Anterior mitral leaflet curvature in the beating ovine heart: a case study using videofluoroscopic markers and subdivision surfaces
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The implantation of annuloplasty rings is a common surgical treatment targeted to re-establish mitral valve competence in patients with mitral regurgitation. It is hypothesized that annuloplasty ring implantation influences leaflet curvature, which in turn may considerably impair repair durability. This research is driven by the vision to design repair devices that optimize leaflet curvature to reduce valvular stress. In pursuit of this goal, the objective of this manuscript is to quantify leaflet curvature in ovine models with and without annuloplasty ring using in vivo animal data from videofluoroscopic marker analysis. We represent the surface of the anterior mitral leaflet based on 23 radiopaque markers using subdivision surfaces techniques. Quartic box-spline functions are applied to determine leaflet curvature on overlapping subdivision patches. We illustrate the virtual reconstruction of the leaflet surface for both interpolating and approximating algorithms. Different scalar-valued metrics are introduced to quantify leaflet curvature in the beating heart using the approximating subdivision scheme. To explore the impact of annuloplasty ring implantation, we analyze ring-induced curvature changes at characteristic instances throughout the cardiac cycle. The presented results demonstrate that the fully automated subdivision surface procedure can successfully reconstruct a smooth representation of the anterior mitral valve from a limited number of markers at a high temporal resolution of approximately 60 frames per minute.
KeywordsMitral valve Mitral regurgitation Annuloplasty ring Curvature Subdivision surfaces Continuity
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- Bothe W, Krishnamurthy G, Chang PA, Swanson JC, Briones EP, Davis LR, Itoh A, Ingels NB, Miller CD (2009) Effects of the Geoform® annuloplasty ring on anterior mitral leaflet strains and stresses in the normal ovine heart (submitted for publication)Google Scholar
- Cosgrove D (2004) Review: view from North America’s cardiac surgeons. Eur J Cardiothorac Surg 26: S27–S31Google Scholar
- Daughters G, Sanders W, Miller DC, Schwarzkopf A, Mead C, Ingels NB (1989) A comparison of two analytical systems for 3-D reconstruction from biplane videoradiograms. IEEE Comput Cardiol 15: 79–82Google Scholar
- Karlsson MO, Glasson JR, Daughters GT, Komeda M, Foppiano LE, Miller DC, Ingels NB (1998) Mitral valve opening in the ovine heart. Am J Physiol Heart Circ Physiol 274: H552–H563Google Scholar
- Kreyszig E (1991) Differential geometry. Dover, New YorkGoogle Scholar
- Krishnamurthy G, Itoh A, Swanson J, Bothe W, Karlsson M, Kuhl E, Miller DC, Ingels NB (2009) Regional stiffening of the mitral valve anterior leaflet in the beating ovine heart. J Biomech. doi:10.1016/j.jbiomech.2009.08.028
- Loop C (1987) Smooth subdivision surfaces based on triangles. Masters Thesis, University of Utah, Department of MathematicsGoogle Scholar