O-019 Novel non-occlusive temporary endoluminal neck protection device to assist in the treatment of wide necked aneurysms in a canine model

Introduction Current endovascular treatment of wide necked aneurysms often requires the use of an adjuvant device. Balloon assist technique requires temporary occlusion of the parent vessel. Intravascular stents require the use of antiplatelet medication. A novel device which achieves temporary neck protection without parent vessel occlusion or antiplatelet medication is examined in a canine model. Method 20 sidewall, wide necked aneurysms were created in 10 canines, one in each carotid artery, using a vein graft technique and allowed to mature. In each canine, one aneurysm was catheterized with a microcatheter while the temporary aneurysm neck bridge system (TANBS) was unsheathed across the neck of the aneurysm and the aneurysm was coiled. The second aneurysm in each canine was coiled without an adjunctive device. The TANBS was assessed for coil herniation, coil entrapment within the device, trackability, deliverability, TANBS deployability, TANBS recapturabilty and radio-opacity. The five animals were sacrificed acutely and five were sacrificed at 28 days and the carotid artery was explanted and sent for necropsy to assess for injury to the endothelium. Results There were 17 aneurysms present for coiling out of the 20 aneurysms originally created. Three aneurysms thrombosed were occluded on angiography at the time of coiling. Ten of the aneurysms, one in each of the canines, were coiled to occlusion while the TANBS device was deployed across the neck of the aneurysm. The seven remaining aneurysms located on the contralateral carotid artery were coiled to occlusion without assistance. The TANBS was successfully moved through the delivery, navigated into position across the aneurysm neck, deployed, resheathed and removed without adverse events in all cases. The coils were successfully placed into the aneurysms without evidence of coil herniation around the device or through its interstices. During device resheathing there was no evidence of interaction with the deployed coils as evidenced by movement of a coil loop or change in configuration of the coil mass. There was no change in the aneurysm occlusion result following the removal of the device. The radio-opacity of the device was adequate using GE/OEC 9800 C-Arm. Angiography did not reveal evidence of vasospasm or vessel dissection following removal of the device. Two coiled aneurysm in each group had mild fibroblasts on histology. The largest aneurysm was associated with the greatest degree of fibrosis. Three specimens in two canines were associated with severe inflammation, with both aneurysms in one canine, and the control aneurysm in a second animal. A third animal had a moderate–severe inflammatory response in the TANBS group. All other aneurysms were associated with minimal or mild inflammatory response. Overall, fibrosis was greatest in the chronic (28 day) group, while inflammation was most prominent in the acute group. There were no cases of parent vessel endothelial injury, perforation or intramural dissection. Conclusion The TANBS device was technically successful in all cases and provided parent artery protection as it was intended with no adverse events related to its use. Necropsy demonstrated that there was no evidence of endothelial injury related to the device.