Endovascular treatment of cerebral aneurysms: An in vitro study with detachable platinum coils and tricellulose acetate polymer

OBJECTIVE. The purpose of our experimental study was to determine the effec tiveness of filling the cavity of in vitro aneurysms with detachable platin um coils and the combination of detachable platinum coils and liquid emboli c agent. MATERIALS AND METHODS. Silicone aneurysm models were connected to a circula tory system to simulate arterial flow. A microcatheter was used to introduc e detachable coils into the aneurysm cavities. First, platinum coils were i ntroduced until the point of minimal dense packing, indicated by aneurysmal circulatory exclusion. Packing was continued up to maximal dense packing, indicated by protrusion of the coil into the parent artery. Volumetric rati os (coil volume-aneurysm volume) were calculated for minimal and maximal de nse packing. Then, after purposeful undercoiling of aneurysm models, a micr opump system was used to fill the aneurysm by stepwise injection of tricell ulose acetate polymer through the coil mesh until angiographic aneurysm exc lusion was completed. The volumetric ratios of maximal packing with coils a nd tricellulose acetate polymer in relation to the aneurysm volume were cal culated. RESULTS. Maximal dense packing ratios with coils (mean, 32.5%; standard dev iation [SD], 3%) were slightly higher than those with the minimal dense pac king (mean, 28.2%; SD, 3%) but were always less than 37%. The ratios of pac king with the combined use of coils and tricellulose acetate polymer were g reater than 100% (mean, 124.4%; SD, 15%). CONCLUSION. Knowledge of the volumetric ratio of maximal dense packing was useful for effective filling with coils and tricellulose acetate polymer. T he combined use of coils and liquid polymer appeared more effective than th e use of coils alone for the complete occlusion of the aneurysm lumen.