Animal experiment and clinical application of self-made mechanically detachable coils

OBJECTIVE: To evaluate the practical and thrombogenetic characteristics of self-made mechanically detachable coils by the animal experiment and primary clinical application. METHOD: The bifurcation type of aneurysm model was established on rabbit and embolized with self-made mechanically detachable coils 2 weeks after surgery. 24 coils were used in 5 experimental aneurysms. Control angiography was performed and the rabbits were sacrificed 2 - 3 weeks after the embolization. The embolized aneurysm samples were examined by pathologist. Ten patients were treated with self-made mechanically detachable coils in primary clinical application. They were divided into aneurysms (7 patients), traumatic carotid-carvenous fistulas (2), dural arterio-venous fistula in carvenous sinus region (1). 146 coils were used totally and all were delivered with mechanical detachable system (MDS Balt co. France). RESULT: Pathologically, the cavities of rabbit aneurysm models were occluded by tungsten coils (2 complete, 3 almost complete). The coils were trapped in granulation tissue which was covered by a thin layer of endothelium on the surface facing the blood flow. In the coils dense packing ones, the aneurysms were completely excluded from the parent circulation by neointimal layers. In the practice procedures, the coils fit MDS (Balt co. France) very well and can be delivered, withdrew and detached smoothly. CONCLUSION: The self-made mechanically detachable coils have practical reliability and evident thrombogenetic effects.