**5. Current surgical approaches to tricuspid regurgitation**

In the past decades, intervention was believed to be unnecessary, as repairing secondary TR would resolve the problems in the left ventricle, which was thought to help TR regress as well. The first experience regarding the prognosis of FTR was reported by Braunwald in 1967. Braunwald claimed that untreated FTR naturally resolves after treating mitral valve disease [30]. Later, Carpentier recommended surgical intervention for FTR in patients with mitral valve disease [31]. However, today's understanding suggests aggressive intervention to resolve this disease. Repairing left-sided valve disease has resulted in increased survival rates, making the long-term sequelae of TR more pronounced. During left heart surgery, severe secondary TR should also be corrected. In cases of moderate or even lower right ventricular dysfunction or enlarged tricuspid valve annulus TR should be addressed as well [32]. The indications for tricuspid valve procedure during left heart valve surgery are relatively simple, though there is limited data on how to approach a patient with functional TR with no indications for left heart surgery. The preferred approach for these patients has not been well defined [33]. The main surgical technique to repair functional TR with a dilated ring and normal leaflet and chordal structures is by rigid or flexible annular open or closed rings, which are also used in mitral valve surgery, aiming to reduce annulus size and provide leaflet coaptation [11].

Contrary to findings regarding isolated TV surgery, the increased risk of mortality associated with concomitant tricuspid annuloplasty during mitral valve surgery seems almost negligible in current practice. TV repair takes an additional 15 to 20 minutes, but it can be performed without prolonging the CPB time by removing the cross-clamp in the working and perfused heart. The incidence of heart block requiring pacemaker implantation is potentially greater with concurrent tricuspid surgery, although this has been refused by most comparative series, seeming largely dependent on the preferred annuloplasty technique. Similarly, the current literature has yet to confirm the theoretical incremental risk of postoperative bleeding with the addition of a right atriotomy suture line [34].

The anatomical characteristics of the TV determine the repair technique:


### **5.1 Annuloplasty**

Despite the multiple repair strategies for TV, the ring annuloplasty technique is the preferred treatment for preventing the long-term recurrence of TR associated with suture annuloplasty [35, 36]. Tricuspid annuloplasty devices, whether rigid or incomplete semirigid rings for creating annular remodeling, or flexible bands that provide annular reduction, are often focused on restructuring annular movement. To date, there has been no clear evidence of superiority for any annuloplasty device for preventing the recurrence of TR [37]. In functional or secondary TR, the non-planar native tricuspid annulus is larger, flatter, and more circular. Hence, the ideal annuloplasty device should consider the geometric changes and restore the normal threedimensional elliptical shape of the tricuspid annulus to reduce leaflet stress and tethering It should also focus on remodeling along the right ventricular free wall, but have an open design to protect the transmission system. Ideally, such a device would be "resilient" in areas of three-dimensional motion or areas prone to ring separation, particularly along the membranous septum [38].

### *5.1.1 Kay annuloplasty*

The first type of annuloplasty is suture annuloplasty, which can be done in one of two ways [39]. First Kay annuloplasty was introduced in 1962: involves creating a functional bicuspid valve by placing a suture through the posterior leaflet's commissure [40]. This surgical technique places a pledget-supported bed suture from the anterior-posterior commissure through the posterior annulus to the posteroseptal commissure. Deloche et al. have demonstrated posterior annular dilatation in functional TR, suggesting that this method would work in selected cases [41]. In 1965 Herald Kay reported his Kay bicuspidization procedure, where the posterior leaflet is plicated along the annulus, has shown good mid-term and long-term results [40]. Ghanta et al. have modified this technique (**Figure 3**) [42].

### *5.1.2 DeVega annuloplasty*

DeVega annuloplasty was introduced in 1972 as an alternative [43]. The classical De Vega annuloplasty consists of a pair of continuous sutures, running along the anterior and posterior annulus, often corresponding to the free walls of the right ventricle. The septal part of the annulus is typically not involved in the expansion and is reserved to protect the transmission system. In the classical De Vega technique, a 2/0 or 3/0 polypropylene suture starts from the posterior end of the septal part of the annulus and continues counterclockwise in the posterior and anterior parts. The suture needle is inserted 1 to 2 mm deep, into 5 to 6 mm long knots. When the suture reaches the fibrous trigone, the anteroseptal commissure

### **Figure 3.** *The original and modified technique of Kay annulopasty.*

is inverted on a teflon felt pledget; in the second suture, each knot of the ring interposes with that of the first. The suture ends where it starts, and a teflon felt is attached to the pledget. The degree of narrowing of the annulus can be measured from 25 to 29 mm using a mechanical valve sizer or Hegar dilator, depending on the patient's body surface area. Note that mild stenosis is better tolerated than regurgitation. When performed routinely, the valve can be tested by injecting cold saline into the right ventricle using a bulb syringe (**Figure 4**) [44].

**Figure 4.** *De Vega Annuloplasty.*

**Figure 5.**

*The several modified techniques of De Vega annuloplasty.*

As a result of gliding effect recurrent TR secondary to Bowstring phenomenon is seen after classical De Vega annuloplasty often in the setting of moderate to severe regurgitation. There are several modifications of classical De Vega annuloplasty for example, Revuelta and Garcia-Rinaldi, Dubost, Sagban, and Sarray and Duarte (**Figure 5**) [45].

### *5.1.3 Carpentier ring annuloplasty*

The next technique is ring annuloplasty, introduced by Carpentier in 1971. This is where a rigid or semirigid ring is introduced to control the dilatation of the annulus [39].

A rare complication that deserves focus is injury to the right coronary artery (RCA). Plications caused by aggressive reduction of the tricuspid annulus or deep penetration of purulent string sutures may impair RCA flow [37]. Note that severe arrhythmias, persistent ST elevation on electrocardiogram, or RV dysfunction following cardiopulmonary bypass would affect the RCA. Prompt grafting of the distal RCA or removal of the annuloplasty band is an effective strategy to deal with this rare complication, but early recognition is key for good outcomes [37].

A 2014 meta-analysis compared these techniques and found bicuspidization or the Kay method to be associated with a higher risk of recurrent TR. Still, ring annuloplasty was found to give better results in reducing the risk of recurrence. There was no significant difference in late survival rates, although ring annuloplasty provided significant reduction in early mortality [46]. A more recent 2020 meta-analysis concluded that mortality and TR incidence rates were comparable among ring and suture. Other flexible rings were found to have a higher TR ratio than rigid rings. However, this systematic review excluded articles with primary TR. There is still a limited number of suitable research and a lack of large randomized studies (**Figure 6**) [47].

### **5.2 Leaflets maneuvers**

As described by Castedo et al., other approaches include edge-to-edge repairs, like the Alfieri repair, and DeVega-style purse-string suturing techniques to reduce the anterior and posterior parts of the annulus [48, 49].

There have been some auxiliary techniques to increase ring annuloplasty methods, particularly in leaflet tethering formed by right ventricular dilatation and annulus enlargement. Enlarging the anterior leaflet with a pericardial patch increases leaflet coaptation and provides leaflet mobility (**Figure 7**) [50].

*Tricuspid Valve Repair DOI: http://dx.doi.org/10.5772/intechopen.108821*

**Figure 7.** *The anterior leaflet of TV is enlarged by using a pericardial patch.*

Double-orifice valve repair is achieved by approximating the free edges of the septal and newly formed anteroposterior leaflets. This is very effective in dealing with complex acquired TR (**Figure 8**) [51].

The 'clover' technique consists of stitching together the middle point of the free edges of the tricuspid leaflets, producing a clover-shaped valve (**Figure 9**) [52].

Combination of some factors like the technique of the operation, decision of annuloplasty type, unrecognized severe leaflet tethering area mismatch between the leaflets and the annuloplasty ring. In cases of severe tethering enlargement of posterior and anterior leaflet can be used. However there is no evidence that this is superior to tricuspid valve replacement [50].

Recurrent TR is probably due to a combination of factors: operative technique, type of annuloplasty used, unrecognized severe tethering of the leaflet, and

### **Figure 8.** *Double orifice technique like in Alfieri technique.*

**Figure 9.** *The stages of clover technique.*

mismatch between the area of the leaflets and the area of the annuloplasty ring. Some surgeons advocate patch enlarging the anterior and posterior leaflets in cases of severe tethering but there is no evidence that this is superior to tricuspid valve replacement [50].

### **6. Discussion**

In the absence of concurrent tricuspid valve repair, the incidence of TR after mitral valve surgery is somewhat dependent on the MR mechanism. A US study on 5223 patients reported worse survival rates at a 4-year follow-up of TR, independent of age, right and left ventricular systolic function, or right ventricular diameter. TR has been associated with less survival times in ischemic or non-ischemic cardiomyopathy with or without heart failure symptoms [32, 53]. Matsuyama et al. followed up 174 patients for 8 years and found that only 16% who underwent non-ischemic degenerative mitral valve surgery without tricuspid valve surgery developed 3 to 4 TRs [54]. TR seems much more common in patients who had

### *Tricuspid Valve Repair DOI: http://dx.doi.org/10.5772/intechopen.108821*

mitral valve repair due to functional ischemic mitral regurgitation. Matsunaga et al. investigated 70 patients who underwent mitral valve repair due to functional ischemic mitral regurgitation and found that 30% (21/70) had at least moderate TR before surgery. Postoperatively, moderate TR increased by 25% in 1 year, 53% in 1 to 3 years, and 74% at the 3-year follow-up [55].

Even after successful mitral valve repair, significant residual tricuspid valve regurgitation contributes to poor postoperative hemodynamic outcomes. King et al. found high early and late mortality rates in patients who required tricuspid valve surgery after mitral valve operation. The authors encouraged liberal use of tricuspid annuloplasty in the first mitral valve surgery. Surgical series have demonstrated significant improvement in recurrent TR, survival, and event-free survival rates with successful tricuspid valve repair (primarily when combined with other valve surgeries) [56].

Rigid annuloplasty rings appear to have lower TR recurrence rates than DeVega and flexible band annuloplasty [57]. Algarni et al. compared rigid rings with flexible bands in 713 TV annuloplasty patients in 2020. The authors found that the type of TV annuloplasty did not affect survival or tricuspid valve reoperation. However, there was a trend of higher cumulative incidence of recurrent moderate TR with flexible bands compared to rigid rings [58].

Dreyfus et al. suggested that annular dilatation measuring 70 mm or more during mitral valve repair surgery is an indication for annuloplasty, even in the absence of TR. The authors also demonstrated that TR was increased by at least 2 degrees in 45% of patients undergoing isolated mitral valve repair, supporting the perspective that tricuspid dilatation is a progressive process that often warrants preventive surgical treatment [18]. Singh et al. found no difference in survival or need for TV reoperation over 10 years of follow-up with TV repair compared to tricuspid valve replacement in patients with organic TR. Tricuspid valve repair is associated with better perioperative, midterm, and event-free survival rates than TV replacement in patients with organic tricuspid disease. TV replacement demonstrated higher mortality. The authors suggested that the higher perioperative mortality with replacement may be due to a hard object (the tricuspid valve) in a deformable lowpressure cavity (the right ventricle), resulting in right ventricular dysfunction and a low-output state perioperatively. The authors concluded that there was no difference in terms of functional class among the groups, although the patients had fewer recurrent TRs with repair versus replacement (62% versus 95% had mild or less TR at the final echocardiographic follow-up) [2].

Due to the significant risks of isolated tricuspid valve surgery and the poor prognosis of TR, less invasive approaches like robotic or endoscopic methods or innovative approaches like transcatheter have been needed. Currently, their use is not as common as mitral procedures, as the anatomical features of the tricuspid valve and associated apparatuses make TR treatment with minimally invasive surgery and transcatheter treatment more difficult [59, 60]. Even though severe TR is largely associated with mortality, patients with normal ventricular function can live for years, even decades, without the tricuspid valve. Arbulu et al. performed tricuspid vulvectomy without changing the tricuspid valve in patients with infective endocarditis secondary to IV drug addiction. During long-term follow-up, most patients (37 of 55; 67%) did not require TV replacement, and only a small number of patients without TV developed severe and permanent right ventricular dysfunction. Therefore, if there is only one underlying cardiovascular disease responsible for TR, this may be more important in patients with secondary TR [61].

Gursoy et al. reported that female sex, low preoperative functional capacity, low body surface area, enlarged left atrial size, enlarged right ventricular size, and increased square root of left ventricular mass index were effective on functional TR progression. After these parameters were studied in a multivariate logistic

regression analysis, only female sex and left atrial size were found to be independent risk factors [62].

The recurrence of significant TR after tricuspid annuloplasty is around 8 to 15% at 1 month after surgery, depending on various factors (e.g., preoperative TR severity, pulmonary hypertension, RV dilation, pacemaker, LV dysfunction, increased LV remodeling, severe tethering of tricuspid leaflets, or the DeVega technique instead of ring annuloplasty). Most of randomized and observational researches have shown that particularly in patients with severe tricuspid annular dilatation or pulmonary hypertension, repair the valve with ring annuloplasty techniques are more durable than suture annuloplasty ones. Long-term survival after tricuspid valve surgery for severe TR is influenced by a variety of preoperative factors like advanced heart failure symptoms, comorbidity, and end-organ dysfunction, rather than the type of surgery or the cause of TR. Ring annuloplasty may be associated with better results compared to the DeVega technique. The results of annuloplasty alone have not always been consistent. This may be associated with the degree of narrowing of the tricuspid opening, among other factors; thus, it has been recommended to reduce the size of the tricuspid annulus to prevent recurrent TR, considering the patient's body size [63].

The ESC 2017 guidelines recommend ring annuloplasty as the preferred modality for STR. Besides, in cases of severe tethering or severe enlargement of the annulus, replacement should be considered. Still, a very recent 2020 meta-analysis found no comparable differences among these techniques. There is still a lack of adequate research on valve interventions in TR, so the most effective intervention has yet to be clarified [64].

### **7. Conclusion**

Intervention for the tricuspid valve disease has entered a new era with evolving guidelines and the development of new surgical annuloplasty devices and techniques, as well as conceptual transcatheter options. Still, the implementation of such novel techniques requires a significant infrastructure and increased costs. The current guidelines now emphasize surgical repair of functional tricuspid regurgitation during left-sided valve intervention, even during the repair of severely enlarged annulus in the absence of significant tricuspid regurgitation. The newly developed annular rings have been redesigned to protect the transmission system from adverse effects and to better mimic or preserve the normal tricuspid geometry. Finally, there is now an increasing early experience with new transcatheter approaches for managing very high-risk patients with advanced tricuspid valve disease. Regarding repair, the findings tend to increasingly favor rings, and among these, rigid rings that preserve the geometry.

According to our opinion, as mentioned above, it is very clear that if the patient has a severe TR, it is not true to left it as it is. If the patient has operation indication due to mitral valve disease, transseptal approach from right atrium with bicaval cannulation will be helpful for both valve intervention. By this way the surgeon consider to minimize the aortic cross clamp time. However which technique will be chosen is up to the some factors like experience of the surgeon, limitation of the sources, the degree of the regurgitation and the size of the TV annulus and right ventricle. If you don't have any annular ring for plasty, De Vega, Kay annuloplasty techniques or the modifications can be preferable. Also using teflon felt or pericardial patch like a ring is the other choices. In De Vega technique we use the same sizer with the replaced prostetic mitral valve for the reducing tricuspid annulus. If the patient has minimum or moderate TR also this kind of simple or particle techniques

*Tricuspid Valve Repair DOI: http://dx.doi.org/10.5772/intechopen.108821*

also can be preferable. In severe TR, ring annuloplasty has better middle and long term results then the others. Annuloplasty ring sizers can be use or one or double size larger then the prosthetic mitral valve can be used for the TV annular ring. In my opinion after the TV repair testing by saline injection must be done but the result is not certain for the future progress of the valve. Again to our consideration and observation TV intervention with the mitral valve intervention does not effect the early operation mortality and morbidity.
