Use of the Neuroform Atlas Stent or LVIS Jr Stent for Treatment of Unruptured Intracranial Aneurysms in Parent Arteries of <2 mm in Diameter: A Multicenter Experience

Abstract

Background and purpose: The Neuroform Atlas stent and the LVIS Jr stent are intracranial microstent systems for the treatment of wide-neck intracranial aneurysms. Hence, this study aimed to compare the efficacy and safety of the Neuroform Atlas stent and the LVIS Jr stent for the treatment of unruptured intracranial aneurysms in parent arteries of <2 mm in diameter.

Materials and methods: From March 2022 to April 2023, the clinical and imaging data of 135 patients with unruptured intracranial aneurysms treated with stent-assisted coiling using the Neuroform Atlas or LVIS Jr stent in parent arteries of <2 mm in diameter were retrospectively analyzed. Stent apposition was evaluated by high-resolution conebeam CT (HR-CBCT). Immediate aneurysm-embolization attenuation and occlusion at 6-month follow-up were evaluated using 2D DSA and the modified Raymond-Roy classification. Adverse events were recorded. Multivariate logistic regression analysis was undertaken to determine the independent factors affecting incomplete stent apposition.

Results: One hundred thirty-five patients (135 aneurysms) underwent stent-assisted coiling (66 Neuroform Atlas stents and 69 LVIS Jr stents). Intraoperative HR-CBCT showed that 1 Neuroform Atlas stent and 11 LVIS Jr stents had incomplete stent apposition at the aneurysm neck (P < .05). Perioperative complications occurred in 3 cases (2.22%). These comprised 2 cases of neurologic complications (1 case of distal intracranial vascular embolism and 1 case of cerebral parenchymal hemorrhage) and 1 case of severe postprocedural gastrointestinal hemorrhage. DSA follow-up showed 3 cases of aneurysm recurrence in the LVIS Jr group. Multivariate regression analysis showed that a stent angle of ≥75° (OR, 23.963; P = .005) or a parent artery diameter mismatch ratio of ≥1.25 (OR, 8.043; P = .037) were risk factors for incomplete stent apposition, especially for the LVIS Jr stent (OR, 20.297; P = .015).

Conclusions: The Neuroform Atlas stent and LVIS Jr stent are efficacious in the treatment of unruptured intracranial aneurysms in parent arteries of <2 mm in diameter. Apposition of the LVIS Jr stent was worse than in the Neuroform Atlas stent at the neck of some aneurysms.

FIG 1.

Flow chart of patient selection.

FIG 2.

Use of the Neuroform Atlas stent in SAC for the treatment of an unruptured anterior communicating artery aneurysm. A, 2D DSA of the right ICA shows the right A1 artery to be slender and the anterior communicating artery to be open. B, 2D DSA of the left ICA shows an aneurysm of the anterior communicating artery of 2.2 × 4.5 mm. The anterior communicating artery sends out a median callosal artery and the bilateral A2 arteries together to form a triploid anterior cerebral artery (aneurysm is shown by a white arrow). C and D, 3D DSA shows the position between the 3 A2 arteries and the aneurysms (blue dashed line denotes the stent-placement area, the parent artery diameter is 1.91 mm, and the diameter mismatch ratio is 1.09). E, SAC using a Neuroform Atlas stent (3.0 × 24 mm) was performed, and the occlusion attenuation of the aneurysm was Raymond-Roy class I (white arrows indicate the ends of the stent). F and G, HR-CBCT with diluted contrast media shows complete stent apposition and satisfactory protection of the coils at the aneurysm neck (the stent wire at the aneurysm neck is indicated by white arrows). H, DSA follow-up at 6 months shows the stent patency and well-healed aneurysm (Raymond-Roy class I).

FIG 3.

Use of the LVIS Jr stent in SAC for the treatment of an unruptured A2-segment aneurysm. A and B, 2D DSA and 3D DSA of the right ICA show an A2-segment aneurysm of the right anterior cerebral artery, with an irregular shape and a size of 1.5 × 2.7 mm. The parent artery diameter is 1.79 mm, and the diameter mismatch ratio is 1.15 (aneurysm is shown by a white arrow). C, SAC using a LVIS Jr stent (2.5 × 13 mm) was performed, and the aneurysm occlusion attenuation was Raymond-Roy class I (white arrows indicate the ends of the stent). D, HR-CBCT with diluted contrast media shows that the stent was completely deployed and stent angles were 43.34° (the stent angles are indicated by a white arrow). E, HR-CBCT shows complete stent apposition at the aneurysm neck and the coils protected satisfactorily (stent wire at the aneurysm neck is indicated by white arrows). F. DSA follow-up at 6 months shows stent patency, and the aneurysm has healed well (Raymond–Roy class I).