A renal flow system and method direct fluid into renal arteries from a location within the aorta. A renal flow assembly has a tapered tube that is adjustable between a radially collapsed condition for delivery to the location through a delivery sheath and a radially expanded condition that divides aortic flow into exterior and interior paths. The tube's wall is made from a sheet of flexible material, such as PTFE or ePTFE. Two, nickel-titanium rings radially support the tube's ends and are connected by a longitudinal spine support. A fluid delivery assembly injects drug to flow along the exterior flow path and the tubular wall directs the agent into the renal artery ostium. The tube's taper has localized shape for circumferential agent mixing to infuse both kidneys' renals. The flow assembly allows an interventional device, e.g. delivery catheter, to advance across the location while directing blood into the renals and perfusing downstream circulation. The renal flow assembly and distal device are used within a common guide sheath through a single puncture wound. Vasodilators, antioxidants, or diuretics are delivered to the kidneys to treat/prevent RCN, CHF, or ARF.