Double atrioventricular valve replacement using Melody™ transcatheter valves in an infant with unbalanced atrioventricular septal defect: a case report

Abstract

Background: To the best of our knowledge, this is the first report of a successful one-stage double atrioventricular valve (AVV) replacement using two Melody™ transcatheter valves in an infant.

Case summary: We report a successful case of double AVV replacement with Melody™ transcatheter valves in a 9-month-old infant with a right ventricular dominant atrioventricular septal defect (AVSD). The boy initially presented with borderline sized left-sided heart structures, congenital left AVV stenosis, ventricular displacement of the right AVV with high-grade insufficiency and moderate valvar pulmonary stenosis. Double AVV replacement was performed 2 months after an unsuccessful attempt to repair the defect with persisting left AVV stenosis, underfilling of the small left ventricle and high-grade right AVV, and pulmonary valve regurgitation, resulting in low cardiac output. During double Melody™ AVV replacement, the right ventricular outflow tract was replaced with a pulmonary homograft. The boy was discharged on post-operative Day 28 and presented with competent valves, no ventricular outflow tract obstruction and no paravalvular leak at 11 months of follow-up.

Discussion: The presented innovative approach allowed for biventricular correction of an unbalanced AVSD with unfavourable anatomy for standard techniques. The heart team should decide individualized, after careful assessment of cardiac anatomy and function, if the benefits of replacement of AVVs with Melody™ transcatheter valves may outweigh the benefits of univentricular palliation in case of unbalanced AVSD.

Keywords: Bioprosthetic valve replacement; Biventricular repair; Case report; Infant; Melody; Transcatheter valve; Unbalanced AVSD.

Figure 1

(A) Transthoracic echocardiogram in the subcostal four-chamber view demonstrating morphology before first surgery. LA, left atrium; LAVV, left atrioventricular valve; LV, left ventricle; RA, right atrium; RAVV, right atrioventricular valve; RV, right ventricle. (B) Transthoracic echocardiogram in the four-chamber view and corresponding colour image demonstrating atrioventricular valve inflow, dysplastic and stenotic left atrioventricular valve (white arrow), and ventricularly displaced right atrioventricular valve (black arrow). (C) Transthoracic echocardiogram in the four-chamber view and corresponding colour image demonstrating severe both-sided atrioventricular valve regurgitation. (D) Transthoracic echocardiogram in the subcostal view and corresponding colour image demonstrating severe pulmonary valve stenosis (black arrow). MPA, main pulmonary artery; others as before.

Figure 2

(A) Transthoracic echocardiogram in the apical four-chamber view and corresponding colour image demonstrating atrioventricular valve stenosis after first surgery. (B) Transthoracic echocardiogram in the apical four-chamber view and corresponding colour image demonstrating atrioventricular valve regurgitation after first surgery. (C) Transthoracic echocardiogram in parasternal short-axis view and corresponding colour image demonstrating pulmonary valve (black arrow) with severe regurgitation. (D) Transthoracic echocardiogram in parasternal long-axis view demonstrating underfilled left ventricle and long narrow left ventricular outflow tract.

Figure 3

(A) Chest radiograph demonstrating left-sided (white arrow) and right-sided Melody™ valve with bended distal rows of the stent struts (black arrow) in projection on the atrioventricular valve. (B) Transthoracic echocardiogram in atypical parasternal long-axis view demonstrating the left-sided (white arrow) and right-sided Melody™ valve (black arrow) in atrioventricular valve position.

Figure 4

(A) Transthoracic echocardiogram in the apical four-chamber view demonstrating the left (white arrow) and right Melody™ valve (black arrow) in atrioventricular valve position. LLPV, left lower pulmonary vein; LUPV, left upper pulmonary vein; others as before. (B) Corresponding colour image demonstrating good flow across the Melody™ valves and no hindered left-sided pulmonary venous drainage.

Figure 5

(A) Transthoracic echocardiogram in parasternal long-axis view demonstrating left ventricular outflow tract without circumscribed obstruction and reflection of the right-sided Melody™ valve in atrioventricular position (black arrow). (B) Corresponding colour image demonstrating good flow across the left ventricular outflow tract.