Hepatic Venous Anomalies Complicating Total Cavopulmonary Connection

A female infant was born with a complex type of univentricular heart, heterotaxia, left atrial isomerism, bilateral superior vena cavae (SVC), and interrupted inferior vena cava (IVC) with hemiazygous continuation into the left SVC. At 9 months of age, she underwent palliative correction consisting of a Damus-Kaye-Stansel anastomosis ^1–3 and a modified Blalock-Taussig shunt. In early childhood, she underwent a 2nd operation in which bilateral, bidirectional Glenn anastomoses were constructed. At that time, the anomalous hepato-cardiac veins were left intact, connected to the right-sided atrium. The child did well for several months but then became increasingly cyanotic. Bilateral intrapulmonary arteriovenous fistulae were evident at cardiac catheterization.

An operation was to be performed with use of a polytetrafluoroethylene extracardiac conduit (GORE-TEX®; WL Gore & Associates; Flagstaff, Ariz), avoiding cardioplegic arrest in light of the patient's somewhat compromised ventricular function. At surgery, however, it was found that the right and left hepatic veins drained separately into the right-sided atrium. The left vein was smaller and was connected to the atrium adjacent to the coronary sinus. We decided to divert the hepatic venous return from the larger right-sided hepatic vein only, leaving the left hepatic vein connected to the atrium (Fig. 1). During the early postoperative period, the patient's oxygen saturation remained low. Color-flow Doppler echocardiography revealed unidirectional, low-velocity, continuous flow through both of the Glenn anastomoses and the pulmonary arteries. At cardiac catheterization, the extracardiac conduit and the hepatic veins showed evidence of bidirectional flow, with opacification of the common atrium via right-to-left shunting of blood from the pulmonary vascular bed through large intrahepatic collateral vessels (Fig. 2). The patient underwent reoperation to occlude the left hepatic vein with an adjustable snare (Fig. 3). The resulting elimination of the right-to-left shunt led to marked improvement in the arterial oxygen saturation. There were no changes in hepatic function.

Fig. 1 Diversion of hepatic venous return from the right hepatic vein; the left hepatic vein remains connected to the atrium.

Fig. 2 Cardiac catheterization shows right-to-left shunting of blood from the pulmonary vascular bed into the atrium through large intrahepatic collateral vessels.

Fig. 3 Occlusion of the left hepatic vein with an adjustable snare, which results in elimination of the right-to-left shunt.

Comment

Patients with complex single-ventricle anatomy and atrial isomerism often present with anomalies of the pulmonary and systemic veins, such as persistence of the left SVC, and interrupted IVC with azygos or hemiazygos continuation of the IVC into the right or left SVC. ^4,5 In these situations, anatomic correction usually entails cavopulmonary connection by means of bilateral, bidirectional cavopulmonary anastomoses as described by Kawashima and co-authors, ⁶ leaving the anomalous hepatic veins intact, draining directly into the atrium. However, when the hepatic venous return does not drain into the pulmonary circulation, intrapulmonary arteriovenous fistulae frequently develop, leading to a progressive decrease in systemic oxygen saturation and severe cyanosis. ⁷ As a consequence, incorporation of the hepatic venous return with the systemic venous return has been advocated, not only to eliminate the residual right-to-left shunt and volume overload of the single ventricle, but also to prevent, or induce regression of, intrapulmonary arteriovenous fistulae. ⁸

Diversion of hepatic blood flow into the pulmonary circulation can be accomplished by several strategies, one of which is to interpose an extracardiac conduit between the hepatic veins and the right pulmonary artery, as previously described ⁹ (Fig. 1). However, construction of an extracardiac conduit can be technically cumbersome in patients whose hepatic veins drain separately into the atrium, particularly when one of them drains adjacent to the coronary sinus. In the presence of this anatomic variant, one of the available surgical alternatives consists of connection of only one of the hepatic veins to the conduit, with the 2nd one remaining connected to the atrium (Fig. 1).