Does septal-lateral annular cinching work for chronic ischemic mitral regurgitation?
OBJECTIVE
Ring annuloplasty, the current treatment of choice for chronic ischemic mitral regurgitation, abolishes dynamic annular motion and immobilizes the posterior leaflet. In a model of chronic ischemic mitral regurgitation, we tested septal-lateral annular cinching aimed at maintaining normal annular and leaflet dynamics.


METHODS
Twenty-five sheep had radiopaque markers placed on the mitral annulus and anterior and posterior mitral leaflets. A transannular suture was anchored to the midseptal mitral annulus and externalized through the midlateral mitral annulus. After 7 days, biplane cinefluoroscopy provided 3-dimensional marker data (baseline) prior to creating inferior myocardial infarction by snare occlusion of obtuse marginal branches. After 7 weeks, the 9 animals that developed chronic ischemic mitral regurgitation were restudied before and after septal-lateral annular cinching. Anterior and posterior mitral leaflet angular excursion and annular septal-lateral and commissure-commissure dimensions and percent shortening were computed.


RESULTS
Septal-lateral annular cinching reduced septal-lateral dimension (baseline: 3.0 +/- 0.2; chronic ischemic mitral regurgitation: 3.5 +/- 0.4 [P <.05 vs baseline by repeated measures analysis of variance and Dunnett's test]; septal-lateral annular cinching: 2.4 +/- 0.3 cm; maximum dimension) and eliminated chronic ischemic mitral regurgitation (baseline: 0.6 +/- 0.5; chronic ischemic mitral regurgitation: 2.3 +/- 1.0 [P <.05 vs baseline by repeated measures analysis of variance and Dunnett's test]; septal-lateral annular cinching: 0.6 +/- 0.6; mitral regurgitation grade [0 to 4+]) but did not alter dynamic annular shortening (baseline: 7 +/- 3; chronic ischemic mitral regurgitation: 10 +/- 5; septal-lateral annular cinching: 6 +/- 2, percent septal-lateral shortening) or posterior mitral leaflet excursion (baseline: 46 degrees +/- 8 degrees; chronic ischemic mitral regurgitation: 41 degrees +/- 13 degrees; septal-lateral annular cinching: 46 degrees +/- 8 degrees ).


CONCLUSIONS
In this model, septal-lateral annular cinching decreased chronic ischemic mitral regurgitation, reduced annular septal-lateral diameter (but not commissure-commissure diameter), and maintained normal annular and leaflet dynamics. These findings provide additional insight into the treatment of chronic ischemic mitral regurgitation.
Division of Cardiovascular and Thoracic Surgery, Stanford University School of Medicine, Stanford, CA 94305-5247, USA.
Frederick A
FA
Tibayan
Filiberto
F
Rodriguez
Frank
F
Langer
Mary K
MK
Zasio
Lynn
L
Bailey
David
D
Liang
George T
GT
Daughters
Neil B
NB
Ingels
D Craig
DC
Miller
D000818:Animals; D006348:Cardiac Surgical Procedures / Q000379:methods; D002908:Chronic Disease; D017548:Echocardiography, Transesophageal; D006439:Hemodynamics; D008943:Mitral Valve / Q000503:physiopathology / Q000601:surgery*; D008944:Mitral Valve Insufficiency / Q000209:etiology / Q000503:physiopathology / Q000601:surgery*; D009200:Myocardial Contraction; D017202:Myocardial Ischemia / Q000150:complications*; D012756:Sheep; D013536:Suture Techniques