Flow Diversion for Intracranial Aneurysms

Abstract

Abstract-The introduction of flow diverters for treatment of intracranial aneurysms represents a major paradigm shift in the treatment of these lesions. The theoretical hallmark of flow diverters is the treatment of the diseased segment harboring the aneurysm instead of treating the aneurysm itself. Flow diverters are designed to induce disruption of flow near the aneurysm neck while preserving flow into parent vessel and adjacent branches. After flow diversion, intra-aneurysmal thrombosis occurs, followed by shrinkage of the aneurysmal sac as the thrombus organizes and retracts. Preliminary clinical series document effective treatment of wide-neck and/or large and giant aneurysms with acceptable complication rates. However, several questions remain unanswered related to the incidence and mechanisms of aneurysm rupture after treatment with flow diverters, fate of small perforating vessels, and long-term patency rates. (Stroke. 2011;42: 2363-2368.)

Enhanced Aneurysmal Flow Diversion Using a Dynamic Push-Pull Technique: An Experimental and Modeling Study

“…With regard to the clinical implications of flow reduction, it is understood that more flow reduction leads to more immediate and complete thrombotic occlusion, therefore avoiding the complications related to aneurysm rupture. 11,12 The orifice coverage of the first clinical case matched the current high-compaction mesh of the sidewall aneurysm (46% versus 50%), indicating comparable flow reduction. The low-compaction mesh of the other case was favorable for branch vessel preservation, but with compromised flow reduction.…”

Patency of the Anterior Choroidal Artery after Flow-Diversion Treatment of Internal Carotid Artery Aneurysms

“…10 Previous clinical, animal, and computational studies have examined the propensity for branch artery occlusion following flow-diversion implantation. 5,6,11,12 Kallmes et al 13,14 found that on occlusion of lumbar branch vessels in the rabbit aorta with overlapping flow-diversion devices, these perforating vessels remained patent on follow-up. While a device placed across the origin of a perforating vessel (traditionally considered end vessels with no distal collaterals) may maintain flow across the ostium due to a pressure gradient across its ostium, the same is not true when larger vessels like the ophthalmic artery and the posterior communicating artery (which often have significant distal collateral potential) are covered by these devices.…”

“…[1][2][3][4] Flow diverters limit aneurysmal blood flow but maintain blood flow into large vessels and perforating vessels covered by the device. 5 Although many in vitro and experimental models have demonstrated long-term patency rates of branch vessels covered by the PED, the long-term patency of major branch vessels is not well-established. [6][7][8] In this study, we assessed the immediate and long-term patency rates of the anterior choroidal artery (AchoA) in patients following the placement of a PED across the AchoA ostium.…”

Flow-Diverter Stents for the Treatment of Saccular Middle Cerebral Artery Bifurcation Aneurysms

“…19 They have been designed to induce aneurysm sac thrombosis through flow disruption at the level of the neck, while preserving normal flow into parent vessels and adjacent branches. 20 Few studies have been published concerning FDS use for bifurcation lesion treatment, to our knowledge. In this report, our aim was to evaluate the feasibility, safety, and efficacy of the use of the FDSs for MCA saccular bifurcation aneurysms, with special consideration regarding the effects on the covered branches.…”