[Decompressive trepanation in therapy refractory brain edema].

Already in 1905 and 1908 Harvey Cushing carried out decompression operations for the relieving of pressure in inoperable glious tumours and posttraumatic cerebral oedmas. This surgical method of trephination, which later-on was adopted by many other surgeons, was based on the method of the prevention of an incarceration of the mesencephalon in the tentorial slit by an enlargement of the reserve space in the interior of the crane. In case of a posttraumatic cerebral oedema, besides Heppner's work group practically all other authors operated in pronounced late stages of the incarceration. The results obtained were bad. Heppner worked on the basis of a wider indication, operated earlier, and obtained better results. The intervention should be performed on the basis of continuous preoperative measuring of the cerebral pressure. By means of calculations and modelling we were in a position to demonstrate that on both sides very large trephination areas with the relation of the radius of the trephination area to the radius of the head being 2 to 3 are necessary for achieving a sufficient decrease of the pressure by about 20 to 30 torr.