To Study The Effect Of Long Time Continuing Drainage Of Cerebrospinal Fluid For Arachnoid Granulations

Objective:Arachnoid granulations(AG)that long time continuing drainage of cerebrospinal fluid is changed or not,the rule of arachnoid granulations changed by the time.The affect that arachnoid granulations of continuing drainage of cerebrospinal fluid will contribute to conduct clinical apply.Methods:A random sample of 26 healthy mongrel dogs was selected.2 dogs were as the comparison group,24 dogs with drainage of cerebrospinal fluid was selected as the experimental group,24 dogs were randomly divided into 4 group(A B C D),comparison group were left intact,experimental group measure intracranial pressure with external lumbar drainage at the same time.MRI measurements of cerebral ventricle after clamping of the drainage tube of A group.Keeping drainage unobstructed 14 days of B group.Measurement of intracranial pressure and MRI measurements of cerebral ventricle when we clamping the drainage after 24 hours.Then the animals were killed,tissue were fixed with 4% paraformaldehyde by heart.Serial section was performed in sagittal sinus and transverse sinus of three dogs of B group,0.5um of section thickness,hematoxylin eosin(HE)stain,the tissue structure was observedunder the light microscope.Arachnoid granulations of other dogs of B group was observed under transmission electron microscope.We observe interior structures and surface structures of arachnoid granulations.C group continuing drainage of cerebrospinal fluid 21 days.D group continuing drainage of cerebrospinal fluid 28 days.Subsequent work on the same B group.We observe interior structures and surface structures of arachnoid granulations of the comparison group by light microscope and electron microscope.Results: 1.Themodel of continuing drainage of cerebrospinal fluid from lumbar pool,measurement of intracranial pressure at different periods,B group measure intracranial pressure 2 weeks after continuing drainage of cerebrospinal fluid,C group measure intracranial pressure 3 weeks after continuing drainage of cerebrospinal fluid,D groupmeasure intracranial pressure 4 weeks after continuing drainage of cerebrospinal fluid,the results show that A group pressure above other three groups.Clamping of the drainage tube 1 day of B group,C group and D group,respectively.The results show that C group and D group pressure above A group.2.We used magnetic resonance imaging to see how drainage affects the ventricle when we clamping of the drainage tube 1 day of B group,C group and D group.Ventricle indices were compared in different groups.The result had no significant difference between four groups(P>0.05),there were no obvious abnormal changes in the check of brain.3.The size and state of arachnoid granulations that was observed under the light is not the same.There are rich endothelial cells and fibrous capsule,it?s made up of a complex network.Compared with endothelial cells of continuous lumbar cistern drainage group,control group were taken with electron microscope.Vesicles generally existed in endothelial cells,fingerlike projection or lobe on the body of endothelial cells.Arachnoid cells and fibers of the protein collagen are intertwined in core of arachnoid granulations,there are many pleomorphic astrocytes inhypercellular areas.Conclusions: 1.The arachnoid granulations are placed at low pressure 4 weeks with no sign of atrophy.Transport function of endothelial cells of arachnoid granulations was not injured.Continuing drainage of cerebrospinal fluid cannot lead to hydrocephalus 4 weeks.Continuing drainage of cerebrospinal fluid will be safe in 4 weeks.2.Intracranial pressures have elevated when we clamping the drainage tube of A group with continuing drainage 3weeks.Arachnoid granulations remains unchanged and have absorptive function.Intracranial hypotension might cause another way of absorbing cerebrospinal fluid except arachnoid granulations.3.The shapes of arachnoid granulations of dog were differ,fingerlike projection or lobe on the body of endothelial cells.Vesicles generally existed in endothelial cells.There are rich endothelial cells and fibrous capsule,it?s made up of a complex network.rachnoid cells and fibers of the protein collagen are intertwined in core of arachnoid granulations,there are many pleomorphic astrocytes inhypercellular areas.