Introduction The Surpass Evolve flow diverter (FD) is a 64-wire cobalt-chromium device that, compared with its predecessor, was designed to improve ease of deployment and conformability. Data on procedural outcomes and aneurysm obliteration rate remain limited.

Purpose To describe the procedural outcomes, including 6- and 12-month obliteration rates, for patients who underwent Surpass Evolve FD embolization of an unruptured anterior circulation aneurysm

Materials and Methods All consecutive patients with an unruptured anterior circulation aneurysm who were treated with the Surpass Evolve FD between August 2020 and December 2022 at a single tertiary center were included. Patients with a traumatic dissection or pseudoaneurysm, ruptured anterior circulation aneurysm, or posterior circulation aneurysm were excluded. All patients at our institution standardly undergo six- and twelve-month clinical and angiographic follow up. Demographic and clinical features, aneurysm morphology, arterial access, procedural factors and outcome were extracted from our departmental neurointerventional database. Summary statistics included frequencies, and measures of central tendency and dispersion as appropriate.

Results Seventy-seven (77% female, mean age 58.3 years ± 15.4) underwent elective Surpass Evolve flow diversion for an unruptured anterior circulation aneurysm. In 64 (83%) patients, a native aneurysm was flow-diverted, and in 13 (17%) patients, FD was performed for a recurrent aneurysm. Distribution of aneurysm location was: supraclinoid ICA (58%), cavernous ICA (17%), cervical ICA (13%) and anterior cerebral artery-anterior communicating artery complex (12%). Fifty-one (66%) patients underwent left-sided intervention. Mean aneurysm maximal diameter was 7.9 ± 5.4 mm. The majority of patients (65, 84%) underwent radial arterial access.Fifty-two patients (68%) had one FD placed, and 25 (32%) required two diverters. Balloon angioplasty or J-wire manipulation was used to enhance apposition in 47 (61%) cases. Adjunctive coiling or stenting was used in 16 (21%) patients. To date, 54 (70%) patients have had a follow up angiogram (mean 0.64 years ± 0.18 from intervention); in 7 (13%) patients, there was mild non-flow-limiting stenosis. Based on the Raymond-Roy Occlusion Classification, 34 (63%) had complete occlusion, 2 (4%) had a residual neck, and 18 (33%) had residual aneurysm. Twenty-one (27%) patient have undergone 12-month angiograms to date (mean 1.4 years ± 0.35 from intervention); one patient had mild non-flow-limiting stenosis. Fifteen (71%) had complete occlusion, one had a residual neck, and 4 (19%) had residual aneurysm.

Conclusion The Surpass Evolve FD is associated with favorable occlusion rates at six months and even more so at twelve months. In our early experience, complication rates are well within the acceptable limits.

Disclosures L. Verhey: None. A. Sewell: None. P. Mazaris: None. J. Singer: None.