A catheter assembly (10) comprises a first elongate tubular member (12) having a proximal end portion (14) defining a proximal end (15), a distal end portion (18) having an opening therein (20) and defining a distal end (22), and at least one lumen (24) defined between the proximal end (15) and the distal end (22). A second elongate tubular member (26) has a proximal end portion (28) defining a proximal end (30), a distal end portion (32) defining a distal end (34), and at least one lumen (36) defined between the proximal end (30) and the distal end (34). The second elongate tubular member (26) is received within the at least one lumen (24) of the first elongate tubular member (12), such that the distal end portion (32) of the second elongate tubular member (26) projects from the opening (20) in the distal end portion (18) of the first elongate tubular member (12). An elongate, shape- imparting element (38) is receivable in the at least one lumen (24, 36) of at least one of the first elongate tubular member (12) and the second elongate tubular member (26). The shape-imparting element (38) imparts a non-rectilinear shape to the distal end portion (18, 32) of at least one of the first elongate tubular member (12) and the second elongate tubular member (26).Linvention porte sur un ensemble cathéter (10) qui comprend un premier élément tubulaire allongé (12) ayant une partie dextrémité proximale (14) définissant une extrémité proximale (15), une partie dextrémité distale (18) comportant une ouverture dans celle-ci (20) et définissant une extrémité distale (22), et au moins une lumière (24) définie entre lextrémité proximale (15) et lextrémité distale (22). Un second élément tubulaire allongé (26) a une partie dextrémité proximale (28) définissant une extrémité proximale (30), une partie dextrémité distale (32) définissant une extrémité distale (34) et au moins une lumière (36) définie entre lextrémité proximale (30) et lextrémité distale (34). Le second élément tubulair
