Three-Dimensional Reconstruction of Intracardiac Anatomy Using CTA and Surgical Planning for Double Outlet Right Ventricle: Early Experience at a Tertiary Care Congenital Heart Center

3D modeling and printing for complex biventricular repair of double outlet right ventricle

BACKGROUND

Double outlet right ventricle (DORV) describes a group of congenital heart defects where pulmonary artery and aorta originate completely or predominantly from the right ventricle. The individual anatomy of DORV patients varies widely with multiple subtypes classified. Although the majority of morphologies is suitable for biventricular repair (BVR), complex DORV anatomy can render univentricular palliation (UVP) the only option. Thus, patient-specific decision-making is critical for optimal surgical treatment planning. The evolution of image processing and rapid prototyping techniques facilitate the generation of detailed virtual and physical 3D models of the patient-specific anatomy which can support this important decision process within the Heart Team.

MATERILAS AND METHODS

The individual cardiovascular anatomy of nine patients with complex DORV, in whom surgical decision-making was not straightforward, was reconstructed from either computed tomography or magnetic resonance imaging data. 3D reconstructions were used to characterize the morphologic details of DORV, such as size and location of the ventricular septal defect (VSD), atrioventricular valve size, ventricular volumes, relationship between the great arteries and their spatial relation to the VSD, outflow tract obstructions, coronary artery anatomy, etc. Additionally, physical models were generated. Virtual and physical models were used in the preoperative assessment to determine surgical treatment strategy, either BVR vs. UVP.

RESULTS

Median age at operation was 13.2 months (IQR: 9.6-24.0). The DORV transposition subtype was present in six patients, three patients had a DORV-ventricular septal defect subtype. Patient-specific reconstruction was feasible for all patients despite heterogeneous image quality. Complex BVR was feasible in 5/9 patients (55%). Reasons for unsuitability for BVR were AV valve chordae interfering with potential intraventricular baffle creation, ventricular hypoplasia and non-committed VSD morphology. Evaluation in particular of qualitative data from 3D models was considered to support comprehension of complex anatomy.

CONCLUSION

Image-based 3D reconstruction of patient-specific intracardiac anatomy provides valuable additional information supporting decision-making processes and surgical planning in complex cardiac malformations. Further prospective studies are required to fully appreciate the benefits of 3D technology.

Double outlet right ventricle in adults: Anatomic variability, surgical treatment, and late postoperative complications

Double outlet right ventricle (DORV) is a highly complex congenital heart disease (CHD) entity, gaining increasing interest due to the rapid progress of cardiac surgery. The number of patients operated for this congenital defect has been growing since 1980s and over following decades with active transitioning of this cohort into the adult medicine. However, the diversity of initial anomaly and performed interventions makes challenging the management of these patients. This is particularly important in the regions where specialized adult CHD cardiology still remains underdeveloped. In this review, we observe the basic principles of DORV nomenclature, main types of the operations and possible late complications. The article focuses on adult patients and offers illustrations from clinical practice.

Double Outlet Right Ventricle: In-Depth Anatomic Review Using Three-Dimensional Cardiac CT Data

Double outlet right ventricle (DORV) is a relatively common congenital heart disease in which both great arteries are connected completely or predominantly to the morphologic RV. Unlike other congenital heart diseases, DORV demonstrates various anatomic and hemodynamic subtypes, mimicking ventricular septal defect, tetralogy of Fallot, transposition of the great arteries, and functional single ventricle. Because different surgical strategies are applied to different subtypes of DORV with ventricular septal defects, a detailed assessment of intracardiac anatomy should be performed preoperatively. Due to high spatial and contrast resolutions, cardiac CT can provide an accurate characterization of various intracardiac morphologic features of DORV. In this pictorial essay, major anatomic factors affecting surgical decision-making in DORV with ventricular septal defects were comprehensively reviewed using three-dimensional cardiac CT data. In addition, the surgical procedures available for these patients and major postoperative complications are described.

Pediatric Cardiothoracic CT Guideline Provided by the Asian Society of Cardiovascular Imaging Congenital Heart Disease Study Group: Part 2. Contemporary Clinical Applications

The use of pediatric cardiothoracic CT for congenital heart disease (CHD) was traditionally limited to the morphologic evaluation of the extracardiac thoracic vessels, lungs, and airways. Currently, the applications of CT have increased, owing to technological advancements in hardware and software as well as several dose-reduction measures. In the previously published part 1 of the guideline by the Asian Society of Cardiovascular Imaging Congenital Heart Disease Study Group, we reviewed the prerequisite technical knowledge for clinical applications in a user-friendly and vendor-specific manner. Herein, we present the second part of our guideline on contemporary clinical applications of pediatric cardiothoracic CT for CHD based on the consensus of experts from the Asian Society of Cardiovascular Imaging CHD Study Group. This guideline describes up-to-date clinical applications effectively in a systematic fashion.

[Impact of 3D printing in surgical planning of congenital heart disease]

Introducción

Los defectos cardíacos congénitos constituyen el 30% de todas las anomalías congénitas. La prevalencia es de 8/1,000 recién nacidos vivos, sin predominio de género. Para una planificación quirúrgica óptima es esencial una evaluación precisa de la anatomía en los defectos cardíacos congénitos. Las modalidades de imagen como el ecocardiograma, la angiografía por cateterismo cardíaco, la tomografía computarizada (TC) o la resonancia magnética (RM) se utilizan de forma regular para el diagnóstico de las cardiopatías congénitas. Estos métodos pueden proporcionar reconstrucciones virtuales en reconstrucción volumétrica o 3D, pero no réplicas táctiles reales de la anatomía cardíaca.

Objetivo

Realizar modelos de corazón impresos en 3D con la finalidad de proporcionar réplicas táctiles 3D reales de la anatomía cardíaca para visualizar de forma detallada todas las perspectivas posibles de las estructuras extracardíacas o intracardíacas.

Métodos

Los datos de la imagen se obtuvieron en formato DICOM, se editaron en el paquete de software "3D slicer 4.3" y se exportaron para la impresión en formato de archivo (.stl).

Resultados y conclusiones

Con la impresión 3D se puede evaluar de forma detallada la anatomía intracardíaca y extracardíaca con modelos cardíacos en tiempo real. Esta técnica es de gran utilidad, sobre todo en los defectos cardíacos congénitos complejos, ya que permite hacer una planificación precisa del procedimiento quirúrgico.

Introduction

Congenital heart disease makes up for 30% of all congenital anomalies. The prevalence is 8/1,000 live newborns, without predominance of gender. Imaging methods such as echocardiography, angiography, computed tomography or magnetic resonance imaging must be routinely used in congenital heart disease. The mentioned methods can provide virtual reconstructions in volumetric reconstruction or in three dimensional (3D), but only 3D-printed heart models can provide real 3D tactile replicas of cardiac anatomy.

Objective

To make 3D printed heart models in order to provide real 3D tactile replicas of the cardiac anatomy that allow a detailed visualization from all possible perspectives, either of extracardiac or intracardiac structures.

Methods

This information is useful for surgical decision making, especially in patients with complex cardiac defects. DICOM, edited in a software package “3D slicer 4.3” and exported for printing in file format (.stl).

Results and conclusions

With 3D printing, the intracardiac and extracardiac anatomy can be evaluated in detail with real-scale cardiac models of the patient, avoiding unexpected findings. This technique is very useful especially in complex congenital heart defects, since it allows precise planning of the surgical procedure.

Narrative review of assessing the surgical options for double outlet right ventricle

The individualized surgical approach in individuals with both arterial trunks arising from the morphologically right ventricle is dictated by the extreme morphological variability encountered in this setting, with each patient being unique. An individualized surgical approach has been designed to take account of the morphological variations, identifying the anatomy with the preoperative three-dimensional CT scan reconstruction. The key features have been considered the distance between tricuspid and pulmonary valves, the size and location of the interventricular communication, and the relationship between the outflow tracts. The surgical approach is tailored, whenever feasible, to create a connection between left ventricle and aorta, but primarily to achieve biventricular repair. Account has been taken of all available surgical options already reported in the literature, identifying the most suitable to provide the best outcomes for each unique morphology. To date, meaningful comparison between different reported surgical series has been difficult because of the marked variation of individual intracardiac morphology, and the lack of reports of specific surgical approaches for well-categorized groups of patients. Our approach, being tailored to the individual cardiac morphology, can be offered to any patient with this ventriculo-arterial connection. Given the difficulties of diagnosis, and the multiple therapeutic indications, very close collaboration between cardiologists and surgeons is indispensable for further progress in the understanding and management of this complex congenital cardiac lesion.

Utility of a super-flexible three-dimensional printed heart model in congenital heart surgery

OBJECTIVES

The objective of this study was to assess the utility of 3D printed heart models of congenital heart disease for preoperative surgical simulation.

METHODS

Twenty patient-specific 3D models were created between March 2015 and August 2017. All operations were performed by a young consultant surgeon who had no prior experience with complex biventricular repair. All 15 patients with balanced ventricles had outflow tract malformations (double-outlet right ventricle in 7 patients, congenitally corrected transposition of great arteries in 5, transposition of great arteries in 1, interrupted aortic arch Type B in 1, tetralogy of Fallot with pulmonary atresia and major aortopulmonary collateral arteries in 1). One patient had hypoplastic left heart complex, and the remaining 4 patients had a functional single ventricle. The median age at operation was 1.4 (range 0.1-5.9) years. Based on a multislice computed tomography data set, the 3D models were made of polyurethane resins using stereolithography as the printing technology and vacuum casting as the manufacturing method.

RESULTS

All but 4 patients with a functional single ventricle underwent complete biventricular repair. The median cardiopulmonary bypass time and aortic cross-clamp time were 345 (110-570) min and 114 (35-293) min, respectively. During the median follow-up period of 1.3 (0.1-2.5) years, no mortality was observed. None of the patients experienced surgical heart block or systemic ventricular outflow tract obstruction.

CONCLUSIONS

Three-dimensional printed heart models showed potential utility, especially in understanding the relationship between intraventricular communications and great vessels, as well as in simulation for creating intracardiac pathways.

3D modeling: a future of cardiovascular medicine

Cardiovascular disease resulting from atypical cardiac structures continues to be a leading health concern despite advancements in diagnostic imaging and surgical techniques. However, the ability to visualize spatial relationships using current technologies remains a challenge. Therefore, 3D modeling has gained significant interest to understand complex and atypical cardiovascular disorders. Moreover, 3D modeling can be personalized and patient-specific. 3D models have been demonstrated to aid surgical planning and simulation, enhance communication among surgeons and patients, optimize medical device design, and can be used as a potential teaching tool in medical schools. In this review, we discuss the key components needed to generate cardiac 3D models. We highlight prevalent structural conditions that have utilized 3D modeling in pre-operative planning. Furthermore, we discuss the current limitations of routine use of 3D models in the clinic as well as future directions for utilization of this technology in the cardiovascular field.

Radiological Society of North America (RSNA) 3D printing Special Interest Group (SIG): guidelines for medical 3D printing and appropriateness for clinical scenarios

Medical three-dimensional (3D) printing has expanded dramatically over the past three decades with growth in both facility adoption and the variety of medical applications. Consideration for each step required to create accurate 3D printed models from medical imaging data impacts patient care and management. In this paper, a writing group representing the Radiological Society of North America Special Interest Group on 3D Printing (SIG) provides recommendations that have been vetted and voted on by the SIG active membership. This body of work includes appropriate clinical use of anatomic models 3D printed for diagnostic use in the care of patients with specific medical conditions. The recommendations provide guidance for approaches and tools in medical 3D printing, from image acquisition, segmentation of the desired anatomy intended for 3D printing, creation of a 3D-printable model, and post-processing of 3D printed anatomic models for patient care.

Right Heart-Pulmonary Circulation Unit in Congenital Heart Diseases

The right ventricle plays a major role in congenital heart disease. This article describes the right ventricular mechanics in some selected congenital heart diseases affecting the right ventricle in different ways: tetralogy of Fallot, Ebstein anomaly, and the systemic right ventricle.

Virtual medicine: Utilization of the advanced cardiac imaging patient avatar for procedural planning and facilitation

Advances in imaging technology have led to a paradigm shift from planning of cardiovascular procedures and surgeries requiring the actual patient in a "brick and mortar" hospital to utilization of the digitalized patient in the virtual hospital. Cardiovascular computed tomographic angiography (CCTA) and cardiovascular magnetic resonance (CMR) digitalized 3-D patient representation of individual patient anatomy and physiology serves as an avatar allowing for virtual delineation of the most optimal approaches to cardiovascular procedures and surgeries prior to actual hospitalization. Pre-hospitalization reconstruction and analysis of anatomy and pathophysiology previously only accessible during the actual procedure could potentially limit the intrinsic risks related to time in the operating room, cardiac procedural laboratory and overall hospital environment. Although applications are specific to areas of cardiovascular specialty focus, there are unifying themes related to the utilization of technologies. The virtual patient avatar computer can also be used for procedural planning, computational modeling of anatomy, simulation of predicted therapeutic result, printing of 3-D models, and augmentation of real time procedural performance. Examples of the above techniques are at various stages of development for application to the spectrum of cardiovascular disease processes, including percutaneous, surgical and hybrid minimally invasive interventions. A multidisciplinary approach within medicine and engineering is necessary for creation of robust algorithms for maximal utilization of the virtual patient avatar in the digital medical center. Utilization of the virtual advanced cardiac imaging patient avatar will play an important role in the virtual health care system. Although there has been a rapid proliferation of early data, advanced imaging applications require further assessment and validation of accuracy, reproducibility, standardization, safety, efficacy, quality, cost effectiveness, and overall value to medical care.

Virtual Surgery for Conduit Reconstruction of the Right Ventricular Outflow Tract

PURPOSE

Virtual surgery involves the planning and simulation of surgical reconstruction using three-dimensional (3D) modeling based upon individual patient data, augmented by simulation of planned surgical alterations including implantation of devices or grafts. Here we describe a case in which virtual cardiac surgery aided us in determining the optimal conduit size to use for the reconstruction of the right ventricular outflow tract.

DESCRIPTION

The patient is a young adolescent male with a history of tetralogy of Fallot with pulmonary atresia, requiring right ventricle-to-pulmonary artery (RV-PA) conduit replacement. Utilizing preoperative magnetic resonance imaging data, virtual surgery was undertaken to construct his heart in 3D and to simulate the implantation of three different sizes of RV-PA conduit (18, 20, and 22 mm).

EVALUATION

Virtual cardiac surgery allowed us to predict the ability to implant a conduit of a size that would likely remain adequate in the face of continued somatic growth and also allow for the possibility of transcatheter pulmonary valve implantation at some time in the future. Subsequently, the patient underwent uneventful conduit change surgery with implantation of a 22-mm Hancock valved conduit. As predicted, the intrathoracic space was sufficient to accommodate the relatively large conduit size without geometric distortion or sternal compression.

CONCLUSION

Virtual cardiac surgery gives surgeons the ability to simulate the implantation of prostheses of different sizes in relation to the dimensions of a specific patient's own heart and thoracic cavity in 3D prior to surgery. This can be very helpful in predicting optimal conduit size, determining appropriate timing of surgery, and patient education.