Surgical manipulation of primate cerebral arteries in established vasospasm

1991 ◽  
Vol 75 (3) ◽  
pp. 425-432 ◽  
Author(s):  
J. Max Findlay ◽  
R. Loch Macdonald ◽  
Bryce K. A. Weir ◽  
Michael G. A. Grace
Keyword(s):  
Cerebral Ischemia ◽  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Cerebral Arteries ◽  
Circle Of Willis ◽  
Content Type ◽  
Increased Risk ◽  
The Right ◽  
Surgical Manipulation ◽  
Fine Print

✓ It is generally believed that surgery in the face of angiographic vasospasm is dangerous due to an increased incidence of postoperative cerebral ischemia. One theory is that arterial narrowing is exacerbated by surgical manipulation of vasospastic vessels during aneurysm dissection and clipping. This theory was tested in a primate model of cerebral vasospasm and the results reported. Six monkeys underwent baseline cerebral angiography, followed by induction of subarachnoid hemorrhage (SAH) on both sides of the circle of Willis. An equal amount of fresh autologous blood clot was placed around each internal carotid, anterior cerebral, and middle cerebral artery. Six days later, angiography was repeated and the right craniectomy was reopened for clot evacuation and surgical manipulation of the right cerebral arteries, including placement of a temporary aneurysm clip on the right middle cerebral artery. The left cerebral arteries were not exposed or manipulated, and served as controls. Twenty-four hours later angiography was repeated, then the animals were killed. Equal and significant vasospasm (> 40% reduction in vessel caliber compared to baseline, p < 0.05) was seen in the middle cerebral arteries on both sides of the circle of Willis in all animals 6 and 7 days after SAH. There was no significant change in the severity of vasospasm on Day 7 compared with Day 6 in the right cerebral arteries. Increased risk of postoperative cerebral ischemia for surgery in the peak vasospasm period may be due to mechanisms other than increased arterial narrowing precipitated by surgical manipulation.

Heparin reduces proliferative angiopathy following subarachnoid hemorrhage in cats

1985 ◽  
Vol 62 (4) ◽  
pp. 570-575 ◽  
Author(s):  
John P. Kapp ◽  
Ben R. Clower ◽  
Frederick M. Azar ◽  
Nobuyoshi Yabuno ◽  
Robert R. Smith
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Growth Factor ◽  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Cerebral Arteries ◽  
Platelet Derived Growth Factor ◽  
Platelet Factor ◽  
Content Type ◽  
The Right ◽  
Fine Print

✓ Subarachnoid hemorrhage (SAH) was produced in cats by transorbital rupture of the right middle cerebral artery (MCA). In untreated cats, widespread proliferative angiopathy occurred in both MCA's by 16 days after SAH. In cats that received systemic heparin, the pathological events following SAH were clearly reduced in the ruptured artery, and were not present in the contralateral left MCA. Platelets are known to adhere to the subintimal surface of cerebral arteries after SAH. The authors suggest that platelet-derived growth factor released from the intimal platelet carpet following SAH may be the stimulus for the development of proliferative angiopathy, and that this platelet factor is inhibited by heparin.

Bifurcation geometry and the presence of cerebral artery aneurysms

2004 ◽  
Vol 101 (1) ◽  
pp. 108-113 ◽  
Author(s):  
Tor Ingebrigtsen ◽  
Michael K. Morgan ◽  
Ken Faulder ◽  
Linda Ingebrigtsen ◽  
Trygve Sparr ◽  
...  
Keyword(s):  
Cerebral Artery ◽  
Geometric Model ◽  
Cerebral Arteries ◽  
Multivariate Logistic Regression Analysis ◽  
Circle Of Willis ◽  
Parent Vessel ◽  
Content Type ◽  
Optimality Principles ◽  
The Relationship ◽  
Fine Print

Object. The angles of arterial bifurcations are governed by principles of work minimization (optimality principle). This determines the relationship between the angle of a bifurcation and the radii of the vessels. Nevertheless, the model is predicated on an absence of significant communication between these branches. The circle of Willis changes this relationship because the vessels proximal to the ring of vessels have additional factors that determine work minimization compared with more distal branches. This must have an impact on understanding of the relationship between shear stress and aneurysm formation. The authors hypothesized that normal bifurcations of cerebral arteries beyond the circle of Willis would follow optimality principles of minimum work and that the presence of aneurysms would be associated with deviations from optimum bifurcation geometry. Nevertheless, the vessels participating in (or immediately proximal to) the circle of Willis may not follow the geometric model as it is generally applied and this must also be investigated. Methods. One hundred seven bifurcations of the middle cerebral artery (MCA), distal internal carotid artery (ICA), and basilar artery (BA) were studied in 55 patients. The authors analyzed three-dimensional reconstructions of digital subtraction angiography images with respect to vessel radii and bifurcation angles. The junction exponent (that is, a calculated measure of the division of flow at the bifurcation) and the difference between the predicted optimal and observed branch angles were used as measures of deviation from the geometry thought best to minimize work. The mean junction exponent for MCA bifurcations was 2.9 ± 1.2 (mean ± standard deviation [SD]), which is close to the theoretical optimum of 3, but it was significantly smaller (p < 0.001; 1.7 ± 0.8, mean ± SD) for distal ICA bifurcations. In a multilevel multivariate logistic regression analysis, only the observed branch angles were significant independent predictors for the presence of an aneurysm. The odds ratio (OR) (95% confidence interval) for the presence of an aneurysm was 3.46 (1.02–11.74) between the lowest and highest tertile of the observed angle between the parent vessel and the largest branch. The corresponding OR for the smallest branch was 48.06 (9.7–238.2). Conclusions. The bifurcation beyond the circle of Willis (that is, the MCA) closely approximated optimality principles, whereas the bifurcations within the circle of Willis (that is, the distal ICA and BA) did not. This indicates that the confluence of hemodynamic forces plays an important role in the distribution of work at bifurcations within the circle of Willis. In addition, the observed branch angles were predictors for the presence of aneurysms.

Thresholds of focal cerebral ischemia in awake monkeys

1981 ◽  
Vol 54 (6) ◽  
pp. 773-782 ◽  
Author(s):  
Thomas H. Jones ◽  
Richard B. Morawetz ◽  
Robert M. Crowell ◽  
Frank W. Marcoux ◽  
Stuart J. FitzGibbon ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Ischemia ◽  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Focal Cerebral Ischemia ◽  
Neurological Function ◽  
Local Flow ◽  
Content Type ◽  
Mca Occlusion ◽  
Fine Print

✓ An awake-primate model has been developed which permits reversible middle cerebral artery (MCA) occlusion during physiological monitoring. This method eliminates the ischemia-modifying effects of anesthesia, and permits correlation of neurological function with cerebral blood flow (CBF) and neuropathology. The model was used to assess the brain's tolerance to focal cerebral ischemia. The MCA was occluded for 15 or 30 minutes, 2 to 3 hours, or permanently. Serial monitoring evaluated neurological function, local CBF (hydrogen clearance), and other physiological parameters (blood pressure, blood gases, and intracranial pressure). After 2 weeks, neuropathological evaluation identified infarcts and their relation to blood flow recording sites. Middle cerebral artery occlusion usually caused substantial decreases in local CBF. Variable reduction in flow correlated directly with the variable severity of deficit. Release of occlusion at up to 3 hours led to clinical improvement. Pathological examination showed microscopic foci of infarction after 15 to 30 minutes of ischemia, moderate to large infarcts after 2 to 3 hours of ischemia, and in most cases large infarcts after permanent MCA occlusion. Local CBF appeared to define thresholds for paralysis and infarction. When local flow dropped below about 23 cc/100 gm/min, reversible paralysis occurred. When local flow fell below 10 to 12 cc/100 gm/min for 2 to 3 hours or below 17 to 18 cc/100 gm/min during permanent occlusion, irreversible local damage was observed. These studies imply that some cases of acute hemiplegia, with blood flow in the paralysis range, might be improved by surgical revascularization. Studies of local CBF might help identify suitable cases for emergency revascularization.

Bilateral innervation of the cerebral arteries by the superior cervical ganglion in cats

1980 ◽  
Vol 53 (1) ◽  
pp. 88-91 ◽  
Author(s):  
Jesús Marín ◽  
Mercedes Salaices ◽  
Fernando Rivilla ◽  
Javier Burgos ◽  
Emilio J. Marco
Keyword(s):  
Cerebral Artery ◽  
Superior Cervical Ganglion ◽  
Anterior Cerebral Artery ◽  
Contractile Response ◽  
Cerebral Arteries ◽  
The Other ◽  
Content Type ◽  
Cervical Ganglion ◽  
The Right ◽  
Fine Print

✓ The effect of removal of the left superior cervical ganglion on the contractile response to norepinephrine (NE) and 5-hydroxytryptamine (5-HT, serotonin) was studied in isolated segments of the middle cerebral artery (MCA) and posterior communicating artery (PCoA) of the cat. Fifteen days after the excision, each dose of NE elicited a potentiated response in both the MCA and the PCoA, whichever side they originated. By contrast, 5-HT induced enhanced vasoconstriction at each dose only in the MCA and PCoA from the left side. When segments of MCA and PCoA from the right side were challenged against 5-HT, a significantly increased response was found only at the first three doses. On the other hand, the NE content of pools made of MCA, PCoA, and anterior cerebral artery from each side was reduced to the same level on both sides after ganglion removal. These results indicate that the excised superior cervical ganglion innervated the MCA and PCoA from both sides of the circle of Willis.

Traumatic occlusion of the middle cerebral artery

1973 ◽  
Vol 39 (6) ◽  
pp. 753-756 ◽  
Author(s):  
Charles R. Loar ◽  
William M. Chadduck ◽  
G. Robert Nugent
Keyword(s):  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Content Type ◽  
Complete Occlusion ◽  
Motorcycle Accident ◽  
The Right ◽  
Fine Print

✓ A case is reported of a patient rendered unconscious in a motorcycle accident. After a 6-hour lucid interval, he became unconscious again, and a left hemiplegia was noted. Arteriography demonstrated complete occlusion of the right middle cerebral artery. Comparable reported cases and theories of pathogenesis are discussed.

Loss of nitric oxide synthase immunoreactivity in cerebral vasospasm

1996 ◽  
Vol 84 (4) ◽  
pp. 648-654 ◽  
Author(s):  
Ryszard M. Pluta ◽  
B. Gregory Thompson ◽  
Ted M. Dawson ◽  
Solomon H. Snyder ◽  
Robert J. Boock ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Cerebral Vasospasm ◽  
Cerebral Artery ◽  
Cerebral Arteries ◽  
Nerve Fibers ◽  
Content Type ◽  
The Right ◽  
Oxide Synthase ◽  
Fine Print

✓ To determine the distribution of nitric oxide synthase (NOS) in the primate cerebral artery nervi vasorum and to examine the potential role of NOS in cerebral vasospasm after subarachnoid hemorrhage (SAH) in primates, the distribution of NOS immunoreactivity (NOS-IR) in the major cerebral arteries was examined immunohistochemically in cynomolgus monkeys by the use of whole, mounted preparations of the circle of Willis. In four normal monkeys, NOS-IR was localized to the endothelial and adventitial layers of the large cerebral arteries. On the abluminal side, NOS-IR staining was densely concentrated in perivascular nerve fibers (nervi vasorum) of the anterior circulation. Staining was less prominent in the posterior circulation. In six monkeys with vasospasm on Day 7 after placement of preclotted arterial blood to form an SAH around the right middle cerebral artery (MCA) (42% ± 8.3% decrease of MCA area, mean ± standard deviation), NOS-IR was virtually absent in nerve fibers around the spastic right MCA but was normal on the contralateral side. In five monkeys in which vasospasm resolved by Day 14 after SAH (36% ± 14% decrease of right MCA area on Day 7, and 5% ± 14% decrease on Day 14), NOS-IR was also absent in the right MCA adventitial nerve fibers and remained normal in the left MCA. Adventitial NOS-IR was also normal in cerebral vessels of a sham-operated, nonspastic monkey. These findings provide further evidence that nitric oxide (NO) functions as a neuronal transmitter to mediate vasodilation in primates and indicate a role for adventitial NO in the pathogenesis of cerebral vasospasm after SAH in humans.

Suboptimum hemicraniectomy as a cause of additional cerebral lesions in patients with malignant infarction of the middle cerebral artery

2001 ◽  
Vol 94 (5) ◽  
pp. 693-696 ◽  
Author(s):  
Simone Wagner ◽  
Holger Schnippering ◽  
Alfred Aschoff ◽  
James A. Koziol ◽  
Stefan Schwab ◽  
...  
Keyword(s):  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Maximum Diameter ◽  
Cerebral Lesions ◽  
Content Type ◽  
Associated Lesions ◽  
Risk Of Mortality ◽  
Malignant Infarction ◽  
Increased Risk ◽  
Fine Print

Object. The goal of this study was to determine the frequency of hemicraniectomy-associated lesions and their potential effect on the risk of mortality in patients suffering from malignant infarction of the middle cerebral artery (MCA). Methods. The authors evaluated serial computerized tomography scans obtained in 60 patients with complete infarction of the right MCA who were treated using hemicraniectomy. The maximum diameter of the hemicraniectomy was determined and the hemicraniectomy-associated lesions were classified as ischemic lesions or hemorrhages. The category of hemorrhages was composed of parenchymal, subdural, or epidural/subgaleal hematomas. Parenchymal hemorrhages and infarcts associated with hemicraniectomy occurred with frequency rates of 41.6% and 28.4%, respectively. The occurrence of hemicraniectomy-associated bleeding was related to the size of the hemicraniectomy performed; that is, the smaller the hemicraniectomy, the more often lesions occurred (p < 0.05). Hemicraniectomy-associated bleeding was also related to an increased risk of mortality. Conclusions. Hemicraniectomy is an effective therapy in patients with malignant infarction of the MCA. However, a hemicraniectomy that is too small in diameter may cause the formation of additional lesions and adversely affect the risk of mortality and the quality of survival. In addition, the size and shape of the edges of the bone defect are important factors relating to its efficacy.

Giant aneurysm of the middle cerebral artery containing an important blood channel

1972 ◽  
Vol 37 (3) ◽  
pp. 352-356 ◽  
Author(s):  
Hideo Terao ◽  
Isao Muraoka
Keyword(s):  
Cerebral Infarction ◽  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Giant Aneurysm ◽  
Content Type ◽  
The Right ◽  
Fine Print

✓ An enormous globoid aneurysm arising from the right middle cerebral artery is reported. A functioning blood channel ran through the laminated thrombus within the aneurysm, and operative injury to this blood channel caused serious cerebral infarction.

Angiographic evaluation of middle cerebral artery reperfusion caused by platelet glycoprotein IIb/IIIa receptor complex antagonist murine 7E3 F(ab')2 in a model of focal cerebral ischemia in rats

2001 ◽  
Vol 94 (4) ◽  
pp. 582-588 ◽  
Author(s):  
Yi Yang ◽  
Qiu Li ◽  
Marian T. Nakada ◽  
Tao Yang ◽  
Ashfaq Shuaib
Keyword(s):  
Cerebral Ischemia ◽  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Focal Cerebral Ischemia ◽  
Infarct Volume ◽  
Platelet Glycoprotein ◽  
Therapeutic Effects ◽  
Receptor Complex ◽  
Content Type ◽  
Fine Print

Object. Antagonists of the glycoprotein IIb/IIIa (GPIIb/IIIa) receptor complex are currently used for the treatment of acute coronary syndromes. The platelet GPIIb/IIIa mediates platelet aggregation, and blocking this receptor complex can reduce or prevent arterial thrombosis. To study the recanalization efficacy of a GPIIb/IIIa antagonist in treating cerebral ischemia, we investigated the therapeutic effects of murine 7E3 F(ab′)2 in a focal embolic cerebral ischemia model in rats. Methods. Focal cerebral ischemia was produced by introducing an autologous thrombus into the right side of the middle cerebral artery (MCA). Thirty male Wistar rats were randomly divided into three groups of 10 rats each: control, 7E3 F(ab′)2 administered 1 hour postischemia, and 7E3 F(ab′)2 administered 3 hours postischemia. Animals in the therapeutic groups received intravenous infusion of 6 mg/kg 7E3 F(ab′)2 at 1 or 3 hours following cerebral embolization. Brain infarct volume, neurobehavioral scores, duration of bleeding, and findings on angiograms of the MCA (before and after infusion) were assessed in all animals. Angiographic evaluation revealed full MCA recanalization in three of 10 animals in each 7E3 F(ab′)2 treatment group. Animals in these groups exhibited a significant reduction in infarct volume when compared with animals in the control group: 1) infarct volume 1 hour postischemia, 22 ± 13.9% (p = 0.005); 2) infarct volume 3 hours postischemia, 22.1 ± 14.8% (p = 0.008); and 3) infarct volume in control animals, 42.4 ± 16%. Postischemia treatment with 7E3 F(ab′)2 also improved the animal's neurobehavioral performance. The duration of bleeding significantly increased by more than two times, but there was no associated increase in intracerebral hemorrhage in any group. Conclusions. On the basis of their findings, the authors conclude that murine 7E3 F(ab′)2 is a potent and safe antiplatelet agent in this experimental focal embolic cerebral ischemia model. Neuronal lesions were significantly reduced when the treatment was delayed up to 3 hours.

Cerebral dissecting aneurysm and intimal fibroelastic thickening of cerebral arteries

1982 ◽  
Vol 56 (4) ◽  
pp. 571-576 ◽  
Author(s):  
Tomohiko Mizutani ◽  
Herbert I. Goldberg ◽  
Justin Parr ◽  
Clive Harper ◽  
Carson J. Thompson
Keyword(s):  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Cerebral Arteries ◽  
Dissecting Aneurysm ◽  
The Other ◽  
Left Middle Cerebral Artery ◽  
Similar Distribution ◽  
Content Type ◽  
Left Middle ◽  
Fine Print

✓ A 19-year-old white man developed aphasia and right hemiplegia after several falls while waterskiing. Cerebral angiography displayed a ripple appearance and a “string of beads” sign along the left middle cerebral artery, with occlusion or stenosis of most of its branches. The patient died after 6 days, of transtentorial herniation due to massive left cerebral infarction. At necropsy, the infarct was found to be due to a subintimal dissecting aneurysm of the left middle cerebral artery. Multifocal areas of intimal fibroelastic thickening (IFT) were found not only at the site of dissection, but also in the other cerebral arteries, most prominent at the bifurcations of the vessels. A systematic study of cerebral arteries performed in six control cases revealed that IFT was present in a similar distribution to that seen in the patient described. However, the degree of IFT in this patient was greater than in the controls. Some individuals with excessive IFT may be more susceptible to cerebral dissecting aneurysm under a variety of stresses, especially trauma.

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