This is a clinical trial/study for patients diagnosed with brain arteriovenous malformation (AVM). An AVM is an abnormal connection between the arteries and veins of the brain. Patients considered for this trial are 21 years and younger with AVM suitable for embolization treatment (a procedure used to block the abnormal connection between the arteries and veins of the brain) with Onyx Liquid Embolic System (Onyx LES) or TruFill n-Butyl Cyanoacrylate (n-BCA) Liquid Embolic System (both are liquid substances used in the embolization procedure to block the abnormal connection).

-Why is this study being done?

The purpose of this study is to evaluate the safety of the Apollo Embolization Delivery Micro Catheter device (device that looks like a long thin hallow tube) when used in Pediatric patients with vascular malformations.

The Apollo Onyx Delivery Micro Catheter device is manufactured by Micro Therapeutics, Inc. d/b/a ev3 Neurovascular. Apollo Onyx™ Delivery Micro Catheter device is not approved for use in the U.S, although it is widely used and approved for use in Europe (CE0297).

This clinical study is sponsored by Dr. Alejandro Berenstein of St.Luke's-Roosevelt Hospital, New York who is also the principal Investigator of the study. Total duration of study is up to 30 months with approximately an 18 months enrollment period. Patients follow up period is up to 12 months upon enrollment.

Inclusion Criteria:

• The subject or subject's legally authorized representative has signed and dated an informed Consent Form.
• Subject's age is ≤ 21 years.
• The subject has a confirmed diagnosis of brain arteriovenous malformation in the cerebral cortex, cerebellum or dura mater that is indicated for endovascular embolization with Onyx™ LES or TruFill n-Butyl Cyanoacrylate (n-BCA) Liquid Embolic Systems and where the use of Apollo Embolization Delivery Micro Catheter may or may not be indicated for surgical resection.
• The subject is clinically and neurologically stable for a minimum of 48 hours prior to embolization.
• The subject has a life expectancy of at least 1 year with the exception of new born babies with Vein of Galen malformation with cardiopulmonary failure where no other treatment option remains.
• The subject agrees to and is capable of completing all study required procedures

Exclusion Criteria:

• Female who is pregnant or lactating.
• Current participation in another investigational drug or device study.
• Subject has a brain tumor or other malignancy