Study Comparing Onyx and TRUFILL in Brain Arteriovenous Malformations (AVMs)
Study Comparing Onyx and TRUFILL in Brain Arteriovenous Malformations (AVMs)
Test whether AVMs treated with Onyx is equivalent to treatment with n-BCA. Success is defined
 as an AVM size reduction greater than 50%
Recent advances in the endovascular treatment of arteriovenous malformations (AVMs) have
 increased the number of patients with brain AVMs for whom embolization therapy may be
 appropriate. The permanency of obliterated nidi and occurrence of procedural complications
 are thought to be at least partially influenced by the characteristics of the material used,
 with liquid agents more likely to reach and occlude the AVM nidus compared to particulate
 embolic agents.

 The only liquid embolic agent approved in the U.S. for the presurgical embolization of AVMs
 is TRUFILL®. TRUFILL n-butyl cyanoacrylate (n-BCA) is a liquid adhesive that polymerizes into
 a solid material upon contact with blood fluids or tissue, via an anionic mechanism. TRUFILL
 Ethiodized Oil is mixed into the n-BCA monomer as a radiopaque polymerizing retardant.
 TRUFILL Tantalum Powder may also be added for radiopacity. The TRUFILL n-BCA Liquid Embolic
 System received U.S. FDA premarket approval on September 25, 2000 (P990040) for use in the
 embolization of cerebral AVMs, when presurgical devascularization is desired.

 Onyx™ is a non-adhesive liquid embolic agent comprised of ethylene vinyl alcohol (EVOH)
 copolymer dissolved in dimethyl sulfoxide (DMSO), and of micronized tantalum powder. Onyx
 precipitates into a solid on contact with blood fluids, due to rapid diffusion of the DMSO
 solvent. The Onyx Liquid Embolic System received the European "CE mark" in July 1999, and has
 been available outside of the U.S. since September 1999 for use in the embolization of AVMs.

 The purpose of this randomized-controlled study is to obtain prospective clinical data on the
 performance of Onyx (investigational device) and TRUFILL (control device) in the presurgical
 embolization of brain AVMs. Device safety will be assessed by comparing overall and
 device-related morbidity and mortality. The primary efficacy endpoint is the angiographic
 reduction in AVM size (volume) achieved. The objective is to demonstrate that Onyx is no
 worse than TRUFILL within a specified clinical tolerance. Study results will be used to
 support a premarket approval application for Onyx in the presurgical embolization of brain
 AVMs.
Inclusion Criteria:

 -  The patient or patient's guardian understands and will sign the informed consent for
 the procedure

 -  The patient has a confirmed diagnosis of a brain AVM in the cerebral cortex,
 cerebellum or dura mater as visualized by angiography or cross sectional imaging.

 -  The brain AVM has a Spetzler-Martin grade of I, II, III, or IV. If the brain AVM has a
 Spetzler-Martin grade of I or II, the anticipated benefit of embolization for surgical
 resection is greater than the risk of the embolization procedure (e.g., patient
 stability).

 -  The patient is a candidate for surgical resection of the AVM post embolization.

 -  The patient is clinically and neurologically stable, for a minimum of 24 hours prior
 to embolization.

 -  The patient agrees to have, and is capable of completing, all study-related exams and
 procedures.

 -  Patient of any age.

 Exclusion Criteria:

 -  The patient is pregnant.

 -  The patient has a brain AVM with high flow arteriovenous fistulae that the
 investigator has determined to be unsuitable for embolization.

 -  The brain AVM has a Spetzler-Martin grade of V.

 -  The patient is participating in another research study involving another
 investigational device, procedure or drug.

 -  The brain AVM has been previously treated with another embolization agent