Relapsing polychondritis presenting with sero-negative limbic encephalitis

The presented case highlights a rare instance of relapsing polychondritis (RP) manifesting as seronegative limbic encephalitis, an uncommon neurological complication. A 70-year-old female patient with a history of RP-related inflammation, along with neuropsychiatric symptoms, was diagnosed through multidisciplinary collaboration. Swift administration of steroid therapy, followed by azathioprine, led to remarkable physical and cognitive recovery. This case emphasises the importance of a multidisciplinary approach in diagnosing and treating complex autoimmune disorders with neurological manifestations.

Contrast Injection from an Intermediate Catheter Placed in an Intradural Artery is Associated with Contrast-Induced Encephalopathy following Neurointervention

BACKGROUND AND PURPOSE

Contrast-induced encephalopathy can result from neurotoxicity of contrast medium in the affected area. The development of intermediate catheters has allowed guidance of catheters to more distal arteries. This study focused on the association between contrast-induced encephalopathy and contrast injection from an intermediate catheter guided into a distal intradural artery during neurointervention for cerebral aneurysms.

MATERIALS AND METHODS

We retrospectively reviewed 420 consecutive aneurysms in 396 patients who underwent neurointervention for extracranial aneurysms and unruptured intracranial aneurysms at our institution from February 2012 to January 2023. Patients were divided into a group with contrast-induced encephalopathy and a group without. To identify risk factors for contrast-induced encephalopathy, we compared clinical, anatomic, and procedural factors between groups by multivariate logistic regression analysis and stepwise selection.

RESULTS

Among the 396 patients who underwent neurointervention for cerebral aneurysms, 14 (3.5%) developed contrast-induced encephalopathy. Compared with the group without contrast-induced encephalopathy, the group with contrast-induced encephalopathy showed significantly higher rates of patients on hemodialysis, previously treated aneurysms, intradural placement of a catheter for angiography, nonionic contrast medium, and flow-diversion procedures in univariate analyses. Stepwise multivariate logistic regression analysis revealed intradural placement of a catheter for angiography (OR = 40.4; 95% CI, 8.63-189) and previously treated aneurysms (OR = 8.20; 95% CI, 2.26-29.6) as independent predictors of contrast-induced encephalopathy.

CONCLUSIONS

Contrast injection from an intradural artery and retreatment of recurrent aneurysms were major risk factors for contrast-induced encephalopathy. Attention should be paid to the location of the intermediate catheter for angiography to avoid developing contrast-induced encephalopathy.

Evaluation of the direct protective effects of Canagliflozin on the Isoproterenol-induced cell injury in rat cardiomyocytes

Background

Sodium-glucose cotransporter-2 (SGLT2) inhibitors are agents that act by inhibiting glucose and sodium reabsorption in the proximal renal tubule which promotes urinary glucose excretion. More recently, significant benefit data of SGLT2 inhibitors in patients with heart failure, independent of the presence of type 2 diabetes has been reported. We have previously demonstrated that Canagliflozin (Cana), a SGLT2 inhibitor, reduced the ventricular effective refractory period in isoproterenol (ISP)-induced myocardial injury rat model accompanied with the suppression of reactive oxygen species and the elevation of ketone bodies, suggesting the effect of Cana on electrical cardiac remodeling. The direct effect of Cana to the cardiomyocytes and its underlying molecular mechanism was remained to be clarified. We therefore established an ISP-induced neonatal rat ventricular cardiomyocyte (NRVCM) in vitro model, pretreated with Cana and/or ketone bodies.

Methods

Primary NRVCM were isolated from Wistar rats, were pretreated by Cana with or without βOHB (the most abundant ketone body in circulation), followed by a stimulation of ISP (10μM). Cells without drug or ketone body pretreatment were used as control. We then analyzed its effect on cell viability, apoptosis, and mitochondrial membrane potential using MTT assay, TUNEL assay, and mitochondrial membrane potential assay, respectively. MTT assay was also performed with or without PI3k inhibitor, LY294002. The end-labeling of DNA fragmentation were labelled with FITC, followed by the nuclei counterstain with DAPI and were observed with confocal microscope. The apoptotic index was defined as the percentage of TUNEL positive cells / total nuclei.

Results

Cana rescued the reduction of NRVCM cell viability induced by ISP stimulation for 24 hours which was inhibited by LY294002 compared to cells without pretreatment. Interestingly, pretreatment of βOHB with or without Cana improved also the NRCVM cell viability whereas there was no significant difference between these two conditions or with cells treated with Cana only, suggesting the direct protective effect of Cana. In 48 hours of ISP stimulation, the apoptotic index intends to decrease in Cana and/or βOHB compared to cells without pretreatment (Figure 1). Although the mitochondrial function was maintained in Cana-pretreated cells compared to cells without pretreatment, there was no significant difference in βOHB-pretreated cells.

Conclusions

Cana has a direct protective effect on cardiomyocytes cell viability, apoptosis as well as the mitochondrial function impaired by ISP through the cell survival signaling PI3K/Akt pathway. This brings a new insight to the therapeutic target of cardiovascular disease.

Funding Acknowledgement

Type of funding sources: None.

Microcatheter Originating Debris during Neuroendovascular Procedures: Mechanism of Dislodgement and Its Prevention

Embolic material dislodgement from microcatheters can potentially induce subclinical brain damage as evidenced by a delayed enhanced or other type of lesions. Some of the most frequently used microcatheters were investigated in vitro in different setups and combinations with different port insertions and rotating hemostatic valves. It was found that side port application increases injury to the catheter surface and debris dislodgement by conflicting with internal ledges in rotating hemostatic valves. This initial observation suggests the need for measures to remove the produced debris during such procedures.

Delayed Leukoencephalopathy: A Rare Complication after Coiling of Cerebral Aneurysms

BACKGROUND AND PURPOSE

Delayed leukoencephalopathy is a rare complication that occurs after endovascular coiling of cerebral aneurysms. We aimed to describe a clinical picture of delayed leukoencephalopathy and explore potential associations with procedural characteristics.

MATERIALS AND METHODS

We considered endovascular coiling procedures for cerebral aneurysms performed between January 2006 and December 2017 in our institution with follow-up MRIs. We used logistic regression models to estimate the ORs of delayed leukoencephalopathy for each procedural characteristic.

RESULTS

We reviewed 1754 endovascular coiling procedures of 1594 aneurysms. Sixteen of 1722 (0.9%) procedures demonstrated delayed leukoencephalopathy on follow-up FLAIR MR imaging examinations after a median period of 71.5 days (interquartile range, 30-101 days) in the form of high-signal changes in the white matter at locations remote from the coil mass. Seven patients had headaches or hemiparesis, and 9 patients were asymptomatic. All imaging-associated changes improved subsequently. We found indications suggesting an association between delayed leukoencephalopathy and the number of microcatheters used per procedure (P = .009), along with indications suggesting that these procedures required larger median volumes of contrast medium (225 versus 175 mL, OR = 5.5, P = .008) as well as a longer median fluoroscopy duration (123.6 versus 99.3 minutes, OR = 3.0, P = .06). Our data did not suggest that delayed leukoencephalopathy was associated with the number of coils (P = .57), microguidewires (P = .35), and guiding systems (P = .57).

CONCLUSIONS

Delayed leukoencephalopathy after coiling of cerebral aneurysms may have multiple etiologies such as foreign body emboli, contrast-induced encephalopathy, or hypersensitivity reaction to foreign bodies.

Agreement of intracranial vessel diameters measured on 2D and 3D digital subtraction angiography using an automatic windowing algorithm

BACKGROUND AND PURPOSE

Precise vessel measurement plays a major role in size selection of stents used for the treatment of intracranial aneurysms and became even more critical after the introduction of flow diverter stents. We assessed agreement between intracranial vessel diameters of aneurysm patients measured on 2D digital subtraction (2D DSA) and 3D volume rendering digital subtraction angiography (3D DSA) images using an automatic windowing algorithm.

MATERIALS AND METHODS

Ten patients with intracranial aneurysms were enrolled and 120 measurement points were selected on both 2D and 3D DSA images acquired by a biplane angiographic system. Automatic windowing was applied to the 3D DSA images. Inter-method agreement of vessel measurements on 2D and 3D DSA images was assessed by Bland Altman plots and intraclass correlation coefficients (ICC). Inter- and intra-rater agreement of measurements on 3D DSA images were assessed by ICCs.

RESULTS

The mean differences between measurements on 2D and 3D DSA images were 0.14mm for the ICA, and 0.18mm for the ACA and MCA, which is about the size of one 3D DSA image voxel. For ICA measurements, inter-method, inter-rater and intra-rater agreements were good or excellent (consistency and absolute ICC≥0.95). For ACA and MCA measurements, the inter-method, inter-rater and intra-rater agreements were also good or excellent (consistency ICC=0.94, 0.89 and 0.93, absolute ICC=0.83, 0.84 and 0.85 respectively).

CONCLUSIONS

Vessel diameters may be measured on 3D DSA images with sufficient reliability for clinical use when applying an automatic windowing algorithm.

Comparison of hemodynamic parameters that can predict an aneurysmal rupture: 20 patient-specific models experiment

Hemodynamic analysis of cerebral aneurysms is widely performed to understand the mechanism of aneurysmal rupture. Computational fluid dynamics (CFD) studies have suggested that several hemodynamic parameters are associated with such ruptures. However, a number of factors remain to be addressed to correlate these parameters with aneurysmal ruptures, especially under analytical conditions. Specifically, CFD analysis is often performed with rigid wall models due to computational cost limitations. Here, to evaluate the effects of the deformation of the aneurysmal wall, experimental flow measurement with elastic models under pulsating conditions was conducted using three-dimensional particle image velocimetry (3D PIV). By analyzing 20 patient-specific, elastic, silicone aneurysm models, the hemodynamic parameters of ruptured and unruptured aneurysms were statistically compared to identify the variables that can effectively predict an aneurysmal rupture. Our analyses yielded three parameters (average wall shear stress ratio, in-phase deviation ratio, and pressure difference) which could effectively predict an aneurysmal rupture. These results suggested that measurement of wall shear stress (WSS) at both the aneurysm dome and parent artery is important and that pressure difference can also be a potential indicator of aneurysmal rupture.

The impact of deformation of an aneurysm model under pulsatile flow on hemodynamic analysis

Hemodynamic analysis of cerebral aneurysms has been widely carried out to clarify the mechanisms of their growth and rupture. In several cases, patient-specific aneurysm models made of transparent polymers have been used. Even though periodic changes in aneurysms due to the pulsation of blood flow could be important, the deformation of the model geometry and its effect on hemodynamic evaluation has not been fully investigated. In addition, the fabrication accuracy of aneurysm models has not been evaluated even though it may affect the hemodynamic parameters to be analyzed. In this study, the fabrication accuracy of a silicone aneurysm model was investigated. Additionally, the deformation of the model under pulsatile flow as well as its correlation with flow behavior was evaluated. Consequently, a fabrication method for an aneurysm model with high accuracy was established and the importance of the wall thickness of the model was also specified.

Geographic Differences in Endovascular Treatment and Retreatment of Cerebral Aneurysms

BACKGROUND AND PURPOSE

Comparing outcomes between endovascular aneurysm coiling trials can be difficult because of heterogeneity in patients and end points. We sought to understand the impact of geography on aneurysm retreatment in patients enrolled in the Matrix and Platinum Science Trial.

MATERIALS AND METHODS

Post hoc analysis was performed on data from the Matrix and Platinum Science trial. Patients were stratified as either North American or international. Baseline patient demographics, comorbidities, aneurysm characteristics, procedural complications, and clinical and angiographic outcomes were compared.

RESULTS

We evaluated 407 patients from 28 North American sites and 219 patients from 15 international sites. Patient demographics differed significantly between North American and international sites. Aneurysms were well occluded postprocedure more often at international than North American sites (P < .001). Stents were used significantly more often at North American sites (32.7% [133 of 407]) compared with international sites (10.0% [22 of 219]; P < .001). At 455 days, there was no difference in the proportion of patients alive and free of disability (P = .56) or with residual aneurysm filling (P = .10). Ruptured aneurysms were significantly more likely to have been retreated at North American sites within the first year (P < .001) and at 2 years (P < .001). Among all patients for whom the treating physician believed there to be Raymond 3 aneurysm filling at follow-up, absolute rates of retreatment at international and North American sites were similar by 2-year follow-up.

CONCLUSIONS

Data from the Matrix and Platinum Science Trial demonstrate that aneurysm retreatment occurs with different frequency and at different times in different regions of the world. This trend has critical value when interpreting trials reporting short-term outcomes, especially when judgment-based metrics such as retreatment are primary end points that may or may not take place within the defined study follow-up period. Though these variations can be controlled for and balanced within a given randomized trial, such differences in practice patterns must be accounted for in any attempt to compare outcomes between different trials. Despite these differences, endovascular-treated intracranial aneurysms around the world have similar clinical outcomes.

Endovascular Treatment of Incidental Cerebral Aneurysms

One hundred and fifteen patients with 120 intracranial incidental aneurysms were embodied using the GDC endovascular technique at UCLA Medical Center.

Angiographic results showed complete or near complete aneurysm occlusion in 109 aneurysms (91%) and an incomplete occlusion in five aneurysms (4%). An unsuccessful GDC embolization was attempted in six aneurysms (5%).

One hundred and nine patients (94.8%) remained neurologically intact or unchanged from initial clinical status. Five patients (43%) deteriorated due to immediate procedural complications. All these complications occurred in the first 50 patients. No clinical complications were observed in the last 65 patients. In Groups 1 and 3, the average length of hospitalization was 3.3 days.

The technical evolution of the GDC technology has proved to be safe for the treatment of incidental aneurysms (0% morbidity in the last 65 patients). The topography of the aneurysm/s and the clinical condition of the patient did not influence final anatomical or clinical outcomes. GDC technology also brings a positive economical impact by decreasing hospitalization time and eliminating postembolization ICU care.

Highly sensitive fluorescence detection of metastatic lymph nodes of gastric cancer with photo-oxidation of protoporphyrin IX

BACKGROUND

The establishment of a precise and rapid method to detect metastatic lymph nodes (LNs) is essential to perform less invasive surgery with reduced gastrectomy along with reduced lymph node dissection. We herein describe a novel imaging strategy to detect 5-aminolevulinic acid (5-ALA)-induced protoporphyrin IX (PpIX) fluorescence in excised LNs specifically with reduced effects of tissue autofluorescence based on photo-oxidation of PpIX. We applied the method in a clinical setting, and evaluated its feasibility.

METHODS

To reduce the unfavorable effect of autofluorescence, we focused on photo-oxidation of PpIX: Following light irradiation, PpIX changes into another substance, photo-protoporphyrin, via an oxidative process, which has a different spectral peak, at 675 nm, whereas PpIX has its spectral peak at 635 nm. Based on the unique spectral alteration, fluorescence spectral imaging before and after light irradiation and subsequent originally-developed image processing was performed. Following in vitro study, we applied this method to a total of 662 excised LNs obtained from 30 gastric cancer patients administered 5-ALA preoperatively.

RESULTS

Specific visualization of PpIX was achieved in in vitro study. The method allowed highly sensitive detection of metastatic LNs, with sensitivity of 91.9% and specificity of 90.8% in the in vivo clinical trial. Receiver operating characteristic analysis indicated high diagnostic accuracy, with the area under the curve of 0.926.

CONCLUSIONS

We established a highly sensitive and specific 5-ALA-induced fluorescence imaging method applicable in clinical settings. The novel method has a potential to become a useful tool for intraoperative rapid diagnosis of LN metastasis.

L-Arginine ethylester enhances in vitro amplification of PrP(Sc) in macaques with atypical L-type bovine spongiform encephalopathy and enables presymptomatic detection of PrP(Sc) in the bodily fluids

Protease-resistant, misfolded isoforms (PrP(Sc)) of a normal cellular prion protein (PrP(C)) in the bodily fluids, including blood, urine, and saliva, are expected to be useful diagnostic markers of prion diseases, and nonhuman primate models are suited for performing valid diagnostic tests for human Creutzfeldt-Jakob disease (CJD). We developed an effective amplification method for PrP(Sc) derived from macaques infected with the atypical L-type bovine spongiform encephalopathy (L-BSE) prion by using mouse brain homogenate as a substrate in the presence of polyanions and L-arginine ethylester. This method was highly sensitive and detected PrP(Sc) in infected brain homogenate diluted up to 10(10) by sequential amplification. This method in combination with PrP(Sc) precipitation by sodium phosphotungstic acid is capable of amplifying very small amounts of PrP(Sc) contained in the cerebrospinal fluid (CSF), saliva, urine, and plasma of macaques that have been intracerebrally inoculated with the L-BSE prion. Furthermore, PrP(Sc) was detectable in the saliva or urine samples as well as CSF samples obtained at the preclinical phases of the disease. Thus, our novel method may be useful for furthering the understanding of bodily fluid leakage of PrP(Sc) in nonhuman primate models.

Can sliding-window correlations reveal dynamic functional connectivity in resting-state fMRI?

During the last several years, the focus of research on resting-state functional magnetic resonance imaging (fMRI) has shifted from the analysis of functional connectivity averaged over the duration of scanning sessions to the analysis of changes of functional connectivity within sessions. Although several studies have reported the presence of dynamic functional connectivity (dFC), statistical assessment of the results is not always carried out in a sound way and, in some studies, is even omitted. In this study, we explain why appropriate statistical tests are needed to detect dFC, we describe how they can be carried out and how to assess the performance of dFC measures, and we illustrate the methodology using spontaneous blood-oxygen level-dependent (BOLD) fMRI recordings of macaque monkeys under general anesthesia and in human subjects under resting-state conditions. We mainly focus on sliding-window correlations since these are most widely used in assessing dFC, but also consider a recently proposed non-linear measure. The simulations and methodology, however, are general and can be applied to any measure. The results are twofold. First, through simulations, we show that in typical resting-state sessions of 10 min, it is almost impossible to detect dFC using sliding-window correlations. This prediction is validated by both the macaque and the human data: in none of the individual recording sessions was evidence for dFC found. Second, detection power can be considerably increased by session- or subject-averaging of the measures. In doing so, we found that most of the functional connections are in fact dynamic. With this study, we hope to raise awareness of the statistical pitfalls in the assessment of dFC and how they can be avoided by using appropriate statistical methods.

High-Resolution C-Arm CT and Metal Artifact Reduction Software: A Novel Imaging Modality for Analyzing Aneurysms Treated with Stent-Assisted Coil Embolization

BACKGROUND AND PURPOSE

Combination of high-resolution C-arm CT and novel metal artifact reduction software may contribute to the assessment of aneurysms treated with stent-assisted coil embolization. This study aimed to evaluate the efficacy of a novel Metal Artifact Reduction prototype software combined with the currently available high spatial-resolution C-arm CT prototype implementation by using an experimental aneurysm model treated with stent-assisted coil embolization.

MATERIALS AND METHODS

Eight experimental aneurysms were created in 6 swine. Coil embolization of each aneurysm was performed by using a stent-assisted technique. High-resolution C-arm CT with intra-arterial contrast injection was performed immediately after the treatment. The obtained images were processed with Metal Artifact Reduction. Five neurointerventional specialists reviewed the image quality before and after Metal Artifact Reduction. Observational and quantitative analyses (via image analysis software) were performed.

RESULTS

Every aneurysm was successfully created and treated with stent-assisted coil embolization. Before Metal Artifact Reduction, coil loops protruding through the stent lumen were not visualized due to the prominent metal artifacts produced by the coils. These became visible after Metal Artifact Reduction processing. Contrast filling in the residual aneurysm was also visualized after Metal Artifact Reduction in every aneurysm. Both the observational (P < .0001) and quantitative (P < .001) analyses showed significant reduction of the metal artifacts after application of the Metal Artifact Reduction prototype software.

CONCLUSIONS

The combination of high-resolution C-arm CT and Metal Artifact Reduction enables differentiation of the coil mass, stent, and contrast material on the same image by significantly reducing the metal artifacts produced by the platinum coils. This novel image technique may improve the assessment of aneurysms treated with stent-assisted coil embolization.

Hand-assisted laparoscopic transhiatal esophagectomy with a systematic procedure for en bloc infracarinal lymph node dissection

Laparoscopic transhiatal esophagectomy is a minimally invasive approach for esophageal cancer. However, a transhiatal procedure has not yet been established for en bloc mediastinal dissection. The purpose of this study was to present our novel procedure, hand-assisted laparoscopic transhiatal esophagectomy, with a systematic procedure for en bloc mediastinal dissection. The perioperative outcomes of patients who underwent this procedure were retrospectively analyzed. Transhiatal subtotal mobilization of the thoracic esophagus with en bloc lymph node dissection distally from the carina was performed according to a standardized procedure using a hand-assisted laparoscopic technique, in which the operator used a long sealing device under appropriate expansion of the operative field by hand assistance and long retractors. The thoracoscopic procedure was performed for upper mediastinal dissection following esophageal resection and retrosternal stomach roll reconstruction, and was avoided based on the nodal status and operative risk. A total of 57 patients underwent surgery between January 2012 and June 2013, and the transthoracic procedure was performed on 34 of these patients. In groups with and without the transthoracic procedure, total operation times were 370 and 216 minutes, blood losses were 238 and 139 mL, and the numbers of retrieved nodes were 39 and 24, respectively. R0 resection rates were similar between the groups. The incidence of recurrent laryngeal nerve palsy was significantly higher in the group with the transthoracic procedure, whereas no significant differences were observed in that of pneumonia between these groups. The hand-assisted laparoscopic transhiatal method, which is characterized by a systematic procedure for en bloc mediastinal dissection supported by hand and long device use, was safe and feasible for minimally invasive esophagectomy.

Perioperative outcomes of esophagectomy preceded by the laparoscopic transhiatal approach for esophageal cancer

This study was designed to determine the efficacy of esophagectomy preceded by the laparoscopic transhiatal approach (LTHA) with regard to the perioperative outcomes of esophageal cancer. The esophageal hiatus was opened by hand-assisted laparoscopic surgery, and carbon dioxide was introduced into the mediastinum. Dissection of the distal esophagus was performed up to the level of the tracheal bifurcation. En bloc dissection of the posterior mediastinal lymph nodes was performed using LTHA. Next, cervical lymphadenectomy, reconstruction via a retrosternal route with a gastric tube and anastomosis from a cervical approach were performed. Finally, a small thoracotomy (around 10 cm in size) was made to extract the thoracic esophagus and allow upper mediastinal lymphadenectomy to be performed. The treatment outcomes of 27 esophageal cancer patients who underwent LTHA-preceding esophagectomy were compared with those of 33 patients who underwent the transthoracic approach preceding esophagectomy without LTHA (thoracotomy; around 20 cm in size). The intrathoracic operative time and operative bleeding were significantly decreased by LTHA. The total operative time did not differ between the two groups, suggesting that the abdominal procedure was longer in the LTHA group. The number of resected lymph nodes did not differ between the two groups. Postoperative respiratory complications occurred in 18.5% of patients treated with LTHA and 30.3% of those treated without it. The increase in the number of peripheral white blood cells and the duration of thoracic drainage were significantly decreased by this method. Our surgical procedure provides a good surgical view of the posterior mediastinum, markedly shortens the intrathoracic operative time, and decreases the operative bleeding without increasing major postoperative complications.

Temporal correlation between wall shear stress and in-stent stenosis after Wingspan stent in swine model

BACKGROUND AND PURPOSE

A recent randomized clinical trial on intracranial atherosclerosis was discontinued because of the higher frequency of stroke and death in the angioplasty and stent placement group than in the medical treatment group. An in-depth understanding of the relationship between biologic responses and flow dynamics is still required to identify the current limitations of intracranial stent placement.

MATERIALS AND METHODS

Five Wingspan stents were deployed in tapered swine ascending pharyngeal arteries. Temporal wall shear stress distributions and in-stent stenosis were evaluated at days 0, 7, 14, and 28 after stent placement. The physiologic role of wall shear stress was analyzed regarding its correlation with in-stent stenosis.

RESULTS

In-stent stenosis reached a peak of nearly 40% at day 14 and decreased mainly at the distal stent segment until day 28. The wall shear stress demonstrated a characteristic pattern with time on the basis of the in-stent stenosis change. The wall shear stress gradient increased from the proximal to distal segment until day 14. At day 28, the trend was reversed dramatically, decreasing from the proximal to the distal segment. A significant correlation between the in-stent stenosis growth until day 14 and low wall shear stress values just after stent placement was detected. In-stent stenosis regression between days 14 and 28 was also associated with the high wall shear stress values at day 14.

CONCLUSIONS

These data suggest that the physiologic wall shear stress can control the biphasic in-stent stenosis change in tapered arteries.

Natural course of dissecting vertebrobasilar artery aneurysms without stroke

BACKGROUND AND PURPOSE

The natural history and therapeutic management of dissecting vertebrobasilar aneurysms without ischemic or hemorrhagic stroke (nonstroke dissecting vertebrobasilar aneurysms) are not well-established. We conservatively followed patients with nonstroke dissecting vertebrobasilar aneurysms and evaluated the factors related to clinical and morphologic deterioration.

MATERIALS AND METHODS

One hundred thirteen patients were enrolled and divided by clinical presentation at diagnosis: asymptomatic (group 1, n = 52), pain only (group 2, n = 56), and mass effect (group 3, n = 5). Patients were conservatively managed without intervention and antithrombotic therapy. Clinical outcomes and morphologic changes were analyzed.

RESULTS

A total of 113 patients who were diagnosed with nonstroke dissecting vertebrobasilar aneurysm had a mean follow-up of 2.9 years (range, 27 days to 8 years). Throughout that period, 1 patient in group 1 (1.9%) and 1 patient in group 2 (1.8%) showed clinical deterioration due to mass effect, and 1 patient in group 3 (20%) developed ischemic stroke followed by subarachnoid hemorrhage. Most patients (97.3%) were clinically unchanged. Three patients who had clinical deterioration showed aneurysm enlargement (P < .001). Aneurysms remained morphologically unchanged in 91 patients (80.5%). Aneurysm enlargement was seen in 5 patients (4.4%); risk of enlargement was significantly associated with either maximum diameter (hazard ratio = 1.30; 95% CI, 1.11-11.52; P = .001) or aneurysm ≥10 mm (hazard ratio = 18.0; 95% CI, 1.95-167; P = .011).

CONCLUSIONS

The natural course of these lesions suggests that acute intervention is not always required and close follow-up without antithrombotic therapy is reasonable. Patients with symptoms due to mass effect or aneurysms of >10 mm may require treatment.

Validation and initial application of a semiautomatic aneurysm measurement software: a tool for assessing volumetric packing attenuation

BACKGROUND AND PURPOSE

Precise aneurysm measurements and volume embolization ratios are essential for long-term durability of endovascular coil embolization. We evaluated the accuracy of newly developed semiautomatic cerebral aneurysm measurement software, NeuroVision, and explored the value of volume embolization ratio in the prediction of re-treatment.

MATERIALS AND METHODS

We compared software-derived volume measurements of 4 silicone aneurysm models with those calculated with an approximation formula and ground truth values (validation study). We used NeuroVision to retrospectively evaluate outcomes of 100 unruptured aneurysms (97 patients) treated with embolization (clinical study). Aneurysm size (height, width, and neck), volume, and volume embolization ratios were calculated for 3 groups (stable, recanalization, and re-treatment) and were compared.

RESULTS

This validation study illustrated higher accuracy of NeuroVision in computing aneurysm volume compared with an approximation formula: percentage absolute errors were 4.50% ± 3.18% and 23.07% ± 17.60%, with maximal percentage absolute errors of 8.99% and 45.63%, respectively. Of 100 unruptured aneurysms, 20 recanalized and 12 were re-treated. Average volume embolization ratios of stable and re-treated aneurysms were 24.88% ± 5.91% and 20.50% ± 4.06%, respectively (P ≤ .01). The optimal volume embolization ratio cutoff point for re-treatment was < 19.15%, at which the Youden index was 0.50 (sensitivity, 58.33%; specificity, 87.50%; area under the receiver operating characteristic curve, 0.74).

CONCLUSIONS

The NeuroVision software provided accurate aneurysm volume measurements and may be a useful standardized tool to measure aneurysm size and volume, especially for multicenter clinical studies. Volume embolization ratio may be a valuable predictor of aneurysm occlusion changes.

Stent-assisted coiling versus coiling alone in unruptured intracranial aneurysms in the matrix and platinum science trial: safety, efficacy, and mid-term outcomes

BACKGROUND AND PURPOSE

Stent-assisted coiling may result in less aneurysm recanalization but more complications than coiling alone. We evaluated outcomes of coiling with and without stents in the multicenter Matrix and Platinum Science Trial.

MATERIALS AND METHODS

All patients in the Matrix and Platinum Science Trial with unruptured intracranial aneurysms treated per protocol were included. Baseline patient and aneurysm characteristics, procedural details, neurologic outcomes, angiographic outcomes, and safety data were analyzed.

RESULTS

Overall, 137 of 361 (38%) patients were treated with a stent. Stent-coiled aneurysms had wider necks (≥4 mm in 62% with stents versus 33% without, P < .0001) and lower dome-to-neck ratios (1.3 versus 1.8, P < .0001). Periprocedural serious adverse events occurred infrequently in those treated with and without stents (6.6% versus 4.5%, P = .39). At 1 year, total significant adverse events, mortality, and worsening of mRS were similar in treatment groups, but ischemic strokes were more common in stent-coiled patients than in coiled patients (8.8% versus 2.2%, P = .005). However, multivariate analysis confirmed that at 2 years after treatment, prior cerebrovascular accident (OR, 4.7; P = .0089) and aneurysm neck width ≥4 mm (OR, 4.5; P = .02) were the only independent predictors of ischemic stroke. Stent use was not an independent predictor of ischemic stroke at 2 years (OR, 1.1; P = .94). Stent use did not predict target aneurysm recurrence at 2 years, but aneurysm dome size ≥10 mm (OR, 9.94; P < .0001) did predict target aneurysm recurrence.

CONCLUSIONS

Stent-coiling had similar outcomes as coiling despite stented aneurysms having more difficult morphology than coiled aneurysms. Increased ischemic events in stent-coiled aneurysms were attributable to baseline risk factors and aneurysm morphology.

A fluid-structure interaction study using patient-specific ruptured and unruptured aneurysm: the effect of aneurysm morphology, hypertension and elasticity

Fluid-structure interaction (FSI) simulations using five patient-specific aneurysm geometries are carried out to investigate the difference between ruptured and unruptured aneurysms. Two different blood pressure conditions (normal and hypertension, for all cases), and two different values of elastic modulus (1 and 2MPa, for two cases) are tested. Ruptured aneurysms (RA) generally displayed larger displacement at the dome, lower area-average WSS and higher von Mises stress than unruptured aneurysms (URA) regardless of elasticity or blood pressure condition. RAs had a longitudinal expansion whereas URAs had a radial expansion, which was the key difference between the two types. The difference in expansion pattern may be one of the keys to explaining aneurysm rupture, and further analysis is required in the future to confirm this theory.

Human amnion-derived cells as a reliable source of stem cells

Human amnion-derived cells possess great potential for the repair of human neural disorders, and recent studies have broadened the spectrum for applications because they exhibit the characteristics of multipotent stem cells. These cells express embryonic stem cell markers such as Oct4, Nanog, Sox2, SSEA-3, SSEA-4 and Rex1, and can differentiate into multiple primary germ layers both in vitro and in vivo. Moreover, induced pluripotent stem cells have been generated from amnion-derived cells by virus-mediated delivery of three or four pluripotency-relating transcription factors or by the introduction of only one transcription factor with electroporation. Because human amnion-derived cells are readily available, less likely to contain genetic aberrations and can be reprogrammed earlier and more efficiently than differentiated cells, they can be ideal resources as the donor pluripotent stem cells for therapeutic purposes. We discuss here the highlights of recent studies and potential applications of human amnion-derived multipotent stem cells to stem cell biology as well as to regenerative medicine in the field of aging, heart disease, diabetes and neural disorders.

The influence of elastic upstream artery length on fluid-structure interaction modeling: a comparative study using patient-specific cerebral aneurysm

Fluid-structure interaction (FSI) simulations using a patient-specific geometry are carried out to investigate the influence the length of elastic parent artery and the position of constraints in the solid domain on the accuracy of patient-specific FSI simulations. Three models are tested: Long, Moderate, and Short, based on the length of the elastic parent artery. All three models use same wall thickness (0.5 mm) and the elastic modulus (5 MPa). The maximum mesh displacement is the largest for the Long model (0.491 mm) compared to other models (0.3 mm for Moderate, and 0.132 mm for Short). The differences of hemodynamic and mechanical variables, aneurysm volume and cross-sectional area between three models are all found to be minor. In addition, the Short model takes the least amount of computing time of the three models (11h compared to 21 h for Long and 19 h for Moderate). The present results indicate that the use of short elastic upstream artery can shorten the time required for pati ent-specific FSI simulations without impacting the overall accuracy of the results.

Justification of unruptured intracranial aneurysm repair: a single-center experience

BACKGROUND AND PURPOSE

Whether to treat UIAs is controversial. The aim of the study was to compare the clinical outcome of patients with UIAs who were either treated conservatively or preventively.

MATERIALS AND METHODS

Patients with UIAs referred to our institution were prospectively enrolled in the study. Data collected included baseline characteristics, aneurysmal features, and procedural and follow-up information. Preventive treatment was recommended if the aneurysm was larger than 5 mm and was considered safely treatable. Endovascular surgery was the first-line therapy if the aneurysmal shape was appropriate for coiling.

RESULTS

From January 2003 through April 2008, a total of 879 patients with 1110 UIAs were enrolled; 325 patients with 369 UIAs (mean size, 7.8 mm) were treated (treatment group), and 603 patients with 741 UIAs (mean size, 4.4 mm) were managed conservatively (observation group). Mean follow-up was 692.5 days (1405.5 person-years). In the observation group, 26 aneurysms (3.5%) had ruptured (1.8% per year; 1405.5 person-years), 10 patients died, and 7 were disabled (mRS, 3-6: 2.8%). Aneurysmal size was a significant risk factor for rupture (P = .001). The treatment group included aneurysms treated either with coiling (n=315), clipping (n=32), or a combined approach (n=9); 1 patient died, and 3 were disabled (mRS, 3-6: 1.2%). Therapeutic intervention was equal (UIAs of all sizes) or superior (UIAs > 5 mm; P = .025) to conservative management.

CONCLUSIONS

Treatment of UIAs was justified in aneurysms larger than 5 mm, and EVS can be safely applied to nearly 90% of UIAs.

A swine model to analyze arterial structural changes induced by mechanical thrombectomy

We report a novel swine model that allows direct visualization of cervical arteries undergoing mechanical thrombectomy. The model also facilitates evaluation of histologic changes observed in the arteries after treatment. Swine superficial cervical arteries, which are similar in size and branching pattern to the human middle cerebral artery, were surgically exposed, occluded with experimental thrombus, and subsequently treated with the Merci clot retriever device. Angiographic and histologic assessment were performed.