The ELANA technique: high flow revascularization of the brain

2005 ◽  
pp. 143-148 ◽  
Author(s):  
H. J. Streefkerk ◽  
J. P. Bremmer ◽  
C. A. Tulleken
Keyword(s):  
High Flow ◽  
The Brain

scholarly journals Distribution and stability of antisense phosphorothioate oligonucleotides in rodent brain following direct intraparenchymal controlled-rate infusion

1997 ◽  
Vol 3 (5) ◽  
pp. E6 ◽  
Author(s):  
William C. Broaddus ◽  
Sujit S. Prabhu ◽  
George T. Gillies ◽  
Jeffrey Neal ◽  
William S. Conrad ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Structural Changes ◽  
Tissue Concentration ◽  
Volume Of Distribution ◽  
Brain Parenchyma ◽  
Average Concentration ◽  
High Flow ◽  
Fischer 344 ◽  
High Concentrations ◽  
The Brain

High-flow microinfusion is a novel technique for delivery of compounds directly into the brain parenchyma, bypassing the blood-brain barrier. The feasibility of this technique has been demonstrated with low-molecular-weight compounds, macromolecular dyes, and proteins. Delivery of antisense oligonucleotides into the brain parenchyma represents an additional potential application of this technique not previously described. In this report, the authors examined the distribution and disposition of phosphorothioate oligodeoxynucleotide (PS-ODN) infused for this reason. An 18-mer 35S-PS-ODN (molecular weight approximately 6000) was infused over 1 hour into the caudate putamen of Fischer 344 rats. At 1, 6, 12, 24, and 48 hours after beginning the infusion, the brains were extracted and analyzed using quantitative autoradiographic techniques. Cerebrospinal fluid (CSF) was also aspirated from the cisterna magna and analyzed for radioactivity and stability of the 35S-PS-ODN. At 1 hour, the infused ODN was uniformly distributed in brain tissue, with a maximum average concentration of 4806.5 ± 210.5 nCi/g. This represents a tissue concentration of 19.2 ± 0.84 μM. Extensive spread into surrounding parenchyma was observed over the ensuing 47 hours. The 35S-PS-ODN radioactivity peaked in the CSF at the end of the 1-hour infusion, containing 10% (50 ± 20 nCi) of the infused radioactivity. Activity then decayed exponentially over 11 hours, stabilizing at a lower CSF content of 0.2% (1 ± 0.1 nCi). The volume of distribution (Vd) was 105 ± 7.9 mm3 at 1 hour, representing a ratio of Vd/Vi (volume of infusion) of 5.2. The Vd increased to 443.4 ± 62.3 mm3 at the end of 48 hours, whereas the average minimum tissue concentration decreased from 15.2 to 3.2 μM. Undegraded 18-mer was seen throughout the 48-hour period using 20% polyacrylamide/7M urea gel electrophoresis. The animals tolerated the infusion without evidence of toxicity, and minimal structural changes in tissue were observed on histological examination. Thus, PS-ODN can be safely delivered in high concentrations to wide areas of the rat brain by using high-flow microinfusion, and the concentrations remain stable even after 48 hours in situ.

The Effect of Altered Cerebral Blood Flow on the Cerebral Kinetics of Thiopental and Propofol in Sheep

2000 ◽  
Vol 93 (4) ◽  
pp. 1085-1094 ◽  
Author(s):  
Richard N. Upton ◽  
Guy L. Ludbrook ◽  
Cliff Grant ◽  
David J. Doolette
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Random Order ◽  
High Flow ◽  
Low Flow ◽  
Flow State ◽  
Concentration Difference ◽  
Blood Flows ◽  
Kinetics Of ◽  
The Brain

Background Thiopental and propofol are highly lipid-soluble, and their entry into the brain often is assumed to be limited by cerebral blood flow rather than by a diffusion barrier. However, there is little direct experimental evidence for this assumption. Methods The cerebral kinetics of thiopental and propofol were examined over a range of cerebral blood flows using five and six chronically instrumented sheep, respectively. Using anesthesia (2.0% halothane), three steady state levels of cerebral blood flow (low, medium, and high) were achieved in random order by altering arterial carbon dioxide tension. For each flow state, 250 mg thiopental or 100 mg propofol was infused intravenously over 2 min. To quantify cerebral kinetics, arterial and sagittal sinus blood was sampled rapidly for 20 min from the start of the infusion, and 1.5 h was allowed between consecutive infusions. Various models of cerebral kinetics were examined for their ability to account for the data. Results The mean baseline cerebral blood flows for the "high" flow state were over threefold greater than those for the low. For the high-flow state the normalized arteriovenous concentration difference across the brain was smaller than for the low-flow state, for both drugs. The data were better described by a model with partial membrane limitation than those with only flow limitation or dispersion. Conclusions The cerebral kinetics of thiopental and propofol after bolus injection were dependent on cerebral blood flow, despite partial diffusion limitation. Higher flows produce higher peak cerebral concentrations.

The cerebrofacial metameric syndromes: An embryological review and proposal of a novel classification scheme

2021 ◽  
pp. 159101992110449
Author(s):  
Anthony S. Larson ◽  
Waleed Brinjikji ◽  
Timo Krings ◽  
Julie B. Guerin
Keyword(s):  
Cell Migration ◽  
Classification System ◽  
Classification Scheme ◽  
Vascular Malformations ◽  
High Flow ◽  
Low Flow ◽  
Pharyngeal Arches ◽  
Detailed Classification ◽  
Vascular Syndromes ◽  
The Brain

The cerebrofacial metameric syndromes are a group of congenital syndromes that result in vascular malformations throughout specific anatomical distributions of the brain, cranium and face. Multiple reports of patients with high-flow or low-flow vascular malformations following a metameric distribution have supported this idea. There has been much advancement in understanding of segmental organization and cell migration since the concept of metameric vascular syndromes was first proposed. We aim to give an updated review of these embryological considerations and then propose a more detailed classification system for these syndromes, predominately incorporating the contribution of neural crest cells and somitomeres to the pharyngeal arches.

Balloon-assisted Onyx embolization of cerebral single-channel pial arteriovenous fistulas

2011 ◽  
Vol 7 (6) ◽  
pp. 637-642 ◽  
Author(s):  
C. Benjamin Newman ◽  
Yin C. Hu ◽  
Cameron G. McDougall ◽  
Felipe C. Albuquerque
Keyword(s):  
Treatment Strategy ◽  
Pediatric Patients ◽  
Single Channel ◽  
Vascular Malformations ◽  
High Flow ◽  
Flow Dynamics ◽  
Arteriovenous Fistulas ◽  
Male Patients ◽  
The Brain

Object Pial arteriovenous fistulas (AVFs) of the brain are rare vascular malformations associated with significant risks of hemorrhage and neurological deficit. Depending on their location and high-flow dynamics, these lesions can present treatment challenges for both endovascular and open cerebrovascular surgeons. The authors describe a novel endovascular treatment strategy that was used successfully to treat 2 pediatric patients with a pial AVF, and they discuss the technical nuances specific to their treatment strategy. Methods A single-channel high-flow pial AVF was diagnosed in 2 male patients (6 and 17 years of age). Both patients were treated with endovascular flow arrest using a highly conformable balloon followed by Onyx infusion for definitive closure of the fistula. Results Neither patient suffered a complication as a result of the procedure. At the 6-month follow-up in both cases, the simple discontinuation of blood flow had resulted in durable obliteration of the fistula and stable or improved neurological function. Conclusions Onyx can be delivered successfully into high-flow lesions after flow arrest to allow a minimally invasive and durable treatment for pial AVFs.

scholarly journals Aortic stiffness, pressure and flow pulsatility, and target organ damage

2018 ◽  
Vol 125 (6) ◽  
pp. 1871-1880 ◽  
Author(s):  
Gary F. Mitchell
Keyword(s):  
Kidney Disease ◽  
Aortic Stiffness ◽  
Target Organ Damage ◽  
Global Longitudinal Strain ◽  
Organ Damage ◽  
High Flow ◽  
Small Vessels ◽  
Flow Pulsatility ◽  
Pulsatile Load ◽  
The Brain

Measures of aortic stiffness and pressure and flow pulsatility have emerged as correlates of and potential contributors to cardiovascular disease, dementia, and kidney disease. Higher aortic stiffness and greater pressure and flow pulsatility are associated with excessive pulsatile load on the heart, which increases mass and reduces global longitudinal strain of the left ventricle. Excessive stiffness and pulsatility are also associated with microvascular lesions in high-flow organs, such as the brain and kidney, suggesting that small vessels in these organs are damaged by pulsatility. This brief review will summarize evidence relating aortic stiffness to cardiovascular, brain, and kidney disease.

scholarly journals Pregnancy increases myometrial artery myogenic tone via NOS- or COX-independent mechanisms

2012 ◽  
Vol 303 (4) ◽  
pp. R368-R375 ◽  
Author(s):  
Delrae M. Eckman ◽  
Ridhima Gupta ◽  
Charles R. Rosenfeld ◽  
Timothy M. Morgan ◽  
Shelton M. Charles ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Skeletal Muscle ◽  
Pregnant Women ◽  
High Flow ◽  
Myogenic Tone ◽  
Internal Diameter ◽  
Pregnant Uterus ◽  
Voltage Dependent ◽  
Oxide Synthase ◽  
The Brain

Myogenic tone (MT) is a primary modulator of blood flow in the resistance vasculature of the brain, kidney, skeletal muscle, and perhaps in other high-flow organs such as the pregnant uterus. MT is known to be regulated by endothelium-derived factors, including products of the nitric oxide synthase (NOS) and/or the cyclooxygenase (COX) pathways. We asked whether pregnancy influenced MT in myometrial arteries (MA), and if so, whether such an effect could be attributed to alterations in NOS and/or COX. MA (200–300 μm internal diameter, 2–3 mm length) were isolated from 10 nonpregnant and 12 pregnant women undergoing elective hysterectomy or cesarean section, respectively. In the absence of NOS and/or COX inhibition, pregnancy was associated with increased MT in endothelium-intact MA compared with MA from nonpregnant women ( P < 0.01). The increase in MT was not due to increased Ca2+ entry via voltage-dependent channels since both groups of MA exhibited similar levels of constriction when exposed to 50 mM KCl. NOS inhibition ( Nω-nitro-l-arginine methyl ester, l-NAME) or combined NOS/COX inhibition (l-NAME/indomethacin) increased MT in MA from pregnant women ( P = 0.001 and P = 0.042, respectively) but was without effect in arteries from nonpregnant women. Indomethacin alone was without effect on MT in MA from either nonpregnant or pregnant women. We concluded that MT increases in MA during human pregnancy and that this effect was partially opposed by enhanced NOS activity.

scholarly journals De novo intracranial arteriovenous malformation development after endovascular treatment for a pial arteriovenous fistula in capillary malformation-arteriovenous malformation syndrome

2020 ◽  
pp. 159101992094051
Author(s):  
Bikei Ryu ◽  
Shinsuke Sato ◽  
Tatsuki Mochizuki ◽  
Tatsuya Inoue ◽  
Yoshikazu Okada ◽  
...  
Keyword(s):  
Arteriovenous Malformation ◽  
Arteriovenous Fistula ◽  
De Novo ◽  
High Flow ◽  
Intracranial Arteriovenous Malformation ◽  
Capillary Malformation ◽  
Systemic Disorder ◽  
Pial Arteriovenous Fistula ◽  
The Brain

Capillary malformation-arteriovenous malformation (CM-AVM) syndrome is a newly described entity characterized by autosomal dominantly inherited multifocal capillary malformations caused by RASA1 mutations (CM-AVM1) or EPHB4 mutations (CM-AVM2). Concurrent high-flow vascular anomalies in the brain are often present in the form of intracranial AVM or arteriovenous fistula (AVF). These high-flow lesions are often identified at or soon after birth because of the characteristic unique capillary malformations or a systemic disorder due to a high-flow shunt, such as respiratory distress or heart failure. However, de novo intracranial AVMs have not been reported in patients with CM-AVM syndrome. Herein, we report the case of a six-year-old boy with CM-AVM1 who had been treated for an intracranial pial arteriovenous fistula approximately five years previously, in whom a de novo intracranial AVM was identified on a follow-up angiographic study. To the best of our knowledge, this report is the first to document a de novo intracranial AVM in a patient with CM-AVM. We recommend careful neuroimaging follow-up even if initial neuroimaging screening is negative because of the risk of de novo AVM development.

scholarly journals Wyburn-Mason or Bonnet-Dechaume-Blanc as Cerebrofacial Arteriovenous Metameric Syndromes (CAMS)

2001 ◽  
Vol 7 (1) ◽  
pp. 5-17 ◽  
Author(s):  
J.J. Bhattacharya ◽  
C.B. Luo ◽  
D.C. Suh ◽  
H. Alvarez ◽  
G. Rodesch ◽  
...  
Keyword(s):  
Developmental Biology ◽  
Diagnostic Criteria ◽  
Arteriovenous Malformations ◽  
Phenotypic Expression ◽  
High Flow ◽  
Review Of The Literature ◽  
Life Threatening ◽  
Underlying Disorder ◽  
The Brain ◽  
Rational Classification

The diagnosis of Bonnet-Dechaume-Blanc or Wyburn-Mason syndrome encompasses a spectrum of phenotypic expression. Features of the syndrome as originally described, and common to all, include arteriovenous malformations of the brain and orbit (with retinal and/or retrobulbar lesions). A portion of these patients manifest the complete expression of the disease with additional high-flow arteriovenous malformations of the maxillofacial or mandibular regions. These present the distinct and additional risks of life-threatening epistaxis or gingival haemorrhage. We suggest new diagnostic criteria for the syndrome. Applying insights from modern developmental biology to our series of 15 patients (the largest to date), together with a review of the literature, we have recognised metameric patterns of involvement in what we believe to be a disease of the neural crest or adjacent cephalic mesoderm. This allows us to propose a new rational classification reflecting the putative, underlying disorder and to suggest a new name: Cerebrofacial Arteriovenous Metameric Syndrome (CAMS).

The Nd:YAG laser in neurosurgery

1984 ◽  
Vol 60 (3) ◽  
pp. 540-547 ◽  
Author(s):  
Robert E. Wharen ◽  
Robert E. Anderson ◽  
Thoralf M. Sundt
Keyword(s):  
Nd:Yag Laser ◽  
Arteriovenous Malformations ◽  
Laser Light ◽  
High Flow ◽  
Content Type ◽  
Light Delivery ◽  
Light Filters ◽  
Protective Eyewear ◽  
Thin Walled ◽  
The Brain

✓ The Nd:YAG laser has been used safely to aid in the resection of 10 cases of parenchymal arteriovenous malformations (AVM's). The laser was, found helpful for: 1) defining the plane between the AVM and the brain; 2) coagulating any dural component of the AVM; and 3) achieving hemostasis of the bed following resection of the lesion. However, its overall benefit in the resection of AVM's remains to be determined, as it could not arrest active high-flow bleeding from the thin-walled vessels feeding the deep portion of the AVM. This was attributed to the inherent characteristics of these vessels, since the instrument has been effective in non-AVM arteries of similar dimensions containing contractile elements in the vessel walls. Future refinements in focusing instrumentation and operative technique should enhance its capabilities and usefulness. When used within the recommended power range, the Nd:YAG laser is safe and its penetration predictable. The fiberoptic cable light delivery system allows excellent mobility of the handpiece, but the protective eyewear laser-light filters reduce the available light to the surgeon. The instrument appears promising but more work is required.

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