A flexible, hermetically sealed enclosure device allows for the controlled insertion of an implantable device into the body of a patient. A series of bellows can be used to interconnect a number of rigid containers, each containing electronic or other components necessary for the implantable device. The bellows provide flexibility, columnar strength, and torqueability (for steering), while protecting the internal components. The bellows also can be welded to the containers to form a hermetic seal that can be electrically continous, whereby standard wiring and components can be used without fear of corrosion or contamination. Such an enclosure can be used with systems such as an intravascular implantable pacing, drug delivery, or defibrillation system.