A catheter comprising: a tube having at least one lumen (404,406), with a distal end of the tube terminating at a cap; at least one elongate element, at least part of which extends forwardly of the distal end of said tube to a fixed orientation at which a distal end of said at least one elongate element extends beyond said distal end of said tube by a fixed amount, with a distal end of the at least one elongate element being fixed to a tip element; and at least one selectably inflatable balloon communicating with at least one of said at least one lumen, said at least one selectably inflatable balloon having a forward end and a rearward end, said rearward end of said balloon being located adjacent said distal end of said tube at a rearward balloon end mounting location and said forward end of said balloon being located adjacent a distal end of said at least one elongate element at a forward balloon end mounting location, wherein said balloon is configured such that when said at least one elongate element is in said fixed orientation and said balloon is in a deflated operative orientation, the distance between said rearward balloon end mounting location and said forward balloon end mounting location is greater than the distance between said rearward balloon end mounting location and said forward balloon end mounting location when said balloon is an inflated operative orientation, characterised in that, when the balloon is in the deflated operative orientation, the at least one elongate element extends along an axis generally parallel to and spaced from a longitudinal axis of the tube, the cap and the tip, with inflation of the balloon producing bowing of said at least one elongate element in a direction which is determined at least partially by the spatial relationship between axes and to an extent which is a predetermined function of the amount of inflation, with said bowing of said elongate element producing an asymmetric, inflated balloon configuration. a tube having at least one lumen (404,406), with a distal end of the tube terminating at a cap; at least one elongate element, at least part of which extends forwardly of the distal end of said tube to a fixed orientation at which a distal end of said at least one elongate element extends beyond said distal end of said tube by a fixed amount, with a distal end of the at least one elongate element being fixed to a tip element; and at least one selectably inflatable balloon communicating with at least one of said at least one lumen, said at least one selectably inflatable balloon having a forward end and a rearward end, said rearward end of said balloon being located adjacent said distal end of said tube at a rearward balloon end mounting location and said forward end of said balloon being located adjacent a distal end of said at least one elongate element at a forward balloon end mounting location, wherein said balloon is configured such that when said at least one elongate element is in said fixed orientation and said balloon is in a deflated operative orientation, the distance between said rearward balloon end mounting location and said forward balloon end mounting location is greater than the distance between said rearward balloon end mounting location and said forward balloon end mounting location when said balloon is an inflated operative orientation, characterised in that, when the balloon is in the deflated operative orientation, the at least one elongate element extends along an axis generally parallel to and spaced from a longitudinal axis of the tube, the cap and the tip, with inflation of the balloon producing bowing of said at least one elongate element in a direction which is determined at least partially by the spatial relationship between axes and to an extent which is a predetermined function of the amount of inflation, with said bowing of said elongate element producing an asymmetric, inflated balloon configuration.