Mitral Annular Remodeling to Treat Functional Mitral Regurgitation: A Pilot Acute Study in a Canine Model


  • Hideyuki Fumoto
  • Tohru Takaseya
  • Akira Shiose
  • Roberto M. Saraiva
  • Yoko Arakawa
  • Margaret Park
  • Santosh Rao
  • Raymond Dessoffy
  • Ji-Feng Chen
  • Qun Zhou
  • Anthony Calabro
  • Michael Banbury
  • Kiyotaka Fukamachi



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.


Byrne MJ, Kaye DM, Mathis M, Reuter DG, Alferness CA, Power JM. 2004. Percutaneous mitral annular reduction provides continued benefit in an ovine model of dilated cardiomyopathy. Circulation 110:3088-92.nDarr A, Calabro A. 2009. Synthesis and characterization of tyramine-based hyaluronan hydrogels. J Mater Sci Mater Med 20:33-44.nGrossi EA, Woo YJ, Schwartz CF, et al. 2006. Comparison of Coapsys annuloplasty and internal reduction mitral annuloplasty in the randomized treatment of functional ischemic mitral regurgitation: impact on the left ventricle. J Thorac Cardiovasc Surg 131:1095-8.nHerrmann HC, Rohatgi S, Wasserman HS, et al. 2006. Mitral valve hemodynamic effects of percutaneous edge-to-edge repair with the MitraClip device for mitral regurgitation. Catheter Cardiovasc Interv 68:821-8.nHung J, Solis J, Guerrero JL, et al. 2008. A novel approach for reducing ischemic mitral regurgitation by injection of a polymer to reverse remodel and reposition displaced papillary muscles. Circulation 118(suppl):S263-9.n[ILAR]Institute of Laboratory Animal Research, Commission on Life Sciences, National Research Council. 1996. Guide for the care and use of laboratory animals. Washington, DC: National Academies Press.nInoue M, McCarthy PM, Popovic ZB, et al. 2004. The Coapsys device to treat functional mitral regurgitation: in vivo long-term canine study. J Thorac Cardiovasc Surg 127:1068-76; discussion 1076-7.nKamohara K, Banbury M, Calabro A, et al. 2006. A novel technique for functional mitral regurgitation therapy: mitral annular remodeling. Heart Surg Forum 9:E888-92.nKuwahara E, Otsuji Y, Iguro Y, et al. 2006. Mechanism of recurrent/ persistent ischemic/functional mitral regurgitation in the chronic phase after surgical annuloplasty: importance of augmented posterior leaflet tethering. Circulation 114:I529-34.nManiu CV, Patel JB, Reuter DG, et al. 2004. Acute and chronic reduction of functional mitral regurgitation in experimental heart failure by percutaneous mitral annuloplasty. J Am Coll Cardiol 44:1652-61.nMcGee EC, Gillinov AM, Blackstone EH, et al. 2004. Recurrent mitral regurgitation after annuloplasty for functional ischemic mitral regurgitation. J Thorac Cardiovasc Surg 128:916-24.n



How to Cite

Fumoto, H., Takaseya, T., Shiose, A., Saraiva, R. M., Arakawa, Y., Park, M., Rao, S., Dessoffy, R., Chen, J.-F., Zhou, Q., Calabro, A., Banbury, M., & Fukamachi, K. (2010). Mitral Annular Remodeling to Treat Functional Mitral Regurgitation: A Pilot Acute Study in a Canine Model. The Heart Surgery Forum, 13(4), E247-E250.