Presentation
History of double inlet left ventricle, status post several cardiac corrective operations, including TGA switch. Presented with chest pain, mild hypoxia - suspected pulmonary embolism.
Patient Data
Surgical clips and coils projected onto the area of great vessels takeoff from the heart - status post cardiac corrective operations.
Fontan conduit abutting right heart border.
Normal width of heart, mediastinum, and thoracic aorta.
Prominent right pulmonary artery.
Lungs clear.
Single ventricle supplied by both atria, (i.e. double inlet LV). Status post arterial switch of Jatene, PA banding and septostomy, Glenn shunt, and extracardiac Fontan procedure without fenestration.
Pulmonary emboli cannot effectively be ruled out because the blood in the right pulmonary arteries has yet to mix homogeneously with the contrast material and the left pulmonary arteries have not even begun opacifying.
Iatrogenic pectus excavatum. The sternebrae are cleaved down the middle due to previous sternotomies.
Case Discussion
A month after birth, a complex cyanotic cardiac defect was diagnosed: double inlet left ventricle (DILV) with AV discordance, left AV (i.e. tricuspid) valve atresia, side-by-side transposition of the great arteries (d-TGA). DILV denotes a single ventricle that receives blood from both atria.
The patient underwent the following procedures at infancy:
- pulmonary artery banding (PAB): a constrictive band is placed around the pulmonary trunk. This is a palliative procedure in left-to-right shunting with pulmonary overcirculation before definitive treatment, to prevent pulmonary hypertension and improve systemic pressure and cardiac output. Early intracardiac repair procedures have mostly obviated the need for this procedure. However, in this complex case that included TGA, PAB also readied the left ventricle for the arterial switch procedure (see below)
- atrial septostomy: the infant did not have a large-enough interatrial septum for the oxygen-poor blood to mix with the oxygen-rich blood, so it was enlarged before commencing with the arterial switch
- arterial switch: transection of the great arteries above the levels of their sinuses and translocation to their proper anatomical positions. During the procedure, the coronary arteries are lifted together with a nubbin of aortic sinus wall for each and implanted into the neo-aorta
- bidirectional Glenn operation - this was the second stage of preparation for the Fontan procedure (see below), after PAB: the superior vena cava (SVC) was disconnected from the right atrium (RA) at their junction and its end was sewn end-to-side to the right pulmonary artery (RPA) and the bifurcation of the main pulmonary arteries is disconnected from the pulmonary outflow tract
- extracardiac Fontan procedure without fenestration: this is a variation on the classic Fontan procedure, whereby a synthetic tube outside the heart connects the inferior vena cava (IVC) to the inferior aspect of the right pulmonary artery. 'Fenestration' means the creation of a connection between the conduit and the right atrium for lowering venous systemic pressure in the IVC via the lower-pressure atrium, which was deemed unnecessary here.
- patent ductus arteriosus (PDA) clipping: this procedure was not mentioned in any accessible document but is obvious on both the x-ray and CT exams
For some time, he was treated with sildenafil citrate and bosentan for pulmonary hypertension. The patient was tested for hypercoagulability after an episode of upper limb deep vein thrombosis (DVT). He was found to be homozygous for MTHFR [homocysteine level 9.8 μmol/L (normal)], and treated with coumadin, aspirin, and iron.