A negative pressure therapy unit is disclosed that is designed for healing internal wounds under the application of negative pressure. A plurality of tubes sequentially movable relative to one another are used to locate a filler material inside the organ. The tubes cover the filler material to avoid contact with the organ and filler material. A pressure tube passes internally to the plurality of tubes and communicates with the filler material. The filler material is in a compressed state between at least one of the plurality of tubes and the pressure tube. Translation of one of the plurality of tubes selectively exposes the filler material and permits the filler material to expand into the wound. The filler material is interchangeable on the wound and selectively on the pressure tube.
