title: Exploring better methods to preserve the chordae tendineae during mitral valve replacement.
abstract: BACKGROUND
  It is not known how best to resuspend the mitral chordae tendineae during mitral valve replacement to optimize postoperative left ventricular (LV) systolic and diastolic function.
  
  
  METHODS
  Six different techniques to preserve the chordae during mitral valve replacement were compared in 12 dogs using a nondistorting isovolumic technique: conventional, all chordae severed; anterior, all chordae preserved anteriorly; partial, anterior papillary muscle chordae preserved anteriorly; posterior, all chordae preserved posteriorly; oblique, anterior papillary muscle chordae directed anteriorly and posterior papillary muscle chordae posteriorly; and counter, opposite of oblique chordal direction. Control measurements (no chordal tension) were recorded between each experimental condition.
  
  
  RESULTS
  The oblique method tended to have the best LV systolic function versus the conventional method (Emax = 4.0 +/- 1.8 versus 3.3 +/- 1.2 mm Hg/mL [mean +/- standard deviation]; p = 0.08 by repeated-measures analysis of variance; physiologic intercept Ees100 = 20.3 +/- 8.6 mL [p < 0.05 versus control]), with no major change in LV diastolic stiffness. The posterior method had a lower Emax (3.3 +/- 1.2 mm Hg/mL) than the oblique method, but a similar Ees100 (20.8 +/-8.1 mL; p < 0.05 versus control) and the best diastolic LV performance (LV diastolic stiffness = 0.46 +/- 0.23 mm Hg/mL). The counter method also had good systolic function (Emax = 3.8 +/- 1.2 mm Hg/mL; Ees100 = 19.7 +/- 7.5 mL; p < 0.05 versus control), but had less favorable diastolic properties (0.65 +/- 0.37 mm Hg/mL; p < 0.05 by repeated-measures analysis of variance versus posterior).
  
  
  CONCLUSIONS
  In this isovolumic preparation in normal canine hearts, the oblique method of chordal resuspension was associated with the best LV systolic function, whereas the counter technique impaired LV diastolic function. These preliminary results warrant further study in ejecting and failing hearts to determine conclusively which chordal orientation best preserves LV performance after mitral valve replacement.
authors.affiliation: Department of Cardiovascular and Thoracic Surgery, Stanford University School of Medicine, California 94305-5247, USA.
authors.forename: M
authors.initials: M
authors.lastname: Komeda
authors.forename: A
authors.initials: A
authors.lastname: DeAnda
authors.forename: J R
authors.initials: JR
authors.lastname: Glasson
authors.forename: A F
authors.initials: AF
authors.lastname: Bolger
authors.forename: Y
authors.initials: Y
authors.lastname: Tomizawa
authors.forename: G T
authors.initials: GT
authors.lastname: Daughters
authors.forename: T L
authors.initials: TL
authors.lastname: Tye
authors.forename: N B
authors.initials: NB
authors.lastname: Ingels
authors.forename: D C
authors.initials: DC
authors.lastname: Miller
mesh_terms: D000818:Animals; D006348:Cardiac Surgical Procedures / Q000379:methods; D002815:Chordae Tendineae / Q000601:surgery*; D004285:Dogs; D006350:Heart Valve Prosthesis; D008943:Mitral Valve / Q000601:surgery*; D009200:Myocardial Contraction; D016277:Ventricular Function, Left