PERCUTANEOUS NEEDLE TREPHINATION - EXPERIENCE IN 200 CASES

For many years percutaneous needle and classic burr-hole trephination with insertion of plastic catheters for external ventricular drainage are in use. The shortcomings of the conventional puncture needles were compensated for by the development of a modified instrument in recent years. In this prospective study we tried to define advantages and di sadvantages of percutaneous ventriculostomy with this modified needle in a large number of patients. We treated and followed a total number of 200 patients with external ventricular drainage for various reasons (42% obstructive hydrocephalus. 27% haematocephalus, 11% malresorptiv e hydrocephalus, 11% elevated ICP and 9% infections). The ventriculost omy is performed - after percutaneous trephination with a 1.5 mm drill and 1.2 mm needle under local anaesthesia as a bedside procedure. The modified blunt needle is provided with markings and a set screw which allows insertion to a prefixed depth and a sharp guide which is withd rawn after penetration of the dura. It is then bent rostrally and fixe d by a plaster cast. The mean duration of drainage was 9 days (1-30 da ys). Mean operating time for the whole procedure including fixation an d connection to the drainage system was 20 minutes. Overall complicati on rate was 13 % (N = 26). Two intracerebral haemorrhages (1%) occurre d, of which one was caused by overdrainage. Five (3%) infections in pr imarily not infectious cases (N = 182) were seen. Only one case of inf ection occurred without loosening of the needle on day 17. In 19 patie nts (10%) the needles had loosened. Fifteen times this complication wa s repaired in time and no infection occurred. The overall complication rate (13%) and the needle related risk of bleeding (0.5%) seem averag e. The true risk of infection with correct handling (0.5%) is very low despite the very long average duration of drainage. The main risk lie s in the markedly high danger of loosening (10%), which entails a disp roportionally high demand for nursing care. Nevertheless, we regard pe rcutaneous needle trephination as the ventriculostomy method of choice because of its better practicability and low infection rate.