A catheter system with a proximal end and a distal end element at the proximal end to actuate a device at the distal end of the system, and an actuator element (32) that runs the length of the system, from the actuator element to the device and actuates the device by transmitting a physical force from the proximal end to the distal end and characterized by a pre-tensioner (40) near the distal end of the system, that can be set in a pre-tensioning disposition prior to actuation of the device, the pre-tensioner thereby reducing the magnitude of the physical force that must be transmitted from the proximal end when actuation of the device is required.