Abstract: A pressure sensitive valve comprising: (a) an outer balloon adapted for intravascular insertion comprising at least one hole adapted for ejection of a fluid; (b) an inner structure adapted to substantially fill the outer balloon; (c) at least one selectively blockable flow path between the outer balloon and the inner structure, at least some of the at least one flow path in fluid communication with at least one of the at least one hole; (d) an inlet port to the at least one flow path; and (e) a pressure source operable to provide a fluid at least at a selected injection pressure to the inlet port. A flow of the fluid along the at least one selectively blockable flow path to the at least one hole is prevented when the pressure source provides any pressure below the selected injection pressure and a flow of the fluid along the at least one selectively blockable low path to the at least one hole occurs when the pressure source provides pressure at or above the selected injection pressure.