Pipeline embolization device diameter is an important factor determining the efficacy of flow diversion treatment of small intracranial saccular aneurysms

Abstract

ObjectiveFlow diversion using the Pipeline embolization device (PED) has become a widely used treatment method for intracranial aneurysms. However, a subset of aneurysms will fail to occlude following treatment and the factors that influence the efficacy of flow diversion remain uncertain. As smaller diameter PEDs inherently have greater metal density than larger devices, we elected to investigate whether PED diameter influences treatment efficacy when using a single device. We also evaluated other factors that may influence treatment outcomes with PED.MethodsWe retrospectively evaluated all patients treated for an intracranial saccular aneurysm at our institution with a single PED at least 12 months prior to the time of data collection. Patients treated with multiple devices, adjunctive coiling, traumatic and fusiform target aneurysms, as well as patients with inadequate imaging follow-up (<12 months) were excluded.Results158 aneurysms in 124 patients (128 treatments) met the inclusion criteria for our study. 123 aneurysms (80%) were occluded over an average follow-up of 26.6 months. Multivariable logistic regression showed that branch vessel incorporation into the target aneurysm sac (p<0.001, OR=0.15) was significantly associated with aneurysm persistence, while smaller PED diameter was significantly associated with aneurysm occlusion (p=0.008; OR=0.30).ConclusionsPED diameter significantly impacts outcomes when using a single device for the treatment of small anterior circulation intracranial saccular aneurysms, most likely due to the inherent greater metal density of smaller devices. This factor should be taken into account when planning endovascular aneurysm treatment with PED.

Complex cerebral aneurysms: intra-luminal reconstruction using Pipeline flow-diverting stent and the obliteration mechanism

“…7 Some authors found smaller PFS diameter promotes occlusion of small anterior circulation intracranial saccular aneurysms, most likely due to the inherent greater metal density of smaller devices. 1 For distal cerebral artery aneurysms, such as in the MCA, posterior cerebral artery, anterior cerebral artery (A1/A2, pericallosal artery), and the posterior inferior cerebellar artery, PFS use was also associated with good clinical outcome. 17 Twenty procedures were performed on 18 patients, 11 with prior PFS, seven with a vascular reconstruction device, and two previously treated with both.…”

“…Patients with complex cerebral aneurysms can now be treated intravascularly with flow-diverting stents as an alternative treatment to coiling with or without stenting. 1–6 The Medtronic Pipeline flow-diverting stent (PFS; Medtronic, Dublin, Ireland) is the leading braided flow-diverting stent on the market, and this device has had a positive impact on aneurysm repair in the past few years. 4 In a systematic review of early studies (2009–2014), 4 29 studies including 1524 patients with 3 to 62 months of follow-up were analyzed.…”

Silk Vista Baby Is a Safe and Technically Feasible Flow Diverting Stent for Distal Aneurysm Treatment

“…Additionally, when using FDs in small vessels, it is imperative to understand and consider the effects of oversizing on the FD. Oversizing may result in lengthening of the device, subsequently increasing its porosity and likelihood of aneurysm persistence ( 6 , 7 ). It should be highlighted that in this study, measurements were not made on volume rendering images; rather, they were made on the axial plane after reconstruction of the image using the “Vessel analysis” software.…”

“…Flow diversion strategies have gained popularity for cases where coil embolization might be more difficult or likely to fail, such as with large neck side-wall aneurysms, bifurcation aneurysms, or recurrent aneurysms that have already been treated with coil embolization (3)(4)(5). To-date, relatively limited data are available on the feasibility, safety, and effectiveness of flow diversion in aneurysms arising from distal, small-caliber arteries; deploying FDs in such vessels comes with the risk that the FD may become elongated, thus increasing its porosity and lowering the chances of intra-aneurysmal thrombosis (6,7).…”

Association Between Aneurysmal Haemodynamics and Device Microstructural Characteristics After Flow-Diversion Treatments With Dual Stents of Different Sizes: A Numerical Study

“…Treatments with dual stents of different diameters may result in distinct haemodynamic outcomes, due to the variety of wire configurations following multi-stent implantation ( Shapiro et al, 2014 ; Kole et al, 2019 ; Zhang et al, 2020 ). However, few studies have investigated such variations in stent morphology and the subsequent IA haemodynamics; nor has the correlation between them been established.…”