Patent ID: 7314588

Claim:
A method of making a balloon catheter having a balloon with a proximal and distal skirt section sealingly secured to an elongated catheter shaft, a working length section, a proximal tapered section having a proximal end at a distal end of the proximal skirt section and a distal end at a proximal end of the working length section, and a distal tapered section having a proximal end at a distal end of the working length section and a distal end at a proximal end of the distal skirt section, such that the junction between the working length and each tapered section forms an internal shoulder, comprising: a) securing a balloon first layer formed of a first polymeric material to a balloon second layer formed of a second polymeric material, the second layer comprising a first sublayer formed of the second polymeric material and a second sublayer formed of the second polymeric material fused to a central section of the first sublayer so that a wall thickness of the second layer along the central working length section of the balloon from the proximal to the distal end of the working length section is greater than the wall thickness of the second layer along at least one of the proximal tapered section and the distal tapered section of the balloon from the proximal to the distal end of the tapered section in a noninflated configuration of the balloon, with the second layer in the noninflated configuration having a substantially uniform wall thickness along the proximal tapered section and a substantially uniform wall thickness along the distal tapered section of the balloon, so that the central working length section of the balloon defines a thickened wall portion of the balloon; and b) securing the proximal skirt section and the distal skirt section of the balloon to an elongated catheter shaft so that an interior of the balloon is in fluid communication with a lumen of the shaft.