Three-dimensional echocardiographic evaluation of the Fontan conduit for thrombus

Total caval pulmonary connection (Fontan circuit) is the final common pathway for the palliation of single ventricle congenital heart disease. Flow within the Fontan circuit results in an environment that is prone to thrombus formation putting the patient at risk for pulmonary and/or systemic embolus. To prevent these problems, patients are placed on antithrombotic therapy and periodically evaluated for thrombus within the conduit. Two-dimensional (2D) echocardiography, although commonly used to evaluate these patients, has been shown to have limited ability in accurately identifying thrombi within the Fontan conduit. The diagnosis of intracardiac thrombi has been augmented by three-dimensional (3D) echocardiography and the patients in this series were evaluated with 3D imaging (3D transthoracic echocardiography and/or 3D transesophageal echocardiography) to determine if thrombi could be detected or excluded within the Fontan conduit. To the author's knowledge, this constitutes the first case series describing the use of 3D echocardiography to evaluate the Fontan conduit for thrombus.

The four patients described in this case series underwent 3D echocardiography to evaluate the Fontan conduit for a suspected or potential thrombus.

The Fontan conduit was imaged and thrombi were felt to be documented or excluded in all four patients with 3D echocardiography.

Three-dimensional echocardiography may enhance the ability to detect or exclude thrombi within the Fontan conduit. Further studies are needed to determine if this will prove to be an effective and reliable technique in evaluating the Fontan conduit for thrombus.