Mitral annular remodeling to treat functional mitral regurgitation: a pilot acute study in a canine model.
BACKGROUND
The aim of this study was to evaluate the feasibility and efficacy of the injection of a nonabsorbable substance into the base of the left ventricle (LV) to treat functional mitral regurgitation (MR).


METHODS
Tyramine-based hyaluronan hydrogel was injected into the base of the LV of the beating heart in a canine model of rapid ventricular pacing-induced functional MR (n = 4). The severity of MR was evaluated by epicardial echocardiography before and after hydrogel injection.


RESULTS
The injection improved MR grade from 3.4 +/- 0.8 to 1.3 +/- 0.5 (P = .006) without inducing hemodynamic instability or any evidence of myocardial ischemia. We noted significant decreases in the septal-lateral dimension at the mitral annulus (3.4 +/- 0.4 cm to 2.9 +/- 0.3 cm; P = .039) and MR volume (20.6 +/- 7.3 mm3 to 5.2 +/- 2.2 mm3; P = .044).


CONCLUSIONS
A novel treatment consisting of hydrogel injection into the base of the LV between the 2 papillary muscles was found to be feasible and effective for reducing functional MR in a canine model.
Fumoto
Hideyuki
H
Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA.
Takaseya
Tohru
T
Shiose
Akira
A
Saraiva
Roberto M
RM
Arakawa
Yoko
Y
Park
Margaret
M
Rao
Santosh
S
Dessoffy
Raymond
R
Chen
Ji-Feng
JF
Zhou
Qun
Q
Calabro
Anthony
A
Banbury
Michael
M
Fukamachi
Kiyotaka
K
D000818:Animals; D004285:Dogs; D004452:Echocardiography; D005240:Feasibility Studies; D006352:Heart Ventricles; D006820:Hyaluronic Acid / Q000008:administration & dosage*; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000008:administration & dosage*; D007273:Injections, Intramuscular; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000628:therapy*; D010210:Papillary Muscles; D010865:Pilot Projects; D011184:Postoperative Period; D012720:Severity of Illness Index; D016896:Treatment Outcome
D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D006820:Hyaluronic Acid