The present invention relates to a device (1) having a tubular shape, comprising a body (2) and at least two extremities (3a, 3b), wherein at least one of these extremities (3a, 3b) has a V-shape (4) and comprises an opening (5) forming an ellipse (6), and wherein the angle α between i) the central and longitudinal axis (7) of the device (1) and ii) the tangential line (8) formed by said V-shape (4) is lower than 10°.