A drainage catheter system includes an elongate tube with proximal and distal ends and a filament extending the tube that is adjustable to create a closed loop at the distal end of the tube when the filament is retracted relative to the tube. The filament is coupled to the tube such that the filament and tube are prevented from being separated in the event that the tube and filament are cut at the proximal end at the conclusion of a drainage procedure. The filament can be attached to the tube near the distal end. The filament can be attached to the tube along its length. The catheter system can also include a retraction mechanism having a first fixed position and second fixed position, where the second fixed position retracts the filament proximally relative to the first fixed position by actuating a plunger.
