bluuebunny/crossref_metadata_2025 huggingface dataset:
Inverse Halogen Bonds Interactions Involving Br Atom in the Electronic Deficiency Systems of CH3⊕ ··· Br—Y (Y=H, CCH, CN, NC)
Authors: Liu Yan-zhi , Yuan Kun , Lv Ling-ling , Zhu Yuan-cheng , Tang Hui-an , Zuo Guo-fang , Li Zhi-feng
Published: July 2011

Inverse halogen bonds interactions involving Br in the electronic deficiency systems of CH3⊕ ··· Br—Y (Y=H, CCH, CN, NC) have been investigated by B3LYP/6-311++G(d, p) and MP2/6-311++G(d, p) methods. The calculated interaction energies with basis set super-position error correction of the four IXBs complexes are 218.87, 219.48, 159.18, and 143.05 kJ/mol (MP2/6-311++G(d, p)), respectively. The relative stabilities of the four complexes increased in the order: CH3⊕ ··· BrCN<CH3⊕ ··· BrNC<CH3⊕ ··· BrH≈CH3⊕ ··· BrCCH. Natural bond orbital theory analysis and the chemical shifts calculation of the related atoms revealed that the charges flow from Br—Y to CH3⊕. Here, the Br of Br—Y acts as both a halogen bond donor and an electron donor. Therefore, compared with conventional halogen bonds, the IXBs complexes formed between Br—Y and CH3⊕. Atoms-in-molecules theory has been used to investigate the topological properties of the critical points of the four IXBs structures which have more covalent content.
TDDFT Study on Different Sensing Mechanisms of Similar Cyanide Sensors Based on Michael Addition Reaction
Authors: Li Guang-yue , Song Ping , He Guo-zhong
Published: July 2011

The solvents and substituents of two similar fluorescent sensors for cyanide, 7-diethylamino-3-formylcoumarin (sensor a) and 7-diethylamino-3-(2-nitrovinyl)coumarin (sensor b), are proposed to account for their distinct sensing mechanisms and experimental phenomena. The time-dependent density functional theory has been applied to investigate the ground states and the first singlet excited electronic states of the sensor as well as their possible Michael reaction products with cyanide, with a view to monitoring their geometries and photophysical properties. The theoretical study indicates that the protic water solvent could lead to final Michael addition product of sensor a in the ground state, while the aprotic acetonitrile solvent could lead to carbanion as the final product of sensor b. Furthermore, the Michael reaction product of sensor a has been proved to have a torsion structure in its first singlet excited state. Correspondingly, sensor b also has a torsion structure around the nitrovinyl moiety in its first singlet excited state, while not in its carbanion structure. This could explain the observed strong fluorescence for sensor a and the quenching fluorescence for the sensor b upon the addition of the cyanide anions in the relevant sensing mechanisms.
Synthesis of Schiff Base Bearing Phenolic Hydroxy Group and Its Anion Recognition
Authors: Liu Ge , Gao Ling
Published: July 2011

A new anion receptor bearing phenolic hydroxy group based on 3,5-ditertbutylsalicylaldehyde-p-nitrophenylhydrazone (1) was designed and synthesized. Upon addition of AcO− and F−, the receptor exhibited visible color changes from deep yellow to purple. However, no obvious color changes were observed on addition of the other anions tested (H2PO4−, Cl−, Br−, I−). The binding properties of the receptor with anions such as AcO− and F− were investigated by UV-Vis and fluorescent titrations. The result indicated that the receptor 1 had a higher affinity to AcO− and F− and a 1:1 host-guest complex was formed through H-bond interactions between 1 and anions.
Direct Synthesis of Phenol from Benzene on an Activated Carbon Catalyst Treated with Nitric Acid
Authors: Chen Cui-hong , Xu Jia-quan , Jin Ming-ming , Li Gui-ying , Hu Chang-wei
Published: July 2011

Commercially available coal-based activated carbon was treated by nitric acid with different concentrations and the resultant samples were used as catalysts for the direct hydroxylation of benzene to phenol in acetonitrile. Boehm titration, X-ray photoelectron spectroscopy, scanning electron microscope coupled with an energy dispersive X-ray microanalyzer, and Brunauer-Emmett-Teller method were used to characterize the samples. The number of carboxyl groups on the surface was found to be the main factor affecting the catalytic activity. An optimum catalytic performance with a yield of 15.7% and a selectivity of 87.2% to phenol was obtained.
Localized reactive badger culling increases risk of bovine tuberculosis in nearby cattle herds
Authors: Vial Flavie , Donnelly Christl A.
Published: July 2011

Human and livestock diseases can be difficult to control where infection persists in wildlife populations. Control of bovine tuberculosis (bTB) in British cattle is complicated by the maintenance ofMycobacterium bovis(the causative agent of bTB) in badgers, acting as reservoirs of infection. Although over 20 000 badgers were culled to control bTB between 1975 and 1997, the incidence of bTB in cattle has substantially increased in parts of Great Britain in recent decades. Our case-control study, involving 1208 cattle herds, provides further evidence of the detrimental effect of localized reactive badger culling in response to the disclosure of a confirmed bTB herd breakdown in cattle. The presence of any reactive badger culling activity and increased numbers of badgers culled in the vicinity of a herd were associated with significantly increased bTB risk, even after adjusting for other important local risk factors. Such findings may partly explain why some earlier localized approaches to bTB control were ineffective.
Women's alcohol consumption and risk for alcohol‐exposed pregnancies in Russia
Authors: Balachova Tatiana , Bonner Barbara , Chaffin Mark , Bard David , Isurina Galina , Tsvetkova Larissa , Volkova Elena
Published: July 2011

Aims  Alcohol‐exposed pregnancies (AEP) are the direct cause of fetal alcohol spectrum disorders (FASD). This study examines drinking patterns among pregnant and non‐pregnant women of childbearing age in Russia, a country with one of the highest levels of alcohol consumption in the world.

Design  Cross‐sectional survey.

Setting  Seven public women's clinics in two locations: St Petersburg (SPB) and the Nizhny Novgorod region (NNR).

Participants  A total of 648 pregnant and non‐pregnant childbearing‐age women.

Measurements  A face‐to‐face structured interview assessed alcohol consumption, pregnancy status/possibility of becoming pregnant and consumption before and after pregnancy recognition.

Findings  Eighty‐nine per cent of non‐pregnant women reported consuming alcohol and 65% reported binge drinking in the past 3 months; 47% in NNR and 28% in SPB reported binges at least monthly. Women who might become pregnant consumed alcohol similarly to women who were not likely to become pregnant, and 32% of women in SPB and 54% in NNR were categorized as at risk for AEP. There was a significant decline in drinking after pregnancy identification. Twenty per cent of pregnant women reported consuming alcohol and 6% in SBP (none in NNR) reported binge drinking; however, a high prevalence of binge drinking was found among women who might become pregnant or who were trying to conceive.

Conclusions  Russian women substantially reduce drinking after pregnancy recognition compared to pre‐pregnancy levels. No reductions were found prior to pregnancy recognition, either when a woman might become pregnant or when she was trying to conceive. The pre‐conception period presents a risk window and, therefore, a prevention opportunity.
Bilingual teaching in nursing education in China: Evolution, status, and future directions
Authors: He Wei , Xu Yu , Zhu Jianhua
Published: July 2011

Based on Chinese published literature and personal observations, this article reviews the history of bilingual teaching in nursing education in China, describes its current status and challenges, and predicts its future directions. Bilingual teaching in nursing education enjoys increasing popularity in China. The major factors that affect bilingual teaching are bilingual educators, students' English‐language levels, bilingual teaching materials, and teaching models. Based on surveys of nursing schools, the English‐language proficiency of the nursing educators varies greatly. The main issues with the teaching methods lie in over‐translation, cramming, and limited interaction between the students and the teachers. Despite relatively inadequate English‐language proficiency among Chinese nursing students, their interest can be strengthened greatly if international exchanges are available and promoted. Bilingual textbooks are more suitable in China's national context because of pricing and relevance. Although immersive bilingual teaching is the ideal, it is more feasible to begin with infiltrative bilingual teaching and move progressively towards increased English‐language penetration. Future directions for improving bilingual teaching include training teaching faculty members, strengthening international exchanges, providing better bilingual study atmospheres, and gradually implementing bilingual textbooks.
Impacts of longfin eels (Anguilla dieffenbachii) on the behaviour of common bullies (Gobiomorphus cotidianus) held in captivity
Authors: Jellyman Donald J. , Crow Shannan K. , Robinson Peter
Published: July 2011

Abstract –  Interactions between common bullies (Gobiomorphus cotidianus) and longfin eels (Anguilla dieffenbachii) were studied in aquaria where bullies were subject to one of four treatments – bullies alone (allopatry), bullies and an eel (sympatry), or bullies provided with either visual cues (eel in adjacent compartment of the aquarium) or odour cues (eel in separate upstream aquarium). The total time that bullies were active (movement) and their use of rocks were recorded continuously over 48 h with a video camera. Analysis showed that for movement, there were no significant differences between treatments, but there were diel differences within sympatric treatments with greater activity evident during the night than during the day. In contrast, the use of rocks showed significant differences both between and within treatments; again, the only significant diel difference was in sympatry. Post hoc tests between treatments revealed that there were no differences at night, but during the day, there were differences between allopatry and visual trials, sympatry and visual trials, and sympatry and odour trials. No predation or other aggressive behaviour by eels towards bullies was observed in any trial. It was concluded that the presence of eels affected both bully activity and use of rocks, but this response was not solely due to either visual or odour cues. Changes in movement and the use of rocks appear to require multiple cues, and denial of either visual or odour cues was insufficient to elicit a response.
Intraspecific competition in Zabrotes subfasciatus: Physiological and behavioral adaptations to different amounts of host
Authors: Teixeira Isabel R.V. , Zucoloto Fernando S.
Published: July 2011

Abstract  The effects of competition on populations of the bean weevil Zabrotes subfasciatus were analyzed during 41 generations under different competition levels. Three competition environments were established by maintaining the number of couples (6) and varying the amount of available host seeds: HC, high (limited availability of host: 1.35 g); IC, intermediate (intermediate availability of host: 6 g); and LC, low competition (abundance of host: 36 g). It was found that the distribution of the eggs laid on grains was different among treatments: in LC, for example, although females showed high fecundity (35.4 ± 5.6 eggs/female) the number of eggs laid on each grain was small (1.2 ± 0.4 eggs on each seed), thus avoiding larval competition of their offspring; whereas in HC treatment, females showed low fecundity (27.04 ± 4.5 eggs/female) but laid many eggs on each grain (15.03 ± 4.3 eggs). There were no changes in the ability to respond to different amounts of host via oviposition behavior (egg distribution) during 41 generations. However, HC females had more offspring than LC females under HC conditions. This suggests that HC insects evolved toward higher fitness in crowded conditions. In addition, after inverting the competition level, insects behaved independently of the treatment conditions they experienced through generations, thus showing that oviposition behavior is flexible. Taken together, our results show that Z. subfasciatus presents a broad range of behavioral and physiological responses which allows for quick and reversible adjustments to sudden changes in the amount of resources.
O-018 Long-term anatomical results after endovascular treatment of ruptured intracranial aneurysms with GDC and Matrix coils: analysis of the CLARITY series
Authors: Cognard C , Pierot L , Ricolfi F , Anxionnat R
Published: July 2011

Purpose

CLARITY is a prospective, multicenter, consecutive series including patients treated with GDC or Matrix coils for ruptured aneurysms. Long-term anatomical results are presented.

Materials and Methods

Postoperative and long-term anatomical results were evaluated anonymously and independently by two experienced neuroradiologists using the 3-point Modified Montreal scale.

Results

Post-operative and long-term anatomical results were evaluated in 517/649 patients (79.7%). In the long-term follow-up, complete occlusion was reported in 95/276 aneurysms (34.4%) in the GDC group and 80/241 aneurysms (33.2%) in the Matrix group, neck remnant in 127/276 aneurysms (46.0%) in the GDC group and 118/241 aneurysms (49.0%) in the Matrix group, and aneurysm remnant in 54/276 aneurysms (19.6%) in the GDC group and 43/241 aneurysms (17.8%) in the Matrix group (p=0.780). Direct comparison of long-term vs immediate post-operative aneurysm occlusion showed improvement in 35/272 aneurysms (12.9%) in the GDC group and 27/239 aneurysms (11.3%) in the Matrix group, stable situation in 98/272 aneurysms (36.0%) in the GDC group and 97/239 aneurysms (40.6%) in the Matrix group, and worsening in 139/272 aneurysms (51.1%) in the GDC group and 115/239 aneurysms (48.1%) in the Matrix group (p=0.555). During the follow-up period, a total of 32/517 patients were retreated: 9/276 (3.3%) in the GDC group and 23/241 (9.5%) in the Matrix group (p=0.003).

Conclusions

1-year anatomical results are not different in patients with ruptured aneurysms treated with GDC or Matrix coils. Similarly, the evolution of aneurysm occlusion is not different in patients treated with GDC or Matrix coils.
O-021 Hospitalization costs for endovascular and surgical treatment of unruptured cerebral aneurysms in the USA are substantially higher than medicare payments
Authors: Brinjikji W , Kallmes D , Lanzino G , Cloft H
Published: July 2011

Background and Purpose

Endovascular and surgical options are both available for the treatment of unruptured cerebral aneurysms. Knowledge of the costs for hospitalization of these patients is important to understanding economic impact of these patients on hospitals.

Methods

Using the National Inpatient Sample, hospitalizations for clipping and coiling of unruptured cerebral aneurysms from 2001 to 2008 were identified by cross-matching ICD-9 codes for diagnosis of unruptured aneurysm with procedure codes for clipping or coiling of cerebral aneurysms, and excluding all patients with diagnosis of subarachnoid hemorrhage and intracerebral hemorrhage. Hospital costs for 2008 were correlated with age, gender, and discharge status, and compared to Medicare payments.

Results

Costs of both clipping and coiling have increased from 2001 to 2008. The median 2008 hospital costs were US$23 574 (IQR 18233–29941) for clipping and US$25 734 (IQR 17436–35846) for coiling without complication, which were higher than the average Medicare payment of US$12 599. The median hospital costs were US$36 188 (IQR 21831–55308) for clipping and US$40 502 (IQR 24289–50108) for coiling treatments complicated by major morbidity, and US$68 165 (IQR 32972–100211) for clipping and US$56 020 (IQR 00000–00000) for coiling treatments complicated by mortality, which were higher than the average Medicare payments for patients with major complications and comorbidities of US$22 946. In multivariate analysis, female gender was associated with higher costs for coiling (p=0.02), and poor discharge status was associated with higher costs for both clipping (p<0.001) and coiling (p<0.001).

Conclusions

Hospitalization costs for patients undergoing clipping and coiling of unruptured cerebral aneurysms are substantially higher than Medicare payments.
O-025 The WEB aneurysm embolization device: design, evolution and CFD evaluation
Authors: Strother C , Jiang J , Pulfer K , Consigny D
Published: July 2011

Experience with a variety of intra-luminal “flow diverters” has demonstrated the ability of these high-density, metallic mesh devices to disrupt flow into intracranial aneurysms to a degree where thrombosis will occur. Thus far, limitations in their use includes the inability to treat aneurysms of some geometries, for example, bifurcation, as well as the need for the use of dual antiplatelet therapy during, immediately after and for some months following treatment. Over the last 3 years Sequent Medical has designed and developed a novelintra-saccularflow diverter aimed at expanding the utility and ease of use of these devices in aneurysm treatment. In this presentation I will illustrate some of the steps in the development, testing and evolution of the WEB as well as describe and illustrate a computational comparison of the flow diversion achieved by use of a Sequent WEB device or a genericintra-luminalflow diverter in two human aneurysms. Since 2007 we have evaluated a variety of WEB designs using the canine bifurcation aneurysm model. Our aim in these studies was to identify a design which allowed: (1) controlled and reproducible device delivery, retrieval and detachment; (2) aneurysm isolation from the circulation within minutes of deployment; (3) stable aneurysm occlusion at follow-up. A final device design consisting of a high density, two-layer nitinol mesh with variable porosity was selected for clinical use. Using examples from our canine studies, I will discuss and illustrate how changes in pore distribution (density), pore size and the addition of an internal compartment impacted the WEBs performance. To assess the differences between the extent of flow diversion achieved by the WEB as compared to a generic intra-luminal flow diverter, we performed computational studies comparing the two devices imbedded in two human aneurysms from our in-house data base (one a ICA sidewall aneurysm and the other a basilar apex aneurysm). To reduce computational requirements a porous media approach was used for these simulations. In these two aneurysms a comparison of the TA-WSS, flow entering the aneurysms and, changes in a surrogate of kinetic energy before and after virtual “treatment” all indicated potential advantages of the WEB over the generic intra-luminal device. Over the course of our studies, the Sequent WEB evolved into a device that was effective in the treatment of the canine bifurcation aneurysm. Computational studies in two human aneuyrms illustrate the potential advantages of this intra-saccular flow diverter over a generic intra-luminal flow diverter.
O-029 Hemorrhagic complications following the endovascular treatment of brain AVMs
Authors: Baharvahdat H , Blanc R , Pistocchi S , Bartolini B , Piotin M
Published: July 2011

Purpose

The intracranial hemorrhage is the most important complication during or after embolization of brain arteriovenous malformations (AVM). This study was designed to identify the possible risk factors related to intracranial bleeding during and after embolization of brain AVMs.

Material and Methods

The 474 consecutive embolization procedures of AVMs, performed in Neurointerventional service of Rothschild Foundation, Paris, France, were studied retrospectively .The clinical and morphological characteristics of them were reviewed and analyzed.

Results

The mean age of patients was 32.2 years±13.8 (SD). The AVMs were located cortically in 70%, deep in 20%, and infratentorial in 10%. The most common clinical presentations were hemorrhage in 46% of cases and seizure in 23%. The procedural complications were intracranial bleeding (12%), catheter-related problems (10%), and ischemia (3.7%). The Onyx volume injected in procedures with hemorrhagic complications was more than the ones without hemorrhagic complications (p=0.020). The intracranial bleeding was not related to the patients' age (p=0.2), nidus size (p=0.59), hemorrhagic presentation of AVM (p=0.54), the spetzler-Martin grade of AVM (p=0.75), and location of AVM (deep-infratentorial vs cortical, p=0.28). The hemorrhagic complication was not different between the procedures used detachable microcatheter and the procedures used nondetachable microcatheter (p=0.61).

Conclusions

According to results of this study, in neuroendovascular treatment of AVMs, the onyx volume injected during the procedure can affect the development of intracranial bleeding.
O-033 Radiation savings in pediatric angiographic procedures by incorporation of extra-low dose settings into procedure time-out
Authors: Morris P
Published: July 2011

Background

With the introduction of the Artis Zee Siemens biplane neuroangiographic suite into our department, radiation exposure and skin-dose estimates were collected prospectively on all pediatric procedures using ultra-low exposure settings beyond those recommended by the manufacturer. Pediatric “Minus” settings for fluoroscopy were set at 3 fps and 18 nGy/p (default 7.5–10 fps and 23 nGy/p). Setting this low-dose protocol was incorporated into our pre-procedure “Timeout” to assure compliance.

Methods

Estimates of radiation dose were reviewed for 10 consecutive diagnostic and 10 interventional pediatric procedures. These results were compared with exposure parameters recorded using fluoroscopy and DSA with an adult size phantom using our pediatric low dose, the manufacturer's recommended pediatric settings, our adult low dose protocol, and the manufacturer's default adult settings.

Results

Estimated skin dose per case varied from 45.1 to 1888 mGy and Dose-Area-Product (DAP) varied from 27.2 to 5426 microGym2. The lower tier of exposures were all diagnostic procedures. For diagnostic procedures fluoroscopy related DAP readings accounted for 1.7–11.5% of the total DAP reading, and fluoroscopy accounted for 1–17% of the total estimated skin dose. For embolization procedures fluoroscopy accounted for 19–55.6% of DAP readings, and for 20–58% of estimated skin dose. Phantom DAP readings and estimated skin dose using a gamut of protocols suggest that fluoroscopy radiation readings using our pediatric minus protocol represent a dose savings of up to 88% compared with using an adult manufacturer's default setting at 7.5 fps at similar magnification. Phantom runs of DSA using Pediatric and Adult settings estimated a radiation dose reduction of at least 75% in DAP readings and 65% in skin dose compared with manufacturer adult default settings.

Conclusion

Physician compliance with use of lower-dose pediatric radiation protocols for neuroangiographic procedures has the potential to result in substantial reduction of patient dose compared with likely doses accrued through inadvertent conduct of the case in default or adult settings. Fluorocopy settings are proportionately a larger component of the total dose during interventional procedures, underscoring the importance of compliance with manual fixing of protocol settings at the beginning of each case.
P-004 Endovascular management of acute ischemic stroke based on perfusion studies: a single center experience
Authors: Sharma J , Shams T , Blackham K , Hsu D , Tarr R , Sunshine J
Published: July 2011

Background

CT Perfusion or MR perfusion studies are often used to evaluate patients who presents with Acute Ischemic Stroke (AIS). Little published data are available regarding the real-time use of perfusion imaging to guide endovascular management.

Objective

To evaluate the role of perfusion imaging in selection and decisions for endovascular management in AIS patients.

Methods

Retrospective chart review was performed from prospectively collected database of patients with AIS who were treated with endovascular therapy from April 2010 to December 2010. Patients were divided into two groups: Group 1: included 23 patients who had initial perfusion study performed to decide endovascular management by exclusion of candidates with large matched defects, 10 males and 13 females with mean age of 68.13 (range 39–86), mean NIHSS 16.4 (range 6–26) and Group 2: included 21 patients who were treated with endovascular management without perfusion imaging screening, 10 males and 11 females with mean age 64.86 (range 34–89), mean NIHSS 15.7 (range 0–42). The primary outcome measures following the intervention were intracranial hemorrhage rate and mortality rate.

Results

Group 1: All patients had lesions in the anterior circulation. Four patients received a combination of IV and IA tPA. Two received intravenous tPA, two received intra-arterial tPA. MERCI was used in seven patients and Penumbra device was used in seven patients. Post procedure hemorrhage was 13% (n=3). The mortality rate was 4.3% (n=1). Group 2: 15 patients had lesions in the anterior circulation and six patients in posterior circulation. Four patients received a combination of IV and IA tPA. Three received intravenous tPA, six received intra-arterial tPA. MERCI was used in eight patients and Penumbra device was used in 14 patients. Post procedure hemorrhage was 30% (n=6). The mortality rate was 24% (n=5).

Conclusions

Although not a matched population, we note a trend toward a lower rate of symptomatic hemorrhage and mortality in patients who were selected based on perfusion study for endovascular therapy. Further prospective trials are warranted to evaluate role of perfusion based studies in selecting patients for endovascular management.
P-011 Preliminary results with a new volumetric-filling platinum coil, the penumbra coil 400
Authors: Woo H , Fiorella D , Han P
Published: July 2011

Purpose

The FDA has recently approved the Penumbra Coil 400 for embolization of cerebral aneurysms. It is differentiated from existing platinum coils by virtue of its 0.020″ outer diameter, which results in increased filling per coil and intrinsic softness. We report the preliminary results of peri-procedural efficacy and safety of this new coil platform at two centers.

Methods and Materials

This study is a retrospective case review of 7* consecutive patients at two centers treated with the Penumbra Coil. Adjunctive devices were used in 5 cases. The number of coils used to treat the aneurysm, the degree of occlusion and the final estimated packing density were recorded. Peri-procedural device related and clinical adverse events were recorded.

Results

There were no device-related or clinical adverse events. An average of 4.4 coils (range 2–7) were deployed per aneurysm. The average final estimated packing density was 35.7% (range 15.1–48). 5 out of 7 aneurysms were completely occluded at the end of the procedure.

Conclusions

The Penumbra Coil 400 can be successfully used to treat a wide range of aneurysm types and sizes with acceptable complete occlusion rates, final packing densities, and peri-procedural complications. It appears that fewer coils can be used to achieve these results than would be normally expected with conventional size coils. The effect on procedure time, flouro time, economics, and long term stability will require further study.
P-025 Measurement of ionizing radiation exposure over the gravid uterus during endovascular treatment of intracranial aneurysm
Authors: Cho A , Pakbaz R , Green D
Published: July 2011

Introduction

Intracranial hemorrhage during pregnacy can have catastrophic outcomes for both mother and fetus with high mortality rates (estimated 63% and 27% respectively) in untreated ruptured aneurysms. One of the most commonly expressed concerns about angiography during pregnancy is the potential risk of fetal abnormalities resulting from radiation exposure. We report direct measurement of ionizing radiation exposure over of the gravid uterus during cerebral arteriography.

Materials and methods

Dose over the gravid uterus using a TLD was measured during endovascular treatment of an intracranial aneurysm. The patient's abdomen was shielded using lead aprons place anterior and posterior, and strategies for dose reduction implemented. Pubmed search using mesh terms pregnancy, radiation dose, endovascular therapy and CT was performed for literature review.

Results

Dose measured over the gravid uterus was 11 MREM. In comparison to findings reported in the literature this level is significantly less than esposure over the uterus during CT of the abdomen to exclude appendicitis/nephrolithiasis and CT of the chest to exclude pulmonary embolism in pregnancy. The dose is similar to head CT exposure. Risk to benifit analysis for treatment of ruptured aneurysms favors treatment during pregnancy.

Conclusion

Radiation exposure to the gravid uterus and fetus during cerebral angiography and endovascular procedures are within standard radiation exposure in pregnancy guidelines and comparible with other imaging modalities used during pregnancy. Diagnostic cerebral angiography and endovascular procedures can be safely performed during pregnancy while implementing radiation dose reduction strategies.
P-029 Usefulness of 3D time-of-flight magnetic resonance angiography (MRA) and contrast-enhanced MRA following coil embolization with the Enterprise stent for cerebral aneurysm
Authors: Takayama K , Miyouchin K , Sakamoto M , Taoka T , Wada T , Nakagawa H , Kichikawa K , Kurokawa S
Published: July 2011

Purpose

The aim of this study was to determine the feasibility and usefulness of contrast-enhanced MR angiography (CE-MRA) and 3D time-of-flight (TOF) MRA for the follow-up of intracranial aneurysms treated with the Enterprise stent and detachable coils, by comparing with digital subtraction angiography (DSA).

Methods

We retrospectively analyzed five consecutive patients with five aneurysms were treated by coiling with Enterprise stent assistance and were followed-up by CE-MRA, TOF MRA, and DSA. All patients from 2 months to 6 months after endovascular treatment using Enterprise stent were included. Depictions of the internal and neck portions of the parent artery and aneurysm with TOF MRA and CE-MRA were compared with those of DSA, assumed to be the gold standard.

Results

There was an important artifact with signal loss at the level of the stent in all cases on 3D TOF MRA; it was impossible to evaluate the parent artery lumen and aneurysm neck in all cases (100%). CE-MRA demonstrated the parent artery lumen and aneurysm neck and was comparable to DSA in all cases (100%). For 3 cases of neck remnant or residual aneurysm, there was no difference in decisions regarding further therapy between CE-MRA and DSA.

Conclusion

For the follow-up after coil embolization using an Enterprise stent, evaluation with 3D TOF MRA is difficult, CE-MRA contrast-enhanced MRA is necessary.
P-030 A self-expanding wingspan stent-assisted recanalization for acute middle cerebral artery occlusion in case of failure or contraindication to intravenous thrombolysis
Authors: Sung S , Lee T
Published: July 2011

Background

Early recanalization of occluded intracranial arteries in acute ischemic stroke is one of the most important factors for better clinical outcome. Recanalization with a self-expanding Wingspan stent, which can be deployed rapidly and safely, is an option for treating acute ischemic stroke when intravenous thrombolysis has failed or is contraindicated. We present the feasibility, efficacy and safety of recanalization with a wingspan stent for acute middle cerebral artery (MCA) occlusion.

Methods

We collected 10 patients with acute MCA occlusion in whom recanalization was not achieved with a standard intravenous thrombolysis, or who were ineligible for intravenous thrombolysis or who presented after 3 h of symptom onset and the stenting could be completed within 8 h from stroke symptom onset. All 10 patients were treated with a self-expanding Wingspan stent. Recanalization results were assessed by thrombolysis in cerebral infarction (TICI) score of the target vessel after stenting. Neurological status was measured before and 7 days after stenting using the National Institutes of Health Stroke Scale (NIHSS). Procedure-related complications were assessed by a Vascular Neurologist. Functional outcome was evaluated at discharge according to the modified Rankin Scale (mRS).

Results

Successful stent deployment and recanalization were achieved in all patients (TICI 2a:1, TICI 2b:3, TICI 3:6). The patients' mean NIHSS score on admission was 12.7 points with SD of 6.3 points (range 4–21). In all 10 patients, the occlusion site were located in the 1st segment of the MCA (M1, n=7, left:2, right:5) and 2nd segment of the MCA (M2, n=3, all: right). The mean time interval from stroke symptom onset to stenting was 34.8–76.3 min. No vessel perforations or dissections occurred in any patient. None of the patients had intracranial hemorrhage visible on follow-up CT. Nine patients improved on the NIHSS at 7 days after stenting. One patient did not change the NIHSS score even though the occluded artery was completely recanalized. At 7 days after recanalization, NIHSS score of all patients was 4.4–4.7 (median 4, range 0–13). At discharge, an mRS of three was achieved in all 10 patients and an mRS of two was achieved in seven patients (70%). No further ischemic events occurred within 90 days after stenting.

Conclusions

This case series demonstrated that the self-expanding Wingspan stent can be used safely for acute MCA occlusion and can have a good clinical outcome if standard treatments are unavailable. Further, randomized trials will be needed to determine if stenting is associated with improved outcome.
E-002 Reversible cerebral vasoconstriction syndrome treated with intra-arterial vasodilator therapy: a case report
Authors: Chowdhry S , Blackham K
Published: July 2011

Background

Reversible vasoconstriction syndrome has been described as an important cause of cerebral arteriopathy and/or vasoconstriction, with non-aneurysmal SAH recently being noted as a more common presentation that previously recognized. No standardized treatment exists and serious complications such as ischemic stroke have been reported. Although distal segmental narrowing is typical, proximal vessel occlusions have been reported.

Case Report

A 43-year-old female marathon runner presented to an outside hospital following a thunderclap headache with initial negative head CT and lumbar puncture. 1 week later after worsening headache and nausea, a repeat head CT revealed right frontal intraparenchymal hematoma. A CT angiogram revealed right carotid terminus occlusion and scattered diffuse segmental narrowings. She was treated with steroids and nimodipine. Following progression of symptoms including left hemi-inattention, she was transferred to our facility and found to have a large right parietal infarct, subarachnoid hemorrhage along the right frontal cortex and multifocal moderate to severe segmental stenoses. Her NIH stroke scale was 16. Based on our experience with intra-arterial verapamil for the treatment of aneurysmal subarachnoid hemorrhage, she was taken to angiography where confirmation of multifocal proximal and distal segmental vascular narrowing was made and intra-arterial verapamil was given: 5 mg in the right internal carotid artery, 20 mg in the left internal carotid artery and 10 mg in the left vertebral artery. Immediate clinical improvement was appreciated despite modest angiographic changes. Daily transcranial Doppler studies were performed, along with induced hypertension and monitoring of central venous pressure. Systemic verapamil and high dose steroids were also administered. She returned to the angiography suite four times in the next 5 days week for clinical symptoms (left arm weakness, agitation and confusion) or elevated transcranial Doppler studies and was found to have a similar and recurrent pattern of vasospasm. She received similar intra-arterial treatment at each angiogram, again with clinical and angiographic improvement. At the time of discharge, the patient's left sided weakness and cognitive deficits had resolved but she suffered from residual left hemi-inattention.

Conclusion

We describe a patient with severe, medical-treatment refractory RCVS who demonstrated clinical and radiographic response to repeated treatment with intra-arterial vasodilator therapy.
E-009 Treatment of ruptured cerebral aneurysms is increasingly occurring in high volume centers in the USA
Authors: Leake C , Brinjikji W , Kallmes D , Cloft H
Published: July 2011

Purpose

Although there is no formal system for regionalization of care for subarachnoid hemorrhage, evidence of better outcomes at higher volume centers might be expected to result in more of these patients being referred to high volume centers. The purpose of this study was to evaluate the US National Inpatient Sample (NIS) from 2001 to 2008 for trends in patient admissions for treatment of ruptured aneurysms at high and low volume centers.

Methods

We evaluated the numbers of ruptured aneurysms treated with clipping and coiling annually at low (≤20 patients/year) and high volume (>20 patients/year) centers, and also counted the number of high and low volume centers for each treatment. Hospitalizations for clipping or coiling of ruptured aneurysms were identified by cross-matching International Classification of Disease Codes for diagnosis of ruptured aneurysm (430.0) with procedure codes for clipping (39.51) or coiling (39.52, 39.79, or 39.72) of cerebral aneurysms.

Results

(Abstract E-009 figure 1) In 2001, 31% (435/1392) of patients clipped and 0% (0/122) of patients coiled were treated at high volume centers, whereas in 2008 these numbers increased to 62% (627/1016) of patients clipped and 68% (917/1351) of patients coiled, respectively. For clipping, the number of low volume centers significantly declined from 177 centers in 2001 to 85 centers in 2008, while the number of high volume centers has remained constant at 13 to 15. For coiling procedures, the number of low volume centers decreased from 62 centers in 2001 to 54 centers in 2008, while the number of high volume centers substantially increased from 0 centers in 2001 to 16 centers in 2005 and remained constant thereafter.

Abstract E-009 Figure 1

Conclusion

Treatment of ruptured cerebral aneurysms is increasingly occurring in high volume centers in the USA. This is a favorable trend in that better outcomes are associated with care for these patients at a high volume center.
E-011 Merci retrievers as access adjuncts for reperfusion catheters: the grappling hook technique
Authors: Hui F , Hussain M , Spiotta A , Bhalla T , Toth G , Moskowitz S , Elgabaly M , Sivapatham T , Jafari N , Rasmussen P
Published: July 2011

Objective and Importance

Expeditious and stable access in the setting of acute ischemic stroke is foundational to mechanical revascularization of large vessel occlusions of the cerebral vasculature, particular when using an aspiration based system. Proximal vascular tortuousity and unfavorable anatomic variability may impede vascular access necessary for revascularization. In particular, the ophthalmic segment often proves difficult for large caliber aspiration catheters to navigate. We describe an approach using the Merci Retriever system as an adjunct to gain stable catheter access for aspiration.

Clinical Presentations

Three patients presenting with acute ischemic stroke were treated via mechanical thrombectomy using the Penumbra 054 system. However, due to anatomical configurations, access to the M1 segment was challenging, with difficulty traversing the ophthalmic segment of the internal carotid artery ipsilateral to the respective M1 segment occlusion.

Intervention

Aspiration catheter access into the distal middle cerebral artery was achieved via advancement of an 18L microcatheter followed by deployment of an appropriately sized Merci Retriever into the M1 segment. Gentle tension on the Retriever was applied, altering the angle at which the Aspiration catheter navigated the ophthalmic segment, affording accelerated access past the ophthalmic artery origin and into the ipsilateral M1 segment and clot. Retraction of the retriever into the 18L was followed by removal of the 18L in each case, which was in turn followed by aspiration using the Penumbra Aspiration catheter.

Conclusion

Time is of the essence in treating acute ischemic stroke, and, upon occasion, tortuous proximal anatomy may impede access to the occluded vessel. By making use of the apposition of a Merci retriever against the wall of a vessel, increased tension and straightening along the core wire changes the angle at which the large profile catheter makes with the vessel. As such, in unfavorable ophthalmic segment anatomy, this technique may be employed to advance an aspiration catheter to treat the offending embolus in the setting of an acute ischemic stroke.
E-013 Comparison of initial results following dual aneurysm embolization with the new penumbra coil 400 and 10-size coils in a single patient treated by the same operator
Authors: Gaughen J
Published: July 2011

Purpose

The recently available Penumbra Coil 400 has 400% the volume per unit length of a 10-size coil due to its 0.020″ primary diameter, double that of conventional 10-coils. The Penumbra Coil 400 also purports to be softer than an equivalent 10-coil due to the larger primary diameter. This case report investigates these claims through two aneurysms treated in the same patient with two different coil systems.

Methods and Materials

A 53-year-old female presented with acute onset left 3rd nerve palsy. Her history was notable for clipping of a right posterior communicating artery aneurysm 18 years prior. She was found to have a 7.4×5.0×5.0 mm (97 mm3) basilar artery bifurcation aneurysm and a 12.7×11.2×10.8 mm (804 mm3) anterior communicating artery (Acomm) aneurysm. The basilartip aneurysm was accessed with an Eschelon-10 microcatheter (Covidien, Dublin, Ireland) and embolized with five GDC-10 coils (Stryker, Kalamazoo, Michigan, USA):5 mm×15 cm, 4 mm×6 cm, 3 mm×8 cm, 2 mm×6 cm and 2 mm×4 cm. The coiling endpoint was catheter kick-out. 7 days later, the Acomm aneurysm was accessed with a PX400 microcatheter (Penumbra, Inc., Alameda, California, USA) and embolized with eight Penumbra coils: 10 mm ×40 cm, 8 mm×20 cm and 5 mm×10 cm complex standard, 4 mm×8 cm and 3 mm×10 cm complex soft, 3 mm×6 cm, 2 mm×3 cm and 2 mm×2 cm helical extra soft. The coiling endpoint was catheter kickout.

Results

Procedure results for both aneurysms are shown below. There were no technical or clinical complications with either procedure.

Conclusions

The Penumbra Coil 400 filled a large aneurysm to adequate packing density in about the same overall time and use of fluoroscopy as a smaller aneurysm treated with 10-size coils, despite the Penumbra-treated aneurysm being 8.3 times larger by volume. Follow-up will be required to assess the durability of occlusion in both aneurysms.

Abstract E-013 Table 1Basilar tip aneurysmAcomm aneurysmAneurysm volume97 mm3804 mm3Coil type usedGDC-10Penumbra coil 400# of coils58Total coil length39 cm99 cmFinal packing density22.0%(Angiosuite iPhone App)24.9%(Angiosuite iPhone App)Total fluoro time (min)34.5 min31.3 minTotal procedure time (min)101 min118 min
E-015 Mechanical and chemical angioplasty for sah induced cerebral vasospasm: experience at the university of Michigan 1997–2005
Authors: Pandey A , Bunney A , Singh R , Thompson B , Chaudhary N , Fletcher J , Rajajee K , Gemmete J
Published: July 2011

Objective

To evaluate the safety and efficacy of chemical and mechanical angioplasty in the treatment of medically refractory cerebral vasospasm toward the goal of identifying factors predicting clinical outcome.

Methods

All patients undergoing endovascular management of medically refractory cerebral vasospasm at the University of Michigan between 1997 and 2005 were included. Clinical and angiographic data were collected retrospectively with the review of clinical charts as well radiographic images once institutional review board approval was gained.

Results

28 patients underwent mechanical/chemical angioplasty during this time period. Demographic data included: mean age 51.8 years, 21% male, 79% female, and 89% Caucasians. Anterior circulation aneurysm comprised 52% of this patient population and 80% of the patients presented with a Hunt Hess III/IV grade SAH while 96% had a Fisher IV bleeding pattern. The mean aneurismal neck size was 3.7 mm while the dome size was 7.4 mm. 59% of the patient population had undergone microsurgery for aneurismal protection as opposed to endovascular treatment. 56% of the patients were tobacco users and 39% had a history of hypertension. 78% of the patients had presented 5–12 days post SAH. There were no vessel dissections, ruptures, or thrombosis associated with the mechanical procedure. Only 38% of patients required angioplasty involving the posterior circulation vasculature. Modified Rankin score improved from the time of vasospasm to the time of discharge with statistical significance (14% independent at time of symptoms as opposed to 53% independent at time of discharge).

Conclusion

SAH associated cerebral vasospasm leads to significant morbidity and mortality. Mechanical and chemical angioplasty are safe and effective methods of preventing DIND associated with medically refractory cerebral vasospasm.