A novel technique for functional mitral regurgitation therapy: mitral annular remodeling.
BACKGROUND
Functional mitral regurgitation (AIR) plays a pivotal role in the pathophysiology of congestive heart failure, a major cause of cardiac morbidity and mortality. We have developed a mitral annular remodeling procedure through injection of a nonabsorbable substance into the peri-annular tissue of the posterior mitral annulus to reduce the mitral annular dimension in the septal-lateral axis. The purpose of this study is to describe a novel procedure for treatment of functional AIR and report its effects on the geometry of the mitral annulus and degree of AIR.


METHODS
Seven preliminary studies were performed using an epicardial approach in a healthy dog model to establish the feasibility of this injection procedure. Unexpectedly, 2 of 7 healthy dogs had a functional AIR of grade 1 to 2+. In these 2 cases, the hemodynamic, angiographic, and echocardiographic assessments were conducted.


RESULTS
A nonabsorbable substance injection was successfully performed on a beating heart without instability of hemodynamics or any evidence of myocardial ischemia in all 7 dogs. In the 2 dogs with a functional AIR, it was confirmed that the septal-lateral dimension decreased from 3.2 +/- 0.2 to 2.6 +/- 0.5 cm and the observed MR was reduced (AIR area from 1.2 +/-0.1 to 0 cm2) without any adverse effects on hemodynamics or coronary circulation (circumflex artery flow, 36.5 +/- 0.4 to 40.5 +/- 0.1 mL/min).


CONCLUSIONS
Off-pump mitral annular remodeling through substance injection may be one procedural option for treatment of functional AIR.
Kamohara
Keiji
K
Department of Biomedical Engineering, Lerner Research Institute, Cleveland, Ohio, USA.
Banbury
Michael
M
Calabro
Anthony
A
Popović
Zoran B
ZB
Darr
Aniq
A
Ootaki
Yoshio
Y
Akiyama
Masatoshi
M
Cingoz
Faruk
F
Ootaki
Chiyo
C
Kopcak
Michael W
MW
Dessoffy
Raymond
R
Liu
Jenny
J
Fukamachi
Kiyotaka
K
D000276:Adjuvants, Immunologic / Q000008:administration & dosage*; D000818:Animals; D004285:Dogs; D006820:Hyaluronic Acid / Q000008:administration & dosage*; D007267:Injections; D008943:Mitral Valve / Q000473:pathology*; D008944:Mitral Valve Insufficiency / Q000628:therapy*
D000276:Adjuvants, Immunologic; D006820:Hyaluronic Acid