A catheter (4) comprising a catheter body (8) which extends from a proximal end (12) to a distal end (16) in a longitudinal direction (X X) wherein the catheter body (8) comprises a core (24) embedded inside a flexible outer covering layer (28) and being a hollow tubular body which defines at least one lumen (20) wherein the core (24) comprises a plurality of pairs of ribs (40) which extend inside said outer covering layer (28) wherein said ribs (40) extend from an attachment end (44) at which they connect to each other to a free end (48) opposite the attachment end (44) wherein the line joining the attachment ends (44) of the pairs of ribs (40) defines a dorsal side (36) of the catheter body (8). The free ends (48) of the ribs (40) coupled in the same pairs are separate from each other identifying at least one discontinuity (52) of said ribs (40) said discontinuity (52) being positioned on a ventral side (56) opposite said dorsal side (36) wherein a first plane (P) being defined perpendicular to the longitudinal element (32) and passing through the attachment end (44) of a rib (40) and a second plane (Q) being defined passing through the free end (48) and through the attachment end (44) of the same rib (40) said planes (P Q) are inclined to each other so as to form an acute angle (A) on the side of the proximal end (12) or of the distal end (16).
