**3. Sizing of annulus and sinotubular junction**

In aortic valve replacement, the bioprosthetic valve has gained in popularity because of its long-term durability as well as its lack of dependence on anticoagulation. However, the annular size limits the use of bioprostheses in patients with small stature. Calcifications in the annulus also limit the size of the implanted valve.

In addition to preoperative transthoracic echocardiography, the annular size is measured with TEE following induction of anesthesia. In midesophageal aortic valve long-axis view, the aortic annulus is best visualized with the hinge points of the right coronary and

The aortic valve is most clearly visualized in midesophageal aortic valve long- and shortaxis view through the left atrium as an acoustic window (Fig. 1a,b). Aortic regurgitation is readily assessed in the former, and every cusp and the sinus of Valsalva are visualized in the latter. Because the direction of blood flow is nearly perpendicular to the ultrasound beam in both views, Doppler measurements as an assessment of the pressure gradient in aortic stenosis cases are done in transgastric long-axis view (Fig. 1c) with minimal incident

Due to the bulbar shape of the cusps and the sinus of Valsalva, visualization is limited in two-dimensional imaging of the aortic valve. 3D TEE is useful for visualizing all three cusps in a single view as well as surrounding structures such as the coronary artery and the sinus

Fig. 1. Basic imaging of aortic valve. a: midesophageal aortic valve (AV) long-axis view; b: midesophageal aortic valve short-axis view; c: transgastritic long-axis view, d: 3D TEE view from the aortic side. AAO: ascending aorta, LA: left atrium, LCC: left coronary cusp,

In aortic valve replacement, the bioprosthetic valve has gained in popularity because of its long-term durability as well as its lack of dependence on anticoagulation. However, the annular size limits the use of bioprostheses in patients with small stature. Calcifications in

In addition to preoperative transthoracic echocardiography, the annular size is measured with TEE following induction of anesthesia. In midesophageal aortic valve long-axis view, the aortic annulus is best visualized with the hinge points of the right coronary and

LV: left ventricle, NCC: noncoronary cusp, RCC: right coronary cusp

**3. Sizing of annulus and sinotubular junction** 

the annulus also limit the size of the implanted valve.

**2. Visualization of aortic valve** 

angle.

of Valsalva (Fig. 1d).

non-coronary cusps identified as the intersection of the cusp and the sinus of Valsalva. The internal dimension of these points can then be measured (Fig. 2). In those patients with a calcified annulus, the external margin of calcium is calipered in order to assess the largest implantable valve size that would accommodate a single interrupted or non-everting mattress suture after the calcium is meticulously removed. When intraannular placement with everting mattress sutures is considered, a prosthesis one size smaller is chosen.

The internal diameter at the sinotubular junction level is important. When it is equal to or smaller than the annular dimension as in Fig. 2b, it is difficult to insert the prosthetic valve down to the annular level and a very narrow space for ligation is anticipated.

Fig. 2. Assessment of aortic valve and ascending aorta. Left: check points. a: measurement of annular dimension and sinotubular junction; b: small sinotubular junction
