Abstract
Although sizing for mitral annuloplasty (MAP) is a critical part of mitral valve repair, no consistent method is used, and precise size adjustment is done somewhat by intuition. We developed a new original ring size tester and have been applying it to our mitral valve repair procedure. The concept is that the tester shapes the annulus into exactly the same size and form as the target annuloplasty while confirming a good leaflet coaptation with a saline test to simulate annuloplasty. This original tester provides the best ring size for MAP that is neither too large nor too small. In this paper, we introduce our original ring size tester and describe how it is used for MAP.