CLOSED EXCHANGE SYSTEM

The invention provides a means of closed exchange of implanted medical device components. An exchanger is brought into contact with the implanted medical device in situ. The component is withdrawn from the implanted device and brought into a closed chamber of the exchanger. Without breaking the contact between implanted device and exchanger, the replacement component is then moved from its position in the exchanger, and inserted into the correct position in the implanted device. The surfaces of the implanted device are not brought into contact with the outside environment, thereby minimizing the possibility of introducing contaminants into the body during the exchange process. The invention is particularly useful for devices that are difficult to position and re-position, thus making it advantageous to exchange only an expended component, rather than the entire device.