Early primary Kawashima operation combined with direct hepatic vein-to-azygos vein connection: A new logical approach

Patients with single ventricle, left isomerism, and azygos continuation of the inferior vena cava usually undergo a staged cardiac repair comprising a total bidirectional cavopulmonary anastomosis with the exclusion of the hepatic venous return (Kawashima operation) during childhood followed by a complementary hepatic vein–to–pulmonary artery connection (Fontan completion) 2 to 3 years later. The latter step can effectively counteract the progressive cyanosis resulting from both systemic venous collaterals emptying into the low-pressure hepatic venous compartment and pulmonary arteriovenous malformations related to lack of a putative hepatic or splanchnic factor. However, both the intracardiac and the extracardiac conventional pathways for diverting the hepatic venous return to the pulmonary circulation are highly predisposed toward thrombosis. This is caused by an intrinsic tendency for deep vein thromboses typical in patients with interrupted inferior vena cava, sometimes associated with hypercoagulable state secondary to factor XII deficiency or heterozygous presence of factor V Leiden mutation, and by the relative low flow from the hepatic veins. Focusing on the issue of low flow, we hypothesized that the hepatic venous return (20% of total venous return) should preferably merge with the azygos vein and follow its stream, rather than struggling its way up to the pulmonary arteries against the overwhelming gravitational flow from the superior vena cava (carrying 80% of the total venous return).