HEPATIC VENOUS-BLOOD AND THE DEVELOPMENT OF PULMONARY ARTERIOVENOUS-MALFORMATIONS IN CONGENITAL HEART-DISEASE

Background Pulmonary arteriovenous malformations (PAVMs) are a known c omplication after some types of cavopulmonary anastomoses (CVPAs). The ir cause is unknown, but they may be related to the absence of pulsati le flow or the presence or absence of circulating factors. These PAVMs are diffuse and are presumed to be progressive and irreversible. Meth ods and Results All patients with congenital heart disease (CHD) seen at Children's Hospital, Boston, Mass, between 1970 and 1993 were revie wed. We report on the 10 patients With CHD who were found to have deve loped PAVMs, as diagnosed by cardiac catheterization. Diagnoses includ ed heterotaxy syndrome/polysplenia, with interrupted inferior vena cav a and hepatic veins draining to the right atrium (n=6); heterotaxy/asp lenia (n=1); corrected transposition with pulmonary stenosis (n=1); an d biliary atresia and associated CHD (n=2). PAVMs were diagnosed 0.1 t o 7.0 years (median, 3.5 years) after creation of a CVPA that resulted in exclusion of hepatic venous flow from one or both lungs in 8 of th e, 10 patients; the remaining 2 patients had normal drainage of hepati c veins to the lungs but had biliary atresia. In all, the common anato mic feature was the exclusion of normal hepatic venous return from the affected pulmonary arterial circulation. All patients with interrupte d inferior vena cava, azygous continuation to the superior vena cava, and hepatic veins draining to the right atrium (polysplenia syndrome) were reviewed to determine the incidence of PAVMs in those with CVPA ( ie, hepatic Venous flow excluded from the pulmonary arteries) and with out CVPA. Six of 28 (21%) of those with versus 1 of 56 (1.8%) of those without CVPA developed PAVMs (P=.004). The 1 patient without CVPA who had PAVMs also had biliary atresia. Among patients with CVPA, the pro bability of developing PAVMs was 15% and 28% at 3 and 5 years, respect ively, after CVPA. The histological and angiographic appearances of PA VMs after CVPA are similar to those seen in PAVMs associated with hepa tic cirrhosis. Conclusions We postulate that PAVMs after CVPA are rela ted to the diversion of normal hepatic venous flow from the pulmonary circulation. In this sense, these PAVMs may be analogous to those asso ciated with liver disease, which have been found to resolve after live r transplantation. Redirection of hepatic flow to the pulmonary bed in some patients with CHD and PAVMs may lead to reversibility of the PAV Ms.