GREAT-a randomized controlled trial comparing HydroSoft/HydroFrame and bare platinum coils for endovascular aneurysm treatment: procedural safety and core-lab-assessedangiographic results

Neuroradiology. 2016 Aug;58(8):777-86. doi: 10.1007/s00234-016-1693-y. Epub 2016 Apr 30.


Introduction: Hybrid hydrogel-platinum coils (HydroCoil) have proven effective for endovascular aneurysm treatment. To overcome technical limitations (coil stiffness, time restriction for placement), a second generation of softer hydrogel coils has been brought to clinical practice (HydroSoft, HydroFrame). We report on procedural safety and core-lab-assessed angiographic results from an open-label multicenter randomized controlled trial.

Methods: Web-based randomization occurred in 15 medical centers in France and seven in Germany between coil embolization with second-generation hydrogel coils and treatment with any bare platinum coil. Assist devices could be used as clinically required. Primary endpoint is a composite outcome including major aneurysm recurrence and poor clinical outcome at 18 months follow-up.

Results: Five hundred thirteen patients were randomized (hydrogel n = 256, bare platinum n = 257). Twenty patients were excluded for missing informed consent and nine patients for treatment related criteria. Four hundred eighty-four patients were analyzed as randomized (hydrogel n = 243, bare platinum n = 241). Two hundred eight had ruptured aneurysms (43 %). Prespecified procedural complications occurred in 58 subjects (hydrogel n = 28, bare platinum n = 30, p = 0.77). The 14-day mortality rate was 2.1 % in both arms of the study. The median calculated packing densities for aneurysms assigned to hydrogel and bare platinum were 39 and 31 % respectively (p < 0.001). No statistically significant differences were found between arms in the post procedural angiographic occlusion rate (p = 0.8).

Conclusion: Second-generation hydrogel coils can be used in a wide spectrum of aneurysms with a risk profile equivalent to bare platinum. Packing density was significantly higher in aneurysms treated with hydrogel coils.

Trial registration: , DRKS00003132.

Keywords: Hydrogel coils; Intracranial aneurysm; Randomized controlled trial.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Blood Vessel Prosthesis*
  • Cerebral Angiography / methods
  • Endovascular Procedures / instrumentation*
  • Equipment Failure Analysis
  • Female
  • France
  • Germany
  • Humans
  • Hydrogels / chemistry*
  • Intracranial Aneurysm / diagnostic imaging*
  • Intracranial Aneurysm / therapy*
  • Male
  • Middle Aged
  • Platinum / chemistry*
  • Prosthesis Design
  • Treatment Outcome


  • Hydrogels
  • Platinum