Discussion

In 2008, Lopez et al^{Reference McElhinney, Marx and Marshall2} performed the first off-pump hepatic-to-azygos connection via thoracotomy to resolve pulmonary arteriovenous malformations by using a polytetrafluoroethylene vascular prosthesis for the connection. It significantly reduced the complications associated with re-sternotomy and cardiopulmonary bypass compared with the traditional extracardiac conduit technique. McElhinney et al^{Reference Arrigoni, Heuvel and Willems3} argued that a direct hepatic-to-azygos connection might provide more reliable mixing and a bilateral distribution of hepatic venous blood, while avoiding the formation of unilateral pulmonary arteriovenous malformations. A 10-year follow-up study confirmed the approach’s efficacy and safety.^{Reference Lopez, Heuvel and Pieper4}

Prosthetic material is commonly used for making the hepatic-to-azygos connection, such as polytetrafluoroethylene, with consequent lifelong antithrombotic treatment required. Reports have surfaced that favour the pedicled autologous pericardial roll as an ideal option for an extracardiac conduit.^{Reference Adachi, Yagihara and Kagisaki5,Reference Adachi, Ishibashi-Ueda and Yagihara6} In vivo, the conduit has the potential to grow in a parallel manner with somatic development.^{Reference Adachi, Yagihara and Kagisaki5} Immunohistologic examination showed the presence of endothelium and the absence of calcification and fibrosis 9 years after a pedicled autologous pericardium implantation.^{Reference Adachi, Ishibashi-Ueda and Yagihara6} We believe that an isolated autologous pericardium might also be an ideal material. Although the isolated autologous pericardium lacked the growth potential, it might require a shorter period of anticoagulation treatment than what is needed for artificial prosthetic materials.

The timing of the staged palliation remains under dispute. If the hepatic-to-azygos connection was performed simultaneously with the Kawashima procedure, it would be analogous to performing a one-stage Fontan completion.^{Reference Amodeo, Carlo and Grigioni7} To the contrary, to prolong the uncomplicated stage as long as possible, Arrigoni et al^{Reference Arrigoni, Heuvel and Willems3} suggested making the hepatic-to-azygos connection after initial signs of development of pulmonary arteriovenous malformations. However, there have been cases reporting that not all pulmonary arteriovenous malformations can be reversed.^{Reference Setyapranata, Brizard and Konstantinov8} Performing the hepatic-to-azygos connection for the Fontan completion prior to when pulmonary arteriovenous malformations might form seemed to be a reasonable solution.

It was essential to have an operation plan to evaluate the pattern of hepatic vein drainage due to its variability, including isolated drainage through bilateral independent branches and other potential routes. For the branches of the hepatic vein, the surgeons used to make an atrial cuff as a conduit for the hepatic-to-azygos connection. Creating an intra-atrial tunnel was mentioned as well as connecting the branches outside the atrium by prosthetic conduits. Ligating directly has also been reported, especially in cases of reoperation due to the undiagnosed branches.^{Reference Lopez, Heuvel and Pieper4}

We tentatively used the autologous pericardial roll for the hepatic-to-azygos connection because it might require a short period of anticoagulation treatment. Although the short-term evaluation was satisfactory, a long-term follow-up would confirm the prognosis.