Impaired capillary perfusion and brain edema following experimental subarachnoid hemorrhage: a morphometric study

1990 ◽  
Vol 73 (3) ◽  
pp. 410-417 ◽  
Author(s):  
Hiroo Johshita ◽  
Neal F. Kassell ◽  
Tomio Sasaki ◽  
Hisayuki Ogawa

✓ To evaluate microcirculatory disturbance and cerebral edema associated with subarachnoid hemorrhage (SAH), both stereological morphometry on the intraparenchymal capillary network and microgravimetry were performed on a rabbit SAH model. Autologous arterial blood (5 ml) was injected into the cisterna magna, and the animals were sacrificed at intervals of 6 hours, 1 day, 2 days, or 6 days after SAH. Capillaries in the piriform cortex, parasagittal cortex, and ventral brain stem of the midline-hemisectioned brain were injected with Evans blue dye 1 minute before sacrifice, and were planimetrically evaluated under a fluorescence microscope connected to an image analysis system. Stereological and morphological parameters including the volume density, surface density, numerical density, minimum intercapillary distance, and the diameter of Evans blue-perfused capillaries were also computed. In the piriform cortex and ventral brain stem, the volume and surface densities were significantly reduced and the minimum intercapillary distance was significantly increased 1 to 2 days after SAH. In the parasagittal cortex far from the cisternal clot, changes in the parameters were minimal. Cerebral blood volume (CBV) in the normal condition and edema formation associated with SAH were studied by the microgravimetric technique. The mean CBV in the parasagittal cortex, piriform cortex, and brain stem was 6.9%, 6.8%, and 5.6%, respectively. Following SAH, specific gravity in the piriform cortex and the ventral brain stem of the other side of the hemisectioned brain was significantly decreased at 1 to 2 days, showing a change parallel to that of the stereological parameters. The results obtained from the morphometric technique indicated the occurrence of impaired capillary perfusion and reduced capillary blood volume following SAH, while microgravimetry suggested the formation of brain edema during this period. These changes in the intraparenchymal vessels may play an important role in the pathophysiology of SAH.

2000 ◽  
Vol 93 (2) ◽  
pp. 183-193 ◽  
Author(s):  
Anthony Marmarou ◽  
Panos P. Fatouros ◽  
Pal Barzó ◽  
Gennarina Portella ◽  
Masaaki Yoshihara ◽  
...  

Object. The pathogenesis of traumatic brain swelling remains unclear. The generally held view is that brain swelling is caused primarily by vascular engorgement and that edema plays a relatively minor role in the swelling process. The goal of this study was to examine the roles of cerebral blood volume (CBV) and edema in traumatic brain swelling.Methods. Both brain-tissue water and CBV were measured in 76 head-injured patients, and the relative contribution of edema and blood to total brain swelling was determined. Comparable measures of brain-tissue water were obtained in 30 healthy volunteers and CBV in seven volunteers. Brain edema was measured using magnetic resonance imaging, implementing a new technique for accurate measurement of total tissue water. Measurements of CBV in a subgroup of 31 head-injured patients were based on consecutive measures of cerebral blood flow (CBF) obtained using stable xenon and calculation of mean transit time by dynamic computerized tomography scanning after a rapid bolus injection of iodinated contrast material. The mean (± standard deviation) percentage of swelling due to water was 9.37 ± 8.7%, whereas that due to blood was −0.8 ± 1.32%.Conclusions. The results of this study showed that brain edema is the major fluid component contributing to traumatic brain swelling. Moreover, CBV is reduced in proportion to CBF reduction following severe brain injury.


1986 ◽  
Vol 64 (4) ◽  
pp. 643-649 ◽  
Author(s):  
Shizuo Hatashita ◽  
Julian T. Hoff ◽  
Shozo Ishii

✓ Acute arterial hypertension was studied in normal cats to determine its role in the formation of brain edema. Arterial hypertension was induced for 30 minutes by inflation of a balloon catheter situated in the descending aorta. Cerebral edema was evaluated by gross and microscopic observations, tissue water content by wet/dry weights, and blood-brain barrier (BBB) permeability by extravasation of horseradish peroxidase (HRP) and Evans blue dye. For 1 hour after the hypertensive insult, tissue pressure and regional cerebral blood flow (rCBF) were measured from the arterial boundary zone and from a non-boundary region, and intracranial pressure was recorded from the lateral ventricle as ventricular fluid pressure. Focal lesions with increased BBB permeability to Evans blue dye or HRP were usually located symmetrically in the cortex, corresponding to the occipitoparietal parts of the arterial boundary zones. The increase in water content was found only in areas of increased permeability. Tissue pressure increased simultaneously with the abrupt rise in blood pressure, and an increase in rCBF paralleled the elevation of blood pressure. Tissue pressure and rCBF returned to a steady state when blood pressure returned to normal. There were no differences in tissue pressure or rCBF between the arterial boundary zone and the non-boundary zone, even during arterial hypertension. In cerebral hemispheres examined 48 hours after the hypertensive challenge, brain edema had not continued to develop. The data indicate that acute arterial hypertension may produce focal brain edema with increased permeability of the BBB in the cortex of normal brain, particularly in the arterial boundary zones. The authors postulate that increased cerebral blood volume, high intraluminal pressure, and breakthrough of autoregulation play an important role in the formation of hypertensive brain edema.


2004 ◽  
Vol 101 (1) ◽  
pp. 99-103 ◽  
Author(s):  
Gustavo Pradilla ◽  
Paul P. Wang ◽  
Federico G. Legnani ◽  
James L. Frazier ◽  
Rafael J. Tamargo

Object. Implantation of controlled-release polymers into the subarachnoid space to deliver drugs for treatment of vasospasm after subarachnoid hemorrhage (SAH) is currently of interest. Among the issues regarding local delivery of drugs in the subarachnoid space, however, are the extent of diffusion and the rate of release of the loaded agents. In this study Evans blue dye (EBD) was loaded into controlled-release polymers and its pharmacokinetic properties were determined in vitro and in vivo by using a rabbit model of SAH. Methods. Ethylene—vinyl acetate copolymer (EVAc) was loaded 40% (w:w) with EBD and its pharmacokinetics were spectrophotometrically determined in vitro by examining three EBD—EVAc polymers. Additional polymers were implanted either into the frontal lobe or into the cisterna magna of 16 New Zealand White rabbits. Subarachnoid hemorrhage was induced in eight of the animals by an injection of 1.5 ml of arterial blood into the cisterna magna. The animals were killed 3 or 14 days postoperatively, their brains and spinal cords were harvested, and samples of each were placed in formamide for dye extraction and quantification. Specimens were examined macroscopically and the concentrations of EBD were determined with the aid of a spectrophotometer. The EBD—EVAc polymers continuously released EBD over a 133-day period. The controlled release of the dye into the subarachnoid space in either location resulted in staining of the entire central nervous system (CNS) in rabbits when the polymers were placed either on the frontal lobe or in the cisterna magna. The EBD diffusion covered a distance of at least 40 cm. The presence of blood in the subarachnoid space did not interfere with the diffusion. Conclusions. In this study the authors define the rate and extent of diffusion of EBD from controlled-release polymers placed in the subarachnoid space under conditions of SAH. Evans blue dye diffused through the entire rabbit CNS, covering a distance greater than that of the longest dimension of the hemicircumference of the subarachnoid space around the human brain. The pharmacokinetic properties of EBD—EVAc polymers are comparable to those of antivasospasm agents that are successfully used in animal models of SAH.


2002 ◽  
Vol 97 (2) ◽  
pp. 268-271 ◽  
Author(s):  
Atsuhiro Nakagawa ◽  
Ching-Chan Su ◽  
Kiyotaka Sato ◽  
Reizo Shirane

Object. Circulating blood volume (cBV) is reported to decrease in patients who suffer a subarachnoid hemorrhage (SAH), but little is known about the correlation between changes in cBV, and patient clinical condition and time course after SAH, especially during the very acute stage. To determine appropriate management of patients with SAH, the authors measured cBV by using pulse spectrophotometry immediately after patient admission. They also evaluated whether the timing of surgery influenced changes in cBV. Methods.Circulating blood volume was measured in a total of 73 patients who were divided into the following three groups: Group A (very acute SAH) consisted of 14 SAH cases, Group B (acute SAH) included 34 SAH cases, and Group C (controls) included 25 other neurosurgical cases. All patients in Group A underwent aneurysm clipping within 6 hours after onset of SAH, whereas all patients in Group B underwent aneurysm clipping within 72 hours after onset. Hypervolemic therapy was not performed in patients with SAH. Before surgery, cBV was significantly lower in patients in Group B than in those in Group C, but there was no significant difference in this parameter when comparing Groups A and C. Although there was a transient drop in cBV in Group B patients for at least 3 days after surgery, there was no significant change in cBV in Group A patients during the study period. None of the Group A patients suffered from symptomatic vasospasm; however, four Group B patients did experience symptomatic vasospasm. Conclusions. The authors assert that normovolemic fluid management is appropriate for patients who undergo surgery during the very acute stage of SAH, whereas a relatively hypervolemic therapy is necessary for 3 to 5 days after operation to prevent early hypovolemia in patients who undergo surgery during the acute stage of SAH.


1989 ◽  
Vol 71 (2) ◽  
pp. 233-238 ◽  
Author(s):  
Yukio Ikeda ◽  
Kiyomi Ikeda ◽  
Donlin M. Long

✓ Oxygen free radicals such as superoxide radical and iron-catalyzed hydroxyl radical generated by the superoxide system have been implicated in the genesis of brain edema. Therefore, deferoxamine (DFO), an iron chelator, could potentially be used to treat brain edema. To examine this hypothesis, vasogenic brain edema was produced in 48 cats by a cortical freezing lesion. The animals were separated into three groups: Group 1 comprised 14 cats that received no DFO and were sacrificed at 6 or 24 hours; Group 2 consisted of 12 cats that were treated with DFO (50 mg/kg/ml, intravenously) at 15 minutes before the lesion was made and 60 minutes later and were sacrificed at 6 or 24 hours; and Group 3 included 12 cats that were treated with DFO (50 mg/kg/ml, intravenously) at 15 minutes after the lesion was produced and 60 minutes later and were sacrificed at 6 or 24 hours. The effect of DFO on arterial blood pressure was also studied in the remaining 10 cats. Brain water content in eight sampling areas was measured by the specific gravity method. Blood-brain barrier disruption was assessed by spread of Evans blue dye with planimetry. Specific gravity values at 6 and 24 hours were significantly higher in Group 2 than in Group 1 animals. Areas of Evans blue dye extravasation at 6 and 24 hours were significantly reduced in Group 2 relative to Group 1. Group 3 cats showed improvement in specific gravity values and Evans blue extravasation at 6 hours, but not at 24 hours. The iron chelator DFO prevented early development of brain edema; thus, this oxygen free radical scavenger may provide a foundation for a new therapy for brain edema.


1972 ◽  
Vol 36 (5) ◽  
pp. 548-551 ◽  
Author(s):  
Iftikhar A. Raja

✓ Forty-two patients with aneurysm-induced third nerve palsy are described. After carotid ligation, 58% showed satisfactory and 42% unsatisfactory functional recovery. In some patients the deficit continued to increase even after carotid ligation. Early ligation provided a better chance of recovery of third nerve function. Patients in whom third nerve palsy began after subarachnoid hemorrhage had a poor prognosis. No relationship was noted between the size of the aneurysm and the recovery of third nerve function.


1977 ◽  
Vol 47 (1) ◽  
pp. 50-56 ◽  
Author(s):  
Hiroshi Matsumura ◽  
Yasumasa Makita ◽  
Kuniyuki Someda ◽  
Akinori Kondo

✓ We have operated on 12 of 14 cases of arteriovenous malformation (AVM) in the posterior fossa since 1968, with one death. The lesions were in the cerebellum in 10 cases (three anteromedial, one central, three lateral, and three posteromedial), and in the cerebellopontine angle in two; in two cases the lesions were directly related to the brain stem. The AVM's in the anterior part of the cerebellum were operated on through a transtentorial occipital approach.


1975 ◽  
Vol 42 (4) ◽  
pp. 457-461 ◽  
Author(s):  
Charles J. Hodge ◽  
Robert B. King

✓ The authors describe a patient with subarachnoid hemorrhage from an arteriovenous malformation of the choroid plexus and present a brief review of related reports.


1991 ◽  
Vol 74 (2) ◽  
pp. 270-277 ◽  
Author(s):  
Katsuji Shima ◽  
Anthony Marmarou

✓ The degree of brain-stem dysfunction associated with high-level fluid-percussion injury (3.0 to 3.8 atm) was investigated in anesthetized cats. Measurements were made of the animals' intracranial pressure (ICP), pressure-volume index (PVI), far-field brain-stem auditory evoked responses (BAER's), and cerebral blood flow (CBF). The animals were classified into two groups based on the severity of neuropathological damage to the brain stem after trauma: Group 1 had mild intraparenchymal and subarachnoid hemorrhages and Group 2 had severe intraparenchymal and subarachnoid hemorrhages. The ICP values in Group 1 were insignificantly lower than those in Group 2, while the PVI values in Group 2 were clearly lower (p < 0.05). Immediately after the injury, peaks II, III, and IV of the BAER's demonstrated a transitory and marked suppression. One Group 1 and two Group 2 animals showed the disappearance of peak V. In Group 1, the latencies of peak II, III, and IV gradually increased until 60 to 150 minutes postinjury, then returned to 95% of baseline value at 8 hours; however, the animals in Group 2 showed poor recovery of latencies. Two hours after brain injury, the CBF decreased to 40% of the preinjury measurement in both groups (p < 0.001). In contrast to Group 2, the CBF in Group 1 returned to 86.8% of the preinjury measurement by 8 hours following the injury. Changes in PVI, BAER, and CBF correlated well with the degree of brain-stem injury following severe head injury'- These data indicate that high-level fluid-percussion injury (> 3.0 atm) is predominantly a model of brain-stem injury.


1984 ◽  
Vol 61 (6) ◽  
pp. 1009-1028 ◽  
Author(s):  
Lindsay Symon ◽  
Janos Vajda

✓ A series of 35 patients with 36 giant aneurysms is presented. Thirteen patients presented following subarachnoid hemorrhage (SAH) and 22 with evidence of a space-occupying lesion without recent SAH. The preferred technique of temporary trapping of the aneurysm, evacuation of the contained thrombus, and occlusion of the neck by a suitable clip is described. The danger of attempted ligation in atheromatous vessels is stressed. Intraoperatively, blood pressure was adjusted to keep the general brain circulation within autoregulatory limits. Direct occlusion of the aneurysm was possible in over 80% of the cases. The mortality rate was 8% in 36 operations. Six percent of patients had a poor result. Considerable improvement in visual loss was evident in six of seven patients in whom this was a presenting feature, and in four of seven with disturbed eye movements.


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