70 M. DE MONTI et al. FIGURE 2 First trans-nasobiliary tube cholangiography (5th post-ERCP day): the biliary fistula of the VIIIth segment is still evident. CONCLUSIONS Operative endoscopy and nasobiliary drainage pro- vide excellent results and is supported by a breadth of international literature, which suggests that endo- scopic operative techniques must be the treatment of choice for postoperative and traumatic external biliary fistulas. Moreover, endoprostheses can be used when nasobiliary tube aspiration is not functioning, espe- cially in fistulas caused by neoplastic involvement of the biliary tract. References Magistrelli, P., Masetti, R., Coppola, R., et al. (1989). Value of ERCP in the diagnosis and management of pre and postopera- tive biliary complications in hydatid disease of the liver, Gastrointest RadioL 14, 315-320. [2] Iscan, M., Duren, M. (1991). Endoscopic sphincterotomy in