title: Pulmonary homograft muscle reduction to reduce the risk of homograft stenosis in the Ross procedure.
abstract: OBJECTIVE
  The Ross procedure has gained increasing interest as an attractive alternative for aortic valve replacement. Despite its advantages, there is a certain risk of structural valve deterioration, especially of the pulmonary homograft as a result of shrinkage and subsequent stenosis predominantly at the muscular annulus. Theoretically, reduction of homograft muscle tissue could reduce this risk.
  
  
  METHODS
  From February 1996 through December 2002, a total of 238 patients (mean age 44 +/- 13.2 years) underwent the Ross procedure with the subcoronary technique with follow-up investigations before discharge and after 12 and 24 months. To estimate the importance of homograft muscle reduction within our institution-specific risk factor scale for change of transhomograft pressure gradient with time, we performed a generalized estimating equation approach, which identified homograft muscle reduction, higher body surface area in male patients, younger patient age, smaller homograft diameter, blood transfusions, and follow-up time as independent risk factors demonstrating a high beta value (-2.8638) for muscle reduction. To find out whether muscle reduction influences transhomograft pressure gradient, we compared patients with (group A, n = 39) and without (group B, n = 199) muscle reduction. The other mentioned independent risk factors were not different between groups, except for blood transfusions (group A greater than B, P < .01), indicating a negative bias for group A.
  
  
  RESULTS
  The maximum pressure gradient across the homograft was lower in patients with muscle reduction before discharge (4.5 +/- 2.8 mm Hg group A vs 6.2 +/- 3.8 mm Hg group B, P = .004) and after 1 (9.3 +/- 5.8 vs 13.1 +/- 8.4 mm Hg, P = .028) and 2 years (10.8 +/- 7.6 vs 13.7 +/- 7.5 mm Hg, P = .013). No significant differences were found concerning homograft insufficiency.
  
  
  CONCLUSIONS
  We provide some evidence that transhomograft pressure gradient can be reduced significantly within the first 2 years after operation by homograft muscle reduction. Longer term follow-up is necessary to evaluate this promising operative technique further.
authors.affiliation: Klinik für Herzchirurgie, Lübeck, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Schmidtke
authors.forename: Gerlinde
authors.initials: G
authors.lastname: Dahmen
authors.forename: Bernhard
authors.initials: B
authors.lastname: Graf
authors.forename: Hans-H
authors.initials: HH
authors.lastname: Sievers
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001021:Aortic Valve / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D006348:Cardiac Surgical Procedures / Q000009:adverse effects; D003251:Constriction, Pathologic; D004452:Echocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009130:Muscle, Smooth / Q000601:surgery; D011183:Postoperative Complications; D011664:Pulmonary Valve / Q000473:pathology / Q000637:transplantation*; D012086:Reoperation; D012307:Risk Factors; D014184:Transplantation, Homologous