Usefulness of echocardiographic-fluoroscopic fusion imaging in children with congenital heart disease

Advancing paediatric cardiac imaging: a comprehensive analysis of the feasibility and accuracy of a novel 3D paediatric transoesophageal probe

Aims

Pediatric transoesophageal echocardiography (TOE) probes have remained two-dimensional (2D) limiting their use compared to adults. While critical in pediatrics for interventions and post-surgery assessments, technological advancements introduced a three-dimensional (3D) pediatric TOE probe. This study assessed the new 3D pediatric TOE probe (GE 9VT-D) for feasibility, handling, and imaging quality.

Methods and results

At Children's Hospital of Toulouse, 2-month prospective study enrolled children undergoing TOE with the new probe. All imaging modalities were rated by 2 operators using a 5-point Likert-type scale from 1 (very poor) to 5 (very good) quality. Forty-five children, median age 3.7 (range: 2 months-14.7 years) median weight 7.8 kg (range: 4.3-48 kg) underwent 60 TOEs: 25% pre-surgery, 45% post-surgery, 28% during percutaneous procedures, and 2% in intensive care. Probe handling was "very easy" in all cases without adverse events. The median score of 2D, 2D colour, pulsed Doppler and 3D were noted 5 out of 5 and continuous Doppler and 3D colour 4 out of 5. The 3D image quality remained consistent irrespective of the patient weighing above or below 7.8 kg (p = 0.72). Postoperative TOEs identified two cases needing further interventions, emphasizing its value in evaluating surgical outcomes and also for guiding percutaneous interventions.

Conclusion

Our comprehensive evaluation demonstrates that the new 3D pediatric TOE probe is feasible and provides high-quality imaging in pediatric patients. The successful integration of this novel probe into clinical practice has the potential to enhance diagnostic accuracy and procedural planning, ultimately optimizing patient outcomes in pediatric cardiac care.

Multi-modality cardiac image computing: A survey

Multi-modality cardiac imaging plays a key role in the management of patients with cardiovascular diseases. It allows a combination of complementary anatomical, morphological and functional information, increases diagnosis accuracy, and improves the efficacy of cardiovascular interventions and clinical outcomes. Fully-automated processing and quantitative analysis of multi-modality cardiac images could have a direct impact on clinical research and evidence-based patient management. However, these require overcoming significant challenges including inter-modality misalignment and finding optimal methods to integrate information from different modalities. This paper aims to provide a comprehensive review of multi-modality imaging in cardiology, the computing methods, the validation strategies, the related clinical workflows and future perspectives. For the computing methodologies, we have a favored focus on the three tasks, i.e., registration, fusion and segmentation, which generally involve multi-modality imaging data, either combining information from different modalities or transferring information across modalities. The review highlights that multi-modality cardiac imaging data has the potential of wide applicability in the clinic, such as trans-aortic valve implantation guidance, myocardial viability assessment, and catheter ablation therapy and its patient selection. Nevertheless, many challenges remain unsolved, such as missing modality, modality selection, combination of imaging and non-imaging data, and uniform analysis and representation of different modalities. There is also work to do in defining how the well-developed techniques fit in clinical workflows and how much additional and relevant information they introduce. These problems are likely to continue to be an active field of research and the questions to be answered in the future.

Procedural Software Toolkit in the Armamentarium of Interventional Therapies: A Review of Additive Usefulness and Current Evidence

Interventional radiology is a fast-paced specialty that uses many advanced and emerging technological solutions. Several procedural hardware and software products are available commercially. Image-guided procedural software helps save time and effort in interventionist practice and adds precision to the intraoperative decisions made by the end user. Interventional radiologists, including interventional oncologists, have access to a wide range of commercially available procedural software that can be integrated into their workflow. However, the resources and real-world evidence related to such software are limited. Thus, we performed a detailed review of the current resources available, such as software-related publications, vendors' multimedia materials (e.g., user guides), and each software's functions and features, to compile a resource for interventional therapies. We also reviewed previous studies that have verified the use of such software in angiographic suites. Procedural software products will continue to increase in number and usage; these will likely be advanced further with deep learning, artificial intelligence, and new add-ins. Therefore, classifying procedural product software can improve our understanding of these entities. This review significantly contributes to the existing literature because it highlights the lack of studies on procedural product software.

3D Approaches in Complex CHD: Where Are We? Funny Printing and Beautiful Images, or a Useful Tool?

Echocardiography, CT and MRI have a crucial role in the management of congenital heart disease (CHD) patients. All of these modalities can be presented in a 2D or a 3D rendered format. The aim of this paper is to review the key advantages and potential limitations, as well as the future challenges of a 3D approach in each imaging modality. The focus of this review is on anatomic rather than functional assessment. Conventional 2D echocardiography presents limitations when imaging complex lesions, whereas 3D imaging depicts the anatomy in all dimensions. CT and MRI can visualise extracardiac vasculature and guide complex biventricular repair. Three-dimensional printed models can be used in depicting complex intracardiac relationships and defining the surgical strategy in specific lesions. Extended reality imaging retained dynamic cardiac motion holds great potential for planning surgical and catheter procedures. Overall, the use of 3D imaging has resulted in a better understanding of anatomy, with a direct impact on the surgical and catheter approach, particularly in more complex cases.

Intracardiac Echocardiogram: Feasibility, Efficacy, and Safety for Guidance of Transcatheter Multiple Atrial Septal Defects Closure

We aimed to determine the feasibility, efficacy, success, and safety of intracardiac echocardiography (ICE) in transcatheter multiple atrial septal defect (ASD) closure. Of 185 patients with multiple ASDs who underwent transcatheter closure, 140 (76%) patients who weighed <30kg with a narrow distance between defects or in whom single device closure was anticipated were guided by ICE and 45 patients were guided by three-dimensional (3D) transesophageal echocardiography (TEE) with or without ICE. Patients in the ICE group were relatively younger and weighed less than those in the 3D TEE group (p < 0.0001). The ratio of the distance between defects >7 mm was high, and more cases required ≥2 devices in the 3D TEE group than those in the ICE group (p < 0.0001). All patients in the 3D TEE group and seven patients (5%) in the ICE group were operated on under general anesthesia (p < 0.0001). The fluoroscopic time was shorter in the ICE group (13.98 ± 6.24 min vs. 24.86 ± 16.47 min, p = 0.0005). No difference in the complete closure rate and complications was observed. ICE-guided transcatheter and 3D TEE were feasible, safe, and effective in successful multiple ASD device closures, especially for young children and patients at high risk under general anesthesia.

Transcatheter Device Therapy and the Integration of Advanced Imaging in Congenital Heart Disease

Transcatheter device intervention is now offered as first line therapy for many congenital heart defects (CHD) which were traditionally treated with cardiac surgery. While off-label use of devices is common and appropriate, a growing number of devices are now specifically designed and approved for use in CHD. Advanced imaging is now an integral part of interventional procedures including pre-procedure planning, intra-procedural guidance, and post-procedure monitoring. There is robust societal and industrial support for research and development of CHD-specific devices, and the regulatory framework at the national and international level is patient friendly. It is against this backdrop that we review transcatheter implantable devices for CHD, the role and integration of advanced imaging, and explore the current regulatory framework for device approval.

Renaissance of Cardiac Imaging to Assist Percutaneous Interventions in Congenital Heart Diseases:The Role of Three-Dimensional Echocardiography and Multimodality Imaging

Percutaneous interventions have completely refashioned the management of children with congenital heart diseases (CHD) and the use of non-invasive imaging has become the gold standard to plan and guide these procedures in the modern era. We are now facing a dual challenge to improve the standard of care in low-risk patients, and to shift our strategies from the classic open chest surgery to imaging-guided percutaneous interventions in high-risk patients. Such rapid evolution of ultrasound technologies over the last 20 years have permitted the integration of transthoracic, transesophageal and intracardiac echocardiography into the interventional workflow to improve image guidance and reduce radiation burden from fluoroscopy and angiography. Specifically, miniaturization of transesophageal probe and advances in three-dimensional (3D) imaging techniques have enabled real-time 3D image guidance during complex interventional procedure, In addition, multimodality and fusion imaging techniques harness the strengths of different modalities to enhance understanding of anatomical and spatial relationship between different structures, improving communication and coordination between interventionalists and imaging specialists. In this review, we aim to provide an overview of 3D imaging modalities and multimodal fusion in procedural planning and live guidance of percutaneous interventions. At the present times, 3D imaging can no longer be considered a luxury but a routine clinical tool to improve procedural success and patient outcomes.

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.

Sinus Venosus ASDs: Imaging and Percutaneous Closure

PURPOSE OF THE REVIEW

Percutaneous closure of sinus venosus atrial septal defects (ASD) using covered stent implantation is a new and promising minimally invasive technique. New imaging tools are used to ensure preoperative anatomical characterization and preoperative guidance, which are key procedural success factors. Here we will describe and analyze these recent developments.

RECENT FINDINGS

Sinus venosus ASDs present a wide variety of anatomical features which must be described and analyzed using various imaging tools, including 3D technology. Percutaneous closure is challenging, but can hasten clinical recovery compared to the gold-standard conventional open-heart surgery. The feasibility of percutaneous closure relies on precise preoperative anatomical study and on real-time guidance using a multimodal fusion imaging process. Three-dimensional modeling of sinus venosus ASD is essential to understand the large anatomical panel encountered in this pathology. Multimodal fusion imaging guidance is very useful for performing sinus venosus ASD percutaneous closure in selected patients.

Fusion Imaging of X-ray and Transesophageal Echocardiography Improves the Procedure of Left Atrial Appendage Closure

BACKGROUND

Left atrial appendage closure (LAAC) is an alternative treatment strategy for patients with atrial fibrillation who are at risk for thromboembolic events and considered not suitable for oral anticoagulation (OAC). LAAC is mainly performed under the guidance of transesophageal echocardiography (TEE) and fluoroscopy. The study presented here should analyze whether fusion imaging (FI) of transesophageal echocardiography and X-ray performed during LAAC is feasible and can improve the results of the procedure.

METHODS

The data presented here are from a retrospective single center study. Sample size was defined as 50 patients in which LAAC was performed without fusion imaging (control group) and 25 patients were the LAAC procedure was guided by fusion imaging (treatment group). Inclusion criteria were defined as age > 18 years and completion of an LAAC procedure defined as deployment of a WATCHMAN 2.5 LAA occluder. Study endpoints were procedure time, amount of used contrast medium, radiation dose, final position of the WATCHMAN in TEE (deviation from ideal positioning), and clinical endpoints, respectively.

RESULTS

LAA closure was successfully performed in all patients. No case of device embolism was occurring, and none of the patients experienced a periprocedural stroke/TIA nor a systemic embolism, respectively. Mean procedure time was 15 min shorter in the group of patients where fusion imaging was applied (p < 0.001). Additionally, the use of fusion imaging was associated with a significant reduction of contrast medium (20.6 ml less than in control; p < 0.045). Regarding the final position of the WATCHMAN, no relevant differences were found between the groups. The use of fusion imaging significantly reduced procedure time and the amount of contrast medium in patients undergoing LAAC.

3D-XGuide: open-source X-ray navigation guidance system

PURPOSE

With the growing availability and variety of imaging modalities, new methods of intraoperative support have become available for all kinds of interventions. The basic principles of image fusion and image guidance have been widely adopted and are commercialized through a number of platforms. Although multimodal systems have been found to be useful for guiding interventional procedures, they all have their limitations. The integration of more advanced guidance techniques into the product functionality is, however, not easy due to the proprietary solutions of the vendors. Therefore, the purpose of this work is to introduce a software system for image fusion, real-time navigation, and working points documentation during transcatheter interventions performed under X-ray (XR) guidance.

METHODS

An interactive software system for cross-modal registration and image fusion of XR fluoroscopy with CT or MRI-derived anatomic 3D models is implemented using Qt application framework and VTK visualization pipeline. DICOM data can be imported in retrospective mode. Live XR data input is realized by a video capture card application interface.

RESULTS

The actual software release offers a graphical user interface with basic functionality including data import and handling, calculation of projection geometry and transformations between related coordinate systems, rigid 3D-3D registration, and template matching-based tracking and motion compensation algorithms in 2D and 3D. The link to the actual software release on GitHub including source code and executable is provided to support independent research and development in the field of intervention guidance.

CONCLUSION

The introduced system provides a common foundation for the rapid prototyping of new approaches in the field of XR fluoroscopic guidance. As a pure software solution, the developed system is potentially vendor-independent and can be easily extended to be used with the XR systems of different manufacturers.

Fusion imaging in interventional cardiology

The number and complexity of percutaneous interventions for the treatment of structural heart disease has increased in clinical practice in parallel with the development of new imaging technologies, in order to render these interventions safer and more accurate. Complementary imaging modalities are commonly used, but they require additional mental reconstruction and effort by the interventional team. The concept of fusion imaging, where two different modalities are fused in real time and on a single monitor, aims to solve these limitations. This is an important tool to guide percutaneous interventions, enabling a good visualization of catheters, guidewires and devices employed, with enhanced spatial resolution and anatomical definition. It also allows the marking of anatomical reference points of interest for the procedure. Some studies show decreased procedural time and total radiation dose with fusion imaging; however, there is a need to obtain data with more robust scientific methodology to assess the impact of this technology in clinical practice. The aim of this review is to describe the concept and basic principles of fusion imaging, its main clinical applications and some considerations about the promising future of this imaging technology.

Transcatheter closure of a perimembranous ventricular septal defect with Nit-Occlud Lê VSD Coil: A French multicentre study

BACKGROUND

Transcatheter perimembranous ventricular septal defect (pmVSD) closure remains challenging and is seldom used in France given the risk of atrioventricular block (AVB). pmVSD closure with the Nit-Occlud Lê VSD coil was recently introduced in France as an alternative to occluder devices.

AIMS

To study the safety and feasibility of pmVSD closure with the Nit-Occlud Lê VSD coil.

METHODS

All consecutives cases of pmVSD closure with the Nit-Occlud Lê VSD coil in 20 tertiary French centres were included between January 2015 and December 2018.

RESULTS

Among 46 procedures in five centres, indications for pmVSD closure were left ventricle overload (76.1%), exertional dyspnoea (17.4%), history of infective endocarditis (4.3%) and mild pulmonary hypertension (2.2%). The median (interquartile [IQR]) age of the patients was 13.9 (5.7-31.8) years. Aneurismal tissue was identified in 91.3% of patients. VSD median (IQR) size was 8 (7-10) mm on the left ventricle side and 5 (4-6) mm on the right ventricle side. Implantation was successful in 40 patients (87.0%; 95% confidence interval [CI] 73.7-95.1%). Severe complications occurred in six patients (13.0%, 95% CI 4.9-26.3%), mainly severe haemolysis (8.7%, 95% CI 2.4-20.8%). One aortic valve lesion required surgical aortic valvuloplasty. Occurrence of severe complications was significantly related to the presence of haemolysis (P=0.001), residual shunt (P=0.007) and multi-exit VSD (P=0.005). Residual shunt was observed in 40% of cases with the implanted device shortly after closure and 15% after a median follow-up of 27 months. No immediate or delayed device embolization or complete AVB was recorded.

CONCLUSION

pmVSD closure with the Nit-Occlud Lê VSD Coil is feasible in older children and adults. However, residual shunting (leading to haemolysis) is a dreaded complication that should not be tolerated. pmVSD closure with the Nit-Occlud Lê VSD as a therapeutic strategy remains controversial and is limited to selected patients.

X-ray fused with MRI guidance of pre-selected transcatheter congenital heart disease interventions

OBJECTIVES

To determine whether X-ray fused with MRI (XFM) is beneficial for select transcatheter congenital heart disease interventions.

BACKGROUND

Complex transcatheter interventions often require three-dimensional (3D) soft tissue imaging guidance. Fusion imaging with live X-ray fluoroscopy can potentially improve and simplify procedures.

METHODS

Patients referred for select congenital heart disease interventions were prospectively enrolled. Cardiac MRI data was overlaid on live fluoroscopy for procedural guidance. Likert scale operator assessments of value were recorded. Fluoroscopy time, radiation exposure, contrast dose, and procedure time were compared to matched cases from our institutional experience.

RESULTS

Forty-six patients were enrolled. Pre-catheterization, same day cardiac MRI findings indicated intervention should be deferred in nine patients. XFM-guided cardiac catheterization was performed in 37 (median age 8.7 years [0.5-63 years]; median weight 28 kg [5.6-110 kg]) with the following prespecified indications: pulmonary artery (PA) stenosis (n = 13), aortic coarctation (n = 12), conduit stenosis/insufficiency (n = 9), and ventricular septal defect (n = 3). Diagnostic catheterization showed intervention was not indicated in 12 additional cases. XFM-guided intervention was performed in the remaining 25. Fluoroscopy time was shorter for XFM-guided intervention cases compared to matched controls. There was no significant difference in radiation dose area product, contrast volume, or procedure time. Operator Likert scores indicated XFM provided useful soft tissue guidance in all cases and was never misleading.

CONCLUSIONS

XFM provides operators with meaningful three-dimensional soft tissue data and reduces fluoroscopy time in select congenital heart disease interventions.

EDUCATIONAL SERIES IN CONGENITAL HEART DISEASE: Three-dimensional echocardiography in congenital heart disease

Three-dimensional echocardiography is a valuable tool for the assessment of cardiac function where it permits calculation of chamber volume and function. The anatomy of valvar and septal structures can be presented in unique and intuitive ways to enhance surgical planning. Guidance of interventional procedures using the technique has now become established in many clinical settings. Enhancements of image processing to include intracavity flow, image fusion and true 3D displays look set to further improve the contribution of this modality to care of the patient with congenital heart disease.