A method for deflating an expandable balloon of an irrigation catheter is disclosed where the expandable balloon is deflated if a pressure inside of the expandable balloon is greater than a threshold pressure.

Various systems and methods are provided for reducing pressure at an outflow of a duct, such as the thoracic duct or the lymphatic duct, for example, the right lymphatic duct. A catheter system can be configured to be at least partially implanted within a vein of a patient in the vicinity of an outflow port of a duct of the lymphatic system. The catheter system includes first and second selectively deployable restriction members each configured to be activated to at least partially occlude the vein within which the catheter is implanted and to thus restrict fluid within a portion of the vein. The catheter system includes an impeller configured to be driven by a motor to induce a low pressure zone between the restriction members by causing blood to be pumped through the catheter when the restriction members occlude the vein.