Nuss bar procedure: past, present and future

Repair of pectus excavatum began at the beginning of the 20^th century before endotracheal intubation was standard practice. Surgeons therefore developed techniques that corrected the deformity using an open procedure via the anterior chest wall. Initial techniques were unsatisfactory, but by the 1930s the partial rib resection and sternal osteotomy technique had been developed and was used in combination with external traction post-operatively to prevent the sternum from sinking back into the chest. In 1949, Ravitch recommended complete resection of the costal cartilages and complete mobilization of the sternum without external traction, and in 1961 Adkins and Blades introduced the concept of a substernal strut for sternal support. The wide resection resulted in a very rigid anterior chest wall, and in some instances, the development of asphyxiating chondrodystrophy. The primary care physicians therefore became reluctant to refer the patients for repair. In 1987, Nuss developed a minimally invasive technique that required no cartilage or sternal resection and relied only on internal bracing by means of a sub-sternal bar, which is inserted into the chest through two lateral thoracic incisions and guided across the mediastinum with the help of thoracoscopy. After publication of the procedure in 1998, it became widely accepted and a flood of new patients suddenly started to appear, which allowed for rapid improvements and modifications of the technique. New instruments were developed specifically for the procedure, complications were recognized, and the steps taken to prevent them included the development of a stabilizer and the use of pericostal sutures to prevent bar displacement. Various options were developed for sternal elevation prior to mediastinal dissection to prevent injury to the mediastinal structures, allergy testing was implemented, and pain management improved. The increased number of patients coming for repair permitted studies of cardiopulmonary function, which showed that patients with a severe degree of pectus excavatum have right- sided cardiac compression, decreased filling, and decreased stroke volume. The degree of pulmonary restriction and obstruction is related to the degree of deformity and degree of cardiac displacement into the left chest. The indications for surgical repair have been clearly outlined, the procedure has been standardized, and post-operative management protocols are now available. A review of our prospective database showed that 98% of patients have a good to excellent outcome. This review of the "Past" outlines the progression of the surgical techniques during the 20^th century, the review of the "Present" outlines the important modifications and results of the closed technique, and the review of the "Future" outlines the various new options that are becoming available for the treatment of pectus excavatum.