Endovascular treatment of intracranial aneurysms with matrix coils: immediate posttreatment results, clinical outcome and follow-up.

INTRODUCTION: Endovascular aneurysm repair with coils has become a safe and effective alternative to surgical clipping. Efforts have been made to create coils that will facilitate aneurysm healing and reduce recurrence. The purpose of this study was to review the safety and durability of our aneurysm treatment using Matrix coils.
METHODS: A total of 39 aneurysms in 38 patients, aged 30 to 77 years, were treated using Matrix coils in 42 procedures. Two procedures were unsuccessful, and 12 were done using only Matrix coils. Aneurysm volume, packing density and percentage length of Matrix coils were calculated. The treatment results, procedural complication rate and clinical outcome were analyzed. Follow-up examinations were available for 34 procedures with a mean follow-up of 4.9 months (maximum 13.5 months).
RESULTS: Angiographic results were similar to those following the use of platinum coils, with complete occlusion or a residual neck in 82.5% of procedures. Six procedures (14%) were complicated with platelet aggregation. Recanalization occurred in 32% of the patients. Nine patients (26%) had major recanalization and were retreated. One patient had a re-bleed 5 months after the treatment resulting in severe disability. The mean packing density of 39.2% in the recanalized aneurysms was similar to that in the nonrecanalized group.
CONCLUSION: In our series, treatment with Matrix coils had a complication rate similar to that reported with platinum coils. However, we had a higher percentage of major recanalizations requiring retreatment. We believe that the absorption of the polymer contributes to the failure of formation of a stable scar within the aneurysm.