Cone Reconstruction of the Tricuspid Valve for Ebstein's Anomaly: Anatomic Repair

Abstract

Ebstein's anomaly is a congenital malformation of the right ventricle and tricuspid valve that is characterized by multiple features that can exhibit an infinite spectrum of malformation.1Dearani J.A. O'Leary P.W. Danielson G.K. Surgical treatment of Ebstein's malformation: state of the art in 2006.Cardiol Young. 2006; 16: 12-20Crossref PubMed Scopus (45) Google Scholar Abnormalities of the tricuspid valve and right ventricle include the following: (1) adherence of the tricuspid leaflets to the underlying myocardium (failure of delamination); (2) anterior and apical rotational displacement of the functional annulus (septal > posterior > anterior leaflet); (3) dilation of the “atrialized” portion of the right ventricle with variable degrees of hypertrophy and thinning of the wall; (4) redundancy, fenestrations, and tethering of the anterior leaflet; (5) dilation of the right atrioventricular junction (the true tricuspid annulus); and (6) variable ventricular myocardial dysfunction. These anatomical and functional abnormalities cause important tricuspid regurgitation, which results in right atrial and right ventricular dilation and atrial and ventricular arrhythmias. Numerous techniques of repair have been described since the first report of Hunter and Lillehei.2Hunter S.W. Lillehei W. Ebstein's malformation of the tricuspid valve: study of a case together with suggestion of a new form of surgical therapy.Dis Chest. 1958; 33: 297-304Crossref PubMed Scopus (64) Google Scholar This is not surprising, because each heart with Ebstein's anomaly is different, and there is infinite variability that can occur with all of the above-mentioned characteristics. The cone reconstruction as described by Dr. da Silva and coworkers3da Silva J.P. Baumgratz J.F. da Fonseca L. et al.The cone reconstruction of the tricuspid valve in Ebstein's anomaly The operation: early and midterm results.J Thorac Cardiovasc Surg. 2007; 133: 215-223Abstract Full Text Full Text PDF PubMed Scopus (175) Google Scholar is different than previous valvuloplasty techniques in that it is closest to an “anatomic repair.” The end result of the cone reconstruction includes 360° of tricuspid leaflet tissue surrounding the right atrioventricular junction. This allows leaflet tissue to coapt with leaflet tissue, similar to what occurs with normal tricuspid valve anatomy. In addition, the reconstructed tricuspid valve is reattached at the true tricuspid valve annulus (atrioventricular junction) so the hinge point of the valve is now in a normal anatomical location. Thinned, transparent atrialized right ventricle is plicated so any areas of right ventricular dyskinesis are eliminated. Redundant right atrium is excised so the size of the right atrium is closer to normal. With the exception of some persistent right ventricular dilation in the early postoperative period, the cone reconstruction restores the appearance of normal tricuspid valve anatomy and function more than any previously described technique. Because this technique can be applied to the wide variety of anatomical variations encountered with Ebstein's anomaly, we have adopted this repair technique when approaching patients with this malformation. Indications for operation have included symptoms, deteriorating exercise capacity, New York Heart Association functional class III, IV heart failure, cyanosis (oxygen saturation <90%), paradoxical embolism, progressive cardiomegaly on chest X-ray (computed tomographic ratio >0.6), progressive right ventricular enlargement on echocardiography, and onset or progression of atrial of ventricular arrhythmias. Observation has been recommended for asymptomatic patients with low normal exercise tolerance, no right-to-left shunting, and only mild cardiomegaly. With the introduction of the cone repair and its excellent early to mid-term results,3da Silva J.P. Baumgratz J.F. da Fonseca L. et al.The cone reconstruction of the tricuspid valve in Ebstein's anomaly The operation: early and midterm results.J Thorac Cardiovasc Surg. 2007; 133: 215-223Abstract Full Text Full Text PDF PubMed Scopus (175) Google Scholar consideration to earlier operative intervention may be given because this procedure can be performed with low risk and provides a near anatomic repair. Relative contraindications to the cone reconstruction include older age (>50 years), moderate pulmonary hypertension, significant left ventricular dysfunction (ejection fraction ≤30%), complete failure of delamination of septal and inferior leaflets with poor delamination of the anterior leaflet (ie, <50% delamination of the anterior leaflet), severe right ventricular enlargement, and severe dilation of the right atrioventricular junction (true tricuspid annulus).