Background Flow diverting devices have gained widespread use in the treatment of unruptured intracranial aneurysms. In particular, the Surpass Streamline flow diverter (SSFD) possesses four attributes, (1) utilization of an over-the-wire (OTW) delivery system, (2) greater device length, (3) larger potential diameter, and (4) propensity to open in tortuosity, that may offer an important advantage compared to other flow diverters available on the U.S. market. These characteristics can prove beneficial in the treatment of complex pathologies.

Objective This technical series aims to demonstrate how the unique attributes of SSFD can facilitate safe and effective treatment of anatomically complex cerebrovascular pathologies.

Methods A retrospective review was conducted of cases at The University of Kansas Health Systems from 2019 to 2021 in which patients underwent embolization with the SSFD system. Example cases highlighting the unique properties of the Surpass Streamline were selected for presentation.

Results We selected four cases with challenging anatomical considerations in which we leveraged the unique properties of the SSFD system. Case 1 leveraged greater potential device diameter to embolize a large, recurrent vertebral artery aneurysm. Angiography at 6-months post-treatment revealed near complete occlusion of the right vertebral artery aneurysm with complete occlusion at 1 year with the SSFD stent remaining widely patent. Case 2 leveraged greater device length and ability to open in tortuosity to manage a symptomatic 20mm cavernous carotid aneurysm. Imaging at both 6- and 12-month follow-ups revealed patent stents with no significant change in the aneurysm, but MRI at 2 years demonstrated aneurysm thrombosis. Case 3 utilized greater device diameter, length, and the OTW delivery system to treat a giant intracranial aneurysm previously treated by surgical ligation and high-flow bypass. At 5-months, the pulsatile neck mass had markedly reduced in size. Angiography at 5 months post-procedure revealed return of laminar flow as the vein graft had healed around the stent construct. The left MCA aneurysm progressed to complete occlusion around the stent construct. Case 4 employed greater diameter, length, and the OTW delivery system to treat a giant, symptomatic, dolichoectatic vertebrobasilar aneurysm. At 6 months post-procedure, the stent construct was patent. Excluded portions of the aneurysm were non-filling aside from a small area of residual aneurysm sac adjacent to the stents at the junction of the medial and superior stents. 12-month follow-up imaging revealed no further changes to construct patency or aneurysm size. All four patients tolerated the procedure with no new deficit and exhibited continual neurologic improvement over time. Embolization using the SSFD system resulted in successful and safe management in these challenging cases.

Conclusion The SSFD has several unique attributes that can prove beneficial in the management of complex cerebrovascular pathologies. Increased awareness of these attributes may allow for a larger number of cases to be treated with the proven mechanism of flow diversion.

Disclosures C. Lei: None. C. Heskett: None. L. Fry: None. A. Brake: None. F. De Stefano: None. J. Peterson: None. K. Ebersole: 6; C; Microvention, Stryker.