title: Toward the development of a fully elastic mitral ring: preliminary, acute, in vivo evaluation of physiomechanical behavior.
abstract: OBJECTIVE
  The optimal repair of functional mitral regurgitation is still debated. No device is able to simultaneously abolish mitral regurgitation and replicate natural mitral annular dynamics. We have tested a fully elastic mitral ring in an acute animal study with the purpose of evaluating (1) ring design and implantation technique, (2) elastic performance, and (3) acute effects on the native mitral annulus.
  
  
  METHODS
  Ten healthy sheep underwent surgical implantation of mitral devices, the elastic component of which is represented by a helicoid metallic spring. Preimplantation and postimplantation echocardiographic parameter measurements to evaluate annular dynamics and ventricular function comprise mitral annular motion, systolic tissue Doppler imaging peak wave, transmitral pressure gradient, peak transmitral flow velocity, and ejection fraction. Postimplantation angiographic analysis allowed measurement of the mitral annular area and perimeter variations by means of segmentation of the radiopaque mitral device contour.
  
  
  RESULTS
  No significant difference in terms of ejection fraction (P = .13) and systolic tissue Doppler imaging peak wave (P = .87) was found before and after implantation. Mitral annular motion (1.16 cm) was preserved. The percentage of systolic annular reduction derived from angiographic analysis was 14.1% (range, 7.7%-19.7%) in terms of area and 7.2% (range, 4.9%-10.0%) in terms of perimeter.
  
  
  CONCLUSIONS
  A mitral elastic ring, implantable by using a standard technique, acutely preserves mitral annular dynamics, allowing area and perimeter changes. Further chronic study is needed to verify the biocompatibility and durability of the device.
authors.affiliation: Dipartimento Cardiovascolare Clinico e di Ricerca, Ospedali Riuniti, Bergamo, Italy. pferrazzi@ospedaliriuniti.bergamo.it
authors.forename: Paolo
authors.initials: P
authors.lastname: Ferrazzi
authors.forename: Attilio
authors.initials: A
authors.lastname: Iacovoni
authors.forename: Samuele
authors.initials: S
authors.lastname: Pentiricci
authors.forename: Michele
authors.initials: M
authors.lastname: Senni
authors.forename: Maria
authors.initials: M
authors.lastname: Iascone
authors.forename: Nicolas
authors.initials: N
authors.lastname: Borenstein
authors.forename: Luc
authors.initials: L
authors.lastname: Behr
authors.forename: Alessandro
authors.initials: A
authors.lastname: Borghi
authors.forename: Rossella
authors.initials: R
authors.lastname: Balossino
authors.forename: Eugenio
authors.initials: E
authors.lastname: Quaini
mesh_terms: D000792:Angiography; D000818:Animals; D001696:Biomechanical Phenomena; D004548:Elasticity; D006350:Heart Valve Prosthesis; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000601:surgery* / Q000648:ultrastructure; D011474:Prosthesis Design; D012756:Sheep