Abstract
Embolization of collateral veins is often treated with rigid coils (Gianturco and interlocking detachable coils type). However, when dealing with tortuous and dilated collateral veins, there is a high risk for technical failure and coil migration due to inflexibility of the coils. To safely and successfully solve this problem, Guglielmi detachable coils (GDC) can be used for embolization. Their flexibility allows for easy navigation in tortuous veins, low risk of unintended coil release or coil migration, and safe deployment. A 12-year-old girl with a single ventricle had severe cyanosis and a low exercise tolerance 5 years after Fontan procedure. The symptoms were caused by a tortuous and dilated collateral from the left phrenic vein into the left pulmonary vein, forming a right-to-left shunt. The collateral, which had a large diameter and high flow, and therefore a high risk of coil migration, was successfully embolized with 8 GDC. There were no complications such as coil migration or cerebral infarction. Transcatheter embolization increased her systemic oxygen saturation from 81%-84% to 94%-95%, and increased her ability to exercise. The embolization procedure using flexible GDC was low risk compared with other rigid coil embolization techniques when performing embolization of tortuous and dilated collateral veins.