Four-Year Follow-Up on the First-in-Human Experience With Nautilus Intrasaccular System Assisted Coiling for Unruptured Intracranial Aneurysms

Background: The authors present the long-term (4 year) results of a first-in-man, single-center case series with the Nautilus Intrasaccular System for the embolization of wide-neck intracranial aneurysms. Methods: From February 2018 to July 2018, the authors enrolled 5 patients into a first-in-human study of the Nautilus device. After treatment, patients underwent 6 months with digital subtraction angiography and 3 years with magnetic resonance angiography according to institutional standard of care. Occlusion rates were core-laboratory adjudicated for the digital subtraction angiography and independently assessed by a neurointerventionalist not part of the care team for the magnetic resonance angiography. Neurological outcome (modified Ranking scale score) was evaluated at 24 hours, 7 days, 6 months, and 1, 2, 3, and 4 years, and adverse events were collected during the first 6 months post treatment. Results: Five patients with unruptured, wide-necked aneurysms were treated and followed up for 4 years. Aneurysm locations included basilar bifurcation (2 of 5), internal carotid artery terminus (1 of 5), superior cerebellar artery (1 of 5), and the anterior communicating artery (1 of 5). The average aneurysm size was 7.6 mm and the average neck diameter was 5.2 mm. Immediate complete and near-complete occlusion (Raymond-Roy classification class I and II) was achieved in 80% (4 of 5) of the aneurysms. Occlusion results improved at 6 months and remained stable at 3 years, without retreatment (Raymond-Roy classification class I 80%, class I and II 100%). All patients maintained good neurological outcome at all follow-ups (modified Ranking scale 0). Conclusion: This initial clinical experience provides early evidence of the long-term safety and effectiveness of the new intrasaccular neck bridging device, Nautilus. The Nautilus appears to add a simple, safe, and effective option and solution to the coil embolization of the wide-neck aneurysm.