Ebstein's malformation. surgical treatment and results

Abstract

Ebstein's malformation can be defined as an anomaly of the tricuspid valve existing in the setting of a right ventricular dysfunction. The technique introduced by Carpentier in 1980 is based on the concept of mobilization of the restrictive anterosuperior leaflet associated with a longitudinal plication of the inlet component of the right ventricle. From January 1980 to December 1999, 142 patients underwent surgery. The mean age was 25 +/- 15 years (1-65). Cyanosis was present in 48% and associated lesions in 64% of the patients. Patients were classified using a functional approach according to the severity of the lesions. Mild displacement of the septal leaflet, along with small size of the atrialized chamber was seen in 5% (referred to as Type A). Massive displacement of the septal leaflet, but with normal motion of the anterosuperior leaflet and an extensive atrialized chamber, was seen in 35% (Type B). In 51%, the mural (inferior) leaflet was absent, the anterosuperior leaflet was severely restricted by muscular trabeculations and very short tendinous cords, and the anterolateral papillary muscle was incorporated in the right ventricular wall. In these patients (Type C), the atrialized chamber was markedly enlarged and had dyskinetic walls. In such cases, the contractility of the distal (functional) right ventricle was also impaired, and some degree of stenosis of the tricuspid valve was present in one-fifth of them. In the most severe cases (8%), the leaflet tissue of the valve was extremely reduced and the right ventricular walls were thin and contracted poorly. This resulted in the so-called tricuspid sack arrangement (Type D). Valve replacement was needed in only 4 cases, with conservative surgery being achieved in 138 patients by means of mobilization of the anterosuperior leaflet and longitudinal plication of the inlet component of the right ventricle. Additional procedures included the use of a prosthetic ring (94 patients) and partial Glenn anastomosis (30 patients). The hospital mortality was 10%, mainly due to acute postoperative right ventricular failure. Actuarial survival was 75% at 10 years. After operation, 94% of the patients were in functional class I or II of the New York Heart Association, and 88% had no or mild tricuspid valve insufficiency as judged by echocardiography. The rate of reoperation was 9% with a mean delay of 3 years. A second repair was performed in 5 patients. Freedom from reoperation was 87% at 10 years. Sinus rhythm was present in 81%, and 8 pacemaker devices were implanted, 5 for surgically induced atrioventricular block, and 3 because of preoperative conduction disturbances. The use of the partial Glenn anastomosis was introduced recently in cases where the right ventricular contractility was severely impaired, and/or tricuspid valve repair was difficult, and/or permanent atrial fibrillation was present. In those patients with high risk, adding partial Glenn anastomosis reduced the operative mortality from 24% to 6%. Another benefit of the cavo-bipulmonary anastomosis was better functional tolerance of mild residual tricuspid valve incompetence. Those patients with the tricuspid sack arrangement had a high rate of reoperation (2/11) and valve replacement (3/11), but suffered no operative deaths. We conclude that tricuspid valvoplasty associated with longitudinal right ventricular plication is superior to valve replacement. The arrangement producing a tricuspid sack is not suitable for conservative surgery. An associated cavo-pulmonary anastomosis decreases the operative mortality in patients at high risk, and seems to preserve right ventricular function.