Three-Dimensional Transesophageal Echocardiography Is a Major Advance for Intraoperative Clinical Management of Patients Undergoing Cardiac Surgery: A Core Review

Transesophageal Echocardiography in Tetralogy of Fallot

Transesophageal echocardiography (TEE) plays an important role in the anatomical, functional, and hemodynamic assessment of patients with congenital heart disease (CHD). This imaging approach has been applied to both children and adults with a wide range of cardiovascular malformations. Extensive clinical experience documents significant contributions, particularly in the perioperative setting. In fact, in the current medical era, many consider this technology to be an essential adjunct to surgical and anesthetic management in CHD. This review focuses on the applications of TEE in patients with tetralogy of Fallot (TOF), the most common form of cyanotic heart disease. Emphasis is given to the perioperative use of this imaging modality and benefits derived during the prebypass and postbypass periods. Limitations and pitfalls relevant to the TEE assessment in patients with this anomaly are also addressed.

Direct percutaneous left ventricular access and port closure: pre-clinical feasibility

OBJECTIVES

This study sought to evaluate feasibility of nonsurgical transthoracic catheter-based left ventricular (LV) access and closure.

BACKGROUND

Implanting large devices, such as mitral or aortic valve prostheses, into the heart requires surgical exposure and repair. Reliable percutaneous direct transthoracic LV access and closure would allow new nonsurgical therapeutic procedures.

METHODS

Percutaneous direct LV access was performed in 19 swine using real-time magnetic resonance imaging (MRI) and an "active" MRI needle antenna to deliver an 18-F introducer sheath. The LV access ports were closed percutaneously using a commercial ventricular septal defect occluder and an "active" MRI delivery cable for enhanced visibility. We used "permissive pericardial tamponade" (temporary fluid instillation to separate the 2 pericardial layers) to avoid pericardial entrapment by the epicardial disk. Techniques were developed in 8 animals, and 11 more were followed up to 3 months by MRI and histopathology.

RESULTS

Imaging guidance allowed 18-F sheath access and closure with appropriate positioning of the occluder inside the transmyocardial tunnel. Of the survival cohort, immediate hemostasis was achieved in 8 of 11 patients. Failure modes included pericardial entrapment by the epicardial occluder disk (n = 2) and a true-apex entry site that prevented hemostatic apposition of the endocardial disk (n = 1). Reactive pericardial effusion (192 ± 118 ml) accumulated 5 ± 1 days after the procedure, requiring 1-time drainage. At 3 months, LV function was preserved, and the device was endothelialized.

CONCLUSIONS

Direct percutaneous LV access and closure is feasible using real-time MRI. A commercial occluder achieved hemostasis without evident deleterious effects on the LV. Having established the concept, further clinical development of this approach appears realistic.

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.

Role of transesophageal echocardiography in the management of pediatric patients with congenital heart disease

Transesophageal echocardiography (TEE) has become a critical diagnostic and perioperative management tool for patients with congenital heart disease (CHD) undergoing cardiac and noncardiac surgical procedures. This review highlights the role of TEE in routine management of pediatric cardiac patient population with focus on indications, views, applications and technological advances.