“…23 A m uch sm aller variance was found in a review of m ore recent studies, however, where m ortality rates between 1.5 and 6.6% were reported. 14 The results of the present study con® rm the observation, which has already been m ade in earlier studies, 8,14,22,23,33 that this treatm ent m ethod results in a very low rate of com plications if the postoperative course is m onitored closely. For this reason, the prognosis for patients with chronic SD H , who are usually older, is determ ined m ainly by their condition at adm ission, 17,34 their general condition, and the accom panying diseases 6,14,34,35 which are frequently presented.…”