A novel self-expanding shape memory polymer coil for intracranial aneurysm embolization: 1 year follow-up in Chile

Abstract

BackgroundAneurysm recurrence remains a challenge when coiling cerebral aneurysms. Development of next generation coils has focused on accelerating thrombus maturation and increasing coil packing density. Ultra low density shape memory polymer is a novel embolic material designed for this purpose. The polymer is crimped over a platinum–tungsten coil for catheter delivery and self-expands to a predefined volume on contact with blood.MethodsThis prospective study in humans evaluated aneurysms 5–16 mm (inclusive) in diameter that were indicated for endovascular coil embolization. At least 70% coil volume was required to be shape memory polymer coils. Patients were followed-up according to standard of care for 12 months.ResultsNine patients (89% women, mean age 55.8±11.7 years) were treated with shape memory polymer coils and completed 12 months of follow-up. Aneurysms were all unruptured and were in the ophthalmic segment of the internal carotid artery (n=7), posterior communicating artery, and anterior cerebral artery A1–A2 segment. Aneurysms were a mean of 7.8±2.9 mm in diameter (range 5.2–14.9 mm). The mean packing density based on unexpanded polymer was 17±6%. Packing density based on expanded polymer was 43±13%. At 12 months, no recurrence had occurred, and a Raymond–Roy occlusion classification of 1 (n=5) or 2 (n=4) was observed. No serious adverse events related to the study device occurred over the 12 months after the procedure.ConclusionsShape memory polymer coils were safe and effective in treating intracranial aneurysms over 12 months in this first study in human subjects.

Single Component Polymers, Polymer Blends, and Polymer Composites for Interventional Endovascular Embolization of Intracranial Aneurysms

“…[135] It was found that SMP coils were efficient and safe for the treatment of intracranial aneurysms over 12 months in human studies. [132] Kunkel et al [2] characterized aliphatic urethane-based SMP for determining efficiency as a new material in embolization. The time of shape recovery was lower than 11 s with SMP formulations, being low enough to change shape during the embolization procedure.…”

“…Expanded form possesses great surface area and promotes the formation of thrombus throughout its structure. [132] J. Wang et al [138] developed a biocompatible and highly porous PU SMP material for the fabrication of endovascular devices in the treatment of complex intracranial aneurysms. These researchers claimed that porous PU SMP material and electrical resistance heating trigger mechanism can enhance long-term therapeutic outputs of endovascular intracranial aneurysm therapy.…”

“…[ 22 ] SMP is crimped over a platinum‐tungsten coil for catheter delivery and self‐expands to a predefined volume upon contact with blood ( Figure 11 ). [ 132 ] TrelliX coil is coated by polyurethane (PU) SMP foam, allowing the device to fill 2.5 times more volume than GDCs after activation. Foam expansion could be triggered after aneurysm coiling, supposed to raise packing density and prevent recurrence.…”

“…[ 135 ] It was found that SMP coils were efficient and safe for the treatment of intracranial aneurysms over 12 months in human studies. [ 132 ]…”

“…Expanded form possesses great surface area and promotes the formation of thrombus throughout its structure. [ 132 ] J. Wang et al. [ 138 ] developed a biocompatible and highly porous PU SMP material for the fabrication of endovascular devices in the treatment of complex intracranial aneurysms.…”