a flexible tubular body extending along a longitudinal axis between a proximal end and a distal end and having a proximal part, which includes the proximal end, and a distal part, which includes the distal end, the tubular body comprising:

a multipurpose conduit extending parallel to the longitudinal axis and opening out at the proximal end, at the distal end and into one or more injection orifices situated in the distal part such that a guide wire having a predetermined external diameter can be inserted into the multipurpose conduit, through both the distal end of the multipurpose conduit and the proximal end of the multipurpose conduit, and the tubular body can slide along the guide wire, wherein the multipurpose conduit has a diameter greater than the external diameter of the guide wire along an entire length of the tubular body, except for an end part of the distal part, where the multipurpose conduit has a diameter substantially equal to the external diameter of the guide wire, wherein the multipurpose conduit is configured for injection of a contrast agent of a viscosity in a patient through the proximal end of the multipurpose conduit, and through the one or more injection orifices, when the guide wire is in an inserted configuration in the multipurpose conduit;

an inflatable angioplasty balloon positioned around the tubular body in the distal part; and

an inflation conduit extending parallel to the longitudinal axis and opening out at the proximal end and into the angioplasty balloon, such that injection of a fluid into the angioplasty balloon will inflate the angioplasty balloon, the inflation conduit being leaktight with respect to the multipurpose conduit.