Expandable contraceptive transcervical fallopian tube occlusion devices having mechanical fallopian tube attachment and delivery system

The invention provides intra-fallopian devices (10) to prevent conception. The device (10) is anchored within the fallopian tube by a lumen traversing region (24) of the resilient structure which has a helical outer surface, together with a portion of the resilient structure which is biased to form a bent secondary shape, the secondary shape having a larger cross section than the fallopian tube. The resilient structure is restrained in a straight configuration and transcervically inserted within the fallopian tube, where it is released. Optionally, permanent sterilization is effected by passing a current through the resilient structure to the tubal walls.