Integrated metagenomic and metabolomic analysis reveals distinctive stage-specific gut-microbiome-derived metabolites in intracranial aneurysms.

OBJECTIVE: Our study aimed to explore the influence of gut microbiota and their metabolites on intracranial aneurysms (IA) progression and pinpoint-related metabolic biomarkers derived from the gut microbiome. DESIGN: We recruited 358 patients with unruptured IA (UIA) and 161 with ruptured IA (RIA) from two distinct geographical regions for conducting an integrated analysis of plasma metabolomics and faecal metagenomics. Machine learning algorithms were employed to develop a classifier model, subsequently validated in an independent cohort. Mouse models of IA were established to verify the potential role of the specific metabolite identified. RESULTS: Distinct shifts in taxonomic and functional profiles of gut microbiota and their related metabolites were observed in different IA stages. Notably, tryptophan metabolites, particularly indoxyl sulfate (IS), were significantly higher in plasma of RIA. Meanwhile, upregulated tryptophanase expression and indole-producing microbiota were observed in gut microbiome of RIA. A model harnessing gut-microbiome-derived tryptophan metabolites demonstrated remarkable efficacy in distinguishing RIA from UIA patients in the validation cohort (AUC=0.97). Gut microbiota depletion by antibiotics decreased plasma IS concentration, reduced IA formation and rupture in mice, and downregulated matrix metalloproteinase-9 expression in aneurysmal walls with elastin degradation reduction. Supplement of IS reversed the effect of gut microbiota depletion. CONCLUSION: Our investigation highlights the potential of gut-microbiome-derived tryptophan metabolites as biomarkers for distinguishing RIA from UIA patients. The findings suggest a novel pathogenic role for gut-microbiome-derived IS in elastin degradation in the IA wall leading to the rupture of IA.

A comprehensive analysis of patients with cerebral arteriovenous malformation with headache: assessment of risk factors and treatment effectiveness.

BACKGROUND: Due to the high mortality and disability rate of intracranial hemorrhage, headache is not the main focus of research on cerebral arteriovenous malformation (AVM), so research on headaches in AVM is still scarce, and the clinical understanding is shallow. This study aims to delineate the risk factors associated with headaches in AVM and to compare the effectiveness of various intervention treatments versus conservative treatment in alleviating headache symptoms. METHODS: This study conducted a retrospective analysis of AVMs who were treated in our institution from August 2011 to December 2021. Multivariable logistic regression analysis was employed to assess the risk factors for headaches in AVMs with unruptured, non-epileptic. Additionally, the effectiveness of different intervention treatments compared to conservative management in alleviating headaches was evaluated through propensity score matching (PSM). RESULTS: A total of 946 patients were included in the analysis of risk factors for headaches. Multivariate logistic regression analysis identified that female (OR 1.532, 95% CI 1.173-2.001, p = 0.002), supply artery dilatation (OR 1.423, 95% CI 1.082-1.872, p = 0.012), and occipital lobe (OR 1.785, 95% CI 1.307-2.439, p < 0.001) as independent risk factors for the occurrence of headaches. There were 443 AVMs with headache symptoms. After propensity score matching, the microsurgery group (OR 7.27, 95% CI 2.82-18.7 p < 0.001), stereotactic radiosurgery group(OR 9.46, 95% CI 2.26-39.6, p = 0.002), and multimodality treatment group (OR 8.34 95% CI 2.87-24.3, p < 0.001) demonstrate significant headache relief compared to the conservative group. However, there was no significant difference between the embolization group (OR 2.24 95% CI 0.88-5.69, p = 0.091) and the conservative group. CONCLUSIONS: This study identified potential risk factors for headaches in AVMs and found that microsurgery, stereotactic radiosurgery, and multimodal therapy had significant benefits in headache relief compared to conservative treatment. These findings provide important guidance for clinicians when developing treatment options that can help improve overall treatment outcomes and quality of life for patients.

Efficacy and safety of flow diverter combined with coil embolization and evidence-based antithrombotic regimen in the treatment of ruptured aneurysms.

OBJECTIVE: The use of a flow diverter (FD) in the treatment of ruptured aneurysms is limited due to the increased risk of perioperative ischemia and hemorrhagic complications. Adjunctive coil embolization and an evidence-based antithrombotic regimen may improve therapeutic safety, although evidence from relevant clinical research is limited. The authors' aim was to further assess the perioperative safety and long-term efficacy of this strategy. METHODS: Data on patients with FD insertion and coil embolization were collected retrospectively at two centers. The perioperative antithrombotic regimen consists of intraoperative tirofiban and continues for 24 hours postoperatively, with the initiation of an orally administered dual-antiplatelet regimen 4 hours prior to tirofiban cessation, rather than purposeful preoperative antiplatelet therapy. Perioperative cerebral ischemia and hemorrhagic complications and long-term aneurysm occlusion rates were recorded to evaluate the safety and efficacy of the procedure, respectively. RESULTS: In total, 67 cases were screened and 41 cases were ultimately included in this study. A total of 2 cases (4.9%) of perioperative cerebral hemorrhagic events occurred, 1 of which (2.4%) was attributable to rerupture of the aneurysm. Cerebral ischemic events were reported in 3 patients, including 1 with cortical thromboembolism and 2 with perforator occlusion of the basilar artery. A median 8-month follow-up was attained in 25 patients (61.0%), with a 92% complete or near-complete occlusion rate. CONCLUSIONS: FD insertion combined with coil embolization is a potentially safe and effective therapeutic strategy for ruptured aneurysms when accompanied with perioperative evidence-based antithrombotic therapy.

Comparison of 7 T and 3 T vessel wall MRI for the evaluation of intracranial aneurysm wall.

OBJECTIVES: To compare the visibility of intracranial aneurysm wall and thickness quantification between 7 and 3 T vessel wall imaging and evaluate the association between aneurysm size and wall thickness. METHODS: Twenty-nine patients with 29 unruptured intracranial aneurysms were prospectively recruited for 3D T1-weighted vessel wall MRI at both 3 T and 7 T with 0.53 mm (3 T) and 0.4 mm (7 T) isotropic resolution, respectively. Two neuroradiologists independently evaluated wall visibility (0-5 Likert scale), quantified the apparent wall thickness (AWT) using a semi-automated full-width-half-maximum method, calculated wall sharpness, and measured the wall-to-lumen contrast ratio (CRwall/lumen). RESULTS: Twenty-four patients with 24 aneurysms were included in this study. 7 T achieved significantly better aneurysm wall visibility than 3 T (3.6 ± 1.1 vs 2.7 ± 0.8, p = 0.003). AWT measured on 3 T and 7 T had a good correlation (averaged r = 0.63 ± 0.19). However, AWT on 3 T was 15% thicker than that on 7 T (0.52 ± 0.07 mm vs 0.45 ± 0.05 mm, p < 0.001). Wall sharpness on 7 T was 57% higher than that on 3 T (1.95 ± 0.32 mm-1 vs 1.24 ± 0.15 mm-1, p < 0.001). CRwall/lumen on 3 T and 7 T was comparable (p = 0.424). AWT on 7 T was positively correlated with aneurysm size (saccular: r = 0.58, q = 0.046; fusiform: r = 0.67, q = 0.049). CONCLUSIONS: 7 T provides better visualization of intracranial aneurysm wall with higher sharpness than 3 T. 3 T overestimates the wall thickness relative to 7 T. Aneurysm wall thickness is positively correlated with aneurysm size. 7 T MRI is a promising tool to evaluate aneurysm wall in vivo. KEY POINTS: • 7 T provides better visualization of intracranial aneurysm wall with higher sharpness than 3 T. • 3 T overestimates the wall thickness comparing with 7 T. • Aneurysm wall thickness is positively correlated with aneurysm size.

Elevated blood hemoglobin on admission as an independent predictor of unfavorable outcomes in patients with aneurysmal subarachnoid hemorrhage.

Hemoglobin (HGB), a potent spasmogen, may cause irreversible damage to the brain after aneurysm rupture. However, there is no clinical evidence to reveal the relationship between blood HGB concentrations on admission and the prognosis of patients with aneurysmal subarachnoid hemorrhage (aSAH). We retrospectively reviewed all aSAH patients admitted to our institution between January 2015 and December 2020. Functional outcome was assessed at 90 days after discharge using the modified Rankin scale (mRS). Independent risk factors associated with 90-day unfavorable outcomes were derived from a forward stepwise multivariate analysis. Receiver operating characteristic curve analysis was conducted to identify the best cutoff value of HGB to discriminate 90-day unfavorable outcomes. Then, patients were divided into two groups according to the cutoff value of HGB, and to account for imbalances in baseline characteristics, propensity score matching (PSM) was carried out to assess the impact of HGB on in-hospital complications. A total of 800 aSAH patients without anemia on admission were retrospectively enrolled in this study. Elevated blood HGB (OR = 1.02, 95% CI = 1.00-1.03, p = 0.018) on admission was identified as an independent risk factor associated with 90-day unfavorable outcomes, and the cutoff value was 149.5 g/L. After PSM, patients with an HGB > 149.5 g/L had a higher incidence of in-hospital delayed cerebral ischemia (DCI) (33.9% vs. 22.0%, p = 0.013) and deep vein thrombosis (DVT) (11.9% vs. 4.0%, p = 0.006). Patients with a blood HGB > 149.5 g/L on admission might develop more DCI and DVT during hospitalization, leading to 90-day unfavorable outcomes in aSAH patients. ClinicalTrials.gov Identifier: NCT04785976. 2021/03/05, retrospectively registered.

The effect of sex differences on complications and 90-day outcomes after aneurysmal subarachnoid hemorrhage: a propensity score-matched analysis.

Aneurysmal subarachnoid hemorrhage (aSAH) is the most devastating form of stroke. Up to now, little is known about the effect of sex differences on complications and outcomes. We retrospectively reviewed aSAH patients admitted to our institution between January 2015 and December 2020. The functional outcomes at discharge and 90 days after discharge were assessed using the modified Rankin Scale (mRS). Baseline characteristics, in-hospital complications, and outcomes were compared after 1:1 propensity score matching (PSM). The area under the curve (AUC) in the receiver operating characteristic curve (ROC) analysis was calculated to measure each independent risk factor's prediction ability. A total of 833 patients were included. After PSM, 109 male patients were compared with 109 female patients. Female patients had a higher incidence of anemia (47/109 [43.1%] vs. 30/109 [27.5%], p = 0.016) than male patients, while male patients had a higher incidence of pneumonia (36/109 [33.0%] vs. 19/109 [17.4%], p = 0.008) than female patients. No significant differences were found in the rate of unfavorable outcomes at discharge and 90-day outcomes (40/109 [36.7%] vs. 50/109 [45.9%], p = 0.169; 15/109 [13.8%] vs. 19/107 [17.8%], p = 0.420) between female and male patients. Pneumonia (AUC = 0.749, 95% confidence interval [CI] = 0.623-0.875, p < 0.001) and anemia (AUC = 0.753, 95% CI = 0.632-0.873, p = 0.002) showed good ability to predict 90-day unfavorable outcomes in male and female patients, respectively. Female patients had a higher incidence of anemia but a lower incidence of pneumonia during hospitalization. However, differences in in-hospital complications did not result in differences in outcomes between women and men. Clinical Trial Registration: NCT04785976. 2021/03/05, retrospectively registered.

Identification of intra-individual variation in intracranial arterial flow by MRI and the effect on computed hemodynamic descriptors.

OBJECTIVES: To determine the intra-individual flow variation in serially acquired studies, and the influence of this variation on subsequent hemodynamic simulations using the inlet flow as a boundary condition. Author: Kindly check and confirm whether the corresponding authors are correctly identified.Confirmed. MATERIALS AND METHODS: This prospective study included 51 patients (37 females and 14 males) with unruptured intracranial aneurysms who have received more than three times follow-up of 2D phase-contrast MR. The flow and velocity parameters were extracted to calculate the reproducibility and variation. Patient-specific computational fluid dynamics simulations were performed using the measured flows. RESULTS: Intraclass correlation coefficients for mean and maximum velocity and flow parameters ranged from 0.77 to 0.90. A 10% CV of mean flow was identified. Variations of 10% in inlet flow resulted in hemodynamic changes including 41.41% of peak systolic wall shear stress; 39.13% of end-diastolic wall shear stress; 2.79% of low shear area at peak systole; 2.12% of low shear area at end diastole: 47.57% of time-averaged wall shear stress; and 0.17% of oscillatory shear index. CONCLUSION: This study identified 10% of intra-individual mean flow variation on phase-contrast MR. Intra-individual flow variation resulted in a non-negligible variation in wall shear stress, but relatively small variation in low shear area in hemodynamic calculations.

Wall enhancement of intracranial saccular and fusiform aneurysms may differ in intensity and extension: a pilot study using 7-T high-resolution black-blood MRI.

PURPOSE: To evaluate and compare wall enhancement patterns in saccular and fusiform intracranial aneurysms using high-resolution black-blood MRI at 7 T. METHODS: Thirty-one patients with 32 unruptured intracranial aneurysms (21 saccular and 11 fusiform) underwent 7-T black-blood MRI. Aneurysm wall enhancement (AWE) was categorized as follows: no wall enhancement (NWE), focal wall enhancement (FWE), and uniform wall enhancement (UWE). The degree of enhancement was scored as follows: 0 (no enhancement), 1 (signal intensity (SI) of the aneurysm wall less than that of the pituitary infundibulum), and 2 (equal to that of the pituitary infundibulum). The chi-squared test was used to compare the AWE pattern and degree between saccular and fusiform aneurysms. RESULTS: In saccular aneurysms, 12/21 (57%) enhanced. Of these, 9 showed FWE (5 grade 1 and 4 grade 2), and 3 showed UWE (2 grade 1 and 1 grade 2). In fusiform aneurysms, 11/11 (100%) enhanced. Of these, 1 showed FWE and 10 showed UWE. All fusiform aneurysms had grade-2 enhancement. Fusiform aneurysms had more extensive and higher SI AWE than saccular aneurysms (p < 0.01) despite having a similar size (6.9 ± 3.0 mm vs. 8.0 ± 2.9, p = 0.23). For saccular aneurysm, larger aneurysm size was correlated with higher degree of enhancement with Pearson's r = 0.64 (p = 0.002). CONCLUSION: Intracranial fusiform aneurysms had enhancement of higher SI and that covered a more extensive area than saccular aneurysms, which might indicate differences in vessel wall pathology. KEY POINTS: • Intracranial aneurysm wall enhancement can be reliably characterized by 7-T black-blood MRI. • AWE in intracranial fusiform aneurysms presents over a larger surface area and with greater signal intensity as compared with that in saccular aneurysms, which might indicate differences in pathology. • Stronger signal intensity of AWE correlates with the aneurysm size in saccular aneurysms.

Prediction of Aneurysm Stability Using a Machine Learning Model Based on PyRadiomics-Derived Morphological Features.

Background and Purpose- Discrimination of the stability of intracranial aneurysms is critical for determining the treatment strategy, especially in small aneurysms. This study aims to evaluate the feasibility of applying machine learning for predicting aneurysm stability with radiomics-derived morphological features. Methods- Morphological features of 719 aneurysms were extracted from PyRadiomics, of which 420 aneurysms with Maximum3DDiameter ranging from 4 mm to 8 mm were enrolled for analysis. The stability of these aneurysms and other clinical characteristics were reviewed from the medical records. Based on the morphologies with/without clinical features, machine learning models were constructed and compared to define the morphological determinants and screen the optimal model for predicting aneurysm stability. The effect of clinical characteristics on the morphology of unstable aneurysms was analyzed. Results- Twelve morphological features were automatically extracted from PyRadiomics implemented in Python for each aneurysm. Lasso regression defined Flatness as the most important morphological feature to predict aneurysm stability, followed by SphericalDisproportion, Maximum2DDiameterSlice, and SurfaceArea. SurfaceArea (odds ratio [OR], 0.697; 95% CI, 0.476-0.998), SphericalDisproportion (OR, 1.730; 95% CI, 1.143-2.658), Flatness (OR, 0.584; 95% CI, 0.374-0.894), Hyperlipemia (OR, 2.410; 95% CI, 1.029-5.721), Multiplicity (OR, 0.182; 95% CI, 0.082-0.380), Location at middle cerebral artery (OR, 0.359; 95% CI, 0.134-0.902), and internal carotid artery (OR, 0.087; 95% CI, 0.030-0.211) were enrolled into the final prediction model. In terms of performance, the area under curve of the model reached 0.853 (95% CI, 0.767-0.940). For unstable aneurysms, Compactness1 (P=0.035), Compactness2 (P=0.036), Sphericity (P=0.035), and Flatness (P=0.010) were low, whereas SphericalDisproportion (P=0.034) was higher in patients with hypertension. Conclusions- Morphological features extracted from PyRadiomics can be used for aneurysm stratification. Flatness is the most important morphological determinant to predict aneurysm stability. Our model can be used to predict aneurysm stability. Unstable aneurysm is more irregular in patients with hypertension.

Efficacy of endovascular intervention in patients with unruptured posterior communicating artery aneurysm-related oculomotor nerve palsy.

OBJECTIVES: Oculomotor nerve palsy (ONP) is commonly encountered in daily neurosurgical activities. The ONP secondary to un-ruptured PComA aneurysm might be a unique entity that was different in diagnosis, treatment and prognosis from its ruptured counterparts. Perhaps as a result of the limitation in sample size, studies that solely focused on factors affecting recovery of ONP in patients with unruptured corresponding PComA aneurysms were scarce. METHODS: In this study, we would like to report a relatively larger case series of patients with un-ruptured PComA aneurysm-related ONP. A retrospective review of medical records of 39 patients with un-ruptured PComA aneurysm-related ONP was performed with endovascular coiling. RESULTS: All 39 consecutive patients underwent endovascular coiling. Eighteen (46%) patients had a complete resolution of ONP, 14 (36%) patients had a partial resolution. Time interval from onset of ONP to endovascular intervention (P=0.004), degree of ONP (P=0.015) and age (P=0.016) were predictors of ONP recovery with statistical significance. Sex, aneurysm size and risk factor exposure (smoking, alcohol abuse and hypertension) were not associated with ONP outcomes. CONCLUSION: ONP secondary to un-ruptured aneurysm should be treated as a unique entity from its ruptured counterparts. A prospective study that contains surgical clipping and endovascular coiling, and comparison between two treatment modalities would be more convincing and is anticipated.

Shear Stress Induces Phenotypic Modulation of Vascular Smooth Muscle Cells via AMPK/mTOR/ULK1-Mediated Autophagy.

Phenotypic modulation of vascular smooth muscle cells (VSMCs) is involved in the pathophysiological processes of the intracranial aneurysms (IAs). Although shear stress has been implicated in the proliferation, migration, and phenotypic conversion of VSMCs, the molecular mechanisms underlying these events are currently unknown. In this study, we investigated whether shear stress(SS)-induced VSMC phenotypic modulation was mediated by autophagy involved in adenosine monophosphate-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR)/Unc-51-like kinase 1 (ULK1) pathway. The results show that shear stress could inhibit the expression of key VSMC contractile genes and induce pro-inflammatory/matrix-remodeling genes levels, contributing to VSMCs phenotypic switching from a contractile to a synthetic phenotype. More importantly, Shear stress also markedly increased the levels of the autophagy marker microtubule-associated protein light chain 3-II (LC3II), Beclin-1, and p62 degradation. The autophagy inhibitor 3-methyladenine (3-MA) significantly blocked shear-induced phenotypic modulation of VSMCs. To further explore the molecular mechanism involved in shear-induced autophagy, we found that shear stress could activate AMPK/mTOR/ULK1 signaling pathway in VSMCs. Compound C, a pharmacological inhibitor of AMPK, significantly reduced the levels of p-AMPK and p-ULK, enhanced p-mTOR level, and finally decreased LC3II and Beclin-1 level, which suggested that activated AMPK/mTOR/ULK1 signaling was related to shear-mediated autophagy. These results indicate that shear stress promotes VSMC phenotypic modulation through the induction of autophagy involved in activating the AMPK/mTOR/ULK1 pathway.

Compensatory force measurement and multimodal force feedback for remote-controlled vascular interventional robot.

Minimally invasive vascular interventional surgery is widely used and remote-controlled vascular interventional surgery robots (RVIRs) are being developed to reduce the occupational risk of the intervening physician in minimally invasive vascular interventional surgeries. Skilled surgeon performs surgeries mainly depending on the detection of collisions. Inaccurate force feedback will be difficult for surgeons to perform surgeries or even results in medical accidents. In addition, the surgeon cannot quickly and easily distinguish whether the proximal force exceeds the safety threshold of blood vessels or not, and thus it results in damage to the blood vessels. In this paper, we present a novel method comprising compensatory force measurement and multimodal force feedback (MFF). Calibration experiments and performance evaluation experiments were carried out. Experimental results demonstrated that the proposed method can measure the proximal force of catheter/guidewire accurately and assist surgeons to distinguish the change of proximal force more easily. This novel method is suitable for use in actual surgical operations.

Study on real-time force feedback for a master-slave interventional surgical robotic system.

In robot-assisted catheterization, haptic feedback is important, but is currently lacking. In addition, conventional interventional surgical robotic systems typically employ a master-slave architecture with an open-loop force feedback, which results in inaccurate control. We develop herein a novel real-time master-slave (RTMS) interventional surgical robotic system with a closed-loop force feedback that allows a surgeon to sense the true force during remote operation, provide adequate haptic feedback, and improve control accuracy in robot-assisted catheterization. As part of this system, we also design a unique master control handle that measures the true force felt by a surgeon, providing the basis for the closed-loop control of the entire system. We use theoretical and empirical methods to demonstrate that the proposed RTMS system provides a surgeon (using the master control handle) with a more accurate and realistic force sensation, which subsequently improves the precision of the master-slave manipulation. The experimental results show a substantial increase in the control accuracy of the force feedback and an increase in operational efficiency during surgery.

A cooperation of catheters and guidewires-based novel remote-controlled vascular interventional robot.

Remote-controlled vascular interventional robots (RVIRs) are being developed to increase the overall accuracy of surgical operations and reduce the occupational risks of intervening physicians, such as radiation exposure and chronic neck/back pain. Several RVIRs have been used to operate catheters or guidewires accurately. However, a lack of cooperation between the catheters and guidewires results in the surgeon being unable to complete complex surgery by propelling the catheter/guidewire to the target position. Furthermore, it is a significant challenge to operate the catheter/guidewire accurately and detect their proximal force without damaging their surfaces. In this study, we introduce a novel method that allows catheters and guidewires to be operated simultaneously in complex surgery. Our method accurately captures force measurements and enables precisely controlled catheter and guidewire operation. A prototype is validated through various experiments. The results demonstrate the feasibility of the proposed RVIR to operate a catheter and guidewire accurately, detect the resistance forces, and complete complex surgical operations in a cooperative manner.

Transverse microvibrations-based guide wires drag reduction evaluation for endovascular interventional application.

When conducting endovascular interventional surgery, doctors usually experience high viscous resistance resulting from direct contact with blood when operating the guide wire in blood vessels, which reduces the operational efficiency. Improper operation can cause vascular injuries and greatly reduce surgical safety, sometimes leading to the death of the patient. This paper presents a new method that applies transverse microvibrations at the proximal end of a conventional passive guide wire to reduce viscous resistance. The effect of the proposed method in reducing the viscous resistance in the fluid is studied. The influences of the tube diameter, medium density, and applied vibration frequency on the viscous force are investigated. Finally, for endovascular therapy, a mathematical model of the viscous force of the guide wire based on the proposed method is established in the environment of human blood vessels to predict the magnitude of the viscous force exerted on the guide wire and analyze the drag reduction effect of the proposed method. The effectiveness of the proposed method in drag reduction and its feasibility in improving surgical safety are experimentally demonstrated. The experimental results indicate that the proposed method can assist the doctor during complicated and variable operation conditions.

Operating force information on-line acquisition of a novel slave manipulator for vascular interventional surgery.

Vascular interventional surgery has its advantages compared to traditional operation. Master-slave robotic technology can further improve the operation accuracy, efficiency and safety of this complicated and high risk surgery. However, on-line acquisition of operating force information of catheter and guidewire remains to be a significant obstacle on the path to enhancing robotic surgery safety. Thus, a novel slave manipulator is proposed in this paper to realize on-line sensing of guidewire torsional operating torque and axial operation force during robotic assisted operations. A strain sensor is specially designed to detect the small scale torsional operation torque with low rotational frequency. Additionally, the axial operating force is detected via a load cell, which is incorporated into a sliding mechanism to eliminate the influence of friction. For validation, calibration and performance evaluation experiments are conducted. The results indicate that the proposed operation torque and force detection device is effective. Thus, it can provide the foundation for enabling accurate haptic feedback to the surgeon to improve surgical safety.

Operation evaluation in-human of a novel remote-controlled vascular interventional robot.

Remote-controlled vascular interventional robots (RVIRs) are being developed to increase the accuracy of surgical operations and reduce the number of occupational risks sustained by intervening physicians, such as radiation exposure and chronic neck/back pain. However, complex control of the RVIRs improves the doctor's operation difficulty and reduces the operation efficiency. Furthermore, incomplete sterilization of the RVIRs will increase the risk of infection, or even cause medical accidents. In this study, we introduced a novel method that provides higher operation efficiency than a previous prototype and allows for complete robot sterilization. A prototype was fabricated and validated through laboratory setting experiments and an in-human experiment. The results illustrated that the proposed RVIR has better performance compared with the previous prototype, and preliminarily demonstrated that the proposed RVIR has good safety and reliability and can be used in clinical surgeries.

Training residents and fellows in the procedure of diagnostic cervicocerebral angiography: Techniques to avoid complications.

We examine the problems arising when training residents/fellows (RFs) initiate the learning of diagnostic cervicocerebral angiography (DCCA) and describe the steps on how to facilitate the learning process while avoiding complications. The risk of permanent neurological deficit as a result of DCCA ranges from 0.3-0.5%. Factors that correlated with complications include the following: the history of cerebral infarction, infusion of a large amount of contrast medium, a prolonged fluoroscopic time (>80 min) and the efficiency of training received. These findings suggest that the neurological morbidity depends largely upon the technique of catheterization of the patient. In order to reduce the complications arising from the lack of training, a personalised mentorship with a careful supervision of trainees is necessary. To ensure a good patient outcome, a decreased procedural time, awareness of complications at every step of the procedure and their avoidance, as well as the provision of good quality images is necessary. A mentorship program with a close supervision of the RFs is also one of the prerequisites for obtaining a good result.

Parent artery sacrifice for ruptured aneurysms in acute and chronic phases: A systematic review.

BACKGROUND: Experience with respect to parent vessel sacrifice (PVS) for unclippable/uncoilable ruptured aneurysms is limited. OBJECTIVE: The aim of the present systematic review was to evaluate the risk of PVS for unclippable/uncoilable ruptured aneurysms. MATERIALS AND METHODS: The PUBMED and SCIENCEDIRECT databases were searched using "parent vessel occlusion OR parent artery occlusion" AND "acute subarachnoid hemorrhage" till December 27, 2015, and 1 journal was searched from November 1995 to April 2016 for relevant results. RESULTS: Out of a total of 19 eligible studies, 104 patients with 104 ruptured aneurysms were treated by PVS with or without bypass surgery. Unfavorable outcome [modified Rankin Score (mRS) 4-6] was reported in 14 (13.4%) acute phase patients, with a 9.6% mortality rate. Thirty (28.8%) patients developed ischemic complications and 3 (2.9%) developed bleeding complications. The complication rate was higher for PVS in the acute phase (38.0% vs. 12.0%; P= 0.015). The unfavorable clinical outcome was found to be significant in acute phase versus chronic phase (17.7% vs. 0%; P= 0.024). The risk of morbidity associated with distal vessel [posterior cerebral artery (PCA) + superior cerebellar artery (SCA) + posterior inferior cerebellar artery (PICA)] sacrifice was not lower than that associated with major vessel [internal carotid artery (ICA) + basilar artery (BA) + vertebral artery (VA)] sacrifice (P = 0.961). CONCLUSION: Complication and unfavorable outcome rates associated with PVS for acutely ruptured aneurysms are high. The risk of distal vessel sacrifice was not lower than major vessel sacrifice in the acute phase.

MiR-29b Downregulation Induces Phenotypic Modulation of Vascular Smooth Muscle Cells: Implication for Intracranial Aneurysm Formation and Progression to Rupture.

BACKGROUND/AIMS: Our previous microarray results identified numerous microRNAs (miRNAs), including miR-29b, that were differentially expressed in the serum of intracranial aneurysm (IA) patients. The current study aimed to investigate whether miR-29b downregulation in IA could promote the phenotypic modulation of vascular smooth muscle cells (VSMCs) involved in the pathogenesis of aneurysm by activating ATG14-mediated autophagy. METHODS: First, the levels of miR-29b and autophagy related genes (ATGs) between IA patients and normal subjects were compared. Next, we modified the level of miR-29b via lentivirus particles in the VSMCs and examined the effects of miR-29b on proliferation, migration, and phenotypic modulation of VSMCs from a contractile phenotype to a synthetic phenotype, as well as the levels of autophagy. Finally, the binding of miR-29b to the 3'UTR of ATG14 mRNA and its effects on ATG14 expression were analysed by a luciferase reporter assay and Western blot, respectively. RESULTS: The level of miR-29b was decreased, and autophagy markers were increased in the IA patients compared to that of the normal subjects. Knockdown of miR-29b significantly promoted VSMCs proliferation and migration and, more importantly, induced the phenotypic modulation associated with autophagy activation, whereas miR-29b overexpression showed the opposite effects. The luciferase reporter assay demonstrated that ATG14 was a functional target gene of miR-29b. Notably, knockdown of ATG14 by siRNA apparently abrogated miR-29b inhibition-mediated phenotypic modulation. CONCLUSION: Downregulation of miR-29b induced VSMCs phenotypic modulation by directly activating ATG14-mediated autophagy, which is associated with the formation, growth and rupture of IAs.