Various systems and methods are provided for reducing pressure at an outflow of a duct such as the thoracic duct or the lymphatic duct. In one embodiment, an indwelling catheter 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 can include first and second restrictors each configured to at least partially occlude the vein within which the catheter is implanted and thus to restrict fluid flow within the vein when the restrictors are activated. The restrictors can each be configured to move between an activated configuration, in which the restrictor occludes the vein, and a relaxed configuration, in which the restrictor does not occlude the vein. The catheter can include a pump, such as an axial motor pump, configured to pump fluid through the catheter.