Abstract: An instrument comprising a tubular staple case is disclosed, the case being traversed by a supporting rod extending outwardly therefrom with its front end. The tubular case is used to mount a plunger with a knife arranged on the rod. An abutment head mounted on the front end of the rod is made generally longitudinally detachable consisting of two members, an internal member detachably mounted on the front end of the rod and an external member encompassing the internal member and made up of interdetachable rests. Moreover, provision is made for a staple magazine and a female die with grooves for bending staples as well as a drive imparting motion to the plunger and a mechanism for adjusting the gap between an end of the case and an end of the head.