The authors believe that utilisation of calibrating drainage is justified in case of difficult restauration of the C.B.D. of normal caliber, either throughout its length or in one segment. They underline that "axial exit" has not the disadvantages of the "lateral exit" of T-tubes. They recall the various modalities of "axial exit" (transcystic, transpapillary, transhepatic, "en seton") and their own contribution to the improvement of the transpapillary drainage by the association of a systematic sphincterotomy. Abstract of their clinical series, technics, postoperative mortality and morbidity, calibrating drainage duration and results (in connection with etiology) are reported. Main advantages of the "axial exit" are the absence of any risk of stenosis on a non dilated C.B.D. (as for the "lateral exit") and the facility for long time calibration up to several years. No hemorrhage, no bile leakage have been observed. The one only risk of this sort of drainage is the premature fall of transcystic or transpapillary drains ; but this disadvantage does not exist for "en seton" drainage. Shortly : "axial exit" calibrating drainage is recommandable when a very long time calibration after restauration of non dilated C.B.D. is necessary.