Endosaccular Treatment of Intracranial Aneurysms Using Matrix Coils: Early Experience and Midterm Follow-Up

Background and Purpose— The authors report their experience using Matrix coils in the treatment of cerebral aneurysms. Methods— The outcomes of 72 consecutive patients (76 aneurysms) who underwent coiling using Matrix coils at our institution were retrospectively analyzed. Results— Seventy-four aneurysms in 70 patients were coiled using Matrix coils (ranging 3% to 100% by coil length; mean 68.8%). Two patients underwent regular platinum coil embolization after failed Matrix coil placement. Thirty-two (42%) ruptured aneurysms were acutely treated. In 46 aneurysms, Matrix composed >50% of coil length. Complete aneurysm occlusion was obtained in 13 aneurysms (17.6%), neck remnant in 30 (40.5%), and dome filling in 31 (41.9%). Procedural morbidity and mortality rates were 1.4% and 1.4%, respectively. Angiographic follow-up was obtained in 63.5% (47 of 74 aneurysms; average 12.2 months; range 0 to 34). In these 47 angiographically followed aneurysms, the overall recanalization rate was 57.4%. In aneurysms with >50% Matrix coils, 76.1% had angiographic follow-up (35 of 46), and in this group, the overall recanalization rate was 54.3% (19 of 35): 25% (1 of 4) for very small (<5 mm); 33% (4 of 12) for small-size (<10 mm)/small-neck (<4 mm); and 63% (5 of 8) for small-size/wide-neck (≥4 mm). A total of 82% (9 of 11) recanalization occurred in large aneurysms (≥10 to 25 mm). Ten aneurysms (21.3%; 10 of 47) underwent retreatment. Clinical follow-up was obtained in 61 (86%) patients (average 15 months; range 1 to 37): 87% of patients were Glasgow Outcome Scale 4 or 5. Conclusion— The use of Matrix coils resulted in worse recanalization rates than that reported for Guglielmi detachable bare platinum coils.