Intra-atrial insertion of a prosthetic mitral valve.

Infectious lesions of the mitral ring sometimes cause so much damage that insertion of the prosthesis in its normal place is impossible. In such cases, artificial valves with a dacron flange can be implanted into the left atrium, just above the mitral ring, and sutured to the atrial wall. These valves are generally used in first or second re-operations for recurrent desinsertion, but they have proved so reliable that their use can be extended to primary mitral valve replacement in cases where extreme calcification of the mitral ring throws considerable doubt on the success of conventional techniques.