Abstract: A catheter includes: a tube having a distal end, a proximal end, and a tube body extending between the distal end and the proximal end, the tube having a tube wall and a first channel in the tube wall; a first elongated element located in the first channel of the tube, the first elongated element slidably moveable in the first channel relative to the tube wall; and a suction port configured to apply suction in the first channel; wherein a first part of the tube wall is configured to deform to apply a first force against the first elongated element in response to the suction in the first channel.