The freestyle valve as a right ventricle to pulmonary artery conduit. A systematic review and meta-analysis

INTRODUCTION: Reconstruction of the right ventricular outflow tract is the most commonly performed valve repair/replacement procedure in congenital cardiac surgery. There is an ongoing shortage of homografts, and existing bioprosthetic options suffer from substantial rates of structural valve deterioration over time. The Medtronic Freestyle valve is used extensively in the aortic position, but little data is available on its performance in the pulmonary position. METHODS: A systematic review and meta-analysis of primary studies reporting echocardiographic and clinical outcomes, including reintervention and functional status, associated with the Freestyle valve in the pulmonary position for both Ross and congenital surgery. RESULTS: 13 observational studies including 334 patients with a mean follow-up of 34 months (range 10-98 months) fulfilled the eligibility criteria and were included in the review. Structural valve deterioration occurred in 4.8% (95% confidence interval 0.8-10.6%) of patients. Reintervention was required in 1.1% (95% confidence interval 0.0-3.3%). Freedom from symptoms of heart failure occurred in 97.7% (94.6-99.7%). The results did not change substantially when analysed according to Ross or congenital surgery. CONCLUSIONS: The Freestyle valve performs well at short-term follow-up and provides a viable alternative when homografts are unavailable. Further long-term studies are required to better assess its role in right ventricular outflow tract reconstruction.