed to investigate their added value for LAA closure procedures. Methods: Ten patients scheduled for interventional LAA closure were evaluated with MSCT and TEE. Patient-specific 3D printings and VR models were fabricated based on MSCT data. Ten cardiologists then comparatively assessed LAA anatomy and its procedure relevant surrounding structures with all four imaging modalities and rated their procedural utility on a 5-point Likert scale questionnaire (from 1 = strongly agree to 5 = strongly disagree). Results: Device sizing was rated highest in MSCT (MSCT: 1.9 ± 0.8; TEE: 2.6 ± 0.9; 3D printing: 2.5 ± 1.0; VR: 2.5 ± 1.1; p < 0.01); TEE, VR, and 3D printing were superior in the visualization of the Fossa ovalis compared to MSCT (MSCT: 3.3 ± 1.4; TEE: 2.2 ± 1.3; 3D printing: 2.2 ± 1.4; VR: 1.9 ± 1.3; all p < 0.01). The major strength of VR and 3D printing techniques was a superior depth perception (VR: 1.6 ± 0.5; 3D printing: 1.8 ± 0.4; TEE: 2.9 ± 0.7; MSCT: 2.6 ± 0.8; p < 0.01). The visualization of extracardiac structures was rated less accurate in TEE than MSCT (TEE: 2.6 ± 0.9; MSCT: 1.9 ± 0.8, p < 0.01). However, 3D printing and VR insufficiently visualized extracardiac structures in the present study. Conclusion: A true 3D visualization in VR or 3D printing provides an additional value in the evaluation of the LAA for the planning of percutaneous closure. In particular, the superior perception of depth was seen as a strength of a 3D visualization. This may contribute to a better overall understanding of the anatomy. Clinical studies are needed to evaluate whether a more comprehensive understanding through advanced multimodal imaging of patient-specific anatomy using VR may translate into improved procedural outcomes.

Echocardiographic-Fluoroscopic Fusion Imaging Improves Interventionalists' Learning Curve for Percutaneous Left Atrial Appendage Closure-Initial, Single-Center, Retrospective Observations.

Due to the complex and variable anatomy of the left atrial appendage, percutaneous left atrial appendage closure (LAAC) can be challenging. In this study, we investigated the impact of fusion imaging (FI) on the LAAC learning curve of two interventionalists. The first interventionalist (IC 1) was initially trained without FI and continued his training with FI. The second interventionalist (IC 2) performed all procedures with FI. We compared the first 36 procedures without FI of IC 1 (group 1) with his next 36 interventions with FI (group 2). Furthermore, group 1 was compared to 36 procedures of IC 2 who directly started his training with FI (group 3). Group 1 demonstrated that the learning curve without FI has a flat course with weak correlations for fluoroscopy time, contrast volume, and procedure time, but not for dose area product. Group 2 with FI showed improvement with a steep course and strong correlations for all four parameters. In group 3, we also saw a steep progression with strong correlations. Furthermore, the mean measurements of the parameters in the groups with FI decreased significantly as an indicator of procedural efficacy. We demonstrated that FI may improve the learning curve of experienced and non-experienced ICs.

Left atrial appendage sizing for percutaneous closure in virtual reality-a feasibility study.

Background and aims: The complex and highly variable three-dimensional anatomy of the left atrial appendage (LAA) makes planning and device sizing for interventional occlusion procedures (LAAC) challenging. Several imaging modalities [e.g. echocardiography, multi-slice computed tomography (MSCT)] are used for this purpose. Virtual reality (VR) is an emerging imaging technique to immerse into a three-dimensional left atrium and appendage, offering unprecedented options of visualization and measurement. This study aimed to investigate the feasibility, accuracy and reproducibility of visualizing the LAA in VR for preprocedural planning of LAAC. Methods and results: Twenty-one patients (79 ± 7 years, 62% male) who underwent LAAC at University Hospital Düsseldorf were included in our study. A dedicated software generated three-dimensional VR models from preprocedural MSCT imaging data. Conventional measurements of LAA dimensions (ostium, landing zone and depth) using a commercially available software were compared to measurements in VR: MSCT and VR ostium min. (r = 0.93), max. (r = 0.80) and mean (r = 0.88, all p < 0.001) diameters as well as landing zone (LZ) min. (r = 0.84), max. (r = 0.86) and mean diameters (r = 0.90, all p < 0.001) showed strong correlations. Three-dimensional orientation was judged superior by physicians in VR compared to MSCT (p < 0.05). Conclusion: Virtual reality visualization of the left atrium and appendage based on MSCT data is feasible and allows precise and reproducible measurements in planning of LAA occlusion procedures with enhanced 3D orientation. Further studies need to explore additional benefits of three-dimensional visualization for operators in preprocedural planning.

Virtual and augmented reality in intensive care medicine: a systematic review.

BACKGROUND: Virtual reality (VR) and augmented reality (AR) are rapidly developing technologies that offer a wide range of applications and enable users to experience digitally rendered content in both physical and virtual space. Although the number of studies about the different use of VR and AR increases year by year, a systematic overview of the applications of these innovative technologies in intensive care medicine is lacking. The aim of this systematic review was to provide a detailed summary of how VR and AR are currently being used in various areas of intensive care medicine. METHODS: We systematically searched PubMed until 1st March 2023 to identify the currently existing evidence for different applications of VR and AR for both health care providers in the intensive care unit and children or adults, who were in an intensive care unit because of a critical illness. RESULTS: After screening the literature, a total of 59 studies were included. Of note, a substantial number of publications consists of case reports, study plans or are lacking a control group. Furthermore, study designs are seldom comparable. However, there have been a variety of use cases for VR and AR that researchers have explored. They can help intensive care unit (ICU) personnel train, plan, and perform difficult procedures such as cardiopulmonary resuscitation, vascular punctures, endotracheal intubation or percutaneous dilatational tracheostomy. Patients might benefit from VR during invasive interventions and ICU stay by alleviating stress or pain. Furthermore, it enables contact with relatives and can also assist patients in their rehabilitation programs. CONCLUSION: Both, VR and AR, offer multiple possibilities to improve current care, both from the perspective of the healthcare professional and the patient. It can be assumed that VR and AR will develop further and their application in health care will increase.

Optimal Antithrombotic Regimen in Left Atrial Appendage Occlusion: The Gordian Knot?

Percutaneous left atrial appendage occlusion (LAAO) is an option to reduce the risk of stroke in patients with atrial fibrillation and high bleeding risk. However, device-related thrombosis (DRT) post LAAO is feared as complication. Simard et al. found a very high incidence of DRT compared to other trials. However, antithrombotic regimen and used devices have not been compared between studies. We compared DRT formation, antithrombotic regimen and used device in the recent DRT study, the Amplatzer IDE trial, and the Düsseldorf (DUS) LAAO registry. Occluder thrombosis occurred in 25.3% in the DRT study, 3.8% in the Amulet IDE trial, and 3.3% in the DUS LAAO registry (p < 0.0001). Oral anticoagulation-based regimen was more frequent in the DRT study compared to the DUS LAAO registry, whereas dual antiplatelet regimen was more frequent in the DUS LAAO registry (p < 0.0001). Amplatzer amulet was more frequently used in the DUS LAAO registry as compared to the DRT study (p < 0.0001). DRT is a feared complication after LAAO and seems to be dependent on antiplatelet treatment and underlying device. A clinical study controlling for device and antithrombotic regimen is needed to smash this Gordian knot.

The MRI posterior drawer test to assess posterior cruciate ligament functionality and knee joint laxity.

Clinical Magnetic Resonance Imaging (MRI) of joints is limited to mere morphologic evaluation and fails to directly visualize joint or ligament function. In this controlled laboratory study, we show that knee joint functionality may be quantified in situ and as a function of graded posterior cruciate ligament (PCL)-deficiency by combining MRI and standardized loading. 11 human knee joints underwent MRI under standardized posterior loading in the unloaded and loaded (147 N) configurations and in the intact, partially, and completely PCL-injured conditions. For each specimen, configuration, and condition, 3D joint models were implemented to analyse joint kinematics based on 3D Euclidean vectors and their projections on the Cartesian planes. Manual 2D measurements served as reference. With increasing PCL deficiency, vector projections increased significantly in the anteroposterior dimension under loading and manual measurements demonstrated similar patterns of change. Consequently, if combined with advanced image post-processing, stress MRI is a powerful diagnostic adjunct to evaluate ligament functionality and joint laxity in multiple dimensions and may have a role in differentiating PCL injury patterns, therapeutic decision-making, and treatment monitoring.

Real-time echocardiography-fluoroscopy fusion imaging for left atrial appendage closure: prime time for fusion imaging?

BACKGROUND: Real-time echocardiography-fluoroscopy fusion imaging (FI) merges real-time echocardiographic imaging with fluoroscopic images allowing intuitive anatomical spatial orientation during structural heart disease interventions. We aimed to assess the safety and efficacy of FI during percutaneous left atrial appendage closure (LAAC). METHODS: 34 consecutive patients before (-FI) and 121 patients after (+FI) the introduction of FI for LAAC were included in a single-centre study. In-hospital safety parameters were analysed according to adverse event (AE) definition of the Munich consensus document and procedure-related parameters were assessed for efficacy. An ANCOVA was performed to investigate the influence of a learning curve. RESULTS: Time until successful transseptal puncture was significantly reduced as well as total procedure time and the amount of contrast agent used (+FI/-FI:17 ± 6.35 min vs. 22 ± 8.33 min, p = 0.001; +FI/-FI: 50 min IQR 43 min - 60 min vs. 57 min IQR 45 min -70 min; p = 0.013; +FI/-FI: 70 mL, IQR 55 ml-90 mL vs. 152 mL, IQR 107 mL - 205 mL; p < 0.001). However, fluoroscopy time and dose-area product did not differ between both groups. There was no significant difference in the occurrence of in-hospital adverse events (+FI/-FI: 2.5% vs. 0%; p = 0.596). The ANCOVA revealed that the learning curve does not affect procedural efficacy parameters such as procedure time, time to transseptal puncture, amount of contrast agent and dose-area product. CONCLUSIONS: FI for LAAC reduces the total procedure time, the time to successful transseptal puncture and periprocedural amount of contrast agent.