• Journal of Biomedical Engineering Research
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• v.23 no.5
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• pp.375-383
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• 2002

Aneurysm embolisation method using coils have been widely used. Micro coils are introduced via a small catheter, and are packed inside of aneurysm sac, which induces intraaneurysmal flow stagnation and thrombus formation. When partial blocking of an aneurysm is inevitable, the location of coils is important since it changes the flow patterns inside the aneurysm, which affect the embolisation process. We measured the flow field inside the partially blocked lateral aneurysm models in vitro, and tried to suggest the effective locations of coils for aneurysm embolisation. Velocity fields are measured using a particle image velocitimeter for different coil locations- proximal neck, distal neck, proximal dome and distal dome. Flow into the aneurysm sac was significantly reduced in the distally blocked models, and coils at distal neck blocked inflow more effectively comparing to those at distal dome. This study suggests that distal neck should be the most effective location for aneurysm embolisation.

• Journal of Biomedical Engineering Research
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• v.25 no.4
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• pp.295-300
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• 2004

Coil embolization technique has been used recently to treat cerebral aneurysms. When a giant or a multilobular aneurysm are treated by roils, filling an aneurysm sac completely with coils is difficult and partial blocking of an aneurysm sac is inevitable. Blood flow characteristics, which nay affect the embolization process of an aneurysm sac, are changed by the locations of coils for the Partially blocked aneurysms. Blood flow fields are also influenced by the geometry of a parent vessel. In order to suggest the coil locations effective for aneurysm embolization, the blood flow fields of lateral aneurysm models were analyzed for the different coil locations and parent vessel geometries. Three dimensional pulsatile flow fields are analyzed by numerical methods considering non-Newtonian viscosity characteristics of blood. Flow rate into the aneurysm sac (inflow rate) and wall shear stress, which are suspected as flow dynamic factors influencing aneurysm embolization, are also calculated. Inflow rates were smaller and the low wall shear stress zones were larger in the neck blocked models compared to the dome blocked models. Smaller inflow and larger low wall shear stress zones in the distal neck blocked model imply that the distal neck should be the effective coil locations for aneurysm embolization.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.347-349
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• 1997

In this study, we designed a vascular occlusion device based on the principle that slowing blood flow would induce thrombosis. Tungsten, stainless steel and platinum were tested for finding a good embolic metallic coil. The primary coil and the second coil were done with heat treatment or different time. The pitch distance and the shape retention capability of second coil were characterized by SEM. To increase thrombogenicity, we tried to treat different proteins on steel coils: thrombin, gelatin and both gelatin and thrombin. To verify protein materials treated on coils, the surface of coil treated with different proteins were characterized using Laser Raman Spectrophotometer. After observation of embolic coils, the peptides bonds on theirs' surface were found. In order to compare the thrombogenicity of different embolic agents, we measured whole blood clotting time.

• Journal of Veterinary Clinics
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• v.30 no.2
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• pp.87-94
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• 2013

This retrospective study reviewed the clinical and diagnostic features, therapeutic outcome and compilations of interventional ductal occlusion in 37 dogs with patent ductus arteriosus (PDA). Malteses and female dogs were over-presented. Bounding pulse and left basal continuous murmur were most common findings in physical examination, while the differential cyanosis was rarely observed. Left ventricular (LV) enlargement patterns and sinus tachycardia were common in the ECG. Typical radiographic findings included LV elongation and triple bumps indicating left atrial (LA), aortic and pulmonary dilation. Echocardiographic features were typical shunt flow at the ductus arteriosus and marked LV dilation with mild to moderate mitral regurgitation (MR). The 32 of 37 dogs were interventionally treated with either thromboemolic coils (TCE) or Amplatz canine ductal occluder (ACDO). Transient hemoglobinuria caused by incomplete closure was occurred in 2 dogs treated with TCE, although the hemoglobinuria was disappeared within a week of intervention. The dislodgement of occlusion device was occurred in 2 dogs with TCE and 1 dog with ACDO. However there were no significant complications associated with this dislodgement, since those were dislodged at the lower pulmonary vasculature. We also found that no serious complications and no further medical intervention in 29 dogs having long-term follow-ups.