HES Patch Versus Blood Patch

The injection of autologous blood Blood Patch (BP) into the epidural space is the standard treatment for headache associated with intracranial hypotension. It provokes cerebral vasoconstriction. It is cons-indicated in a number of situations (HIV positive, fever, sepsis, leukemia). The purpose of this study is to evaluate another technique using a patch made by injecting an epidural hydroxyethylstarch solution (HES 130, 0.4, 6%) instead of blood patch. This alternative technique is simple to implement and does not have some of the specific blood pressure contra-indications. The study aims at comparing the "Blood Patch" group versus the "HES Patch" in terms of clinical efficacy , tolerance, satisfaction of the anesthetist, ease of implementation and effect of the injection of epidural anesthesia on cerebral blood flow within 24 hours.