Ultra-small diameter coils for treatment of intracranial aneurysms.

This study reports our initial clinical experience treating very small intracranial aneurysms using only Target® Nano™ coils. Retrospective angiographic and clinical analysis was performed on a non-randomized single arm registry of all intracranial aneurysms treated with only Target® Nano™ coils (1 mm and 1.5 mm diameter only) during a 12 month period at two academic hospitals. Fourteen patients with 14 intracranial aneurysms were treated. The maximum diameter of saccular aneurysms treated ranged from 1.5 to 3.5 mm; minimum aneurysm diameter was 1.1 to 2 mm. The immediate complete aneurysm occlusion rate was 86% (12/14), and a small residual within the aneurysm was seen in 14% (2/14) of cases. Packing density from coils ranged between 24% and 83% (mean 51%). The immediate complication rate was 0% (0/14). The angiographic/MR angiography follow-up period was 22 to 70 weeks (mean 37 weeks) with an overall complete occlusion rate of 9/11 (81%), recurrence in 18% (2/11), and lack of follow-up in three cases, two due to death during hospitalization and one procedure not yet due for imaging follow-up. Both patients who died presented with brain aneurysm ruptures prior to treatment. Both recurrences were retreated with repeat coiling procedures. Our initial results using only Target® Nano™ coils for the endovascular treatment of very small intracranial aneurysms have demonstrated initial good safety and efficacy profiles.