Repeat right ventricular outflow tract reconstruction using the Medtronic Freestyle porcine aortic root

Abstract

Background and aim of the study: A variety of valve substitutes are used for right ventricular outflow tract (RVOT) reconstruction in children and young adults after previous RVOT surgery that has led to significant pulmonary insufficiency and/or stenosis. Herein, the authors' experience with pulmonary valve replacement (PVR) using a porcine valved conduit late after previous RVOT surgery was reviewed.

Methods: Between August 2002 and April 2005, 31 patients (mean age 14.5 +/- 9.5 years; range: 1.2-33.1 years) underwent PVR using the Medtronic Freestyle porcine aortic root. These patients averaged two prior operations (range: 1-5) for the following diagnoses: tetralogy of Fallot +/- pulmonary atresia (n = 21); persistent truncus arteriosus (n = 5); aortic stenosis (Ross-Konno procedure) (n = 2); pulmonary atresia with intact ventricular septum; (n = 1); congenital pulmonary stenosis (n = 1); and transposition of the great arteries (n = 1). Of these patients, 29 (93.5%) underwent additional procedures at the time of pulmonary valve insertion including: branch pulmonary artery reconstruction (n = 21), atrial septal defect closure (n = 5), ascending aorta replacement (n = 4), pacemaker or defibrillator placement (n = 3), tricuspid valve repair (n = 2), ventricular septal defect closure (n = 2), and other procedures (n = 2).

Results: There were no early or late deaths. The mean hospital stay was 8.3 +/- 5.9 days (range: 4-25 days). One patient had a subarachnoid hemorrhage with transient left hemiparesis, and two patients had acute tubular necrosis with temporary dialysis treatment. All patients were well at a mean follow up of 13 +/- 9.3 months (range: 0.5-31 months). Echocardiography showed trivial or no pulmonary insufficiency in 30 patients (96.7%). The calculated mean peak systolic RVOT gradient by echocardiography was 23.4 +/- 7.6 mmHg.

Conclusion: The Medtronic Freestyle bioprostheses demonstrated excellent short-term results for repeat RVOT reconstruction. This valve's hemodynamic characteristics are comparable to those of homografts, and it is an attractive alternative given the limited availability of homograft valves. A lack of availability in sizes smaller than 19 mm limits use of this valve in pediatric patients, and long-term results remain to be determined.