Mass General Hospital
APRIL 2013

Atrial Baffle Stenosis: A Late Complication after Mustard Repair for d-TGA
Ali D. Karaosmanoglu, MD; Suhny Abbara, MD; Sanjeev Francis, MD; Doreen DeFaria Yeh, MD; and Godtfred Holmvang, MD

  Clinical History
A 37 year old male with a history of d-transposition of the great arteries and Mustard atrial switch operation as an infant presented with abdominal distension and facial swelling.

Cardiac MRI and CT were performed for evaluation of the atrial baffle and biventricular function.

Cardiac MRI demonstrated significant stenosis at the superior and inferior limbs of the baffle (figure 1). The atrial baffle path for pulmonary vein flow was widely patent. The systemic right ventricle was hypertrophied with low normal systolic function (RVEF=45%).

Cardiac CT demonstrated an anomalous left circumflex artery arising from a common trunk with the right coronary artery from the posterior sinus of Valsalva and anteriorly located ascending aorta relative to the main pulmonary artery (figure 2). Ascites and liver cirrhosis due to chronic right atrial hypertension were also visualized.

The patient underwent cardiac catheterization followed by successful angioplasty and stenting of the stenotic segments in the atrial baffle. Post procedure, his neck fullness resolved and ascites markedly improved.

Figure 1A

Figure 1B

Figure 1C

Figure 2

(Click on image to enlarge)

Figure 1(A,B,C): MR images of the atrial baffle. (A) SSFP image of the heart demonstrating superior (curved arrow) and inferior (solid arrow) vena cavae and the baffle obstruction point (arrowhead) (B) Baffle stenosis with a minimal luminal diameter of 4mm (arrow) leading to obstruction of systemic venous return. (C) Volume rendered image showing unobstructed drainage of all five pulmonary veins into the tricuspid inflow region(RU: Right upper pulmonary vein, RM: Right middle pulmonary vein, RL: Right lower pulmonary vein, LU: Left upper pulmonary vein, LL: Left lower pulmonary vein, TV Inflow: Right atrium leading to tricuspid valve) .

Figure 2:
Axial image showing abnormal anterior and rightward location of the ascending aorta relative to the main pulmonary artery. The posterior sinus of Valsalva gives rise to a right coronary artery and left circumflex artery (arrowhead) via a common trunk. Left pulmonary vein drains into the right atrium (arrow). AO: Ascending aorta, MPA: Main pulmonary artery, RA: Right atrium.

D-transposition of the great arteries (d-TGA) refers to the dextroposition of the bulboventricular loop and ventriculoarterial discordance (1). Due to failure of spiral septation of the truncus arteriosus, the great arteries course parallel to each other rather than crossing. The aorta arises from the morphologic right ventricle and the main pulmonary artery from the morphologic left ventricle. Communication between the pulmonary and systemic circuits is necessary for infant survival either via an atrial septal defect, patent ductus arteriosus or ventricular septal defect. Ventricular septal defects are the most common associated anomaly, observed in almost half of the cases. Pulmonary outflow tract obstruction and coarctation of the aorta may also be seen (2).

Atrial septostomy was the original surgical procedure first performed in the 1960s. The atrial switch procedure (Mustard or Senning types) then became the most common surgical treatment. Right ventricular dysfunction, tricuspid regurgitation, atrial arrhythmias and heart block are frequently encountered in the follow-up of these patients. The arterial switch procedure has become the preferred technique to repair d-TGA.It involves the transection and switching of the great arteries with reimplantation of the coronary arteries, thus restoring normal ventriculo-arterial concordance. Baffle leaks and obstruction are common late complications of atrial switch surgery.

Baffle leaks should be considered in patients with stroke or paradoxical embolism and baffle obstruction should be considered in patients with signs and symptoms of systemic venous hypertension. Percutaneous angioplasty or surgery is the main treatment strategy in baffle obstruction.

1. Warnes CA. Transposition of the great arteries. Circulation. 2006;114:2699-2709
2. Hornung TS, Derrick GP, Deanfield JE, Redington AN. Transposition complexes in the adult: a changing perspective. Cardiol Clin. 2002;20:405-420
3. Hornung TS, Benson LN, McLaughlin PR. Catheter interventions in adult patients with congenital heart disease. Curr Cardiol Rep. 2002 Jan;4(1):54-62

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