Subvalvular repair: the key to repairing ischemic mitral regurgitation?
BACKGROUND
Residual or recurrent mitral regurgitation frequently occurs after mitral ring annuloplasty repair for ischemic mitral regurgitation (IMR), because annuloplasty primarily addresses annular dilatation. We describe a subvalvular repair technique addressing posterior papillary muscle (PPM) displacement.


RESULTS
Ten sheep had radiopaque markers placed on the left ventricle (LV) and mitral apparatus. A suture was anchored at the right fibrous trigone, passed through the PPM tip and LV wall, and exteriorized through a tourniquet (STRING-1). A second suture was anchored transmurally in the high septum (anterobasal LV wall) and passed through the PPM and LV wall (STRING-2). Reversible posterolateral ischemia was induced by temporarily occluding the proximal circumflex artery. Under open chest conditions, 3D marker coordinates were obtained with biplane videofluoroscopy at baseline and during acute ischemia before and after tightening of each STRING using transesophageal echocardiography to grade IMR. IMR decreased (mean+/-SEM, 2.0+/-0.1 to 1.2+/-0.1; P<0.05) when STRING-1 was tightened, did not change after tightening STRING-2 (2.3+/-0.1 to 2.3+/-0.1), and decreased after tightening both sutures (STRING-1+2, 2.3+/-0.2 to 1.3+/-0.2; P<0.05). STRING-1 and STRING-1+2 (STRING-1, 1.7+/-0.4 mm; STRING-2, 0.7+/-0.5 mm; STRING-1+2, 1.5+/-0.3 mm; P<0.05) resulted in significant PPM basal repositioning. Tightening of any STRING sutures did not affect anterior mitral leaflet excursion.


CONCLUSIONS
Basal repositioning of the PPM with STRING-1 reduced acute IMR without concomitant annular reduction. This technique may be a useful adjunct if residual IMR is likely after undersized ring annuloplasty.
Langer
Frank
F
Department of Cardiothoracic Surgery, Stanford University School of Medicine, 300 Pasteur Dr, Stanford, CA 94305, USA.
Rodriguez
Filiberto
F
Ortiz
Saskia
S
Cheng
Allen
A
Nguyen
Tom C
TC
Zasio
Mary K
MK
Liang
David
D
Daughters
George T
GT
Ingels
Neil B
NB
Miller
D Craig
DC
D000208:Acute Disease; D000818:Animals; D006328:Cardiac Catheterization; D004195:Disease Models, Animal; D005471:Fluoroscopy; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D008944:Mitral Valve Insufficiency / Q000209:etiology / Q000473:pathology / Q000601:surgery*; D009038:Motion; D017202:Myocardial Ischemia / Q000150:complications*; D010210:Papillary Muscles / Q000000981:diagnostic imaging / Q000473:pathology; D012756:Sheep; D013536:Suture Techniques; D014741:Video Recording