First Experience of Three Neurovascular Centers With the p64MW-HPC, a Low-Profile Flow Diverter Designed for Proximal Cerebral Vessels With Antithrombotic Coating

Background: In the last decade, flow diversion (FD) has been established as hemodynamic treatment for cerebral aneurysms arising from proximal and distal cerebral arteries. However, two significant limitations remain—the need for 0.027” microcatheters required for delivery of most flow diverting stents (FDS), and long-term dual anti-platelet therapy (DAPT) in order to prevent FDS-associated thromboembolism, at the cost of increasing the risk for hemorrhage. This study reports the experience of three neurovascular centers with the p64MW-HPC, a FDS with anti-thrombotic coating that is implantable via a 0.021” microcatheter.Materials and methods: Three neurovascular centers contributed to this retrospective analysis of patients that had been treated with the p64MW-HPC between March 2020 and March 2021. Clinical data, aneurysm characteristics, and follow-up results, including procedural and post-procedural complications, were recorded. The hemodynamic effect was assessed using the O'Kelly–Marotta Scale (OKM).Results: Thirty-two patients (22 female, mean age 57.1 years) with 33 aneurysms (27 anterior circulation and six posterior circulation) were successfully treated with the p64MW-HPC. In 30/32 patients (93.75%), aneurysmal perfusion was significantly reduced immediately post implantation. Follow-up imaging was available for 23 aneurysms. Delayed aneurysm perfusion (OKM A3: 8.7%), reduction in aneurysm size (OKM B1-3: 26.1%), or sufficient separation from the parent vessel (OKM C1-3 and D1: 65.2%) was demonstrated at the last available follow-up after a mean of 5.9 months. In two cases, device thrombosis after early discontinuation of DAPT occurred. One delayed rupture caused a caroticocavernous fistula. The complications were treated sufficiently and all patients recovered without permanent significant morbidity.Conclusion: Treatment with the p64MW-HPC is safe and feasible and achieves good early aneurysm occlusion rates in the proximal intracranial circulation, which are comparable to those of well-established FDS. Sudden interruption of DAPT in the early post-interventional phase can cause in-stent thrombosis despite the HPC surface modification. Deliverability via the 0.021” microcatheter facilitates treatment in challenging vascular anatomies.

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Rescue Therapy for Procedural Complications Associated With Deployment of Flow-Diverting Devices in Cerebral Aneurysms

Operative Neurosurgery ◽

10.1093/ons/opy020 ◽

2018 ◽

Vol 15 (6) ◽

pp. 624-633 ◽

Cited By ~ 10

Author(s):

Fawaz Al-Mufti ◽

Krishna Amuluru ◽

Eric R Cohen ◽

Vikas Patel ◽

Mohammad El-Ghanem ◽

...

Keyword(s):

Rescue Therapy ◽

Significant Risk ◽

Cerebral Aneurysms ◽

Flow Diverter ◽

Side Branch ◽

Parent Vessel ◽

Vessel Injury ◽

Procedural Complications ◽

Background Material ◽

Device Deployment

Abstract Flow diverting devices (FDDs) have revolutionized the treatment of morphologically complex intracranial aneurysms such as wide-necked, giant, or fusiform aneurysms. Although FDDs are extremely effective, they carry a small yet significant risk of intraprocedural complications. As the implementation of these devices increases, the ability to predict and rapidly treat complications, especially those that are iatrogenic or intraprocedural in nature, is becoming increasingly more necessary. Our objective in this paper is to provide a descriptive summary of the various types of intraprocedural complications that may occur during FDDs deployment and how they may best be treated. A systematic and qualitative review of the literature was conducted using electronic databases MEDLINE and Google Scholar. Searches consisted of Boolean operators “AND” and “OR” for the following terms in different combinations: “aneurysm,” “endovascular,” “flow diverter,” “intracranial,” and “pipeline.” A total of 94 papers were included in our analysis; approximately 87 of these papers dealt with periprocedural endovascular (mainly related to FDDs) complications and their treatment; 7 studies concerned background material. The main categories of periprocedural complications encountered during deployment of FDDs are failure of occlusion, parent vessel injury and/or rupture, spontaneous intraparenchymal hemorrhage, migration or malposition of the FDDs, thromboembolic or ischemic events, and side branch occlusion Periprocedural complications occur mainly due to thromboembolic events or mechanical issues related to device deployment and placement. With increasing use and expanding versatility of FDDs, the understanding of these complications is vital in order to effectively manage such situations in a timely manner.

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FRED Italian Registry: a multicenter experience with the flow re-direction endoluminal device for intracranial aneurysms

Journal of Neurosurgery ◽

10.3171/2019.1.jns183005 ◽

2020 ◽

Vol 133 (1) ◽

pp. 174-181 ◽

Cited By ~ 5

Author(s):

Mariangela Piano ◽

Luca Valvassori ◽

Emilio Lozupone ◽

Guglielmo Pero ◽

Luca Quilici ◽

...

Keyword(s):

Adverse Event ◽

Endovascular Treatment ◽

Intracranial Aneurysms ◽

Cerebral Aneurysms ◽

Flow Diverter ◽

Anterior Circulation ◽

Cross Sectional ◽

Safety And Efficacy ◽

Mortality And Morbidity

OBJECTIVEThe introduction of flow-diverter devices (FDDs) has revolutionized the endovascular treatment of intracranial aneurysms. Here the authors present their Italian multicenter experience using the flow re-direction endoluminal device (FRED) in the treatment of cerebral aneurysms, evaluating both short- and long-term safety and efficacy of this device.METHODSBetween February 2013 and December 2014, 169 consecutive aneurysms treated using FRED in 166 patients were entered into this study across 30 Italian centers. Data collected included patient demographics, aneurysm location and characteristics, baseline angiography, adverse event and serious adverse event information, morbidity and mortality rates, and pre- and posttreatment modified Rankin Scale scores, as well as angiographic and cross-sectional CT/MRI follow-up at 3–6 months and/or 12–24 months per institutional standard of care. All images were reviewed and adjudicated by an independent core lab.RESULTSOf the 169 lesions initially entered into the study, 4 were later determined to be extracranial or nonaneurysmal by the core lab and were excluded, leaving 165 aneurysms in 162 patients treated in 163 procedures. Ninety-one (56.2%) patients were asymptomatic with aneurysms found incidentally. Of the 165 aneurysms, 150 (90.9%) were unruptured. One hundred thirty-four (81.2%) were saccular, 27 (16.4%) were fusiform/dissecting, and the remaining 4 (2.4%) were blister-like. One hundred thirty-seven (83.0%) arose from the anterior circulation.FRED deployment was impossible in 2/163 (1.2%) cases, and in an additional 4 cases (2.5%) the device was misdeployed. Overall mortality and morbidity rates were 4.3% and 7.3%, respectively, with rates of mortality and morbidity potentially related to FRED of up to 2.4% and 6.2%, respectively. Neuroimaging follow-up at 3–6 months showed complete or nearly complete occlusion of the aneurysm in 94% of cases, increasing to 96% at 12–24 months’ follow-up. Aneurysmal sac shrinkage was observed in 78% of assessable aneurysms.CONCLUSIONSThis preliminary experience using FRED for endovascular treatment of complex unruptured and ruptured aneurysms showed a high safety and efficacy profile that is comparable to those of other FDDs currently in use.

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The Silk Vista Baby – The UK experience

Interventional Neuroradiology ◽

10.1177/15910199211024061 ◽

2021 ◽

pp. 159101992110240

Author(s):

P Bhogal ◽

HLD Makalanda ◽

K Wong ◽

P Keston ◽

J Downer ◽

...

Keyword(s):

Vessel Diameter ◽

Flow Diverter ◽

Aneurysm Rupture ◽

Parent Vessel ◽

Anterior Circulation ◽

Clinical Complications ◽

Permanent Morbidity ◽

Mca Aneurysm ◽

The Uk

Background The Silk Vista Baby (SVB) flow diverter (FDS) is the only FDS deliverable via a 0.017 inch microcatheter and is specifically designed for the distal vasculature. We sought to evaluate the safety and efficacy of the SVB. Materials and Methods We performed a retrospective review to identify SVB cases at 4 tertiary neurosurgical centres within the U.K. Clinical, procedural, angiographic and follow-up data were collected. Results We identified 60 patients (35 female, 58%) of average age 54 ± 10.5 (range 30–72) with 61 aneurysms, 50 (81.9%) located in the anterior circulation. The majority of the aneurysms treated were unruptured (46, 75.4%) and saccular (46, 75.4%). Dome size was 6.2 ± 6.2 mm (range 1–36mm) and parent vessel diameter was 2.3 ± 0.4 mm (range 1.2-3.3 mm). An average number of 1.07 devices were implanted. Coils or other devices were implanted in 14 aneurysms (23.3%). At last angiographic follow-up (n = 55), 7.5 ± 4.2 months post-procedure, 32 aneurysms (57.1%) were graded as RRC I, 7 (12.5%) RRC II, and 17 RRC III (30.4%). Clinical complications, excluding death, were seen in 4 patients (6.8%) including 1 delayed aneurysm rupture and 3 symptomatic ischaemic events. Only one patient had permanent morbidity (mRS 1). 3 patients died during follow-up (5.1%); 2 deaths were related to the aneurysms (3.4%) – one ruptured dissecting MCA aneurysm, and one giant partially thrombosed posterior circulation aneurysm. 93% of patients were mRS ≤ 2 at last follow-up. Conclusion The SVB has high rates of technical success and an acceptable safety profile. Distal aneurysms may occlude slower due to relative oversizing of the devices.

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Stent-assisted coiling of cerebral aneurysms: a single-center clinical and angiographic analysis

Journal of NeuroInterventional Surgery ◽

10.1136/neurintsurg-2017-013272 ◽

2017 ◽

Vol 10 (7) ◽

pp. 687-692 ◽

Cited By ~ 23

Author(s):

Jun Wang ◽

Jan Vargas ◽

Alejandro Spiotta ◽

Imran Chaudry ◽

Raymond D Turner ◽

...

Keyword(s):

Multivariate Logistic Regression Analysis ◽

Cerebral Aneurysms ◽

Multivariate Logistic Regression ◽

Complete Occlusion ◽

Post Procedure ◽

Low Profile ◽

Nitinol Stents ◽

Grade Scale ◽

Procedural Complications

ObjectiveThis study retrospectively compared the clinical and angiographic outcomes of treating cerebral aneurysms with Neuroform (NEU), Enterprise (EP), and Low-profile Visualized Intraluminal Support (LVIS/LVIS Jr) stents.Materials and methodsWe conducted a retrospective analysis of a procedural database. All aneurysm procedures using any of the three types of self-expanding nitinol stents (NEU, EP and LVIS/LVIS Jr) were included. Intra-procedure complications, post-procedure complications, and angiographic results (Raymond–Roy grade scale, RRGS) were analyzed retrospectively. A multivariate logistic regression analysis was conducted to identify predictors of intra-procedure and post-procedure complications.ResultsTwo hundred and forty-three aneurysms in 229 patients treated with stent-assisted coiling were included (NEU group: 109 aneurysms; EP group: 61 aneurysms; LVIS/LVIS Jr: 73 aneurysms). The LVIS/LVIS Jr group was associated with the lowest rate of initial complete occlusion (RRGS I: 47.9%; 35/73). Follow-up showed the proportion of RRGS I increased for all stent groups but was greatest in the LVIS/LVIS Jr group. Overall, 17 intra-procedural complications were seen in 229 patients (7.4%) and 15 post-procedural complications were found in 198 patients at follow-up (7.6%), with no differences between stent groups. Thrombotic events were the most common complications and occurred in 13 patients (13/229, 5.7%).ConclusionsAll three types of stents used to treat cerebral aneurysms with unfavorable neck were safe and effective, providing suitable support for the coil mass. LVIS/LVIS Jr promotes better progressive aneurysm complete occlusion than the other two stents but seems to cause more common intra-procedural stent-related thrombotic events and fewer post-procedural complications.

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Indirect Flow Diversion for Off-Centered Bifurcation Aneurysms and Distant Small-Vessel Aneurysms, a Retrospective Proof of Concept Study From Five Neurovascular Centers

Frontiers in Neurology ◽

10.3389/fneur.2021.801470 ◽

2022 ◽

Vol 12 ◽

Author(s):

Stefan Schob ◽

Richard Brill ◽

Eberhard Siebert ◽

Massimo Sponza ◽

Marie-Sophie Schüngel ◽

...

Keyword(s):

Average Distance ◽

Cerebral Aneurysms ◽

Flow Diverter ◽

Flow Diversion ◽

Small Vessel ◽

Parent Vessel ◽

Therapeutic Success ◽

Subsequent Formation ◽

Procedural Complications

Background: Treatment of cerebral aneurysms using hemodynamic implants such as endosaccular flow disruptors and endoluminal flow diverters has gained significant momentum during recent years. The intended target zone of those devices is the immediate interface between aneurysm and parent vessel. The therapeutic success is based on the reduction of aneurysmal perfusion and the subsequent formation of a neointima along the surface of the implant. However, a subset of aneurysms–off-centered bifurcation aneurysms involving the origin of efferent branches and aneurysms arising from peripheral segments of small cerebral vessels–oftentimes cannot be treated via coiling or implanting a hemodynamic implant at the neck level for technical reasons. In those cases, indirect flow diversion–a flow diverter deployed in the main artery proximal to the parent vessel of the aneurysm–can be a viable treatment strategy, but clinical evidence is lacking in this regard.Materials and Methods: Five neurovascular centers contributed to this retrospective analysis of patients who were treated with indirect flow diversion. Clinical data, aneurysm characteristics, anti-platelet medication, and follow-up results, including procedural and post-procedural complications, were recorded.Results: Seventeen patients (mean age: 60.5 years, range: 35–77 years) with 17 target aneurysms (vertebrobasilar: n = 9) were treated with indirect flow diversion. The average distance between the flow-diverting stent and the aneurysm was 1.65 mm (range: 0.4–2.4 mm). In 15/17 patients (88.2%), perfusion of the aneurysm was reduced immediately after implantation. Follow-ups were available for 12 cases. Delayed opacification (OKM A3: 11.8%), reduction in size (OKM B1-3: 29.4%) and occlusion (D1: 47.1%) were observable at the latest investigation. Clinically relevant procedural complications and adverse events in the early phase and in the late subacute phase were not observed in any case.Conclusion: Our preliminary data suggest that indirect flow diversion is a safe, feasible, and effective approach to off-centered bifurcation aneurysms and distant small-vessel aneurysms. However, validation with larger studies, including long-term outcomes and optimized imaging, is warranted.

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Early clinical experience with the p48MW HPC and p64MW HPC flow diverters in the anterior circulation aneurysm using single anti-platelet treatment

Interventional Neuroradiology ◽

10.1177/15910199211029503 ◽

2021 ◽

pp. 159101992110295

Author(s):

Pervinder Bhogal ◽

Andrey Petrov ◽

Ganbaatar Rentsenkhu ◽

Baatarjan Nota ◽

Erdenebat Ganzorig ◽

...

Keyword(s):

Clinical Results ◽

Dome Height ◽

Anterior Circulation ◽

Post Procedure ◽

Neurological Morbidity ◽

Procedural Complications ◽

Previously Treated ◽

Flow Diverters ◽

Overall Mortality

Background The p64MW HPC and p48MW HPC flow diverters have reduced thrombogenicity due to hydrophilic coating. The purpose of this study was to evaluate its safety and efficacy in Mongolian patients under single antiplatelet therapy (SAPT) with prasugrel. Materials and methods We performed a retrospective review of patients enrolled into our prospectively maintained database to identify all patients treated with either the p48MW HPC or p64MW HPC under SAPT. We recorded baseline demographics, aneurysm size and location, procedural complications, angiographic and clinical results. Results 24 patients, (female = 21, 87.5%), age 48.2 ± 11.6 years (range 25–63) underwent treatment of 30 aneurysms with either p64MW HPC or p48MW HPC. All aneurysms were saccular with dome width 8.2 ± 6.5 (range 1.6–26.0 mm) and dome height 7.6 ± 6.7 (range 1.6–30.0 mm). None of the aneurysms were previously treated. The average PRU was 54.6 ± 31.2 (range 1–127) on pre-operative VerifyNow testing. Angiographic follow-up was available for 13 patients (17 aneurysms), 183 ± 36 days post-procedure, at which point 64.7% of aneurysms (n = 11/17) were completely occluded and 11.8% (n = 2/17) had only neck remnants resulting in 76.5% of aneurysms being adequately occluded A single intra-operative complication (4.2%) occurred however all patients were mRS ≤1 at last follow-up. There were two post-operative complications neither of which resulted in permanent neurological morbidity. There were no instances of post-operative aneurysmal rupture or delayed parenchymal haemorrhage. The overall mortality was 0%. Conclusion The efficacy and safety of p64MW HPC coated devices under SAPT is similar to uncoated flow diverters that require DAPT.

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Endovascular treatment of PICA aneurysms with a Low-profile Visualized Intraluminal Support (LVIS Jr) device

Journal of NeuroInterventional Surgery ◽

10.1136/neurintsurg-2015-012070 ◽

2015 ◽

Vol 8 (10) ◽

pp. 1030-1033 ◽

Cited By ~ 15

Author(s):

Edgar A Samaniego ◽

German Abdo ◽

Ricardo A Hanel ◽

Andrey Lima ◽

Santiago Ortega-Gutierrez ◽

...

Keyword(s):

Endovascular Treatment ◽

Acute Phase ◽

Posterior Inferior Cerebellar Artery ◽

Short Term ◽

Small Series ◽

Low Profile ◽

Procedural Complications ◽

Reconstructive Technique ◽

Pica Aneurysms

ObjectiveTo describe the treatment of posterior inferior cerebellar artery (PICA) aneurysms with the Low-profile Visualized Intraluminal Support Device (LVIS Jr) stent.Materials and methodsThe databases of three institutions were retrospectively reviewed. Patients who underwent endovascular treatment of PICA aneurysms using a reconstructive technique where the LVIS Jr stent was totally or partially deployed into the PICA were included in the analysis. Clinical presentation, aneurysm and PICA sizes, procedural complications, and clinical and angiographic follow-up information was recorded and analyzed.ResultsSeven patients who underwent endovascular treatment of PICA aneurysms with an LVIS Jr stent were identified. Four aneurysms were treated in the acute phase of subarachnoid hemorrhage (SAH). There were no symptomatic complications. One patient had spasm distal to the stent as a result of mechanical straightening of the vessel. One patient was treated in the acute phase of SAH and required a gycoprotein IIb/IIIa inhibitor after the stent was implanted. This patient needed to be re-treated to complete embolization. All patients had good clinical outcomes (Glasgow Outcome Scale 5). No in-stent stenosis or occlusion was seen on short-term angiographic follow-up and the aneurysms were occluded.ConclusionsThis small series suggests that the use of a reconstructive technique with the LVIS Jr stent for the treatment of PICA aneurysms is feasible, safe and effective in the short term.

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Abstract 120: Surpass Flow Diverter for Endovascular Treatment of Intracranial Aneurysms - A Multicenter Preliminary Clinical and Angiographic Experience in 161 Patients with 186 Aneurysms

Stroke ◽

10.1161/str.45.suppl_1.120 ◽

2014 ◽

Vol 45 (suppl_1) ◽

Author(s):

Ajay K Wakhloo ◽

Pedro Lylyk ◽

Joost de Vries ◽

Matthew J Gounis ◽

Alexandra Biondi ◽

...

Keyword(s):

Intracranial Aneurysms ◽

Experimental Studies ◽

Flow Diverter ◽

Posterior Circulation ◽

Parent Artery ◽

Anterior Circulation ◽

Neck Size ◽

Wide Range ◽

New Generation

Objective: Validated through experimental studies a new generation of flow diverters (Surpass™ FD) was evaluated for treatment of intracranial aneurysms (IA). We present our multicenter preliminary clinical and angiographic experience. METHODS: To achieve the calculated flow disruption between the parent artery and aneurysm for thrombosis, single FDs were placed endovascularly in parent arteries. Implants measured 2.5-5.3mm in diameter with a length of 10-80mm. Patients were enrolled harboring a wide range large and giant wide-neck, fusiform and multiple small and blister-type aneurysm. Clinical and angiographic follow-up were performed at 1-3, 6, and 12 months. RESULTS: A total of 186 consecutive IA in 161 patients (mean age 57.1 years) were treated at 33 centers. Fifty-three aneurysms were smaller than 5 mm, 64 were 5-9.9mm in diameter, 47 were 10-20mm in diameter, and 22 were larger than 20mm (10.4±0.7mm, neck size 6.0±0.5mm [mean±SEM]) . The aneurysms originated in 63.4% from the internal carotid artery; 22% and 14.5% of the lesions were located in the anterior circulation distal to Circle of Willis and posterior circulation respectively. Technical success was achieved in 182 aneurysms (98%); average number of devices used per aneurysm was 1.05. Permanent morbidity and mortality during the follow-up period of mean 8.4months (range 1-24 months) including periprocedural complications for patients with aneurysms of the anterior circulation were encountered in 5 (3.7%) and 2 (1.5 %) patients respectively and 1 (3.7%) and 4 (14.8%) respectively for patients with aneurysms of the posterior circulation location. One-hundred-ten patients (70.5%) harboring 127 (70.2%) were available for clinical and angiographic follow-up and showed a complete or near complete aneurysm occlusion in 63 (81.8%) of the ICA. Aneurysms of the ICA≥10mm that were completely covered by FD and not previously stent-treated with a minimum of 6 months follow-up available in 16 patients showed a complete obliteration in 81.3% (n=13) and >90% occlusion in remaining 3 patients. CONCLUSION: Preliminary data demonstrate high safety and efficacy of a new generation of FD for a wide range of IA of the anterior and posterior circulation with a single implant.

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Comparison of the In Vitro Hemodynamic Performance of New Flow Diverters for Bypass of Brain Aneurysms

Journal of Biomechanical Engineering ◽

10.1115/1.4006454 ◽

2012 ◽

Vol 134 (8) ◽

Cited By ~ 5

Author(s):

Asher L. Trager ◽

Chander Sadasivan ◽

Baruch B. Lieber

Keyword(s):

Cerebral Aneurysms ◽

Flow Diverter ◽

Parent Artery ◽

New Device ◽

Design Changes ◽

Hemodynamic Performance ◽

Braiding Angle ◽

Treatment For Cerebral Aneurysms

One possible treatment for cerebral aneurysms is a porous tubular structure, similar to a stent, called a flow diverter. A flow diverter can be placed across the neck of a cerebral aneurysm to induce the cessation of flow and initiate the formation of an intra-aneurysmal thrombus. This excludes the aneurysm from the parent artery and returns the flow of blood to normal. Previous flow diverting devices have been analyzed to determine optimal characteristics, such as braiding angle and wire diameter. From this information, a new optimized device was designed to achieve equivalent hemodynamic performance to the previous best device, but with better longitudinal flexibility to preserve physiological arterial configuration. The new device was tested in vitro in an elastomeric replica of the rabbit elastase induced aneurysm model and is now in the process of being tested in vivo. Particle image velocimetry was utilized to determine the velocity field in the plane of symmetry of the model under pulsatile flow conditions. Device hemodynamic performance indices such as the hydrodynamic circulation were evaluated from the velocity fields. Comparison of these indices with the previous best device and a control shows that the significant design changes of the device did not change its hemodynamic attributes (p > 0.05).

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Transcirculation Silk Vista Baby-assisted coiling in half-T configuration for the treatment of posterior communicating artery aneurysms associated with a fetal posterior circulation: An alternative flow diversion strategy

Interventional Neuroradiology ◽

10.1177/1591019920961889 ◽

2020 ◽

pp. 159101992096188

Author(s):

Mario Martínez-Galdámez ◽

Miguel Schüller-Arteaga ◽

Jorge Galván-Fernández ◽

Vladimir Kalousek ◽

Ezequiel Petra ◽

...

Keyword(s):

Flow Diverter ◽

Posterior Circulation ◽

Flow Diversion ◽

Anterior Communicating Artery ◽

Anterior Circulation ◽

Low Profile ◽

Specific Subgroup ◽

Flow Diverter Devices ◽

Profile Flow ◽

Incomplete Occlusion

Flow diverter devices have become a routine first-line option for treatment of an increasing population of intracranial aneurysms at many neurovascular centers. Despite the promising results of flow diverter stents on anterior circulation, incomplete occlusion on the presence of fetal posterior circulation has been described on several reports. Here we describe a novel technical alternative to conventional flow diversion approach for this specific subgroup of aneurysms using the low-profile flow diverter, Silk Vista Baby. The device was selectively placed into the fetal type posterior cerebral artery in half-T configuration for the treatment of a posterior communicating aneurysm using a transcirculation approach through the anterior communicating artery. This represents a useful and effective technique and should be considered when encountering the above-described situation.

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