Relationship between cerebral vasospasm and drainage of cerebral spinal fluid following subarachnoid hemorrhage

Objective: To investigate the relationship between hematocele change of cerebral spinal fluid (CSF) and cerebral vasospasm(CVS) following experimental subarachnoid hemorrhage(SAH).Methods: An experimental SAH model was achieved in dogs by twice injecting fresh autologous arterial blood into the cisterna magna of each animal.The hematocele change in CSF were measured at different stages in early drainage group,later drainage group and control group respectively.The degrees of CVS were analyzed through cerebral angiography (proportion of reduction of basilar artery diamiter, %RBAD). Results:The early drainage group had a higher clearing rate of hematocele in CSF than other 2 groups following two injection model, the later drainage group had a higher clearing rate of hematocele than that of control group only after draining.Compared with other 2 groups,the early drainage group had less CVS and the degrees of CVS were slighter.Conclusion:Large volume of hematocele in CSF in experimental SAH leads to a high incidence of CVS and the degree of CVS become more severe as time goes on.Lumber subarachnoid space continuous drainage following SAH can prevent CVS.Early drainage may lead to a better outcome.