title: Initial clinical experience with matrix detachable coils for the treatment of intracranial aneurysms.
abstract: OBJECTIVE
  The Matrix detachable coil is a new bioactive, bioabsorbable coil used in the endovascular embolization of intracranial aneurysms. It has a platinum core covered with a bioactive, bioabsorbable polymer (polyglycolic acid/lactide). The authors report on their initial midterm clinical experience with the first-generation Matrix detachable coil.
  
  
  METHODS
  One hundred twelve patients harboring 118 aneurysms were treated using Matrix coils. Forty-nine aneurysms (41.5%) were associated with acute subarachnoid hemorrhage (SAH). Twenty-four lesions (49%) were harbored by patients with Hunt and Hess Grade I, 11 (23.4%) by patients with Grade II, eight (16.3%) by those with Grade III, and six (12.2%) by those with Grade IV. Four aneurysms (3.4%) were harbored by patients who had presented with nonacute SAH. Sixty-five aneurysms (55%) were unruptured. Fifty-seven lesions (48.3%) were small with a small neck, 29 (24.6%) were small with a wide neck, 30 (25.4%) were large, and two (1.7%) were giant. All patients were followed up to obtain angiography and clinical outcome data. Technical complications occurred in six patients: two thromboembolic complications and four aneurysm perforations. Of these six patients, the status of two deteriorated because of aneurysm perforation and another two because of thrombus formation (morbidity 3.6%). There were five deaths--one due to rerupture after embolization. Angiography follow-up studies of 87 aneurysms were obtained. Seventy aneurysms demonstrated progressive occlusion or a stable neck (80.5%), and 17 had some degree of recanalization (19.5%). The aneurysms originally diagnosed as a neck remnant showed a 15% rate of recanalization.
  
  
  CONCLUSIONS
  Matrix coils can be delivered into aneurysms with technical complications similar to those encountered using GDCs. Midterm anatomical outcomes to date have shown moderate improvement in the recanalization rate when compared with those realized using the GDC system. Because of the increased friction associated with the first-generation Matrix coil, the packing density in most aneurysms was less than that achieved with GDCs. Prolonged angiography follow-up evaluations are needed to document long-term efficacy.
authors.affiliation: Division of Interventional Neuroradiology, David Geffen School of Medicine, University of California, Los Angeles, California 90095-1721, USA. ymurayama@jikei.ac.jp
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Murayama
authors.forename: Fernando
authors.initials: F
authors.lastname: Viñuela
authors.forename: Akira
authors.initials: A
authors.lastname: Ishii
authors.forename: Yih-Lin
authors.initials: YL
authors.lastname: Nien
authors.forename: Ichiro
authors.initials: I
authors.lastname: Yuki
authors.forename: Gary
authors.initials: G
authors.lastname: Duckwiler
authors.forename: Reza
authors.initials: R
authors.lastname: Jahan
mesh_terms: D020341:Absorbable Implants; D000328:Adult; D017542:Aneurysm, Ruptured / Q000000981:diagnostic imaging / Q000401:mortality / Q000628:therapy*; D002533:Cerebral Angiography; D020099:Coated Materials, Biocompatible; D004868:Equipment Failure; D004869:Equipment Safety; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging / Q000401:mortality / Q000628:therapy*; D019344:Lactic Acid; D008297:Male; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers; D012008:Recurrence; D012042:Registries; D013345:Subarachnoid Hemorrhage / Q000000981:diagnostic imaging / Q000401:mortality / Q000628:therapy*; D013673:Technology Assessment, Biomedical; D016896:Treatment Outcome
chemical_list: D020099:Coated Materials, Biocompatible; D011108:Polymers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid