Virtual Treatment Planning for Fontan-Palliated Patients: Prediction of Hepatic Blood Flow Distribution

Background: Formation of pulmonary arteriovenous malformations (PAVM) in Fontan-palliated patients is hypothesized to be caused or at least affected by the distribution of hepatic blood (HFD) toward the left and right pulmonary artery. In patients with PAVM and uneven HFD, surgical or interventional treatment facilitating an even HFD is a promising approach to achieve remodeling of PAVM. However, while the pre-interventional hemodynamics can be assessed via angiography or velocity encoded MRI, prediction of the post-intervention hemodynamics is difficult due to the complex and heterogeneous anatomy of Fontan-palliated patients. Here, computer-based approaches might allow outcome prediction of different treatment strategies for a given patient.

Method: The patient-specific anatomy of the total cavopulmonary connection (TCPC) of three Fontan-palliated patients with PAVM was reconstructed using CT or a combination of CT and MRI images. Due to severe cyanosis, these patients were considered for surgery or catheter-based intervention aiming at hepatic blood flow re-routing. First, numerical simulations were performed. Based on the patient-specific anatomy and the pre-interventional hemodynamics, different treatment strategies were identified during heart team meetings including pediatric cardiologists and congenital heart surgeons. The patient-specific models were altered virtually to mimic these treatment strategies. Finally, for each virtual treatment the resulting HFD was calculated via numerical simulations.

Results: Reconstruction of the complex anatomy of the TCPC was possible in all three patients despite presence of metallic stents. To facilitate this, combined approaches using both CT as well as MRI data were required in two patients. For each patient at least one virtual treatment strategy that was considered viable and simultaneously resulted in a more even HFD was identified.

Conclusion: Virtual treatment planning is a promising approach for patients with complex anatomies, such as the TCPC, which do not allow intuitive assessment of the post-operative changes. Especially as treatment strategies vary widely with respect to their respective risk, an objective outcome assessment might help identify the ideal treatment strategy for a specific patient.

Publication History

Article published online:
28 January 2023