A device for introducing an implantable appliance into a catheter including an attachment connected to said open end of catheter, the attachment being closed at its open end by a flexible check valve. A cartridge is removably attachable to the catheter attachment with the cartridge when attached having a front end portion communicating with the catheter and its other end closed by a second flexible check valve. This second check valve is open when the appliance to be implanted is introduced into the cartridge but thereafter is kept closed and the front end portion of the cartridge with the appliance now inside is inserted into to the first check valve of the attachment.