fig3 video probe 20 is pivoted at guide shaft 60 in a resting position which allows to introduce guide shaft 60 together with video probe 20 through trocar 16 into abdomen 12 of the patient to be treated as can be seen in front view according to fig4 video probe 20 is located in such a position that its outer cross sectional contour 72 is arranged essentially within and thus congruent to the outer cross sectional contour of guide shaft 60 the working position of video probe 20 of guide shaft 60 corresponds to the representation of guide shaft 14 in fig1 in the representation in fig4 furthermore a guide channel 76 of guide shaft 60 can be seen which is open on both ends i e at its distal end 38 and at its proximal end 68 in that way it is possible to introduce different working instruments 24 into guide shaft 60 or to remove them from the same in the course of the operation with reference numerals 77 and 78 two illumination devices are designated which are arranged at the distal end of guide shaft 60 and at image pick up unit 20 illumination device 77 comprises two led 39 s which are integrated in guide shaft 60 at both sides of guide channel 76 illumination device 78 comprises in comparison a disordered fiber bundle wherein the fiber ends are arranged concentrically to an image entrance opening 79 instead of the fiber bundles however also led 39 s can be.