Techniques of Onyx Embolization of Arteriovenous Malformation: 2-Dimensional Operative Video

Advances in endovascular techniques and tools have allowed for treatment of complex arteriovenous malformations (AVMs), which historically may have posed unacceptable risk for open surgical resection. Endovascular treatment may be employed as an adjunct to surgical resection or as definitive therapy. Improvements in embolization materials have made endovascular AVM treatment safer for patients and useful across a variety of lesions. While many techniques are employed for transarterial AVM embolization, the essential tenets apply to all procedures: (1) great care should be taken to cannulate only vessels directly supplying the lesion, and not en passage vessels, prior to injecting embolisate; (2) embolisate should travel into the nidus, but not into the draining veins; (3) embolistate reflux proximal to the microcatheter should be avoided. There are several techniques that accomplish these goals, including the plug and push method, or using a balloon to prevent embolisate reflux. We use controlled injection of liquid Onyx (Medtronic), with increasing pressure over multiple injections pushing the embolisate forward into the AVM. This is repeated in multiple feeding vessels to decrease or eliminate supply to the AVM. Here, we present a 36-yr-old female with a right parietal AVM discovered on workup of headaches. After informed consent was obtained, she underwent preoperative embolization using this technique prior to uncomplicated surgical resection. The video shows the endovascular Onyx embolization of multiple feeding vessels over staged treatment.