Live 3-Dimensional Transesophageal Echocardiography Initial Experience Using the Fully-Sampled Matrix Array Probe

ObjectivesOur study goals were to evaluate the 3-dimensional matrix array transesophageal echocardiographic (3D-MTEE) probe by assessing the image quality of native valves and other intracardiac structures.BackgroundBecause 3-dimensional transesophageal echocardiography with gated rotational acquisition is not used routinely as the result of artifacts, lengthy acquisition, and processing, a 3D-MTEE probe was developed (Philips Medical Systems, Andover, Massachusetts).MethodsIn 211 patients, 3D-MTEE zoom images of the mitral valve (MV), aortic valve, tricuspid valve, interatrial septum, and left atrial appendage were obtained, followed by a left ventricular wide-angled acquisition. Images were reviewed and graded off-line (Xcelera with QLAB software, Philips Medical Systems).ResultsExcellent visualization of the MV (85% to 91% for all scallops of both MV leaflets), interatrial septum (84%), left atrial appendage (86%), and left ventricle (77%) was observed. Native aortic and tricuspid valves were optimally visualized only in 18% and 11% of patients, respectively.ConclusionsThe use of 3D-MTEE imaging, which is feasible in most patients, provides superb imaging of native MVs, which makes this modality an excellent choice for MV surgical planning and guidance of percutaneous interventions. Optimal aortic and tricuspid valve imaging will depend on further technological developments. Fast acquisition and immediate online display will facilitate wider acceptance and routine use in clinical practice

Beating-heart patch closure of muscular ventricular septal defects under real-time three-dimensional echocardiographic guidance: A preclinical study

ObjectivesSafe and effective device closure of ventricular septal defects remains a challenge. We have developed a transcardiac approach to close ventricular septal defects using a patch delivery and fixation system that can be secured under real-time three-dimensional echocardiographic guidance.MethodsIn Yorkshire pigs (n = 8) a coring device was introduced into the left ventricle through a purse-string suture placed on the left ventricular apex, and a muscular ventricular septal defect was created. The patch deployment device containing a 20-mm polyester patch was advanced toward the ventricular septal defect through another purse-string suture on the left ventricular apex, and the patch was deployed under real-time three-dimensional echocardiographic guidance. The anchor delivery device was then introduced into the left ventricle through the first purse-string suture. Nitinol anchors to attach the patch around the ventricular septal defect were deployed under real-time three-dimensional echocardiographic guidance. After patch attachment, residual shunts were sought by means of two-dimensional and three-dimensional color Doppler echocardiography. The heart was then excised, and the septum with the patch was inspected.ResultsA ventricular septal defect was created in the midventricular (n = 4), anterior (n = 2), and apical (n = 2) septum. The mean size was 9.8 mm (8.2–12.0 mm), as determined by means of two-dimensional color Doppler scanning. The ventricular septal defects were completely closed in 7 animals. In one a 2.4-mm residual shunt was identified. No anatomic structures were compromised.ConclusionsBeating-heart perventricular muscular ventricular septal defect closure without cardiopulmonary bypass can be successfully achieved by using a catheter-based patch delivery and fixation system under real-time three-dimensional echocardiographic guidance. This approach might be a better alternative to cardiac surgery or transcatheter device closure

Stereoscopic vision display technology in real-time three-dimensional echocardiography-guided intracardiac beating-heart surgery

ObjectiveStereoscopic vision display technology has been shown to be a useful tool in image-guided surgical interventions. However, the concept has not been applied to 3-dimensional echocardiography-guided cardiac procedures. We evaluated stereoscopic vision display as an aid for intracardiac navigation during 3-dimensional echocardiography-guided beating-heart surgery in a model of atrial septal defect closure.MethodsAn atrial septal defect (6 mm) was created in 6 pigs using 3-dimensional echocardiography guidance. The defect was then closed using a catheter-based patch delivery system, and the patch was attached with tissue mini-anchors. Stereoscopic vision was generated with a high-performance volume renderer with stereoscopic glasses. Three-dimensional echocardiography with stereoscopic vision display was compared with 3-dimensional echocardiography with standard display for guidance of surgical repair. Task performance measures for each anchor placement (N = 32 per group) were completion time, trajectory of the tip of the anchor deployment device, and accuracy of the anchor placement.ResultsThe mean time of the anchor deployment for stereoscopic vision display group was shorter by 44% compared with the standard display group: 9.7 ± 0.9 seconds versus 17.2 ± 0.9 seconds (P < .001). Trajectory tracking of the anchor deployment device tip demonstrated greater navigational accuracy measured by trajectory deviation: 3.8 ± 0.7 mm versus 6.1 ± 0.3 mm, 38% improvement (P < .01). Accuracy of anchor placement was not significantly different: 2.3 ± 0.3 mm for the stereoscopic vision display group versus 2.3 ± 0.3 mm for the standard display group.ConclusionStereoscopic vision display combined with 3-dimensional echocardiography improved the visualization of 3-dimensional echocardiography ultrasound images, decreased the time required for surgical task completion, and increased the precision of instrument navigation, potentially improving the safety of beating-heart intracardiac surgical interventions

Border zone geometry increases wall stress after myocardial infarction: contrast echocardiographic assessment.

After myocardial infarction (MI), the border zone expands chronically, causing ventricular dilatation and congestive heart failure (CHF). In an ovine model (n = 4) of anteroapical MI that results in CHF, contrast echocardiography was used to image short-axis left ventricular (LV) cross sections and identify border zone myocardium before and after coronary artery ligation. In the border zone at end systole, the LV endocardial curvature (K) decreased from 0.86 +/- 0.33 cm(-1) at baseline to 0.35 +/- 0.19 cm(-1) at 1 h (P \u3c 0.05), corresponding to a mean decrease of 55%. Also in the border zone, the wall thickness (h) decreased from 1.14 +/- 0.26 cm at baseline to 1.01 +/- 0.25 cm at 1 h (P \u3c 0.05), corresponding to a mean decrease of 11%. By Laplace\u27s law, wall stress is inversely proportional to the product K. h. Therefore, a 55% decrease in K results in a 122% increase in circumferential stress; a 11% decrease in h results in a 12% increase in circumferential stress. These findings indicate that after MI, geometric changes cause increased dynamic wall stress, which likely contributes to border zone expansion and remodeling