
Quantitative effects of coil packing density on cerebral aneurysm fluid dynamics: an in vitro steady flow study.
Babiker M Haithem,Gonzalez L Fernando,Albuquerque Felipe,Collins Daniel,Elvikis Arius,Frakes David H
Annals of biomedical engineering
Over the past 15 years, coil embolization has emerged as an effective treatment option for cerebral aneurysms that is far less invasive than the long-standing convention of surgical clipping. However, aneurysm recurrence after coil embolization is not uncommon: recurrence rates as high as 50% have been reported in the literature. One factor that may contribute to recurrence after coiling is residual flow into the aneurysmal sac. At present, there is limited quantitative knowledge of the relationship between coil packing density and aneurysmal inflow. We present an in vitro fluid dynamic study of basilar tip aneurysm models that elucidates this relationship. At physiologically normal flow rates, we found that a packing density of 28.4% decreased aneurysmal inflow by 31.6% in a wide-neck model, and that a packing density of 36.5% decreased aneurysmal inflow by 49.6% in a narrow-neck model. Results also indicated that coiling reduced aneurysmal inflow more significantly at lower parent vessel flow rates, and that coiling reduced neck-plane velocity magnitudes more significantly for narrow-neck aneurysms. Our study provides novel quantitative information that could ultimately contribute to improved outcomes for patients with cerebral aneurysms by enabling more effective coil embolization.
10.1007/s10439-010-9995-4
Injectable hydrogels for vascular embolization and cell delivery: The potential for advances in cerebral aneurysm treatment.
Kim Seungil,Nowicki Kamil W,Gross Bradley A,Wagner William R
Biomaterials
Cerebral aneurysms are vascular lesions caused by the biomechanical failure of the vessel wall due to hemodynamic stress and inflammation. Aneurysmal rupture results in subarachnoid hemorrhage often leading to death or disability. Current treatment options include open surgery and minimally invasive endovascular options aimed at secluding the aneurysm from the circulation. Cerebral aneurysm embolization with appropriate materials is a therapeutic approach to prevent rupture and the resultant clinical sequelae. Metallic platinum coils are a typical, practical option to embolize cerebral aneurysms. However, the development of an alternative treatment modality is of interest because of poor occlusion permanence, coil migration, and coil compaction. Moreover, minimizing the implanted foreign materials during therapy is of importance not just to patients, but also to clinicians in the event an open surgical approach has to be pursued in the future. Polymeric injectable hydrogels have been investigated for transcatheter embolization and cell therapy with the potential for permanent aneurysm repair. This review focuses on how the combination of injectable embolic biomaterials and cell therapy may achieve minimally invasive remodeling of a degenerated cerebral artery with promise for superior outcomes in treatment of this devastating disease.
10.1016/j.biomaterials.2021.121109
How to perform intra-aneurysmal coil embolization after Pipeline deployment: a study from a hemodynamic viewpoint.
Journal of neurointerventional surgery
BACKGROUND:Pipeline embolization device (PED) deployment combined with coil therapy for large complex intracranial aneurysms is effective and considered superior to PED deployment alone. However, the optimal strategy for use of coils remains unclear. We used patient-specific aneurysm models and finite element analysis to determine the ideal packing density of coils after PED placement. METHODS:Finite element analysis was used to provide a higher-fidelity model for accurate post-treatment computational fluid dynamics analysis to simulate the real therapeutic process of PED and all coils. We then calculated and analyzed the reduction ratio of velocity to identify the hemodynamic change during PED deployment and each coil embolization. RESULTS:Sixteen consecutive patients underwent PED plus coil procedures to treat internal carotid artery intracranial aneurysms. After PED deployment, the intra-aneurysmal flow velocity significantly decreased (15.3 vs 10.0 cm/s; p<0.001). When the first coil was inserted, the flow velocity in the aneurysm further decreased and the reduction was significant (10.0 vs 5.3 cm/s; p<0.001). Analysis of covariance showed that the effect of the reduction ratio of velocity of the second coil was significantly lower than that of the first coil (p<0.001)-that is, when the packing density increased to 7.06%, the addition of coils produced no further hemodynamic effect. CONCLUSION:Adjunct coiling could improve the post-PED hemodynamic environment in treated intracranial aneurysms. However, dense packing is not necessary because the intra-aneurysmal hemodynamics tend to stabilize as the packing density reaches an average of 7.06% or after insertion of the second coil.
10.1136/neurintsurg-2021-018361
Successful Coil Embolization of an Aneurysm in the Arc of Bühler.
Sugihara Fumie,Murata Satoru,Uchiyama Fumio,Watari Jun,Tajima Hiroto,Kumita Shin-Ichiro
Journal of Nippon Medical School = Nippon Ika Daigaku zasshi
In the present report, we describe a case of a patient with an asymptomatic aneurysm in the arc of Bühler (AOB), which was successfully treated by transcatheter arterial embolization. The patient presented with severe stenosis of the celiac trunk, which was suspected to be due to median arcuate ligament syndrome. Arteriography of the superior mesenteric artery indicated a rapid stream in an aneurysm in the AOB. Hence, embolization was carefully performed using detachable coils and microcoils. An arteriography performed after embolization did not show any aneurysm, and the hepatic artery and splenic artery could be detected via the pancreatic arcade, originating from the superior mesenteric artery. The AOB is a persistent embryonic ventral anastomosis present between the superior mesenteric artery and the celiac artery. This anastomotic artery is independent of the gastroduodenal artery and the dorsal pancreatic artery, and is extremely rare, with an incidence of <4%. Aneurysms of the AOB are even more uncommon, and such cases have been reported in association with stenosis or occlusion of the celiac trunk. Open surgical aneurysmectomy, with or without reconstruction, is the conventional treatment for such aneurysms. However, rapid advances in interventional radiology have enabled the safe and effective treatment of visceral aneurysms via transcatheter arterial embolization. Based on the current findings, we believe that transcatheter arterial embolization is a minimally invasive and valuable method that may serve as an initial treatment option for aneurysms of the AOB.
10.1272/jnms.83.196
Endothelial cell proliferation in swine experimental aneurysm after coil embolization.
Mitome-Mishima Yumiko,Yamamoto Munetaka,Yatomi Kenji,Nonaka Senshu,Miyamoto Nobukazu,Urabe Takao,Arai Hajime,Oishi Hidenori
PloS one
After coil embolization, recanalization in cerebral aneurysms adversely influences long-term prognosis. Proliferation of endothelial cells on the coil surface may reduce the incidence of recanalization and further improve outcomes after coil embolization. We aimed to map the expression of proliferating tissue over the aneurysmal orifice and define the temporal profile of tissue growth in a swine experimental aneurysm model. We compared the outcomes after spontaneous thrombosis with those of coil embolization using histological and morphological techniques. In aneurysms that we not coiled, spontaneous thrombosis was observed, and weak, easily detachable proliferating tissue was evident in the aneurysmal neck. In contrast, in the coil embolization group, histological analysis showed endothelial-like cells lining the aneurysmal opening. Moreover, immunohistochemical and morphological analysis suggested that these cells were immature endothelial cells. Our results indicated the existence of endothelial cell proliferation 1 week after coil embolization and showed immature endothelial cells in septal tissue between the systemic circulation and the aneurysm. These findings suggest that endothelial cells are lead to and proliferate in the former aneurysmal orifice. This is the first examination to evaluate the temporal change of proliferating tissue in a swine experimental aneurysm model.
10.1371/journal.pone.0089047
Periprocedural safety of aneurysm embolization with the Medina Coil System: the early human experience.
Turk Aquilla S,Maia Orlando,Ferreira Christian Candido,Freitas Diogo,Mocco J,Hanel Ricardo
Journal of neurointerventional surgery
INTRODUCTION:Intracranial saccular aneurysms, if untreated, carry a high risk of morbidity and mortality from intracranial bleeding. Embolization coils are the most common treatment. We describe the periprocedural safety and performance of the initial human experience with the next generation Medina Coil System. METHODS:The Medina Coil System is a layered three-dimensional coil made from a radiopaque, shape set core wire, and shape memory alloy outer coil filaments. Nine aneurysms in five patients were selected for treatment with the Medina Coil System. RESULTS:Nine aneurysms in five patients, ranging from 5 to 17 mm in size in various locations, were treated with the Medina Coil System. No procedural or periprocedural complications were encountered. Procedure times, number of coils used to treat the aneurysm, and use of adjunctive devices were much less than anticipated if conventional coil technology had been used. CONCLUSIONS:The Medina Coil System is a next generation coil that combines all of the familiar and expected procedural safety and technique concepts associated with conventional coils. We found improved circumferential aneurysm filling, which may lead to improved long term outcomes, with fewer devices and faster operating times.
10.1136/neurintsurg-2014-011585