title: Quantitative assessment of homograft function 1 year after insertion into the pulmonary position: impact of in situ homograft geometry on valve competence.
abstract: OBJECTIVE
  To prospectively evaluate homograft function with cardiac magnetic resonance (CMR) imaging 1 year after insertion into the pulmonary position, and to assess the impact of in situ homograft geometry, surgical factors, and 'intrinsic' homograft properties on early valve incompetence.
  
  
  RESULTS
  A total of 60 patients (mean age 21 +/- 10 years; 35 females) with congenital heart disease underwent pulmonary valve replacement with homograft insertion and were prospectively enrolled into a study protocol that included serial echocardiography and CMR 1 year after surgery. None of the patients had homograft stenosis but 10 (17%) had significant homograft incompetence (i.e. pulmonary regurgitation fraction >20% on CMR). A higher incidence of 'eccentric' pulmonary forward flow pattern (P < 0.001, Fisher's exact test), more acute 'homograft distortion angle' (P < 0.001), larger relative 'annular' size (P < 0.01), and greater pre-homograft right ventricular outflow tract (RVOT) diameters (P = 0.01) at CMR was seen in those with worse homograft function. In a backward multivariate linear regression model, 'eccentric' pulmonary forward flow pattern (r(part) = 0.36, P < 0.001), 'homograft distortion angle' (r(part) = 0.31, P = 0.001), and pre-homograft RVOT diameter (r(part) = 0.19, P = 0.03) were independently associated with the degree of pulmonary regurgitation (in %) at 1 year.
  
  
  CONCLUSIONS
  Using CMR, in this prospective cohort study, we have shown that significant valve incompetence is present in one-sixth of patients after homograft insertion into the pulmonary position, and that alterations in the in situ homograft geometry were associated with the likelihood of developing valve incompetence. These findings imply that mechanical factors may have an important impact on homograft performance.
authors.affiliation: Cardiovascular Unit, UCL Institute of Child Health and Great Ormond Street Hospital for Children NHS Trust, London WC1N 3JH, UK.
authors.forename: Johannes
authors.initials: J
authors.lastname: Nordmeyer
authors.forename: Victor
authors.initials: V
authors.lastname: Tsang
authors.forename: Régis
authors.initials: R
authors.lastname: Gaudin
authors.forename: Philipp
authors.initials: P
authors.lastname: Lurz
authors.forename: Alessandra
authors.initials: A
authors.lastname: Frigiola
authors.forename: Alexander
authors.initials: A
authors.lastname: Jones
authors.forename: Silvia
authors.initials: S
authors.lastname: Schievano
authors.forename: Carin
authors.initials: C
authors.lastname: van Doorn
authors.forename: Philipp
authors.initials: P
authors.lastname: Bonhoeffer
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Taylor
mesh_terms: D000328:Adult; D004452:Echocardiography; D005260:Female; D006085:Graft Survival; D006330:Heart Defects, Congenital / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000379:methods*; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D011446:Prospective Studies; D011664:Pulmonary Valve / Q000601:surgery*; D011665:Pulmonary Valve Insufficiency / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D013318:Stroke Volume / Q000502:physiology; D014184:Transplantation, Homologous; D016896:Treatment Outcome; D055815:Young Adult