Fig. 14.1
Carpentier classification. Carpentier et al. proposed a classification system based on size of functional RV and adequacy of the anterior leaflet for repair [9]
14.4 Indication and Timing for Operation
Observation alone is usually advised for asymptomatic patients with no right-to-left shunting and only mild cardiomegaly. Regarding indications for surgery in older children and adults, ACC and AHA guideline showed the precise orientation [10]. As long as this guideline, the timing of operation indicates symptoms (dyspnea or palpitation), deteriorating exercise capacity, progression of atrial or ventricular arrhythmia, and cyanosis. The degree of tricuspid regurgitation does not correlate with symptoms, but as time passes, left ventricular dysfunction often appears as symptoms develop.
14.5 Catheter Intervention
The importance of an associated atrial septal defect is reflected in the natural history of EA. Progressive tricuspid valve dysfunction and reduced right ventricular compliance lead to elevated right atrial pressure, which in turn promotes right-to-left shunting at the arterial level with concomitant systemic hypoxia [11]. This clearly has implications in terms of paradoxical embolization in those patients with interatrial defects. The use of percutaneous closure device to ameliorate systemic hypoxia complicating right-to-left shunting through an interatrial defect has been safely performed in a number of clinical settings. Such examples include hypoxia-complicating atrial shunting in right ventricular infarction, prior to and following pneumonectomy, with use of high positive-pressure ventilation, following left ventricular assist device insertion, and in the platypnoea-orthodoexia syndrome [12]. Percutaneous device closure of both atrial septal defects, up to 40 mm in diameter, and patent foramen ovale has been demonstrated to be a safe, with excellent, outcome [13]. One of the major concerns regarding percutaneous device closure of interatrial defects in those patients with a hypoplastic right ventricle, characteristic of EA, is the precipitation of right heart failure. This reflects the possibility that the right ventricle may not be able to tolerate the additional volume loading that inevitability complicates interatrial defect closure in the setting of right-to-left shunting.
14.6 Surgical Intervention
The recommended indications for surgical intervention in EA in the adult are based on recommendations from the Canadian and European guidelines [14, 15]. Also it is important in situations as below:
Deteriorating functional class or exercise capacity, NYHA classes III and IV
Paradoxical embolism
Increasing heart size as manifested by increase in cardiothoracic ratio to >0.65
Progressive right ventricular dilatation or reduction of systolic function
Sustained atrial flatter or fibrillation or arrhythmia secondary to an accessory pathway
Important cyanosis (oxygen saturation < 90%)
In borderline situations, the ability to reconstruct the tricuspid valve, as determined by echocardiography, makes the decision to proceed with operation easier. A biventricular repair is usually possible, but in some circumstances when significant left ventricular dysfunction has occurred, cardiac transplantation may be the best option; however, it is a very limited selection in Japan. The vast majority of patients with EA can undergo successful biventricular repair, especially for adult patients. However, the one and a half repair or univentricular repair (Fontan procedure) can be an effective strategy if the patient has severe RV dysfunction after the agressive annuloplasty of tricuspid valve.
14.6.1 Tricuspid Valve Repair and Replacement
Tricuspid valve repair is based predominantly on a satisfactory anterior leaflet; thus significant abnormalities of the leaflet may compromise the result. Numerous valvuloplasty techniques have been described since the first report on Hunter and Lillehei [16]. Most repair techniques address the abnormal TV in a manner that focuses on the concept of monocusp repair. Monocusp repair depends on an adequate anterior leaflet with a freely mobile leading edge that allows coaptation with the ventricular septum. Significant degree of RV or annular dilatation or significant tethering of the anterior leaflet can preclude successful repair. In the early report of Danielson and colleagues, the plication of the free wall of the atrialized right ventricle, posterior tricuspid annuloplasty, and excised redundant right atrial wall combined with monocusp repair were described [17] (Fig. 14.2). Carpentier and colleagues focused on mobilization (surgical delamination) of the anterior leaflet with annular reattachment, resulting in an anterior leaflet monocusp repair [18] (Fig. 14.3). Hetzer and colleagues reported their operative technique for EA that they individualized depending on the specific anatomy in a series of 68 patients (Fig. 14.4). They conclude that all morphologic types of EA are amenable to repair (no tricuspid replacements at initial operation) and that satisfactory long-term ventricular function and functional outcome can be obtained, even in the most severe cases [19].
Fig. 14.2
Danielson repair. Mattress sutures passed through pledgets of Teflon felt and used to pull tricuspid annulus and tricuspid valve together (left). Suture is placed in atrialized portion of right ventricle and tied down sequentially to plicate aneurysmal cavity (right) [20]
Fig. 14.3
Carpentier repair. (a) Detachment of the anterior leaflet and section of the muscular bands in order to individualize the lateral papillary muscle. Dashed lines indicate the limits of the atrialized chamber. (b) Longitudinal plication of the atrialized chamber from the apex of the right ventricle to the tricuspid annulus. Subsequently, the tricuspid annulus is reduced. (c) Reattachment of the anterior leaflet on the true annulus with a clockwise rotation [21]
Fig. 14.4
Hetzer repair. Schematic presentation of a cross-sectional (a, c, e) and surgeon’s views (b, d) of the intraoperative findings and the surgical technique applied. The pathologic finding corresponds to Ebstein’s anomaly of Carpentier type B [12], with the displaced septal (s) and posterior (p) leaflets toward the apex of the right ventricle (RV). Leaflet displacement creates an atrialized chamber (atr. ch.) below the anatomic tricuspid annulus. There is a large, mobile anterior leaflet (a). (c, d, e) The anterior part of the anterior leaflet was chosen for the valve-closing structure. A mattress suture of 3-0 polypropylene pledgeted with autologous pericardium is passed from the anterior leaflet annulus to the atrialized septum just below the natural tricuspid annulus. A row of these sutures is added toward the posterior annulus [22]
14.6.1.1 Cone Reconstruction (Figs.14.5 and 14.6)
Fig. 14.5
Ebstein’s malformation—the cone procedure [23]. The anterior and posterior leaflets are detached from the annulus as a single unit, mobilized from their anomalous attachments in the RV, and rotated in a clockwise fashion to be sutured to the septal border of the anterior leaflet. The principle of CR is complete surgical delamination including septal leaflet as possible and recruitment of all undelaminated leaflet tissue
Fig. 14.6
(a) Appearance of valve of Ebstein anomaly. There is no coaptation zone between leaflets. #: anterior leaflet, *: septal leaflet. (b) Plastering of the septal leaflet. *: septal leaflet. (c) Plication of atrialized ventricle. (d) Construction of cone using three leaflets. Cone will attach to the annulus for completion of the cone procedure
However the numerous valvuloplasty techniques have been described, tricuspid valve repair in dysplastic anterior tricuspid valve is very difficult. A further extension of the Carpentier repair has been proposed by da Silva and colleagues and termed the cone reconstruction (CR) [24]. The anterior and posterior leaflets are detached from the annulus as a single unit, mobilized from their anomalous attachments in the RV, and rotated in a clockwise fashion to be sutured to the septal border of the anterior leaflet. The principle of CR is complete surgical delamination including septal leaflet and recruitment of all undelaminated leaflet tissue, which is reattached at the true right atrioventricular junction, creating a 360-degree “leaflet cone.” Leaflet-to-leaflet approximation is done with interrupted monofilament sutures to avoid a purse-string effect, which can decrease the height of the reconstructed leaflet. The atrialized RV is plicated internally from the apex to annulus. The plication typically crosses the true annulus to partially reduce the size of the dilated annulus. During this procedure, care is taken to avoid distortion or compromise of the right coronary artery. Reattachment of the neo-TV to the true annulus is done with interrupted or continuous suture; continuous suture does purse string the annulus, causing further reduction in annular size, which may be desired in some situation. Original corn reconstruction is no indicated ring annuloplasty. The learning curve for CR is steep, and the following steps are the most important. First, the most challenging aspect of CR is surgical delamination. Surgical delamination is complete when all muscular or fibrous attachments between the body of the leaflets and the RV free wall and ventricular septum have been completely taken down. When this is done properly, the only attachments remaining are chordae or direct papillary muscle insertion to the leading edge of mobilized leaflets. Iatrogenic fenestration of the thin RV free wall is easy to do during this process. Sometimes, there are areas of leaflet muscularization. In general, these leaflet segments should be preserved, debulked, and not excised. Heavy muscularization of the anterior leaflet is problematic because of reduced pliability. Second, recruitment of a very diminutive septal leaflet is critical. There must be some septal leaflet present that can be approximated to the other mobilized leaflets to obtain 360 degree of leaflet tissue around the atrioventricular junction. The more diminutive the septal leaflet, the more important it is to have sufficient “other valve tissue” to compensate for this deficiency. Right ventricular plication and annular reduction should be done liberally. Right ventricular plication helps reduce the size of the right ventricle and the annulus in a gradual manner and distributes tension so that it does not all reside at the annulus. The inferior annulus plication is the site of greatest tension and the most vulnerable to right coronary compromise. Also several reports have shown abnormalities of the LV [25]. These abnormalities include abnormal motion of the interventricular septum (IVS) and compression of the LV, which are induced by the enlarged right heart. The enlarged heart also occupies so much space in the thoracic cavity that the lungs are rendered hypoplasia. After free wall resection of the right ventricle, the small right heart helps the IVS motion and the LV function to improve and also provides the lungs with more space to expand immediately after the operation (Fig. 14.7).
