title: Medtronic Freestyle valve for right ventricular reconstruction in pediatric Ross operations.
abstract: BACKGROUND
  The use of homograft conduits to reconstruct right ventricle (RV) to pulmonary artery (PA) connections is an essential component of the Ross operation. Homograft availability and cost may be problematic when considering the Ross operation. We elected in January 1998 to utilize commercially available xenografts as an alternative to homografts for RV/PA reconstruction in the pediatric Ross operation. Our early results using the Medtronic Freestyle valve (Medtronic, Minneapolis, MN) for RV/PA reconstruction are presented.
  
  
  METHODS
  We reviewed our database for all Ross operations performed on children since January 1998. A total of 16 patients were identified. Eleven children received a Medtronic Freestyle valve, 2 children received a homograft, and 3 children received another type of xenograft. Echocardiographic evaluation of all children who received the Medtronic Freestyle valve was performed at hospital discharge and at two subsequent outpatient evaluations.
  
  
  RESULTS
  The median peak instantaneous pressure gradient across the xenograft was 16 +/- 9 mm Hg (immediately after surgery before hospital discharge); 22 +/- 20 mm Hg at 23 +/- 11 months (first postdischarge follow-up); and 27 +/- 20 mm Hg at 35 +/- 9 months (second postdischarge follow-up). Linear regression analysis revealed an increasing pressure gradient with time (R(2)-adjusted = 0.44, p < 0.0001). At the same three observation points, the xenograft annulus diameter decreased: 25 +/- 1.2 mm; 19 +/- 4.3 mm; and 20 +/- 1.8 mm. Linear regression analysis revealed a decreasing annulus diameter with time (R(2)-adjusted = 0.41, p < 0.0001).
  
  
  CONCLUSIONS
  The Medtronic Freestyle valve provides a possible alternative to homografts for the reconstruction of the RV/PA connection in the pediatric Ross operation. Long-term follow-up is necessary to evaluate this xenograft as an alternative to the homograft.
authors.affiliation: Department of Surgery and Pediatrics, University of Tennessee, Memphis, 38104, USA. ichfno@aol.com
authors.forename: William M
authors.initials: WM
authors.lastname: Novick
authors.forename: Darko
authors.initials: D
authors.lastname: Anic
authors.forename: Alfredo
authors.initials: A
authors.lastname: Lora Solf
authors.forename: Miguel
authors.initials: M
authors.lastname: Arboleda Torres
authors.forename: Ivan
authors.initials: I
authors.lastname: Niño De Guzmán León
authors.forename: Robert W
authors.initials: RW
authors.lastname: Reid
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Di Sessa
mesh_terms: D000293:Adolescent; D019917:Blood Vessel Prosthesis Implantation / Q000379:methods*; D002648:Child; D002675:Child, Preschool; D015150:Echocardiography, Doppler; D019918:Heart Valve Prosthesis Implantation; D006352:Heart Ventricles / Q000601:surgery; D006801:Humans; D011664:Pulmonary Valve / Q000601:surgery; D014183:Transplantation, Heterologous