2020 Scientific Sessions

Title

Closure of a Mustard baffle leak with an aortic stent graft – an innovative way to treat an intracardiac shunt

Introduction

Patients who underwent the Mustard procedure for Transposition of the Great Arteries (D-TGA) have on average 80% survival 30 years after surgery. Some complications related to the surgery, such as baffle obstruction, baffle leak, atrial arrhythmias or heart failure require cardiac reintervention. We present an interesting case of intracardiac shunt in a patient 46 years after undergoing the Mustard procedure for D-TGA

Clinical Case

46-year-old man who underwent Mustard procedure for D-TGA presented to hospital with atrial flutter and hypoxia. His systemic ventricle (morphologic right ventricle) was severely dilated with reduced function (Ejection fraction less than 20%) and a bubble study during echocardiography suggested a baffle leak. Patient was not a transplant candidate and underwent atrial flutter ablation during admission. Cardiac MRI demonstrated 2 leaks in the SVC limb of the baffle (20 mm and 9 mm) and 1 leak in the IVC limb (minimal) causing shunting of deoxygenated blood into the systemic circulation. There was also stenosis of the distal portion of the SVC limb. It was felt that the patient’s anatomy was not amenable to closure with a covered stent, ASD closure device or vascular plug. The patient subsequently underwent closure of the baffle leak in the SVC limb of the baffle with a Medtronic Endurant II, 25x70 mm aortic extension graft. He had immediate resolution of his hypoxia and dyspnea. Repeat echocardiography completed 5 days post-procedure showed improvement in his systemic ventricular function (ejection fraction 40%).

Discussion

Many adult congenital heart disease patients who received intervention during childhood experience complications later in life that require re-intervention. As these patients often have complicated anatomy which is high-risk for re-intervention, novel methods of intervening on these patients in a minimally invasive fashion are important to help reduce long-term morbidity and improve quality of life. Our patient was deemed to be high risk and was not a candidate for surgical re-intervention for his intracardiac shunt. Traditional methods of percutaneous intervention with an Amplatzer ASD closure device, Vascular plug or existing covered stents were not felt to be amenable due to the size and shape of the baffle leak. As the patient’s native right atrium formed part of the SVC baffle, there was also size mismatch between parts of the baffle conduit in the area of the major leak (15 mm in SVC, 26 mm in atrial portion of baffle, and 10 mm in distal portion of baffle towards left atrium). This required the use of a covered stent with a large diameter. Therefore, an aortic stent graft was chosen, which allowed for adequate seal of the defect in the widest diameter. This innovative use of an aortic stent graft to close a baffle leak may be a novel way of treating patients with unusual or high-risk anatomy.