Balloon catheter with a molded stepped balloon

1 - 10 . (canceled)

11 . An assembly comprising

a balloon catheter having a balloon mounted thereon near the distal end, and

a stent mounted over at least a portion of the balloon,

wherein the balloon comprises a structural layer formed of a polyurethane.

12 . An assembly as in claim 11 wherein the balloon has a molded configuration with a longitudinal axis, the balloon molded configuration, when viewed in longitudinal quarter section, comprises:

first and second waist segments spaced longitudinally apart from each other and defining a longitudinally intermediate region therebetween, each waist segment being bonded to the catheter,

first and second step segments within said intermediate region and spaced longitudinally apart from each other, each step segment being spaced radially from the longitudinal axis and from said waist segments, the second step segment being spaced radially from the longitudinal axis a greater distance than the first step segment,

a first diverging portion extending between the first waist segment and the first step segment,

a second diverging portion extending between the first step segment and the second step segment, and

a transition portion extending between the second step segment and the second waist segment.

13 . The assembly of claim 12 wherein the balloon is mounted on the catheter such that said second waist portion is located distally of the first waist portion.

14 . The assembly of claim 12 wherein the balloon is mounted on the catheter such that said second waist portion is located proximally of the first waist portion.

15 . An assembly comprising

a balloon catheter having an elongate tubular body, a distal end and a balloon mounted thereon near the distal end, and

a stent mounted over at least a portion of the balloon,

wherein the balloon is formed of material consisting essentially of a polyurethane.