Re-sternotomy as an unwelcome side-effect of unknown effervescent tablet intake?

Four hours after surgery for aortic valve stenosis and tricuspid valve regurgitation, an unknown foreign body was present on the routine chest X-ray. We performed re-sternotomy in order to retrieve this foreign body. The foreign body was easy to move on fluoroscopy but we could not extract it. We concluded that the foreign body was in a subdiaphragmatic location. As a consequence, we performed gastroscopy. A white, frothy mass (similar to an undissolved effervescent tablet) within an ulcerated lesion was seen and partially extracted.