Uncommon cause of late onset anasarca after cardiac surgery

Abstract

A 10-year-old girl presented with a history of having loose stools and generalised swelling for a 1-month period. She had complex congenital cyanotic heart disease-double outlet right ventricle with anatomy unsuitable for two-ventricle repair. She had undergone Fontan surgery 3 years previously. Fontan completion was staged after pulmonary artery (PA) banding and bidirectional Glenn surgery. Her laboratory parameters showed hypoproteinemia with hypocalcaemia (serum protein 3.4 gm/dL, serum albumin 1.3 gm/dL, serum calcium 5.6 mg/dL). The patient's clinical condition was highly suggestive of a particular syndrome and she was started on treatment for that condition. Her echocardiogram showed significant haemodynamic findings (figure 1). She was referred for cardiac catheterisation and a percutaneous intervention was performed ( figure 2A, B). Following the intervention, she improved dramatically with subsidence of symptoms and signs within 3 days. QUESTIONWhat is the significant unexpected haemodynamic finding identified in this patient's echocardiographic image (figure 1 Image challenge ANSWER This girl is suffering from protein losing enteropathy (PLE) due to a failing Fontan circuit. This four chamber echocardiographic view with anterior tilt shows antegrade flow through the PA which had previously been banded. Such flow is detrimental in Fontan physiology and can have serious haemodynamic consequences.1 2 Antegrade flow may increase PA pressures and lead to increased resistance in the Fontan circulation, which in turn may increase resistance in the mesenteric circulation. This may contribute to the development of PLE. On cardiac catheterisation the patient had a high mean PA pressure (17 mm Hg). Therefore, option 3 is the correct answer.The patient underwent device (Amplatzer duct occluder) closure of the RVOT through a Glenn shunt ( figure 2A, B). Understanding the pathophysiology may be useful in the management of PLE in Fontan physiology (figure 3). 3A large VSD is part of the primary condition, and the ASD, if flowing right to left, may simply reflect the elevated pressure in the system (so options 1 and 2 are not correct). There is no left ventricular outflow obstruction (so option 4 is not correct).