Clinicopathological study of cerebral aneurysms

1978 ◽  
Vol 48 (4) ◽  
pp. 505-514 ◽  
Author(s):  
Jiro Suzuki ◽  
Hiro Ohara
Keyword(s):  
Endothelial Cells ◽  
Blood Flow ◽  
Cerebrospinal Fluid ◽  
Cerebral Arteries ◽  
Fibrous Tissue ◽  
Cerebral Aneurysms ◽  
Content Type ◽  
Clinicopathological Study ◽  
The Media ◽  
Fine Print

✓ The origin and mechanism of rupture, repair, and growth of intracranial saccular aneurysms are reported in an investigation of 45 aneurysms (23 unruptured and 22 ruptured) found in 34 brain specimens. Gaps in the media at the bifurcations of cerebral arteries are important for aneurysmal formation. The walls of aneurysms smaller than 3 mm in diameter are mainly composed of endothelial cells, and fibrous tissue. When aneurysms grow larger than 4 mm, the walls become collagenous and extremely thin portions develop in their domes, forming potential rupture points. Immediately after the rupture, bleeding is stopped by clot and a new fibrin layer is formed around the rupture point. It is proposed that the cerebrospinal fluid has a special accelerating action in clot formation. This fibrin layer is weak, and repeat rupture occurs within 3 weeks after the initial hemorrhage. However, after 3 weeks, rebleeding is rare due to the reinforcement of this layer, and capillaries appear in this new wall. Hemorrhages from these capillaries occur within and outside the new wall caused by the constant impingement of blood flow. In severe cases, the aneurysm ruptures again, but when the hemorrhages are slight, the aneurysm grows as the wall is thickened by repeated hemorrhages and their absorption. This may explain the growth mechanism of the aneurysm.

Norepinephrine in cerebrospinal fluid of patients with cerebral vasospasm

1982 ◽  
Vol 56 (3) ◽  
pp. 344-349 ◽  
Author(s):  
Taku Shigeno
Keyword(s):  
Cerebrospinal Fluid ◽  
Cerebral Arteries ◽  
Cerebral Aneurysms ◽  
Fluorometric Method ◽  
Content Type ◽  
Highly Sensitive ◽  
Secondary Phenomenon ◽  
Lumbar Cerebrospinal Fluid ◽  
The Brain ◽  
Fine Print

✓ The content of norepinephrine (NE) in the ventricular, basal cisternal, and lumbar cerebrospinal fluid (CSF) was determined in 19 patients with ruptured cerebral aneurysms at different intervals according to the presence or absence of vasospasm. Twelve were operated on within 3 days after subarachnoid hemorrhage (SAH), prior to the occurrence of vasospasm. Postoperatively, CSF was continuously drained from a basal cistern or lateral ventricle. Norepinephrine was assayed by the highly sensitive automated fluorometric method. The concentration of NE increased in all sites of CSF sampling along with the appearance of vasospasm. Above all, the cisternal CSF of patients with vasospasm contained significantly higher NE (0.246 ± 0.049 ng/ml, mean ± SEM) compared to those without vasospasm (0.075 ± 0.001 ng/ml) (p < 0.001). However, since this increase cannot be considered to be high enough locally to constrict cerebral arteries, this might be only a secondary phenomenon due to release of NE into CSF from various sources in the brain.

Effects of indomethacin and prostacyclin on isolated human pial arteries contracted by CSF from patients with aneurysmal SAH

1981 ◽  
Vol 55 (6) ◽  
pp. 877-883 ◽  
Author(s):  
Lennart Brandt ◽  
Bengt Ljunggren ◽  
Karl-Erik Andersson ◽  
Bengt Hindfelt ◽  
Tore Uski
Keyword(s):  
Cerebrospinal Fluid ◽  
Arachidonic Acid ◽  
Vessel Wall ◽  
Cerebral Arteries ◽  
Pial Arteries ◽  
Content Type ◽  
Cerebral Vasoconstriction ◽  
Arachidonic Acid Metabolites ◽  
Acid Metabolites ◽  
Fine Print

✓ In small human cerebral arteries preincubated with indomethacin, contractions induced by cerebrospinal fluid (CSF), from patients with subarachnoid hemorrhage were markedly increased. Also contractions induced by noradrenaline, but not 5-hydroxytryptamine, were augmented. Prostacyclin and its metabolite 6-keto-prostaglandin (PG)E1 reversed the contractions induced by CSF, as well as by noradrenaline, 5-hydroxytryptamine, and PGF2α. The findings suggest that these substances are able to counteract the influence of vasoconstrictor material in hemorrhagic CSF. If the capacity to synthesize these “protective” arachidonic acid metabolites is reduced, the resulting imbalance between contractile and relaxant forces acting on the vessel wall may lead to sustained cerebral vasoconstriction.

Real-time detection of vascular occlusion and reperfusion of the brain during surgery by using infrared imaging

2002 ◽  
Vol 96 (5) ◽  
pp. 918-923 ◽  
Author(s):  
Joseph C. Watson ◽  
Alexander M. Gorbach ◽  
Ryszard M. Pluta ◽  
Ramin Rak ◽  
John D. Heiss ◽  
...  
Keyword(s):  
Blood Flow ◽  
High Resolution ◽  
Real Time ◽  
Infrared Imaging ◽  
Cerebral Arteries ◽  
Infrared Camera ◽  
Collateral Flow ◽  
Content Type ◽  
The Brain ◽  
Fine Print

Object. Application of sensitive infrared imaging is ideally suited to observe blood vessels and blood flow in exposed organs, including the brain. Temporary vascular occlusion is an important part of neurosurgery, but the capacity to monitor the effects of these occlusions in real time is limited. In surgical procedures that require vascular manipulation, such as those involving aneurysms, arteriovenous malformations (AVMs), or tumors, the ability to visualize blood flow in vessels and their distribution beds would be beneficial. The authors recount their experience in the use of a sensitive (0.02°C), high-resolution (up to 50 µm/pixel) infrared camera with a rapid shutter speed (up to 2 msec/frame) for localizing cortical function intraoperatively. They observed high-resolution images of cerebral arteries and veins. The authors hypothesized that infrared imaging of cerebral arteries, performed using a sensitive, high-resolution camera during surgery, would permit changes in arterial flow to be be seen immediately, thus providing real-time assessment of brain perfusion in the involved vascular territory. Methods. Cynomolgus monkeys underwent extensive craniectomies, exposing the frontal, parietal, and temporal lobes. Temporary occlusions of the internal carotid artery and middle cerebral artery branches (30 events) were performed serially and were visualized with the aid of an infrared camera. Arteries and veins of the monkey brain were clearly visualized due to cooling of the exposed brain, which contrasted with blood within the vessels that remained at core temperature. Blood flow changes in vessels were seen immediately (< 1 second) in real time during occlusion and reopening of the vessels, regardless of the duration of the occlusion. Areas of decreased cortical blood flow rapidly cooled (−0.3 to 1.3°C) and reheated in response to reperfusion. Rewarming occurred faster in arteries than in the cortex (for a 20-minute occlusion, the change in temperature per second was 2 × 10−2°C in the artery and 7 × 10−3°C in the brain). Collateral flow could be evaluated by intraoperative observations and data processing. Conclusions. Use of high-resolution, digital infrared imaging permits real-time visualization of arterial flow. It has the potential to provide the surgeon with a means to assess collateral flow during temporary vessel occlusion and to visualize directly the flow in parent arteries or persistent filling of an aneurysm after clipping. During surgery for AVMs, the technique may provide a new way to assess arterial inflow, venous outflow, results of embolization, collateral flow, steal, and normal perfusion pressure breakthrough.

Cerebrospinal fluid may nourish cerebral vessels through pathways in the adventitia that may be analogous to systemic vasa vasorum

1982 ◽  
Vol 56 (4) ◽  
pp. 475-481 ◽  
Author(s):  
Nicholas T. Zervas ◽  
Theodore M. Liszczak ◽  
Marc R. Mayberg ◽  
Peter McL. Black
Keyword(s):  
Cerebrospinal Fluid ◽  
Blood Vessels ◽  
Subarachnoid Space ◽  
Cerebral Arteries ◽  
Cerebral Vessels ◽  
Vasa Vasorum ◽  
Cerebral Blood Vessels ◽  
Content Type ◽  
Large Proteins ◽  
Fine Print

✓ Cerebral blood vessels are devoid of vasa vasorum. Therefore, the authors have studied the microarchitecture of the adventitia of large feline cerebral vessels and systemic vessels of the same size, in an effort to determine how the vessels are nourished. The cerebral vessels contain a rete vasorum in the adventitia that is permeable to large proteins and is in continuity with the subarachnoid space. This substructure may be analogous to the systemic vasa vasorum and may contribute to the nutrition of the cerebral arteries.

Source and cause of endothelin-1 release into cerebrospinal fluid after subarachnoid hemorrhage

1997 ◽  
Vol 87 (2) ◽  
pp. 287-293 ◽  
Author(s):  
Ryszard M. Pluta ◽  
Robert J. Boock ◽  
John K. Afshar ◽  
Kathleen Clouse ◽  
Mima Bacic ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cerebrospinal Fluid ◽  
Subarachnoid Hemorrhage ◽  
Cerebral Ischemia ◽  
Cerebral Vasospasm ◽  
Plasma Levels ◽  
Transient Cerebral Ischemia ◽  
Content Type ◽  
Endothelin 1 ◽  
Fine Print

✓ Despite years of research, delayed cerebral vasospasm remains a serious complication of subarachnoid hemorrhage (SAH). Recently, it has been proposed that endothelin-1 (ET-1) mediates vasospasm. The authors examined this hypothesis in a series of experiments. In a primate model of SAH, serial ET-1 levels were measured in samples from the perivascular space by using a microdialysis technique and in cerebrospinal fluid (CSF) and plasma during the development and resolution of delayed vasospasm. To determine whether elevated ET-1 production was a direct cause of vasospasm or acted secondary to ischemia, the authors also measured ET-1 levels in plasma and CSF after transient cerebral ischemia. To elucidate the source of ET-1, they measured its production in cultures of endothelial cells and astrocytes exposed to oxyhemoglobin (10 µM), methemoglobin (10 µM), or hypoxia (11% oxygen). There was no correlation between the perivascular levels of ET-1 and the development of vasospasm or its resolution. Cerebrospinal fluid and plasma levels of ET-1 were not affected by vasospasm (CSF ET-1 levels were 9.3 ± 2.2 pg/ml and ET-1 plasma levels were 1.2 ± 0.6 pg/ml) before SAH and remained unchanged when vasospasm developed (7.1 ± 1.7 pg/ml in CSF and 2.7 ± 1.5 pg/ml in plasma). Transient cerebral ischemia evoked an increase of ET-1 levels in CSF (1 ± 0.4 pg/ml at the occlusion vs. 3.1 ± 0.6 pg/ml 4 hours after reperfusion; p < 0.05), which returned to normal (0.7 ± 0.3 pg/ml) after 24 hours. Endothelial cells and astrocytes in culture showed inhibition of ET-1 production 6 hours after exposure to hemoglobins. Hypoxia inhibited ET-1 release by endothelial cells at 24 hours (6.4 ± 0.8 pg/ml vs. 0.1 ± 0.1 pg/ml, control vs. hypoxic endothelial cells; p < 0.05) and at 48 hours (6.4 ± 0.6 pg/ml vs. 0 ± 0.1 pg/ml, control vs. hypoxic endothelial cells; p < 0.05), but in astrocytes hypoxia induced an increase of ET-1 at 6 hours (1.5 ± 0.6 vs. 6.4 ± 1.1 pg/ml, control vs. hypoxic astrocytes; p < 0.05). Endothelin-1 is released from astrocytes, but not endothelial cells, during hypoxia and is released from the brain after transient ischemia. There is no relationship between ET-1 and vasospasm in vivo or between ET-1 and oxyhemoglobin, a putative agent of vasospasm, in vitro. The increase in ET-1 levels in CSF after SAH from a ruptured intracranial aneurysm appears to be the result of cerebral ischemia rather than reflecting the cause of cerebral vasospasm.

Cerebral aneurysms following radiotherapy for medulloblastoma

1989 ◽  
Vol 70 (4) ◽  
pp. 545-550 ◽  
Author(s):  
Peter J. Benson ◽  
Joo Ho Sung
Keyword(s):  
Cerebral Arteries ◽  
Cerebral Aneurysms ◽  
Content Type ◽  
Histological Features ◽  
Autopsy Examination ◽  
Cerebellar Medulloblastoma ◽  
Radiation Induced ◽  
The Brain ◽  
Fine Print ◽  
Saccular Aneurysms

✓ Three patients, two males and one female aged 21, 14, and 31 years, respectively, developed cerebral saccular aneurysms several years after undergoing radiotherapy for cerebellar medulloblastoma at 2, 5, and 14 years of age, respectively. Following surgery, all three received combined cobalt-60 irradiation and intrathecal colloidal radioactive gold (198Au) therapy, and died from rupture of the aneurysm 19, 9, and 17 years after the radiotherapy, respectively. Autopsy examination revealed no recurrence of the medulloblastoma, but widespread radiation-induced vasculopathy was found at the base of the brain and in the spinal cord, and saccular aneurysms arose from the posterior cerebral arteries at the basal cistern or choroidal fissure. The aneurysms differed from the ordinary saccular aneurysms of congenital type in their location and histological features. Their locations corresponded to the areas where intrathecally administered colloidal 198Au is likely to pool, and they originated directly from a segment of the artery rather than from a branching site as in congenital saccular aneurysms. It is, therefore, concluded that the aneurysms in these three patients were most likely radiation-induced.

Potassium and the pathogenesis of cerebral arterial spasm in dog and man

1971 ◽  
Vol 35 (1) ◽  
pp. 45-50 ◽  
Author(s):  
Robert H. Wilkins ◽  
Philip Levitt
Keyword(s):  
Cerebrospinal Fluid ◽  
Subarachnoid Hemorrhage ◽  
Cerebral Arteries ◽  
Arterial Spasm ◽  
Content Type ◽  
Blood Clots ◽  
The Individual ◽  
Fine Print

✓ This study investigates the possibility that the intracranial arterial spasm occurring in patients with subarachnoid hemorrhage might be due to potassium released from blood clots surrounding the involved cerebral arteries. Although cerebral arterial spasm could be induced in the dog by the injection of potassium into the chiasmatic cistern, it only occurred with potassium concentrations higher than those expected to result from hemolysis of subarachnoid clots. Furthermore, the potassium concentrations were not elevated in the cerebrospinal fluid of human patients with subarachnoid hemorrhage, and the individual potassium values could not be correlated with the presence or degree of spasm encountered in these patients.

Changes in periventricular vasculature of rabbit brain following induction of hydrocephalus and after shunting

1988 ◽  
Vol 69 (1) ◽  
pp. 115-120 ◽  
Author(s):  
Marc R. Del Bigio ◽  
J. Edward Bruni
Keyword(s):  
Blood Flow ◽  
Cerebrospinal Fluid ◽  
Cerebral Blood Flow ◽  
Corpus Callosum ◽  
Blood Vessel ◽  
Silicone Oil ◽  
Rabbit Brain ◽  
Content Type ◽  
Cerebrospinal Fluid Shunting ◽  
Fine Print

✓ Hydrocephalus was induced in rabbits by injection of silicone oil into the cisterna magna. At 1 and 8 weeks postinjection the rabbits were either sacrificed or treated by cerebrospinal fluid shunting for 1 week. Blood vessel profiles in the periventricular neuropil were examined by light microscopy. In the caudate nucleus, septal area, and corpus callosum, hydrocephalus caused a reduction in the number of capillaries but no changes were observed in the number of larger blood vessels. Shunting reduced the size of the ventricles to normal and the number of capillaries increased if hydrocephalus was present for 1 week prior to shunting. If hydrocephalus was present for 8 weeks prior to shunting, the number of capillaries did not increase. These observations support the concept that collapse of capillaries may account for the decreased cerebral blood flow that has been measured in hydrocephalic brains.

Computerized tomography angiography of ruptured cerebral aneurysms: factors affecting time to maximum contrast concentration

1998 ◽  
Vol 88 (4) ◽  
pp. 663-669 ◽  
Author(s):  
Yoshikazu Nakajima ◽  
Toshiki Yoshimine ◽  
Hiroyoshi Yoshida ◽  
Keiji Sakashita ◽  
Mitsutoyo Okamoto ◽  
...  
Keyword(s):  
Time Delay ◽  
Ct Angiography ◽  
Computerized Tomography ◽  
Cavernous Sinus ◽  
Cardiopulmonary Arrest ◽  
Cerebral Arteries ◽  
Cerebral Aneurysms ◽  
Volume Data ◽  
Content Type ◽  
Fine Print

Object. This study was conducted to assess the diagnostic value of three-dimensional computerized tomography (3-D CT) angiography in demonstrating cerebral aneurysms in 42 consecutive patients presenting with acute subarachnoid hemorrhage (SAH). Methods. To obtain the volume data for selective visualization of the cerebral arteries without enhancement of the venous system, the time delay was established between the injection of contrast medium and the start of scanning by using two different methods. The circulation time was calculated with Schad's formula in the first 13 cases, but the results were not satisfactory. In the 29 subsequent cases the time delay was established using a single-level dynamic CT prescan. The dynamic prescan demonstrated the statistical differences in peak time with regard to patient age, SAH grade, and the postresuscitation state after cardiopulmonary arrest. The 3-D CT angiograms were generated from the volume data by using a voxel transmission method. Computerized tomography angiography obtained after optimally adjusted time delay demonstrated the contour of the cerebral arteries in 97% of cases, and aneurysms were detected in 93%. Enhancement of the cavernous sinus and major cortical veins was avoided. Even in patients who suffered cardiopulmonary arrest, images of the major arteries were clearly demonstrated after resuscitation. Conclusions. In an emergency situation, CT angiography with a dynamic prescan may be an alternative to magnetic resonance angiography or digital subtraction angiography in the diagnosis of ruptured aneurysms. This modality would also be useful for the precise assessment of small aneurysms, blebs, and aneurysms adjacent to the cavernous sinus.

Cerebral vasospasm and ultrastructural changes in cerebral arterial wall

1978 ◽  
Vol 49 (2) ◽  
pp. 229-238 ◽  
Author(s):  
Yusuke Tanabe ◽  
Kazuki Sakata ◽  
Hiromu Yamada ◽  
Takao Ito ◽  
Mitsuaki Takada
Keyword(s):  
Endothelial Cells ◽  
Arterial Wall ◽  
Ultrastructural Changes ◽  
Intimal Thickening ◽  
Cell Debris ◽  
Content Type ◽  
Dense Bodies ◽  
The Media ◽  
Ultrastructural Findings ◽  
Fine Print

✓ Subarachnoid hemorrhage (SAH) was produced experimentally by injecting normal dog's blood as well as reserpinized dog's blood into the chiasmal cistern of the dog. The following observations were made: 1) After SAH with normal dog's blood, the intima of the basal truncal arterial wall showed some or all of such ultrastructural changes as appearance of vacuoles and dense bodies in endothelial cells, detachment of endothelial cells, appearance of intimal cells, and intimal thickening. The changes first appeared 2 hours after SAH, culminated at 3 to 7 days after SAH, and persisted up to 1 month after SAH. 2) After SAH with normal dog's blood, the media of the basal truncal arterial wall showed some or all of such ultrastructural changes as moth-eaten contour of muscle cells, appearance of intracytoplasmic vacuoles and dense bodies, appearance of cell debris, enlargement of interstitial space, and appearance therein of dense particles. These findings, which, in short, are to be expressed as myonecrosis and its repairing process, first appeared 2 hours after SAH, culminated at 1 to 4 months after SAH, and persisted up to 1 year after SAH. 3) Three and 5 days following SAH with reserpinized dog's blood, ultrastructural findings of the intima and media of the basal truncal arterial wall were entirely normal. On the basis of the above findings, it was concluded that the ultrastructural changes in the cerebral arterial wall observed after SAH with normal dog's blood occurred as a consequence of vasospasm. The possibility that late spasm, in turn, might be facilitated by myonecrosis, could not be denied.

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