Devices and methods for blood flow regulation

A blood flow regulator for regulating a blood flow adjacent to an arteriovenous junction, the blood flow regulator comprising:

• a vascular fitment adapted for implantation at a vascular lumen, the vascular fitment comprising an adjustable flow restrictor adapted for influencing a blood flow rate through the vascular lumen and a protective frame enclosing the flow restrictor;
• and
• a flow controller adapted to communicate with the flow restrictor for controlling adjustment of the flow restrictor, wherein
• the flow restrictor is adjustable between at least a first state for permitting a first blood flow rate through the vascular lumen and a second state for permitting a second blood flow rate through the vascular lumen, the first and second blood flow rates differing from one another, and
• the protective frame comprises a plurality of pores formed therein, the plurality of pores comprising pores of varying sizes in which relatively larger pores are provided at a first end of the protective frame and relatively smaller pores are provided at a second end of the protective frame.