The PK Papyrus Covered Coronary Stent System is a Humanitarian Use device (HUD) approved for the use of acute perforation in native coronary vessels or coronary bypass grafts in vessels 2.4-5.0mm in diameter. In an emergency situation, PK Papyrus may be used emergently outside its' approved indications if a patient has a life threatening condition that needs immediate treatment and no generally acceptable alternative treatment for the condition exists.