Dynamic Annular Modeling of the Unrepaired Complete Atrioventricular Canal Annulus.

BACKGROUND: Repair of complete atrioventricular canal (CAVC) is often complicated by atrioventricular valve regurgitation, particularly of the left-sided valve. Understanding the 3-dimensional (3D) structure of the atrioventricular canal annulus before repair may help to inform optimized repair. However, the 3D shape and movement of the CAVC annulus has been neither quantified nor rigorously compared with a normal mitral valve annulus. METHODS: The complete annuli of 43 patients with CAVC were modeled in 4 cardiac phases using transthoracic 3D echocardiograms and custom code. The annular structure was compared with the annuli of 20 normal pediatric mitral valves using 3D metrics and statistical shape analysis (Procrustes analysis). RESULTS: The unrepaired CAVC annulus varied in shape significantly throughout the cardiac cycle. Procrustes analysis visually demonstrated that the average normalized CAVC annular shape is more planar than the normal mitral annulus. Quantitatively, the annular height-to-valve width ratio of the native left CAVC atrioventricular valve was significantly lower than that of a normal mitral valve in all systolic phases (P < .001). CONCLUSIONS: The left half of the CAVC annulus is more planar than that of a normal mitral valve with an annular height-to-valve width ratio similar to dysfunctional mitral valves. Given the known importance of annular shape to mitral valve function, further exploration of the association of 3D structure to valve function in CAVC is warranted.

A Virtual Reality System for Improved Image-Based Planning of Complex Cardiac Procedures.

The intricate nature of congenital heart disease requires understanding of the complex, patient-specific three-dimensional dynamic anatomy of the heart, from imaging data such as three-dimensional echocardiography for successful outcomes from surgical and interventional procedures. Conventional clinical systems use flat screens, and therefore, display remains two-dimensional, which undermines the full understanding of the three-dimensional dynamic data. Additionally, the control of three-dimensional visualisation with two-dimensional tools is often difficult, so used only by imaging specialists. In this paper, we describe a virtual reality system for immersive surgery planning using dynamic three-dimensional echocardiography, which enables fast prototyping for visualisation such as volume rendering, multiplanar reformatting, flow visualisation and advanced interaction such as three-dimensional cropping, windowing, measurement, haptic feedback, automatic image orientation and multiuser interactions. The available features were evaluated by imaging and nonimaging clinicians, showing that the virtual reality system can help improve the understanding and communication of three-dimensional echocardiography imaging and potentially benefit congenital heart disease treatment.

Virtual reality three-dimensional echocardiographic imaging for planning surgical atrioventricular valve repair.

OBJECTIVES: To investigate how virtual reality (VR) imaging impacts decision-making in atrioventricular valve surgery. METHODS: This was a single-center retrospective study involving 15 children and adolescents, median age 6 years (range, 0.33-16) requiring surgical repair of the atrioventricular valves between the years 2016 and 2019. The patients' preoperative 3-dimesnional (3D) echocardiographic data were used to create 3D visualization in a VR application. Five pediatric cardiothoracic surgeons completed a questionnaire formulated to compare their surgical decisions regarding the cases after reviewing conventionally presented 2-dimesnional and 3D echocardiographic images and again after visualization of 3D echocardiograms using the VR platform. Finally, intraoperative findings were shared with surgeons to confirm assessment of the pathology. RESULTS: In 67% of cases presented with VR, surgeons reported having "more" or "much more" confidence in their understanding of each patient's pathology and their surgical approach. In all but one case, surgeons were at least as confident after reviewing the VR compared with standard imaging. The case where surgeons reported to be least confident on VR had the worst technical quality of data used. After viewing patient cases on VR, surgeons reported that they would have made minor modifications to surgical approach in 53% and major modifications in 7% of cases. CONCLUSIONS: The main impact of viewing imaging on VR is the improved clarity of the anatomical structures. Surgeons reported that this would have impacted the surgical approach in the majority of cases. Poor-quality 3D echocardiographic data were associated with a negative impact of VR visualization; thus. quality assessment of imaging is necessary before projecting in a VR format.

Melody Valve Fracture Causing Mitral Stenosis: Novel Solution for Transapical Valve-in-Valve.

The use of Melody valves in the mitral position has been introduced in clinical practice. Stent fracture is a recognized complication of Melody valve implantation in the pulmonary position; however, reports in the mitral position are rare. We present the case of an 8-year-old boy in whom complete fracture of the proximal stent struts occurred, causing acute severe mitral stenosis, and in whom urgent hybrid transapical Melody valve implantation in the fractured Melody valve was performed successfully using a novel modified technique. This modification simplified the implantation, led to reduced time of the procedure, and minimized hemodynamic instability.

Transcatheter Correction of Superior Sinus Venosus Atrial Septal Defects as an Alternative to Surgical Treatment.

BACKGROUND: The superior sinus venosus atrial septal defect (SVASD) is characterized by deficiency of the common wall between the superior vena cava (SVC) and the right upper pulmonary vein (RUPV), which is no longer committed to the left atrium. OBJECTIVES: This study sought to evaluate the potential for redirecting the SVC and RUPV flow to the right and left atria, respectively, by implantation of a covered stent in the SVC. METHODS: Review of 48 consecutive adult SVASD patients undergoing assessment for correction. Pre-procedural evaluation included cross-sectional imaging and ex vivo simulation using printed or virtual 3-dimensional models. RESULTS: Transcatheter correction was performed in 25 patients, with a further 6 awaiting stent implantation. Only 8 patients were deemed technically unsuitable. The procedure involved balloon test inflation in the anticipated stent landing zone with simultaneous transesophageal echocardiography and pulmonary venography to confirm defect closure and unobstructed pulmonary venous drainage, followed by deployment of a 10-zig covered Cheatham platinum stent. Stents of lengths between 5 and 8 cm were implanted. A second, uncovered stent was used for anchoring in 9 patients. The RUPV was protected with a high-pressure balloon during stent implantation to prevent pulmonary venous obstruction in 4 patients. The median follow-up period was 1.4 (interquartile range: 0.8 to 1.7) years, with no mortality. Stent embolization occurred in 1 patient; another required drainage of hemopericardium. Cardiac computed tomography after 3 months confirmed unobstructed pulmonary venous return. At latest follow-up, a residual shunt was present in 1 patient. CONCLUSIONS: Transcatheter correction of SVASD may be considered as an alternative to surgery in a substantial proportion of patients.

A training programme in screening echocardiography.

BACKGROUND: Although the value of echocardiography in acutely unwell patients is well established, it is often difficult to deliver conventional studies immediately. This has led to the development of training programmes in screening echocardiography. CONTEXT: Echocardiography is a difficult skill to master and requires an integration of knowledge-based learning and mentored practical training. INNOVATION: We developed a three-stage programme: (1) a 1-day course containing didactic lectures on normal and abnormal pathology, a 2-hour practical element with rotation through different tutors then seminars and self-assessment, with an interactive quiz; (2) a period of consolidation via apprenticeship with a recognised trainer; and (3) formal assessment. IMPLICATIONS: We propose a specific training programme to teach the difficult practical skill of screening echocardiography. The use of theoretical and practical elements with structured teaching and an apprenticeship may serve as a model for teaching other practical skills in clinical medicine.

Intracardiac malignant Triton tumor: a first presentation.

We present the first case of an intracardiac malignant peripheral nerve sheath tumor with rhabdomyoblastic differentiation (malignant Triton tumor) in a 63-year-old man who underwent elective, uncomplicated resection of his symptomatic left atrial mass.

Expression of the Brn-3b transcription factor correlates with expression of HSP-27 in breast cancer biopsies and is required for maximal activation of the HSP-27 promoter.

In breast cancer, overexpression of the small heat shock protein, HSP-27, is associated with increased anchorage-independent growth, increased invasiveness, and resistance to chemotherapeutic drugs and is associated with poor prognosis and reduced disease-free survival. Therefore, factors that increase the expression of HSP-27 in breast cancer are likely to affect the prognosis and outcome of treatment. In this study, we show a strong correlation between elevated levels of the Brn-3b POU transcription factor and high levels of HSP-27 protein in manipulated MCF-7 breast cancer cells as well as in human breast biopsies. Conversely, HSP-27 is decreased on loss of Brn-3b. In cotransfection assays, Brn-3b can strongly transactivate the HSP-27 promoter, supporting a role for direct regulation of HSP-27 expression. Brn-3b also cooperates with the estrogen receptor (ER) to facilitate maximal stimulation of the HSP-27 promoter, with significantly enhanced activity of this promoter observed on coexpression of Brn-3b and ER compared with either alone. RNA interference and site-directed mutagenesis support the requirement for the Brn-3b binding site on the HSP-27 promoter, which facilitates maximal transactivation either alone or on interaction with the ER. Chromatin immunoprecipitation provides evidence for association of Brn-3b with the HSP-27 promoter in the intact cell. Thus, Brn-3b can, directly and indirectly (via interaction with the ER), activate HSP-27 expression, and this may represent one mechanism by which Brn-3b mediates its effects in breast cancer cells.