According to the invention, a fluid exchange catheter is provided, which catheter has a proximal end and a distal end, and comprises an obligatory lumen having a proximal end and a distal end, the distal end of the obligatory lumen having a closed shape, wherein a lumen wall of the obligatory lumen forms a distal wall portion at the distal end of the obligatory lumen, the distal wall portion comprising at least one lumen opening in the lumen wall. Furthermore, the catheter comprises at least one additional lumen having a proximal end and a distal end, the distal end being arranged inside the obligatory lumen remote from the distal end of the obligatory lumen such that fluid exiting the at least one additional lumen flows inside the distal end of the obligatory lumen. Here, the distal wall portion exhibits expansibility in at least an area surrounding the at least one lumen opening in order to provide an unblocking function for removing blockage of the catheter, any lumen can be adapted for fluid infusion and/or fluid aspiration, and an unblocking of the catheter is effected by altering the width of the at least one lumen opening by changing the infusion and/or aspiration fluid pressure of the catheter, the infusion and/or aspiration fluid pressure being different from an outer pressure acting on the outside of the distal wall portion of the obligatory lumen.Linvention concerne un cathéter déchange de fluide, lequel cathéter a une extrémité proximale et une extrémité distale et comprend une lumière obligatoire ayant une extrémité proximale et une extrémité distale, lextrémité distale de la lumière obligatoire ayant une forme fermée, une paroi de lumière de la lumière obligatoire formant une partie de paroi distale à lextrémité distale de la lumière obligatoire, la partie de paroi distale comprenant au moins une ouverture de lumière dans la paroi de lumière. En outre, le cathéter comprend au moins une lumière supplémentaire ayant une extrémité proximale et une extrémi
