Stability of coil emboli: an in vitro study.

Gianturco stainless steel coils were discharged into clear plastic tubes of varying sizes and subjected to pulsatile flow in order to study their behavior in a controlled, in vitro environment. When coils are too small for a given vessel, they tend to migrate distally or even proximally. Coils that are too large tend not to reform completely, limiting their cross-sectional area and potentially affecting their occlusive potential. Thus, each coil was tested in tubes of varying sizes and evaluated with regard to positional stability and extent of reformation.