Ebstein malformation of the tricuspid valve: Current concepts in management and outcomes

Abstract

Ebstein anomaly is a myopathy of the right ventricle that results in variable degrees of failure of delamination of the tricuspid valve leaflets from the underlying endocardium, leading to severe tricuspid valve regurgitation and some degree of right ventricular dysfunction. In neonates or infants who remain in congestive heart failure or profoundly cyanotic while receiving appropriate medical therapy, operation is required. Current strategies include biventricular or single-ventricle repair. In children and adults, medical management may be used, but most patients eventually require surgery. Tricuspid valve repair is preferred; we believe the cone repair is the most anatomic repair and is the operation of choice. Tricuspid valve replacement may be necessary in cases in which the valve is not repairable. A bidirectional cavopulmonary shunt is useful in patients with severe right ventricular dilatation and/or dysfunction. Transplantation rarely is necessary.

Complex Ebstein's Malformation: Defining Preoperative Cardiac Anatomy and Function

“…Although numerous procedures are described, in the literature, for tricuspid valve repair in Ebstein's malformation, the closest to an “anatomic repair” is the “cone reconstruction” as described by da Silva et al . According to this procedure, the anterior and inferior tricuspid leaflets are detached at the annulus followed by mobilization of the muscular and fibrous attachments between the body of the leaflets and the underlying free wall and septum.…”

“…It can be performed with a low mortality and morbidity and is followed by clinical improvement in the majority of patients, a low incidence of reoperation and no need for tricuspid valve replacement . Relative contraindications for this operative procedure include: neonates, older age (>50 years), moderate or greater elevation in pulmonary arterial pressures, significant left ventricular dysfunction (ejection fraction <30%), complete failure of delamination of the septal and inferior leaflets with poor delamination of the anterior leaflet, severe right ventricular enlargement and severe dilatation of the true tricuspid annulus …”

“…Ebstein's malformation is defined as a myopathy of the right ventricle causing variable degrees of failure of delamination of the valve leaflets from the adjacent myocardium . It has a highly variable morphology, including: (a) adherence of the tricuspid valve leaflets to the fibrous tricuspid valve annulus and partly to the underlying myocardium (failure of right atrioventricular embryonic valve delamination), (b) downward displacement from the atrioventricular junction of the tricuspid leaflets, toward the body or the apex of the right ventricle, (c) dilation of the right ventricle between the anatomic and the functional tricuspid annulus (atrialized right ventricle) with consecutive hypertrophy and thinning of the ventricular wall, (d) fenestrations and tethering, more common in the anterior leaflet, which is the largest, occurring in varying degrees to the other leaflets (e) dilatation of the anatomic tricuspid annulus, (f) myopathy of the right ventricle, associated with thinning of the wall and an absolute decrease in the number of the myocardial fibers .…”

Congenital Heart Defects in Adults : A Field Guide for Cardiologists

“…TR reduces the forward stroke volume of the already hypoplastic functional RV. The atrialized RV balloons out during atrial systole, acting as a passive reservoir rather than participating in coordinated atrial contraction, thus impeding atriosystolic filling of the RV [38]. The small functional RV is often less compliant than the LV, favoring right-to-left atrial shunting.…”

“…Over time, there is RV dilation and thinning of the free wall, both from TR [33] and possibly from an inherent myopathy [38]. With severe RV enlargement, the ventricular septum shifts leftward adversely affecting LV filling [33].…”