US Patent 7537580 Intravascular dilatation infusion catheter

A medical device comprises a catheter having at least one catheter shaft, which defines an inflation lumen for transport of an inflation fluid therethrough. The inflation fluid comprises a coolant. An expandable balloon, which has a proximal cone, distal cone, and a body region therebetween, is engaged to a distal region of the at least one catheter shaft. The balloon interior is in fluid communication with the inflation lumen. A portion of the catheter distal of the balloon body defines at least one port that is in fluid communication with the inflation lumen and the balloon interior.