Single-ventricle patients with interrupted inferior vena cava (IVC) can develop pulmonary arterio-venous malformations due to abnormal hepatic flow distribution (HFD). However, preoperatively determining the hepatic baffle design that optimizes HFD is far from trivial. In this study, we combine virtual surgery and numerical simulations to identify potential surgical strategies for patients with interrupted IVC.

Five patients with interrupted IVC and severe PAVMs were enrolled. Their in vivo anatomies were reconstructed from MRI (n=4) and CT (n=1), and alternate virtual-surgery options (intra/extra-cardiac, Y-grafts, hepato-to-azygous and azygous-to-hepatic shunts) were generated for each. HFD was assessed for all options using a fully validated computational flow solver.

For patients with a single superior vena cava (SVC, n=3), intra/extra-cardiac connections proved dangerous, as even a small left or right offset led to a highly preferential HFD to the associated lung. Best results were obtained with either a Y-graft spanning the Kawashima to split the flow, or hepato-to-azygous shunts to promote mixing. For patients with bilateral SVCs (n=2), results depended on the balance between the left and right superior inflows. When those were equal, connecting the hepatic baffle between the SVCs performed well, but other options should be pursued otherwise.

This study demonstrates how virtual-surgery environments can benefit the clinical community, especially for rare and complex cases such as single-ventricle patients with interrupted IVC. Furthermore, the sensitivity of the optimal baffle design to the superior inflows underscores the need to characterize both pre-operative anatomy and flows to identify the best suited option.