Retrieval of a Fractured Marathon Microcatheter Entrapped in Onyx Using a Novel Stentriever-Assisted Technique

Endovascular embolization using Onyx has been a major advancement in the treatment of cerebrovascular malformations. Microcatheter entrapment in Onyx is a procedural complication which can pose a thromboembolic risk to patients. There have been 4 retrieval techniques for intact microcatheters entrapped in Onyx previously described in the literature, which are summarized in this report. We present the first case using a novel stentriever-assisted technique to successfully and safely retrieve a fractured microcatheter entrapped in Onyx.

An adult patient with a Cognard IIa + b dural arteriovenous fistula (dAVF) underwent Onyx embolization. The microcatheter became entrapped and fractured while initially attempting removal. A stentriever was used off label to capture the fractured microcatheter and then a larger caliber microcatheter was railroaded over it. Retrieval of the fractured microcatheter by the stentriever was then facilitated by counter traction on the Onyx cast using the larger microcatheter.

This novel stentriever-assisted technique is a safe and effective rescue maneuver for retrieving a fractured microcatheter trapped in Onyx during embolization of dAVF. There is a need for further research and development of novel devices for retrieval of entrapped microcatheters.