Coil embolization of reversed-curve hepatointestinal collaterals in radioembolization: potential solutions for a challenging task.

Depending on the planned catheter position for selective internal radioembolization, coil embolization of hepatic artery branches can be necessary to enable a selective and safe procedure. The anatomy of the hepatic arterial bed has been demonstrated to have a substantial number of anatomic variations, which turns coil embolization into a challenge if the feeder shows a reversed, "hairpin-like" turn immediately after its origin. Hepatointestinal collateral vessels originating from the periphery of the right hepatic artery often present with such a reversed course and can preclude patients from uncomplicated radioembolization if catheterization fails. The purpose of this report is to describe 2 potential solutions for successful coil embolization of reversed-curve hepatointestinal collateral vessels using either a regular 4 French RIM catheter or a novel steerable tip-deflecting microcatheter.