The zones are perpendicular/oblique to the stent (1). The stent is formed by circular portions (5) with openwork structure and connected by omega shaped ruptible bridges. The openings (11) are constituted by an inflatable balloon attached between the circular portions and inflated to carry out a rupture of the bridges, which has a thinned zone. The portion is formed by a zigzag wire connected by the bridges. The balloon has a truncated form and/or annular cross section and is formed by small balloons.
