INTRAHEPATIC VENOUS COLLATERALS PREVENTING SUCCESSFUL STENT-SUPPORTED COIL EMBOLIZATION OF INTRAHEPATIC SHUNTS IN DOGS

The purpose of the following study was to evaluate stent-supported coil embolization of the hepatic vein in combination with antithrombotic treatment as a method for treatment of intrahepatic shunts, and to describe the complications associated with this procedure. Seven dogs with an intrahepatic shunt were included in a prospective clinical trial. A stepwise procedure was performed. First intervention: transjugular retrograde portography and stent implantation into caudal vena cava; second intervention: hepatic vein embolization combined with an antithrombotic treatment; third intervention in dogs with residual shunting: hepatic vein embolization without antithrombotic treatment. A right shunt was found in one dog and a left shunt in six dogs. Primary intrahepatic venous collaterals were found in one dog and hepatic vein embolization was not performed. Stent implantation into the caudal vena cava was performed in the other six dogs. There was no stent migration or thrombosis. Following the first coil intervention two dogs died due to vessel laceration while removing an oversized or migrated coil. On follow-up the shunt was completely closed in one dog. Secondary intrahepatic venous collaterals developed after the first or second coil intervention in two and one dog, respectively. In conclusion, stent-supported coil embolization of the hepatic vein in combination with an antithrombotic treatment was of limited success because primary or secondary intrahepatic venous collaterals tend to occur.