Intrathecal Administration of Thrombin Inhibitor Ameliorates Cerebral Vasospasm

The role of thrombin as a spasmogen after subarachnoid hemorrhage was evaluated using the intrathecally administered thrombin inhibitor hirudin, released from a drug delivery system (DDS) based on collagen in a canine vasospasm model. The DDS was implanted into the cisterna magna with autologous blood in the hirudin-treated group. The reduction in the angiographical diameter of the basilar artery was only 19% in the hirudin-treated group on day 7, showing a significant difference between hirudin-treated and nontreated groups (p < 0.01). These results suggest that thrombin is an important cause of vasospasm. The collagen DDS has great potential for treatment in the cerebrospinal fluid milieu. Copyright (C) 2000 S. Karger AG, Basel.