**1. Introduction**

In the modern era, the morbidity and mortality of aortic valve surgeries has been markedly reduced. These improvement have been seen in: 1) aortic valve replacement or repair; 2) aortic root replacement or valve-sparing operations; 3) surgery on aortic dissections complicated by aortic regurgitation; and 4) recently introduced transcatheter aortic valve implantations. However, the goal of consistent success without complication is hampered by a number of pitfalls listed in Table 1.

While some of these complications are preventable if essential and timely information is obtained, others are rare and unpredictable. For the latter, early diagnosis and the institution of appropriate measures without delay is important in minimizing serious sequelae. For this purpose, intraoperative imaging plays an important role in recognizing the events behind the scenes. This author has exclusively applied transesophageal echocardiography (TEE) and direct echo to aortic valve surgery. The aim of this chapter is to describe the details of echo imaging in aortic valve surgery with a number of tips and case presentations.


Table 1. Pitfalls and complications in aortic valve surgery

chosen.

Intraoperative Imaging in Aortic Valve Surgery as a Safety Net 5

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

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

Fig. 2. Assessment of aortic valve and ascending aorta. Left: check points. a: measurement of

The ascending aorta is exposed to various surgical procedures such as arterial cannulation, cross clamping, root cannula insertion and aortotomy, which is potentially responsible for intraoperative stroke and dissection. While the aorta is assessed for calcification or atheromatous changes in preoperative CT in most cases, TEE or direct echo facilitates a

TEE assessment is beneficial in minimizing interruptions in the surgical procedure. The aorta is visualized with TEE in midesophageal ascending aorta long- or short-axis view. Although the distal portion of ascending aorta used for cannulation has been deemed to be a blind zone, this can be minimized by two tips. One is the *look-up method* (Fig. 3a,b). Instead of withdrawing the probe to visualize the distal portion, the probe is rather advanced and anteflexion is applied. Improved visualization is obtained through the left atrium and right pulmonary artery as an acoustic window. Another is the *xPlane mode* (Fig. 3c,d). In the

annular dimension and sinotubular junction; b: small sinotubular junction

surgeon's ability to exactly locate these pathologies intraoperatively.

down to the annular level and a very narrow space for ligation is anticipated.

A: annular diameter B: diameter of sinotubular

C: distance between annulus and coronary orifice D: pathologies of aortic wall E: maximal diameter of ascending aorta

junction

**4. Assessment of aorta** 
