The stomach resides in the abdominal cavity. A hiatus hernia is when part or all of your stomach moves into the chest cavity, and lie next to your heart and lungs. Sometimes other organs such as your colon, can herniate into the chest cavity along with your stomach. This can lead to complications such as gastric reflux, difficulty eating food, breathing difficulties or twisting of the stomach. If your stomach becomes twisted, it may lose its blood supply and require emergency surgery.
There are 4 main types of hiatus hernias, as shown in the image.
Image courtesy of Adult Chest Surgery 2nd Ed.
Repairing the hiatus hernia is usually performed laparoscopically (keyhole surgery). The stomach and other contents of the hernia need to me pulled back down from the chest into the abdomen. The repair may require the use of a dissolvable mesh in order to stengthen the repair. A fundoplication (click here for more information) is also performed as part of the repair.