title: Stentless xenografts as an alternative to pulmonary homografts in the Ross operation.
abstract: OBJECTIVE
  Because of the limited availability of pulmonary homografts (PH), porcine stentless xenografts (SX) have been proposed as an alternative for pulmonary valve replacement in the Ross operation. However, it is unknown whether they have similar good long-term durability. Therefore, we compared mid- to long-term outcomes between those two right ventricular outflow tract (RVOT) substitutes.
  
  
  METHODS
  In 288 adults (>18 years) undergoing a Ross operation between 1991 and 2012, Freestyle(®) SX was used in 18 patients and a cryopreserved PH was used in 270 for RVOT reconstruction. Only patients with follow-up >2 years were included. According to the operative period, gender and age, 37 patients with PH could be matched with 17 SX patients. Clinical and echocardiographic follow-up were obtained. In a subset of patients (SX, n = 11 and PH, n = 25), a cardiac computed tomographic (CT) scan was performed to analyse graft calcification.
  
  
  RESULTS
  The mean follow-up period was 8.2 ± 4.0 (range 2-14.6 years). During this period, 3 patients died from cancer, 2 in the SX group and 1 in the PH group (P = 0.15). No patient needed RVOT reoperation. At follow-up, RVOT peak gradient was 21 ± 5.9 mmHg in the SX and 16.3 ± 8.7 in the PH groups (P = 0.07). Peak gradient >40 mmHg was observed in only 1 patient in the PH group. Mean RVOT regurgitation was 0.1 ± 0.4 in the SX group and 0.8 ± 0.6 in the PH group (P = 0.008). CT scan analyses showed progressive calcification mainly of the graft wall, while the valve remained relatively free of calcium. Patients with the SX presented significantly higher calcium scores than those with PH (P = 0.01).
  
  
  CONCLUSIONS
  In adult patients having the Ross operation, calcic degeneration is observed in both the PH and the SX used as pulmonary substitutes. Calcification progresses more rapidly in the SX compared with the PH. In both grafts, calcifications affect mainly the wall, while the valve remains relatively free of calcium. As a consequence, both grafts show good and similar haemodynamic outcomes at mid- to long-term follow-up. The Freestyle(®) SX can be considered as an acceptable alternative for RVOT reconstruction when PH is not available.
authors.affiliation: Department of Cardiothoracic and Vascular Surgery, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, Brussels, Belgium.
authors.forename: Jawad
authors.initials: J
authors.lastname: Hechadi
authors.forename: Bernhard L
authors.initials: BL
authors.lastname: Gerber
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Coche
authors.forename: Julie
authors.initials: J
authors.lastname: Melchior
authors.forename: Ramadan
authors.initials: R
authors.lastname: Jashari
authors.forename: David
authors.initials: D
authors.lastname: Glineur
authors.forename: Philippe
authors.initials: P
authors.lastname: Noirhomme
authors.forename: Jean
authors.initials: J
authors.lastname: Rubay
authors.forename: Gebrine
authors.initials: G
authors.lastname: El Khoury
authors.forename: Laurent
authors.initials: L
authors.lastname: De Kerchove
mesh_terms: D000328:Adult; D000818:Animals; D001021:Aortic Valve / Q000601:surgery; D000082882:Bicuspid Aortic Valve Disease; D015331:Cohort Studies; D005260:Female; D056973:Four-Dimensional Computed Tomography; D006330:Heart Defects, Congenital / Q000453:epidemiology / Q000601:surgery; D006349:Heart Valve Diseases / Q000453:epidemiology / Q000601:surgery; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000295:instrumentation / Q000379:methods; D006352:Heart Ventricles; D064593:Heterografts / Q000637:transplantation*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology; D011664:Pulmonary Valve / Q000637:transplantation*; D015607:Stents; D013552:Swine; D016896:Treatment Outcome
keywords: Pulmonary homograft; Pulmonary valve; Ross procedure; Stentless bioprosthesis