Traditionally, surgical cure rates for small, superficial arteriovenous malformations (AVMs) in non-eloquent regions of the brain approaches 100%. However, as AVMs become larger and deeper or encroach upon eloquent areas of the brain, surgical cure rates rapidly decrease and complications increase. Thus, non-invasive techniques such as radiotherapy and embolization have been investigated for these scenarios. 

     It was the objective of this study to demonstrate that using a novel technique, cure rates for Onyx embolization could approach those of open surgery.

     Twelve patients underwent AVM embolization using Onyx with intention to cure in a single session.

     Two microcatheters were placed in tandem within the feeding vessel. The proximal microcatheter was used to form a well-controlled plug around the distal treatment catheter. This mitigates the concern for backflow of Onyx and entrapment of the catheter, allowing for faster push rates and greater injection volumes.

     Using this technique, it was possible to achieve a cure rate of over 80% in a single treatment using an average injection of 8.8 mL of Onyx. Of the cases in which an angiographic cure was not achieved, the AVMs were reduced in size by an average of 85%. Of those patients who have returned for follow-up, only 14.3% demonstrated evidence of recurrence at 6 months.

     This was a small retrospective series.

     By forming a controlled short segment plug near the tip of the treatment catheter, it is possible to push higher volumes of Onyx at greater injection rates and thereby achieve an angiographic cure in a single treatment session.

     New embolization techniques should be evaluated as part of multi-modal management of AVMs.