G Martin1, K Slim2. 1. Service de chirurgie digestive, CHU Estaing, place Lucie-Aubrac, 63003 Clermont-Ferrand, France. Electronic address: gmartin@chu-clermontferrand.fr. 2. Service de chirurgie digestive, CHU Estaing, place Lucie-Aubrac, 63003 Clermont-Ferrand, France.