Radiopaque Shape Memory Polymers for Neurovascular Embolotherapy Applications

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Radiopaque Shape Memory Polymers for Neurovascular Embolotherapy Applications Project Summary / Abstract This Phase I project involves a major improvement in neurovascular embolotherapy. Aneurysms contribute significantly to annual mortality: an estimated 6.5 million people in the US (~1 in 50) have an unruptured brain aneurysm, with an annual rupture rate of about 8 to 10 in 100,000 people (about 30,000 annually in the US), with fatality in 50% of the rupture cases and an incidence of permanent neurological deficit in 66% of the surviving cases, and nearly 500,000 deaths worldwide annually. The major minimally invasive surgical intervention involves the use of metal-based embolic coils to fill aneurysms. However, metal-based coils impart major artifacts in MRI and CT imaging, and also impart a biohazard heating risk in MRI imaging, complicating critical follow-up post-surgical examinations. Radiopaque shape-memory polymers (SMPs) developed at EndoShape, Inc. were incorporated as coils in the multi-coil MedusaTM first-generation peripheral vascular embolotherapy device. The MedusaTM device, deployed using a large 0.074” catheter, had the required fluoroscopic visibility during deployment because of the multiple radiopaque polymer coils traversing and emerging from the catheter simultaneously as deployed. Leveraging a decision by the FDA in 2006 to re-classify embolic coils as class II devices, the 510(k) clearance of the MedusaTM multi-coil device for peripheral vascular interventions was achieved in 2014, and opened a pathway to 510(k) clearance of next-generation neurovascular devices with radiopaque SMP coils. The radiopaque SMPs used in the MedusaTM device were not sufficiently radiopaque for single-coil devices in the smaller coil wire diameter range that is required for neurovascular applications. Now a new radiopaque monomer, used in combination with more efficient crosslinkers that impart required mechanical properties at lower incorporation, allowing higher incorporation levels of the radiopaque monomer, has enabled required radiopacity to be achieved in a wire diameter range that is estimated to be 0.010”-0.021” while retaining required performance properties, biodurability and biocompatibility. EndoShape is on the verge of being able to apply radiopaque SMPs to neurovascular devices with the advantages first provided to surgeons by the use of the MedusaTM device. The materials-based advantages of EndoShape SMPs obviate the disadvantages of metal coils, including in addition to the improvements in the safety and efficacy of MRI and CT imaging in post-surgical examinations and a reduction in surgical expense due to the lower-cost materials comprising EndoShape polymer-based coils. From 2020-2025 the total embolotherapy device market is forecasted to increase from $1.26 to $1.64 billion (+30.2%), and the market that EndoShape can address with its radiopaque polymer based SMP coils is expected to increase from $0.89 to $1.17 billion (+31.5%); highlighting the impact EndoShape polymer-based coils are capable of exerting in medical device markets and in improved embolotherapy patient care.