Conversion of complex neonatal Ebstein's anomaly into functional tricuspid or pulmonary atresia.

BACKGROUND

Ebstein's anomaly, due to failure of delamination of one or more leaflets of the tricuspid valve (TV), is associated with varying degrees of tricuspid regurgitation (TR) and dysplasia of the right ventricle (RV). Although refinement of tricuspid valvuloplasty and plication techniques have opened the way to a satisfactory outlook for the majority of older children and adults, Ebstein's anomaly presenting at neonatal age, secondary to ineffective forward flow into the pulmonary and systemic circulation, has a reported mortality rate of as high as 75%. In order to improve the dismal outcome in neonatal Ebstein's anomaly, we have strived for early univentricular palliation.

PATIENTS AND METHODS

Univentricular repair was performed in five neonates (median age 5 days; range 2-14 days) with Ebstein's anomaly, ductal dependent pulmonary blood flow, severe TR, absence of forward flow across the pulmonary valve, and small left ventricular (LV) area due to right-to-left bowing of the ventricular septum and ineffective LV loading (median indexed LV area 10.5 cm2/m2). In addition, two neonates had moderate pulmonary regurgitation (PR), one with additional pulmonary stenosis. In all patients, the indexed area of the combined right atrium and atrialized RV was greater than that of the combined functional RV, left atrium, and left ventricle (median 22.0 and 20.8 cm2/m2, respectively). The median preoperative systemic oxygen tension was 35 mmHg and the median pH 7.28. Repair consisted of TV closure with a pericardial patch (with the coronary sinus draining into the RV) (n = 3) or, in the presence of PR, resection of the dysplastic TV and division and oversewing of the main pulmonary artery (n = 2), as well as excision of the atrial septum, resection of redundant right atrial wall, and construction of an aortopulmonary shunt (n = 5).

RESULTS

The median indexed LV area increased from 10.5 to 18.8 cm2/m2 as a result of more effective loading of the left ventricle. There was no intraoperative or late mortality. The patients were extubated at a median of 7 days postoperatively. At discharge, the median systemic oxygen tension was 46 mmHg. In all five patients, at 6, 7, 10, 12 and 16 weeks of age, a bidirectional cavopulmonary anastomosis has been constructed.

CONCLUSIONS

In neonates with Ebstein's anomaly and ductal dependent pulmonary blood flow, rational palliation consists of the surgical creation of tricuspid atresia or, in the additional presence of PR or pulmonary stenosis, the creation of pulmonary atresia. These procedures may result in effective LV decompression and more effective volume loading of the left ventricle with increase of systemic output and improved clinical outcome.