The quality of the repair should first be evaluated after tying the ring sutures. Saline is injected into the ventricular cavity through the mitral valve. A symmetrical line of coaptation, parallel to the posterior part of the ring, with a normal ¾ to ¼ ratio of anterior to posterior leaflet within the orifice should be confirmed. An asymmetrical line of coaptation suggests the presence of residual leaflet prolapse or restricted leaflet motion, which should be corrected. If the posterior leaflet occupies half or more of the ring orifice area, it should be shortened to minimize the risk of SAM.
If the saline test is normal then the next assessment occurs at the completion of cardiopulmonary bypass by transesophageal echocardiographic assessment. Residual regurgitation or valvular dysfunction should lead to a second bypass run with re-inspection of the line of closure and correction of residual lesions.