Overview of Different Flow Diverters and Flow Dynamics

Neurosurgery ◽  
2019 ◽  
Vol 86 (Supplement_1) ◽  
pp. S21-S34 ◽  
Author(s):  
Georgios A Maragkos ◽  
Adam A Dmytriw ◽  
Mohamed M Salem ◽  
Vincent M Tutino ◽  
Hui Meng ◽  
...  
Keyword(s):  
Rapid Evolution ◽  
Evidence Base ◽  
Flow Diverter ◽  
Outcome Data ◽  
Flow Diversion ◽  
Comprehensive Overview ◽  
Flow Diverter Devices ◽  
Technical Specifications ◽  
Flow Diverters

Abstract Over the past decade, flow diverter technology for endocranial aneurysms has seen rapid evolution, with the development of new devices quickly outpacing the clinical evidence base. However, flow diversion has not yet been directly compared to surgical aneurysm clipping or other endovascular procedures. The oldest and most well-studied device is the Pipeline Embolization Device (PED; Medtronic), recently transitioned to the Pipeline Flex (Medtronic), which still has sparse data regarding outcomes. To date, other flow diverting devices have not been shown to outperform the PED, although information comes primarily from retrospective studies with short follow-up, which are not always comparable. Because of this lack of high-quality outcome data, no reliable recommendations can be made for choosing among flow diversion devices yet. Moreover, the decision to proceed with flow diversion should be individualized to each patient. In this work, we wish to provide a comprehensive overview of the technical specifications of all flow diverter devices currently available, accompanied by a succinct description of the evidence base surrounding each device.

scholarly journals Endovascular Treatment of Intracranial Aneurysms in the Flow Diverter Era: Frequency of Use and Results in a Consecutive Series of 550 Treatments in a Single Centre

2014 ◽  
Vol 20 (4) ◽  
pp. 428-435 ◽  
Author(s):  
Willem Jan van Rooij ◽  
Ratna S Bechan ◽  
Jo P. Peluso ◽  
Menno Sluzewski
Keyword(s):  
Intracranial Aneurysms ◽  
Flow Diverter ◽  
Flow Diversion ◽  
Consecutive Series ◽  
Complication Rates ◽  
Parent Vessel ◽  
Vessel Occlusion ◽  
Permanent Neurological Deficit ◽  
Flow Diverters

Flow diverter devices became available in our department in 2009. We considered treatment with flow diverters only in patients with aneurysms not suitable for surgery or conventional endovascular techniques. This paper presents our preliminary experience with flow diverters in a consecutive series of 550 endovascular aneurysm treatments. Between January 2009 and July 2013, 550 endovascular treatments for intracranial aneurysms were performed. Of these, 490 were first-time aneurysm treatments in 464 patients and 61 were additional treatments of previously coiled aneurysms in 51 patients. Endovascular treatments consisted of selective coiling in 445 (80.8%), stent-assisted coiling in 68 (12.4%), balloon-assisted coiling in 13 (2.4%), parent vessel occlusion in 12 (2.2%) and flow diverter treatment in 12 (2.2%). Eleven patients with 12 aneurysms were treated with flow diverters. Two patients had ruptured dissecting aneurysms. One patient with a basilar trunk aneurysm died of acute in stent thrombosis and another patient died of brain stem ischaemia at 32 months follow-up. One patient had ischaemia with permanent neurological deficit. Two aneurysms are still open at up to 30 months follow-up. Flow diversion was used in 2% of all endovascular treatments. Both our own poor results and the high complication rates reported in the literature have converted our initial enthusiasm to apprehension and hesitancy. The safety and efficacy profile of flow diversion should discourage the use of these devices in aneurysms that can be treated with other techniques.

scholarly journals Vertebral artery aneurysms and the risk of cord infarction following spinal artery coverage during flow diversion

2020 ◽  
pp. 1-10
Author(s):  
Adam A. Dmytriw ◽  
Anish Kapadia ◽  
Alejandro Enriquez-Marulanda ◽  
Carmen Parra-Fariñas ◽  
Anna Luisa Kühn ◽  
...  
Keyword(s):  
Vertebral Artery ◽  
Posterior Inferior Cerebellar Artery ◽  
Flow Diverter ◽  
Thromboembolic Complication ◽  
Flow Diversion ◽  
Cerebellar Artery ◽  
Aneurysm Occlusion ◽  
Aneurysm Diameter ◽  
Flow Diverters

OBJECTIVECoverage of the anterior spinal artery (ASA) ostia is a source of considerable consternation regarding flow diversion (FD) in vertebral artery (VA) aneurysms due to cord supply. The authors sought to assess the association between coverage of the ASA, posterior spinal artery (PSA), or lateral spinal artery (LSA) ostia when placing flow diverters in distal VAs and clinical outcomes, with emphasis on cord infarction.METHODSA multicenter retrospective study of 7 institutions in which VA aneurysms were treated with FD between 2011 and 2019 was performed. The authors evaluated the risk of ASA and PSA/LSA occlusion, associated thromboembolic complication, complications overall, aneurysm occlusion status, and functional outcome.RESULTSSixty patients with 63 VA and posterior inferior cerebellar artery aneurysms treated with FD were identified. The median aneurysm diameter was 7 mm and fusiform type was the commonest morphology (42.9%). During a procedure, 1 (61.7%) or 2 (33.3%) flow diverters were placed. Complete occlusion was achieved in 71.9%. Symptomatic thromboembolic complications occurred in 7.4% of cases and intracranial hemorrhage in 10.0% of cases. The ASA and PSA/LSA were identified in 51 (80.9%) and 35 (55.6%) complications and covered by the flow diverter in 29 (56.9%) and 13 (37.1%) of the procedures, respectively. Patency after flow diverter coverage on last follow-up was 89.2% for ASA and 100% for PSA/LSA, not significantly different between covered and noncovered groups (p = 0.5 and p > 0.99, respectively). No complications arose from coverage.CONCLUSIONSFD aneurysm treatment in the posterior circulation with coverage of ASA or PSA/LSA was not associated with higher rates of occlusion of these branches or any instances of cord infarction.

scholarly journals Morphologic and Clinical Outcome of Intracranial Aneurysms after Treatment Using Flow Diverter Devices: Mid-Term Follow-Up

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Anna-Katharina Breu ◽  
Till-Karsten Hauser ◽  
Florian H. Ebner ◽  
Felix Bischof ◽  
Ulrike Ernemann ◽  
...  
Keyword(s):  
Contrast Material ◽  
Flow Diverter ◽  
Neurological Deficits ◽  
Early Improvement ◽  
Cranial Nerve Function ◽  
History Of ◽  
Flow Diverter Devices ◽  
Occlusion Rate ◽  
Flow Diverters

Flow diverters (FDs) are designed for the endovascular treatment of complex intracranial aneurysm configurations. From February 2009 to March 2013 28 patients (22 females, 6 males) were treated with FD; mean age was 57 years. Data, including aneurysm features, clinical presentation, history of previous bleeding, treatment, and follow-up results, are presented. Early postinterventional neurological deficits (transient:n=3/enduring:n=1) appeared in 4/28 patients (14%), and early improvement of neurological symptoms was observed in 7 patients with previous restriction of cranial nerve function. The overall occlusion rate was 20/26 (77%; 59% after 3 months). 77% achieved best results according to O’Kelly-Marotta score grade D with no contrast material filling (70% of those after 3 months). In 4/6 patients who did not achieve grade D, proximal and/or distal stent overlapping ≥5 mm was not guaranteed sufficiently. During follow-up we did not detect any aneurysm recurrence or haemorrhage. In-stent stenosis emerged as the most frequent complication (4/27; 15%) followed by 2 cases of vascular obliteration (AICA/VA). In conclusion endovascular reconstruction using a FD represents a modern and effective treatment in those aneurysms that are not suitable for conventional interventional or surgical treatment. The appearance of severe complications was rare.

scholarly journals Re-treatment of residual aneurysms after flow diversion: An experimental study

2018 ◽  
Vol 31 (3) ◽  
pp. 270-279 ◽  
Author(s):  
Robert Fahed ◽  
Tim E Darsaut ◽  
Marc Kotowski ◽  
Igor Salazkin ◽  
Jean Raymond
Keyword(s):  
Flow Diverter ◽  
Artery Occlusion ◽  
Flow Diversion ◽  
Embolic Agent ◽  
Parent Artery ◽  
Arterial Lumen ◽  
Parent Artery Occlusion ◽  
Liquid Embolic ◽  
Liquid Embolic Agent ◽  
Flow Diverters

Aim Flow diverters are increasingly used to treat aneurysms, but treatment is not always effective. The management of aneurysms that fail to occlude following flow diversion is problematic. We aimed to reproduce failures in an animal model and study re-treatment with additional flow diverters alone or with flow diverters and liquid embolic agent. Material and methods Twenty wide-necked aneurysms were created at the carotid-lingual bifurcation in 10 dogs, and were treated with flow diverters 4–6 weeks later. Follow-up angiography was performed at three months. Suitable residual aneurysms were randomly allocated: re-treatment with flow diverters alone ( n = 6), or with the injection of liquid embolic between two layers of flow diverters ( n = 4) or no re-treatment ( n = 2). Angiography was repeated three months later, followed by euthanasia, photography and pathology. Results Patent wide-necked aneurysms were produced in 17/20 attempts (85%); three months after flow diversion there were 15/17 (88%) residual aneurysms. In three cases, re-treatment was not possible because the flow diverter had prolapsed into the aneurysm, leaving 12 aneurysms to study. Re-treated aneurysms showed improved angiographic results at six months (median score of 2; P = 0.03), but residual aneurysms were present in all cases. Parent artery occlusion occurred in two aneurysms treated with flow diverter plus liquid embolic. At pathology, aneurysms were only partially filled with thrombus; leaks through the flow diverters were found in the neointima connecting the arterial lumen to residual aneurysms. Conclusion Re-treatment of residual flow-diverted experimental aneurysms with additional flow diverters did not lead to aneurysm occlusion.

Successful management of bilateral internal carotid artery fusiform giant aneurysms in a patient with intimal fibroplasia using multiple flow diverters: With long-term imaging follow up

2021 ◽  
pp. 159101992110491
Author(s):  
Jieun Roh ◽  
Seung Kug Baik ◽  
Jeong A Yeom ◽  
Joo-Young Na ◽  
Sang-Won Lee
Keyword(s):  
Carotid Artery ◽  
Internal Carotid Artery ◽  
Internal Carotid ◽  
Flow Diverter ◽  
Giant Aneurysms ◽  
The Past ◽  
Effective Treatment Modality ◽  
Flow Diverters

The authors report a rare case of sequentially developed bilateral internal carotid artery (ICA) fusiform giant aneurysms in a patient with pathologically confirmed intimal fibroplasia. Both ICA fusiform aneurysms were treated with multiple flow diverter insertion and were well-managed over the past 5.5 years of follow-up. The development of aneurysms in this rare disease entity appears to be a lifelong process based on the authors’ observations in serial angiographic follow-up studies. Reconstruction therapy using flow-diverting stents in this unique condition may be a safe and effective treatment modality.

Abstract 1122‐000152: Flow Diverter Use in Acutely Presented Dissecting Aneurysms, 2 Years Follow Up of 53 Cases

2021 ◽  
Vol 1 (S1) ◽  
Author(s):  
Ossama Y Mansour ◽  
Aser Goma
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Clinical Outcome ◽  
Flow Diverter ◽  
Parent Artery ◽  
Modified Rankin Scale ◽  
Alternative Treatment Option ◽  
Increased Risk ◽  
Flow Diverters ◽  
Dissecting Aneurysms

Introduction : Acute dissecting aneurysms are among the uncommon causes of subarachnoid hemorrhage. Established endovascular treatment options include parent artery occlusion and stent‐assisted coiling, but appear to be associated with an increased risk of ischemic stroke. reconstruction of the vessels with flow diverters is an alternative therapeutic option. Methods : This is a retrospective analysis of 53 consecutive acutely ruptured dissecting aneurysms treated with flow diverters. The primary end point was favorable aneurysm occlusion, defined as OKM C1‐3 and D . Secondary end points were procedure‐related complications and clinical outcome. Results : 23 aneurysms (43.4%%) arose from the intradural portion of the vertebral artery, 10 (18.8%) were located on the posterior inferior cerebellar artery and 3 (5.6%) posterior cerebral artery, 7 (13.2%) MCA, (18.8%) ICA . 45 aneurysms presented by SAH while 8 presented by Ischemic manifestation. Flow diverter placement was technically successful in all cases . immediate postoperative rerupture occurred in two case (3.7%), thromboembolic complications in 3 cases (5.7%). Median clinical follow‐up was 640 days and median angiographic follow‐up was 690 days. ten patients (18.9%) with poor‐grade subarachnoid hemorrhage died in the acute phase. Favorable clinical outcome (modified Rankin scale ≤2) was observed in 27 of 53 patients (51%) and a moderate outcome (modified Rankin scale 3/4) was observed in 12 of 53 patients (22.6%). All aneurysms showed complete occlusion at follow‐up. Conclusions : Flow diverters might be a feasible, alternative treatment option for acutely symptomatic dissecting aneurysms and may effectively prevent rebleeding in ruptured aneurysms.

scholarly journals Application of flow diverters in the treatment of aneurysms in the internal carotid artery bifurcation region

2020 ◽  
Vol 33 (4) ◽  
pp. 297-305
Author(s):  
Mostafa Mahmoud ◽  
Ahmed Farag ◽  
Mostafa Farid ◽  
Ahmed Elserwi ◽  
Amr Abdelsamad ◽  
...  
Keyword(s):  
Carotid Artery ◽  
Internal Carotid Artery ◽  
Internal Carotid ◽  
Case Reports ◽  
Therapeutic Option ◽  
Case Series ◽  
Flow Diversion ◽  
Occlusion Rate ◽  
Flow Diverters

Introduction The treatment of aneurysms in the internal carotid bifurcation region (ICABR), including aneurysms of the true internal carotid artery (ICA) terminus, those inclined on the proximal A1 or M1 segments or at the most distal pre-bifurcation (ICA) segment, is often challenging in microsurgical clipping and endovascular surgery. Few reports had discussed flow diversion as a therapeutic option for this group. Methods This was a retrospective study analysing flow diversion in treating ICABR aneurysms. Seven patients harbouring eight aneurysms in the ICABR were treated with flow diversion. Five aneurysms were inclined on the proximal A1 segment, and three were located at the most distal pre-bifurcation segment. Patients’ demographics, presentation, procedure technical description, angiographic and clinical follow-up were recorded. PubMed and Ovid MEDLINE were also reviewed for articles published in English, including case series or case reports, for ICABR aneurysms treated with flow diverters. Results All patients except one underwent angiographic follow-up. The Karman–Byrne occlusion scale was used to determine the occlusion rate. All six patients with documented angiographic follow-up had a class IV occlusion score. No permanent or transient neurological or non-neurological complications were encountered in this study. Conclusion Treating ICABR aneurysms using flow diversion is feasible, with a promising angiographic occlusion rate. Further studies are needed to analyse long-term clinical and angiographic results.

Transient in-stent stenosis: a common finding after flow diverter implantation

2018 ◽  
Vol 11 (2) ◽  
pp. 196-199 ◽  
Author(s):  
Ruben Mühl-Benninghaus ◽  
Alena Haußmann ◽  
Andreas Simgen ◽  
Toshiki Tomori ◽  
Wolfgang Reith ◽  
...  
Keyword(s):  
Flow Diverter ◽  
Common Finding ◽  
Short Term ◽  
Long Term Follow Up ◽  
Incomplete Occlusion ◽  
Flow Diverters ◽  
Stent Stenosis ◽  
Related Mortality

Background and purposeIn recent years, implantation of flow diverters has emerged as an option for the endovascular treatment of intracranial aneurysms. One complication of treatment with flow diverters is the occurrence of in-stent stenosis, which has been reported to be partially reversible. The purpose of our study was to assess the incidence and dynamics of in-stent stenosis on angiographic short term and long term follow-up after treatment with flow diverters.MethodsA retrospective review of our prospectively maintained database identified all patients with intracranial internal carotid artery (ICA) aneurysms treated by flow diverters at our institution between 2014 and 2017. Clinical charts, procedural data, and angiographic results were reviewed.Results18 patients were included. The mean short term follow-up was 92±19 days and mean long term follow-up was 449±120 days after treatment. No neurologic complications were observed. There was no procedure related mortality. Long term angiographic results showed complete occlusion in 83.3%, neck remnants in 11.1%, and incomplete occlusion in 5.5% of cases. In-stent stenosis was observed in all cases. Mean stenosis improved significantly from 30% on short term follow-up to 12% on long-term follow-up (P<0.0001).ConclusionIn-stent stenosis is a common finding on short term follow-up after the treatment with flow diverters but improves over time.

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

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.

scholarly journals The implications of magnetic resonance angiography artifacts caused by different types of intracranial flow diverters

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Batur Halitcan ◽  
Sayin Bige ◽  
Balci Sinan ◽  
Akmangit Ilkay ◽  
Daglioglu Ergun ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Angiography ◽  
Predictive Value ◽  
Diagnostic Yield ◽  
Flow Diverter ◽  
Parent Artery ◽  
Perfect Agreement ◽  
Tof Mra ◽  
Flow Diverters

Abstract Background Serial cerebral angiographic imaging is necessary to ensure cerebral aneurysm occlusion after flow diverter placement. Time-of-flight (TOF)-magnetic resonance angiography (MRA) is used for this purpose due to its lack of radiation, contrast media and complications. The comparative diagnostic yield of TOF-MRA for different flow diverters has not been previously analyzed. Purpose To evaluate the diagnostic accuracy of TOF-MRA in cerebral aneurysms treated w divertersith different flow diverters. Materials and Methods Flow-diverted patients whose cerebral follow-up MRA and digital subtraction angiograms (DSA) were obtained within 6 weeks were retrospectively identified. The DSA (as gold standard) and MRA images of these patients were compared by two readers (blinded to both patient data and endovascular procedure data) for residual aneurysms and the status of the parent artery for each type of flow diverter. In a second group of patients, magnetic susceptibility artifacts were manually measured and compared for different FDs. Results Seventy-six patients (85 aneurysms) were included in group one, and 86 patients (95 aneurysms) were included in group 2. TOF-MRA and DSA showed almost perfect agreement for residual aneurysms (κ = 0.88, p < 0.001) (positive predictive value (PPV) = 1.00, specificity = 1.00, negative predictive value (NPV) = 0.89, sensitivity = 0.89). Intermodality agreement (κ = 0.97 vs. κ = 0.74, p < 0.005) and sensitivity (0.97 vs. 0.77, NPV: 0.96 vs. 0.77) were highest with nitinol stents. MRA and DSA showed no agreement for occluded or stenotic parent vessels (κ = 0.13, p = 0.015, specificity = 0.44, NPV = 1.00, sensitivity = 1.00). Specificity was lower in chromium-cobalt based FDs than in nitinol devices (specificity = 0.08 vs. 0.60). Chromium-cobalt stents generated the largest artifacts (p < 0.005). The size of the device-related artifact, in millimeters, increased in respective order, for the Silk, Derivo, Pipeline and Surpass devices. Conclusion Unlike DSA, TOF-MRA is susceptible to dissimilarities between flow diverters. MRA is not well-suited for research studies comparing different flow diverters. Nitinol FDs appear to be advantageous for TOF-MRA follow-up so as not to miss small aneurysm remnants or clinically relevant parent artery stenosis.

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