A 10-year-old female with heterotaxy-asplenia and complex CHD developed pulmonary arteriovenous malformations with associated cyanosis after Fontan completion. She underwent orthotopic heart transplantation, but her pulmonary arteriovenous malformations persisted with progressive worsening cyanosis. Elective transcatheter left pulmonary artery embolisation was performed 2 years post-transplant, which successfully normalised her oxygen saturation without a significant increase in pulmonary artery pressure.

Pulmonary arteriovenous malformations are a frequent cause of progressive cyanosis after construction of a cavopulmonary anastomosis. Their formation complicates the management of children with single ventricle physiology after a bidirectional Glenn shunt or the Kawashima procedure. The key role of the liver in this phenomenon is suggested by the observation that providing modifications of the Fontan procedure which permit hepatic venous effluent to reach the pulmonary arterial circulation limit further development of the malformations. In addition, it is known that patients with end-stage hepatic failure develop pulmonary arteriovenous malformations that diminish after liver transplantation. We have begun purification of a factor derived from hepatocyte-conditioned media that is inhibitory for the proliferation of cultured endothelial cells. This substance is heat sensitive, and binds avidly to a copper-containing chromatography column. These clinical observations, and this preliminary experimental work, support the concept that hepatic-derived angiogenic factors may play a role in the development of pulmonary arteriovenous malformations after construction of cavopulmonary anastomoses.

A homogeneous opacity of the right upper lobe was found radiographically in a 15-month-old male child during investigation of an upper respiratory tract infection. Based on computerized tomography, the diagnosis was made of a solid tumor of the lung. At thoracotomy, dilated serpentine vessels were found on the surface of the right upper lobe, and the diagnosis of a large arteriovenous malformation was considered. Use of enhanced computed tomography without contrast and failure to note a reduced arterial oxygen saturation were two diagnostic pitfalls. The diagnosis of an arteriovenous malformation was confirmed by pulmonary angiography, and a right upper lobectomy was successfully performed.

There have been several modifications of the Fontan procedure, which has been used for palliation of the functionally univentricular circulation since its conception in the early 1970s. The development of intrahepatic veno-venous fistulas, pulmonary arteriovenous fistulas, and communications from the hepatic vein to the pulmonary venous atrium, are some of the complications encountered by patients with cavo-pulmonary communications. We describe transcatheter creation of an atriopulmonary communication, with simultaneous implantation of a stent, as a method of reducing or preventing pulmonary arteriovenous fistulas and associated right-to-left shunting in this setting. The intervention has been undertaken in two patients following a Hemi-Fontan procedure, itself created subsequent to a Glenn anastomosis. The combination of these procedures creates communicating atriopulmonary and cavopulmonary circulations.