Association of Wall Stress of Human Intracranial Saccular Aneurysm With Coil Packing Density After Coil Embolization

Author(s):  
Joseph E. Pichamuthu ◽  
Alkiviadis Tsamis ◽  
Brian T. Jankowitz ◽  
David A. Vorp

Coil embolization has become a widely accepted endovascular procedure for intracranial aneurysms, as an alternative to surgical clipping [1,2]. This procedure involves treating an aneurysm from the inside out, whereby metallic coils are placed into the aneurysm to induce thrombosis of the lumen and eliminate the risk of rupture and hemorrhage. Successful endosaccular packing mainly depends on the morphological features and size of the aneurysm, and the relationship of the aneurysm to the cerebral arteries.

Neurosurgery ◽  
2002 ◽  
Vol 50 (3) ◽  
pp. 476-485 ◽  
Author(s):  
Hiro Kiyosue ◽  
Mika Okahara ◽  
Shuichi Tanoue ◽  
Takaharu Nakamura ◽  
Hirofumi Nagatomi ◽  
...  

Abstract OBJECTIVE: Detection of a small residual lumen after coil embolization is often difficult because of the coil mass and the overlap of the cerebral arteries. The purpose of this study was to assess the usefulness of virtual endoscopic (VE) analysis of three-dimensional digital subtraction angiographic (DSA) images for evaluation of aneurysmal occlusion immediately after the procedure. METHODS: Twenty-seven intracranial aneurysms were treated with coil embolization using a three-dimensional DSA system. Biplane and rotational DSA scanning was performed before and immediately after the procedures. VE images were obtained at a separate workstation, after transfer of the rotational images. Two-dimensional (2D) DSA images and VE images obtained after the procedure were assessed with respect to aneurysmal occlusion. Morphological outcomes and other factors, including location, size, volumetric ratio (coil volume/aneurysm volume), and residual sites, were also evaluated. RESULTS: Seven aneurysms were evaluated as complete occlusion (CO) on both 2D DSA images and VE images. Twelve aneurysms exhibited residual lumina on both 2D DSA images and VE images. Five aneurysms were evaluated as CO on 2D DSA images and as incomplete occlusion on VE images. There were no recurrences among the aneurysms that were evaluated as CO on VE images. Two of five aneurysms that were evaluated as CO on 2D DSA images and as incomplete occlusion on VE images demonstrated regrowth in follow-up examinations. Residual sites and volumetric ratios were correlated with aneurysmal regrowth. CONCLUSION: VE imaging can demonstrate a residual lumen more frequently than can 2D DSA imaging and is useful for evaluating aneurysmal occlusion after coil embolization.


2018 ◽  
Vol 129 (6) ◽  
pp. 1492-1498 ◽  
Author(s):  
Masaomi Koyanagi ◽  
Akira Ishii ◽  
Hirotoshi Imamura ◽  
Tetsu Satow ◽  
Kazumichi Yoshida ◽  
...  

OBJECTIVELong-term follow-up results of the treatment of unruptured intracranial aneurysms (UIAs) by means of coil embolization remain unclear. The aim of this study was to analyze the frequency of rupture, retreatment, stroke, and death in patients with coiled UIAs who were followed for up to 20 years at multiple stroke centers.METHODSThe authors retrospectively analyzed data from cases in which patients underwent coil embolization between 1995 and 2004 at 4 stroke centers. In collecting the late (≥ 1 year) follow-up data, postal questionnaires were used to assess whether patients had experienced rupture or retreatment of a coiled aneurysm or any stroke or had died.RESULTSOverall, 184 patients with 188 UIAs were included. The median follow-up period was 12 years (interquartile range 11–13 years, maximum 20 years). A total of 152 UIAs (81%) were followed for more than 10 years. The incidence of rupture was 2 in 2122 aneurysm-years (annual rupture rate 0.09%). Nine of the 188 patients with coiled UIAs (4.8%) underwent additional treatment. In 5 of these 9 cases, the first retreatment was performed more than 5 years after the initial treatment. Large aneurysms were significantly more likely to require retreatment. Nine strokes occurred over the 2122 aneurysm-years. Seventeen patients died in this cohort.CONCLUSIONSThis study demonstrates a low risk of rupture of coiled UIAs with long-term follow-up periods of up to 20 years. This suggests that coiling of UIAs could prevent rupture for a long period of time. However, large aneurysms might need to be followed for a longer time.


Author(s):  
S. L. Cornejo ◽  
J. F. Rodriguez ◽  
A. A. Valencia ◽  
A. M. Guzman ◽  
E. A. Finol

There are several biomechanical factors involved in the formation, growth, remodeling, and eventual rupture of intracranial aneurysms. In particular, hemodynamic forces have a decisive role in the biomechanical environment of the aneurysmal cerebral vasculature. Most of the previous studies on vascular mechanics assessment of intracranial aneurysms are based on idealized geometries, where it has been suggested [1] that it is highly unlikely that saccular aneurysms expand due to a limit point instability. In addition, it has been reported [2] that some saccular aneurysms with non-spherical initial shape tend to become spherical when subjected to uniform pressure, because a spherical geometry is optimal to resist the pressure load, yielding a homogenous wall stress. In the present work, we present a comparison between anisotropic and isotropic constitutive models, which allows us to analyze the biomechanics of patient-specific cerebral aneurysmal arteries subjected to flow-induced pulsatile pressure. The results describe the effects of material anisotropy in the resulting wall mechanics of the intracranial vasculature geometries.


2008 ◽  
Vol 14 (2_suppl) ◽  
pp. 49-52 ◽  
Author(s):  
Tzu-Hsien Yang ◽  
Ho-Fai Wong ◽  
Ming-Shiang Yang ◽  
Chang-Hsien Ou ◽  
Tzu-Lung Ho

Endovascular treatment of intracranial aneurysms by coiling has become an accepted alternative to surgical clipping 1. In cases of wide-necked and sidewall aneurysms, selective embolization is difficult because of the risk of coil protrusion into the parent vessel. The use of three-dimensional coils, stents 2, and balloon remodeling have all aided the attempt to adequately manage such lesions. However, compared with sidewall aneurysms, bifurcation aneurysms are more challenging from an endovascular standpoint. Because of their specific anatomy and hemodynamics, the tendency to recur and rerupture is higher. Several authors have reported successful treatment of these complex and wide-necked bifurcation aneurysms by using Y-configured dual stent-assisted coil embolization 3,4, the double microcatheter technique 5, a more compliant balloon remodeling technique6, the TriSpan neck-bridge device7, or the waffle cone technique8. We describe two cases of wide-necked bifurcation aneurysms in which the waffle cone technique was used for coil embolization. The waffle cone technique was first described in 2006; however, the small number of published cases and the lack of follow-up prevent one from assessing this technique's durability and the probability of recanalization. We report the cases of two patients harboring unruptured wide-necked bifurcation aneurysms that were treated and followed-up for six months.


Neurosurgery ◽  
2003 ◽  
Vol 52 (6) ◽  
pp. 1280-1290 ◽  
Author(s):  
Christian Raftopoulos ◽  
Pierre Goffette ◽  
Geraldo Vaz ◽  
Najib Ramzi ◽  
Jean-Louis Scholtes ◽  
...  

Abstract OBJECTIVE Recent reports in the literature have described a significant discrepancy in adverse outcomes between coil embolization (CE; 10%) and surgical clipping (SC; 25%) for the management of unruptured intracranial aneurysms (UIA). This discrepancy led us to analyze our experience. METHODS In 1996, we designed a prospective study of patients with UIA in which CE was considered the treatment of choice and was performed if the interventional neuroradiologists deemed the aneurysm's fundus-to-neck ratio accessible for CE. SC was performed only if complete CE was unlikely to be achieved or in patients in whom CE already had failed. RESULTS CE was performed in 38 patients with at least one UIA (41 UIAs, 83% in the anterior circulation). SC was performed in 39 patients with at least one UIA unsuitable for CE (59 UIAs, including 6 after failed CE, 96.5% in the anterior circulation). For CE, the total obliteration rate was 56.1%, the subtotal was 14.6%, and CE failed in 29.3%. There were transient complications in 10% of the cases and permanent complications in 7.5%. Of the 12 failed CE procedures, 7 (58%) were performed for middle cerebral artery aneurysms. For SC, the total obliteration rate was 93.2%, the subtotal was 1.7%, and SC failed (wrapping) in 5.1%. There were transient complications in 16.3% of the patients and permanent complications in 1.7%. The success rate for CE was similar to that for SC only when CE was used for aneurysms with a fundus-to-neck ratio of at least 2.5. CONCLUSION SC can produce better results than CE in patients with UIA of the anterior circulation. CE as a first-line treatment should be reserved for patients with UIAs with a fundus-to-neck ratio of 2.5 or greater.


2020 ◽  
Vol 1 (4) ◽  
Author(s):  
Kashif Majeed ◽  
Srikanth R Boddu ◽  
Joseph Carnevale ◽  
Elif Ezgi Cenberlitas ◽  
Nicholas Williams ◽  
...  

Abstract BACKGROUND To stratify the risk of aneurysmal rupture, size remains the primary criterion as proposed by 2 ISUIA (International Study of Unruptured Intracranial Aneurysms) trials that recommend the observation of ≤7 mm aneurysms because of their low propensity to rupture. These recommendations are controversial, given the severe outcomes following hemorrhage. OBJECTIVE To retrospectively assess whether size correlates with aneurysmal rupture, and to analyze outcomes of endovascular and microsurgical procedures. METHODS All aneurysms presenting between 2016 and 2019 were reviewed. Age, gender, comorbidities, ruptured status, modes of treatment, and their outcomes were noted. Regression analysis was performed to correlate size with rupture. The type of intervention was based on clinical and aneurysmal characteristics and the likelihood of obliteration. RESULTS Of the 668 aneurysms, 116 had ruptured. In size groups 0 to 6 mm,  7 to 12 mm,  13 to 18 mm,  18 to 24 mm, and giant, the ruptured aneurysms were 60.3%, 30.2%, 1.7%, 0.9%, and 6.9%, respectively. The majority (423) were managed endovascularly, of which 84 (19.9%) were ruptured. A total of 97 (14.5%) underwent clipping, of which 31 were ruptured. The mean modified Rankin Scale for both treated groups was zero. One death in each group and a single brainstem stroke in the coiled group were noted. A total of 139 were followed, of which none had ruptured. The mean modified Raymond-Roy classification for endovascular therapy was 1.1, with 380 completely occluded; 15 had a score of 2, and 28 of score 3. CONCLUSION The ruptured aneurysms were mostly smaller than reported previously. Surgical clipping was at equipoise with endovascular treatments. Further studies to correlate aneurysmal characteristics to the risk of rupture are needed.


Author(s):  
Jishan Luo ◽  
Robert Kunkel ◽  
Jingyu Wang ◽  
Bradley N. Bohnstedt ◽  
Mrinal Saha ◽  
...  

Abstract This paper presents the novel development of highly porous carbon nanotube (CNT)/shape memory polymer (SMP) nanocomposites for potential endovascular treatment of intracranial aneurysms (ICAs). Intracranial aneurysm is a cerebrovascular disorder that can significantly weaken the wall of a brain artery, resulting in a localized dilation of the blood vessel with risk of rupture and subarachnoid bleeding. Current therapeutic options include surgical clipping and endovascular coil embolization. Clipping of intracranial aneurysms is invasive, and, therefore, it has gradually been replaced by non-invasive endovascular embolization. Recent studies have shown that aneurysmal recanalization and incomplete occlusion are still emerging clinical challenges in endovascular coil embolization. Therefore, there is an urgent need to develop new medical devices and surgical procedure to treat intracranial aneurysms with improved long-term outcomes. CNT/SMP nanocomposites are fabricated by directly coating CNTs on sugar particles before fabricating the sugar template for porous nanocomposites. Pristine SMP prepolymer is infiltrated into the pores of sugar template. All the sugar is dissolved in water after the fully curing of PDMS, resulting in SMP based nanocomposites with well dispersed CNTs. The porous nanocomposites are characterized to identify key parameters, such as electrical resistivity and shape memory capability. A resistive-heating mechanism is developed to trigger shape recovery of the nanocomposites. The results of this work will lay a solid foundation for our subsequent development of new personalized biomedical devices to treat ICAs using a catheter-based endovascular embolization procedure.


Populism ◽  
2020 ◽  
Vol 3 (1) ◽  
pp. 121-139
Author(s):  
Tuukka Ylä-Anttila

Abstract This paper assesses the significance of social media for the Finns Party and the related anti-immigration movement from 2007 to the present day, in light of theories on the relationship of populism and social media. These include people-centrism, disenfranchisement, homophily, the attention economy, media elitism, and (lack of) communicative resources. Tracing the historical trajectory of the Finnish anti-immigration movement and the Finns Party, I argue that the Finnish case is an example of a movement being born online and using social media to build a political identity and strategically gain influence through a party, eventually transforming it from the inside out—rather than the party strategically using social media for its purposes, as is sometimes assumed in party-centric literature. While acknowledging the continued importance of parties, research on contemporary populist movements must take into account the political engagement of citizens facilitated by online media.


2020 ◽  
Vol 10 (2) ◽  
pp. 97-103
Author(s):  
Salsalina Salsalina Yuniarty G ◽  
Triswanti Triswanti

The background: Rupture the perineum is ripping was born. Ripping perineum occur in nearly all births, and it is not uncommon for delivery next. Ripping it can be prevented and reduced by keeping and you will pass the flanks by the head of the fetus quickly.Based on indonesia ' s demographic health survey (SDKI) in 2007, maternal mortality rate in the country reached 248 / 100,000 of life. The purpose : Prove the existence of the relation of parity and weight infants born with the rupture of the perineum in BPM Ai Arianti 2018..The methods : Methods used analytic with the approach of cross sectional.The sample collection technique by using techniques of sampling is a total of commentary on the number of deliveries totaled 40 people mother . Data collection in this research is fill a sheet observation.The result : The results of research with the use the chi square showed p-value based on the relationship of parity with the genesis of rupture the perineum of p-value 0,008 and because of pvalue 0,008 <( 0.05 ), then there is rejected meaning of this relationship parity with the rupture of the perineum, relationship based on weight infants born with the incident because of rupture of the perineum of p-value 0,005 and because of p-value 0,116> ( 0.05 ), and Ho no accepted which means there is a weight infants born with the rupture of the perineum in the BPM Ai Arianti 2018. The conclusion: there is a relationship parity and weight infants born with rupture of the perineum in the BPM Ai Arianti 2018. Advice: Expected for pregnant women to growing awareness to do gymnastics pregnant regularly can train to the perineum muscles during childbirth dan teaching how to gymnastics pregnant do the best, so it can reduce the risk of rupture of the perineum. And for the BPM Ai Ariant in the hope more can increase vigilance in doing help childbirth thus reducing the rupture of the perineum in the BPM.


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