Introduction Endovascular treatment of aneurysms with coils is based on the assumption that dense packing leads to intra-aneurysmal flow reduction with subsequent thrombosis and occlusion. Despite significant advances in technology, anatomic results remain suboptimal with residual and recurrent aneurysms being a drawback of the coiling procedure. In this report we describe a novel device for treatment of intracranial aneurysms and report safety, technical feasibility and anatomic outcomes in a canine aneurysm model.

Materials and methods This study tested novel endovascular coils (Medina Medical, Menlo Park, California) consisting of a linear radiopaque mesh that, when deployed, self-expands to a three-dimensional shape that conforms to the aneurysm. Coils were deployed via standard endovascular techniques in surgically-created carotid aneurysms in canines. Device performance and procedural angiographic data were collected. Animals were survived through 30, 90, or 180 days when follow-up angiography was performed followed by sacrifice and histopathologic evaluation.

Results 38 aneurysms in 22 animals were evaluated. The average dome size was 7.5 mm (SD: 1.2; range: 5.3–10.4) with an average neck of 4.2 mm (SD: 0.7; range: 2.8–6.1). There was no vasospasm, parent vessel thrombus or device migration during the procedure. In 27 aneurysms (71%), one coil was implanted. 35 aneurysms (92%) required two or fewer coils. Implanting physician ratings of device usability factors averaged 4.7 out of a maximum rating of 5.

At follow-up, 25 aneurysms (69%) showed angiographic occlusion of 90–100%. Subsequent histologic analysis demonstrated that 27 aneurysms (75%) were completely occluded with mature fibrous tissue. Two device migrations occurred in the post-operative period. No evidence of thrombosis or device corrosion was found in any animal. Inflammation was minimal and of a chronic nature.

Conclusion The technical feasibility of this embolization coil for occlusion of saccular aneurysms was demonstrated and usage ratings were positive. In contrast to reports of platinum coils in aneurysms of similar size, relatively few devices were required for each aneurysm; most required only one or two coils.

The device was effective at all chronic follow-up time points, with at least two-thirds of aneurysms showing 90% or greater occlusion. Complete aneurysm occlusion with organised fibrocellular tissue seen in the majority of cases may result in a permanent and stable occlusion that could result in fewer recanalizations and minimise the need for re-treatments. Overall, this initial report of preclinical outcomes with a new embolization coil reveals promising results.

Disclosures R. Jahan: 2; C; Covidien, Medina Medical, Stryker.