Pectus excavatum is the most common congenital chest wall abnormality in children. Surgical correction requires a big and often brutal operation under general anesthesia which forces the sternum forward and holds it in place using a metal chest wall strut. Deformation of the chest wall under great pressure results in complications and relapses as well as postoperative pain requiring hospitalization for regional and narcotic anesthesia for up to a week and pain and disability for weeks or months. A better principle for correction of chest wall and other deformities is gradual correction using minimal force applied over many months (like moving teeth with orthodontic braces). The applicant is developing a novel method of achieving gradual deformation/reformation of chest wall cartilage without the need for transdermal orthopedic devices or repeated surgeries. A magnetic force field is used to apply controlled, intermittent force to promote biologic reformation of structural cartilage (the same principle as distraction osteogenesis). A magnet is implanted under the sternum and secured using a fixation strategy that can be accomplished through a 3-cm subzyphoid incision as a brief outpatient procedure. The magnet (and sternum) is pulled outward by another magnet suspended in a low-profile, lightweight device previously molded to the patient's anterior chest wall. The external magnet suspended from four independent strain gauges measures the magnetic force generated and allows individual adjustment in small increments of the distance and orientation of the force applied to the sternum. The low-profile, non-obstrusive anterior chest wall prosthesis is held in place by the force field between the two magnets. The applicant will test the safety and probable benefit of this procedure/device in 10 otherwise healthy patients and document the rate of correction by monthly laser scan and the end result by change in pectus severity index (from chest X-ray). If successful, an application for Humanitarian Use Device designation will be submitted to make the treatment available under Humanitarian Device Exemption.
