A membrane-free perfusion catheter comprising an exchange surface havinga filament structure, a delivery unit for delivery of perfusion fluid to alumenof the filament structure in a manner to allow for an exchange of substancesbetween a medium surrounding the lumen and the perfusion fluid via thefilament structure, and a drain unit for draining the medium surrounding theexchange surface and/or for draining the perfusion fluid delivered to thelumen of the filament structure after the exchange of substances betweenthe medium surrounding the lumen and the perfusion fluid via the filamentstructure.
