Extracranial Vessels Research Articles

Development of cerebrospinal fluid absorption sites in the pig and rat: connections between the subarachnoid space and lymphatic vessels in the olfactory turbinates

The textbook view that cerebrospinal fluid (CSF) absorption occurs mainly through the arachnoid granulations and villi is being challenged by quantitative and qualitative studies that support a major role for the lymphatic circulation in CSF transport. There are many potential sites at which lymphatics may gain access to CSF but the primary pathway involves the movement of CSF through the cribriform plate foramina in association with the olfactory nerves. Lymphatics encircle the nerve trunks on the extracranial surface of the cribriform plate and absorb CSF. However, the time during development in which the CSF compartment and extracranial lymphatic vessels connect anatomically is unclear. In this report, CSF-lymphatic connections were investigated using the silastic material Microfil and a soluble Evan's blue-protein complex in two species; one in which significant CSF synthesis by the choroid plexus begins before birth (pigs) and one in which CSF secretion is markedly up regulated within the first weeks after birth (rats). We examined a total of 46 pig fetuses at embryonic (E) day E80-81, E92, E101, E110 (birth at 114 days). In rats, we investigated a total of 115 animals at E21 (birth at 21 days), postnatal (P) day P1-P9, P12, P13, P15, P22, and adults. In pigs, CSF-lymphatic connections were observed in the prenatal period as early as E92. Before this time (E80-81 fetuses) CSF-lymphatic connections did not appear to exist. In rats, these associations were not obvious until about a week after birth. These data suggest that the ability of extracranial lymphatic vessels to absorb CSF develops around the time that significant volumes of CSF are being produced by the choroid plexus and further support an important role for lymphatic vessels in CSF transport.

Multimodal Use of Computed Tomography in Early Acute Stroke, Part 2

Computed tomography (CT) scan remains the most widely technique in the cerebrovascular emergency, as it is largely available, minimally invasive, fast, cheap and reliable. Noncontrast enhanced CT (NeCT) imaging can show early signs of infarction in ischemic stroke; however, it could not show if the ischemic tissue is irreversibly damaged. CT perfusion (CTP) imaging has been shown to predict stroke location and size and can provide information about ischemic cerebral parenchyma not definitively compromised. CT angiography (CTA) could highlight stenosis or occlusion both in intracranial and extracranial vessels. By combining NeCT, CTP, and CTA the entire cerebrovascular axis can be imaged during acute stroke. Currently, the term “multimodal CT” indicates the combined use of these three techniques in order to obtain a complete picture of the extension of ischemic damage in acute stroke patients.

Book review

The title given to the text, Manual of Peripheral Vascular Intervention, is somewhat of a misnomer. This text should be referred to instead as a “Manual of Noncoronary Interventions” to indicate that it attempts to include all other vascular beds, including the intracranial circulation as well as the peripheral vascular bed. The authors have taken on an immense task of putting together a well-researched and readable how-to guide for most current arterial interventions. The result of their efforts is a text that will likely find a forward site in the library of most practicing interventionalists. The first chapter deals with training and credentialing for peripheral vascular interventions, including alternative pathways, which are well discussed and politically correct. There is mention of the fact that competency in interventions of the extracranial cerebral vessels is considered a “unique category”; however, there is no specific mention of the number of cases that would be considered necessary to achieve this competence. There are also chapters included on intracranial interventions that correctly stress how unforgiving this territory can be; however, no discussion is made as to the training requirements for this very delicate field of work other than mention of the “cerebrovascular endovascular specialist.” This aside, the text is appealing to all of the different physician groups managing patients with vascular disease because of the vast experience that each selected author brings to his or her subject. Each chapter is broken down into basic anatomy and patient selection and indications, followed by technique and published outcomes in arteries (and veins) from head to toe. Whether the reader chooses to read the book in its entirety or by individual chapter according to clinical need, this book meets its goal as a how-to manual, discussing catheter, wire, and balloon choices, as well as how to select optimal access sites. The images and graphics are useful, especially the pictorial guides of catheter types used for vessel selection. Many of the related topics, such as carotid interventions and intracranial interventions, have shared authors so that there is no repetition of material among these well-written chapters. The discussion of peripheral arterial thrombolysis is the most complete, yet concise, review of data available on thrombolytic therapy available and is presented without product bias. Other excellent chapters follow this on mechanical thrombectomy devices; aortoiliac, infrainguinal, and infrapopliteal interventions; and renal and mesenteric interventions. Discussions of endovascular treatment of aneurysmal disease of the aorta and elsewhere are also included. Overall, the authors should be commended on bringing together so many experts to compile this thorough manual on noncoronary vascular interventions. This text can serve both as a how-to manual for those just beginning their career in the periphery and as a terrific review of outcomes of endovascular therapy for those with different levels of experience. It will be useful for residents and fellows in all vascular specialties, as well as for experienced practitioners expanding their vascular practice.

A historical perspective of tissue doppler: When the starlight illuminates themyocardial function

In 1842, an Austrian professor of mathematics and practical geometry, Christian Doppler, presented results of his investigations in the field of astronomy, without any clue that they would become important principles of modern ultrasound diagnostics. Almost a century later, at the University of Osaka, Japan, S. Satomura first applied these principles to measure the blood flow velocities in peripheral and extracranial brain-supplying vessels. The father of tissue Doppler imaging is Karl Isaaz, a French scientist, who was the first to realize the importance of clinical and diagnostic potentials of tissue Doppler imaging. Today, this noninvasive echocardiographic method is widely used in evaluation of myocardial function, especially in diagnosing of diastolic heart failure and early diagnosis of coronary artery disease, but also in diffrential diagnosis of restrictive cardiomyopathy and constrictive pericarditis and aberrant myocardial conduction. It is also an antecedent of "stain rate", a new sensitive method for diagnosing myocardial diseases.

HEMODYNAMIC EFFECTS OF CARVEDILOL IN PATIENTS WITH ARTERIAL HYPERTENSION

Aim. To evaluate the influence of carvedilol (Talliton, Egis, Hungary) on daily profile of blood pressure (BP), anatomical and functional conditions of left ventricle (LV) and cerebral circulation in patients with arterial hypertension (AH), stage II-III. Material and methods. 30 patients (10 men, 20 women, average age 51,9±7,9 y.o.) with AH II-III stage ( RSSC,2004) and with initially affected daily profile of BP, cerebral circulation, anatomical and functional disorders of LV took carvedilol 25-75 mg/d during 6 months. Hemodynamics was estimated by ambulatory BP monitoring, Doppler Echocardiography, and ultrasound Dopplerography of extra cranial vessels. Results. A normalizing effect of carvedilol on abnormal daily profile of BP and cerebral circulation was determined. The treatment resulted in the regress of LV hypertrophy with predominant reduction of interventricular septum thickness and also the transformation of concentrical LV hypertrophy in excentrical one. Conclusion. Long-term therapy with carvedilol in patients with AH II-III stage provides a stable BP control and cardioprotective effect, improves cerebral circulation.

Craniocervical Arterial Dissection in Children: Clinical and Radiographic Presentation and Outcome

Craniocervical arterial dissection is a recognized cause of arterial ischemic stroke in children. Whether children with craniocervical arterial dissection have dissection characteristics different from those of adults is unclear. A retrospective review of children, 1 month to 18 years of age, with dissection from two Canadian pediatric ischemic stroke registry centers was conducted. From 213 patients with arterial ischemic stroke, 16 (7.5%) were identified with dissection, 37.5% had warning symptoms, and 50% had a history of head or neck trauma. The clinical presentation included headache (44%), altered consciousness (25%), seizures (12.5%), and focal deficits (87.5%). Dissection involved extracranial vessels in 75% and anterior circulation in 56%. Follow-up included complete recovery in 43%, mild to moderate deficits in 44%, and severe deficits in 13%. Fourteen (87.5%) children received antithrombotic treatment. Follow-up angiography showed resolution of abnormalities in 60% of vessels. Total occlusion had the worst outcome for recanalization. In conclusion, the etiology of arterial dissection in the majority of children appears to be either trauma or idiopathic. Long-term angiography shows variable outcomes, depending on the initial findings. The relationship of angiographic outcomes with recurrent strokes requires further study in pediatric dissection. (J Child Neurol 2006;21:8-16).

Investigation and management of subclavian steal syndrome.

Patients with subclavian steal syndrome present with symptoms of vertebrobasilar ischaemia. Although angiography has traditionally been used to confirm the diagnosis of subclavian steal and plan reconstructive surgery in symptomatic patients, duplex ultrasonography now offers rapid diagnosis and also permits examination of the other extracranial vessels. The treatment of subclavian steal syndrome is surgical. Extra-anatomic bypass procedures are used to increase inflow to the subclavian artery, abolishing the steal phenomenon. Carotid-subclavian bypass or transposition and subclavian-subclavian or axilloaxillary bypass are the procedures of choice; selection is governed by the presence of coexistent carotid artery disease. Percutaneous transluminal balloon angioplasty of the subclavian artery is an alternative treatment, although the long-term patency rate is inferior to that of extra-anatomic bypass.

Carotid artery bruit: association with internal carotid stenosis and intraluminal turbulence.

One hundred and ninety-five consecutive referrals to the vascular laboratory for carotid artery investigation have been studied. Carotid bruits were assessed by the referring clinician and documented. All patients underwent bilateral imaging and spectrum analysis of the extra-cranial carotid vessels using a pulsed Doppler ultrasound technique. Eighty-two were further assessed by X-ray contrast angiography. Of 390 internal carotids examined by ultrasound, 65 exhibited intraluminal turbulence of which 49 (75 per cent) had a bruit. In 62 (56 per cent) of 111 internal carotids in the series which were said to have a bruit on clinical examination, no turbulence was found; in 15 instances the external carotid vessel was shown as the true source of turbulence and in the remainder the bruits may have been transmitted from the heart. One hundred and fifty-six vessels were assessed by X-ray and 55 shown to have significant stenosis; 38 (69 per cent) of these exhibited a bruit. Bruit was often absent at high degrees of stenosis and in occluded vessels. Although a carotid bruit is often a marker of internal carotid intraluminal turbulence and stenosis, this is by no means always so. Cervical bruit may also be due to a diseased external carotid or to sounds transmitted from a more proximal source. Conversely, absence of bruit is a feature not only of normal vessels but of many arteries which are stenosed (especially if this is of high degree) or occluded.

Surgical management of acute carotid thrombosis after carotid stenting: A report of three cases

We report three cases of symptomatic acute carotid thrombosis occurring after carotid artery stenting (CAS). CASE 1: A patient presented with crescendo transient ischemic attacks on the second day after CAS. Ultrasound images demonstrated incomplete in-stent thrombosis due to plaque protrusion. The urgent surgical procedure consisted of stent removal and carotid thromboendarterectomy. CASE 2: A case of complete thrombosis of a carotid stent occurred 4 days after implantation in a patient with essential thrombocythemia diagnosed by chance. The surgical strategy included stent removal and carotid thromboendarterectomy. CASE 3: Cardiac multiple embolisms in a patient with chronic atrial fibrillation caused concomitant leg ischemia and acute carotid stent occlusion 2 hours after CAS. Cerebral reperfusion was established by embolectomy, without removing the stent. At the same time, the right leg ischemia was resolved by a thromboembolectomy with a Fogarty catheter. These three cases demonstrate that acute thrombosis after carotid stenting can be managed successfully with emergent surgical intervention. Thromboendarterectomy with stent removal or in selected cases, simple thromboembolectomy, can minimize neurologic sequelae in patients suffering from acute post-stenting carotid thrombosis.

Cerebral revascularization by endovascular techniques

The minimally invasive approach to managing patients with ischemic and hemorrhagic stroke by endovascular intervention has made tremendous progress over the past years. Early recognition of stroke, improved ability to accurately diagnose the site of pathological abnormality with advanced imaging techniques and advances in treatment alternatives have led to better patient outcomes. Endovascular techniques for cerebral revascularization, a leading new therapeutic approach in the treatment of cerebrovascular disease, play a major role in both the management of acute stroke and secondary prevention. Selective intra-arterial thrombolysis for acute stroke has been performed for more than two decades with increasing success. Neurovascular therapies for secondary prevention include angioplasty of extracranial and intracranial vessels, as well as procedures for arterial reconstruction.

Technique d’exploration des vaisseaux cervicaux et encéphaliques : angioscanner

Examination of acute stroke by CT angiography is an alternative to MRI. Technological improvement of multidetector CT scanners allows neuroimaging of stroke in a multimodal protocol including plain CT, cerebral CT perfusion and CT angiography of the cervical and intracranial arteries. CT angiography is a reliable non invasive technique for the evaluation both extracranial and intracranial vessels that may be used as an alternative to MR angiography.

Dialysis Rounds: Mycotic Aneurysms and Death in a Hemodialysis Patient

ABSTRACTA patient with newly diagnosed end‐stage renal disease (ESRD) received a femoral catheter for hemodialysis (HD). Shortly thereafter he developed fever, and blood cultures grew methicillin‐resistant Staphylococcus aureus. The catheter was removed and the patient was treated with both vancomycin and rifampin; however, blood culture positivity persisted. The cerebrospinal fluid showed sterile meningitis. Subsequent imaging studies demonstrated aortic valve endocarditis and multiple mycotic aneurysms that appeared to include the intra‐ and extracranial vessels. The patient eventually died from sepsis. This case illustrates the aggressive and invasive nature of systemic infection with S. aureus and underscores the high morbidity and mortality associated with infections related to HD catheters.

Unde ex Orimur

A patient with newly diagnosed end-stage renal disease (ESRD) received a femoral catheter for hemodialysis (HD). Shortly thereafter he developed fever, and blood cultures grew methicillin-resistant Staphylococcus aureus. The catheter was removed and the patient was treated with both vancomycin and rifampin; however, blood culture positivity persisted. The cerebrospinal fluid showed sterile meningitis. Subsequent imaging studies demonstrated aortic valve endocarditis and multiple mycotic aneurysms that appeared to include the intra- and extracranial vessels. The patient eventually died from sepsis. This case illustrates the aggressive and invasive nature of systemic infection with S. aureus and underscores the high morbidity and mortality associated with infections related to HD catheters.

Transaxillary Carotid Stenting: Technical Case Report

As endovascular neurointerventions continue to evolve rapidly, angioplasty and stenting of both the extracranial and intracranial vessels have become more routine procedures. When the transfemoral approach is contraindicated or technically difficult, familiarity with alternative access techniques becomes essential. We report a successful transaxillary carotid stenting in a patient with an axillary bifemoral bypass graft. A 77-year-old man presented with a symptomatic high-grade stenosis (80%) of the left internal carotid artery. Because of the increased risk of general anesthesia related to his advanced age and severe comorbidities, stenting of the left internal carotid artery was considered. A left transaxillary approach was chosen because of the presence of an axillary bifemoral bypass graft. Under ultrasound guidance, the left axillary artery was successfully punctured and cannulated. After a 0.038 Magic Torque wire (Boston Scientific/Medi-Tech, Watertown, MA) was anchored with the tip of the wire in the distal left occipital artery, a 7-French (outer diameter) Vista Bright guiding sheath (Cordis, Miami, FL) was successfully positioned in the mid left common carotid artery, with an MPA catheter (Cordis) used as guiding support. Subsequently, two Precise stents (Cordis) were successfully deployed across the stenosis, yielding a satisfactory angiographic result. With proper patient selection and the use of ultrasound guidance during the initial puncture, the transaxillary approach is a safe and technically feasible alternative to the transfemoral approach when performing carotid stenting.

The Role of the Intrauterine and Perinatal Environment in Cerebral Palsy

Author Disclosure Drs Paneth, Korzeniewski, and Hong did not disclose any relationships relevant to this article. After completing this article, readers should be able to: 1. Discuss the prevalence of cerebral palsy (CP) in school-aged children. 2. Describe the role of neuroimaging in CP. 3. Describe the impact of ventilatory practices in low-birthweight infants on the risk of CP. 4. Delineate the role of infection and fetal inflammation in pregnancy in the development of CP. The special importance of CP to clinicians whose practices encompass pregnancy and the perinatal or neonatal period is that no other neurodevelopmental disorder bears as close a causal relationship to the hazards of intrauterine and perinatal life. Although the strength of that relationship has been exaggerated at times, especially in relation to obstetric trauma and birth asphyxia, there can be no serious doubt that adverse events in pregnancy and the perinatal period do occasionally damage the fetal or neonatal brain. A distinctive feature of brain damage produced between early gestation and infancy is destruction of cerebral white matter or extrapyramidal tracts, thereby producing a clinical syndrome in which disturbance of motor control is a prominent and probably a necessary feature. Depending on the nature and extent of the insult, the motor disorder may be predominantly spastic, dyskinetic, or ataxic and may involve all four limbs (quadriplegia), one side (hemiplegia), or be most prominent in the legs (diplegia). CP severe enough to be recognized as a disability is found in about 1 in 500 school-age children in most developed countries, with little variation between countries or over the past 30 years. (1) Because CP often is accompanied by other neurodevelopmental disabilities, particularly seizure disorders, varying degrees of mental retardation, blindness, or deafness, affected children constitute the single largest group of children in the population who have major disabilities. (2) More …

Changes in extracranial arteries in obstructive sleep apnoea

Obstructive sleep apnoea (OSA) is linked with increased cardiovascular morbidity and mortality, possibly through an enhancement of atherosclerotic vascular changes. Up to now, however, only a few studies have tried to evaluate the occurrence of atherosclerosis in patients with OSA. In the present study, ultrasonography of the large extracranial vessels was performed in a group of consecutively admitted OSA patients (n = 35) and a control group of non-OSA patients (n = 35). Common carotid artery-intima media thickness (CCA-IMT) was measured at the far wall of both proximal carotid arteries. Furthermore, the presence of plaques and stenoses of the extracranial vessels was determined. All measurements were carried out blinded to the status of the patients. In the OSA group, CCA-IMT was significantly increased when compared with the non-OSA patients and was related to the degree of nocturnal hypoxia. Additionally, the formation of plaques was more pronounced and extracranial vessel stenosis was more common in the OSA patients. In conclusion, these findings are in favour of an independent influence of obstructive sleep apnoea on atherosclerotic changes of the arterial wall, and represent further strong arguments for obstructive sleep apnoea being a risk factor on its own for the emergence of cardiovascular disease.

Ocular Flutter—A Sign of Brain-Stem Pathology as Rare Consequence of Cyclosporin A Treatment

Cyclosporin A is a widely used immunosuppressive drug. While neurotoxic side effects are frequent and manifold, oculomotor disturbances have hardly ever been noted. Here, we report the case of a 56-year-old woman, suffering from acute myeloid leukemia (AML) and treated with allogeneic peripheral blood stem-cell transplantation (PBSCT) and supporting cyclosporin, who developed neurological deficits consisting of ocular flutter, severe ataxia, and tremor of trunk and extremities within a few days. Whereas MRI scans of the neurocranium and spinal cord, Doppler ultrasound of the extracranial brain-supplying blood vessels, and the standard repertoire of electrophysiological examinations of the peripheral nerves were inconclusive, a cerebrospinal fluid tap showed an elevated cell count with leukemic blasts documenting leukemic meningitis. As soon as the cyclosporin medication, which had been initiated after the PBSCT 13 weeks earlier, was terminated, the aforementioned disturbances promptly subsided, well before treatment of the meningeosis was commenced. This temporal relationship indicates that ocular flutter as well as ataxia and tremor were caused by cyclosporin-associated neurotoxicity rather than by meningeosis. The isolated oculomotor abnormality of ocular flutter in the absence of typical cerebellar oculomotor disturbances suggests that ocular flutter might be a consequence of brain-stem dysfunction rather than reflecting cerebellar disturbances.

Painful Stimulation of the Temple Induces Nausea, Headache and Extracranial Vasodilation in Migraine Sufferers

To determine whether painful stimulation of the temple would induce nausea, ice was applied to the temple for 30 s, three times at 4-min intervals in 23 migraine sufferers and 22 age- and sex-matched controls. On one occasion, the ice was applied in the presence of residual motion sickness induced by optokinetic stimulation. On another occasion, the ice application was not preceded by optokinetic stimulation (the baseline condition). In the baseline condition, nausea had developed in migraine sufferers but not controls by the third application of ice. In the presence of residual motion sickness, each painful stimulus intensified nausea and headache in migraine sufferers whereas symptoms were minimal in controls. Changes in frontotemporal pulse amplitude were monitored with photoelectric pulse transducers. The extracranial blood vessels dilated in migraine sufferers but not controls before the first application of ice in the baseline condition, presumably due to anticipatory anxiety. In contrast, the ice application did not provoke extracranial vasodilation in either group after optokinetic stimulation. The findings show that susceptibility to nausea and stress-induced extracranial vascular hyper-reactivity are associated with the migraine predisposition. They also suggest that head pain might intensify gastrointestinal disturbances during attacks of migraine.

Methylergonovine maleate (methergine) relieves postdural puncture headache in obstetric patients

Sir, Postdural puncture headache (PDPH) is usually related to persistence of the dural hole, with leakage of cerebrospinal fluid into the surrounding soft tissue. This leads to lowering of cerebrospinal fluid pressure. This in turn produces intracranial venous dilatation resulting in an increase in brain volume (Monro–Kellie doctrine) (1). This increase in brain volume results in brain sag, which exerts traction on the surrounding nerves, vessels and meninges resulting in headache. Methylergonovine maleate (methergine) is a semisynthetic derivative of the ergot alkaloid. Stimulation of vascular smooth muscles by ergot alkaloid through their agonist action at α-adrenergic receptors is the basis for their usefulness in the treatment of migraine headaches 2-4). We planned a pilot study to evaluate the usefulness of methergine in relieving PDPH in obstetric patients based on this observation. The study was conducted on 25 obstetric patients (ASA I and II, aged 18–30 years), undergoing cesarean section under spinal anesthesia, who developed PDPH that was not relieved by bedrest, analgesics and fluids for 24 h. Following approval by the Board of Studies, these patients were administered oral tablets of methergine, 0.25 mg three times a day for 24 h. If the intensity of headache reduced or disappeared within 24 h, the treatment was carried on for a further 48 h. Tablet metoclopramide 10 mg twice a day was also advised as a prophylactic antiemetic. At 8-h intervals, patients were asked to rate their intensity of headache on a Visual Analog Scale (VAS; 1 = no headache, 10 = maximum headache). All of the patients except one (4%) showed improvement in the intensity of headache within 24 h. Of these 24 (96%) patients who responded, headache disappeared completely in four (16%) patients, and reduced to less than half in the remaining 20 (80%) (VAS < 5) in the first 24 h. By the third day all of these 24 patients were completely relieved of their headache. Only one (4%) patient who showed no improvement in her condition had to undergo the application of an epidural blood patch for relief of PDPH. The probable mechanism of action of methergine in PDPH is the vasoconstriction of cranial and extracranial vessels leading to decrease in brain volume and corresponding traction on vessels, nerves and meninges. In conclusion, this preliminary trial suggests that tablet methergine can be successfully used to relieve PDPH in postcesarean section patients.

History and Current Status of Endovascular Management for the Extracranial Carotid and Supra-Aortic Vessels

Few procedures in the history of medicine have been more controversial than carotid artery stenting (CAS) for the management of carotid artery occlusive disease. Introduced just as the randomized trials were establishing carotid endarterectomy as the gold standard for carotid interventions, CAS has finally reached the point in its development when dedicated stenting systems are being tested in randomized clinical trials. Assisted by the concomitant use of distal protection devices, CAS has shown equipoise with endarterectomy in terms of safety at 30 days. This review summarizes the completed and ongoing CAS trials and the applications of endovascular techniques in the supra-aortic vessels.