An adhesion is a band of scar tissue that binds two parts of tissue that are not normally joined together. Adhesions may appear as thin sheets of tissue similar to plastic wrap or as thick fibrous bands. The tissue develops when the body's repair mechanisms respond to any tissue disturbance, such as surgery, infection, trauma, or radiation. Although adhesions can occur anywhere, the most common locations are within the stomach, the pelvis, and the heart Two main approaches exist for reducing or attempting to prevent cardiac adhesions: pharmacological therapy and physical barriers. Drugs that prevent or reverse adhesion processes disrupt biochemical pathways of inflammation and fibrin deposition. Unfortunately, these processes are also vital for wound healing. Achieving adequate drug concentration at the site of action, especially for ischemic tissues, is also challenging. A more viable approach is the use of a physical barrier after surgery to prevent fusion of the heart to surrounding tissues. The barriers can be either preformed membranes or injectable hydrogels (fast gelling liquids). Preformed anti-adhesive materials need to be cut before application to the tissue, and must be sutured into place to prevent slippage. While a variety of different materials have been investigated in animals and humans, no materials, to date, have been capable of preventing adhesion formation post-cardiac surgery.