A method for improving a flow condition through a catheter includes coupling a distal end of a first conduit of a tubing set to an aspiration lumen of an aspiration catheter, coupling a proximal end of the first conduit to a vacuum source, coupling a distal end of a second conduit of the tubing set to a supply lumen of the aspiration catheter, coupling a proximal end of the second conduit to a first fluid source, inserting a distal end of a sheath within the vasculature of a subject, placing the aspiration catheter through the sheath and advancing the aspiration catheter such that an open distal end of the aspiration lumen of the aspiration catheter is distal to a distal end of the sheath and is in proximity to a thrombus within a blood vessel of a subject, coupling an extension conduit in fluid communication with a lumen of the sheath to a second fluid source, and activating a pump such that pressurized fluid from the first fluid source is applied to the supply lumen of the aspiration catheter, wherein when insufficient flowable material is present adjacent the open distal end of the aspiration lumen, fluid from the second fluid source is caused to flow through the lumen of the sheath.
