title: HydroCoil for Endovascular Aneurysm Occlusion (HEAL) study: 3-6 month angiographic follow-up results.
abstract: OBJECTIVE
  The HydroCoil Embolic System (HES) was developed reduce recurrences of aneurysms relative to platinum coils. This study was conducted to evaluate the recurrence rate of cerebral aneurysms 3-6 months after treatment with HES.
  
  
  METHODS
  We report the results in 135 cerebral aneurysms treated with HES in a prospective multicenter registry. Angiographic results 3-6 months after treatment were evaluated at a core laboratory. Wide variation in HES utilization within the HydroCoil for Endovascular Aneurysm Occlusion (HEAL) registry (HES representing 5% to 100% of the coil length used) allowed for subgroup analysis with regard to percentage length, last coil used, and packing attenuation in small (<10 mm) aneurysms.
  
  
  RESULTS
  The overall recurrence rate was 38 (28.1%) of 135, which included a number of large, giant, and previously recurrent aneurysms. When HES represented > or = 75% of coil length, the recurrence rate was 0 (0%) of 18, whereas with <75% length of HES, the recurrence rate was 16 (23%) of 71 (P = .035). When the final coil deposited was a HES coil, the recurrence rate was 6 (11%) of 53, whereas when the final coil was platinum, the recurrence rate was 10 (29%) of 34 (P = .047). When the packing attenuation was > or = 50%, the recurrence rate was 11 (19%) of 59, whereas for packing attenuation <50%, the recurrence rate was 5 (18%) of 28. The packing attenuation calculations were very error-prone.
  
  
  CONCLUSIONS
  Although the overall recurrence rates for small and large aneurysms in HEAL were no lower than published rates for aneurysms treated with platinum coils, patients treated in HEAL had a reduced recurrence rate when greater than 75% of the coil length used to treat an aneurysm was HES and when the final coil was HES.
authors.affiliation: Department of Radiology, Mayo Clinic, Rochester, MN 55905, USA. cloft.harry@mayo.edu
authors.forename: H J
authors.initials: HJ
authors.lastname: Cloft
mesh_terms: D001672:Biocompatible Materials; D020099:Coated Materials, Biocompatible; D004621:Embolization, Therapeutic / Q000295:instrumentation*; D004867:Equipment Design; D005060:Europe; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging / Q000628:therapy*; D010984:Platinum; D011446:Prospective Studies; D011859:Radiography; D012008:Recurrence; D012042:Registries; D014481:United States
chemical_list: D001672:Biocompatible Materials; D020099:Coated Materials, Biocompatible; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D010984:Platinum