SYSTEMS AND METHODS FOR EX VIVO ORGAN CARE
The invention, in various embodiments, provides systems, methods and solutions for perfusing an organ ex vivo.
1 . A method for evaluating a lung for transplant suitability comprising:
positioning the lung in an ex vivo perfusion circuit,
flowing a perfusion fluid into the lung through a pulmonary artery interface and flowing the perfusion fluid away from the lung through a pulmonary vein interface, the perfusion fluid being at a physiologic temperature,
providing a gas to the lung through a tracheal interface,
measuring a first composition of a gas component in the perfusion fluid, and
performing an evaluation on the lung based on the first composition.
2 . The method of claim 1 , wherein the perfusion fluid has a physiologic venous composition.
3 . The method of claim 1 , wherein the flow of the gas through the tracheal interface comprises about 100% oxygen.
4 . The method of claim 1 , wherein the flow of the gas through the tracheal interface comprises ambient air.
5 . The method of claim 1 , wherein the evaluation includes measuring a fractional inspired oxygen concentration.
6 . The method of claim 1 , wherein the evaluation includes measuring an arterial-venous (AV) oxygen gradient between the perfusion fluid flowing into the lung and the perfusion fluid flowing away from the lung.
7 . The method of claim 1 , wherein the evaluation includes measuring an alveolar arterial (AA) oxygen gradient.
8 . The method of claim 1 , wherein the evaluation includes measuring a tidal volume.
9 . The method of claim 1 , wherein the evaluation includes measuring at least one of a level of oxygen saturation of blood hemoglobin and a partial pressure of oxygen in the perfusion fluid flowing into the lung.
10 . The method of claim 1 , wherein the evaluation includes measuring at least one of a level of oxygen saturation of blood hemoglobin and a partial pressure of oxygen in the perfusion fluid flowing away from the lung.
11 . The method of claim 1 , wherein the evaluation includes measuring a positive end expiratory pressure.
12 . The method of claim 1 , comprising
measuring a saturation of oxygen in the perfusion fluid flowing through the pulmonary artery interface at a plurality of times during a period of testing,
measuring a saturation of oxygen in the perfusion fluid flowing through the pulmonary vein interface at the plurality of times during the period of testing,
comparing pulmonary artery and pulmonary vein oxygen saturation measurements at each of the plurality of times to determine comparative differences at the plurality of times, and
identifying a maximum difference among the comparative differences.
13 . The method of claim 12 , wherein the flow of the gas through the tracheal interface comprises about 100% oxygen.
14 . The method of claim 12 , wherein the flow of the gas through the tracheal interface is less than 100% oxygen.
15 . The method of claim 12 , wherein the flow of the gas through the tracheal interface is less than 75% oxygen.
16 . The method of claim 15 , wherein the flow of the gas through the tracheal interface is less than 50% oxygen.
17 . The method of claim 16 , wherein the flow of the gas through the tracheal interface is less than 25% oxygen.
18 . The method of claim 17 , wherein the flow of the gas through the tracheal interface contains no oxygen.
19 . The method of claim 1 , comprising applying a suction force through the tracheal interface to clear lung alveoli of debris.
20 . The method of claim 1 , comprising causing the lung to inhale breaths that are of variable volume to clear lung alveoli of debris.
21 . The method of claim 20 , wherein the breaths include a first breath having a volume that is larger than the volume of at least two next breaths.
22 . The method of claim 1 , comprising
adjusting a composition of the flow of gas to the lung after measuring the first composition of the gas component,
measuring a second composition of the gas component in the perfusion fluid after adjusting the composition of the flow of gas;
comparing the measurements of the first and second compositions of the gas component; and
performing the evaluation based on the comparison.