**7. Surgical treatment**

## **7.1 Historical evolution**

In the beginning, the surgical procedures for Ebstein's anomaly treatment included systemic-pulmonary anastomosis (Blalock-Taussig and Potts-Smith) closure of atrial septal defect, and anastomosis of the superior vena cava to the right pulmonary artery (Glenn operation, bidirectional cavopulmonary shunt (BCPS)) [33–36].

In 1960, Weinberg et al. reported the first successful Glenn operation for Ebstein's anomaly [36]. However, despite the reported improvement of cyanosis and reductions in the patients'symptoms, Weinberg et al. were cautious in their conclusions, leaving open questions regarding the procedure's effectiveness.

In 1962, Barnard and Schrire reported valve replacement in a patient with Ebstein's anomaly who was the first survivor of tricuspid valve regurgitation correction [37]. In this procedure, part of the valve prosthesis ring was sutured in the right atrium proximally to the coronary sinus—a maneuver intended to avoid atrioventricular block.

#### *Ebstein's Anomaly DOI: http://dx.doi.org/10.5772/intechopen.104670*

In 1964, Hardy et al. [38] reported the first successful performance of tricuspid valve repair with transverse plication of the RV atrialized portion. The technique utilized by Hardy et al. had been previously described by Hunter and Lillehei in 1956 [39]. Bahnson et al*.*, at the University of Pittsburgh, published the successful application of the same repair technique and described important anatomical findings in Ebstein's anomaly specimens in 1965 [40].

The tricuspid valve replacement presented less-than-ideal results with 54% mortality reported by the international cooperative study published in 1974 [41]. Similarly, poor results were also reported by Lillehei et al*.* [42] and in the published experience of the Mayo Clinic [43].

Danielson et al. developed a modification of Hardy's technique, to which was added the posterior tricuspid annuloplasty and the right atrium reduction plasty [44]. Similar to Hunter and Lilelehei's technique, this procedure comprises transverse plication of the atrialized portion of the RV, leading to an approximation of the displaced leaflets and the true tricuspid annulus, obliterating the atrialized right ventricle. Next, the posterior part of the tricuspid annulus is plicated to further reduce the tricuspid annulus circumference. This technique became one of the most used surgical repair techniques for the treatment of Ebstein's anomaly. The Mayo Clinic group accumulated a great deal of experience with Danielson's procedure, however, 36–65% of cases still required tricuspid valve replacement [45–47].

In 2006, the Mayo Clinic reported their 30-year experience with the treatment of 186 children under 12 years old with Ebstein's anomaly [48]. Valve repair using Danielson's technique had a mortality rate of only 5.8% but this repair was possible in only 52 patients (28%), highlighting the limitations of this procedure. In 117 patients (62%), the TV was replaced by prosthesis, while other approaches were used in the remaining 17 children [48].

In 1988, Carpentier et al. [11] described a new technique for valve repair. In contrast to the transverse plication of the atrialized right ventricular chamber described by Danielson et al. (19), Carpentier's procedure involved vertical plication of the atrialized right ventricle. Furthermore, they brought the tricuspid valve leaflets to the anatomically correct level, thus achieving good right ventricular morphology. The tricuspid valve annulus was remodeled and reinforced with a prosthetic ring.

Carpentier's group applied this procedure to the vast majority of anatomical presentations of the disease, but their initial series showed a high hospital mortality rate of 14%, as well as frequent long-term complications [11]. The experience of the Carpentier group, representing the second-largest published series, included an overall mortality rate of 9% [49].

Quaegebeur et al. [50] performed a slight modification in this operation without the use of prosthetic ring. They reported that there was no hospital death, but still observed a high incidence of moderate and severe tricuspid regurgitation.

Many additional surgical techniques were developed, but the wide variety of anatomical and pathophysiological presentations of Ebstein's anomaly makes it difficult to achieve uniform results with surgical repair. Among them, we highlighted the Hetzer and the Sebening procedures [51, 52]. Some of these techniques were used to treat many patients and are still used in a few centers and in specific anatomical situations.

Sarris et al. [53] reported the collective results of 179 operations from 13 institutions associated with the European Congenital Heart Surgeons Association, which showed a 13.3% in-hospital mortality rate. However, it should be noted that this rate included operations in newborns, which constitute a higher-risk group. Despite using a variety of available TV repair techniques, they accomplished tricuspid valve repair in only 27.3% of patients, with a hospital mortality rate of 7.1% for this procedure.

## **7.2 The Da Silva Cone procedure**

Starting in 1989, we developed and routinely used a new surgical technique that was initially called conical reconstruction of the TV [54]. The surgical goals of this method included undoing most of the tricuspid valve anatomical defects that occurred during embryological development and creating a cone-like structure from all available leaflet tissue. This procedure is illustrated in **Figure 15** and aimed to cover 360° of the right AV junction with leaflet tissue, allowing leaflet-to-leaflet coaptation [55]. The result is intended to mimic the normal TV anatomy, with leaflet-to-leaflet coaptation, in contrast to previously applied procedures in which a monocusp valve coapts with the ventricular septum muscle [11, 44, 50, 51].

The first 40 patients who underwent this new procedure had a 2.5% mortality rate and none required tricuspid valve replacement. Early postoperative echocardiograms showed a significant reduction of TV regurgitation, while the medium-term follow-up examinations showed substantial clinical improvement and a low incidence of reoperation [56]. We next performed a study with a larger number of patients and longer follow-up [57], with a focus on investigating the need for valve replacement and the recurrence of TV valve failure, which are the problems observed with the techniques of Danielson and Carpentier, respectively [11, 44, 45]. There were four deaths in 52 enrolled patients (7.69%) during the 57 months of mean follow-up with improved tricuspid regurgitation. In addition, the functional area of the right ventricle increased from 8.53 cm2 /m<sup>2</sup> to 21.01 cm2 /m<sup>2</sup> after surgery [57].

#### **Figure 15.**

*Ebstein's anomaly heart illustration (a) shows the displacement of the septal and posterior leaflets of the tricuspid valve, dividing the right ventricle into two chambers—atrialized right ventricle (proximal to the tricuspid valve) and the functional right ventricle (distal to the tricuspid valve). The cone procedure illustration (b) depicts the tricuspid valve leaflet mobilized and reconstructed in a cone-like shape and reattached to the normal atrioventricular junction, and the atrial septal defect closed in a valved fashion with a single stitch. ASD = atrial septal defect, RA = right atrium, ARV = atrialized right ventricle, functional right ventricle (Modified with permission from reference [55]).*

Below, we review the surgical maneuvers that we have used to obtain the best functional tricuspid valve repair in several anatomical variations of Ebstein's anomaly.

### **7.3 Surgical technique**

The operation is performed via median sternotomy, with the institution of a cardiopulmonary bypass through aortic and bicaval cannulation. For myocardial protection, moderate systemic hypothermia (25–28°C) and cold antegrade blood cardioplegia are used, and a subsequent cardioplegia dose is applied at a suitable interval during the cross-clamp period. The main pulmonary artery can be closed by snare placement to maintain a dry RV during valve repair. This also facilitates examination of the TV after repair, when the RV is filled with a saline solution via a bulb syringe or catheter placed inside the RV [58].

The main steps of the cone operation are described below:

*Step 1: Exposure and assessment of the tricuspid valve.*

This is accomplished by transverse right atriotomy with the placement of stay sutures just above the true valve annulus at the 10, 12, and 3 o'clock positions. The sutures at the 10 and 12 o'clock positions go through the pericardium to avoid annular plane distortion. The left heart is vented by the insertion of a catheter across the patent foramen ovale (PFO) or atrial septal defect (ASD).

*Step 2: Mobilization of the tricuspid valve.*

The surgical methods used to achieve TV mobilization in cases of Ebstein's anomaly are chosen according to the degree of anterior leaflet tethering, septal leaflet size, degree of delamination failure of the inferior and septal leaflets, and the axis of the tricuspid opening in relation to the right ventricle outflow tract (RVOT) and to the RV apex. TV mobilization is accomplished by complete sectioning of the abnormal tethering tissues between the tricuspid leaflets and ventricular wall, leaving the leaflet tissues attached to the ventricle only at its distal margin (by normal papillary muscle, cords, or directly to muscle). In most cases, the majority of leaflet tissue is detached circumferentially, except at the 10–12 o'clock positions. This portion usually is attached to the true annulus without tethering to the ventricular wall, thus allowing free movement. In special situations, the leaflets are detached in the full circumference, allowing complete mobilization of the valve. Aggressive detachment of the leaflet down to its distal point is a critical component of this procedure, to free an adequate amount of tissue for cone construction. This also allows sufficient mobility of the leaflet body in the constructed cone, enabling adequate movement during systole and closure with a good coaptation surface.

The anterior and inferior leaflets of the tricuspid valve are mobilized as a single piece (**Figure 16**), starting with an incision at its proximal attachment to the atrioventricular junction (12 o'clock position) and moving clockwise, toward the displaced inferior leaflet. The incision terminates when the inferior leaflet is completely released from its abnormal proximal attachment to the RV wall. This step provides access to the space between these leaflets and the RV wall, allowing the sectioning of all abnormal papillary muscle, myocardial bridges, and chordal tissues that tether these leaflets to the RV wall. The anterior papillary muscle, which is usually positioned at the anteroposterior commissure, must be freed from its more proximal attachment to the RV wall, retaining only the supports near the RV apex. In some cases, the posterior leaflet must be completely released from its abnormal attachments to the RV to allow its medial rotation to join the septal leaflet, composing the septal aspect of the cone.

**(c) (d)**

#### **Figure 16.**

*Anterior and posterior leaflets of the tricuspid valve mobilized as a single piece. (a) Anterior and posterior leaflets anatomy—dotted line shows the displaced and the dashed line shows the true tricuspid annulus, (b) anterior leaflet mobilization, (c) section of posterior leaflet proximal connection to RV wall, and (d) the completely mobilized anterior and posterior leaflets (with permission from reference [58]).*

The TV anteroseptal commissure is approached with the goal of creating a space between the ventricular septum and the septal aspect of the cone, and of moving the opening axis of the tricuspid valve toward the RV apex. An incision is made at the proximal attachment line of the anterior leaflet, approximately 1 cm anterior to the anteroseptal commissure. This incision is continued counterclockwise down to the septal leaflet, which is mobilized to its lateral limit (**Figure 17**). Stay sutures are placed at the leaflet's proximal edge, exposing the subvalvular apparatus of the septal aspect of the anterior leaflet, septal leaflet, and the anteroseptal commissure. The tissues holding the proximal portion of these leaflets to the septum are divided. If the tricuspid valve opens toward the RV outflow tract, it is necessary to mobilize or cut the papillary muscle abnormally attached to the RVOT. The medial papillary muscle is usually related to the anterior and septal leaflet at its commissure, but in some cases, it is fused to the septum and can be deeply freed improving the mobility of that area of the future cone.

#### *Step 3: Cone construction.*

The cone is constructed using all available mobilized tissue, via the vertical suturing of leaflets—both inferior to septal and septal to anterior. A 5-0 polypropylene running suture technique is used for adults, while a 6-0 polypropylene interrupted suture

#### **Figure 17.**

*Anteroseptal commissure mobilization. (a) An incision is made at the proximal attachment line of the anterior leaflet continues anticlockwise (b), mobilizes the medial papillary muscle (c), and reaches the septal leaflet (d), which is mobilized as deep as possible (with permission from reference [58]).*

technique is applied in children. The cone tends to be narrower posteriorly where there is typically less available leaflet tissue, and thus this area must be widened by vertical incision and horizontal suturing of the leaflet tissue in the constructed cone. The septal leaflet is incorporated into the cone such that the septal part of the cone is longer than the septal vertical distance between the final TV hinge line to its distal attachment to the ventricular septum. Importantly, this allows the septal component of the cone to move anteriorly in the process of coaptation with the anterior component of the cone during systole. Furthermore, this prevents tension at the suture line in the septal aspect of the annular attachment of the cone. If there is not enough leaflet tissue, a piece of the autologous pericardium can be added to this region.

The principal methods of septal leaflet incorporation into the cone are as follows:


**(a) (b)**

**(c)**

#### **Figure 18.**

*Septal leaflet incorporation: (a) a vertical suture joins the septal leaflet superior edge to the medial edge of the anterior leaflet, (b) and (c) a second suture line unites the septal leaflet inferior edge to the lateral edge of the posterior leaflet. In cases with a small septal leaflet, it is combined with the completely detached posterior leaflet by a vertical suture (d), followed by a horizontal suture (e). V = vertical suture, H = horizontal suture (with permission from reference [58]).*

#### *Step 4: Plication of the right ventricle and the true tricuspid annulus.*

This step begins with vertical plication of the thin and attenuated RV-free wall. This portion of the atrialized RV is usually aneurysmal and its limits are defined by the triangle formed by the line of attachment of the displaced inferior tricuspid leaflet, the posterior ventricular septal edge, and the posterolateral area of the true tricuspid annulus. RV plication begins with the placement of a 4-0 polypropylene stitch at the distal apex of this triangular-shaped area, and the suture is continued toward the atrioventricular junction, excluding all of the aneurysmal atrialized RV. Initially, for vertical RV plication, we used a 4-0 polypropylene running suture in two layers with gentle superficial bites to avoid coronary injury or distortion. Recently, we modified this technique, placing interrupted 4.0 polypropylene sutures in multiple places to achieve the vertical plication of the RV atrialized portion. This interrupted suture technique is more often used in children. The vertical plication reduces the true tricuspid annulus at the atrioventricular junction. If further reduction is required, sutures are placed first at the anteroseptal and then at the anteroposterior position of the true tricuspid annulus. The true tricuspid annulus must be reduced such that it matches the proximal circumference of the cone. These multiple plications are important to prevent the right coronary artery distortion or kinking that can occur with a large TV annular reduction at a single site. Additional plication with interrupted sutures is applied to the area where the leaflets were tethered to the RV wall, to prevent anterior wall bulging and dilation of the RV. This maneuver mimics the usual trabeculation of the RV.
