Purpose We describe our experience using detachable tip microcatheters in the embolization of brain arteriovenous malformations, pial arteriovenous fistulas and vein of Galen malformations. We discuss the safety and efficacy using the detachable tip microcatheter.

Methods During a period 9 month from March 2013 through March 2014, 16 pediatric patients in 21 procedures with 39 total injections were selected for treatment with a detachable tip under an FDA compassionate use exemption, and were admitted to our department for treatment of their brain AVM using a liquid embolic agent and a detachable tip microcatheter. The ages of the patients ranged from 3 months to 18 years old.

Results Of the 39 total injections done, in 13 Onyx 18 or Onyx 34 was used. In those, the Catheter tip detached in one case (1/13) (7.5%). In the remaining 26 catheterizations out of the total 39, n-BCA was used for embolization. In those Catheter tip detached in eleven cases (11/26) (42%). There were no cases of premature microcatheter detachment during normal vessel navigation.

Discussion The navigability of the Apollo™ microcatheter is comparable or better to other available over the wire microcatheters. The injection of Onyx or concentrated n-BCA is well controlled and allow reflux in a controlled fashion. The withdrawal is done in a less traumatic controlled fashion with graduated pressure under fluoroscopic guidance. We believe this to result in less chance of catheter entrapment, vessel rupture and haemorrhage.

Conclusion A detachable tip microcatheter offers an advance in the safety and effectiveness of Onyx or nBCA embolization. It permits a true circumferential occlusion, and may further permit filling a larger amount of angioarchitecture. The catheter retrieval becomes more controlled and less traumatic. Our initial experience is encouraging and more experience is needed to categorically ascertain its safety and efficacy.

Disclosures S. Paramasivam: None. D. Altschul: None. J. Fifi: None. S. Ortega Gutiarrez: None. A. Berenstein: None.