invasive treatment of a vessel, optionally having secondary vessels, with a tip (10) at the distal end of a rod (2) which must be introduced into the body and with at least one functional unit Instrument (4, 5, 6, 7, 8, 9, 20, 22), characterized in that the tip (10) is constructed for tissue dissection and has at least one housing means cup (17) which is arranged and performed so that in the operating state of the instrument (1), is free always at least one functional unit (4, 5, 6, 7, 8, 9, 20, 22) of the shaft (2), so that it is possible to work in the vessel (14), a secondary vessel (40) and / or surrounding tissue or by the functional unit (4, 5, 6, 7, 8, 9, 20, 22 ) and with at least one housing means cup (17), the vessel (14) can be fixed in a position in space, being movable tip (10) by a guide element (9) relative the stem (2) and pudiend or slide the tip (10) axially, so that, during engagement, a glass (14) disposed in at least one housing means cup (17) can be maintained selectively at a distance of functional unit (4, 5, 6, 7, 8, 9, 20, 22), and a tip of the endoscope (19) projects from the distal end of the rod (2) into the retracted tip (10), and the tip (10) is transparent.Instrumento invasivo para el tratamiento de un vaso que, dado el caso, presenta vasos secundarios, con una punta (10) en el extremo distal de un vástago (2), que ha de ser introducido en el cuerpo y con al menos una unidad funcional (4, 5, 6, 7, 8, 9, 20, 22), caracterizado por que la punta (10) está realizada para la disección de tejido y presenta al menos un medio de alojamiento de vaso (17), que está dispuesto y realizado de tal forma que, en el estado de funcionamiento del instrumento (1), queda libre siempre la al menos una unidad funcional (4, 5, 6, 7, 8, 9, 20, 22) del vástago (2), de manera que es posible realizar trabajos en el vaso (14), en un vaso secundario (40) y/o en el tejido circundante con o por la unidad funcional (4, 5, 6, 7, 8, 9, 20, 22) y que con el al menos un
