Abstract: The present invention provides a drainage catheter for the therapeutic or diagnostic aspiration of fluid or air from the thoracic or abdominal cavities. The present invention provides a catheter needle, a catheter, a needle hub, a stop cock, and a self-sealing valve. The stop cock is removably secured to the catheter by use of a Luer connection. The stop cock is additionally removably secured to the self-sealing valve, again by use of a Luer connection. Use of the Luer connection allows the catheter to be disassembled from the stop cock as well as allows the stop cock to be disassembled from the self-sealing valve. This invention allows the additional medical procedures while the catheter still remains in the patient.