scholarly journals Pregnancy Causes Diminished Myogenic Tone and Outward Hypotrophic Remodeling of the Cerebral Vein of Galen

2013 ◽  
Vol 33 (4) ◽  
pp. 542-542 ◽  
Author(s):  
Anne-Eva van der Wijk ◽  
Malou PH Schreurs ◽  
Marilyn J Cipolla
Keyword(s):  
Cerebral Arteries ◽  
Venous Blood ◽  
Blood Stasis ◽  
Wall Stress ◽  
Myogenic Tone ◽  
Cerebral Vein ◽  
Cerebral Veins ◽  
Vein Of Galen ◽  
First Time ◽  
Serotonergic Innervation

Pregnancy increases the risk of several complications associated with the cerebral veins, including thrombosis and hemorrhage. In contrast to the cerebral arteries and arterioles, few studies have focused on the effect of pregnancy on the cerebral venous side. Here, we investigated for the first time the effect of pregnancy on the function and structure of the cerebral vein of Galen in rats. Our major finding was that cerebral veins from late-pregnant (LP, n = 11) rats had larger lumen diameters and thinner walls than veins from nonpregnant (NP, n = 13) rats, indicating that pregnancy caused outward hypotrophic remodeling of the vein of Galen. Moreover, veins from NP animals had a small amount of myogenic tone at 10 mm Hg (3.9 ± 1.0%) that was diminished in veins during pregnancy (0.8 ± 0.3%; P < 0.01). However, endothelium-dependent and -independent vasodilation of the veins was unchanged during pregnancy. Using immunohistochemistry, we show that the vein of Galen receives perivascular innervation, and that serotonergic innervation of cerebral veins is significantly higher in veins from LP animals. Outward hypotrophic remodeling and diminished tone of cerebral veins during pregnancy may contribute to the development of venous pathology through elevated wall tension and wall stress, and possibly by promoting venous blood stasis.

Deep venous communication in vein of Galen malformations: incidence, Imaging, and Implications for treatment

2020 ◽  
pp. neurintsurg-2020-016224
Author(s):  
Hans Kortman ◽  
Ershad Navaei ◽  
Charles A Raybaud ◽  
Kartik Dev Bhatia ◽  
Manohar Shroff ◽  
...  
Keyword(s):  
Endovascular Treatment ◽  
Venous Drainage ◽  
Cerebral Vein ◽  
Cerebral Veins ◽  
Vein Of Galen ◽  
Mri Imaging ◽  
Alternative Pathways ◽  
Sagittal Sinus ◽  
Drainage Patterns ◽  
Optimal Quality

BackgroundFailure to appreciate deep venous drainage pathways is a major cause of severe complications in the endovascular treatment of vein of Galen aneurysmal malformations (VOGMs).ObjectiveTo report deep venous drainage patterns in patients with VOGM, emphasizing the internal cerebral veins, and to describe the challenges in evaluating these.MethodsPatients with VOGM presenting to our institute between 2000 and 2018 were retrospectively analyzed. Patients with complete and good quality imaging datasets were included in the study. Three neuroradiologists with expertise in the subject independently analyzed the deep venous drainage patterns on multi-sequence MRI and digital subtraction angiography. Follow-up imaging studies were analyzed for alterations in deep venous drainage patterns that occurred following endovascular treatment. Descriptive statistics were used to report findings.ResultsTwenty-three patients had optimal quality MRI imaging and 25 had optimal quality DSA imaging available. In 14/23 (61%) patients, internal cerebral vein (ICV) communication could be reliably identified on MRI and in 8/25 (32%) patients on DSA. Deep venous communication with the VOGM was demonstrated in 8/26 (30.8%) patients. One (3.8%) patient demonstrated ICV communication with the VOGM only on postoperative imaging, while in 2 (8%) patients the ICV drainage route changed from VOGM to alternative pathways after the procedure. Other variant pathways included lateral mesencephalic vein, superior or inferior sagittal sinus, anterior mesencephalic vein, tentorial sinus, deep Sylvian vein, and superior vermian vein.ConclusionICV communication with the VOGM is not uncommon and requires dedicated preprocedural imaging to identify it. However, there are significant challenges in assessing this communication in the presence of high-flow fistulae, vessel tortuosity and size, and contrast limitations in this population.

Microsurgical anatomy of the great cerebral vein of Galen and its tributaries

2003 ◽  
Vol 99 (6) ◽  
pp. 1028-1038 ◽  
Author(s):  
Patrick Chaynes
Keyword(s):  
Venous Drainage ◽  
Pineal Region ◽  
Surgical Approaches ◽  
Cerebral Vein ◽  
Cerebral Veins ◽  
Microsurgical Anatomy ◽  
Vein Of Galen ◽  
Content Type ◽  
Deep Cerebral Veins ◽  
Fine Print

Object. The deep cerebral veins may pose a major obstacle in operative approaches to deep-seated lesions, especially in the pineal region where multiple veins converge on the great cerebral vein of Galen. Because undesirable sequelae may occur from such surgery, the number of veins and branches to be sacrificed during these approaches should kept to a minimum. The purpose of this study was to examine venous drainage into the vein of Galen with a view to surgical approaches. If a vein hampering surgical access must be sacrificed, it can therefore be selected according to the smallest draining territory. Methods. The deep cerebral veins and their surrounding neural structures were examined in 50 cerebral hemispheres from 25 adult cadavers in which the arteries and veins had been perfused with red and blue silicone, respectively. Special consideration was given to the size and location of drainage of the vein of Galen and its tributaries. Conclusions. When a surgeon approaches the pineal region, several veins may hamper the access route. From posterior to anterior, these include the following: the superior vermian and the precentral or superior cerebellar veins, which drain into the posteroinferior aspect of the vein of Galen; and the tectal and pineal veins, which drain into its anterosuperior aspect. The internal occipital vein is the main vessel draining into the lateral aspect of the vein of Galen. It may be joined by the posterior pericallosal vein, and in that case has an extensive territory. To avoid intraoperative venous infarction, it is important to use angiography to determine the venous organization before surgery and to estimate the permeability and size of the branches of the deep venous system.

scholarly journals Innervation of the Cerebral Veins as Compared with the Cerebral Arteries: A Histochemical and Electron Microscopic Study

1983 ◽  
Vol 3 (1) ◽  
pp. 127-132 ◽  
Author(s):  
Kazuo Nakakita ◽  
Harumichi Imai ◽  
Ichiro Kamei ◽  
Yutaka Naka ◽  
Kunio Nakai ◽  
...  
Keyword(s):  
Cerebral Arteries ◽  
Nerve Fibers ◽  
Venous System ◽  
Arterial System ◽  
Dural Sinus ◽  
Cerebral Vein ◽  
Cerebral Veins ◽  
Electron Microscopic ◽  
Internal Cerebral Vein ◽  
Green Fluorescent

The distribution of nerve fibers in the cerebral veins was studied by catecholamine fluorescence simultaneously with acetylcholinesterase (AChE) histochemistry. A comparison of nerve fibers in the cerebral arteries was made, The ultrastructure of terminal boutons in the veins fixed with potassium permanganate was also studied, In the adventitia of the cerebral artery, green fluorescent aminergic fibers and brownish AChE-reactive (probably cholinergic) fibers were observed. In contrast, the cerebral venous system showed no AChE-positive fibers. Catecholamine fluorescent varicose fibers were detected in the dural sinus, the internal cerebral vein, and the superficial vein of Labbé. The highest density of aminergic fibers was found in the dural sinus and the second highest in the internal cerebral vein. Most of the terminal boutons in the adventitia of the cerebral veins were found adjacent to a muscle-like cell and showed only cored vesicles under electron microscopy. Results of our study suggest that the cerebral venous system has a neurogenic innervation, mainly from aminergic fibers, which is different from the neurogenic supply to the cerebral arterial system.

Vascular smooth muscle cell stress as a determinant of cerebral artery myogenic tone

2002 ◽  
Vol 283 (6) ◽  
pp. H2210-H2216 ◽  
Author(s):  
Johan Fredrik Brekke ◽  
Natalia I. Gokina ◽  
George Osol
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cell ◽  
Muscle Cell ◽  
Vascular Smooth Muscle Cell ◽  
Wall Stress ◽  
Cytosolic Calcium ◽  
Cell Stress ◽  
Myogenic Tone ◽  
Vessel Size

Although the level of myogenic tone (MT) varies considerably from vessel to vessel, the regulatory mechanisms through which the actual diameter set point is determined are not known. We hypothesized that a unifying principle may be the equalization of active force at the contractile filament level, which would be reflected in a normalization of wall stress or, more specifically, media stress. Branched segments of rat cerebral arteries ranging from <50 μm to >200 μm in diameter were cannulated and held at 60 mmHg with the objectives of: 1) evaluating the relationship between arterial diameter and the extent of myogenic tone, 2) determining whether differences in MT correlate with changes in cytosolic calcium ([Ca2+]i), and 3) testing the hypothesis that a normalization of wall or media stress occurs during the process of tone development. The level of MT increased significantly as vessel size decreased. At 60 mmHg, vascular smooth muscle [Ca2+]i concentrations were similar in all vessels studied (averaging 230 ± 9.2 nM) and not correlated with vessel size or the extent of tone. Wall tension increased with increasing arterial size, but wall stress and media stress were similar in large versus small arteries. Media stress, in particular, was quite uniform in all vessels studied. Both morphological and calcium data support the concept of equalization of media stress (and, hence, vascular smooth muscle cell stress and force) as an underlying mechanism in determining the level of tone present in any particular vessel. The equalization of active (vascular smooth muscle cell) stress may thus explain differences in MT observed in the different-sized vessels constituting the arterial network and provide a link between arterial structure and function, in both short- and long-term (hypertension) pressure adaptation.

Embryological basis of some aspects of cerebral vascular fistulas and malformations

1996 ◽  
Vol 85 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Sean Mullan ◽  
Saeid Mojtahedi ◽  
Douglas L. Johnson ◽  
R. Loch Macdonald
Keyword(s):  
Cavernous Sinus ◽  
Cerebral Vein ◽  
Cerebral Veins ◽  
Vein Of Galen Aneurysm ◽  
Content Type ◽  
Clinical Observations ◽  
Internal Cerebral Veins ◽  
Superior Petrosal Sinus ◽  
Frequent Absence ◽  
Frequent Failure

✓ The literature on the formation of cerebral veins is reviewed to obtain a better understanding of some cerebrovascular anomalies. Clinical observations such as the entry of the superior ophthalmic vein into the cavernous sinus through the inferior rather than the superior orbital fissure, the relative infrequency of middle cerebral vein backflow in the presence of an extensive cavernous fistula, and the relative infrequency of hemorrhage in relation to the inferior petrosal fistula all relate to the persistence of an older venous pathway. The frequent occurrence of hemorrhage in association with the superior petrosal sinus fistula and the frequent failure of the superior petrosal sinus to connect to the cavernous sinus similarly have an embryological explanation. The frequent association of the vein of Galen aneurysm and an absent or deformed straight sinus probably relates to the time at which the paired internal cerebral veins fuse into one channel. It is speculated that the origins of cerebral venous malformations (CVMs) and arteriovenous malformations (AVMs) probably relate to sequential formation and absorption of surface veins, which occur in human embryonic development mainly in the 40- to 80-mm length interval, although persistent AVM growth is possible even after birth. The frequent absence or anomaly of the middle cerebral vein and its failure to communicate with the cavernous sinus in the presence of both CVMs and AVMs are linked to the late development of that vein and to its even later connection to the cavernous sinus.

Coronary artery myogenic response in a genetic model of hypertrophic cardiomyopathy

2002 ◽  
Vol 283 (6) ◽  
pp. H2244-H2249 ◽  
Author(s):  
Henrik H. Petersen ◽  
Jonathan Choy ◽  
Brian Stauffer ◽  
Farzad Moien-Afshari ◽  
Christian Aalkjaer ◽  
...  
Keyword(s):  
Transgenic Mouse ◽  
Genetic Model ◽  
Morphological Characteristics ◽  
Myogenic Tone ◽  
Chain Gene ◽  
Myogenic Response ◽  
Cardiac Phenotype ◽  
First Time ◽  
Pressure Myograph ◽  
Intravascular Pressure

Hypertrophic cardiac myopathy (HCM) is the leading cause of mortality in young athletes. Abnormalities in small intramural coronary arteries have been observed at autopsy in such subjects. The walls of these intramural vessels, especially in the ventricular septum, are thickened, and the lumen frequently appears narrowed. Whether these morphological characteristics have functional correlates is unknown. We studied coronary myogenic tone in a transgenic mouse model of HCM that has mutations in the cardiac α-myosin heavy chain gene. This transgenic mouse has a cardiac phenotype that resembles that occurring in humans. We examined the possible vascular contributions to the pathology of HCM. Septal arteries from 3- and 11-mo-old wild-type (WT) and transgenic (TG) mice were studied on a pressure myograph. The myogenic response to increased intravascular pressure in older animals was significantly reduced [maximal constriction: 32 ± 4% (TG) and 46 ± 4% (WT), P < 0.05]. After inhibition of endothelin receptors with bosentan, both WT and TG mice had similar increases in myogenic constriction. The sensitivity to exogenous endothelin was significantly reduced in TG mice, suggesting that the reduced myogenic constriction in HCM was due to reduced receptor sensitivity. In conclusion, we show for the first time that 1) myogenic tone in the coronary septal artery of the mouse is regulated by a basal release of endothelin, and 2) pressure-induced myogenic activation is attenuated in HCM, possibly consequent to a reduction in endothelin responsiveness. The associated reduction in coronary vasodilatory reserve may increase susceptibility to ischemia and arrhythmias.

scholarly journals NO can suppress myogenic tone in rat middle cerebral arteries by activating BK Ca

2006 ◽  
Vol 20 (5) ◽  
Author(s):  
Alister James McNeish ◽  
Kim Dora ◽  
Chris Garland
Keyword(s):  
Cerebral Arteries ◽  
Myogenic Tone ◽  
Middle Cerebral Arteries

scholarly journals Most small cerebral cortical veins demonstrate significant flow pulsatility: a human phase contrast MRI study at 7T

2020 ◽  
Author(s):  
Ian D Driver ◽  
Maarika Traat ◽  
Fabrizio Fasano ◽  
Richard G Wise
Keyword(s):  
Phase Contrast ◽  
Cerebral Arteries ◽  
Normal Pressure ◽  
7 Tesla ◽  
Cerebral Veins ◽  
Phase Contrast Mri ◽  
Venous Flow ◽  
Sagittal Sinus ◽  
Automated Method ◽  
Flow Pulsatility

AbstractPhase contrast MRI has been used to investigate flow pulsatility in cerebral arteries, larger cerebral veins and the cerebrospinal fluid. Such measurements of intracranial pulsatility and compliance are beginning to inform understanding of the pathophysiology of conditions including normal pressure hydrocephalus, multiple sclerosis and dementias. We demonstrate the presence of flow pulsatility in small cerebral cortical veins, for the first time using phase contrast MRI at 7 Tesla, with the aim of improving our understanding of the haemodynamics of this little-studied vascular compartment. An automated method for establishing where venous flow is pulsatile is introduced, revealing significant pulsatility in 116 out of 146 veins, across 8 healthy participants, assessed in parietal and frontal regions. Distributions of pulsatility index and pulse waveform delay were characterized, indicating a small, but statistically significant (p<0.05), delay of 59±41 ms in cortical veins with respect to the superior sagittal sinus, but no differences between veins draining different arterial supply territories. Measurements of pulsatility in smaller cortical veins, a hitherto unstudied compartment closer to the capillary bed, could lead to a better understanding of intracranial compliance and cerebrovascular (patho)physiology.

Sex-specific differences in cerebral arterial myogenic tone in hypertensive and normotensive rats

2006 ◽  
Vol 290 (3) ◽  
pp. H1081-H1089 ◽  
Author(s):  
Jamila Ibrahim ◽  
Ann McGee ◽  
Delyth Graham ◽  
John C. McGrath ◽  
Anna F. Dominiczak
Keyword(s):  
Blood Flow ◽  
Cerebral Arteries ◽  
Systemic Blood Pressure ◽  
Limiting Factors ◽  
Myogenic Tone ◽  
Spontaneously Hypertensive ◽  
Cerebrovascular Events ◽  
Middle Cerebral Arteries ◽  
Wistar Kyoto ◽  
Strain Dependent

Cerebral blood flow (CBF) is maintained constant despite changes in systemic blood pressure (BP) through multiple mechanisms of autoregulation such as vascular myogenic reactivity. Our aim was to determine myogenic characteristics of cannulated middle cerebral arteries (MCA) in male and female stroke-prone spontaneously hypertensive rats (SHRSP) and Wistar-Kyoto rats (WKY) at 12 wk of age under pressurised no-flow conditions. MCA pressure-diameter relationships (20–200 mmHg) were constructed in active (with calcium) and passive (without calcium) conditions, and myogenic and mechanical properties were determined. Myogenic reactivity in WKY ( P < 0.05) and SHRSP ( P < 0.05) males was impaired compared with their female counterparts. Comparison of SHRSP with WKY in males revealed similar myogenic reactivity, but in females SHRSP exhibited augmented myogenic reactivity ( P < 0.05). In both sexes, myogenic tone yielded at lower pressure in SHRSP compared with WKY vessels (120–140 vs. 140–180 mmHg). Stress-strain relationships and elastic moduli in WKY rats showed that vessels were stiffer in females than in males. Conversely, in SHRSP, male vessels were stiffer than female vessels. Comparison of strains in males indicated that stiffness was increased in SHRSP compared with WKY vessels, whereas the converse was observed in females. These findings demonstrate that MCA myogenic and distensibility characteristics exhibit significant sex- and strain-dependent differences. Inappropriate myogenic adaptation and augmented vascular stiffness, particularly in male SHRSP, are potential limiting factors in blood flow autoregulation and may increase the predisposition for stroke-related cerebrovascular events.

Hemodynamics and metabolism of the in vivo vascularly isolated canine pancreas.

1979 ◽  
Vol 236 (6) ◽  
pp. E626
Author(s):  
R J Alteveer ◽  
M J Jaffe ◽  
J Van Dam
Keyword(s):  
Blood Flow ◽  
Glucose Uptake ◽  
Venous Blood ◽  
Fatty Acid Uptake ◽  
Acid Uptake ◽  
Anesthetized Dogs ◽  
Metabolic Variables ◽  
The Stability ◽  
First Time

Surgical procedures are detailed that have yielded for the first time an in vivo vascularly isolated, autoperfused preparation of the entire pancreas in anesthetized dogs. Previous studies had isolated only part of the pancreas or had resorted to blood-flow techniques not requiring pooled pancreatic venous blood, necessary for metabolic studies of the organ. Pancreatic blood flow (48 ml/min), O2 uptake (180 mumol/min), glucose uptake (51.0 mumol/min), lactate output (6.6 mumol/min), net free fatty acid uptake (2.23 mumol/min), all per 100 g tissue, and various other measured and calculated hemodynamic and metabolic variables were determined on the preparation during control conditions. The stability of the preparation was verified by serial determinations of these parameters and of blood alpha-amylase and beta-glucuronidase levels from 1 to 2.5 h postsurgery. Metabolic rate and glucose uptake were both found to be much higher than in intestinal tissues and approached values characteristic of liver tissue.

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