Real-time three-dimensional transoesophageal echocardiography: a new intraoperative feasible and useful technology in cardiac surgery

Balloon mitral valvuloplasty: a re-emerging technique enhanced with real-time, three-dimensional transoesophageal cardiac ultrasound/echocardiography (3D-TOE)

We describe the case of a woman in her 60s with mitral stenosis, rate-controlled atrial fibrillation and a history of childhood rheumatic fever. She successfully underwent elective percutaneous transvenous mitral commissurotomy (PTMC), also described as balloon mitral valvuloplasty, for severe, symptomatic mitral stenosis. This was completed via right femoral vein access, trans-septal puncture and commissural separation guided by real-time three-dimensional (3D) transoesophageal echocardiography under general anaesthesia.Balloon mitral valvuloplasty is being completed more frequently in the UK due to the population having a higher incidence of mitral valve disease as a result of migration and as a palliative measure in those considered too high risk for mitral valve replacement cardiothoracic surgery.Rheumatic mitral stenosis is known to be a disease prevalent in countries of low and middle income and with increased migration to the UK, resulting in an increased prevalence of rheumatic mitral valve disease in the UK. It is estimated that within the UK, one in seven persons are migrants, and as such, we believe it is important to pay attention to diseases which affect the evolving population of the UK.Technological advancements, including availability and use of 3D transoesophageal cardiac ultrasound/echocardiography, have made PTMC much safer and more effective than previously. Additionally, the multidisciplinary team approach to PTMC is very important to its success. The procedure was completed successfully, with no complications.

3D echocardiography in mitral valve prolapse

Mitral valve prolapse (MVP) is the leading cause of mitral valve surgery. Echocardiography is the principal imaging modality used to diagnose MVP, assess the mitral valve morphology and mitral annulus dynamics, and quantify mitral regurgitation. Three-dimensional (3D) echocardiographic (3DE) imaging represents a consistent innovation in cardiovascular ultrasound in the last decades, and it has been implemented in routine clinical practice for the evaluation of mitral valve diseases. The focus of this review is the role and the advantages of 3DE in the comprehensive evaluation of MVP, intraoperative and intraprocedural monitoring.

Spatiotemporal registration of multiple three-dimensional echocardiographic recordings for enhanced field of view imaging

The use of three-dimensional (3-D) echocardiography is limited by signal dropouts and narrow field of view. Data compounding is proposed as a solution to overcome these limitations by combining multiple 3-D recordings to form a wide field of view. The first step of the solution requires registration between the recordings both in the spatial and temporal dimension for dynamic organs such as the heart. Accurate registration between the individual echo recordings is crucial for the quality of compounded volumes. A temporal registration method based on a piecewise one-dimensional cubic B-spline in combination with multiscale iterative Farnebäck optic flow method for spatial registration was described. The temporal registration method was validated on in vivo data sets with annotated timing of mitral valve opening. The spatial registration method was validated using in vivo data and compared to registration with Procrustes analysis using manual contouring as a benchmark. The spatial accuracy was assessed in terms of mean of absolute distance and Hausdorff distance between the left ventricular contours. The results showed that the temporal registration accuracy is in the range of half the time resolution of the echo recordings and the achieved spatial accuracy of the proposed method is comparable to manual registration.

Intraoperative three-dimensional transesophageal echocardiography for evaluating an unusual structure in the left ventricular outflow tract: a case report

Intraoperative three-dimensional (3D) transesophageal echocardiography (TEE) facilitates an understanding of the complex cardiac pathology that is not fully delineated in a two-dimensional (2D) echocardiographic evaluation, and it suggests earlier and more precise surgical planning and intraoperative decision making. In the present case, the intraoperative 2D-TEE midesophageal long-axis view indicated a significant narrowing of the left ventricular outflow tract (LVOT) area by a band-like structure that vertically traversed the middle of the LVOT and connected to the anterior mitral leaflet base and the interventricular septum. However, additional 3D-TEE images of the LVOT and their cropped and rendered 2D images showed that web-like tissue, which presumably had grown around the patch closure from a previous atrioventricular septal defect, was obstructing the LVOT partially.

[Application fields of intraoperative transesophageal 3D echocardiography]

Intraoperative transesophageal echocardiography (TEE) is an established diagnostic tool and has to be regarded as the standard of care for intraoperative monitoring and cardiac surgical decision-making. Furthermore, intraoperative TEE is also used for monitoring and assessment of hemodynamic changes and the detection of previously unknown pathologies. In the past few years 3D-TEE has extended the spectrum of 2D-TEE by allowing pathomorphological features to be more easily and intuitively linked to the anatomy of the heart and the great vessels. Thus, a comprehensive 2D-TEE examination is favorably complemented by focused 3D-TEE. Especially during mitral valve surgery, 3D-TEE has proven its superiority in the diagnosis of the underlying pathology as demonstrated by a large number of studies in this field. This review presents the available data about the role of intraoperative 3D-TEE echocardiography and introduces practical fields of application.

Three-Dimensional Echocardiography: Advancements in Qualitative and Quantitative Analyses of Mitral Valve Morphology in Mitral Valve Prolapse

Degenerative mitral valve disease (MVD) is the leading cause of organic mitral regurgitation (MR), one of the most common valvular heart disease in western countries. Substantial progresses in the surgical treatment of degenerative MVD have improved life expectancy of patients with significant MR. However, prognosis, surgical decision and timing of surgery strongly depend on the accurate characterization of mitral valve (MV) anatomy and pathology and on the precise quantification of MR. Three-dimensional (3D) echocardiography, a major technological breakthrough in the field of cardiovascular imaging, provides several advantages over two-dimensional (2D) imaging in the qualitative and quantitative evaluations of MV apparatus. In this review, we focus on the contribution of this new modality to the diagnosis of degenerative MVD, the quantitative assessment of MR severity, the selection and monitoring of surgical and percutaneous procedures, the evaluation of procedural outcomes. The results of a systematic and exhaustive search of the existing literature, restricted to real-time 3D echocardiography in adults, are here reported.

Three-dimensional echocardiography of the mitral valve: lessons learned

Three-dimensional echocardiography has markedly improved our understanding of normal and pathologic mitral valve (MV) mechanics. Qualitative and quantitative analysis of three-dimensional (3D) data on the mitral valve could have a clinical impact on diagnosis, patient referral, surgical strategies, annuloplasty ring design and evaluation of the immediate and long-term surgical outcome. This review covers the contribution of 3D echocardiography in the diagnosis of MV disease, its role in selecting and monitoring surgical procedures, and in the assessment of surgical outcomes. Moreover, advantages of this technique versus the standard 2D modality, as well as future applications of advanced analysis techniques, will be reviewed.

Cardiac axis-oriented full-volume data acquisition in real-time three-dimensional transesophageal echocardiography to facilitate on-cart analysis

We propose a useful method to acquire a full-volume dataset that allows for efficient assessment of cardiac structures by real-time 3-dimensional transesophageal echocardiography (3DTEE). In our method, bicommissural full-volume acquisition, the dataset is acquired with the X-Y-Z axes aligned along the lines connecting the mitral commissures, the mitral annular center to the left ventricular apex, and the mitral anterior-posterior ends, respectively. The image dataset obtained using this method not only allows for visualization of en face images of the cardiac structures, but box cropping of the dataset also provides useful sectional images that are the analogues of the standard 2DTEE views. Our method can potentially standardize 3D image orientation of the cardiac structures and facilitate intraoperative on-cart analysis in real-time 3DTEE.