The invention relates to a balloon catheter, in particular for the widening of stents in fenestrations, being provided with a first inner balloon (4), a second outer balloon (5), with said second balloon (5) completely enclosing the first balloon (4), separate supply lines in the catheter (2) leading to the first (4) and second balloon (5), which allow the balloons (4, 5) to be pressurized independently of one another, a central lumen (3) for a guidewire, wherein in the expanded state, both balloons (4, 5) in the proximal region (P) have a diameter which is enlarged in relation to that of the distal region (D).
