Clinical and angiographic outcome of intracranial aneurysms treated with Matrix detachable coils in Chinese patients

Abstract

Background

Aneurysm recurrence is an innate problem in endovascular treatment of aneurysms with coils. A coated coil system named Matrix (Boston Scientific Neurovascular, Fremont, CA), covered with a bioabsorbable polymeric material (polyglycolide/lactide copolymer [PGLA]), was developed to accelerate intraaneurysmal clot organization and fibrosis. The purpose of this study was to evaluate the efficacy and safety of the Matrix detachable coils in patients with intracranial aneurysms and aneurysmal recurrence rate.

Methods

In a regional neurosurgical center in Hong Kong, data of patients undergoing endovascular embolization of intracranial aneurysm was collected. In a 20-month period, 42 patients with 44 aneurysms were treated by endovascular embolization using matrix coils alone or mixed with bare platinum coils. Thirty-four patients presented with ruptured aneurysms, and 8 patients presented with unruptured aneurysms.

Results

Twenty-five patients (60%) had 6-month follow-up DSA, and 10 patients (24%) had 18-month follow-up DSA. Seven aneurysm recurrences were identified, amounting to 16% for all aneurysms and 14% for ruptured aneurysms. Four patients were treated by repeated embolization, and 2 patients were treated by microsurgical clipping. Two adverse events due to thromboembolism were noted. One 78-year-old lady with poor-grade subarachnoid hemorrhage treated by partial embolization died from rebleed at day 4. Another patient with partial embolization and spontaneous thrombosis of dorsal wall ICA aneurysm died at 2 months with aneurysm recanalization with rerupture. Twenty-six patients achieved favorable outcome (GOS score 4 or 5) at last follow-up. The aneurysm recurrence rate using bare platinum coils of the same center was 11% and 7% for all aneurysms and ruptured aneurysms, respectively.

Conclusion

Matrix coil embolization was safe, but there was no reduction in aneurysm recurrence using matrix coils alone or mixed with GDCs, compared with GDCs alone.

Introduction

Endovascular coil embolization using GDC has become an accepted therapeutic option for the treatment of intracranial aneurysms [7]. The most important limitation of coil embolization is the possibility of aneurysm recanalization, which results in aneurysm recurrence [8], [14], [16]. Platinum coils are biologically inert and produce a limited and delayed inflammatory response. Acceleration of intraaneurysmal clot organization and fibrosis using bioabsorbable polymeric material was proposed to be a solution in preventing aneurysm recanalization after endovascular treatment. Matrix detachable coils (Boston Scientific Neurovascular) were developed with the above mission in mind. These platinum coils are covered with a bioabsorbable copolymer (90% polyglycolide and 10% PGLA). In swine models, Matrix was shown to accelerate aneurysm fibrosis and neointima formation without parent artery stenosis [9], [10], [11], [12]. The current study aimed to investigate whether the above results would translate into durability of aneurysmal occlusion, and hence, it would reduce the incidence of aneurysm recanalization after embolization.