Pectus excavatum (PE), also known as funnel chest is by far the most common chest wall deformity. Pectus carinatum (PC), the next most common chest wall deformity, is less common than pectus excavatum. Treatment for pectus excavatum can involve either invasive or non-invasive techniques or a combination of both. The Ravitch technique is an invasive surgery. It involved creating an incision along the chest through which the cartilage is removed and the sternum detached. A small bar is then inserted underneath the sternum to hold it up in the desired position. The bar is left implanted until the cartilage grows back, typically about 6 months. The bar is subsequently removed in a simple out-patient procedure. This invasive procedure is often used in older patients, where the sternum has calcified, when the deformity is asymmetrical, or when the less invasive Nuss procedure has proven unsuccessful. The Nuss procedure is a technique that is minimally invasive. This procedure involves slipping in one or more concave steel bars into the chest, underneath the sternum. The bar is flipped to a convex position so as to push outward on the sternum, correcting the deformity. The bar usually stays in the body for about two years, although many surgeons are now moving toward leaving them in for longer. When the bones have solidified into place, the bar is removed through outpatient surgery. Both procedures are two-stage procedures.