A cannula for an implantable pump comprises an elongate body having a channel therethrough and narrowing at a distal end thereof. A filter is integral with the body at a proximal end thereof. The filter (i) has a cross- section larger than a flow cross-section of the channel and (ii) defines openings that each have a height no greater than 2 µm. Means are provided for connecting the proximal end of the body to a connection port of the implantable pump.
