Author/Authors :
Michael D. Black، نويسنده , , S. Jill Ley، نويسنده , , Anne-Marie Regal، نويسنده , , Richard E. Shaw، نويسنده ,
Abstract :
Background
The use of a stentless aortic bioprosthesis offers the advantages of a larger effective valve orifice size, reduced transvalvular gradients, and improved hemodynamics versus stented valves. We hypothesized that these features would make the Toronto stentless porcine valve a preferred choice for patients with congenital abnormalities of the right ventricular outflow tract.
Methods
We retrospectively reviewed medical records of 21 patients with tetralogy of Fallot who subsequently underwent right ventricular outflow tract reconstruction during a 6-year period.
Results
The majority of patients received a 29-mm valve (n = 13), 5 received a 27-mm valve, with 1 each additional implant of a 19-, 22-, and 23-mm prosthesis. The mean age and weight were 24.5 years (range, 7 to 54 years) and 55.6 kg (range, 13.9 to 98.0 kg), respectively. Preoperatively, all patients had severe pulmonary insufficiency, mixed with mild to moderate stenosis in 2. The duration of postoperative echocardiographic follow-up ranged from 10 to 70 months (mean, 37.7 months). At the time of most recent follow-up, pulmonary insufficiency was graded as zero to trace in 47.4% (9 of 19 patients), mild in 42.1% (8 of 19 patients), and moderate in 10.5%, with 6 patients (31.6%) having concomitant pulmonary stenosis. The most recent mean and peak transvalvular gradients averaged 17.4 mm Hg (range, 11 to 24 mm Hg) and 26 mm Hg (range, 13 to 42 mm Hg), respectively. There have been no valve-related complications or explants, with one late death as a result of a noncardiac cause.
Conclusions
The stentless porcine valve is well suited for valve replacement in children, adolescents, and adults with congenital abnormalities of the right ventricular outflow tract, regardless of patient or valve size, particularly when significant downstream hemodynamic abnormalities exist.