[Show abstract][Hide abstract] ABSTRACT: The CCQM-K82 comparison was designed to evaluate the degrees of equivalence of NMI capabilities for methane in air primary reference mixtures in the range (1800-2200) nmol mol-1. The balance gas for the standards was either scrubbed dry real air or synthetic air.
CH4 in air standards have been produced by a number of laboratories for many years, with more recent developments focused on standards at atmospheric measurement concentrations and aimed at obtaining agreement between independently produced standards. A comparison of the differences in primary gas standards for methane in air was previously performed in 2003 (CCQM-P41 Greenhouse gases. 1 and 2) with a standard deviation of results around the reference value of 30 nmol mol-1 and 10 nmol mol-1 for a more limited set of standards. This can be contrasted with the level of agreement required from field laboratories routinely measuring atmospheric methane levels, set by Data Quality Objectives (DQO) established by the World Meteorological Organization (WMO) to reflect the scientifically desirable level of compatibility for CH4 measurements at the global scale, currently set at 2 nmol mol-1 (1 sigma).
The measurements of this key comparison took place from May 2012 to June 2012.
Eight laboratories took part in this comparison coordinated by the BIPM and NIST. Key comparison reference values were calculated based on Cavity Ring Down Spectroscopy Measurements performed at the BIPM, combined with participant’s gravimetric values to identify a consistent set of standards. Regression analysis allowed predicted values for each standard to be calculated which acted as the KCRVs. In this comparison reported standard uncertainties by participants ranged from 0.50 nmol/mol to 2.4 nmol/mol and the uncertainties of individual KCRVs ranged from 0.68 nmol/mol to 0.71 nmol/mol.
The standard deviation of the ensemble of standards about the KCRV value was 1.70 nmol/mol. This represents a greater than tenfold improvement in the level of compatibility of methane in air standards compared to that demonstrated in 2003. Further improvements in the compatibility of standards will require improved methods and uncertainties for the measurement of trace level methane in balance gases.
[Show abstract][Hide abstract] ABSTRACT: Little is known about high-signal lesions in magnetic resonance diffusion-weighted imaging (DWI [+]) after stenting for intracranial atherosclerotic stenosis. This study aimed to evaluate the incidence, distribution, risk factors, and clinical implications of DWI (+) after intracranial stenting.
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND AND PURPOSECoil packing density (PD) can be calculated via a formula (PDF) or software (PDS). Two types of PD can be different from each other for same aneurysm. This study aimed to evaluate the interobserver agreement and relationships between the 2 types of PD relative to aneurysm size.METHODS
Consecutive 420 saccular aneurysms were treated with coiling. PD (PDF, [coil volume]/[volume calculated by formula] and PDS, [coil volume]/[volume measured by software]) was calculated and prospectively recorded. Interobserver agreement was evaluated between PDF and PDS. Additionally, the relationships between PDF and PDS relative to aneurysm size were subsequently analyzed.RESULTSInterobserver agreement for PDF and PDS was excellent (Intraclass correlation coefficient, PDF; 0.967 and PDS; 0.998). The ratio of PDF and PDS was greater for smaller aneurysms and converged toward 1.0 as the maximum dimension (DM) of aneurysm increased. Compared with PDS, PDF was overestimated by a mean of 28% for DM < 5 mm, by 17% for 5 mm ≤ DM < 10 mm, and by 9% for DM ≥ 10 mm (P < 0.01).CONCLUSIONS
Interobserver agreement for PDF and PDS was excellent. However, PDF was overestimated in smaller aneurysms and converged to PDS as aneurysm size increased.
Journal of neuroimaging: official journal of the American Society of Neuroimaging 07/2014; · 3.36 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This study aimed to evaluate clinical and angiographic outcomes of Y-configuration double-stent-assisted (Y-stent) coiling using two closed-cell stents for wide-necked basilar tip aneurysm (BTA).
[Show abstract][Hide abstract] ABSTRACT: Overwide and undertall small intracranial aneurysms remain a challenge for coil embolization. The purpose of this study is to evaluate the feasibility and results of intrasaccular double microcatheter endovascular coil embolization of overwide and undertall small intracranial aneurysms.
Small (<7 mm), overwide (dome-to-neck ratio [DNR] ≤1.2), and undertall (ASPECT ratio ≤1.2) aneurysms which were treated with double microcatheter technique were selected. For the double microcatheter technique, two microcatheters were selected simultaneously into the aneurysm sac and coil insertion was performed alternatingly. The initial results, ASPECT, DNR ratios, complications, and follow-up results were assessed.
Twenty small (mean, 3.8 mm), overwide (mean DNR, 1.1), and undertall (mean ASPECT, 1.0) aneurysms were treated with the double microcatheter technique. Overall, complete or near complete occlusion was achieved in 19/20 cases. This was achieved with only the double microcatheter technique in 16/20 cases (ASPECT mean, 1.0; DNR mean, 1.1). Adjuvant balloon remodeling was performed in 4/20 cases (ASPECT mean, 0.8; DNR mean, 1.1). The ASPECT ratio was significantly lower in the adjuvant balloon remodeling cases (p = 0.027). Coiling failed in one patient with both DNR and ASPECT ratio <1.0. Overall, one patient developed a focal visual field defect after the procedure. No other patients developed neurologically significant complications.
Double microcatheter technique may be a safe and effective method for the treatment of overwide and undertall small intracranial aneurysms.
[Show abstract][Hide abstract] ABSTRACT: The purpose of this study was to compare clinical outcomes and treatment-related complications between coiling and clipping for ruptured distal anterior cerebral artery (DACA) aneurysms.
Eighty-four consecutive patients (M:F = 36:48; mean 53.8 years) with ruptured DACA aneurysms were treated by either clipping (n = 46, 54.8%) or coiling (n = 38, 45.2%). The clinical outcomes and procedure-related complications were evaluated and compared between the two groups.
Procedure-related complications tend to occur more frequently in the clipping (n = 6, 13.0%) than coiling group (n = 1, 2.6%) (P = .121). At discharge, 51 patients (60.7%) had favorable outcomes (Glasgow outcome scale [GOS], 4 or 5). There was no significant difference between the two groups in favorable outcome (63.2% vs. 58.7%; P = .677). Hunt and Hess (HH) grade (P < .001; 95% CI, 3.354-29.609) and treatment modality (P = .044; 95% CI, 1.039-16.325) were independent risk factors for poor outcome (GOS, 1-3).
Coiling was more favorable to clipping in clinical outcomes and incidence of treatment-related complications for ruptured DACA aneurysms.
Journal of neuroimaging: official journal of the American Society of Neuroimaging 12/2013; · 3.36 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Coil embolization of wide-necked or fusiform vertebrobasilar aneurysms is challenging and tends to involve frequent recanalization.
The aim of our study was to evaluate complications and mid-term outcomes of complex vertebrobasilar artery aneurysms after stent-assisted coiling with various techniques.
We retrospectively evaluated 28 cases of unruptured vertebrobasilar aneurysm treated by stent-assisted coiling.
Forty-four of the 45 stents placed in 28 patients were deployed at the desired location (97.8 %). Single stent-assisted coiling was performed in 14 aneurysms, a stent-within-a-stent (SWS) technique was used in 12 aneurysms, and Y-stent-assisted coiling was employed in four basilar tip aneurysms. Two basilar tip aneurysms treated by single stent-assisted coiling recurred and were retreated by SWS and Y-stent-assisted coiling. Complete embolization was achieved in 19 aneurysms (67.8 %), and remnant neck persisted in eight aneurysms (28.6 %) and remnant aneurysm was noted in one aneurysm (3.6 %). Permanent neurologic deficit (Modified Rankin Scale 1 and 4) was noted in two patients (7.1 %). Angiographic follow-up (mean follow-up period: 20.8 months) was performed in 20 patients. Major recanalization occurred in two basilar tip aneurysms (10 %) and minor compaction was noted in one superior cerebellar artery aneurysm. The remaining 17 aneurysms were stable or improved (85 %).
Complex vertebrobasilar aneurysm embolization with stent-assisted techniques was effective and feasible as a method for reducing recanalization during midterm angiographic follow-up. Large and wide-necked basilar tip aneurysms showed frequent major recanalization, and compact packing with single or Y-stent-assisted coiling is needed to prevent recanalization even if coiling will be done without stenting.
[Show abstract][Hide abstract] ABSTRACT: Widespread use of thrombolytic treatments, along with improved chances of survival after an initial ischemic stroke, increases the possibility of repeated thrombolysis. There are few reports, however, regarding repeated thrombolysis in patients who have suffered acute ischemic stroke. We explored the number and outcome of patients with repeated thrombolytic therapy in the era of multimodal thrombolytic treatments.
We investigated patients with acute ischemic stroke who had received thrombolytic treatments for a period of 10 years. Number of thrombolysis was determined in each patient. Recanalization was defined as Thrombolysis in Cerebral Infarction grading ≥2a. Symptomatic hemorrhagic transformation was defined as any increase in the National Institutes of Health Stroke Scale score that could be attributed to intracerebral hemorrhage. A good outcome was defined as a modified Rankin scale score ≤2.
Of the 437 patients who received thrombolytic treatments, only 7 underwent repeated thrombolysis (1.6%). The median age at the time of repeated thrombolytic therapy was 71 years old; 4 of the patients were female. All patients had 1 or more potential sources of cardiac embolism. Recanalization was achieved in all patients, in both the first and the second thrombolysis. No symptomatic intracranial hemorrhage occurred after repeated thrombolytic treatments. Five patients (71.4%) showed good outcomes at 3 months.
Repeated thrombolysis for recurrent acute ischemic stroke appears to be safe and feasible. Among patients who experience recurrent acute ischemic stroke, thrombolytic therapy could be considered even if the patient has had previous thrombolytic treatments.
[Show abstract][Hide abstract] ABSTRACT: A new double-lumen balloon catheter was being developed for the treatment of cerebral aneurysms. The purpose of this study is to report our initial experience of a double-lumen balloon catheter for the treatment of wide-necked aneurysms.
Seventeen patients (mean age, 63 years; range, 45-80 years) with wide-necked, with or without a branch-incorporated aneurysms, (10 ruptured and 9 unruptured) were treated with balloon-assisted coil embolization using a double-lumen balloon catheter (Scepter C™ or Scepter XC™) for 7 months after being introduced to our country. Locations of the aneurysms were posterior communicating artery (n = 7), anterior communicating artery or A2 (n = 7), middle cerebral artery (MCA) bifurcation (n = 3), basilar artery tip (n = 1) and anterior choroidal artery (n = 1). The initial clinical and angiographic outcomes were retrospectively evaluated.
Coil embolization was successfully completed in all 19 aneurysms, resulting in complete occlusions (n = 18) or residual neck (n = 1). In one procedure, a thrombus formation was detected at the neck portion of the ruptured MCA bifurcation aneurysm near to the end of the procedure. It was completely resolved with an intra-arterial infusion of Glycoprotein IIb/IIIa inhibitor (Tirofiban, 1.0 mg) without any clinical sequela. There were no treatment-related events in the remaining 18 aneurysms. At discharge, functional neurological state improved in 11 patients (10 patients with ruptured aneurysm and 1 with unruptured aneurysm presenting with mass symptoms) and 6 patients with unruptured aneurysms had no newly developed symptoms.
In this preliminary case series, the newly developed double-lumen Scepter balloon appears to be a safe and convenient device for coil embolization of wide-necked aneurysms.
Korean journal of radiology: official journal of the Korean Radiological Society 09/2013; 14(5):832-40. · 1.32 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The purpose of this study is to present our preliminary experience of the temporary endovascular bypass (TEB) technique using an Enterprise stent for recanalization of acute intracranial artery (IA) occlusion.
Patients treated by TEB were enrolled in this retrospective study from January 2009 to May 2010. All the procedures consist of temporary partial deployment and subsequent retrieval of Enterprise stent, supplemented by intra-arterial infusion of urokinase (UK) and/or tirofiban. According to the thrombolysis in cerebral infarction (TICI) classification, recanalization was evaluated with initial and postprocedural angiography. Safety was evaluated related to the procedure and clinical outcomes were assessed by National Institute of Health Stroke Scale (NIHSS) score at discharge and modified Rankin scale (mRS) score at 3 months.
Eleven patients (median NIHSS 12.8, mean age 61.6 years, male: female = 8:3) with acute IA occlusion were treated with TEB. All the patients presented with TICI 0, and the occluded vessel was the middle cerebral artery (n=7), the basilar artery (n=1), and the distal ICA occlusion (n = 3). IV infusion of tissue plasminogen activator (tPA) was done in 4 patients and mechanical thrombolysis with intra-arterial UK was performed in 9. Recanalization was achieved in 73% (8 patients; TICI ≥ 2). There were no procedure-related complications except for two asymptomatic intracranial hemorrhages. Improvement (≥ 4 points on the NIHSS) and good outcome (mRS ≤2) after 90 days was shown in six patients (55%). One patient died 6 days after procedure.
TEB may be a valuable treatment option in acute thromboembolic IA occlusion without stent implantation.
[Show abstract][Hide abstract] ABSTRACT: Posterior cerebral artery (PCA) aneurysms are rare and often challenging to manage. Since Drake's historical report regarding PCA aneurysms, there has been limited additional information on recent advancements in either microsurgical or endovascular tools. We report a series of 25 consecutive cases and attempt to extrapolate useful information for managing PCA aneurysms.
A total of 25 cases of PCA aneurysm that were treated either by microsurgical or endovascular methods were selected and retrospectively reviewed. The clinical data, radiographic findings, and outcomes associated with the treatment modality were analysed.
The case series included 13 women and 12 men with a mean age of 52 years, ranging from 11 to 75 years. Fourteen aneurysms were ruptured, 7 aneurysms caused a direct mass effect, and the remaining 4 aneurysms were found incidentally. Most aneurysms were located in the P1 through P2A segment of the PCA (19 aneurysms, 76%). Seven aneurysms (28%) were large-giant in size (>20mm), 4 of which had a thrombosed sac. Microsurgical treatment was the primary treatment in 15 aneurysms, including 9 successful direct clip ligations, 3 aneurysms that were surgically trapped without a bypass, and 2 wrapped aneurysms. One giant thrombosed aneurysm was incompletely clipped; subsequently, the large remnant was coil-embolised. Endovascular coil embolisation was performed for 6 aneurysms, stent-assisted coil embolisation was performed for 2 aneurysms, and 2 aneurysms were treated by endovascular occlusion of the parent artery. Permanent deficits acquired after treatment included limb weakness, palsy of the third cranial nerve, and hemianopsia in 5 cases (20%). There was no mortality. Overall, 22 patients (88%) showed favourable clinical outcomes according to the modified Rankin Scale Score (≤2) at the mean clinical follow-up period of 43.2 months (range: 2-130 months).
The present case series suggests that treating PCA aneurysms with microsurgical or endovascular options can achieve a comparable outcome when a judicious decision is made. Endovascular treatment had excellent anatomical and clinical outcomes for non-mass compressing, non-giant, saccular aneurysms. Given the propensity for the large-giant, dysplastic nature of PCA aneurysms to develop in younger patients, microsurgical competence should be maintained. Along with careful evaluation of the anatomic collaterals over the PCA territory, therapeutic parent artery sacrifice may be an appropriate option without adding bypass.
Clinical neurology and neurosurgery 07/2013; · 1.30 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The purpose of this study was to retrospectively evaluate and compare the incidence of diffusion-weighted image (DWI) lesions between the Guglielmi detachable coil (GDC) and the Target coil for treating unruptured intracranial aneurysm.
From 2010 to 2011, consecutive 222 patients with an intracranial aneurysm underwent coil embolization. Inclusion criterias were : 1) unruptured intracranial aneurysm, 2) one or more GDC or Target coils used with or without other coils, 3) DWI examination within 24 hours after coiling, and 4) coiling performed without a balloon or stent.
Ninety patients (92 cases) met the inclusion criteria. DWI lesions were detected in 55 (61.1%) of 90 patients. In the GDC group (n=44), DWI lesions were detected in 31 (70.5%). The average number of DWI lesions was 5.0±8.7 (mean±SD; range, 1-40) in aneurysm-related territory. In the Target coil group (n=48), DWI lesions were detected in 24 (50.0%). The number of DWI lesion was 2.1±5.4 (range, 1-32) in aneurysm-related territory. There was no significant correlation between a number of coils and DWI lesions. No significant differences were also observed in the number of DWI lesions in each group.
The GDC and Target coils, which have an electrolytic detachable system, showed no differences in the incidence of DWI lesion.
Journal of Korean Neurosurgical Society 07/2013; 54(1):19-24. · 0.56 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The diagnosis and treatment of unruptured paraclinoid aneurysms has been increasing with the recent advent of diagnostic tools and less invasive endovascular therapeutic options. Considering the low incidence of rupture, investigation of the characteristics of ruptured paraclinoid aneurysm is important to predict rupture risk of the paraclinoid aneurysms. The objective of this study is to evaluate probable factors for rupture by analyzing the characteristics of ruptured paraclinoid aneurysms.
A total of 2,276 aneurysms (1,419 ruptured and 857 unruptured) were diagnosed and treated endovascularly or microsurgically between 2001 and 2011. Among them, 265 were paraclinoid aneurysms, of which 37 were ruptured. Removing 12 blister-like aneurysms, 25 ruptured and 228 unruptured saccular aneurysms were included and the medical records and radiological images were retrospectively analyzed.
Of 25 aneurysms, 16 (64.0 %) were located in the superior direction. Five were inferior located lesions (20 %) and four were medially located lesions (16.0 %). Laterally located lesions were not found. The mean size of aneurysms was 9.4 ± 5.6 mm. Ten aneurysms (40.0 %) were ≥ 10 mm in size. Thirteen aneurysms (52.0 %) were lobulated. The superiorly located aneurysms were larger than the other aneurysms (10.3 ± 5.8 mm vs. 7.7 ± 4.9 mm) and more frequently lobulated (ten of 16 vs. three of nine). In a comparative analysis, the ruptured aneurysms were located more in the superior direction compared with unruptured aneurysms (64 vs. 23.2 %, p < 0.0001). Large aneurysms (36.0 vs. 7.9 %, p < 0.0001), longer fundus diameter (mean 9.4 ± 5.6 vs. 4.8 ± 3.3 mm, p = 0.001), dome-to-neck ratio (mean 1.8 ± 0.9 vs. 1.2 ± 0.5, p < 0.0001), and lobulated shape aneurysms were more likely to be ruptured aneurysms (13 of 25 ruptured aneurysms, 52.0 %, p = 0.001).
Rupture risk of the paraclinoid aneurysm is very low. However, superiorly located paraclinoid aneurysms appear more likely to rupture than other locations. Angiographically, more conservative indication for the treatment of paraclinoid aneurysm should be recommended except for superior located lesions.
[Show abstract][Hide abstract] ABSTRACT: The aim of this study is to assess the relationship between the venous angioarchitectural features and the clinical course of intracranial dural arteriovenous shunt (DAVS) with cortical venous reflux (CVR).
With institutional review board approval, 41 patients (M:F = 24:17; median age, 52 years (range, 1-72 years), median follow-up; 1.5 years; partial treatment, n = 36) with persistent CVR were included. We evaluated the initial presentation and the incidence of annual morbidity (hemorrhage or new/worsened nonhemorrhagic neurological deficit (NHND)) according to the venous angiographic patterns-isolated venous sinus, occlusion of the draining sinus, direct pial venous drainage, pseudophlebitic pattern, venous ectasia, brisk venous drainage, and length of pial vein reflux-on digital subtraction angiography. Cox regression was performed to identify independent factors for clinical course.
During 111.9 patient-years of follow-up, the overall annual morbidity rate was 11.6 % (mortality; n = 3, rate; 2.6 %/year). Hemorrhage occurred in five patients (12.2 %, rate; 4.5 %/year) and new/worsened NHND occurred in eight patients (19.5 %, rate; 7.2 %/year). Patients with isolated venous sinus, direct pial venous drainage, and pseudophlebitic pattern were associated with initial aggressive presentation. Venous ectasia was associated with initial hemorrhagic presentation. Brisk venous drainage was associated with initial benign presentation. Patients with isolated venous sinus showed a poor clinical course with a higher annual incidence of hemorrhage or new/worsened NHND (91.2 %/year vs 9.2 %/year; hazard ratio, 6.681; p = 0.027).
Venous angioarchitectural features may be predictive of the clinical course of DAVSs. DAVS patients with isolated venous sinus may be especially at high risk for future aggressive clinical course.
[Show abstract][Hide abstract] ABSTRACT: Object Carotid artery stenting (CAS) can be an alternative option for carotid endarterectomy in the prevention of ischemic stroke caused by carotid artery stenosis. The purpose of this study was to evaluate the influence of stent design on the incidence of procedural and postprocedural embolism associated with CAS treatment. Methods Ninety-six symptomatic and asymptomatic patients, consisting of 79 males and 17 females, with moderate to severe carotid artery stenosis and a mean age of 69.0 years were treated with CAS. The stent type (48 closed-cell and 48 open-cell stents) was randomly allocated before the procedure. Imaging, procedural, and clinical outcomes were assessed and compared. The symptomatic subgroup (76 patients) was also analyzed to determine the influence of stent design on outcome. Results New lesions on postprocedural diffusion-weighted imaging (DWI) were significantly more frequent in the open-cell than in the closed-cell stent group (24 vs 12, respectively; p = 0.020). The 30-day clinical outcome was not different between the 2 stent groups. In the symptomatic patient group, stent design (p = 0.017, OR 4.173) and recent smoking history (p = 0.036, OR 4.755) were strong risk factors for new lesions on postprocedural DWI. Conclusions Stent design may have an influence on the risk of new embolism, and selecting the appropriate stent may improve outcome.
Journal of Neurosurgery 06/2013; · 3.15 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This paper provides useful and important information in gas metrology especially where high-precision gas mixtures are essential. Buoyancy effects due to cylinder expansion are taken into account as a source of uncertainty in weighing for the preparation of primary or standard gas mixtures by gravimetric methods. Potential effects of cylinder construction materials, nominal volumetric capacity and filling gas species on cylinder volume during the preparation of primary standard gas mixtures remain unknown in the current literature. It is also difficult to find experimental evidence to demonstrate the theory that cylinder expansion upon pressurization is linear. We therefore devised an indirect measurement method to measure apparent volume changes and ultimately estimate changes in the volume of highly pressurized cylinders. We found that changes in the volumes of some gas cylinders varied significantly with construction material and nominal volumetric capacity. The relative volume changes for aluminium alloy cylinders were about 30% higher than those for manganese steel cylinders regardless of the nominal volumetric capacity and the filling gas species. We also provide experimental evidence verifying that changes in cylinder volume follow nearly linear patterns within the pressure range from 12 MPa to 0.1 MPa. Our estimate for the volume expansion of an aluminium alloy cylinder of 5 dm3 capacity with a pressure difference of 15 MPa is (15 ± 2) cm3. The reported value of about 20 cm3 in ISO 6142 : 2001 would be regarded as a rough estimate.
[Show abstract][Hide abstract] ABSTRACT: Object The purpose of this study was to evaluate the incidence, radiographic findings, relationship between presenting symptoms for treatment and drainage pattern, and treatment outcomes of hypoglossal canal dural arteriovenous fistula (HC-dAVF). Methods During a 16-year period, 238 patients underwent endovascular treatment for cranial dAVF at a single center. The incidence, radiographic findings, relationship between presenting symptoms for treatment and drainage pattern, and treatment outcomes of HC-dAVF were retrospectively evaluated. Results The incidence of HC-dAVF was 4.2% (n = 10). Initial symptoms were tinnitus with headache (n = 6), tinnitus only (n = 1), ocular symptoms (n = 1), otalgia (n = 1), and congestive myelopathy (n = 1). Presenting symptoms requiring treatment included ocular symptoms (n = 4), hypoglossal nerve palsy (n = 4), aggravation of myelopathy (n = 1), and aggravation of tinnitus with headache (n = 1). While the affected HC was widened in 4 of 10 patients, hypersignal intensity on source images was conspicuous in all 7 patients who underwent MR angiography (MRA). All ocular symptoms and congestive myelopathy were associated with predominant drainage to superior ophthalmic or perimedullary veins due to antegrade drainage restriction. All patients who underwent transvenous coil embolization (n = 8) or transarterial N-butyl cyanoacrylate (NBCA) embolization (n = 1) improved without recurrence. One patient who underwent transarterial particle embolization had a recurrence 12 months posttreatment and was retreated with transvenous embolization. Conclusions The incidence of HC-dAVF was 4.2% of all cranial dAVF patients who underwent endovascular treatment. Source images of MRA helped to accurately diagnose HC-dAVF. More aggressive symptoms may develop as a result of a change in the predominant drainage route due to the development of venous stenosis or obstruction over time. Transvenous coil embolization appears to be the first treatment of choice.
Journal of Neurosurgery 05/2013; · 3.15 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND:: Controversy remains about the optimal treatment for blood blister-like aneurysms (BBA). OBJECTIVE:: To evaluate clinical and angiographic outcomes after reconstructive treatment for BBA using stent and coil. METHODS:: Thirty-four patients (M:F=6:28; mean age, 47.3 years) with ruptured BBAs underwent reconstructive treatment using stent and coil. Post-treatment courses and outcomes were retrospectively evaluated. RESULTS:: Initial treatments were 2 or more overlapping stents with or without coiling (n=28) and single stent with coiling (n=6). Three BBAs re-bled on days 9, 11, and 15 post-treatment, resulting in 1 death. Except for 3 patients who died early, 31 patients were followed-up for 7 - 80 months (median, 32 months). One patient recovered completely but died from complications of systemic lupus erythematosus at 25 months. Of the remaining 30 patients, 25 had favorable (modified Rankin scale, 0-2) and 5 unfavorable outcomes. Angiographic follow-up was available in the 32 BBAs. Eight (25.0%) recurred, all within 5 weeks. In multiple stents group (n=26), 22 BBAs showed improvement or complete healing, but 4 (15.4%, 2 rebleedings) had recurrence. In single stent with coiling group (n=6), 2 BBAs were stable but 4 (66.7%, 1 rebleeding) had recurrence. Single stent with coiling and Hunt & Hess grade ≥ 4 were two independent risk factors for recurrence (p < 0.05). CONCLUSION:: Reconstructive treatment using stent and coil appears a viable option for BBA. Single stent with coiling and Hunt & Hess grade ≥ 4 were two independent risk factors for recurrence. Follow-up angiography should be considered mandatory soon after treatment.
[Show abstract][Hide abstract] ABSTRACT: To evaluate the feasibility and clinical and angiographic outcomes of stent-assisted embolization for complex middle cerebral artery (MCA) aneurysms.
The records of 23 consecutive patients with 24 MCA aneurysms, who underwent stent-assisted embolization of the aneurysm, were retrospectively evaluated.
Fifteen aneurysms were treated with one stent and 8 were treated using more than two stents (5 a stent-within-a-stent, 1 triple stents, and two Y-stent). Angiographically, complete or near complete occlusion was achieved in 15 aneurysms (65.2%), residual neck in five (21.7%), and residual aneurysm in three (13.1%). Five aneurysms demonstrated thrombosis within the stent during the procedure and hospitalization, and were resolved by intraarterial and intravenous Tirofiban injection. Symptomatic thromboembolic complications were developed in five patients and permanent deficits demonstrated in two patients with modified Rankin Scale 1 and 2, respectively. Treatment-related permanent morbidity and mortality rates were 8.3% and 0% with relatively high complication rate. Angiographic follow-up was available in 17 aneurysms at 6-31 months (mean, 13.2 months) and showed stable or improved in 15 (88.2%) and major and minor recurrence in one, respectively.
Complex MCA aneurysms could be treated by stent-assisted coiling and showed lower recanalization rate during mid-term follow-up by effective flow diversion due to various stent-assisted techniques. Our results warrant further study with a longer follow-up period in a larger sample.
Journal of Korean Neurosurgical Society 05/2013; 53(5):274-80. · 0.56 Impact Factor