Real-time Three-Dimensional Transesophageal Echocardiography: The Matrix Revolution

[Consensus on Perioperative Transesophageal Echocardiography of the Brazilian Society of Anesthesiology and the Department of Cardiovascular Image of the Brazilian Society of Cardiology]

Through the Life Cycle of Intraoperative Transesophageal Echocardiography (ETTI/SBA) the Brazilian Society of Anesthesiology, together with the Department of Cardiovascular Image of the Brazilian Society of Cardiology (DIC/SBC), createded a task force to standardize the use of intraoperative transesophageal echocardiography by Brazilian anesthesiologists and echocardiographers based on scientific evidence from the Society of Cardiovascular Anesthesiologists/American Society of Echocardiography (SCA/ASE) and the Brazilian Society of Cardiology.

Consensus on Perioperative Transesophageal Echocardiography of the Brazilian Society of Anesthesiology and the Department of Cardiovascular Image of the Brazilian Society of Cardiology

Through the Life Cycle of Intraoperative Transesophageal Echocardiography (ETTI/SBA) the Brazilian Society of Anesthesiology, together with the Department of Cardiovascular Image of the Brazilian Society of Cardiology (DIC/SBC), created a task force to standardize the use of intraoperative transesophageal echocardiography by Brazilian anesthesiologists and echocardiographers based on scientific evidence from the Society of Cardiovascular Anesthesiologists/American Society of Echocardiography (SCA/ASE) and the Brazilian Society of Cardiology.

Role of 3D Echocardiography in Cardiac Surgery: Strengths and Limitations

PURPOSE OF REVIEW

This review aims to highlight the general and specific strengths and limitations of intraoperative 3D echocardiography. This article explains the value of real-time three-dimensional transesophageal echocardiography (RT 3D TEE) during cardiac surgery and cardiac interventions.

RECENT FINDINGS

Recently published recommendations and guidelines include the use of RT 3D TEE. RT 3 D TEE provides additional value particularly for guidance during cardiac interventions (i.e., transcatheter mitral valve repair, left atrial appendix and atrial septal defect closures), assessment of the mitral valve in surgical repair, measurement of left ventricular outflow tract area for transcatheter valvular replacements, and estimating right and left ventricular volumes and function. The exact localization of paravalvular leakage is another strength of RT 3D TEE. The major limitation is the reduced temporal resolution compared to 2D TEE.

SUMMARY

Three-dimensional echocardiography is a powerful tool that improves communication and accurate measurements of cardiac structures.

A Hybrid Method for Endocardial Contour Extraction of Right Ventricle in 4-Slices from 3D Echocardiography Dataset

This paper presents a hybrid method to extract endocardial contour of the right ventricular (RV) in 4-slices from 3D echocardiography dataset. The overall framework comprises four processing phases. In Phase I, the region of interest (ROI) is identified by estimating the cavity boundary. Speckle noise reduction and contrast enhancement were implemented in Phase II as preprocessing tasks. In Phase III, the RV cavity region was segmented by generating intensity threshold which was used for once for all frames. Finally, Phase IV is proposed to extract the RV endocardial contour in a complete cardiac cycle using a combination of shape-based contour detection and improved radial search algorithm. The proposed method was applied to 16 datasets of 3D echocardiography encompassing the RV in long-axis view. The accuracy of experimental results obtained by the proposed method was evaluated qualitatively and quantitatively. It has been done by comparing the segmentation results of RV cavity based on endocardial contour extraction with the ground truth. The comparative analysis results show that the proposed method performs efficiently in all datasets with overall performance of 95% and the root mean square distances (RMSD) measure in terms of mean ± SD was found to be 2.21 ± 0.35 mm for RV endocardial contours.

Real-time three-dimensional transesophageal echocardiography to predict artificial chordae length for mitral valve repair

Background

Artificial chordae replacement is an effective technique for mitral valve repair, however, it is difficult to accurately determine the length of artificial chordae. This study aimed to assess the reliability and accuracy of real-time three-dimensional transesophageal echocardiography (TEE) to predict the length of artificial chordae preoperatively.

Methods

From December 2008 to December 2010, 48 patients with severe mitral regurgitation successfully underwent mitral valve repair using artificial chordae replacement. The patients were divided into a TEE pre-measurement group (n = 26) and a direct measurement group (n = 22), according to the method used to determine the length of artificial chordae. Cardiopulmonary bypass time, aortic cross-clamp time, and the recurrence rate of moderate or severe mitral regurgitation were compared between the two groups.

Results

There were no operative deaths in either group. The mean cardiopulmonary bypass time was 113.0 ± 18.7 min and 127.0 ± 28.9 min (p < 0.05), and the aortic cross-clamp time was 70.0 ± 16.6 min and 86.0 ± 20.7 min (p < 0.05) in the TEE pre-measurement group and direct measurement group, respectively. The difference between the pre-measured artificial chordal length and actual constructed artificial chordal length was not significant in the TEE pre-measurement group (p > 0.05). Although the difference in the incidence of moderate or severe mitral regurgitation between the two groups was not significant (p > 0.05), the incidence in the TEE pre-measurement group (3.8%) was lower than that in the direct measurement group (18.2%).

Conclusions

Real-time three-dimensional transesophageal echocardiography can accurately predict the length of artificial chordae required for mitral valve repair, and shortens cardiopulmonary bypass time and aortic cross-clamp time while improving the results of mitral valve repair.