[Endothelial vasoactive factors: predictive markers of the results of the Fontan intervention?]

We retrospectively analyzed the pulmonary biopsies of a Fontan intervention in order to identify predictive markers of its result. The pulmonary biopsies of 17 patients who benefited from the Fontan intervention and 6 controls were studied. The histomorphometric measurements and endothelial expression of vasoactive factors (NO synthase, endothelin-1) and angiogenic factors (VEGF) were analyzed with immunohistochemistry at the level of intra-acini pulmonary arterioles. Eight patients presented a good surgical result (group 1). Distal arterioles presented a thin and regular wall: the NO synthase, endothelin and VEGF expression was low. Nine patients presented a failure of the Fontan operation (group 2). The distal arterioles were slightly musculated (p<0.01 vs. group 1 and group control). The endothelin-1 expression was comparable to that observed in group 1. Conversely, the NO synthase and VEGF expressions were significantly increased in that group (<0.001 vs. group 1 and group control).

In case of Fontan operation failure, the histological modifications are subtle with a muscular extension of the distal pulmonary arterioles wall. Conversely, a marked increase of NO synthase and VEGF expression is observed which can witness of an endothelial dysfunction. This study could be able to define predictive factors of the evolution and refine the selection of patients candidate for a Fontan operation.