Drainage catheters for use in a variety of medical procedures are presented herein. The drainage catheter features an improved tension member locking mechanism. In use, once the drainage catheter is placed as desired, a second connector piece is rotated relative to a first connector piece to wind the tension member around a spooling region and pull the distal end of the catheter tube into a locked configuration. Once the tension member is tensioned, the first and second connector pieces are pulled into a locking engagement thereby securing the catheter tube in the locked configuration.