Congenitally interrupted inferior vena cava without other features of the heterotaxy syndrome: report of five cases and characterization of a rare entity.

Congenital interruption of the inferior vena cava (IVC) due to absence of its hepatic segment is usually found in patients with polysplenia. The occurrence without other features of the heterotaxy syndrome is rare, and the frequency of associated additional vascular and cardiac anomalies in these patients is not well known. We reviewed the literature and present 5 of our own patients to characterize this entity. All but 1 of the 67 known cases had visceroatrial situs solitus. There was 1 patient with interruption of the IVC in complete situs inversus. The interrupted IVC typically continued via the azygos system into the superior vena cava, but there were 4 cases without a direct connection between the infrahepatic IVC and the azygos system. Additional venous abnormalities or cardiac malformations were present in 47.8% and 31.4%, respectively. In contrast to the classical heterotaxy syndrome, heart defects with interrupted IVC and normal situs did not involve inversion of cardiac segments. The diagnosis can readily be made by echocardiography or magnetic resonance imaging. Failure to recognize this anomaly can result in various problems during invasive medical or surgical procedures. In our own patients, interventional procedures failed, necessitating an operation in all 5 cases. Careful analysis of systemic venous drainage should be performed in all patients prior to cardiac catheterization, pacemaker implantation, or surgery, even if the visceroatrial situs is normal.