Multicenter registry of liquid embolic treatment of cerebral aneurysms

The Cerebral Aneurysm Multicenter European Onyx trial was the first multicenter prospective case series using liquid embolization for cerebral aneurysms. It suggested a possible decreased risk for recanalization of smaller aneurysms compared with coil embolization. After publication of that trial, the Onyx HD embolic agent, injection devices, and treatment protocols have all been updated and improved to increase efficacy and decrease adverse events. We present the results from a multicenter registry of liquid embolization treatments using the current method and materials. We hypothesize that the evolution of this technique will result in lower complication and recanalization rates when compared with earlier series.

Surgeons performing liquid embolization submitted data about consecutive patients and procedures. The data provided were used to determine what characteristics were associated with durable occlusion and recanalization.

One hundred thirteen patients at 25 medical centers throughout the United States underwent liquid embolization. Of these, 110 had follow-up data of at least 6 months. Seventeen patients (15%) experienced a complication and 4 (3.5%) experienced procedure-related ischemic stroke or death. Nine patients (8.1%) had aneurysm recanalization and 5 (4.5%) required retreatment. All retreatments were accomplished with further liquid embolization and were stable at the last follow-up angiogram available. Those with durable occlusion had smaller aneurysm size (mean, 10 mm vs. 17 mm) (P = 0.03) and were de novo (P = 0.02).

Recent advances in liquid embolization have led to decreased recanalization and complications. Liquid embolization is more likely to achieve a durable result in smaller aneurysms that have not been previously treated.