Frank Cetta and Benjamin W. Eidem Mayo Clinic, Rochester, MN, USA Ebstein anomaly and tricuspid valve dysplasia are the two most common congenital malformations of the tricuspid valve. Ebstein anomaly was initially described in 1866 after an autopsy by Wilhelm Ebstein showed a unique abnormality of the tricuspid valve [1]. The reported prevalence of Ebstein anomaly is 1–5 per 100,000 live births with an equal distribution between the sexes [2–4]. Yet, it was not until 1950 that Ebstein anomaly was clinically recognized [5]. The tricuspid valve is composed of three leaflets, the anterior, septal, and inferior (a.k.a. posterior) leaflets. As the name implies, the septal leaflet has connections to the ventricular septum. It is typically displaced toward the cardiac apex in Ebstein anomaly when compared with the normal heart. The anterior leaflet is usually large and redundant and has been described as “sail‐like” (Figure 14.1). The inferior leaflet is positioned along the inferior aspect of the right ventricular cavity. It lies adjacent to the diaphragmatic surface of the heart (Figures 14.2 and 14.3). In Ebstein anomaly there is failure of proper delamination of the tricuspid valve leaflets from the ventricular myocardium. Although Ebstein anomaly is considered a disorder of the tricuspid valve leaflets, it is more accurately described as an aberration in myocardial development and essentially is a cardiomyopathy [4]. The right ventricle in Ebstein anomaly rarely has normal morphology or function. The hallmark anatomic feature of Ebstein anomaly is displacement of the septal and inferior leaflets away from the crux of the heart and the atrioventricular junction (Videos 14.1 and 14.2). During cardiac development, leaflet displacement results from failure to fully separate from the underlying ventricular wall. The normal leaflet separation process is referred to as “delamination.” Normal delamination begins at the tips of the embryonic leaflets and proceeds toward the base of the leaflet at the atrioventricular junction. The normal delaminated tricuspid valve leaflet will have a hinge point near the true anatomic annulus (Figure 14.4). Due to the arrest in proper delamination of the tricuspid valve leaflets, patients with Ebstein anomaly have varying degrees of apical displacement of the septal leaflet with accompanying anterior rotation of leaflet tissue towards the right ventricular outflow tract. The displacement seen in Ebstein anomaly is not simply a linear shift of the tricuspid valve towards the apex but actually a spiral rotation of the leaflets anteriorly towards the right ventricular outflow tract (Figure 14.5) [6]. In hearts with Ebstein anomaly, the septal and inferior leaflets are usually the most dramatically involved. In contrast, the anterior leaflet is formed at a different stage in cardiac development. As a result, the junctional hinge point of the anterior leaflet usually remains at the true anatomic annulus. However, the anterior leaflet is far from normal and is usually very large and sail‐like (Video 14.3). In cases of Ebstein anomaly that are associated with pulmonary atresia with an intact ventricular septum, the anterior leaflet may appear to be more normal. More commonly, the anterior leaflet has attachments to the free wall of the right ventricle resulting in varying degrees of tethering. These attachments may be thin chordae or they may be heavily muscularized; they play an important role in the novel repair techniques wherein the surgeon mobilizes the leaflet tissue and reattaches it to the anatomic annulus. The distance that the septal leaflet is displaced from the true anatomic annulus towards the apex of the right ventricle can be quantitated echocardiographically. This measurement has been referred to as the “displacement index” (Figure 14.6). Although hearts afflicted by Ebstein anomaly have many other leaflet and myocardial abnormalities, the displacement of the septal leaflet has become the hallmark, although not exclusive, feature in the diagnosis of Ebstein anomaly. This is discussed further in the section “Echocardiographic features of Ebstein anomaly.” Figure 14.1 Pathologic specimen demonstrating a “sail‐like” anterior leaflet of the tricuspid valve in Ebstein anomaly. Note the translucent nature of the leaflet, its large size, and the multiple chordal attachments to the free wall of the right ventricle. Source: Courtesy of Dr. William Edwards. © Mayo Clinic Foundation, all rights reserved. Figure 14.2 Right atrial view of a tricuspid valve demonstrating the normal position of the anterior, inferior, and septal leaflets. Also note the proximity of the right coronary artery (RCA) as it traverses the right atrioventricular groove. Source: Courtesy Dr. William Edwards. © Mayo Clinic Foundation, all rights reserved. Patients with Ebstein anomaly present at many ages. The most severely affected will present in the newborn period. Newborns with severe Ebstein anomaly have massive cardiomegaly and significant cyanosis due to right‐to‐left shunting at the level of the atrial septum [7,8]. Neonates with Ebstein anomaly can be difficult to manage due to increased pulmonary vascular resistance. In the most severe cases, the dysfunctional right ventricle cannot generate enough pressure to adequately open the pulmonary valve, resulting in functional pulmonary valve atresia [9,10]. This leaves the patient extremely cyanotic due to right‐to‐left shunting across the patent foramen ovale. As the pulmonary vascular resistance drops, antegrade flow across the pulmonary valve typically occurs. The cyanosis can steadily improve due to less tricuspid insufficiency and less right‐to‐left shunting at the atrial level. In rare cases of neonates with associated pulmonary valve regurgitation, a “circular circulation” is established which increases cyanosis, decreases systemic output, and worsens prognosis. Figure 14.3 Pathologic specimen of the right ventricular aspect of the tricuspid valve demonstrating anterior (Ant), inferior (Inf), and septal (Sep) leaflets. Note the multiple chordal attachments to the septum. Source: Courtesy of Dr. William Edwards. © Mayo Clinic Foundation, all rights reserved. Figure 14.4 (a) Diagram of normal delamination from the myocardium of a tricuspid leaflet at the level of the endocardial cushion (EC). (b) Diagram demonstrating failed or incomplete delamination of the tricuspid valve (TV) leaflets present in Ebstein anomaly showing an “atrialized” right ventricle. This is below the level of the true anatomic annulus and above the level of leaflet coaptation. RA, right atrium; RCA, right coronary artery; RV, right ventricle. Source: With permission, © Mayo Clinic Foundation, all rights reserved. Depending on the associated anomalies, infants with Ebstein anomaly typically do not need surgical intervention in the newborn period. On the other hand, those patients with the most severe forms of Ebstein anomaly with severe tricuspid regurgitation or severe right ventricular obstruction or atresia will need intervention. In these cases, palliation with a systemic‐to‐pulmonary artery shunt can allow the patient to grow [11]. Oversewing the tricuspid valve with a fenestration (Starnes procedure) in conjunction with a central shunt has also been used for palliation [12]. Novel tricuspid valve repair techniques may have a role in these patients but to date most neonates with severe Ebstein anomaly have had a poor outcome. Cardiac transplantation is another consideration for the most severe cases. Ebstein anomaly can be readily diagnosed in utero with fetal echocardiography utilizing the four‐chamber view that delineates abnormalities of the tricuspid valve (Video 14.4). Echocardiography has impacted the age of diagnosis for patients with Ebstein anomaly. In 1979, Giuliani et al. reported that one‐third of patients with Ebstein anomaly were diagnosed before 4 years of age [13]. Another 40% of patients were diagnosed by age 19 years. However, cases have been reported of >60‐year‐old patients who were misdiagnosed with “mitral valve prolapse” based on clinical exam alone. Ultimately these patients had an echocardiogram, and the diagnosis was revised to Ebstein anomaly. The clinical examination of a child with Ebstein anomaly can vary. The cardiac impulse is normal in patients with milder forms of tricuspid malformation and laterally displaced in more severe forms. With severe tricuspid regurgitation a holosystolic murmur is usually present along the left lower sternal border. An ejection murmur of right ventricular outflow obstruction may be present. Patients with mild Ebstein anomaly have normal first and second heart sounds. However, split first and second sounds and/or third or fourth heart sounds may be present [12,13]. The typical auscultation of a patient with Ebstein anomaly has been described as a “multiplicity of sounds.” Cyanosis may be evident but is subtle. Jugular venous distension is not common because the large right atrium and atrialized right ventricle dissipate the “V” wave. However, sometimes the accentuated jugular venous V wave is observed in patients with severe tricuspid regurgitation without an interatrial shunt. Hepatomegaly is uncommon except in patients with advanced right heart failure. The electrocardiogram in these patients will demonstrate right atrial enlargement with large P waves, PR interval prolongation, and a right bundle branch pattern. Wolff–Parkinson–White (WPW) syndrome with overt pre‐excitation evident on the surface electrocardiogram is present in 15% of patients with Ebstein anomaly. The accessory pathway may be concealed and not evident on the surface electrocardiogram. Supraventricular tachycardia (SVT) may occur in up to 30% of patients with Ebstein anomaly. Chest radiography can appear normal in mild forms of Ebstein anomaly. In contrast, in neonates with massive cardiomegaly, the heart can occupy the majority of the chest (Figure 14.7). This can occur in severe cases of Ebstein anomaly and tricuspid valve dysplasia where tricuspid regurgitation is the major hemodynamic abnormality. Impressive right ventricular enlargement is observed echocardiographically. Indications for operation in patients with Ebstein anomaly are summarized in Table 14.1. Ventricular septal defects, tetralogy of Fallot, coarctation of the aorta, and patent ductus arteriosus have all been described with Ebstein anomaly. Left‐sided cardiac anomalies, specifically mitral valve prolapse and noncompaction of the left ventricle, have also been described [14]. In 1987, Benson et al. proposed that the morphology and function of the right heart in Ebstein anomaly alters the left ventricular geometry and in turn its function [15]. It has been shown in neonates with Ebstein anomaly that increased fibrosis is present in the left ventricular myocardium [16]. Therefore, left ventricular dysfunction in Ebstein anomaly is likely a combination of both mechanisms. Figure 14.5 (a, b) Diagram demonstrating several positions of tricuspid valve coaptation in Ebstein anomaly. Note in (b) the rotation of the coaptation point anteriorly into the right ventricular outflow tract. Source: Courtesy of Dr. Robert Anderson. © Mayo Clinic Foundation, all rights reserved. Figure 14.6 Diagram of the “displacement index.” The distance from the hinge point of the anterior mitral leaflet is measured to the hinge point of the delaminated septal tricuspid leaflet. This measurement divided by the body surface area equals the displacement index. A displacement index >8 mm/m2 is diagnostic of Ebstein anomaly. A small functional right ventricle (RV) is present inferior to the coaptation point of the tricuspid valve. RA, right atrium; TVA, tricuspid valve annulus. Source: With permission, © Mayo Clinic Foundation, all rights reserved. Figure 14.7 Anterior/posterior chest radiograph from an infant with severe Ebstein anomaly demonstrating massive cardiomegaly. Source: With permission, © Mayo Clinic Foundation, all rights reserved. Table 14.1 Indications for operation in Ebstein anomaly Functional pulmonary valve atresia or stenosis may be found in up to one‐third of neonates presenting with Ebstein anomaly. In severe Ebstein anomaly, the massive cardiac size compresses the lungs and causes pulmonary hypoplasia. This contributes to the clinical instability of these newborns and complicates their management. Echocardiography has been considered the gold standard for the diagnostic evaluation of patients with Ebstein anomaly [17,18]. The internal cardiac crux, as imaged in the four‐chamber view, is the most consistent imaging landmark in the human heart (Figure 14.8, Video 14.1). The four‐chamber view permits assessment of the septal hinge points of the mitral and tricuspid leaflets. The most sensitive and specific diagnostic feature in Ebstein anomaly is the displacement of the annular hinge point of the septal leaflet (Vv 14.2) [19]. This displacement is appreciated by comparison of the annular hinge point of the anterior mitral valve leaflet with that of the septal leaflet of the tricuspid valve. In normal hearts, there invariably is slight apical displacement of the hinge point of the tricuspid septal leaflet as compared with the mitral anterior leaflet (Figure 14.9). However, in Ebstein anomaly, due to the failure of leaflet delamination, the septal leaflet hinge point is displaced inferiorly towards the apex. The distance between the valve hinge points can typically be measured in either systolic or diastolic still frames in the apical four‐chamber plane. The distance from the hinge point of the anterior leaflet of the mitral valve to the hinge point of the septal leaflet of the tricuspid valve is divided by the body surface area measured in square meters. This is known as the “displacement index.” A displacement index exceeding 8 mm/m2 is a reliable feature to distinguish hearts with Ebstein anomaly from other forms of RV volume overload (see Figure 14.6). In the most severe cases of Ebstein anomaly, the hinge point of the septal leaflet is not visualized in the four‐chamber imaging plane (Video 14.5). This is because the septal leaflet has been rotated anteriorly into the right ventricular outflow tract (see Figure 14.5). In these cases, the displacement index is considered infinite (Figure 14.10) and much of the tricuspid leaflet tissue is in close proximity to the pulmonary valve. Figure 14.8 Severe Ebstein anomaly: (a) pathology specimen, (b) apical four‐chamber echocardiographic image, and (c) cardiac magnetic resonance image. All three images show severe displacement of the tricuspid valve (TV) leaflets into the apex of the right ventricle (RV) with severe enlargement of the right atrium (RA) and atrialized portion of the RV. The left ventricle (LV) is compressed due to the massive right‐sided volume overload. The anterior TV leaflet has multiple muscular tethering points along its length. The septal leaflet is not delaminated in all three images. aRV, atrialized right ventricle; LA, left atrium. Source: With permission, © Mayo Clinic Foundation, all rights reserved. The displacement index is a simple quantitative measurement to assist in the diagnosis of Ebstein anomaly; but it is not the entirety of the diagnosis. As previously mentioned, patients with Ebstein anomaly have failure of delamination of the inferior and anterior leaflets. These leaflets have abnormal tethering and muscularization of the chordal apparatus. In some cases there may appear to be complete absence of the septal and inferior leaflets. Ebstein anomaly is a disease of the right ventricular myocardium and careful assessment of the structure, size, and function of the right ventricle is important, in addition to detailed interrogation of the leaflet morphology. Echocardiography is uniquely suited for evaluation of the tricuspid valve apparatus and support structures. However, assessment of the severity of tricuspid regurgitation in Ebstein anomaly has multiple pitfalls. Tricuspid regurgitation has been quantitated utilizing criteria established for normal adult hearts [20]. However, quantification of tricuspid regurgitation in patients with Ebstein anomaly is not as straightforward. For example, measurement of the vena contracta in patients with Ebstein anomaly can be difficult. Right ventricular systolic pressure in these patients is usually normal. Therefore, the tricuspid regurgitation jet will appear laminar when evaluated with color flow Doppler. This can be deceptive and cause the observer to underestimate the severity of tricuspid regurgitation due to the lack of an “aliased” region where it is easy to measure the vena contracta (Figure 14.11). The valve leaflets in Ebstein anomaly may have multiple fenestrations and therefore multiple jets of tricuspid regurgitation. This creates further pitfalls in evaluation and quantification of tricuspid regurgitation. Most importantly, the orientation of the valve leaflets is not normal. Many patients with Ebstein anomaly have rotation of the leaflets into the right ventricular outflow tract. This causes the orientation of the tricuspid regurgitation jet to be unusual. The tricuspid regurgitation jet may not be adequately evaluated in the apical four‐chamber view. Instead, the best view of the tricuspid regurgitation jet will be in a modified right ventricular outflow tract view (Figure 14.12). Figure 14.9 (a) Pathology specimen demonstrating the true anatomic annulus (arrow) at the hinge point of the anterior tricuspid valve leaflet. Note in this specimen the failed delamination of the anterior leaflet to the leading edge of the leaflet which is present deep in the apex of the right ventricle near the level of the moderator band. (b) Apical four‐chamber echo image demonstrating a patient with Ebstein anomaly. A displacement index >8 mm/m2 is a consistent hallmark of Ebstein anomaly. aRV, atrialized right ventricle; LV, left ventricle; RA, right atrium; LA, left atrium. Source: (a) Courtesy of Dr. William Edwards. © Mayo Clinic Foundation, all rights reserved. (b) With permission, © Mayo Clinic Foundation, all rights reserved. Figure 14.10 Apical four‐chamber image demonstrating a severe form of Ebstein anomaly. In this image, there appears to be no delamination of the septal leaflet. The anterior leaflet has dense attachments to the free wall of the right ventricle (arrow). In this image, it appears that the right ventricle is entirely “atrialized.” The left ventricle (LV) is compressed due to the right‐sided volume overload. There is massive right atrial enlargement. aRV, atrialized right ventricle; LA, left atrium; RA, right atrium. Source: With permission, © Mayo Clinic Foundation, all rights reserved. Figure 14.11 Apical four‐chamber view demonstrating a patient with Ebstein anomaly and severe tricuspid regurgitation. Note the laminar tricuspid regurgitation color flow due to the wide vena contracta and low velocity. Source: With permission, © Mayo Clinic Foundation, all rights reserved. Many components of the traditional echocardiographic assessment of tricuspid regurgitation in the normal heart may not be as useful in the evaluation of tricuspid regurgitation in Ebstein anomaly. For the same reason that V waves may be absent in patients with Ebstein anomaly and severe tricuspid regurgitation, hepatic vein systolic reversals are usually absent, especially in young patients. The echocardiographer must be astute and utilize multiple imaging planes to adequately assess tricuspid regurgitation in Ebstein anomaly. Figure 14.12 Subxiphoid images from an infant with severe Ebstein anomaly. The functional orifice is also the origin of a single broad jet of regurgitation (arrow). This jet begins near the right ventricular outflow tract and is oriented inferiorly toward the diaphragm. aRV, atrialized right ventricle; L, left; RA, right atrium; RV, right ventricle; S, superior. Source: With permission, © Mayo Clinic Foundation, all rights reserved. Figure 14.13 Apical four‐chamber views that demonstrate the Celermajer index in two patients with Ebstein anomaly. (a) The area of the left atrium + left ventricle + right ventricle below the level of tricuspid valve coaptation is larger than the area of the right atrium + atrialized right ventricle. The Celermajer index in this patient would be <1.0. (b) In contrast, this patient has a Celemajer index >1.0. The area of the right atrium + atrialized right ventricle is larger than the other chambers of the heart. A Celermajer index >1.0, in neonates, correlates with poor prognosis. Source: With permission, © Mayo Clinic Foundation, all rights reserved. In 1992, Celermajer proposed an echocardiographic technique that measured the size of the right atrium (defined as the area above the tricuspid valve coaptation) and divided this by the combined area of the right ventricle below the level of coaptation + left atrium area + left ventricle area (Figure 14.13) [21]. If this index exceeds 1.0, it is a poor prognostic factor [16]. This index has been utilized in neonates and small children; its applicability in older children and adults has not been rigorously studied. The importance of the Celermajer index emphasizes that the right atrium is severely enlarged in many patients with Ebstein anomaly. The area below the true anatomic annulus but above the level of coaptation of the valve leaflets has been referred to as the “atrialized right ventricle” (Figure 14.12). This area of the right heart will have right atrial pressure if one places a pressure transducer in this location. However, since it lies below the anatomic tricuspid valve annulus, the action potential and electrocardiographic signals in this area are those of ventricular myocardium. Recruitment of this area of the right ventricle is one of the benefits of the cone repair technique. The traditional monoleaflet repair technique, introduced by Gordon Danielson at the Mayo Clinic in the 1970s, served many patients with Ebstein anomaly well for decades. When data from these patients were evaluated, 40–50% of patients received a repair that was durable for 15–20 years [22]. However, nearly 60% of patients operated in that era had a valve replacement. Preoperative echocardiography was highly predictive of surgical ability to repair the tricuspid valve with the monoleaflet approach. The most important feature predictive of a durable monoleaflet repair was the mobility of the anterior leaflet. It was critical for at least one‐half of the leaflet to be mobile, free of major tethering to the myocardium, and have a leading edge that would freely coapt with the ventricular septum after repair (Videos 14.6 and 14.7). With this monocusp repair, no attempt was made to delaminate the septal leaflet or form a functionally coapting valve. Instead the “sail‐like” qualities of the anterior leaflet were utilized to create a monoleaflet repair. Unfortunately, the more severe forms of Ebstein anomaly were not amenable to this repair technique. Specifically, when leaflet tissue was rotated anteriorly into the right ventricular outflow tract, that tissue could not be mobilized to form adequate coaptation at the level of the true tricuspid valve annulus. Many patients with severe forms of Ebstein anomaly had a valve replacement in the era prior to the cone repair (Videos 14.8 and 14.9). In the modern era with the “cone technique” originally introduced in Brazil by José DaSilva and extensively modified by Joseph Dearani at the Mayo Clinic, the majority of patients with Ebstein anomaly are now amenable to a successful repair technique. Data from the Mayo Clinic demonstrated that in patients less than 21 years of age, >95% of patients had valve repair regardless of leaflet morphology [23]. One important issue that needs to be addressed for prediction of reparability with the cone technique is muscularization of the leaflet and its support apparatus. The surgeon is able to successfully “delaminate” much of the septal, inferior, and anterior leaflets. Thick muscular chordal attachments to the anterior leaflet and muscularization of the leaflet itself are features that predict a less than acceptable repair. Partial annuloplasty rings are applied to most cone repairs. Unlike the monoleaflet repair, the cone reconstruction permits repair of the valve at the true anatomic annulus (Figures 14.14 and 14.15, Videos 14.10–14.13). The surgeon delaminates the valve tissue, preserving much of the right ventricular myocardium. Supplementation of the leaflets with sutures and patch material are adjuncts. Great care is taken to avoid the right coronary artery and the conduction tissue when the mobilized valve leaflets are attached at the atrioventricular junction. The cone reconstruction dramatically decreases the amount of tricuspid regurgitation in most patients and restores the hinge point of the repaired tricuspid valve to its normal anatomic position. After the cone repair, many of the tricuspid valve leaflets appear thickened when imaged with surface echocardiography. Despite this leaflet thickening, tricuspid valve stenosis has not been a major problem in these patients. In patients with significant right ventricular dilation and dysfunction, a cavopulmonary connection is added to a cone repair in order to reduce the volume load on the right ventricle. This cavopulmonary connection was not utilized as frequently in the era of the monoleaflet repair. However, in the current age, it is employed in 20% of patients, specifically younger patients with significant right ventricular systolic dysfunction. Figure 14.14 Diagram demonstrating the cone repair for Ebstein anomaly of the tricuspid valve. (a) The leaflets are surgically delaminated and brought to the level of the true anatomic annulus. (b) A reduction of the atrialized right ventricle has been performed and the valve is reconstructed to form the shape of a cone. Source: Courtesy of Dr. Joseph Dearani. © Mayo Clinic Foundation, all rights reserved. Figure 14.15 Intraoperative right atrial view during a cone repair for Ebstein anomaly. Note that all three leaflets of the tricuspid valve have been mobilized and are being extended to the level of the true anatomic annulus. Source: Courtesy of Dr. Joseph Dearani. © Mayo Clinic Foundation, all rights reserved. In older patients (>50 years of age), there is a lower threshold for tricuspid valve replacement with a bioprosthesis. Valve replacement should also be considered if more than half of the anterior leaflet has failed to delaminate, or if the leading edge of the anterior leaflet has dense attachments to the right ventricle [24]. In a large series from the Mayo Clinic prior to the cone reconstruction experience, there was no difference in long‐term survival or freedom from reoperation between those patients who had valve repair versus those with replacement [22]. Thus, in older patients, tricuspid valve replacement is a reasonable option. The need for reoperation at 20 years after the operation is approximately 50%. Mechanical prosthetic valves are usually avoided in Ebstein anomaly. Mechanical tricuspid prostheses are avoided due to reduced disk mobility in a large prosthesis, low right atrial and ventricular pressures, and poor right ventricular contractility (creating low opening and closing pressures). Mechanical valve disk immobility may be a nidus for thrombosis despite adequate anticoagulation. The most recent intervention for these patients is percutaneous valve‐in‐valve therapy in those with a dysfunctional bioprosthesis [25]. The use of percutaneous valve technology will hopefully obviate the need for further surgery in many patients (Videos 14.14 and 14.15). Patients experiencing arrhythmias usually have an electrophysiologic study with ablation; prior to surgical intervention and in some centers all patients will undergo electrophysiologic study prior to repair to look for concealed accessory pathways and to ablate them prior to the cone procedure. A Maze procedure can be completed at the time of the tricuspid valve surgery. However, recurrence of atrial arrhythmias after a surgical Maze procedure for patients with Ebstein anomaly is high (50%). In the cone repair era (see next section), the incidence of postoperative arrhythmia is markedly reduced. Cardiac transplantation in patients with Ebstein anomaly is reserved for the most severe cases and when there is concurrent severe left ventricular dysfunction. The first cone repair at the Mayo Clinic was performed in June 2007. In 2013, Anderson et al. [23] reported the outcomes for the first 84 patients, younger than age 21 years. By hospital discharge, 98% of patients had a successful tricuspid valve repair. There was one death (a neonate who died of pulmonary disease) and one valve replacement. The mean age at the time of the valve repair was 10 years (range 5 days to 20.8 years). The first patient repaired in 2007 is doing well in his mid‐20s, now 13 years after the operation. In 2018, Wackel et al, reported that postoperative arrhythmias after cone repair in young patients have been rare (<6%) [26]. Only 7% of postoperative patients had tricuspid valve stenosis (mean gradient >6 mmHg), however 30% of patients had a bidirectional cavopulomnary anasomosis performed during or prior to the valve repair. The following are relative contraindications to cone repair: (i) patient age >70 years; (ii) moderate pulmonary hypertension; (iii) severe left ventricular dysfunction (ejection fraction <30%); (iv) absent septal leaflet; (v) significant muscularization of the anterior leaflet; and (vi) severe tricuspid valve annular dilation with severe right ventricular enlargement and systolic dysfunction (usually in older adults). The current Mayo Clinic experience with cone repair exceeds 350 patients as of September 2019. Holst et al. reported on 235 of those patients and evaluated valve durability and right ventricular remodeling. They found that during a mean follow‐up of 3.5 years, there was a significant reduction in tricuspid regurgitation, a progressive decline in right ventricular size, and a late increase in right ventricular fractional area change after an initial perioperative decline. Most importantly, freedom from reoperation was 98% at 6 years [27]. However, no two Ebstein valves are identical, nor are any two repairs. Optimal timing for surgery is now considered at 4–7 years old, and “waiting for symptoms” should no longer be standard practice for patients with Ebstein anomaly (see Table 14.1). In select patients, the bidirectional cavopulmonary anastomosis (BDCPA) has become an important adjunct to the repair of Ebstein anomaly. It reduces venous return by approximately one‐third to the enlarged, dysfunctional right ventricle and it provides sufficient preload to the left ventricle to sustain adequate systemic perfusion. Indications for BDCPA include: (i) severe right ventricular enlargement and/or dysfunction; (ii) compression of the left ventricle due to a shift of the septum; (iii) moderate tricuspid valve stenosis (mean gradient >8 mmHg) after cone repair; or (iv) right atrial to left atrial pressure ratio >1.5 (an indicator of poor right ventricular function). However, the BDCPA has disadvantages: (i) pulsatility of the head and neck veins; (ii) possible facial swelling; (iii) potential development of veno‐veno collaterals and/or pulmonary arteriovenous fistulae; and (iv) limitation of access to the heart from the internal jugular vein. The use of the BDCPA should be reserved for select patients, but it is a promising option especially in the presence of right ventricular failure. Long‐term implications of a cone repair combined with a BDCPA are not known.
CHAPTER 14
Ebstein Anomaly, Tricuspid Valve Dysplasia, and Right Atrial Anomalies
Epstein anomaly
Introduction and incidence
Morphology and development
Pathophysiology
Clinical presentation
Associated features with Ebstein anomaly
Current recommendations
Earlier operation if valve morphology is favorable for repair
Operate preferably when patients are 4–7 years old
Waiting for symptoms is no longer standard of care
Historical indications for intervention
Decreased exercise tolerance, especially when associated with cyanosis
Progressive right ventricle dilation
Prior to significant right ventricular systolic dysfunction
Onset or progression of atrial arrhythmia
Prior to left ventricular systolic dysfunction
Imaging
Echocardiographic features of Ebstein anomaly
Impact of echocardiography on tricuspid valve repair
Impact of echocardiography on cone repair outcome
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