Posterior leaflet augmentation in ischemic mitral regurgitation increases leaflet coaptation and mobility.
BACKGROUND
Restoring leaflet coaptation is the primary objective in repair of ischemic mitral regurgitation (IMR). The common practice of placing an undersized annuloplasty ring partially achieves this goal by correcting annular dilation; however, annular reduction has been demonstrated to exacerbate posterior leaflet tethering. Using a sheep model of IMR, we tested the hypothesis that posterior leaflet augmentation (PLA) combined with standard annuloplasty sizing increases leaflet coaptation more effectively than undersized annuloplasty alone.


METHODS
Eight weeks after posterobasal myocardial infarction, 15 sheep with 2+ or greater IMR underwent annuloplasty with either a 24-mm annuloplasty ring (24-mm group, n = 5), 30-mm ring (30-mm group, n = 5), or 30-mm ring with concomitant augmentation of the posterior leaflet (PLA group, n = 5). Using three-dimensional echocardiography, postrepair coaptation zone and posterior leaflet mobility were assessed.


RESULTS
Leaflet coaptation length after repair was greater in the PLA group (4.1 ± 0.3 mm) and the 24-mm group (3.8 ± 0.5 mm) as compared with the 30-mm group (2.7 ± 0.6 mm, p < 0.01). Leaflet coaptation area was significantly greater in the PLA group (121.5 ± 6.6 mm(2)) as compared with the 30-mm group (77.5 ± 17.0 mm(2)) or the 24-mm group (92.5 ± 17.9 mm(2), p < 0.01). Posterior leaflet mobility was significantly greater in the PLA group as compared with the 30-mm group or the 24-mm group.


CONCLUSIONS
Posterior leaflet augmentation combined with standard-sized annuloplasty enhances leaflet coaptation more effectively than either standard-sized annuloplasty or undersized annuloplasty alone. Increased leaflet coaptation after PLA provides redundancy to IMR repair, and may decrease incidence of both recurrent IMR and mitral stenosis.
Department of Surgery, University of Pennsylvania, Philadelphia, PA 19036, USA.
Arminder S
AS
Jassar
Masahito
M
Minakawa
Takashi
T
Shuto
J Daniel
JD
Robb
Kevin J
KJ
Koomalsingh
Melissa M
MM
Levack
Mathieu
M
Vergnat
Thomas J
TJ
Eperjesi
Benjamin M
BM
Jackson
Joseph H
JH
Gorman
Robert C
RC
Gorman
D000818:Animals; D007511:Ischemia / Q000601:surgery; D008943:Mitral Valve / Q000502:physiology* / Q000601:surgery*; D058386:Mitral Valve Annuloplasty / Q000379:methods*; D008944:Mitral Valve Insufficiency / Q000601:surgery*; D012756:Sheep