Technical Considerations of Transvenous Biopsies in Patients with Fontan-Associated Liver Disease

1. Discuss pathophysiology and indications for transvenous liver biopsies in patients who have undergone Fontan procedures. 
2. Identify the different types of Fontan and associated anatomy for pre-procedural planning.  

3. List technical and intraprocedural considerations specific to the Fontan patient population undergoing transvenous biopsy and pressure measurements.

4. Highlight techniques via case-based approaches to the potentially challenging anatomy of Fontan patients during transvenous liver biopsy procedures.  

Background: Patients with history of Fontan surgery for congenital cardiac disease are at risk for Fontan-associated liver disease (FALD) and are frequently evaluated with transvenous liver biopsy and pressure measurements.  Technical challenges can present due to the post-Fontan anatomy and concerns about traversing the shunt. Both transfemoral and transjugular approaches for this patient population have been described {1}. 

This educational exhibit will discuss both patient factors and procedural considerations via a pictoral case-based approach in hopes of educating interventional radiologists with limited experience performing this procedure in this specific patient population. 

Clinical Findings/Procedure Details:

Patients who have undergone Fontan surgery are typically monitored for FALD and are referred to IR for transvenous biopsies and pressure measurements which may be done at the same time as cardiac catheterization to evaluate the heart. Technical considerations specific to the post-Fontan patient include access type given that these patients often have a history of central lines which may result in thrombosis or stenosis of the jugular veins or concerns about traversing the Fontan shunt depending on the shunt type. Additionally, the use of heparinization during the procedure can be considered to reduce the risk of stroke in those with fenestrated grafts, but the risks of bleeding should also be weighed in.  Another consideration is which pressures to obtain and from where as this is crucial to ensure all necessary diagnostic information is obtained.  Obtaining a diagnostic tissue sample is tantamount and can be challenging in pediatric patients via the transvenous route due to patient size.  In addition, the hepatic veins may be capacious due to underlying pathophysiology and effects of the Fontan which can make it difficult to obtain sufficient cores. 

Conclusion and/or Teaching Points:

Understanding of post-Fontan anatomy, indications, and possible technical challenges for transvenous liver biopsy are important to successfully and safely perform.