Packing Density Necessary to Reach a High Complete Occlusion Rate in Circumferential Unruptured Intracranial Aneurysms Treated with Stent-Assisted Coil Embolization

Abstract BackgroundWe compared the treatment of small unruptured intracranial aneurysms (UIAs) with flow diverter and LVIS assisted coiling to determine the effects of hemodynamic changes caused by different stent and coil packing in endovascular treatment.MethodsFifty-one UIAs in 51 patients treated with pipeline embolization device (PED) were included in this study, and defined as the PED group. We matched controls 1:1 and enrolled 51 UIAs who treated with LVIS stent, which defined as the LVIS group. Computational fluid dynamics were performed to assess hemodynamic alterations between PED and LVIS. Clinical analysis was also performed between these two groups after the match.ResultsThere was no difference in procedural complications between two groups (P=0.558). At the first angiographic follow-up, the complete occlusion rate was significantly higher in the LVIS group compared with that in the PED group (98.0% vs 82.4%, P = 0.027). However, during the further angiographic follow-up, the complete occlusion rate in PED group achieved 100%, which was higher than that in LVIS group (98.0%). Compared with the LVIS group after treatment, cases in PED group showed a higher value of velocity in the aneurysm (0.03 ± 0.09 vs 0.01 ± 0.01, P=0.037) and WSS on the aneurysm (2.32 ± 5.40 vs 0.33 ± 0.47, P=0.011). Consequently, the reduction ratios of these two parameters were also showed statistical differences. These parameters in LVIS group showed much higher reduction ratios. However, the reduction ratio of the velocity on the neck plane was comparable between two groups. ConclusionsBoth LVIS and PED were safe and effective for the treatment of small UIAs. However, LVIS-assisted coiling produced greater hemodynamic alterations in the aneurysm sac compared with PED. The hemodynamics in the aneurysm neck may be a key factor for aneurysm outcome.

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Hemodynamic analysis for endovascular treatment in small unruptured intracranial aneurysms: a matched comparison study of flow diverter versus LVIS

Chinese Neurosurgical Journal ◽

10.1186/s41016-021-00266-w ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Jian Liu ◽

Wenqiang Li ◽

Yisen Zhang ◽

Kun Wang ◽

Xinjian Yang ◽

...

Keyword(s):

Endovascular Treatment ◽

Intracranial Aneurysms ◽

Flow Diverter ◽

Clinical Analysis ◽

Complete Occlusion ◽

Aneurysm Neck ◽

Unruptured Intracranial Aneurysms ◽

Occlusion Rate ◽

Two Parameters

Abstract Background We compared the treatment of small unruptured intracranial aneurysms (UIAs) with flow diverter and LVIS-assisted coiling to determine the effects of hemodynamic changes caused by different stent and coil packing in endovascular treatment. Methods Fifty-one UIAs in 51 patients treated with pipeline embolization device (PED) were included in this study and defined as the PED group. We matched controls 1:1 and enrolled 51 UIAs who were treated with LVIS stent, which were defined as the LVIS group. Computational fluid dynamics were performed to assess hemodynamic alterations between PED and LVIS. Clinical analysis was also performed between these two groups after the match. Results There was no difference in procedural complications between the two groups (P = 0.558). At the first angiographic follow-up, the complete occlusion rate was significantly higher in the LVIS group compared with that in the PED group (98.0% vs. 82.4%, P = 0.027). However, during the further angiographic follow-up, the complete occlusion rate in the PED group achieved 100%, which was higher than that in the LVIS group (98.0%). Compared with the LVIS group after treatment, cases in the PED group showed a higher value of velocity in the aneurysm (0.03 ± 0.09 vs. 0.01 ± 0.01, P = 0.037) and WSS on the aneurysm (2.32 ± 5.40 vs. 0.33 ± 0.47, P = 0.011). Consequently, the reduction ratios of these two parameters also showed statistical differences. These parameters in the LVIS group showed much higher reduction ratios. However, the reduction ratio of the velocity on the neck plane was comparable between two groups. Conclusions Both LVIS and PED were safe and effective for the treatment of small UIAs. However, LVIS-assisted coiling produced greater hemodynamic alterations in the aneurysm sac compared with PED. The hemodynamics in the aneurysm neck may be a key factor for aneurysm outcome.

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Evaluation of the Accero Stent for Stent-Assisted Coiling of Unruptured Wide-Necked Intracranial Aneurysm Treatment with Short-Term Follow-Up

Journal of Clinical Medicine ◽

10.3390/jcm9092808 ◽

2020 ◽

Vol 9 (9) ◽

pp. 2808

Author(s):

Wojciech Poncyljusz ◽

Kinga Kubiak ◽

Leszek Sagan ◽

Bartosz Limanówka ◽

Katarzyna Kołaczyk

Keyword(s):

Subarachnoid Hemorrhage ◽

Intracranial Aneurysms ◽

Clinical Results ◽

Class I ◽

Unruptured Aneurysms ◽

Patient Demographics ◽

Stent Deformation ◽

Unruptured Intracranial Aneurysms ◽

Occlusion Rate

Background: Stent-assisted coiling is an effective method of treating intracranial aneurysms. The aim of the study was to assess the safety and efficacy of the new Accero stent for the treatment of intracranial aneurysms. Materials and Methods: It was a retrospective, single-center study. Eighteen unruptured intracranial aneurysms were treated using the stent-assisted coiling method with the Accero stent. Patient demographics, aneurysm characteristics, procedural parameters, grade of occlusion, complications, and clinical results were analyzed. Follow-up magnetic resonance (MR) was performed 6 months after intervention. Results: Seventeen patients with 18 incidental unruptured aneurysms were electively treated with coiling and the Accero stent. The aneurysms were located on internal carotid artery (ICA), middle cerebral artery (MCA) and basilar artery (BA). All stents were deployed successfully. Immediate complete occlusion rate Raymond-Roy occlusion classification (RROC) class I was achieved in 13 cases and class II in 4 cases. Complications occurred in 2/17 treatments and included guidewire stent perforation with subarachnoid hemorrhage (SAH) and stent deformation. Vascular spasm in the subarachnoid hemorrhage (SAH) patient subsided before discharge. Ninety days after intervention, the modified Rankin Scale (mRS) value was 0. RROC class I was observed in 88.23% of cases in follow-up. Conclusion: The Accero stent provides excellent support for coil mass. It constitutes an efficacious device with good initial occlusion rate for treating wide-necked unruptured intracranial aneurysms.

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Porous Media Computational Fluid Dynamics and the Role of the First Coil in the Embolization of Ruptured Intracranial Aneurysms

Journal of Clinical Medicine ◽

10.3390/jcm10071348 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1348

Author(s):

Karol Wiśniewski ◽

Bartłomiej Tomasik ◽

Zbigniew Tyfa ◽

Piotr Reorowicz ◽

Ernest Bobeff ◽

...

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Porous Media ◽

Packing Density ◽

Coil Embolization ◽

Intracranial Aneurysms ◽

Patient Specific ◽

Computational Fluid Dynamics Analysis ◽

Ruptured Intracranial Aneurysms ◽

Statistical Results

Background: The objective of our project was to identify a late recanalization predictor in ruptured intracranial aneurysms treated with coil embolization. This goal was achieved by means of a statistical analysis followed by a computational fluid dynamics (CFD) with porous media modelling approach. Porous media CFD simulated the hemodynamics within the aneurysmal dome after coiling. Methods: Firstly, a retrospective single center analysis of 66 aneurysmal subarachnoid hemorrhage patients was conducted. The authors assessed morphometric parameters, packing density, first coil volume packing density (1st VPD) and recanalization rate on digital subtraction angiograms (DSA). The effectiveness of initial endovascular treatment was visually determined using the modified Raymond–Roy classification directly after the embolization and in a 6- and 12-month follow-up DSA. In the next step, a comparison between porous media CFD analyses and our statistical results was performed. A geometry used during numerical simulations based on a patient-specific anatomy, where the aneurysm dome was modelled as a separate, porous domain. To evaluate hemodynamic changes, CFD was utilized for a control case (without any porosity) and for a wide range of porosities that resembled 1–30% of VPD. Numerical analyses were performed in Ansys CFX solver. Results: A multivariate analysis showed that 1st VPD affected the late recanalization rate (p < 0.001). Its value was significantly greater in all patients without recanalization (p < 0.001). Receiver operating characteristic curves governed by the univariate analysis showed that the model for late recanalization prediction based on 1st VPD (AUC 0.94 (95%CI: 0.86–1.00) is the most important predictor of late recanalization (p < 0.001). A cut-off point of 10.56% (sensitivity—0.722; specificity—0.979) was confirmed as optimal in a computational fluid dynamics analysis. The CFD results indicate that pressure at the aneurysm wall and residual flow volume (blood volume with mean fluid velocity > 0.01 m/s) within the aneurysmal dome tended to asymptotically decrease when VPD exceeded 10%. Conclusions: High 1st VPD decreases the late recanalization rate in ruptured intracranial aneurysms treated with coil embolization (according to our statistical results > 10.56%). We present an easy intraoperatively calculable predictor which has the potential to be used in clinical practice as a tip to improve clinical outcomes.

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Outcomes following aneurysmal coil embolization with intentionally shortened low-profile visible intraluminal support stent deployment

The Neuroradiology Journal ◽

10.1177/19714009211026925 ◽

2021 ◽

pp. 197140092110269

Author(s):

Kenji Yatomi ◽

Yumiko Mitome-Mishima ◽

Takashi Fujii ◽

Kohsuke Teranishi ◽

Hidenori Oishi ◽

...

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Coil Embolization ◽

Intracranial Aneurysms ◽

Perioperative Complications ◽

Flow Diversion ◽

Stent Deployment ◽

Coverage Ratio ◽

Low Profile ◽

Unruptured Intracranial Aneurysms

Purpose Among all stents available for neuroendovascular therapy, the low-profile visible intraluminal support stent bears the highest metal coverage ratio. We deployed a low-profile visible intraluminal support stent with a delivery wire or/and microcatheter system push action to shorten the low-profile visible intraluminal support stent and thus achieve a flow diversion effect. We report our single-institution experience with the use of low-profile visible intraluminal support stents for intentionally shortened deployment (shortening group) and non-shortened deployment (non-shortening group) for unruptured intracranial aneurysms. Methods We retrospectively reviewed the medical records of 130 patients with 131 intracranial aneurysms who were treated with low-profile visible intraluminal support stent-assisted coil embolization from February 2016–January 2019. All perioperative complications were noted. Every 6 months, we re-examined the patients with cerebral angiography or magnetic resonance angiography. The outcomes of aneurysm occlusion were evaluated by the modified Raymond–Roy occlusion classification. We used the finite element method and computational fluid dynamics to investigate the hemodynamics after shortened low-profile visible intraluminal support stent deployment. Results Immediately after treatment, the modified Raymond-Roy occlusion classification was significantly better in the shortening group than in the non-shortening group ( p<0.05). The latest angiographic outcomes showed the same tendency. Hemodynamic analysis by computational fluid dynamics suggested an adequate flow diversion effect with the use of our intentional shortening method. Conclusions Stent-assisted coil embolization using this technique showed good results of a high complete occlusion rate and low complication rate. These findings suggest that shortened low-profile visible intraluminal support stent deployment yields a flow diversion effect and may lead to early intra-aneurysmal thrombus formation.

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Delayed Bleeding of Unruptured Intracranial Aneurysms After Coil Embolization: A Retrospective Case Series

World Neurosurgery ◽

10.1016/j.wneu.2021.02.061 ◽

2021 ◽

Vol 149 ◽

pp. e135-e145

Author(s):

Kazuhiro Ando ◽

Hitoshi Hasegawa ◽

Tomoaki Suzuki ◽

Shoji Saito ◽

Kohei Shibuya ◽

...

Keyword(s):

Coil Embolization ◽

Intracranial Aneurysms ◽

Case Series ◽

Retrospective Case ◽

Delayed Bleeding ◽

Retrospective Case Series ◽

Unruptured Intracranial Aneurysms

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Long-term outcomes of coil embolization of unruptured intracranial aneurysms

Journal of Neurosurgery ◽

10.3171/2017.6.jns17174 ◽

2018 ◽

Vol 129 (6) ◽

pp. 1492-1498 ◽

Cited By ~ 6

Author(s):

Masaomi Koyanagi ◽

Akira Ishii ◽

Hirotoshi Imamura ◽

Tetsu Satow ◽

Kazumichi Yoshida ◽

...

Keyword(s):

Coil Embolization ◽

Intracranial Aneurysms ◽

Additional Treatment ◽

Long Term Outcomes ◽

Unruptured Intracranial Aneurysms ◽

Risk Of Rupture ◽

Long Term Follow Up ◽

Multiple Stroke

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.

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Commentary: Delayed Intracranial Parenchymal Changes After Aneurysmal Coil Embolization Procedures for Unruptured Intracranial Aneurysms

Operative Neurosurgery ◽

10.1093/ons/opz357 ◽

2019 ◽

Vol 19 (1) ◽

pp. E39-E40 ◽

Cited By ~ 1

Author(s):

Denise Brunozzi ◽

Ali Alaraj

Keyword(s):

Coil Embolization ◽

Intracranial Aneurysms ◽

Unruptured Intracranial Aneurysms

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Delayed Intracranial Parenchymal Changes After Aneurysmal Coil Embolization Procedures for Unruptured Intracranial Aneurysms

Operative Neurosurgery ◽

10.1093/ons/opz299 ◽

2019 ◽

Vol 19 (1) ◽

pp. 76-83 ◽

Cited By ~ 3

Author(s):

Ichiro Nakagawa ◽

Hun Soo Park ◽

Masashi Kotsugi ◽

Yudai Morisaki ◽

Takeshi Wada ◽

...

Keyword(s):

Coil Embolization ◽

Intracranial Aneurysms ◽

Perioperative Complications ◽

White Matter Lesions ◽

Steroid Treatment ◽

Cerebral White Matter ◽

Nickel Allergy ◽

Skin Patch ◽

Unruptured Intracranial Aneurysms ◽

Inflammatory Changes

Abstract BACKGROUND With the recent advances in endovascular treatment devices, it has become standard in wide-neck or large intracranial aneurysms to perform coil embolization with adjunctive techniques. However, device-related perioperative complications have been reported because of the use of more complex systems. OBJECTIVE To investigate patients who developed multiple parenchymal lesions after undergoing coil embolization for treating an unruptured intracranial aneurysm. METHODS This study investigated 305 consecutive patients who underwent coil embolization of unruptured intracranial aneurysms between 2015 and 2017. Delayed inflammatory changes referred to the delayed observation of multiple cerebral white matter lesions on follow-up magnetic resonance imaging at an area corresponding to the perfused area of the treatment target vessel. The timing and pattern of onset, device used, the combined use of adjunctive techniques, and the clinical course after steroid treatment were retrospectively investigated. RESULTS The 7 patients (2.3%) who showed delayed inflammatory changes were all women with a mean age of 59 yr. A mean duration from treatment to onset was 28 d. Symptoms were convulsions in 3 patients, hemiplegia in 2 patients, and homonymous hemianopia in 1 patient. All 7 patients were treated with adjunctive technique including stents, double catheter method, and balloon assist. Response to steroid treatment was satisfactory both clinically and on imaging in all 7 patients. Skin patch test was positive for nickel allergy in 2 patients. CONCLUSION Clinicians must be fully aware of symptomatic delayed inflammatory changes may occur after endovascular aneurysmal treatment with the use of various devices.

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