Methods are provided for partial aortic occlusion for cerebral perfusion augmentation in patients suffering from global or focal cerebral ischemia. Alternatively, the methods can be used to partially occlude aortic blood flow to condition the spinal cord to secrete neuroprotective agents prior to abdominal aortic aneurysm repair. The methods can also be used to partially occlude the renal arteries to reduce renin secretion in hypertensive patients. Partial occlusion of a vessel can be accomplished by a device comprising an elongate catheter, a distally mounted expandable occluder, a variable flow mechanism, and a manometer. The occluder may comprise two conical shells or an inflatable ring-shaped balloon disposed about a cylindrical sleeve. Other medical devices, such as an atherectomy catheter, can be inserted distal the occluder to provide therapeutic intervention.