Correction of the Manubriosternal Angle: The Missing Link in the Diagnosis and Management of Anterior Chest Wall “Pectus” Deformities

Abstract

A normal manubriosternal angle (MSA) varies between 157 and 161 degrees, and it is either increased (in pectus carinatum) or decreased (in pectus excavatum). Measurements of the MSA can accurately define the severity of both deformities and gauge the degree of response to therapeutic intervention(s). Correction of the MSA during repair of pectus deformity by complete upper transverse sternotomy seems necessary. We found no report of complete upper transverse sternotomy in repairing pectus deformities. Similarly, the MSA was never used in defining the severity of pectus deformity. We describe a novel technique in repairing anterior chest wall deformity (pectus carinatum, MSA = 172) in a young man. Under general anesthesia and complete aseptic precautions, through a midline presternal incision, bilateral pectoral flaps were mobilized, and complete transverse sternotomy at the level of the second intercostal space and bilateral intrapericondrium excision of the costal cartilages (3-7) were performed. The wound was closed in layers after insertion of two, 9-mm subpectoral Redivac drains. The patient had an uneventful recovery with satisfactory cosmetic appearance. Magnetic resonance imaging of the chest 4 months postoperatively showed reduction of the MSA by 8 degrees, which is 78% (8 of 11) progress toward reaching the upper limit of normal MSA values. In correcting pectus deformity, complete transaction of the sternum at the level of the second intercostal space enhances recovery and allows for normalization of the MSA. Using the MSA in assessing the severity and response to treatment of pectus deformity is recommended.