Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The pigtail catheter has been removed since the prior exam , and in the interim , a moderate left pleural effusion has not appreciably changed in size . The patient is status post median sternotomy with valve replacement . The right lung is clear . There is no pneumothorax .
    OUTPUT:
    
Status post left pigtail catheter removal with no significant interval change in chronic moderate left pleural effusion .