Effect and mechanism of lumbar subarachnoid space continuous drainage on cerebral vasospasm prevention and treatment following experimental subarachnoid hemorrhage

Objective To investigate the effect of lumbar subarachnoid space continuous drainage on cerebral vasospasm(CVS) prevention and treatment following experimental subarachnoid hemorrhage(SAH), and further explore the mechanism of CVS prevention and treatment.Methods An experimental SAH was achieved by twice injections of fresh autologous arterial blood into cisterna magna of each dog. The dogs were randomly divided into drainage group and control group and it was just after the second injection of fresh blood that the drainage group began to drain blood cerebral spinal fluid(CSF).The contents of red blood cell(RBC), endothelin-1(ET-1) and nitric oxygen(NO) in CSF were measured respectively. The degree of CVS was analyzed through angiography (%reduction of basilar artery diamiter,%RBAD). The angiographic results of CVS were analyzed and the changes of RBC, ET-1 and NO in CSF at different stages were compared between two groups. Results The drainage group had fewer cases of CVS and the severity of CVS was more slight compared with control group.Drainage group had a significantly higher cleaning rate of RBC.In drainage group,the content of ET-1 was lower and the content of NO was higher significantly than control group.Conclusions Through cleaning the vasogenic substances in subarachnoid space,lumbar subarachnoid space continuous drainage can change the levels of ET-1 and NO in CSF and may prevent and reverse CVS following.