PurposeThis study is an overview of the clinical and radiologic outcomes of endovascular coil embolization for cerebral aneurysm in patients aged 40 years and younger.Materials and MethodsBetween January 2008 and June 2011, 218 aneurysms were treated using endovascular coil embolization and followed up with cerebral angiography at least six months later. Twenty-one aneurysms occurred in patients aged 40 years and younger, while 197 occurred in 179 patients older than 40 years. The clinical and radiologic results were retrospectively analyzed and compared between the two groups using the modified Rankin scale scores and the modified Raymond scale.ResultsFollow-up cerebral angiography revealed two (9.5%) major and two (9.5%) minor recanalized aneurysms in patients aged 40 years and younger, and six (3.0%) major and 35 (17.7%) minor recanalized aneurysms in patients older than 40 years. However, the differences between the groups were not statistically significant. The preoperative and postoperative mean modified Rankin scale scores at time for follow-up angiography were 1.14 and 0.19 respectively for patients aged 40 years and younger, and 1.30 and 0.30 respectively for patients older than 40 years.ConclusionThe younger patients had clinically favorable outcomes with tolerable angiographic follow-up results. More regular and long-term imaging follow-up is required for younger patients due to their longer life expectancy.

We investigate the potentials and limitations of computational fluid dynamics (CFD) analysis of patient specific models from 3D angiographies. There are many technical problems in acquisition of proper vascular models, in pre-processing for making 2D surface and 3D volume meshes and also in post-processing steps for display the CFD analysis. We hope that our study could serves as a technical reference to validating other tools and CFD results.

Mechanical thrombectomy (MT) alone in cases of large-vessel acute ischemic stroke (AIS) with a concomitant subdural hematoma (SDH) seems feasible and safe, but there's still a lack of evidence in the clinical literature. We report three cases of AIS with SDH, of which MT was performed with successful recanalization and no major changes in SDH: two elderly men with acute traumatic SDH and one man with incidental chronic SDH. (1) A 67-year-old man with acute traumatic SDH in the right side developed right middle cerebral artery (MCA) stroke, (2) a 72-year-old man with chronic SDH in the left side developed right MCA stroke, and (3) a 76-year-old-man with acute traumatic SDH in the right side developed top-of-basilar artery syndrome. As for AIS patients with a SDH, MT may be the only feasible and safe treatment option.

In February 2013, results of two key clinical trials assessing clinical efficacy of endovascular management in acute ischemic stroke were presented at annual meeting of International Stroke Conference (ISC) in Honolulu. The trials, SYNTHESIS expansion and IMS-III, had received great attention from many neurologists and neurointerventionalists, as they were multicenter, randomized, controlled trials comparing clinical results of endovascular approach versus standard intravenous (IV) recombinant tissue plasminogen activator (tPA) alone. Although it had already been demonstrated that endovascular treatment had higher recanalization rates than standard medical care (IV tPA), clinical outcomes of two methods had not yet been compared directly. The SYNTHESIS expansion trial, led by Alfonso Ciccone (Carlo Poma Hospital, Mantua, Italy), randomly assigned 362 acute ischemic stroke patients within 4.5 hours of symptom onset to receive IV tPA or intraarterial endovascular treatment, including intraarterial thrombolysis with tPA, mechanical clot disruption or retrieval, or a combination of these interventions. This study was initiated under hypothesis that the disadvantage of endovascular treatment in terms of time spent may be offset by more effective recanalization achieved with endovascular This hypothesis was supported by preliminary results of SYNTHESIS study. The primary outcome of survival (free from disability, modified Rankin score (mRS) ≤ 1) was assessed at 3 months. 30.4% of 181 patients given endovascular therapy and 34.8% of 181 patients given tPA were free of disability (mRS ≤ 1). This result demonstrated that intraarterial intervention was not superior to standard medical care for patients with acute ischemic stroke. In addition, there were no between-group differences in mortality at 90 days (14.4% in endovascular group versus 9.9% in IV tPA group, p = 0.22) or symptomatic intracranial hemorrhage within 7 days (6% in each group). Notably, patients in endovascular group did not undergo treatment initiation until one hour after tPA group, with median onset-to-treatment times of 3.75 hours and 2.75 hours, respectively. In conclusion, clinical benefit of endovascular treatment of acute stroke, when compared with IV tPA, could not be proven by SYNTHESIS expansion trial. However, Ciccone and colleagues presented that generalizability of results may be limited because demonstrating presence of an occlusion was not necessary for inclusion in trial. They said that selection of patients on basis of demonstration of vascular occlusion with noninvasive method may provide endovascular treatment superiority. Another recent trial, IMS III, is a randomized, multicenter, open-label clinical trial that examined whether combined intravenous and endovascular treatment is superior to standard IV tPA treatment alone for patients with acute stroke. Subjects were randomly assigned to combined or standard therapy within 3 hours of stroke onset in a 2:1 ratio. Endovascular treatment included a choice of catheters and devices or intraarterial tPA based upon lesion characteristics, experience and training of investigator, and specified use of devices. At outset, only one device was available, Concentric Merci retriever, but trial leadership recognized that endovascular technology would evolve. In order to keep trial clinically relevant and optimize endovascular approach, additional devices including stent retriever, Penumbra system, and microsonic SV infusion system were allowed as each became cleared for clinical use by Food and Drug Administration. Contrary to SYNTHESIS trial, computed tomography angiography (CTA) was routinely used in identification of occlusion except at beginning of trial. According to journal articles, IMS III study was stopped after 656 participants had been randomized, because it was clear there was no significant difference between two approaches. In overall analysis, 90 day rate of survival free from disability (mRS < 2) was 30.4% in endovascular group and 34.8% in IV tPA group, an insignificant difference (OR 0.71; 95% confidence CI, 0.44 to 1.14). There was no statistically significant difference between interventions for primary endpoint. The absolute difference between groups was 1.5% (95% CI, -6.1% to 9.1%) when adjusted for stroke severity by National Institutes of Health Stroke Scale (NIHSS) score. Although high recanalization rates using endovascular approach were achieved with active use of a thrombectomy device in this study, clinical outcome was disappointing. This result of IMS III also demonstrated that effective recanalization rate of endovascular therapy cannot offset time required for completion of endovascular treatment. Additionally, it was concluded that bridging therapy should not be considered routine protocol but instead should be thought of as a highly-selective therapeutic option. Despite fact that these two trials comprise research on extended application of endovascular approach in overcoming standard medical treatment, management guidelines for acute ischemic stroke have remained unchanged. However, merit of bridging method, which has been commonly used to recanalize large artery occlusions, was brought into question by these trials. The window of time during which endovascular approach may be attempted (4.5-6h) is so narrow that amount of patients for which this procedure may be indicated was significantly decreased. With fewer patients receiving endovascular recanalization therapy, there is less opportunity for trainees to gain experience in intraarterial thrombectomy, and hospitals or medical insurance companies may hesitate to use willingly money for maintenance of emergent neuroendovascular system. Even more damaging, ability to recruit patients to new trials that assess superiority of endovascular treatment will be difficult. Not every result was unfriendly to endovascular treatment, however. In IMS III, for predefined subgroups of patients with an NIHSS score of 20 or higher, indicating severe stroke (endovascular therapy, 23.5%; IV tPA alone, 16.7%, p = 0.07), comparison of functional outcomes between endovascular and medical groups showed a tendency toward a better outcome in endovascular group. This result may indicate that more severe stroke associated with proximal arterial occlusion, including carotid T and proximal M1, would potentially have a greater benefit with endovascular approach, as these clot locations may be highly amenable to endovascular therapy. The role of endovascular therapy is considered to be more critical in proximal artery occlusion than distal artery occlusion. To this end, it would be helpful if IMS III investigators additionally report rescult of subgroup comparisons using CTA. Each time encountering patients with acute stroke, we will be conflicted between our empirical knowledge and verified evidence. The myth has been debunked, but challenge is still present. The endovascular therapy system that is able to start endovascular approach as soon as patient come to hospital and more effective thrombectomy device such as stentriever, will allow endovascular treatment to play critical role in treatment of stroke.

PurposeThe purpose of this study was to investigate the frequency and risk factors of procedure-related thromboembolism on diffusion-weighted imaging (DWI) associated with aneurysmal coil embolization.Materials and MethodsWe prospectively evaluated 39 consecutive patients with a cerebral aneurysm with DWI after coil embolization. All hyperintense lesions on DWI with a drop of apparent diffusion coefficient values were classified into acute thromboembolic infarction (larger than 5 mm in maximal diameters, and located in the vascular territory of the parent artery) and silent microembolism (single or multiple tiny dot-like lesion, less than 5 mm, usually 1-2 mm in size). Possible risk factors for thromboembolic events included vascular risk factors, aneurysmal factors, and procedure-related factors.ResultsHyperintense lesions on DWI were seen in 17 (43.6%) patients and symptomatic DWI positive lesions were four (10.3%). Acute thromboembolic infarction was observed in seven (17.9%) patients and silent microembolism in 14 (35.9%) patients. Numbers of silent microembolism ranged from 1 to 15 (mean: 2.86, standard deviation: 3.74). Silent microembolisms were located at ipsilateral (n=3, 21.4%), contralateral (n=5, 35.7%), bilateral (n=4, 28.6%), and not related (n=2, 14.3%) to the procedure site. There were no statistical significant risk factors in acute thromboembolic infarction. However, incidence of silent microembolisms was significantly correlated with left side approach (odds ratio, 4.44, 95% confidence interval, 1.08-18.36; P=0.03).ConclusionLeft side approach may have increased the likelihood of asymptomatic multiple scattered microemboli after aneurysmal coiling procedures. Particular care must be taken in the handling of guiding catheters, especially when proving left side great vessels.

Displacement of distal ventriculo-atrial (VA) shunt is not uncommon. However, misplacement of the distal catheter of VA shunt in the internal jugular vein is a possibility, especially when conducted without intraoperative monitoring. We describe a patient in whom a VA shunt was performed due to failure of ventriculo-peritoneal shunt and the distal catheter of the shunt was found to be misplaced in the left internal jugular vein. Endovascular intervention via femoral vein was used to retrieve the distal catheter.

PurposeVerifyNow antiplatelet assays were performed before and after stenting for various cerebral artery stenoses to determine the effect of the procedure itself to the function of dual antiplatelets given.Materials and MethodsA total of 30 consecutive patients underwent cerebral arterial stenting procedure were enrolled. The antiplatelet pretreatment regimen was aspirin (100 mg daily) and clopidogrel (300 mg of loading dose followed by 75mg daily). VerifyNow antiplatelet assay performed before and right after stenting. The two test results were compared in terms of aspirin-reaction unit (ARU), P2Y12 reaction units (PRU), baseline (BASE), and percentage inhibition. We evaluated occurrence of any intra-procedural in-stent thrombosis or immediate thromboembolic complication, and ischemic events in 1-month follow-up.ResultsThe median Pre-ARU was 418 (range, 350-586). For clopidogrel the medians of the pre-BASE, PRU, and percent inhibition were 338 (279-454), 256 (56-325), and 27% (0-57%). The medians of the post-ARU, BASE, PRU, and percent inhibition after stenting were 469 (range, 389-573), 378 (288-453), 274 (81-370), and 26% (0-79%). There was a significant increase of ARU (p=0.045), BASE (p=0.026), and PRU (p=0.018) before and after stenting. One immediate thromboembolic event was observed in poor-response group after stenting. There was no in-stent thrombosis and ischemic event in 1-month follow-up.ConclusionWe observed a significant increase of platelet reactivity to dual antiplatelet therapy right after stenting procedure for various cerebral arterial stenoses.

PurposeThe complex angioarchitecture of spinal dural arteriovenous fistulas (SDAVFs) sometimes preclude angiographic analyses or superselective procedures. Therefore, the effectiveness of 3 dimensional rotational angiography (3DRA) as a detailed imaging technique for SDAVFs was evaluated.Materials and MethodsOf 57 patients with spinal vascular malformations, recent 13 SDAVF patients underwent 3DRA. The advantage of 3DRA compared to digital subtraction angiography (DSA) in imaging SDAVF was assessed. Angioarchitecture of SDAVF was focused on location, number, and course of feeders and draining vein. Appropriate angled views were also selected to reveal the segmental artery and feeders.Results3DRA technique provided additional information for imaging evaluation of SDAVFs compared to DSA; the presence of multiple feeders, including their transdural portions, as well as their courses. The contralaterally angled anterior-oblique-caudal (spider) view showed the radicular feeder by separating the intercostal artery and the dorsal muscular branch. The bottom-to-up (tunnel) view was useful for revealing the location (ventral vs. dorsal) including sharp medial turn of the dural feeder. The dual mode, which displays both vessels and bones, revealed the course of the feeders and the fistula related to the spinal bony column.ConclusionBecause spinal vasculature overlaps in DSA, 3DRA revealed additional information for evaluations of the number and transdural course of fistular feeders in SDAVFs, and it offers working angles to obtain appropriate views.

PurposeSince we reported about a landmark technique to reopen an occluded subclavian artery, we have faced difficulty in using protection devices in the vertebral artery to protect against thromboembolism from the reversed steal phenomenon after angioplasty and stenting. Therefore, we are presenting an optimal solution in using a protection device while recanalizing the occluded subclavian artery.Materials and MethodsAmong 21 cases of stenting for subclavian artery steno-occlusion, we applied the landmark technique at the opposite end of an occluded segment in 4 patients and used a protection device in two patients. Because the embolic protection device was placed in the vertebral artery via the brachial artery, optimal angioplasty and stenting via the brachial route were limited. Therefore, angioplasty via the trans-brachial approach was needed to be followed by stenting through a trans-femoral approach. We estimated the safe and optimal steps for placement and retrieval of the protection devices in addition to stenting.ResultsThe procedure was safely performed when a stent was introduced via the femoral artery and a protection device was used via the brachial artery. However, in cases when a guidewire wasn't passed via the transfemoral route, simultaneous use of two systems via the brachial route could cause friction of devices or trapping of protection devices in a stent. When a protection device was trapped in a deployed stent, we retrieved the protection device with a 4F angiocatheter by selectively rotating the catheter tip. To avoid such procedural difficulty, we recommend using a transbrachial angioplasty followed by trans-femoral stenting while placing the protection device in the vertebral artery via the trans-brachial route.ConclusionIf a guidewire is not passed through using a trans-femoral approach while performing the landmark technique, changing the stenting route from brachial to the femoral artery can be useful after securing the lumen in the occluded subclavian artery after angioplasty via the brachial artery.

Embolization of an aneurysm at the proximal A1 segment of the anterior cerebral artery (ACA) is technically challenging. We treated four consecutive patients with unruptured aneurysms at the proximal portion of the A1 segment of the ACA. We tested various microcatheter tip shapes before we successfully embolized a lesion with a zigzag-shaped microcatheter tip, which was made by steam shaping. The shape of this microcatheter tip resembled the letter "Z", had a relatively long distal straight segment and was helpful in prompt catheterization of the aneurysm sac and stable placement of the catheter and delivery of coils.