抄録
Sequential changes of subarachnoid space after subarachnoid hemorrhage were studied in animal experiments by scanning electron microscopical observations.
As a control study, the subarachnoid space of 14 dogs were observed with the scanning electron microscope. Then, 36 adult mongrel dogs underwent each direct injection of 1 ml/kg of fresh autogenous blood into the cisterna magna. Each of them was sacrificed at various periods ranging from immediately after to 6 months after the blood injection.
Six dogs, sacrificed immediately after the blood injection, showed subarachnoid hematoma at the base of the brain without expansion to the parietal region. In these hematomas, fibrin fibers were already observed among the red blood cells.
In all of 8 dogs sacrificed after 2-5 days of blood injection, subarachnoid clot was seen but no fibrosis had appeared. In 5 dogs after 7-9 days of blood injection, subarachnoid fibrosis in 4 and remaining clot in 2 were seen at this period. All of the 4 dogs killed after 2-3 weeks of the blood injection showed marked fibrosis or arachnoid thickening without remaining clot, and 3 of dogs sacrificed one month of the blood injection also showed subarachnoid fibrosis but normal findings were noted in the remaining 3. Moreover, even in 2 dogs which were sacrificed after 2 and 4 months respectively, marked fibrosis were observed.
Those results suggested that the blood in the basal subarachnoid space disappears within 1-2 weeks and fibrosis occurs 1-3 weeks after the subarachnoid hemorrhage. And, in most cases, subarachnoid fibrosis which occurs in early period disappears by a month or so after the hemorrhage. In some cases, however, fibrosis or arachnoid thickening lasts for several months or more.
The usefulness of scanning electron microscope to observe the subarachnoid space is emphasized.
