Morphometric study of the human mitral annulus: guide for mitral valve surgery.

Background: during mitral valve surgery, it is important for surgeons to understand the anatomy of the mitral valve annulus to prevent surgical complications. This study aimed to perform morphometry of the mitral annulus to facilitate secure suturing during ring annuloplasty or replacement of the mitral valve.

Methods: an anatomical study was carried out on 7 human hearts. We divided the mitral valve annulus into sections containing 8 different points. It was noted that the annulus was a complex structure which has fibrous continuity with the mitral leaflets, and with or without the aortic annulus.

Results: there was always a segment of the annular fibrous structure which was facing directly toward the left ventricular cavity. The length of the segment ranged from 1.0 to 3.4 mm. In terms of the size of the annulus, there were large variations within the subject and among the subjects. The shortest distance between the mitral annulus and left circumflex coronary artery was at the anterolateral commissure, and the length was 3.3 mm.

Conclusion: this study has improved understanding of the anatomy of the mitral annulus, which could help surgeons to avoid operative complications. Based on this study, several suggestions are made for placing sutures for mitral valve replacement and mitral ring annuloplasty.