Septal-lateral annular cinching abolishes acute ischemic mitral regurgitation.
OBJECTIVE
Ring annuloplasty prevents acute ischemic mitral regurgitation in sheep, but it also abolishes normal mitral annular and posterior leaflet dynamics. We investigated a novel surgical approach of simple septal-lateral annular cinching with sutures to treat acute ischemic mitral regurgitation.


METHODS
Nine adult sheep underwent implantation of multiple radiopaque markers on the left ventricle, mitral anulus, and mitral leaflets. A septal-lateral transannular suture was anchored to the midseptal mitral anulus and externalized to a tourniquet through the midlateral mitral anulus and left ventricular wall. Open-chest animals were studied immediately postoperatively. Acute ischemic mitral regurgitation was induced by means of proximal left circumflex artery snare occlusion, and 3 progressive steps of septal-lateral annular cinching (each 2-3 mm suture tightening for 5 seconds) were performed with the transannular suture. Biplane videofluoroscopy for 3-dimensional marker coordinates and transesophageal echocardiography were performed continuously before and during left circumflex ischemia and septal-lateral annular cinching.


RESULTS
Acute left circumflex ischemia caused ischemic mitral regurgitation (+0.5 +/- 0.4 [baseline] vs +2.0 +/- 0.7 [ischemia]; P =.005; scale, +0-4), which decreased progressively with each step of septal-lateral annular cinching and was eliminated during the third step (ischemic mitral regurgitation, +0.6 +/- 0.5; P = not significant vs baseline). The third step of septal-lateral annular cinching decreased the septal-lateral diameter by 6.0 +/- 2.6 mm (P =.005); however, mitral anulus area reduction (8.5% +/- 1.0% and 6.9% +/- 1.9% for ischemic mitral regurgitation and septal-lateral annular cinching step 3, respectively; P =.006) and posterior leaflet excursion (50 degrees +/- 9 degrees and 44 degrees +/- 11 degrees for regurgitation and annular cinching step 3, respectively; P =.002) throughout the cardiac cycle were affected only mildly. Normal mitral annular 3-dimensional shape was maintained with septal-lateral annular cinching.


CONCLUSIONS
Isolated 22% +/- 10% reduction in mitral annular septal-lateral dimension abolished acute ischemic mitral regurgitation in normal sheep hearts while allowing near-normal mitral annular and posterior leaflet dynamic motion. Septal-lateral annular cinching may represent a simple method for the surgical treatment of ischemic mitral regurgitation, either as an adjunctive technique or alone, which helps preserve physiologic annular and leaflet function.
Timek
Tomasz A
TA
Department of Cardiovascular Surgery and the Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, Calif, USA.
Lai
David T
DT
Tibayan
Frederick
F
Liang
David
D
Daughters
George T
GT
Dagum
Paul
P
Ingels
Neil B
NB
Miller
D Craig
DC
D000208:Acute Disease; D000704:Analysis of Variance; D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D019918:Heart Valve Prosthesis Implantation; D006439:Hemodynamics / Q000502:physiology; D008297:Male; D008943:Mitral Valve / Q000503:physiopathology / Q000601:surgery*; D008944:Mitral Valve Insufficiency / Q000503:physiopathology / Q000601:surgery*; D017202:Myocardial Ischemia / Q000150:complications / Q000601:surgery*; D011336:Probability; D012680:Sensitivity and Specificity; D012756:Sheep; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology