With the advent and availability of transcatheter TV therapies, computed tomography (CT) has become a mandatory in defining patients’ anatomy and eligibility.

Since it offers a comprehensive assessment of the real three-dimensional (3D) anatomy, CT allows the operator to assess the TV anatomy as well as the adjacent structures including the proximity of the right coronary artery to the tricuspid annulus, the coronary sinus, the hepatic veins and vena cava (Fig. 19.1a). For some devices it is crucial also the assessment of the shape and dimension of the RV, including the distant between the RV apex and the annular plane (this is the case for the valve spacer). Moreover, angio-CT allow the operator to have a qualitative assessment of the tissue quality, which is particular important for annulopasty devices which rely on anchor fixation, in order to identifhy the optimal target zone for the implant. Another features of CT scan is that it allows for each patient an easy and reliable prediction of the fluoroscopic working plane during the procedure, which are usually 2, one en-face view (normally LAO) and one view parallel to the annulus (normally RAO).

Transesophageal 2D and 3D echocardiography (TEE) is also the essential imaging technique in the assessment of patients with TR (Fig. 19.1b), in order to assess the mechanism and location of regurgitation, to quantify the annular dimensions and to assess the RV function and valve tethering.

Although preliminary experience showed the feasibility of TV interventions, intraprocedural guidance remain a major issue, since in many patients the echocardiographic window for the TV may be suboptimal and the procedural steps have not yet been standardized. Both two-dimensional (2D) and 3D TEE as well as intracardiac echocardiography (ICE) also play an essential role during transcatheter TV interventions. In some patients, transthoracic echocardiography (TTE) may help to define TV morphology and right ventricular anatomy to identify the target zone of the device implantation. This is particular helpful in MitraClip procedures , in which a proper assessment of the leaflets insertion is mandatory to achieve procedural success [8]. Procedural guidance with 3D-TEE represents a fundamental tool to orient the navigation in the right atrium. However, in many patients the quality of intra-procedural guidance can often be suboptimal, mainly depending on patient variability and individual echo window. Moreover, the three-leaflet configuration of the TV precludes the visualization of all the leaflets in the same view in conventional 2D echo. This aspect contributes to increase technical complexity of TV interventions. A detailed intra-procedural imaging is of particular importance not only to guide the operator to the segment of the valve which represent the target leaflet or commisure, but is crucial to define the orientation of the anatomy and to assess leaflet insertion. The use of the EchoNavigator^®-system (Philips Healthcare, Best, the Netherlands) may help to overcome the intrinsic limits of imaging guidance in TV interventions, since multimodality fusion imaging may define the target zone increases tremendously the chance of procedural success [7]. Additionally, it is of crucial importance to define a common nomenclature in order to standardize procedural 3D TEE guidance. It should be shared between the one who is performing the procedure and the one who is guiding. With this in mind, a communication between the heart team (e.g. echo-cardiologist, interventionalist and surgeon) is fundamental; therefore, all the operators involved in the procedure should speak “the same language”. This is even more important at this stage, and this can avoid some misunderstand “the eyesight” in each staff. We recently propose a “Rosetta Stone” nomenclature for 3D TEE navigation during transcatheter TV interventions as practical considerations for the heart team [13]. The identification of the location of the aortic valve (AV) is fundamental to understand the orientation of the leaflets: the leaflet opposite to the AV is the posterior leaflet. Anterior and septal leaflets are easily identified counterclockwise (Fig. 19.2).

In patients with previous tricuspid surgery, transcatheter valve-in-valve or valve-in-ring procedures can be performed using a transfemoral or transjugular approach even in patients with pre-existing transvalvular pacemaker leads [9–11]. Different prostheses have been used to perform tricuspid valve in valve and valve in ring (mainly Sapien XT, Sapien 3 and Melody).

The transfemoral approach may be technically challenging in most cases, due to an unfavorable narrow angle between the inferior vena cava (IVC) and the TV, which may preclude positioning of the prosthesis valve, especially in case of Sapien XT and Sapien 3 valve, which have a pretty stiff delivery system. By snaring the Commander catheter , flexion of the system can be increased by simple pulling on the snare, thereby adapting the angle of the catheter to the patient’s anatomy (Fig. 19.3) [9].

Regarding valve in ring, in the tricuspid position surgical rings usually are incomplete ring and have a non-circular and non-planar shape. As a result, compared to mitral position, tricuspid valve-in-ring presents some specific difficulties. On the other hand, unlike the mitral position, the risk of right ventricle (RV) outflow obstruction is absent, and residual paravalvular leak and risk of embolization are less of an issue as a result of the low-pressure RV system. As a support for prosthesis sizing, during the procedure, balloon sizing may be useful to determine the annulus dimension more precisely [12]. Although the ring has the advantage of providing the landmarks and necessary anchoring for a percutaneous valve, it also has the drawback of creating a non-circular landing zone with the inability to seal completely the open segment with the implanted valve. Therapeutic advances with more conformable or repositionable valves with additional sealing capacity are required to reduce regurgitation after transcatheter valve-in-ring implantation.

In patients with native TV disease, many percutaneous techniques mimic surgical techniques is innovated. Novel transcatheter devices have begun to emerge for the treatment of TR, and these transcatheter devices are currently under preliminary clinical evaluation to treat functional TR. Risks and limitations of each devices have to be taken in consideration in the patient selection process (Fig. 19.4).

Another practical consideration that has to be done refers to how to report the outcomes of these new tricuspid therapies, since no standardized definitions are present. First of all, it would be recommendable to report precise quantitative measurements of TR reduction (like EROA and Regurgitant Volume). Secondarily, it is not really clear which will be the best outcome to evaluate in these patients, since most likely improvement in quality of life would be more appropriate than improvement in survival. Anyway, similarly to what has been done for aortic and mitral valves, there is an urgent need for a consensus regarding standardized end-point and reporting outcomes in transcatheter tricuspid interventions.