Abstract: Dilatation catheters for use in administering treatments to relieve stenotic regions within a body lumen are described. In one aspect of the invention, a two wire catheter system, of minimal diameter for treating distal arteries is disclosed. In addition, a number of various dilatation balloon configurations, for treating stenotic areas which are present in tortuous vessels, as well as hardened, or calcified stenotic portions are also described. Finally, a catheter system which provides a path for conducting blood past the stenosis and inflated dilatation balloon is discussed.