Methods and apparatuses for pumping blood within a blood vessel are described. The methods and apparatuses are can be used for renal decongestion by pumping blood through the kidney(s), thereby increasing a pressure gradient across the kidney(s). The apparatuses can include one or more inflatable elements that can be repeatedly inflated and deflated to cause a pumping action within the blood vessel. In some embodiments, the one or more inflatable elements are positioned within one or more stents.
