Long-Term Results of Apical Aortic Conduits in Children With Complex Left Ventricular Outflow Tract Obstruction

Abstract

Apical aortic conduits were used in children with complex left ventricular outflow tract obstruction at our institution before we adopted the Ross and Ross-Konno procedures. The early results with apical aortic conduits were quite good when we used a porcine xenograft conduit and were less satisfactory when we converted to an aortic homograft valve as the conduit valve. This report summarizes our clinical experience with apical aortic conduits in children with an emphasis on hemodynamic results, reoperation, and long-term follow-up. Records of 28 patients (age range, 2 weeks to 19 years) who underwent insertion of apical aortic conduit between September 1979 and June 1993 were reviewed. All patients had complex multilevel left ventricular outflow tract obstruction. All were symptomatic, and 22 (79%) had had one or two previous aortic valvotomies or left ventricular outflow tract operations, or both. Hospital mortality was 11% (3 of 28). Twenty-five children survived the perioperative period and improved, and 21 have had one or more cardiac catheterization from 6 to 18 months (mean, 1.2 years) after the initial operation. Reduction or resolution of resting mean left ventricular-to-aortic peak gradient in the early postoperative period from 81.8 +/- 24.0 to 15.4 +/- 8.9 mm Hg was demonstrated (p < 0.001). Overall 25-year survival was 57%. Fourteen surviving patients (56%) have undergone subsequent procedures (n = 18) from 5 months to 16 years postoperatively (mean, 6.9 years) because they developed a recurrent left ventricular-to-aortic gradient of 58 +/- 28 mm Hg (p < 0.002). One patient underwent heart transplantation. All other late survivors have normal left ventricular function as determined by serial echocardiography. Apical aortic conduit is effective in relieving complex left ventricular outflow tract obstruction and improving left ventricular performance with acceptable short-term and midterm results, but late complications caused primarily by conduit tissue valve dysfunction are frequent in children. Since the early 1990s, the apical aortic conduit procedure has been largely replaced with the Ross or Ross-Konno procedure in our pediatric practice.