Comparison between second generation HydroSoft coils and bare platinum coils for the treatment of large intracranial aneurysms

Abstract

Background: The development of HydroSoft coils (HSC) aims to reduce the high recurrence and retreatment rates observed in large brain aneurysms by improving primary brain aneurysm filling and thus occlusion efficacy. We compared clinical and angiographic effectiveness of bare platinum coils (BPC) versus second generation HSC for large intracranial aneurysms at our center.

Methods: We included 61 large aneurysms between 2015 and 2018, 29 embolized primarily using HSC and 32 treated with BPC. The aneurysm occlusion rates were assessed after 3 and 12 months with an MRI scan and at 6 moths with a control digital subtraction angiography (DSA) using the Raymond-Roy occlusion classification (RROC). Clinical outcomes were evaluated using the modified ranking scale (mRS).

Results: The observed immediate occlusion rate was slightly better in the BPC group, however, this group had a significant increase of progressive reperfusion at all imaging follow-up. Contrarily, the rate of complete occlusion increased significantly in the HSC group, starting from the 6 and 12-months follow-up. 7 aneurysms (11.4%) were re-treated (15.6% BPC and 6.9% HSC). The 6 and 12-months clinical data showed mRS score 0-1 in 96.7% of patients.

Conclusions: In our single-center experience, the second generation HydroSoft coils were shown to be safe and effective for endovascular treatment of large intracranial aneurysms with encouraging clinical and angiographic results, also for ruptured aneurysms. Even if the validity is limited due to our small cohort size, HSC showed a significantly lower rate of recurrence at mid-term follow-up when compared to BPC.

Keywords: Hydrocoils; Large aneurysms; cerebral aneurysm.

Figure 1.

Unruptured supraclinoid ICA aneurysm treated by SAC with neuroform atlas stent and hydroSoft coils. a) DSA shows the aneurysm at the supraclinoid segment of right internal carotid artery (ICA) (max. width 18 mm); b) Angiographic vision of the Neuroform Atlas stent deployed between the M1-segment of the middle cerebral artery (MCA) and homolateral ICA, covering the aneurysmal neck. A microcatheter is positioned in the aneurysmal sac. c) The final angiogram shows a minimal neck remnant (RROC 2). d) The 3-months follow-up MRI confirms the RROC 2. e) The 6-months DSA control demonstrates complete occlusion of the aneurysmal sac (RROC 1); f) The 12-months MRI follow-up confirms RROC 1.