Biatrial Drainage of a Right-Sided Superior Vena Cava

Abstract

We report a case of chronic hypoxemia in a 62-year-old woman as a result of biatrial drainage of a right-sided superior vena cava. Radionuclide ventilation and perfusion imaging revealed significant increased radiotracer activity in the kidneys, bowel, and thyroid gland suggesting a right-to-left shunt which was confirmed by contrast enhanced CT of the chest. An anatomically correct right-sided SVC drained through two channels, the larger of which emptied into the roof of the left atrium and a smaller atretic portion feeding the right atrium. We were able to find only nine case reports of this rare anomaly in the English literature. All prior cases demonstrated partial anomalous pulmonary venous return which was also demonstrated to be present in this case with the use of cardiac MRI. According to our literature search, this is one of the few cases to be diagnosed with cardiac MRI.

A Review of the Surgical Management of Anomalous Connection of the Right Superior Caval Vein to the Morphologically Left Atrium and Biatrial Drainage of Right Superior Caval Vein

“…In most instances, however, the SVC was anastomosed to the RAA, the approach known as Warden’s procedure. 8,9 –57,97 This procedure, of course, is an adjunct in repair of the sinus venosus defect when the high placement of the anomalously draining pulmonary veins excludes the option of intra-atrial baffling. 97 For the great majority of patients in whom the right SVC drains to the LA, Warden’s procedure again seems to be the most intuitive, reproducible, and reasonable operation, restoring normal anatomy with an excellent outcome.…”

“…In most cases in which the right SVC drains exclusively to the LA or else exhibits biatrial drainage, saline contrast echocardiography alone gives a clue to the diagnosis. 15,16,20,21,[25][26][27][28][29][30][33][34][35][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57]67,92 In cases where difficulty remains in establishing the diagnosis, cardiac catheterization and angiography are recommended to delineate the anatomic details, including the presence of associated major congenital cardiac lesions, if any. 8,9,14,15,22,25,26,31,48 Magnetic resonance imaging, radionuclide angiography, and computed tomographic angiography are other imaging modalities that may provide an accurate description of the underlying anatomy.…”

“…6 -59 It is seen concomitantly with intracardiac anomalies such as atrial or ventricular septal defects, single atrium, tetralogy of Fallot, transposition of the great arteries, functionally univentricular heart, and Eisenmenger complex. 6 …”

“…Moderate left ventricular enlargement and left ventricular hypertrophy have been noted in some patients. 13,14 ,16,50 ,60 The differential diagnoses of a patient with central cyanosis, in the absence of clinically detectable abnormalities of the cardiovascular system, indicate congenital pulmonary arteriovenous malformation, pulmonary artery to LA communication, partially or totally anomalous systemic venous connection to LA, methemoglobinemia, hemoglobinopathies, pulmonary vascular obstructive disease, and Eisenmenger syndrome. 40,61 -63…”

“…Diagnosis is usually made by saline contrast echocardiography, radionuclide angiography, magnetic resonance imaging, computed tomographic angiography, conventional angiocardiography, or during placement of central venous catheter. 45 ,64,65 Saline contrast echocardiography is very useful in the differential diagnosis. Contrast visualization of the LA, left ventricle, and aorta without opacification of the right ventricle with injections into veins of both hands suggests either drainage of the right SVC to the LA or persistence of the left SVC with unroofing of the coronary sinus.…”