Aim. To analyze the results of valve-securing surgery on mitral valve in connective tissue dysplasia.Material and methods. From 2011 to 2014 y., totally 171 patient included, with isolated mitral regurgitation. Patients were randomized to 2 groups. Mean age in the Group D — ring, and Group C — flex, was 57 [42;65] and 54 [41;63] year old, respectively (p=0,092). Part of males was 69 and 67% in the groups, respectively.Results. There were no cases of 30-day mortality. During 24 months of follow-up, in D ring and C flex groups, survival was 96,0±2,3% (95% CI 88,6-98,7%) and 94,3±2,8% (95% CI 85,5- 97,9%), resp. (р=0,899); no re-operation — 97,0±2,1% (95% CI 88,4-99,3%) and 100%, resp. (р=0,044); no return of significant mitral regurgitation 80,8±6,5% (95% CI 64,0-90,3%) and 92,8±3,1% (95% CI 83,4-97,0%), resp. (р=0,002).Conclusion. Application of flexible C flex rings in valve-securing operations makes it to achieve better results in middle-long-term post-operation period comparing to the usage of semi-hard support rings in patients with connective tissue dysplasia and severe mitral regurgitation
