Endovascular Management of Acquired Hepatic Arterial–Portal Venous Malformations

Purpose: Arteriovenous malformations (AVMs) are typically congenital in origin, but acquired types, such as dural arteriovenous fistula (AVF), have been described. This study aimed to describe the diagnosis and endovascular treatment of acquired hepatic arterial–portal venous (HA-PV) malformations. Materials and Methods: A retrospective review of suspected acquired HA-PV malformations from 9/2011 to 2/2018 was performed. Eight patients (1M:7F, average age 62) with HA-PV malformations were identified. Four (50%) patients had a history of liver transplant. All HA-PV malformations were Yakes type IIIA (multiple inflow arteries with a single vein outflow and with the nidus located within the vein wall). In all cases, computed tomography angiography/magnetic resonance angiography was unable to distinguish AVMs from AVFs, and a wrong diagnosis was made in each instance. Results: Review of pre-procedural Doppler ultrasounds in all cases demonstrated arterialization of portal vein waveforms. Review of pre-procedural cross-sectional (CT/MR) imaging in all of these cases demonstrates a network of arteries around the portal vein with early portal vein filling in every instance. Attempts to close the shunts via arterial inflow embolization but without venous nidus occlusion were performed and were unsuccessful in five out of eight (62.5%) cases. All curative therapies were via embolization of the outflow vein (segmental or lobar portal vein). Technical success was seen in seven of eight cases (87.5%), while one patient is planned to receive additional nidal vein embolization. Liver function was preserved after treatment without worsening of bilirubin or albumin levels. Conclusion: The diagnosis of an acquired HA-PV malformation can guide curative endovascular treatment by embolization of the portal vein outflow.