Regression of severe pulmonary arteriovenous malformations after Fontan revision and “hepatic factor” rerouting

Flow simulations in arbitrarily complex cardiovascular anatomies – An unstructured Cartesian grid approach

“…These malformations are normally prevented by humoral factors released by the liver [36][37][38][39] and carried to the lungs by the IVC. Their presence in the left lung would thus imply that most of the IVC flow is directed to the RPA, while the preferential orientation of the IVC towards the LPA leads one to the opposite conclusion.…”

Imaging and patient-specific simulations for the Fontan surgery: Current methodologies and clinical applications

“…Furthermore, the intrapulmonary shunts lead to a drop in pulmonary vascular resistance, which tends to direct more flow to the diseased lung creating a positive feedback loop of increasing hypoxia. Although the underlying mechanism leading to PAVMs is unknown, studies have shown that liver derived factors present in the hepatic venous blood prevent their formation (Pandurangi, Shah et al 1999; Justino, Benson et al 2001; Shinohara and Yokoyama 2001; Duncan and Desai 2003; Pike, Vricella et al 2004). While it is not known what concentration of this hepatic factor is required for normal lung development, it is clear that an unbalanced hepatic flow distribution to the left and right lungs due to an inadequate design of the IVC-to-PA conduit during the 3 rd stage of the TCPC surgery puts patients at risk for PAVMs.…”

“…While it is not known what concentration of this hepatic factor is required for normal lung development, it is clear that an unbalanced hepatic flow distribution to the left and right lungs due to an inadequate design of the IVC-to-PA conduit during the 3 rd stage of the TCPC surgery puts patients at risk for PAVMs. Clinically, once the extent of PAVMs is such that oxygen saturation is critically low, the only palliative option is to re-operate and re-orient the IVC conduit to achieve a better hepatic flow distribution (Uemura, Yagihara et al 1999; Steinberg, Alfieris et al 2003; Pike, Vricella et al 2004; Wu and Nguyen 2006; AboulHosn, Danon et al 2007). …”

“…Several palliative options have been discussed in the literature(Stamm, Friehs et al 2002; Pike, Vricella et al 2004; AboulHosn, Danon et al 2007), but clearly the wide variety of patient anatomies makes it difficult to design a general “one-size-fits-all” procedure for Fontan patients. In parallel, the complexity and variability of in vivo anatomies pose significant clinical challenges to identify the surgical option for a given patient, i.e.…”

Technical feasibility and intermediate outcomes of using a handcrafted, area-preserving, bifurcated Y-graft modification of the Fontan procedure

“…2,3 Other morbidities such as the formation of pulmonary arteriovenous malformations are related to the distribution of hepatic blood flow. 4 Since the initial, atriopulmonary connection was described, significant modifications have been implemented, most notably the total cavopulmonary connection and its lateral tunnel and extracardiac forms. Computational simulation studies show that by offsetting the anastomotic site of the inferior vena cava (IVC) baffle/conduit into the pulmonary arteries, lower energy loss can be achieved in comparison to the traditional T-shaped junction.…”