scholarly journals Interaction between Flow Diverter and Parent Artery of Intracranial Aneurysm: A Computational Study

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Wenyu Fu ◽  
Qixiao Xia

To evaluate the influence of deployment strategy on the mechanical interaction between braided stent and parent artery of intracranial aneurysm (the elasticity of the arterial wall is considered), finite-element analyses are carried out by referring to computational models of flow-diverter device and arterial wall. Two implantation strategies are used to virtually implant the braided stent into the ideal intracranial aneurysm model. One is the noncompacted implantation method, and the other is the implantation method of using push-pull technique. During the process of the implantation, the changes of the arterial shape around the aneurysm and the changes of the wall pressure at the contact area between the braided stent and the inner wall of the artery are analyzed. The results indicate that the average contact pressure in the area of low porosity is 57 mmHg using the push-pull technique, and the average contact pressure of the parent artery is 10.45 mmHg using the non-push-pull technique. The diameter of the parent artery at the aneurismal orifice increased about 0.2 mm when using the push-pull technique, so the elasticity of the vessel should be considered in the mechanical analysis of interaction between stent and vessel.

2016 ◽  
Vol 30 (4) ◽  
pp. 467-474
Author(s):  
Marco Zenteno ◽  
Angel Lee ◽  
Jennifer Lorena Herrera Bejarano ◽  
Guru Dutta Satyarthee ◽  
Hernando Raphael Alvis-Miranda ◽  
...  

Abstract The ultimate aims of treatment of the intracranial aneurysms are reconstruction the vessel wall and correcting the hemodynamic disturbance. A flow diverter (FD) is a stent placed inside lumen of the parent artery with aim to blood flow reduction into the aneurysms sac to the extent of almost stagnation leading to gradual onset of progressive thrombosis and neointimal lining of arterial wall remodeling to maintain blood outflow into perforators the side and branches. Flow diverter is considered as an effective treatment for fusiform, wide-necked, large and giant intracranial unruptured aneurysms. However, FD implantation may also be associated with growth and rupture of residual aneurysms. The most frequent complication of endovascular aneurysms management is thromboembolic events and less common are intra and postoperative hemorrhagic aneurysmal rupture. Authors report a case where a lack of operation of the device as illustration is presented to demonstrate the shortcomings of this new type of devices.


2021 ◽  
Author(s):  
Hao-Ming Hsiao ◽  
Ming-Ya Hung ◽  
Tzu-Yun Chou ◽  
Yu-Chieh Cheng ◽  
Li-Han Lin ◽  
...  

Abstract An intracranial aneurysm is a weakened area in the wall of a cerebral artery which causes abnormal localized ballooning of the blood vessel. As an aneurysm grows, it puts pressure on adjacent structures and may eventually rupture, leading to severe complications or even sudden death. The standard treatments for intracranial aneurysms include traditional craniotomy and endovascular coiling. The purpose of these treatments is to stop the blood flow to an aneurysm to reduce the risk of rupture. In recent years, another new device, "flow diverter", has gained popularity. It is placed in the parent artery to divert the blood flow away from the weakened area, isolating aneurysms from normal circulation. Although flow diverter stents have great potential, there remains clinical issues to be resolved. This paper proposes a unique hybrid flow diverter, the first of its kind in the world, for treatment of the intracranial aneurysm. The hybrid flow diverter is designed to have variable mesh densities, with the denser side facing an aneurysm to block the blood flow and the lighter side facing the artery to prevent stenosis. It is deployed in the main cerebral artery next to an aneurysm to divert the blood flow away from the weakened aneurysm. Simulation results showed that the hybrid flow diverter reduced the blood flow into an aneurysm by a whopping 75-95%. The residence time of the blood flow inside an aneurysm was 12.47 times longer with the hybrid flow diverter, which may trigger thrombogenic reaction to fill an aneurysm and thus reduce the risk of rupture.


Author(s):  
Philip Purcell ◽  
Fiona McEvoy ◽  
Stephen Tiernan ◽  
Derek Sweeney ◽  
Seamus Morris

Vertebral compression fractures rank among the most frequent injuries to the musculoskeletal system, with more than 1 million fractures per annum worldwide. The past decade has seen a considerable increase in the utilisation of surgical procedures such as balloon kyphoplasty to treat these injuries. While many kyphoplasty studies have examined the risk of damage to adjacent vertebra after treatment, recent case reports have also emerged to indicate the potential for the treated vertebra itself to re-collapse after surgery. The following study presents a combined experimental and computational study of balloon kyphoplasty which aims to establish a methodology capable of evaluating these cases of vertebral re-collapse. Results from both the experimental tests and computational models showed significant increases in strength and stiffness after treatment, by factors ranging from 1.44 to 1.93, respectively. Fatigue tests on treated specimens showed a 37% drop in the rate of stiffness loss compared to the untreated baseline case. Further analysis of the computational models concluded that inhibited PMMA interdigitation at the interface during kyphoplasty could reverse improvements in strength and stiffness that could otherwise be gained by the treatment.


2021 ◽  
pp. neurintsurg-2021-017469
Author(s):  
Cameron G McDougall ◽  
Orlando Diaz ◽  
Alan Boulos ◽  
Adnan H Siddiqui ◽  
Justin Caplan ◽  
...  

ObjectiveTo evaluate the safety and effectiveness of the Flow Redirection Endoluminal Device (FRED) flow diverter in support of an application for Food and Drug Administration approval in the USA.Methods145 patients were enrolled in a prospective, single-arm multicenter trial. Patients with aneurysms of unfavorable morphology for traditional endovascular therapies (large, wide-necked, fusiform, etc) were included. The trial was designed to demonstrate non-inferiority in both safety and effectiveness, comparing trial results with performance goals (PGs) established from peer-reviewed published literature. The primary safety endpoint was death or major stroke (National Institutes of Health Stroke Scale score ≥4 points) within 30 days of the procedure, or any major ipsilateral stroke or neurological death within the first year. The primary effectiveness endpoint was complete occlusion of the target aneurysm with ≤50% stenosis of the parent artery at 12 months after treatment, and in which an alternative treatment of the target intracranial aneurysm had not been performed.Results145 patients underwent attempted placement of a FRED device, and one or more devices were placed in all 145 patients. 135/145 (93%) had a single device placed. Core laboratory adjudication deemed 106 (73.1%) of the aneurysms large or giant. A safety endpoint was experienced by 9/145 (6.2%) patients, successfully achieving the safety PG of <15%. The effectiveness PG of >46% aneurysm occlusion was also achieved, with the effectiveness endpoint being met in 80/139 (57.6%)ConclusionAs compared with historically derived performance benchmarks, the FRED flow diverter is both safe and effective for the treatment of appropriately selected intracranial aneurysms.Clinical registration numberNCT01801007


2018 ◽  
Vol 118 ◽  
pp. 132-138 ◽  
Author(s):  
Kuntal Kanti Das ◽  
Gagandeep Singh ◽  
Satyadeo Pandey ◽  
Kamlesh Singh Bhaisora ◽  
Awadhesh Jaiswal ◽  
...  

2021 ◽  
pp. neurintsurg-2021-017554.rep
Author(s):  
Giovanni Barchetti ◽  
Loris Di Clemente ◽  
Mauro Mazzetto ◽  
Mariano Zanusso ◽  
Paola Ferrarese ◽  
...  

We report the successful treatment of multiple ruptured fusiform middle cerebral artery (MCA) aneurysms in a 10-month-old girl. This previously healthy infant presented with subarachnoid haemorrhage and was found to have multiple irregular dilatations of the superior division branch of the right MCA. Cerebral angiography was performed and confirmed the presence of multiple fusiform aneurysms of the MCA. After multidisciplinary team discussion, it was decided to treat the aneurysms with endovascular approach, using a flow-diverter. Microsurgical clipping was deemed risky because of the high likelihood of parent artery occlusion and expectant management was also considered inappropriate because of the risk of re-bleeding. Dual antiplatelet therapy was started, and a flow-diverter was successfully delivered in the superior division branch of the right MCA. The post-operative course was uneventful, MRI at 12 months did not show any sign of recurrence and at 3 years of age the patient had a normal neurological examination.


Stroke ◽  
2014 ◽  
Vol 45 (suppl_1) ◽  
Author(s):  
Ajay K Wakhloo ◽  
Pedro Lylyk ◽  
Joost de Vries ◽  
Matthew J Gounis ◽  
Alexandra Biondi ◽  
...  

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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