The American Heart Association/American College of Cardiology 2014 guidelines on valvular heart disease recommend tricuspid valve surgery in the following situations [3]:

The classes of recommendation are as follows:

The levels of evidence are as follows:

The recommendation to intervene on the tricuspid valve when the tricuspid annulus is dilated in the absence of significant tricuspid regurgitation (TR) was first made by Dreyfus, et al., in 2005 [11]. In an observational study on 311 patients undergoing mitral valve repair in whom tricuspid annuloplasty was also performed if the tricuspid annulus was dilated to more than 70 mm measured intra-operatively (from the antero-septal commissure to the antero-posterior commissure), it was observed that NYHA functional class was significantly better at 5 years in those in whom a concomitant tricuspid annuloplasty was performed. In addition, TR progressed in those who did not have a concomitant tricuspid annuloplasty but not in those who did [11]. The observation that mild or moderate FTR progresses in 15–40 % of patients if left untreated has been reported in numerous other studies including a meta-analysis [7, 10, 12–25]. Goldstone, et al., reported that the proportion of patients with moderate or more TR increased from 7.9 % at baseline to 36 % 9 years after isolated mitral valve surgery, and this was associated with right ventricular dysfunction [10]. Of note, the mean tricuspid annular diameter is this study was 40.1 mm, which is the current threshold size at which concomitant tricuspid valve repair is recommended. The study also reported that FTR progressed in those with only mild TR if the baseline indexed tricuspid annular diameter was greater than 21 mm/m² [10]. Tricuspid annular dilation, TR severity, right ventricular dysfunction, pulmonary hypertension, atrial fibrillation, enlarged left and right atria and rheumatic etiology are amongst the common risk factors for TR progression which have been identified [7, 10, 22, 23, 26, 27]. In a randomized trial of patients with mild tricuspid regurgitation and tricuspid annular dilatation undergoing mitral valve surgery, patients randomized to receive a tricuspid annuloplasty had less TR progression, improved right ventricular reverse remodeling, and better functional outcomes compared to patients who did not receive a tricuspid annuloplasty [15]. Similar observations have been made in a few other studies [18, 28]. Importantly, several studies have reported an association with reduced survival in those with significant late TR or those in whom there is progression of TR [13, 14, 16, 21, 27, 29]. Re-operations on the tricuspid valve in those who subsequently develop symptomatic severe TR also carries a high hospital mortality of between 14 and 35 % [30–32].

Correction of significant TR has been shown to improve right ventricular geometry and function, and pulmonary artery pressures [28, 33, 34]. Studies have also shown an improvement in functional capacity and survival following tricuspid annuloplasty [11, 13]. Prophylactic tricuspid annuloplasty performed when the tricuspid annulus is dilated but before the onset of severe TR also prevents the progression of TR and right ventricular dilatation, improves the functional capacity and survival of the patient, and avoids the need for future re-operative tricuspid valve surgery which carries a high operative risk [11, 13, 18].

Tricuspid annuloplasty can be performed using either a tricuspid annuloplasty ring or band, or by various suture annuloplasty techniques. Several studies have reported a lower recurrence rate of TR when an annuloplasty ring is used as compared to suture annuloplasty, and some have reported improved survival when an annuloplasty ring is used for tricuspid valve repair [35, 36]. Tricuspid ring annuloplasty will be described in this chapter. Tricuspid suture annuloplasty is covered in a separate chapter.

The tricuspid annulus can be sized by measuring its leaflet area by pulling on the anterior papillary muscle which supports both the anterior and posterior leaflets and using an obturator to determine this size (Fig. 21.2a). It can also be sized by measuring the orifice area by matching the corresponding notches of the obturator to the antero-septal and postero-septal commissures i.e., the length of the septal annulus (Fig. 21.2b). If there is a discrepancy in size between the two measurements, then the size obtained by using the orifice area i.e., the septal annulus length, should be used as this is relatively fixed in size and does not dilate. A discrepancy in size with the leaflet area being smaller than the orifice area is also an indication for tricuspid valve repair as this suggests that the leaflets are of insufficient size to achieve valvular competence [9].

In the presence of severe FTR, the annuloplasty ring can be undersized to increase leaflet coaptation [37]. For example, if the annulus is sized at 34 mm, a 32 mm ring could be used instead. However, caution must be exercised particularly in elderly patients with weak tissue as the excess tension can cause annular dehiscence particularly at the septal annulus [38]. A series of 2/0 ethibond sutures or equivalent are placed around the tricuspid annulus except at the region of the conduction tissues at the septal annulus (Fig. 21.3). The sutures are then in turn passed through the tricuspid annuloplasty ring. Care is needed around the posterior annulus to avoid the right coronary artery, and in the region of the anterior annulus where too deep a suture may cause injury to the aortic wall and aortic valve leaflets. As a precaution, traction can be exerted on the sutures placed in the posterior leaflet annulus after placement to ensure that there is no visible distortion of the right coronary artery. If any suggestion of distortion or occlusion of the right coronary artery is suggested by this maneuver, the sutures should be removed and placed again carefully.

Several commercially available tricuspid annuloplasty rings are available with the newer rings shaped geometrically into a 3-dimensional configuration to match the normal geometry of the tricuspid annulus. Care must be taken during suture placement to ensure that the sutures are passed through the annuloplasty ring at their corresponding positions on the tricuspid annulus so as not to distort the tricuspid valve. Two important landmarks are the anteroposterior commissure and the posteroseptal commissures which should pass through the corresponding positions in the tricuspid annuloplasty ring. The annuloplasty ring is then lowered and the sutures tied. A water test is performed while occluding the pulmonary artery to confirm valve competency. To minimize myocardial ischaemia times, the tricuspid valve annuloplasty can be done after the release of the aortic cross clamp and during the period of rewarming and reperfusion.