3D transesophageal echocardiography in TAVR

Abstract

Recently, there has been an increasingly minimalistic approach to transcatheter aortic valve replacement (TAVR), with most procedures now performed under conscious sedation without real time transesophageal echocardiography (TEE) guidance. Proponents of echo should not feel discouraged by this; it is the initial insights that were gained with procedural TEE during the early years of TAVR that have allowed the procedure's gradual maturation and sophistication. Experienced centers that have promoted extensive TAVR TEE programs continue to maximize the benefits of echocardiography in both procedural planning and execution. Critical to this is the understanding of 3D TEE, allowing the annulus to be sized accurately, relevant neighboring anatomy defined, and complications flagged. This review will outline the current application of 3D TEE in TAVR and discuss challenges and opportunities for 3D echocardiography in this field. 2 | PREPROCEDURE 2.1 | 3D in TAVR planning-zoom, full volume, or live? 3D imaging can be thought of as a virtual representation of how a structure would look geometrically if held in your hand, but not necessarily how it would look aesthetically. In echo, this is achieved with a matrix array probe to acquire volumes of ultrasound data composed of voxels; the larger the voxel, the poorer the resolution. A matrix array probe has several thousand piezoelectric elements and can steer a scan line in lateral, elevation, and azimuth planes generating a 3D image. Line density impacts the spatial resolution and, together with gain and compression settings, should be optimized in 2D prior to attempting 3D acquisition. There are 3 possible modes of 3D acquisition; live, zoom, and full volume. Live 3D is often seen as limited in structural echocardiography as

The role of far-field intravascular ultrasound in transcatheter aortic valve replacement

“…MDCT is the gold stand for pre TAVR assessment of the aortic valve complex and assessing the iliofemoral vasculature for access consideration [ 3 ]. As compared to Two dimensional (2D) TEE, MDCT provides a more accurate assessment of the aortic annulus measurements and does not require sedation [ 4 , 8 ]. The reliance on intraprocedural 2D TEE in TAVR has steadily declined over the past 5 years as conscious sedation became the standard approach.…”

Bend‐insensitive fiber optic ultrasonic tracking probe for cardiovascular interventions

“…The US tracking system comprised an US imaging system (Ultrasonix MDP, BK Medical, UK) with two probes: a phased array TEE probe (mTEE8‐3/5; center frequency at 6 MHz; 16 elements) and a side‐viewing linear array laparoscopic probe (LAP9‐4/38; frequency range 4–9 MHz; 128 elements). The laparoscopic probe was used as a surrogate to a clinical‐grade TEE probe 25 , 26 to obtain high‐quality cardiac US images. With eight times more transducer elements and a US lens for elevational focus, this laparoscopic probe produced far higher quality US images than the research‐grade TEE probe used in this study.…”

Three-Dimensional Transesophageal Echocardiography in Percutaneous Catheter-Based Cardiac Interventions

“…In complex cases, 3D-TEE may improve the visualization of the stent [15]. The use of fusion techniques to overlay 3D-TEE and fluoroscopy can outline the annulus with higher precision [12,16]. It is critical to consider that proper positioning and deployment will depend on the type of device used (balloon-expandable, self-expanding, and mechanically expanded), and each case should be tailored according to the valve size, the characteristics and dimensions of the aortic root, and the location of the left main coronary artery [15,17].…”