Patent ID: 6890318

Claim:
A balloon catheter, comprising: a) an elongated shaft having an inflation lumen, a guidewire lumen, a proximal shaft section which defines a proximal portion of the inflation lumen and which comprises a tubular member having a proximal end and a distal end, and a distal shaft section which defines a distal portion of the inflation lumen in fluid communication with the proximal portion of the inflation lumen, the distal shaft section comprising i) a first distal outer tubular member having a proximal end secured to the distal end of the proximal shaft section tubular member; ii) a second distal outer tubular member having a proximal end secured to a distal end of the first distal outer tubular member; and iii) an inner tubular member disposed within the first and second distal outer tubular members and defining a guidewire lumen, the guidewire lumen having a guidewire proximal port formed by a side opening extending through a sidewall of the outer tubular member with a section of the inner tubular member in the side opening and fused to the sidewall of the outer tubular member, and the second distal outer tubular member having an inner surface which extends around a circumference of the second distal outer tubular member and which is spaced apart from the outer surface of the inner tubular member so that the inflation lumen in the second distal outer tubular member has an annular shape around the outer surface of the inner tubular member, and a portion of the first distal outer tubular member being fused to an outer surface of the inner tubular member, the portion extending from the proximal end of the inner tubular member to a location proximal to the second distal outer tubular member; and b) an inflatable balloon on the distal shaft section having a proximal end secured to the distal end of the second distal outer tubular member, a distal end secured to the inner tubular member, and an interior in fluid communication with the inflation lumen.