An ischemic postconditioning system and related method comprising a catheter including a plurality of lumens and at least one expandable member with at least one chamber including a moveable plunger and a return mechanism operatively engaged with the plunger. The moveable plunger divides the at least one chamber into first and second volumes. A first pressure source is provided having a first fluid at a first pressure and is disposed in fluid communication with the first volume of the chamber. Further, a second pressure source is provided having a second fluid at a second pressure and is disposed in fluid communication with the second volume of the chamber. Similarly, the at least one expandable member is disposed in fluid communication with the second volume of the chamber. The first fluid supplied by the first pressure source displaces the plunger in a first direction delivering at least a portion of the second fluid into the at least one expandable member. Also, the return mechanism displaces the plunger in a second direction delivering the second fluid from the second pressure source to the second volume of the chamber.