Parent Artery Straightening after Flow-Diverter Stenting Improves the Odds of Aneurysm Occlusion

Abstract

BACKGROUND AND PURPOSE: Intracranial stents for the treatment of aneurysms can be responsible for parent artery straightening, a phenomenon with potential consequences for aneurysmal occlusion. We aimed to evaluate parent artery straightening following flow-diverter stent placement in patients with intracranial aneurysms and explored the association between parent artery straightening and subsequent aneurysm occlusion. MATERIALS AND METHODS:All patients treated with flow-diverter stents for anterior circulation aneurysms located downstream from the carotid siphon between January 2009 and January 2018 were screened for inclusion. Parent artery straightening was defined as the difference (a-b ) in the parent artery angle at the neck level before (a angle) and after flow-diverter stent deployment (b angle). We analyzed the procedural and imaging factors associated with parent artery straightening and the associations between parent artery straightening and aneurysmal occlusion.RESULTS: Ninety-five patients met the inclusion criteria (n ¼ 64/95 women, 67.4%; mean age, 54.1 [SD, 11.2] years) with 97 flow-diverter stents deployed for 99 aneurysms. Aneurysms were predominantly located at the MCA bifurcation (n ¼ 44/95, 44.4%). Parent artery straightening was found to be more pronounced in patients treated with cobalt chromium stents than with nitinol stents (P ¼ .02). In multivariate analysis, parent artery straightening (P = .04) was independently associated with aneurysm occlusion after flow-diverter stent deployment. CONCLUSIONS:The use of flow-diverter stents for distal aneurysms induces a measurable parent artery straightening, which is associated with higher occlusion rates. Parent artery straightening, in our sample, appeared to be more prominent with cobalt chromium stents than with nitinol stents. This work highlights the necessary trade-off between navigability and parent artery straightening and may help tailor the selection of flow-diverter stents to aneurysms and parent artery characteristics.

Enterprise Treatment for Recurrent Basilar Tip Aneurysm after PulseRider-assisted Coil Embolization: A Case Report

“… 13 ) It has also been reported that parent artery straightening is likely to be involved in higher occlusion rates in flow-diverter stents. 15 ) Specifically, it has been shown that a vessel angle of 20° or more likely indicates stable aneurysms, regardless of neck or aneurysm size. 16 ) In our case, the angle actually changed by more than 20° ( Fig.…”

Patient outcomes after treatment of brain aneurysm in small diameter vessels with the silk vista baby flow diverter: A systematic review

“…[26][27][28] The SVB is a 48 self-expandable, braided construct composed of drawn filled tubes (DFTs) of platinum-filled nitinol, with the latter component contributing to elasticity and shape memory. 29 The mechanical properties and design of the stent facilitate visualization of the device, navigability, and controlled deployment. These characteristics are of great utility during the treatment of aneurysms located in small vessels, as some technical limitations are unique to this subset of aneurysms.…”

In vitro flow diversion effect of the ReSolv stent with the shelf technique in a bifurcation aneurysm model

“…Michelozzi et al also reported a high occlusion rate of 92% occlusion in patients with at least 12 months of follow-up 13. These studies and others have suggested that complex interactions between mesh density of the stent, flow dynamics, geometrical modification (straightening) of the parent artery, changes in wall pulsatility, newer generation antiplatelet agents, and aneurysm neck coverage can affect occlusion rates 14 15. In general, however, aneurysm neck coverage cannot be manipulated by existing flow-diverting stents.…”