Single-ventricle patients with interrupted inferior vena cava usually undergo staged Fontan surgery, starting with total cavopulmonary shunt (Kawashima operation). Months or years later, the hepatic veins get connected into the pulmonary circulation preventing the development or allowing for resolution of pulmonary arteriovenous malformations,^{Reference Montesa, Karamlou, Ratnayaka, Pophal, Ryan and Nigro1} also eliminating desaturation originating from veno-venous collaterals. In Kawashima patients, almost always completion Fontan is established by the standard lateral or extracardiac tunnel.^{Reference Burstein, Mavroudis, Puchalski, Stewart, Blanco and Jacobs2}

The direct hepatic veins-to-azygos/hemiazygos vein connection offers optimised streaming for hepatic venous blood completely mixing with systemic venous return. This approach had only been described in a few cases focusing on feasibility.^{Reference Amodeo, Di Carlo, Grigioni, De Santis and Di Donato3–Reference Lopez, van den Heuvel, Pieper, Waterbolk and Ebels5} We presented long-term functional and anatomic results of direct hepatic veins-to-hemiazygos vein connection after Kawashima operation.

A 16-year-old girl with left atrial isomerism, single ventricle, d-malposition of the great arteries with pulmonary atresia and interrupted inferior vena cava with hemiazygos continuation to the left superior vena cava is now 13 years after completion Fontan surgery. There was no right-sided superior vena cava. After neonatal palliation with central aortopulmonary shunt, left-sided Kawashima operation was followed at 14 months leaving the hepatic venous return draining via intrapericardial inferior vena cava to right atrium. Almost 2 years later, she exhibited deteriorating physical activity and cyanosis; systemic arterial oxygen saturation decreased to 80%. Cardiac catheterisation/angiography revealed predominantly left-sided pulmonary arteriovenous malformations with desaturated left pulmonary venous blood (84%). It also revealed a close spatial relationship between the intracardiac inferior vena cava and the vena hemiazygos. This was verified by MRI (Fig 1).

Figure 1. Preoperative MRI demonstrating the close proximity of the intrapericardial IVC (hepatic vein drainage black arrow) and hemiazygos vein (white arrowhead).

The operation was performed at the age of 2 years and 11 months through a left postero-lateral thoracotomy without cardiopulmonary bypass; a temporary conduit was interposed from the left-sided atrial appendage to the inferior vena cava before separating it from the right atrium. The intrapericardial inferior vena cava containing the hepatic venous drainage was directly anastomosed with the vena hemiazygos (enlarged with a small Gore-Tex patch). The post-operative course revealed transient intraoperative hepatic congestion, as seen by significant transaminase elevation and ascites, both peaking at 48 hours; at discharge on 15th post-operative day, percutaneous oxygen saturation was 90–95%. Low-dose oral acetylsalicylic acid was prescribed.

Our yearly follow-up protocol as in any Fontan surgery patient included abdominal sonography and liver function parameters, in addition, MRI and cardiac catheterisation early post-operatively and during long-term follow-up at 8 and 12 years.

Three months post-operatively (patient weight 12 kg, height 88 cm), cardiac catheterisation demonstrated a 4.5 mm narrowing at the hepatic vein-to-hemiazygos connection with a mean gradient of 2 mmHg (Fig 2a); Doppler sonography at the anastomosis revealed respiratory flow modulation with a maximum velocity of 0.7 m/s, but there was no signs of hepatic venous congestion and normal liver function tests.

Figure 2. (a) Left: Post-operative schematic diagram showing the hepatic veins-to-hemiazygos connection. Right: Corresponding early post-operative angiography at 3 months revealed a mild narrowing immediately cranial to the hepatic veins-to-hemiazygos anastomosis within the hemiazygos (nearly 4–5mm) (black arrow). (b) Angiography after 12 years shows harmonious growth and unobstructed hepatic venous streaming/blood flow into the hemiazygos vein and farther up.

Thirteen years later (patient weight 33 kg, height 147 cm), the diameter at the hepatic vein-to-hemiazygos connection had increased to 16 mm (Fig 2b) providing unobstructed hepatic venous drainage. Abdominal sonography showed mild heterogeneous echogenicity of the liver, no surface abnormality/nodularity, or splenomegaly. Liver function tests revealed normal synthetic function and only slight elevation of the gamma-glutamyl transpeptidase.