Case report

“A” now aged 33, with a non-trisomic unbalanced atrioventricular septal defect, had a total repair at the age of 29 months. At the time, the “Anderson’s cleft” was sutured to reduce the moderate left-sided atrioventricular valve regurgitation. The large atrial defect and a smaller ventricular component of the atrioventricular septal defect were closed by a two-patch technique. A small right ventricle was enlarged by extensive resection of trabeculations following which the right-sided atrioventricular valve measured 19 mm, only 1 mm smaller than that expected at her age thereby allowing a two pump repair. A single stitch was placed between the edge of the superior common leaflet and the Dacron patch to reduce the mild-to-moderate right-sided atrioventricular valve regurgitation. Off bypass, the mean right atrial pressure was 10 mmHg when compared to 9 mmHg mean left atrial pressure. Despite that she developed increasing systemic venous congestion. At catheteriation during the age of 5, her right atrial pressure was 28 mmHg. Further surgery was undertaken. Her superior caval vein was connected to her right pulmonary artery. In addition, a 1 mm valvotomy on either side of the single commissure of her right-sided atrioventricular valve enlarged it to 13 mm with a gradient of 14 mmHg with dysplastic regurgitation. The right ventricle remained small and heavily trabeculated and the right atrium very dilated. The superior caval vein pressure dropped to 13–14 mmHg post-bypass when compared to 6–8 mmHg in the left atrium.

Considerable clinical improvement was subsequently observed, but with ongoing evidence of right atrioventricular valve stenosis (Fig 1). At the age of 24, she started having atrial arrhythmias – atrial flutter/atrial tachycardia/fibrillation. Each episode required a transoesophageal echocardiogram followed by direct current cardioversion, maintenance of anti-arrhythmic therapy, and ongoing anticoagulation. Three electrophysiology studies were undertaken with multiple flutter pathways ablated. Throughout, her right atrium remained very dilated with a mean Doppler gradient of 12–14 mmHg across the atrioventricular valve.

Figure 1.

Stenotic right-sided atrioventricular valve. RAVV = right-sided atrioventricular valve.

Further surgery was not considered as a good option, neither was balloon dilating the valve that was previously tried with rheumatic tricuspid stenosis. ^{Reference Asmarats, Taramasso and Rodés-Cabau1} The decision was made to endovascularly rehabilitate the right atrioventricular valve connection. At the age of 29, she underwent an uncomplicated procedure with balloon interrogation of that valve, ensuring that the right coronary artery was not compressed and with pre-stenting the stenotic connection. A Melody valve was deployed to 20 mm (Fig 2). That halved the mean Doppler gradient across the valve to 6–7 mmHg. Two further episodes of atrial flutter occurred 3 and 5 months later despite anti-arrhythmic medication. She had further dilation of the Melody valve to 22 mm 8 months after its insertion, with a reduction in the gradient down to 5 mmHg but with the development of mild incompetence, which gradually improved with time.

Figure 2.

Colour flow through the Melody valve at the right atrioventricular valve site. RAVV = right-sided atrioventricular valve.

Four years later, she has remained well and fully employed. She has a mean Doppler gradient of 6 mmHg across the valve during inspiration dropping to 4 mmHg during expiration with minimal evidence on colour Doppler of incompetence. The “lumen” of the valve measured 13 mm as estimated on cross-sectional imaging. Her liver subjected to prolonged venous congestion has improved considerably when last checked a year ago with a fall in the liver stiffness from a high of 30 KPA to 7.2KPA by FibroScan. Her liver is described as smooth on ultrasound, not suggestive of cirrhosis. There has been a halving of her slightly elevated liver enzymes. With the onset of symptomatic bradycardia, she recently had a dual-chamber pacemaker inserted with epicardial leads for atrial pacing. As the right atrium remains enlarged (see supplementary Figure 2), it was thought prudent to maintain her on Apixaban.