Endovascular treatment of aneurysm remnants with the Contour Neurovascular System after previous treatment.

Objective: The Contour Neurovascular System (CNS) is a novel intrasaccular flow disrupting device with a semi-3D cup-like shape for the treatment of intracranial aneurysms. This study investigates the potential and limitations of the CNS for embolization of aneurysm remnants after previous treatment.

Methods: Ten cases of aneurysm recurrence treatment with the CNS were analyzed from a single-center database. Technical success, procedural aspects, complications, and angiographic results were evaluated.

Results: The aneurysms (median width: 5.3 mm, median neck width: 3.8 mm) were located in the anterior communicating artery (4), basilar tip (3), internal carotid artery (1), middle cerebral artery (1), and superior cerebellar artery (1). The aneurysms were initially treated endovascularly (9) and by clipping (1). Retreatment failed in one case where the smallest available CNS proved to be too small and had to be removed. Adjunctive coiling was performed in two large remnants of partially thrombosed basilar tip aneurysms. There were no procedural complications or morbidity. At a median follow-up of nine months, 4/8 (50%) aneurysms were completely occluded, 2/8 (25%) had neck remnants, and 2/8 (25%) had aneurysm remnants. The two aneurysm remnants were retreated with coiling and stent-assisted coiling, respectively.

Conclusions: CNS treatment of aneurysm remnants may be feasible, especially for shallow, wide-necked aneurysm geometries. Further studies are needed to identify aneurysm subsets that benefit from CNS retreatment and to define mid- and long-term occlusion rates.