A catheter assembly comprising: a control handle; a medical device; an inner member having a distal portion for mounting the medical device and a proximal portion having a proximal end attached to the control handle, the inner member also including a guide wire receiving member defining a lumen for receiving a guide wire and being attached to the proximal portion, the guide wire receiving member being configured to extend from a proximal end to a distal end; and an outer member having a proximal end and a distal end, the proximal end being connected to the control handle, a restraining sheath portion forming part of the outer member and being adapted to at least partially cover the medical device and be retractable by actuation of the control handle to uncover the medical device, the outer member further including an intermediate portion which extends from a proximal end and is attached to the distal restraining sheath portion,and a proximal outer member having a distal end bonded to the proximal end of the intermediate portion, the distal end of the proximal outer member extending into the proximal end of the intermediate portion and the intermediate portion having a larger diameter than the distal end of the proximal outer member thereby forming a space between the proximal outer member and the intermediate portion, said space defining a distal opening in the outer member in communication with the guide wire receiving member, the inner member and the outer member being dimensioned for relative axial movement along a longitudinal axis such that when the outer member is retracted proximally via the control handle the guide wire receiving member remains unattached to the intermediate portion which moves back proximally, characterised in that the proximal portion of the inner member is made from a tubular member and defines a passage for the introduction of a flushing fluid into the catheter assembly. a control handle; a medical device; an inner member having a distal portion for mounting the medical device and a proximal portion having a proximal end attached to the control handle, the inner member also including a guide wire receiving member defining a lumen for receiving a guide wire and being attached to the proximal portion, the guide wire receiving member being configured to extend from a proximal end to a distal end; and an outer member having a proximal end and a distal end, the proximal end being connected to the control handle, a restraining sheath portion forming part of the outer member and being adapted to at least partially cover the medical device and be retractable by actuation of the control handle to uncover the medical device, the outer member further including an intermediate portion which extends from a proximal end and is attached to the distal restraining sheath portion,and a proximal outer member having a distal end bonded to the proximal end of the intermediate portion, the distal end of the proximal outer member extending into the proximal end of the intermediate portion and the intermediate portion having a larger diameter than the distal end of the proximal outer member thereby forming a space between the proximal outer member and the intermediate portion, said space defining a distal opening in the outer member in communication with the guide wire receiving member, the inner member and the outer member being dimensioned for relative axial movement along a longitudinal axis such that when the outer member is retracted proximally via the control handle the guide wire receiving member remains unattached to the intermediate portion which moves back proximally, characterised in that the proximal portion of the inner member is made from a tubular member and defines a passage for the introduction of a flushing fluid into the catheter assembly.