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There have recently been reports of patients who developed postprocedural symptoms or alterations due to delayed foreign body embolisms observed in imaging findings. Polymer coating of devices have been described as a possible cause of foreign body embolisms, manifesting in delayed granulomatous responses and exhibiting characteristic imaging findings. In four of 4,025 patients who underwent coil embolization in our hospital or its affiliated facilities, similar findings were observed. Delayed lesions appeared between 1 month and 1 year after the procedures. There was extensive edema in the perfusion area of the treated vessels. In two cases examined by contrast-enhanced magnetic resonance imaging, multiple solid enhancing lesions within vasogenic edema were observed. Biopsy revealed a membranous foreign body in a blood vessel with surrounding foreign body granuloma formation in 1 case. Because these findings are similar to those of cases reported previously, they were considered as a foreign body embolism due to coating separations from the devices. Polymer coating separation occurs most frequently from guidewires. Especially if a metal introducer is used, the risk of separation increases. Surgeons should carefully follow the manufacturers’ instructions when they use these devices and should acknowledge and report any events that may occur. Although these complications are extremely rare, further studies are warranted of similar cases; and we should prepare and share information on these intravascular devices for wide-scale dissemination in the industry.

The management of giant vertebrobasilar junction (VBJ) aneurysms is extremely challenging. Flow diverter (FD) therapy has become an important alternative to treat difficult intracranial aneurysms for both open surgery and conventional endovascular therapy. Herein, we report a rare case of a giant fusiform VBJ aneurysm in a child that is successfully treated with FD therapy.

Dural arteriovenous fistula (DAVF) of the anterior condylar confluence (ACC) is a rare entity accounting for about 3.6% of all DAVFs. We report on a 63-year-old male patient who presented with pulsatile tinnitus. Angiography revealed a DAVF supplied mainly by neuromeningeal branches of bilateral ascending pharyngeal arteries and draining into the ACC. Transvenous transjugular coil embolization was performed resulting in complete obliteration of the fistula and resolution of the symptoms. Due to the complexity of this venous structure at the skull base, detailed angiographic study is crucial for proper therapeutic planning and management of the patient. We here discuss the clinico-radiological features and various treatment modalities of the ACC DAVF.Nepal Journal of Neuroscience, Volume 15, Number 2, 2018, page: 41-44

A delayed aneurysm rupture after flow diverter therapy is a rare but serious complication. Due to the anatomical specificity, a delayed rupture of a carotid cavernous aneurysm may cause a direct carotid cavernous fistula (dCCF). We present a novel therapeutic approach for treatment of dCCF after flow diverter therapy using the Pipeline embolization device (PED). An 86-year-old woman suffered from dCCF after PED embolization. A microcatheter was advanced through the transvenous approach into the cavernous sinus (CS) and further inserted into the aneurysm sac via the rupture point. Coil embolization of both the aneurysm sac and a small part of the CS adjacent to the fistulous site could achieve not only the immediate aneurysm occlusion but also the rupture point obliteration with a small amount of coil mass in the CS.

Coiling and clipping are standard treatment strategies for cerebral aneurysms. Regardless of the strategy used, recanalization may affect the patient’s prognosis. The aim of this study was to histologically and morphologically compare the tissue proliferation after coil embolization using bare platinum coils versus second-generation hydrogel coils (HydroSoft/HydroFrame; MicroVention, Inc., Aliso Viejo, CA, USA). Endothelial-like cell proliferation was seen in both groups at 2 weeks after surgery. Macroscopic findings showed a tighter layer at 4 weeks in the hydrogel coil group, and histological and immunohistochemical findings revealed endothelial cell proliferation. This layer became much thicker and tighter at 4 weeks after surgery. Aneurysms treated with second-generation hydrogel coils may be more stable and have a lower incidence of recanalization than those treated with bare platinum coils because of the tight endothelial layer proliferation.

BACKGROUND AND PURPOSE: Y-configuration stent-assisted coil embolization is used for treating wide-neck aneurysms. Noninvasive alternatives to x-ray DSA for follow-up after Y-configuration stent-assisted coil embolization treatment are required. This study aimed to assess the usefulness of non–contrast-enhanced MRA by using a Silent Scan (silent MRA) for follow-up after Y-configuration stent-assisted coil embolization for basilar tip aneurysms. MATERIALS AND METHODS: Seven patients treated with Y-configuration stent-assisted coil embolization for basilar tip aneurysms underwent silent MRA, 3D TOF-MRA, and DSA. Silent MRA and 3D TOF-MRA images were obtained during the same scan session on a 3T MR imaging system. Two neuroradiologists independently reviewed both types of MRA images and subjectively scored the flow in the stents on a scale of 1 (not visible) to 5 (nearly equal to DSA) by referring to the latest DSA image as a criterion standard. Furthermore, we evaluated the visualization of the neck remnant. RESULTS: In all patients, the 2 observers gave a higher score for the flow in the stents on silent MRA than on 3D TOF-MRA. The average score ± standard deviation was 4.07 ± 0.70 for silent MRA and 1.93 ± 0.80 (P < .05) for 3D TOF-MRA. Neck remnants were depicted by DSA in 5 patients. In silent MRA, neck remnants were depicted in 5 patients, and visualization was similar to DSA; however, in 3D TOF-MRA, neck remnants were depicted in only 1 patient. CONCLUSIONS: Silent MRA might be useful for follow-up after Y-configuration stent-assisted coil embolization.

Flow diversion stents (FDSs) are constructed from high-density braided mesh, which alters intra-aneurysmal hemodynamics and leads to aneurysm occlusion by inducing thrombus formation. Although there are potential complications associated with FDS embolization, one of the serious complications is the parent artery occlusion due to the in-stent thrombosis. A 72-year-old woman with a symptomatic giant fusiform aneurysm in the cavernous segment of ICA underwent single-layer pipeline embolization device (PED) embolization. Six-month and 1-year follow-up conventional angiographies showed the residual blood flow in the aneurysm. Two-year follow-up MRI showed the aneurysm sac shrinkage and the antiplatelet therapy was discontinued. The patient suffered from symptomatic parent artery occlusion due to the in-stent thrombosis, 4 months after antiplatelet therapy discontinuation. The patient with the incompletely occluded aneurysm after PED embolization should be given long-term antiplatelet therapy because of the risk of delayed parent artery occlusion.

BACKGROUND AND PURPOSE: The flow-diverter device has been established as a treatment procedure for large unruptured intracranial aneurysms. The purpose of this study was to compare the usefulness of Silent MR angiography and time-of-flight MRA to assess the parent artery and the embolization state of the aneurysm after a flow-diverter placement. MATERIALS AND METHODS: Seventy-eight large, unruptured internal carotid aneurysms in 78 patients were the subjects of this study. After 6 months of treatment, they underwent follow-up digital subtraction angiography, Silent MRA, and TOF-MRA, performed simultaneously. All images were independently reviewed by 2 neurosurgeons and 1 radiologist and rated on a 4-point scale from 1 (not visible) to 4 (excellent) to evaluate the parent artery. The aneurysmal embolization status was assessed with 2 ratings: complete or incomplete occlusion. RESULTS: The mean scores of Silent MRA and TOF-MRA regarding the parent artery were 3.18 ± 0.72 and 2.31 ± 0.86, respectively, showing a significantly better score with Silent MRA (P < .01). In the assessment of the embolization of aneurysms on Silent MRA and TOF-MRA compared with DSA, the percentages of agreement were 91.0% and 80.8%, respectively. CONCLUSIONS: Silent MRA is superior for visualizing blood flow images inside flow-diverter devices compared with TOF-MRA. Furthermore, Silent MRA enables the assessment of aneurysmal embolization status. Silent MRA is useful for assessing the status of large and giant unruptured internal carotid aneurysms after flow-diverter placement.

Purpose We aimed to analyse the patency rate of the anterior choroidal artery, and presented imaging and neurological findings, after deployment of a flow diverter in the anterior choroidal artery in the treatment of patients with intracranial aneurysms. Methods Among the 139 patients who underwent a flow diverter deployment from December 2012 to September 2017 in our hospital, there were 21 patients (15.1%) for whom their anterior choroidal artery was covered for the procedure with a flow diverter. The patients' age, sex, size of aneurysm and the presence or absence of an anterior choroidal artery occlusion, neurological findings and postoperative infarction in the anterior choroidal artery region were analysed retrospectively. Results The mean age of the six male and 15 female patients was 61.5 years (range 32–77 years). The mean maximal diameter of the aneurysms was 16.4 mm (range 10.0–29.4 mm). The anterior choroidal artery was patent in all 21 patients; however, a haemodynamic alteration in the anterior choroidal artery was detected in one patient. Postoperatively, hemiparesis was observed in two patients (9.5%) and a visual field defect in one patient (4.8%), both of which were the symptoms of infarction of the cortical branch of the middle cerebral artery or retinal artery ischaemia. However, no patients had symptoms due to ischaemia of the anterior choroidal artery confirmed with magnetic resonance imaging. Conclusions In all patients who underwent flow diverter deployment, the anterior choroidal artery was patent and no ischaemia was detected in the imaging or evidenced by neurological findings. Therefore, flow diverter deployment in the anterior choroidal artery was considered to be a safe procedure.

Background Flow diversion with the Pipeline embolization device (PED) is a widely accepted treatment modality for aneurysm occlusion. Previous reports have shown no recanalization of aneurysms on long-term follow-up once total occlusion has been achieved. Case description We report on a 63-year-old male who had a large internal carotid artery cavernous segment aneurysm. Treatment with PED resulted in complete occlusion of the aneurysm. However, follow-up angiography at four years revealed recurrence of the aneurysm due to disconnection of the two PEDs placed in telescoping fashion. Conclusion Herein, we present the clinico-radiological features and discuss the possible mechanisms resulting in the recanalization of aneurysms treated with flow diversion.

Flow diverters (FDs) have been developed for intracranial aneurysms difficult to treat with conventional endovascular therapy and surgical clipping. We reviewed 94 patients with 100 large or giant unruptured internal carotid artery (ICA) aneurysms treated with Pipeline embolization device (PED) embolization from December 2012 to June 2017 at Juntendo University Hospital. The patients' mean age was 63.4 years (range, 19-88), and there were 90 women 89.4%. Aneurysm locations were: C4 (45), C3 (4), and C2 (51) in ICA segments. Mean aneurysm size and neck width were 16.9 ± 6.8 mm and 8.3 ± 4.4 mm, respectively, in 40 symptomatic and 60 asymptomatic aneurysms. Follow-up catheter angiographies of 85 patients with 90 aneurysms showed no filling in 62 aneurysms (68.9%), entry remnant in 16 (17.8%), subtotal filling in 11 (12.2), and total filling in 1 (1.1%) with a mean follow-up of 10.2 ± 5.6 months. In-stent stenosis occurred in 1 patient and parent artery occlusion in 2 during follow-up. Hemorrhagic complications occurred in 4 (4.3%): delayed aneurysm rupture (2) and intraparenchymal hemorrhage (2). Ischemic complications with neurological symptoms occurred in 2 (2.1%): very delayed device occlusion (1) and intraprocedural distal embolism (1). Eighteen patients (45%) showed improvement in pre-existing cranial nerve dysfunction because of the aneurysm's mass effect, 3 patients (7.5%) worsened. One patient died of systemic organ failure unassociated with the procedure. Morbidity and mortality rates were 4.3% and 1.1%, respectively. PED embolization for unruptured large and giant ICA aneurysms is safe and efficacious. Physicians should be observant of characteristic risks associated with FD therapy.

Background and purpose We report the results of endosaccular coil embolization of asymptomatic unruptured intracranial aneurysms (UIAs) in elderly patients (≥65 years). Materials There were 375 elderly patients with 400 asymptomatic UIAs. Patients were divided into two groups: group A included patients aged 65–74 years and group B patients aged ≥75 years. Results Endovascular procedures were completed in 97.8% of patients. Immediate anatomical outcomes showed complete occlusion in 53.7%, residual neck in 18.9%, and residual aneurysm in 27.4%. Anatomical follow-ups (mean 36.3±28.1 months) were unchanged in 55.7%, improved in 22.6%, minor recurrence in 11.5%, and major recurrence in 10.2%. Procedure related complications occurred in 31 patients (8.3%). 15 patients had ischemic and 10 hemorrhagic complications. Retreatments were performed in 16 patients (4.3%). Among 366 patients technically completed, 363 (99.2%) showed a favorable clinical outcome (modified Rankin Scale (mRS) score 0 at 30 days. The latest clinical follow-up outcomes showed: mRS score 0 in 362 patients; mRS score 1 in one; mRS score 3 in one; mRS score 4 in one; and mRS score 5 in one patient. Permanent morbidity and mortality rates were 1.1% and 0%, respectively. There were no statistically significant differences in gender, comorbidities, aneurysm size, neck width, dome-to-neck ratio, immediate anatomical outcomes, anatomical follow-up outcomes, or procedure related complications between the groups. Conclusions Endosaccular coil embolization is safe and feasible for elderly patients with asymptomatic UIAs. Old age itself should not be a contraindication.

It has been proposed that Ataxin-2, a member of the like-Sm (LSm) protein family, participates in the regulation of RNA metabolism through interaction with PABPC1. However, the exact biological mechanism and in vivo targets remain unknown. Here, we report that Ataxin-2 binds directly to RNAs in a PABPC1-independent manner. High-throughput sequencing of Ataxin-2-bound RNAs prepared by PAR-CLIP revealed that Ataxin-2 binds predominantly to uridine-rich elements, including well-characterized cis-regulatory AU-rich elements, in the 3' UTRs of target mRNAs. Gene expression analysis after Ataxin-2 depletion or overexpression revealed that Ataxin-2 stabilizes target mRNAs and increases the abundance of the corresponding proteins. A tethering assay demonstrated that Ataxin-2 elicits this effect by direct interaction with mRNAs. We also found that disease-associated polyglutamine expansion downregulates the physiological activity of Ataxin-2. These findings suggest that Ataxin-2 is an RNA-binding protein that targets cis-regulatory elements in 3' UTRs to stabilize a subset of mRNAs and increase protein expression.

Matrin3 is an RNA-binding protein that is localized in the nuclear matrix. Although various roles in RNA metabolism have been reported for Matrin3, in vivo target RNAs to which Matrin3 binds directly have not been investigated comprehensively so far. Here, we show that Matrin3 binds predominantly to intronic regions of pre-mRNAs. Photoactivatable Ribonucleoside-Enhanced Cross-linking and Immunoprecipitation (PAR-CLIP) analysis using human neuronal cells showed that Matrin3 recognized pyrimidine-rich sequences as binding motifs, including the polypyrimidine tract, a splicing regulatory element. Splicing-sensitive microarray analysis showed that depletion of Matrin3 preferentially increased the inclusion of cassette exons that were adjacent to introns that contained Matrin3-binding sites. We further found that although most of the genes targeted by polypyrimidine tract binding protein 1 (PTBP1) were also bound by Matrin3, Matrin3 could control alternative splicing in a PTBP1-independent manner, at least in part. These findings suggest that Matrin3 is a splicing regulator that targets intronic pyrimidine-rich sequences.

Objective: Treatment of very small cerebral aneurysms remains challenging. The aim of the present study was to assess the feasibility and safety of endovascular treatment for these aneurysms.Methods: Between 2003 and 2008, a total of 831 aneurysms were selectively occluded with coils. Of these aneurysms, 110 (13.2%) were very small (57 ruptured and 53 unruptured). We performed a retrospective analysis of these cases using the Glasgow outcome scale (GOS) for clinical followup and digital subtraction angiography (DSA) and/or MR angiography (MRA) for angiographic followup.Results: Mean duration of followup was approximately one year. Overall clinical outcome of patients showed 78 patients (76.5%) with good recovery, six (5.9%) with moderate disability, nine (8.8%) with severe disability, five (4.9%) with vegetative state, and four (3.9%) that had died. All asymptomatic unruptured aneurysms showed good recovery. No delayed rebleeding was observed. There were no procedural related complications. We encountered major recanalization in four aneurysms (10%) of the followedup ruptured aneurysms, requiring retreatment with coils; there were no major recanalizations in cases of unruptured aneurysms. Six out of nine (67%) unruptured aneurysms showing initial body filling had changed into complete occlusion at later follow up. Conclusions: Endovascular treatment may be a feasible and effective therapeutic alternative for very small aneurysms. Endovascular coil embolization of very small ruptured aneurysms was effective in controlling hemorrhage; however, this technique requires strict followup and may necessitate additional treatment. By contrast, outcome of very small unruptured aneurysms was excellent.

BACKGROUND AND PURPOSE: Endovascular TVE for DCCF is used for curative purposes, but serious complications can be caused with inadequate embolization. Our aim was to report clinical characteristics, angiographic findings, and results of endovascular TVE in patients presenting with DCCF. MATERIALS AND METHODS: We performed a retrospective analysis of 44 consecutive patients with DCCF treated by TVE. Approach routes, angiographic results, clinical outcomes, and complications were assessed. RESULTS: An approach via the internal jugular vein and inferior petrosal sinus was possible in 90% of patients, with complete occlusion of the fistula in 81.6% of patients. A minor residual shunt remained in 13.6% of patients, while a significant shunt remained in 4.5%. In 4 patients, add-on management with transarterial embolization was useful, and in 2 patients with residual shunt, radiosurgery was used. With long-term follow-up (6–40 months), we encountered recanalization/recurrence in 4 patients (9.1%). Complications were seen in the form of permanent morbidity in 3 patients (7%) and transient morbidity in 6 patients (14%). CONCLUSIONS: For endovascular treatment of DCCF, a transvenous approach was effective in most of our patients; however, some adverse effects were encountered. If AV shunts remain after transvenous treatment, additional modalities must be considered.

We retrospectively reviewed our own experiences of coil embolization for intracranial aneurysms regarding recanalization. Between July 2001 and December 2007, a total of 740 patients underwent coil embolization at our institution or affiliated hospitals. Among those, 271 patients with 278 aneurysms who underwent follow-up cerebral angiography more than 12 months after the initial treatment were the subjects of this study. Immediate angiographic results showed complete occlusion in 72.4%, residual neck in 14.0%, and residual filling in 13.6%. Mean follow-up periods were 21.7 and 20.6 months for ruptured and unruptured aneurysms, respectively. The overall recanalization rate was 29.4% (major recurrence 12.6%, minor recurrence 16.8%). Previous rupture and morphology of wide-neck (≥4 mm) or large size (≥10 mm) and location of posterior circulation were the significant risk factors of recanalization (P Coil embolization of intracranial aneurysms is proving to be a safe method of protecting aneurysms from rupture. However, endovascularly treated patients, particularly those with recanalization risk factors, should undergo long-term follow-up.

Background Intensive lipid-lowering therapy with statins reduces levels of low-density lipoprotein (LDL)-cholesterol (C) and improves plaque volume and composition in patients with cardiovascular disease. Furthermore, rosuvastatin ameliorated carotid stenosis in the ASTEROID study, and altered the composition of plaques in a predominantly Caucasian study population in the ORION study. However, it is not known whether statin therapy achieves similar quantitative improvement in carotid artery plaque in other ethnic groups. Methods and Results Fifty patients with hypercholesterolemia (LDL-C ≥120 mg/dl) and a maximum carotid intima-media thickness ≥1.8 mm will be enrolled and treated with rosuvastatin at a dose of 5 mg/day for 96 weeks. The primary endpoints will be the percent change of carotid plaque volume and the change in plaque composition after 96 weeks of treatment, as evaluated by magnetic resonance imaging. Conclusions The CHALLENGER study will provide a noninvasive assessment of the changes in carotid plaque volume and composition achieved by reduction of LDL levels in Japanese patients with carotid stenosis on long-term rosuvastatin therapy. (Circ J 2009; 73: 111 - 115)

ISAT findings and the improvement of the endovascular devices have led to increased use of endovascular surgery (endosaccular coil embolization) in the treatment of ruptured cerebral aneurysms. Since April 2003, Juntendo University and some affiliated hospitals have adopted an endovascular surgery as the first treatment of choice for ruptured cerebral aneurysms. Furthermore, a few affiliated hospitals adopted endovascular surgery when it was thought to be superior to surgical clipping. As a result, 205 patients (127 females, 78 males) with a mean age of 59.3 years (range 22-91) underwent endovascular surgery for a ruptured cerebral aneurysm within 72 hours from onset between April 2003 and March 2007. We report in this study our experiences of endovascular surgery in the acute stage for subarachnoid hemorrhage due to rupture of a cerebral aneurysm. The frequent locations of the aneurysms were of the anterior communicating artery (36.1%), internal carotid artery (31.2%) and the middle cerebral artery (17.1%). The rate of the aneurysms in the posterior circulation was 12.2%. The mean aneurysmal dimensions were 5.6±2.5 mm for the long axis, 4.0±2.0 mm for the short axis, and 2.9±1.2 mm for the neck width. The aneurysms with 10 mm or larger size comprised 7.8% of all aneurysms. The immediate angiographic results showed complete occlusion at 69.8%, neck remnant at 15.1%, body filling at 12.2% and attempted cases at 2.9%. Clinical outcome excluding attempted cases, according to the Glasgow outcome scale, at discharge or transfer to another hospital shows that the favorable outcome consisted of either good recovery or moderate disability (81.4%), and the unfavorable outcome consisted of either severe disability, persistent vegetative state or death (18.6%). The overall permanent morbidity and mortality rate directly related to the procedure was 1.5%. We had only 1 case of bleeding from the coiled aneurysm leading to death. Symptomatic cerebral vasospasm developed in 17.6% of all patients. Radiological evaluations after 3 months by either cerebral angiography or brain magnetic resonance angiography showed the following anatomical changes of the coiled aneurysms: unchanged, 51.9%; minor recurrence, 25.5%; major recurrence, 16.0% and progressive thrombosis, 6.6%. All aneurysms with major recurrences were retreated endovascularly. Endovascular surgery in the acute stage of ruptured cerebral aneurysms was safe and improved the clinical outcome. The problem of treated aneurysm recurrence, however, still remains to be resolved. Therefore, patients who have undergone endovascular surgery for a ruptured cerebral aneurysm, should be closely followed up with clinical and radiological evaluations.

This study shows the frequency and types of carotid-cavernous fistula (CCF) complications that occurred during endovascular treatment. Transarterial endovascular surgeries involving the anterior circulation were performed for 1071 cases at our hospitals during four years. CCFs occurred in nine of 1071 cases (0.8%). CCF risk factors were female sex ( p = 0.032), aneurysmal location in the paraclinoid portion ( p

The blood supply to the region of the cavernous sinus is provided by interconnecting branches of the internal and external carotid arteries, and it is from these vessels that dural arteriovenous fistulas (DAVFs) arise. It is very rare that DAVFs are located at the intercavernous sinuses region; in this case, a proper localization of the fistulous site is of extreme importance in order to successfully eliminate the disease. Here, we describe a case of a 65-year-old female with intercavernous sinus DAVF. A complete obliteration of the fistulous points was performed by coil embolization through a transvenous approach. i 2014 S. Karger AG, Basel

A 41-year-old man, without underlying health problems or traumatic episodes, presented with a rare paravertebral arteriovenous fistula (AVF) causing radiculopathy manifesting as gradually progressive right grip weakness, and right thumb, index, and middle finger numbness. Digital subtraction angiography revealed a high flow, single hole paravertebral AVF fed by the right thyrocervical trunk that drained into the epidural venous plexus. The patient underwent endovascular embolization of the AVF via the transarterial approach. The fistula was completely occluded by coil embolization. Postembolization, clinical symptoms improved and 6-month follow-up angiography showed no recurrence of the fistula. Paravertebral AVF is a rare vascular malformation occurring outside the dura mater, fed by dural or epidural branches, and draining primarily into the epidural venous plexus. Paravertebral AVF is usually asymptomatic because of a "reflux-impending mechanism" within the dural sleeves that prevents retrograde drainage into the perimedullary veins. However, in the present case, mechanical compression of the radicular nerve due to a dilated epidural venous plexus resulted in neurological symptoms. We conclude that endovascular surgery is an effective treatment strategy for paravertebral AVF.

Intracranial aneurysms are extremely rare in infants, and to our knowledge only seven infants treated for ruptured spontaneous dissecting aneurysms have been reported. Good outcomes have been achieved with endovascular treatment of infantile aneurysm. We the endovascular treatment of a one-month-old girl for ruptured dissecting aneurysm located in the anterior communicating artery, and the unique radiological changes that were observed during the perioperative and follow-up periods. These changes suggest that blood coagulation and fibrinolytic response play a part in the repair and healing processes of dissecting aneurysms. Careful neuroradiological surveys are needed for pediatric dissecting aneurysms treated endovascularly.

After coil embolization, recanalization in cerebral aneurysms adversely influences long-term prognosis. Proliferation of endothelial cells on the coil surface may reduce the incidence of recanalization and further improve outcomes after coil embolization. We aimed to map the expression of proliferating tissue over the aneurysmal orifice and define the temporal profile of tissue growth in a swine experimental aneurysm model. We compared the outcomes after spontaneous thrombosis with those of coil embolization using histological and morphological techniques. In aneurysms that we not coiled, spontaneous thrombosis was observed, and weak, easily detachable proliferating tissue was evident in the aneurysmal neck. In contrast, in the coil embolization group, histological analysis showed endothelial-like cells lining the aneurysmal opening. Moreover, immunohistochemical and morphological analysis suggested that these cells were immature endothelial cells. Our results indicated the existence of endothelial cell proliferation 1 week after coil embolization and showed immature endothelial cells in septal tissue between the systemic circulation and the aneurysm. These findings suggest that endothelial cells are lead to and proliferate in the former aneurysmal orifice. This is the first examination to evaluate the temporal change of proliferating tissue in a swine experimental aneurysm model.

Surgical clipping has been the primary treatment option for ruptured distal anterior cerebral artery (DACA) aneurysms. Therefore, the literature on endovascular therapy is sparse. The present study investigated the feasibility and efficacy of endovascular therapy for ruptured DACA aneurysms in 31 patients, 26 females and 5 males (mean age 63.2 ± 12.6 years). Mean aneurysm size and neck width were 4.8 ± 2.3 mm and 2.2 ± 0.7 mm, respectively. The Hunt and Hess (H/H) grades just prior to the treatment were scored as H/H grades 1-3 in 20 patients and H/H grades 4-5 in 11 patients. Fifteen patients had an intraparenchymal hematoma (IPH) surrounding the ruptured aneurysm on the initial computed tomography. Overall, 22 patients had a modified Rankin scale (mRS) score of 0-2 and 9 had a mRS score of 3-6 at discharge. H/H grade was closely related to the clinical outcomes, whereas the presence of IPH was not. Overall immediate angiographic outcomes were complete occlusion in 15, residual neck in 11, and residual aneurysm in 5. The overall recurrence rate was 35.3%. Complications including posttreatment rebleeding occurred in 5 patients. Symptomatic vasospasm occurred in 1 of the 18 patients with H/H grades 1-3. Endovascular therapy of ruptured DACA aneurysms is feasible and effective. However, the risks of recurrence and posttreatment bleeding remain to be resolved.

A 41-year-old man, without underlying health problems or traumatic episodes, presented with a rare paravertebral arteriovenous fistula (AVF) causing radiculopathy manifesting as gradually progressive right grip weakness, and right thumb, index, and middle finger numbness. Digital subtraction angiography revealed a high flow, single hole paravertebral AVF fed by the right thyrocervical trunk that drained into the epidural venous plexus. The patient underwent endovascular embolization of the AVF via the transarterial approach. The fistula was completely occluded by coil embolization. Postembolization, clinical symptoms improved and 6-month follow-up angiography showed no recurrence of the fistula. Paravertebral AVF is a rare vascular malformation occurring outside the dura mater, fed by dural or epidural branches, and draining primarily into the epidural venous plexus. Paravertebral AVF is usually asymptomatic because of a "reflux-impending mechanism" within the dural sleeves that prevents retrograde drainage into the perimedullary veins. However, in the present case, mechanical compression of the radicular nerve due to a dilated epidural venous plexus resulted in neurological symptoms. We conclude that endovascular surgery is an effective treatment strategy for paravertebral AVF.

Intensive lipid-lowering therapy with statins reduces levels of low-density lipoprotein (LDL)-cholesterol (C) and improves plaque volume and composition in patients with cardiovascular disease. Furthermore, rosuvastatin ameliorated carotid stenosis in the ASTEROID study, and altered the composition of plaques in a predominantly Caucasian study population in the ORION study. However, it is not known whether statin therapy achieves similar quantitative improvement in carotid artery plaque in other ethnic groups.Fifty patients with hypercholesterolemia (LDL-Cor=120 mg/dl) and a maximum carotid intima-media thicknessor=1.8 mm will be enrolled and treated with rosuvastatin at a dose of 5 mg/day for 96 weeks. The primary endpoints will be the percent change of carotid plaque volume and the change in plaque composition after 96 weeks of treatment, as evaluated by magnetic resonance imaging.The CHALLENGER study will provide a noninvasive assessment of the changes in carotid plaque volume and composition achieved by reduction of LDL levels in Japanese patients with carotid stenosis on long-term rosuvastatin therapy.