title: Premature failure of small-sized Shelhigh No-React porcine pulmonic valve conduit model NR-4000.
abstract: OBJECTIVE
  Given the limited availability of small-sized cryopreserved pulmonary homografts, we implanted a series of Shelhigh No-React porcine pulmonic valve conduits (SPVC). The aim of this study was to evaluate the short-term performance following implantation.
  
  
  METHODS
  From February 2000 to September 2000, the SPVC was implanted 25 times in 24 patients in the right ventricular outflow tract (RVOT) to correct congenital anomalies. The anatomical malformations were TOF/PA in eight patients, TGA/VSD/PS in four, truncus arteriosus in four, IAA/VSD/AS or AA in four, l-TGA/VSD in two and other in two. Age at operation was 2.8+/-3.9 years (mean+/-SD), including 12 patients under 1 year. The median conduit size was 14mm (range, 10-18).
  
  
  RESULTS
  At a mean follow-up of 23+/-5 months, two late deaths (8%) have occurred. Although they were not primarily conduit related, both showed severe conduit stenosis. Twenty-one conduits (84%) showed mild to severe conduit stenosis, regurgitation or both. Two patients underwent balloon dilatation for distal conduit stenosis. Twelve conduits (48%) in 11 patients were removed at a median of 12 months (range, 2-18 months) due to RVOT obstruction in 11 and free conduit insufficiency with pseudoaneurysm in one. The typical findings of the explanted conduits were prominent intimal peel formation at the distal anastomosis without calcification. The actuarial freedom from reintervention at 18 months was 48+/-10%.
  
  
  CONCLUSIONS
  Our experience of the SPVC with the diameter of 14mm or less has revealed a high incidence of distal conduit stenosis due to intimal peel formation resulting in early conduit failure. These findings have led us to abandon its use when other options are available.
authors.affiliation: Section of Cardiac Surgery, Division of Pediatric Cardiovascular Surgery, F7830 C.S. Mott Children's Hospital, 1500 East Medical Center Drive, The University of Michigan Health System, Ann Arbor, MI 48109, USA.
authors.forename: Toru
authors.initials: T
authors.lastname: Ishizaka
authors.forename: Richard G
authors.initials: RG
authors.lastname: Ohye
authors.forename: Caren S
authors.initials: CS
authors.lastname: Goldberg
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Ramsburg
authors.forename: Takaaki
authors.initials: T
authors.lastname: Suzuki
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Devaney
authors.forename: Edward L
authors.initials: EL
authors.lastname: Bove
mesh_terms: D001705:Bioprosthesis / Q000592:standards*; D002675:Child, Preschool; D005500:Follow-Up Studies; D006083:Graft Occlusion, Vascular / Q000209:etiology; D006330:Heart Defects, Congenital / Q000150:complications / Q000601:surgery*; D006350:Heart Valve Prosthesis / Q000592:standards*; D006801:Humans; D011379:Prognosis; D011475:Prosthesis Failure; D011664:Pulmonary Valve / Q000002:abnormalities*; D012008:Recurrence; D012189:Retrospective Studies; D014183:Transplantation, Heterologous; D014694:Ventricular Outflow Obstruction / Q000209:etiology / Q000601:surgery*