Intraoperative transesophageal echocardiography (TEE) is one of the mainstays of modern cardiac anesthesiology. Conventional 2 dimensional TEE cannot display the full dynamic motion of the three dimensional heart. Two-dimensional echocardiography has been the standard for clinical monitoring during cardiac surgery. This is changing as three-dimensional echocardiography becomes more available.
Dr. Alessandra Meris, Division of Cardiothoracic Anesthesiology, Fondazione CardiocentroTicino, Lugano, Switzerland, and coauthors compared 2D and 3D measurements of left ventricular volumes in patients undergoing elective cardiac surgery. The results of their study were published in last month’s edition of Anesthesia & Analgesia in the article “Intraoperative Three-Dimensional Versus Two-Dimensional Echocardiography for Left Ventricular Assessment.”
The authors studied 152 patients. Both 2D and 3D images were acquired after anesthesia induction, before sternotomy. They found that left ventricular volumes assessed using 3D images were about 2 mm larger than when assessed with 2D images. The clinical relevance of this difference is small, and came at the expense of longer analysis times with 3D technology. There were no statistically significant differences between 2D and 3D TEE in left ventricular ejection fraction, image quality, and reproducibility.
Ideally, comparisons with such devices as MRI might provide more insight into possible benefits of 3D technology. Such comparisons are difficult in anesthetized patients about to undergo a surgical procedure. These results suggest that the benefits of current 3D TEE technology are not yet sufficiently compelling for us to replace our 2D TEE devices.