Doppler Ultrasound Flow Reversal in the Superior Sagittal Sinus to Detect Cerebral Venous Congestion in Vein of Galen Malformation.

BACKGROUND AND PURPOSE: Vein of Galen malformation is a rare congenital cerebrovascular malformation. In affected patients, increased cerebral venous pressure constitutes an important etiologic factor for the development of brain parenchymal damage. The aim of this study was to investigate the potential of serial cerebral venous Doppler measurements to detect and monitor increased cerebral venous pressure. MATERIALS AND METHODS: This was a retrospective monocentric analysis of ultrasound examinations within the first 9 months of life in patients with vein of Galen malformation admitted at <28 days of life. Categorization of perfusion waveforms in the superficial cerebral sinus and veins into 6 patterns was based on antero- and retrograde flow components. We performed an analysis of flow profiles across time and correlation with disease severity, clinical interventions, and congestion damage on cerebral MR imaging. RESULTS: The study included 44 Doppler ultrasound examinations of the superior sagittal sinus and 36 examinations of the cortical veins from 7 patients. Doppler flow profiles before interventional therapy correlated with disease severity determined by the Bicêtre Neonatal Evaluation Score (Spearman ρ = -0.97, P = < .001). At this time, 4 of 7 patients (57.1%) showed a retrograde flow component in the superior sagittal sinus, whereas after embolization, none of the 6 treated patients presented with a retrograde flow component. Only patients with a high retrograde flow component (equal or more than one-third retrograde flow, n = 2) showed severe venous congestion damage on cerebral MR imaging. CONCLUSIONS: Flow profiles in the superficial cerebral sinus and veins appear to be a useful tool to noninvasively detect and monitor cerebral venous congestion in vein of Galen malformation.

[Availability of mechanical thrombectomy for acute stroke : Analysis of the health care reality in Germany]. / Verfügbarkeit der mechanischen Thrombektomie bei akutem Hirninfarkt : Analyse der Versorgungsrealität in Deutschland.

BACKGROUND: Mechanical thrombectomy (MT) has become an evidence-based therapy for stroke patients with proximal vessel occlusion of the anterior cerebral circulation. Nationwide availability of MT for all eligible patients within the shortest possible time window is a major challenge. AIM OF THE STUDY: Nationwide analysis of the rates of systemic thrombolysis (STL) and MT in Germany according to region and hospital-based evaluation. METHODS: The evaluation involved data analysis of the diagnosis-related groups (DRG) statistics and structured quality reports of hospitals for 2010 and 2014. The rates and changes of STL and MT were evaluated in the 413 German districts with reference to the corresponding case number of patients with acute ischemic stroke. RESULTS: Nationwide recanalization treatment rates increased from 2010 to 2014 both for STL (from 8.0% to 11.6%) and MT (from 0.7% to 2.3%). High variations were observed depending on the patient's place of residence (STL = 3.4-36.7%, MT = 0-7.4%). In 2014 a total of 5526 MT were coded in a total of 244,757 ischemic strokes. A total of 134 hospitals with more than 2 MT per year were identified; however, 21% of the nationwide MTs were performed in only 7 hospitals with more than 100 MT/year. In 308 (75%) of the 413 districts, not a single MT was performed. CONCLUSION: Due to a narrow net of certified stroke units with nationwide availability of STL, excellent structural conditions for treatment of acute stroke patients are already established in Germany. With regard to the nationwide availability of MT, there is still a need for optimization. Despite the increasing number of hospitals providing MT as an emergency procedure, a trend toward large intervention centers with supraregional catchment areas can be observed.

Evolution of Embolic Agents in Interventional Neuroradiology.

The growth in understanding of the pathophysiological relationships between various neurovascular diseases in the past decades has increased the significance and need for endovascular treatment. Consequently, an extraordinary development of different embolic agents was indispensable. The present work first presents the historical milestones in the discovery of various embolic materials used for neurovascular interventions. In the second part, the current endovascular embolization procedures, requiring both liquid and solid embolic agents, are discussed. In some cases and diseases the combination of both may be mandatory. Special emphasis is placed on the consideration needed when choosing appropriate embolic materials, chiefly depending on the goal of the endovascular procedure. Furthermore, the present understanding of the specifics in angioarchitecture and hemodynamics, leading to the most suitable form of access to the vascular lesion, will be covered. Regarding the latter, it is important to note that the aim should always be to achieve optimal superselectivity while being aware of all approaches, ranging from transarterial and transvenous to direct puncture. Finally, based on the limitations of the currently available embolic materials, we present a brief outlook on the future of new liquid and solid embolic agents.

Superselective microcoil embolization in severe intractable epistaxis: an analysis of 12 consecutive cases from an otorhinolaryngologic and an interventional neuroradiologic point of view.

From 2006 to 2013, 12 patients with severe epistaxis refractory to prior conservative and surgical therapy were treated by superselective embolization of nasal arteries. Supersoft platinum microcoils with smallest diameters were used as the sole embolic agent in all cases. Coils were applied far distally in a stretched position for obtaining ideal target vessel superselectivity. The objective of this study is to evaluate efficacy and complications of superselective coil embolization for treatment of severe intractable epistaxis and to discuss results from an otorhinolaryngologic and an interventional neuroradiologic point of view. Retrospectively, all epistaxis inpatients between 2006 and 2013 were identified and subdivided by form of treatment: conservative, surgical and interventional therapy. Medical records of interventionally treated patients were reviewed for demographics, medical history, risk factors, clinical data, complications and short-term success, and patients were followed up for long-term success. Mean follow-up was 37 months. In 12 patients, 14 embolizations were carried out, with short-term success in 9 patients (75%), while early post-interventional rebleeding occurred in 3 patients (25%). Of 9 patients with short-term success, 1 died during stay, 1 was lost to follow-up and 1 had minor re-bleeding after 30 months. Six patients had short-term and long-term success. Before the first embolization, 3 ± 1 conservative and/or surgical procedures had been undertaken. Length of stay was 12.8 ± 3.6 days. 8 patients (67%) received red cell concentrates. Most frequent complications were mucosal damage and nasal pain, but these were related to repeated packing and surgery. Typical embolic complications as neurological or visual impairment or soft tissue necrosis were not observed in any patient. From the otorhinolaryngologic point of view, surgery is the treatment of choice in severe refractory epistaxis, but in case of repeated failure, superselective microcoil embolization is a valuable addition to the therapeutic spectrum. From the interventional neuroradiologic point of view, superselective microcoil embolization is an effective, well tolerable and safe procedure and complications may be reduced in comparison to microparticle embolization. Modern supersoft microcoils with smallest diameters enable ideal superselectivity of the target vessels.

Treatment of middle cerebral artery occlusion and internal carotid artery dissection with combined mechanical thrombectomy and stenting of the internal carotid artery. A case report.

We describe a case of combined mechanical thrombectomy of the right middle cerebral artery and stent angioplasty of the right internal carotid artery in a severe stroke caused by arterio-arterial embolism due to a traumatic dissection of the internal carotid artery. The patient was admitted with an NIHSS score of 19 and was discharged from hospital with a score of 2. Three months later neurological examination disclosed no pathological findings. The case demonstrates the crucial role of interventional procedures in the treatment of severe stroke where intravenous thrombolysis has little prospect of success.

Origin and course of the extracranial vertebral artery: CTA findings and embryologic considerations.

PURPOSE: The aim of this study was to show the different origins and courses of the extracranial VA on CTA with special emphasis on embryological considerations. The duplicated VA is an anomaly that has been assumed to predispose for dissection and to be associated with aneurysms. We report its frequency and clinical significance. METHODS: We retrospectively reviewed CTA of 539 patients by using a contrast-enhanced CTA protocol of the VA on CT. RESULTS: Ninety-four-point-two percent of left VA originated from left subclavian artery and entered the transverse foramen at C6 in nearly all cases. Six-point-three-percent of left VA (m = 4 %, f = 10 %) originated from the aortic arch and entered the transverse foramen either at C4, C5 or C7 but never at C6. One case of an aberrant retroesophageal right VA originated from the aortic arch distal to the left subclavian artery and entered at C7 (0.19 %). All other right VA originated from the right subclavian artery (99.8 %) and entered between C4 and C6. We diagnosed four cases of duplicated VA (0.74 %) with a female predominance (1.9 %) without any signs of dissection on CTA. Two cases with VA duplication had intracranial arterial aneurysms. CONCLUSIONS: The VA is a longitudinal anastomosis of segmental metameric arteries. The level of entrance into the transverse foramen indicates which metameric artery or arteries persist. Duplication corresponds to persistence of two segmental arteries and is a rare phenomenon. VA duplication might be associated with vascular lesions.

[Vascular interventions in the head and neck region. part 2: procedures for vessel occlusion]. / Vaskuläre Interventionen im Kopf-Hals-Bereich. Teil 2: Gefäßverschließende Verfahren.

As a result of continuing progress in the development of intervention materials but also due to growing understanding of pathophysiological relationships, the prevalence and significance of endovascular interventions in the head and neck region have continued to increase. This applies to procedures for recanalization, which were addressed in detail in an earlier article, as well as to techniques used for vessel occlusion. This contribution first presents the techniques and materials employed in embolization in the head and neck region. Based on this description the application of endovascular procedures for vessel occlusion are explained with respect to different disease entities in the head and neck region. In this context particular attention is given to the treatment of intracranial aneurysms, cerebral arteriovenous malformations, dural AV fistulae, vascular malformations, and tumors in the head and neck region.

[Vascular interventions in the head and neck region. Part 1: Recanalization procedures]. / Vaskuläre Interventionen im Kopf-Hals-Bereich. Teil 1: Rekanalisierende Verfahren.

Vascular interventions in the head and neck region are becoming increasingly more important due to acquisition of knowledge on the pathophysiological principles of various vascular diseases and the development of new intervention materials. This article gives a review of the materials and techniques used in interventions in the head and neck region. Special attention is given to the description of a safety-oriented approach to avoid potentially severe complications. Based on this the value of endovascular therapeutic procedures for recanalization of various diseases will be discussed, in particular the treatment of extracranial and intracranial stenoses and the reopening of vascular occlusions in acute stroke using PTA, stents, lysis and mechanical thrombus removal.

[Modern cross-sectional imaging of head and neck vessels]. / Moderne Schnittbildgebung der Kopf-Hals-Gefässe.

Although digital subtraction angiography (DAS) remains the gold standard for neurovascular imaging, the number of diagnoses made on the basis of less invasive cross-sectional imaging techniques (CT and MR angiography) is increasing. The present article provides important technical principles of CT and MR angiography, followed by an analysis of the diagnostic possibilities and limitations of vascular cross-sectional imaging. The particular importance of post-processing of vascular cross-sectional datasets is also discussed. Using the typical clinical diagnostic work-up of extra- and intracranial vascular diseases as a basis, the article explains how a suitable examination technique and protocol is chosen and which limitations need to be borne in mind. After taking at look at the technical advances expected in the future (3-Tesla MRA, dual-energy CTA, post-processing workflow in PACS), the remaining indications for diagnostic DSA will be presented and explained.

Intravascular stent placement for a fusiform aneurysm of the posterior cerebral artery: case report.

This article presents the case of a 45-year-old woman with a fusiform, broad-based, actually ruptured aneurysm of the posterior cerebral artery. The patient was successfully treated with stent placement and follow-up angiography demonstrated occlusion of the dome and the body of the aneurysm. Due to the limited neurosurgical treatment options, stent placement should be considered in patients with fusiform aneurysm of the posterior cerebral artery aneurysms.

Carotid artery stenting in patients at surgical high risk: clinical and ultrasound findings.

Angioplasty and stenting (A/S) provide an alternative for patients with simultaneous severe cardiac and cerebrovascular disease, or with medical illnesses which carry a high perioperative risk. We conducted A/S in 20 high-risk patients (15 males, 5 females, mean age = 64.5 years, range = 49-83 years) with symptomatic (n = 16) and asymptomatic (n = 4) high-grade stenosis (>70%, NASCET criterion) of the internal carotid artery. Patients had neurological examinations before, during and after the procedure. Color-coded duplex sonography was performed before and 24 h and every 3 months after the procedure; the 3-month examination also included cerebral angiography. The mean degree of stenosis was reduced from 85.75 +/- 7.47 to 8.0 +/- 22.09% in angiography. In an 18-month follow-up with color-coded duplex sonography the effects of the A/S could be visualized effectively: 2 with local, transient vasospasms, 1 with asymptomatic occlusion, 2 carotid arteries with remaining stenosis of 50% and 2 with minimal hyperplasia within the stent. In conclusion, in patients with a high perioperative risk, A/S is a therapeutic alternative to surgery.

Transcranial duplex sonography of middle cerebral artery stenosis: a comparison of colour-coding techniques--frequency- or power-based Doppler and contrast enhancement.

The main limitation of transcranial colour-coded duplex sonography (TCCD) is the inadequate acoustic window, which prevents transtemporal identification of the basal cerebral arteries in up to 30% of cases, especially in the elderly. TCCD with different colour-coding techniques, including frequency-based colour-flow (CFD) or power (PD) Doppler sonography, used alone or in combination with contrast media, were used in 23 patients with middle cerebral artery (MCA) stenosis. In 10 patients a contrast medium (400 mg/ml SHU 508 A) was administered because of inadequate colour-coded visualisation with TCCD. The data were compared with angiographic methods. Digital subtraction angiography (DSA) revealed 2 low-grade, 11 middle-grade and 10 high-grade stenoses in the M1 segment. With TCCD, we found a 7.7% higher blood flow velocity (systolic peak velocity) than with transcranial duplex sonography without colour-coding because of visual angle correction and a 20% higher systolic peak velocity using contrast enhancement. CFD did not differ from PD in identification of low- and middle-grade MCA stenoses, but PD alone revealed two more cases of high-grade stenosis than CFD. The contrast medium increased diagnostic confidence in 8 of 10 cases. Only 2 of 23 MCA stenoses (9%) could not be shown using TCCD.

Transcranial power mode Doppler duplex sonography of intracranial aneurysms.

The application of different color-coding techniques in transcranial color-coded duplex sonography (TCCD) was assessed for detection and measurement of the size of intracranial aneurysms. Thirty-two consecutively examined patients with 36 angiographically verified cerebral aneurysms underwent TCCD with color Doppler flow imaging (CDFI), power Doppler imaging (PDI), and both methods with contrast enhancement. The diameters of the aneurysms were measured in comparable planes by means of angiography and TCCD-PD with and without 400 mg/ml of the monosaccharide microparticle contrast agent Levovist. TCCD with CFD enabled detection of 27 of 36 aneurysms (75%), and PD depicted 29 aneurysms (80%). After administration of Levovist, an additional two aneurysms were detected with CFD and three with PD color coding. Measurements of aneurysm size obtained by means of PD with contrast enhancement corresponded more highly with angiographic findings than did measurements obtained with PD alone. Use of alternative color-coding techniques with the addition of contrast agents increases the number of intracranial nonthrombosed aneurysms detectable with TCCD.

The role of spinal angiography in operations on the thoracic aorta: myth or reality?

BACKGROUND: The importance of preserving the artery of Adamkiewicz during replacement of the thoracoabdominal aorta is debated. We report our experience with the use of preoperative spinal angiography and modification of the surgical technique. METHODS: Between September 1993 and March 1996, 46 patients (mean age, 57 years; range, 25 to 73 years) underwent spinal angiography at our institution, 23 for an aneurysm and 23 for chronic dissection. Localization of the artery of Adamkiewicz between T-9 and L-3 was successful in 30 (65%) patients: T-9, left = 2, right = 1; T-10, left = 4; T-11, left = 10, right = 2; T-12, left = 3, right = 1; L-1, left = 1, right = 2; L-2, left = 2, right = 1; and L-3, left = 1. Thirty-one patients subsequently underwent replacement of the descending thoracic aorta and 13 underwent replacement of the thoracoabdominal aorta. Left atrial-femoral artery bypass was used in 23 patients and full extracorporeal circulation was used in 20 patients. Twelve procedures included the reimplantation of crucial intercostal/lumbar branches. RESULTS: The operative mortality rate was 6.8% (3 of 44 patients) and 1 (2.27%) patient had paraparesis. In addition to the 12 patients who underwent targeted reimplantation of the intercostal branches, evaluation of the spinal cord blood supply influenced the operative technique in 19 other patients. CONCLUSIONS: Selective angiography can demonstrate the spinal cord blood supply even in patients with complex aortic pathology. It is a helpful tool for planning extensive replacement of the thoracic and thoracoabdominal aorta.

Breakdown of the meningeal barrier surrounding the intraorbital optic nerve after experimental subarachnoid hemorrhage.

PURPOSE: The intraorbital optic nerve sheath meninges contain a perineural subarachnoid space lined by meningeal cell layers and intercellular fibrous tissue. We sought to determine whether functional or structural characteristics, or both, of the optic nerve sheath are influenced by the increased intracranial pressure after the rupture of cerebral aneurysms. METHODS: We infused the great cisterns of cats with either x-ray contrast medium or autologous blood. The cisternal infusions were done under the experimental condition of a sudden 2.5-minute increase in intracranial pressure similar to that recorded after the rupture of cerebral aneurysms in humans. RESULTS: Digital subtraction radiographs of the optic nerves taken during the cisternal infusion of contrast medium at the start showed the opacification of the optic nerve subarachnoid space. After 2 minutes, the contrast medium leaked into the orbit, indicating the breakdown of the meningeal fluid barrier. Ultrastructural investigation of the optic nerve sheath after high-pressure cisternal infusions showed the arachnoid cell layers scattered. The flattened arachnoid cells displayed mainly intracellular and some intercellular, porelike openings. After infusion of blood into the great cistern, erythrocytes were found within porelike openings of the arachnoid cells. CONCLUSIONS: The meningeal fluid barrier of the optic nerve sheath can be destroyed by pressure changes associated with subarachnoid hemorrhage. This disruption might be regarded as a natural optic nerve sheath fenestration that allows outflow of cerebrospinal fluid into the orbit to protect the optic nerve from increased intracranial pressure after aneurysmal rupture.

[Possibilities and limitations of CT angiography in comparison to DSA in intracranial aneurysm]. / Möglichkeiten und Grenzen der CT-Angiographie im Vergleich zur DSA bei intrakraniellen Aneurysmen.

PURPOSE: The purpose of this study was to determine the value of CT angiography in the detection of intracranial aneurysms and to discuss its qualities compared with DSA. METHODS: 26 patients with subarachnoid bleeding confirmed by unenhanced CT or lumbar puncture were examined with CT angiography. In 23 of these patients results of DSA were available. RESULTS: In 21 cases 30 aneurysms were found with DSA, whereas in two cases there were no aneurysms. The size of the aneurysms was between 3 and 36 mm. With CT angiography two small 3 mm aneurysms were not detected. In three patients with vasospasms the diagnosis was primarily confirmed by CT angiography. The sizes measured by CTA and DSA were approximately the same. CONCLUSION: Because of the limited spatial resolution small aneurysms (< 5 mm) could not be diagnosed in CTA. Definitive exclusion of aneurysms is therefore not possible. Aneurysms larger than 5 mm are reliably diagnosed. CTA is indicated if identification of the bleeding aneurysm is sufficient for further patient management.

A proposed modification of the Wada test for presurgical assessment in temporal lobe epilepsy.

We report experience with a modification of the Wada test used before temporal lobe resection in patients with drug-resistant epilepsy. Our procedure consists of injection of amytal via a microcatheter into the anterior choroidal artery or the P2 segment of the posterior cerebral artery and simultaneous presentation of verbal and figural memory test material before, during and after the injection. Pros and cons of the modification and inherent shortcomings of the amytal test are discussed on the basis of the results in ten patients.