Annular and Sub-Valvular Repair Techniques for Ischemic Mitral Regurgitation: In-

Summary

Principal Investigator: AJIT P contact YOGANATHAN
Abstract: Approximately 7.9 million Americans suffer from heart failure every year. Among these, nearly 2.5 million develop Ischemic Mitral Regurgitation (IMR), a 33% increase since 1995. Even with such high prevalence, little is known of the cause and progression of chronic IMR, resulting in the current lack of effective medical options for these patients. What is known for certain is that IMR is secondary to gross three dimensional geometric alterations of the patient's Left Ventricle (LV), resulting in alterations in the geometry of the Mitral Valve (MV). Present surgical repair techniques to restore native LV and MV geometries lack satisfactory long-term patient outcomes. Consequently, long-term survival rates for IMR are poor and worse as compared to many types of cancer. The most important reason for the poor outcome is the lack of knowledge of the exact 3D geometric alterations of the patient's MV responsible for IMR, without which appropriate surgical treatment is not possible. The objective of this proposal is to delineate and understand the geometric distortions of the MV that lead to IMR and develop appropriate repair procedures that can be directly translated to clinical practice in the near future. The central hypothesis driving our long objectives is: Ischemic Mitral Regurgitation is strongly related to geometric alterations of the native mitral valve at the annular and/or sub-valvular levels. Understanding these alterations will clarify the geometric determinants of Ischemic Mitral Regurgitation and will help in designing better and efficient repair procedures thus leading to better surgical outcomes. Our hypothesis has been formulated based on strong preliminary data produced in our laboratories at Georgia Tech and the University of Pennsylvania. The proposed study consists of a sophisticated methodology combining in-vitro and in-vivo approaches to design an efficient IMR model that can not only test the hypothesis but also develop novel surgical approaches. The in-vivo model of IMR though effective is very reproducible and mimics only one representation of the human IMR disease. The in-vitro IMR model is a versatile model that provides precise control over the geometric distortions imposed on the valve. Also, the in-vitro model will be a potential test-bed with additional studies (beyond the currently proposed 2 year experiments) for developing novel MV surgical repair techniques that may be easily translated to clinical practice.
Funding Period: ----------------2009 - ---------------2011-
more information: NIH RePORT

Top Publications

  1. pmc Dynamic assessment of mitral annular force profile in an ovine model
    Andrew W Siefert
    The Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, USA
    Ann Thorac Surg 94:59-65. 2012
  2. pmc Comparison of artificial neochordae and native chordal transfer in the repair of a flail posterior mitral leaflet: an experimental study
    Muralidhar Padala
    Structural Heart Disease Research and Innovation Laboratory, Carlyle Fraser Heart Center, Division of Cardiothoracic Surgery, Emory University, Atlanta, Georgia, USA
    Ann Thorac Surg 95:629-33. 2013
  3. pmc In vitro mitral valve simulator mimics systolic valvular function of chronic ischemic mitral regurgitation ovine model
    Andrew W Siefert
    The Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, USA
    Ann Thorac Surg 95:825-30. 2013
  4. pmc Accuracy of a mitral valve segmentation method using J-splines for real-time 3D echocardiography data
    Andrew W Siefert
    Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 313 Ferst Dr, Atlanta, GA 30332, USA
    Ann Biomed Eng 41:1258-68. 2013
  5. pmc In vitro comparison of Doppler and catheter-measured pressure gradients in 3D models of mitral valve calcification
    Tarrah A Herrmann
    The Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30332, USA
    J Biomech Eng 135:94502. 2013
  6. pmc In-vivo mitral annuloplasty ring transducer: implications for implantation and annular downsizing
    Andrew W Siefert
    The Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 313 Ferst Drive, Atlanta, GA 30332, USA
    J Biomech 46:2550-3. 2013
  7. ncbi Isolated effect of geometry on mitral valve function for in silico model development
    Andrew William Siefert
    a The Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 311 Ferst Dr, Atlanta, GA 30332, USA
    Comput Methods Biomech Biomed Engin 18:618-27. 2015

Detail Information

Publications9

  1. pmc Dynamic assessment of mitral annular force profile in an ovine model
    Andrew W Siefert
    The Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, USA
    Ann Thorac Surg 94:59-65. 2012
    ..Determining the peak magnitudes, directions, rates, variation throughout the cardiac cycle, and change with left ventricular pressure (LVP) will aid in device development and evaluation...
  2. pmc Comparison of artificial neochordae and native chordal transfer in the repair of a flail posterior mitral leaflet: an experimental study
    Muralidhar Padala
    Structural Heart Disease Research and Innovation Laboratory, Carlyle Fraser Heart Center, Division of Cardiothoracic Surgery, Emory University, Atlanta, Georgia, USA
    Ann Thorac Surg 95:629-33. 2013
    ..In this study, we sought to investigate the efficacy of the 2 techniques to correct posterior leaflet prolapse and reduce mitral regurgitation, and quantify the acute post repair leaflet kinematics...
  3. pmc In vitro mitral valve simulator mimics systolic valvular function of chronic ischemic mitral regurgitation ovine model
    Andrew W Siefert
    The Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, USA
    Ann Thorac Surg 95:825-30. 2013
    ....
  4. pmc Accuracy of a mitral valve segmentation method using J-splines for real-time 3D echocardiography data
    Andrew W Siefert
    Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 313 Ferst Dr, Atlanta, GA 30332, USA
    Ann Biomed Eng 41:1258-68. 2013
    ..Results demonstrate the accuracy of a MV segmentation methodology for the development of future surgical planning tools...
  5. pmc In vitro comparison of Doppler and catheter-measured pressure gradients in 3D models of mitral valve calcification
    Tarrah A Herrmann
    The Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30332, USA
    J Biomech Eng 135:94502. 2013
    ..Determining these end points will contribute to greater clinical understanding for the diagnosis MAC patients and understanding the use and application of Doppler echocardiography to estimate transmitral pressure gradients. ..
  6. pmc In-vivo mitral annuloplasty ring transducer: implications for implantation and annular downsizing
    Andrew W Siefert
    The Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 313 Ferst Drive, Atlanta, GA 30332, USA
    J Biomech 46:2550-3. 2013
    ..Upon additional investigation, these data will contribute to improved knowledge of annulus-ring stresses, LV function, and the safer development of mitral repair techniques...
  7. ncbi Isolated effect of geometry on mitral valve function for in silico model development
    Andrew William Siefert
    a The Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 311 Ferst Dr, Atlanta, GA 30332, USA
    Comput Methods Biomech Biomed Engin 18:618-27. 2015
    ..This novel data may improve MV computational models and provide a platform for the development of future surgical planning tools. ..