HELPS Data Support MicroVention's HydroCoil for Cerebral Aneurysms

August 3, 2010—MicroVention, Inc. (Tustin, CA) announced that the final 18-month follow-up data in an international study showed that its HydroCoil embolic system for treating cerebral aneurysms reduced recurrence and retreatment rates and provided improved outcomes in study patients when compared to bare-platinum coils.

According to the company, the 500-patient HELPS (HydroCoil Endovascular Aneurysm Occlusion and Packing Study) was an independently run, prospective, randomized controlled trial. It was the first comparative adjudicated study completed since ISAT (the International Subarachnoid Aneurysm Trial) was presented in 2002, the company stated. The study's chief investigator, Philip White, MD, presented the results at the 7th annual meeting of the Society of Neurointerventional Surgery in Carlsbad, California.

MicroVention summarized the key results of the trial: The HydroCoil had more stable angiographic results with a significant decrease in major remnant/recurrence rates. The primary endpoint of reduction of major aneurysm remnant and recurrence, while neutral, showed a strong trend favoring HydroCoil. There was a very low overall retreatment rate of 3.5% (2.9% HydroCoil vs 3.6% bare platinum). The effect of HydroCoil on major recurrence was superior in ruptured aneurysms and where increased filling by HydroCoil was achieved. There was a reduction of 20% in HydroCoil length used compared to bare platinum. Because of HydroCoil's ability to expand into the aneurysm, there was higher packing density of 68.3% for HydroCoil compared to 24.9% for bare platinum.
 The multicenter, multinational trial showed an overall improvement in coiling aneurysms, with a substantially lower 1-year 3% retreatment rate in HELPS as compared to an 11.3% retreatment rate at 1 year with ISAT. In HELPS, the HydroCoil technology demonstrated more durability for endovascular occlusion of aneurysms compared to bare platinum.

Angiographic results from an independent core lab indicated that there was a statistically significant 8.6% lower aneurysm recurrence with HydroCoil than with bare platinum. Data on effectiveness of the HydroCoil extended to all sizes of aneurysms, including small, medium, and large aneurysms. Aneurysm sizes in the trial ranged from 2 to 25 mm, and 84% of all aneurysms were medium and large in size.

The company noted that the trial protocol did not limit the therapy options, but compared a standard of care that accurately reflects current practice, meaning that physicians could choose to use any manufacturers' platinum coil as well as stents and/or balloons.

The HydroCoil technology is based on a microporous expandable hydrogel. The company states that the HydroCoil is a nonbioactive coil that combines the features of greater aneurysm volume filling with biologically inert scaffolding for natural tissue proliferation. Since the HELPS patient enrollment was completed in 2007, MicroVention says it has continued to make enhancements to its hydrogel line of coils to complement HydroCoil, including the HydroSoft finishing coil that provides hydrogel at the neck of the aneurysm, and the HydroFrame framing coil that provides optimal framing with the benefits of hydrogel.