Impact of papillary muscle relocation as adjunct procedure to mitral ring annuloplasty in functional ischemic mitral regurgitation.
BACKGROUND
The optimal surgical treatment in functional ischemic mitral regurgitation (FIMR) remains controversial. Recently, a posterior papillary muscle relocation (PMR) technique as adjunct procedure to ring annuloplasty has been proposed to prevent recurrent FIMR. In the present study, we used 3D cardiac MRI to assess the impact of relocating both papillary muscles as adjunct procedure to downsized ring annuloplasty on mitral leaflet coaptation geometry in FIMR pigs.


RESULTS
Eleven FIMR pigs were randomized to downsized ring annuloplasty (RA; n=6) or RA combined with PMR (RA+PMR, n=5). In the RA+PMR group, a 2-0 Gore-Tex suture was attached to each trigone, exteriorized through the corresponding papillary muscle, mounted on an epicardial pad, and tightened to relocate the myocardium adjacent to the anterior and posterior papillary muscles 5 and 15 mm, respectively. Using 3D MRI, the impact from these interventions on leaflet geometry was assessed. The distance from the posterior papillary muscle to the anterior trigone was reduced significantly more (median values) in the RA+PMR compared with RA animals at end-diastole (-7.9% versus 3.8%, P<0.01) and end-systole (-9.7% versus 2.5%, P=0.02). Accordingly, lateral tethering of the coaptation point (median values) was reduced significantly more in RA+PMR compared with RA animals (-42.8% versus -29.1%, P<0.01).


CONCLUSIONS
Adding papillary muscle relocation to downsized ring annuloplasty reduced lateral leaflet tethering in a porcine experimental model of FIMR. Therefore, this technique holds promise for reducing persistent and recurrent FIMR in patients.
Jensen
Henrik
H
Department of Cardiothoracic and Vascular Surgery T, Aarhus University Hospital-Skejby, Denmark. hjensen@dadlnet.dk
Jensen
Morten O
MO
Smerup
Morten H
MH
Vind-Kezunovic
Stefan
S
Ringgaard
Steffen
S
Andersen
Niels T
NT
Vestergaard
Rikke
R
Wierup
Per
P
Hasenkam
J Michael
JM
Nielsen
Sten L
SL
D000818:Animals; D008943:Mitral Valve / Q000601:surgery*; D008944:Mitral Valve Insufficiency / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D017202:Myocardial Ischemia / Q000150:complications*; D010210:Papillary Muscles / Q000601:surgery*; D013552:Swine; D016277:Ventricular Function, Left; D020257:Ventricular Remodeling