The surgical problems involved in the treatment for concretio cordis are distinctly different from those involved in the treatment for mediastinopericarditis. In mediastinopericarditis, the main indication is relief from interference with the systolic contractions of the heart. Relief is most easily and efficiently obtained by resecting the bony and cartilaginous structures of the thoracic wall in the area overlying the heart, a procedure described by Brauer. In concretio cordis, the thickened pericardium contracts about the heart and prevents adequate filling of the cardiac chambers during diastole. In some cases there are adhesions between the thickened pericardium and the surrounding structures, while in others the pericardial walls are calcified or are so greatly thickened that the systolic contractions of the heart are seriously interfered with. In any case, the primary difficulty is with diastole, and relief can be expected only from a release of the heart by removal of the constricting