Interventional Radiology

Coil Embolization of Intra-Hepatic Shunts

Normally, all of the blood that come from the intestines flows directly to the liver so the liver is able to process toxins coming from the intestinal tract. Shunts occur when there is a direct communication between the blood coming from the intestines (portal circulation) and the systemic circulation (caudal vena cava). This is a congenital abnormality. Shunts can be classified as extrahepatic (where the communication occurs outside of the liver) or intrahepatic (communication occurs within the liver).

The treatment that provides the best outcome is to correct the shunting vessel. Unfortunately, this is challenging to do in intrahepatic shunts since the surgeon would have to dissect the liver, which has been associated with many complications. Surgical approaches for IHPSSs have been associated with complication rates as high as 77%, perioperative mortality rates as high as 64%. This prompted the need of developing alternative treatment options for these patients. 

A CT scan is necessary prior to the endovascular procedure in order to map the shunting vessel. Then, a separate procedure will be scheduled for the endovascular procedure. This helps to minimize anesthesia time as well as intravenous contrast load. We recommend performing these procedures when patients are somewhere between 4-6 months of age.

Endovascular techniques were developed to close the shunting vessel (i.e. decrease blood flow through the shunting vessel). This technique involves passing guidewires and catheters through the jugular vein (typically) and accessing the shunting vessel. Thrombogenic coils are placed within the shunting vessel to decrease flow. A stent in the caudal vena cava is placed in order to prevent the coils from migrating into the systemic circulation. Portal pressures are measured during the procedure to make sure that the coils are not significantly increasing portal pressures, which could be associated with gastrointestinal side-effects. Patients normally remain in the hospital for 1-2 days after the procedure.