of the catheter 100 may then be about 7 french or less or about 65 to 91 mils in a second embodiment described below a catheter for use in the coronary arteries is described of course which catheter is used in which artery is a matter to be determined by the physician taking into account such factors as the size of the individual patient 39 s affected arteries etc the outer tube 103 houses the catheter 100 while the latter traverses the length of the guide catheter 102 the outer tube 103 may have a diameter of about 4 french to 7 french and the same may be made of polyether blockamide poly butylene terephtalate polyurethane polyamide polyacetal polysulfone polyethylene ethylene tetrafluoroethylene and other similar materials the distal end of the outer tube 103 adjoins the proximal end of the dual balloon 134 the outer tube 103 provides a convenient location for mounting a proximal end of an outer balloon 104 within the dual balloon 134 and further may provide an inlet 128 for providing a fluid such as a liquid to a first interior volume 106 between the dual balloons in some cases an inlet 128 per se may not be necessary the fluid which may also be a sub atmospheric level of gas or air may be provided during manufacture in the first interior volume 106 in this case the proximal and distal ends of the first interior volume may be sealed during manufacture the inlet.