Right ventricular outflow tract reconstruction using a Gore-Tex membrane monocusp valve in infant goats

Purpose: Biological materials including homografts are used for right ventricular outflow tract (RVOT) reconstruction in infants, but frequently require late replacement because of intrinsic deterioration. We examined the feasibility of using a polytetrafluoroethylene (Gore-Tex) valve in a chronic animal model. Methods: Eleven infant goats weighing 6.4 to 15.9 kg underwent RVOT reconstruction. The monocusp valve was constructed of Gore-Tex surgical membrane and the RVOT was roofed over utilizing a transannular patch (TAP) of bovine pericardium. The goats did not receive post-operative anti-coagulant therapy. The movement of the Gore-Tex valve was examined monthly by microscopy. Results: There were two deaths at 3 weeks and 4 months postoperatively by acute RVOT obstruction caused from thrombus formation between the valve and the TAP. Three goats with a functioning valve were sacrificed for histological analyses at 6 months postop. In contrast to the bovine pericardium which showed a prominent fibroinflammatory reaction with calcified areas, there was no apparent calcification or inflammatory reaction directed against the Gore-Tex valve. However, its base portion was encased by fibrous tissue extending from the TAP. There was no evidence of endothelization on the valve. The other six goats have a well-functioning valve up to ten months of follow-up. Conclusion: We conclude that Gore-Tex surgical membrane is an excellent material from which to create a monocusp valve during RVOT reconstruction. The TAP material is of concern because of the dense healing characteristics and thrombogenicity of bovine pericardium used in this study. Autologous pericardium or Gore-Tex might be better choices of material for a TAP. Clinical Implications: As a biologic valve substitute, Gortex may be a superior choice to create a monocusp valve for transannular outflow tract repair of Tetralogy of Fallot.

Duke Scholars

Author He Xu Surgery, Surgical Sciences