ABSTRACT
BACKGROUND: Hemodynamic impairment of blood pressure may play a crucial role in determining the mechanisms of stroke in symptomatic intracranial atherosclerotic stenosis). We aimed to elucidate this issue and assess the impacts of modifications to blood pressure on hemodynamic impairment. METHODS: From the Third China National Stroke Registry III, computed fluid dynamics modeling was performed using the Newton-Krylov-Schwarz method in 339 patients with symptomatic intracranial atherosclerotic stenosis during 2015 to 2018. The major exposures were translesional systolic blood pressure (SBP) drop and poststenotic mean arterial pressure (MAP), and the major study outcomes were cortex-involved infarcts and borderzone-involved infarcts, respectively. Multivariate logistic regression models and the bootstrap resampling method were utilized, adjusting for demographics and medical histories. RESULTS: In all, 184 (54.3%) cortex-involved infarcts and 70 (20.6%) borderzone-involved infarcts were identified. In multivariate logistic model, the upper quartile of SBP drop correlated with increased cortex-involved infarcts (odds ratio, 1.92 [95% CI, 1.03-3.57]; bootstrap analysis odds ratio, 2.07 [95% CI, 1.09-3.93]), and the lower quartile of poststenotic MAP may correlate with increased borderzone-involved infarcts (odds ratio, 2.07 [95% CI, 0.95-4.51]; bootstrap analysis odds ratio, 2.38 [95% CI, 1.04-5.45]). Restricted cubic spline analysis revealed a consistent upward trajectory of the relationship between translesional SBP drop and cortex-involved infarcts, while a downward trajectory between poststenotic MAP and borderzone-involved infarcts. SBP drop correlated with poststenotic MAP negatively (rs=-0.765; P<0.001). In generating hemodynamic impairment, simulating blood pressure modifications suggested that ensuring adequate blood pressure to maintain sufficient poststenotic MAP appears preferable to the reverse approach, due to the prolonged plateau period in the association between the translesional SBP drop and cortex-involved infarcts and the relatively short plateau period characterizing the correlation between poststenotic MAP and borderzone-involved infarcts. CONCLUSIONS: This research elucidates the role of hemodynamic impairment of blood pressure in symptomatic intracranial atherosclerotic stenosis-related stroke mechanisms, underscoring the necessity to conduct hemodynamic assessments when managing blood pressure in symptomatic intracranial atherosclerotic stenosis.
Subject(s)
Blood Pressure , Hemodynamics , Intracranial Arteriosclerosis , Stroke , Humans , Male , Intracranial Arteriosclerosis/physiopathology , Intracranial Arteriosclerosis/complications , Female , Middle Aged , Aged , Blood Pressure/physiology , Hemodynamics/physiology , Stroke/physiopathology , Stroke/epidemiology , Registries , Constriction, Pathologic/physiopathology , China/epidemiologyABSTRACT
BACKGROUND AND OBJECTIVES: Idiopathic intracranial hypertension (IIH) is a neurologic disorder characterized by symptoms of elevated intracranial pressure in the absence of a clear cause. There is a developing theory that IIH may, in part, be related to abnormal cerebral glymphatic clearance. In addition, transverse sinus stenosis (TSS) is a common finding in IIH of unclear pathophysiologic significance. Similarly, whether or not TSS is associated with glymphatic outflow in IIH is unknown. The aim of this investigation was to explore the possible association between glymphatic outflow and extent of TSS in patients with IIH. METHODS: The study cohort consisted of patients with IIH and healthy controls who were retrospectively identified from our tertiary care institution located in upstate New York from 2016 to 2023. Patients with IIH were included if they had brain MRIs completed with sufficient sequences for analysis. Brain MRIs were computationally analyzed using diffusion tensor imaging analysis along the perivascular space technique to quantify the glymphatic function in patients with IIH. Glymphatic clearance, the primary outcome, was then correlated with the degree of TSS on MR venography using 2 different scoring systems, the 'Farb score' and 'Carvalho score.' RESULTS: Overall, 81 patients with IIH (70 [86%] female, mean age 29.8 years [SD: 8.2 years], mean BMI 41 [SD: 8.4]) and 10 normal controls were identified with sufficient imaging. Based on the Carvalho TSS score, IIH patients without TSS had significantly lower glymphatic clearance than healthy controls (mean ALPS index: 1.196 [SD: 0.05] vs 1.238 [SD: 0.04], respectively; p = 0.018). Furthermore, IIH patients with TSS had significantly lower glymphatic outflow than healthy controls (1.129 [SD: 0.07] vs 1.238 [SD: 0.04], respectively; p < 0.0001) and IIH patients without TSS (1.129 [SD: 0.07] vs 1.196 [SD: 0.05], respectively; p < 0.0001). In addition, there was a significant association between increasing extent of TSS and declining glymphatic clearance (p < 0.0001, R = 0.62). Finally, IIH patients with severe TSS had significantly lower glymphatic flow than IIH patients with mild stenosis (1.121 [SD: 0.07] vs 1.178 [SD: 0.05], respectively; p < 0.0001). These findings were similarly recapitulated using the Farb TSS scoring system. DISCUSSION: These preliminary findings suggest that the extent of TSS is associated with the degree of glymphatic clearance in IIH, providing novel insights into IIH pathophysiology. Further research is required to clarify the possible causal relationship between TSS and impaired glymphatic clearance in IIH.
Subject(s)
Glymphatic System , Pseudotumor Cerebri , Transverse Sinuses , Humans , Female , Male , Glymphatic System/diagnostic imaging , Glymphatic System/physiopathology , Adult , Pseudotumor Cerebri/physiopathology , Pseudotumor Cerebri/diagnostic imaging , Retrospective Studies , Constriction, Pathologic/diagnostic imaging , Constriction, Pathologic/physiopathology , Transverse Sinuses/diagnostic imaging , Young Adult , Middle Aged , Magnetic Resonance Imaging , Diffusion Tensor ImagingABSTRACT
Fluid structure interaction (FSI) gained attention of researchers and scientist due to its applications in science fields like biomedical engineering, mechanical engineering etc. One of the major application in FSI is to study elastic wall behavior of stenotic arteries. In this paper we discussed an incompressible Non-Newtonian blood flow analysis in an elastic bifurcated artery. A magnetic field is applied along [Formula: see text] direction. For coupling of the problem an Arbitrary Lagrangian-Eulerian formulation is used by two-way fluid structure interaction. To discretize the problem, we employed [Formula: see text] finite element technique to approximate the velocity, displacement and pressure and then linearized system of equations is solved using Newton iteration method. Analysis is carried out for power law index, Reynolds number and Hartmann number. Hemodynamic effects on elastic walls, stenotic artery and bifurcated region are evaluated by using velocity profile, pressure and loads on the walls. Study shows there is significant increase in wall shear stresses with an increase in Power law index and Hartmann number. While as expected increase in Reynolds number decreases the wall shear stresses. Also load on the upper wall is calculated against Hartmann number for different values of power law index. Results show load increases as the Hartmann number and power law index increases. From hemodynamic point of view, the load on the walls is minimum for shear thinning case but when power law index increased i.e. for shear thickening case load on the walls increased.
Subject(s)
Arteries/physiology , Blood Circulation , Constriction, Pathologic/physiopathology , Magnetic Fields , Models, Cardiovascular , Animals , Elasticity , Finite Element Analysis , Hemodynamics , Humans , HydrodynamicsABSTRACT
Quantification of pressure drop across stenotic arteries is a major element in the functional assessment of occlusive arterial disease. Accurate estimation of the pressure drop with a numerical model allows the calculation of Fractional Flow Reserve (FFR), which is a haemodynamic index employed for guiding coronary revascularisation. Its non-invasive evaluation would contribute to safer and cost-effective diseases management. In this work, we propose a new formulation of a reduced-order model of trans-stenotic pressure drop, based on a consistent theoretical analysis of the Navier-Stokes equation. The new formulation features a novel term that characterises the contribution of turbulence effect to pressure loss. Results from three-dimensional computational fluid dynamics (CFD) showed that the proposed model produces predictions that are significantly more accurate than the existing reduced-order models, for large and small symmetric and eccentric stenoses, covering mild to severe area reductions. FFR calculations based on the proposed model produced zero classification error for three classes comprising positive (≤ 0.75), negative (≥ 0.8) and intermediate (0.75 - 0.8) classes.
Subject(s)
Constriction, Pathologic/physiopathology , Coronary Stenosis/physiopathology , Coronary Vessels/physiopathology , Models, Cardiovascular , Vascular Diseases/physiopathology , Computer Simulation , Hemodynamics , Humans , HydrodynamicsABSTRACT
BACKGROUND: In adolescent idiopathic scoliosis (AIS), lung function impairment is not necessarily related to the coronal spinal deformity. Recently, right-sided bronchial narrowing has been reported in thoracic AIS. The aim of this study was to describe the relation of chest and spinal deformity parameters, bronchial narrowing, and lung volumes with pulmonary function in preoperative AIS. METHODS: Spinal radiographs, low-dose computed tomographic (CT) scans of the spine including the chest, and pulmonary function tests were retrospectively collected for 85 preoperative patients with thoracic AIS in 2 centers and were compared with 14 matched controls. Three-dimensional lung and airway reconstructions were acquired. Correlation analysis was performed in which radiographic spinal parameters, CT-based thoracic deformity parameters (rib-hump index [RHi], spinal penetration index, endothoracic hump ratio, hemithoracic-width ratio), lung volume asymmetry, and bronchial cross-sectional area were compared with percent-of-predicted spirometry results. RESULTS: Forty-one patients (48%) had a percent-of-predicted forced expiratory volume in 1 second (FEV1%) or percent-of-predicted forced vital capacity (FVC%) of <65%, and 17 patients (20%) had obstructive lung disease. All thoracic deformity parameters correlated significantly with FEV1% and FVC%; RHi was found to be the best correlate (rs = -0.52 for FEV1% and -0.54 for FVC%). Patients with AIS with impaired pulmonary function had hypokyphosis, a larger rib hump, increased spinal and thoracic rotation, a narrower right hemithorax, and increased intrusion of the spine into the chest. Spinal intrusion correlated with right-sided bronchial narrowing, relative right lung volume loss, and decreased FEV1% and FVC%. Multivariate regression including spinal and thoracic deformity parameters, lung volume asymmetry, and airway parameters could explain 57% of the variance in FEV1% and 54% of the variance in FVC%. CONCLUSIONS: Chest intrusion by the endothoracic hump is related to right-sided bronchial narrowing and lung function loss in preoperative AIS. The findings support the theory that ventilatory dysfunction in thoracic AIS is not only restrictive but frequently has an obstructive component, especially in patients with hypokyphosis. RHi is the most predictive chest parameter for lung function loss. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.
Subject(s)
Bronchi/physiopathology , Bronchial Diseases/diagnosis , Scoliosis/complications , Thorax/physiopathology , Adolescent , Adult , Bronchi/diagnostic imaging , Bronchial Diseases/etiology , Bronchial Diseases/physiopathology , Case-Control Studies , Child , Constriction, Pathologic/diagnosis , Constriction, Pathologic/etiology , Constriction, Pathologic/physiopathology , Female , Humans , Male , Respiratory Function Tests , Retrospective Studies , Thoracic Vertebrae , Thorax/diagnostic imaging , Tomography, X-Ray Computed , Vital Capacity , Young AdultABSTRACT
BACKGROUND: Adenosine deaminase acting on RNA 3 (ADAR3) was known as a prognosis factor in gliomas, while its function on neuropathic pain (NP) is barely investigated. Therefore, our present study concentrated on the potential role of ADAR3 in NP. METHODS: The chronic constriction injury (CCI) mouse model was established to induce NP in vivo. Behavioral experiments were carried out to analyze mechanical allodynia and thermal hyperalgesia. RT-qPCR and western blotting assays were used to detect the mRNA and protein expressions. The ADAR3-overexpressed adenovirus was injected into the CCI mice through an intrathecal catheter. ELISA was used to detect the contents of IL (interleukin)-6, IL-10, TNF (tumor necrosis factor)-α, IL-1ß and IL-18. NLR Family Pyrin Domain Containing 3 (NLRP3) was predicted to be the target gene of ADAR3 using Starbase. The interaction between ADAR3 and NLRP3 was verified via RNA pull-down, RNA immunoprecipitation and Pearson's correlation coefficient assays. Immunohistochemical staining assay visualized the expressions of NLRP3 and caspase1. RESULTS: Allodynia and hyperalgesia were exacerbated in the CCI mice, which implied a successful establishment of the NP model, while ADAR3 expression level was suppressed. After injecting ADAR3-overexpressed adenovirus into the CCI mice, allodynia, hyperalgesia and inflammation were all restrained. Moreover, NLRP3 was verified to negatively correlated with ADAR3. Additionally, the pyroptosis-related protein NLRP3, ASC, caspase1, IL-1ß, IL-18 and GSDMD expressions were all decreased by ADAR3. CONCLUSION: In conclusion, ADAR3 alleviated inflammation and pyroptosis of NP through targeting NLRP3, which suggested a therapeutical target for NP.
Subject(s)
Adenosine Deaminase/genetics , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Neuralgia/genetics , Adenosine Deaminase/metabolism , Animals , Constriction, Pathologic/physiopathology , Hyperalgesia/genetics , Inflammation/genetics , Inflammation/metabolism , Interleukin-10/metabolism , Interleukin-18/metabolism , Interleukin-1beta/metabolism , Interleukin-6/metabolism , Male , Mice , Mice, Inbred C57BL , NLR Family, Pyrin Domain-Containing 3 Protein/genetics , Neuralgia/metabolism , Pyroptosis/genetics , Pyroptosis/physiology , Tumor Necrosis Factor-alpha/metabolismABSTRACT
Background Arterial hypertension affects cardiovascular outcome in patients with peripheral artery disease (PAD). We hypothesized that angioplasty of peripheral arterial stenoses decreases aortic (aBP) and brachial blood pressure (bBP). Methods and Results In an index cohort (n=30), we simultaneously measured aBP, bBP, augmentation index (AIx), and aortic pulse wave velocity (PWV) before and after angioplasty of the iliac and femoropopliteal arteries; diagnostic angiography served as a control. In an all-comer registry cohort (n=381), we prospectively measured bBP in patients scheduled for angioplasty of the iliac, femoral, and crural arteries or diagnostic angiography. Systolic aBP decreased after iliac (Δ-25 mmHg; 95% CI, -30 to -20; P<0.0001) and femoropopliteal angioplasty (Δ-12 mmHg; 95% CI, -17 to -5; P<0.0001) as compared with diagnostic angiography. Diastolic aBP decreased after iliac (Δ-9 mmHg; 95% CI, -13 to -1; P=0.01) but not femoropopliteal angioplasty. In parallel, AIx significantly dropped, whereas PWV remained stable. In the registry cohort, systolic bBP decreased after angioplasty of the iliac (Δ-17 mmHg; 95% CI, -31 to -8; P=0.0005) and femoropopliteal arteries (Δ-10 mmHg; 95% CI, -23 to -1; P=0.04) but not the crural arteries, as compared with diagnostic angiography. Diastolic bBP decreased after iliac (Δ-10 mmHg; 95% CI, -17 to -2; P=0.01) and femoropopliteal angioplasty (Δ-9 mmHg; 95% CI, -15 to -1; P=0.04). Multivariate analysis identified baseline systolic bBP and site of lesion as determinants of systolic bBP drop after endovascular treatment. Conclusions Angioplasty of flow-limiting stenoses in patients with peripheral artery disease lowers aortic and brachial blood pressure with more pronounced effects at more proximal lesion sites and elevated baseline systolic blood pressure. These data indicate a role of endovascular treatment to acutely optimize blood pressure in patients with peripheral artery disease. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT02728479.
Subject(s)
Blood Pressure/physiology , Hypertension/physiopathology , Peripheral Arterial Disease/physiopathology , Vascular Stiffness/physiology , Aged , Aged, 80 and over , Angioplasty/methods , Aorta/physiopathology , Brachial Artery/physiopathology , Constriction, Pathologic/diagnosis , Constriction, Pathologic/physiopathology , Female , Humans , Hypertension/diagnosis , Male , Middle Aged , Multivariate Analysis , Peripheral Arterial Disease/diagnosis , Prospective Studies , Pulse Wave AnalysisABSTRACT
BACKGROUND: The implantation of cardiac implantable electronic devices (CIED) has increased in the last decades with improvement in the quality of life of patients with cardiac rhythm disorders. The presence of bilateral subclavian, innominate or superior vena cava obstruction is a major limitation to device revision and/or upgrade. METHODS AND MATERIAL: This is retrospective study of patients who underwent laser-assisted lead extraction (LLE) (GlideLight laser sheath, Spectranetics Corporation, Colorado Springs, USA) with lead revision or upgrade using the laser sheath as a guide rail. Patients with known occlusion, severe stenosis or functional obstruction of the venous access vessels with indwelling leads were included in this study. RESULTS: 106 patients underwent percutaneous LLE with lead revision and/or upgrade. Preoperative known complete occlusion or severe stenosis of access veins was present in 23 patients (21.5%). More patients with implantable cardioverter-defibrillator (ICD) underwent LLE (64.1%) than patients with CRT-Ds (24.5%) and pacemaker patients (11.3%). In total 172 leads were extracted: 79 (45.9%) single-coil defibrillator leads, 35 (20.3%) dual-coil defibrillator leads, 31 (18.0%) right atrial leads, 24 (13.9%) right ventricular leads and three (1.7%) malfunctional coronary sinus left ventricular pacing leads. The mean age of leads was 99.2±65.6 months. The implantation of new leads after crossing the venous stenosis/obstruction was successful in 98 (92.4%) cases. Postoperative complications were pocket hematoma in two cases and wound infection in one case. No peri-operative and no immediate postoperative death was recorded. One intraoperative superior vena cava tear was treated by immediate thoracotomy and surgical repair. CONCLUSION: In a single-center study on LLE in the presence of supra-cardiac occlusion of the central veins for CIED lead upgrade and revision we could demonstrate a low procedural complication rate with no procedural deaths. Most of the leads could be completely extracted to revise or upgrade the system. Our study showed a low complication rate, with acceptable mortality rates.
Subject(s)
Constriction, Pathologic/surgery , Defibrillators, Implantable , Pacemaker, Artificial , Vascular Diseases/surgery , Aged , Catheters, Indwelling , Constriction, Pathologic/physiopathology , Device Removal/adverse effects , Device Removal/methods , Equipment Failure , Female , Humans , Lasers , Male , Middle Aged , Postoperative Complications/epidemiology , Postoperative Complications/physiopathology , Postoperative Complications/surgery , Retrospective Studies , Vascular Diseases/physiopathology , Vena Cava, Superior/physiopathology , Vena Cava, Superior/surgerySubject(s)
Keratoderma, Palmoplantar/diagnosis , Keratoderma, Palmoplantar/drug therapy , Adolescent , Ainhum/diagnosis , Ainhum/physiopathology , Constriction, Pathologic/diagnosis , Constriction, Pathologic/physiopathology , Excitatory Amino Acid Antagonists/pharmacology , Excitatory Amino Acid Antagonists/therapeutic use , Female , Gabapentin/pharmacology , Gabapentin/therapeutic use , HumansABSTRACT
In-stent restenosis (ISR) represents a major drawback of stented superficial femoral arteries (SFAs). Motivated by the high incidence and limited knowledge of ISR onset and development in human SFAs, this study aims to (i) analyze the lumen remodeling trajectory over 1-year follow-up period in human stented SFAs and (ii) investigate the impact of altered hemodynamics on ISR initiation and progression. Ten SFA lesions were reconstructed at four follow-ups from computed tomography to quantify the lumen area change occurring within 1-year post-intervention. Patient-specific computational fluid dynamics simulations were performed at each follow-up to relate wall shear stress (WSS) based descriptors with lumen remodeling. The largest lumen remodeling was found in the first post-operative month, with slight regional-specific differences (larger inward remodeling in the fringe segments, p < 0.05). Focal re-narrowing frequently occurred after 6 months. Slight differences in the lumen area change emerged between long and short stents, and between segments upstream and downstream from stent overlapping portions, at specific time intervals. Abnormal patterns of multidirectional WSS were associated with lumen remodeling within 1-year post-intervention. This longitudinal study gave important insights into the dynamics of ISR and the impact of hemodynamics on ISR progression in human SFAs.
Subject(s)
Constriction, Pathologic/physiopathology , Femoral Artery/pathology , Femoral Artery/physiopathology , Stents/adverse effects , Aged , Hemodynamics , Humans , Hydrodynamics , Male , Middle Aged , Patient-Specific ModelingABSTRACT
OBJECTIVES/HYPOTHESIS: Glottic stenosis is a discrete cause of airway compromise. We aimed to determine the surgical outcomes of transverse cordotomy with anteromedial arytenoidectomy (TCAMA), performed in the setting of isolated glottic stenosis resulting from two discrete etiologies: bilateral vocal fold paralysis (BVFP) and posterior glottic stenosis (PGS). STUDY DESIGN: Retrospective, analytic cohort study. METHODS: Twenty-six patients with isolated glottic stenosis were treated with TCAMA between 2006 and 2019. A retrospective analysis determined decannulation rates and intervals, voice outcomes, swallowing outcomes, and reoperation rates postoperatively. Outcomes between the two etiologic cohorts were compared. RESULTS: Of the 26 patients, 16/26 patients were diagnosed with PGS and 10/26 with BVFP. Eighteen patients required tracheotomies during their clinical course (11/16 PGS, and 7/10 BVFP), and 100% were ultimately decannulated. The PGS cohort required two-sided interventions more frequently than the BVFP cohort (45.5% vs. 0%, P = .066). Trach-dependent PGS patients required a longer time to achieve decannulation than BVFP patients by a factor of 2.38, although the difference was not statistically significant (102.3 days vs. 42.9 days, respectively, P = .113). Patients demonstrated a significant change in maximum phonation time but no statistically significant differences with preoperative versus postoperative voice outcomes like voice-related quality of life. All patients ultimately returned to their baseline swallow function postoperatively. CONCLUSION: TCAMA is an effective treatment for surgical rehabilitation of glottic stenosis caused by both BVFP and PGS. Patient-reported outcomes of postoperative vocal function remain consistent following surgical intervention. Additional, prospective studies with greater power are warranted to validate the contrasting outcomes observed when applying this discrete surgical technique across two distinct diagnostic cohorts in this retrospective study. LEVEL OF EVIDENCE: 4. Laryngoscope, 131:2305-2311, 2021.
Subject(s)
Arytenoid Cartilage/surgery , Constriction, Pathologic/surgery , Glottis/surgery , Laryngectomy/methods , Vocal Cord Paralysis/surgery , Adult , Aged , Arytenoid Cartilage/diagnostic imaging , Combined Modality Therapy/methods , Constriction, Pathologic/diagnosis , Constriction, Pathologic/etiology , Constriction, Pathologic/physiopathology , Deglutition/physiology , Female , Glottis/diagnostic imaging , Humans , Laryngoscopy/methods , Male , Middle Aged , Patient Reported Outcome Measures , Quality of Life , Reoperation/statistics & numerical data , Retrospective Studies , Stroboscopy/methods , Treatment Outcome , Vocal Cord Paralysis/diagnosis , Vocal Cord Paralysis/physiopathology , Voice Quality/physiologyABSTRACT
The use of neonatal hearing screening has enabled the identification of congenital unilateral sensorineural hearing loss (USNHL) immediately after birth, and today there are several intervention options available to minimize potential adverse effects of this disease, including cochlear implantation. This study aims to analyze the characteristics of the inner ear of a homogeneous group of congenital non-syndromic USNHL to highlight the features of the inner ear, which can help in clinical, surgical, and rehabilitative decision-making. A retrospective chart review was carried out at a tertiary referral center. Systematic diagnostic work-up and rigorous inclusion-exclusion criteria were applied to 126 children with unilateral hearing impairment, leading to a selection of 39 strictly congenital and non-syndromic USNHL cases, undergoing computed tomography (CT) and magnetic resonance (MR) imaging studies. The frequency and type of malformations of the inner ear in USNHL and unaffected contralateral ears were assessed, with an in-depth analysis of the deficiency of the cochlear nerve (CND), the internal auditory canal (IAC) and the cochlear aperture (CA). Inner ear anomalies were found in 18 out of 39 (46%) of the USNHL patients. In 1 subject, the anomalies were bilateral, and the CND resulted in the predominant identified defect (78% of our abnormal case series), frequently associated with CA stenosis. Only 3 out of 14 children with CND presented stenosis of the IAC. CND and CA stenosis (and to a much lesser extent IAC stenosis) are a frequent association within congenital and non-syndromic USNHL that could represent a distinct pathological entity affecting otherwise healthy infants. In the context of a diagnostic work-up, the evaluation with CT and MRI measurements should take place in a shared decision-making setting with thorough counseling. Both imaging techniques have proven useful in differentiating the cases that will most likely benefit from the cochlear implant, from those with potentially poor implant performance.
Subject(s)
Cochlea , Cochlear Implantation , Cochlear Implants , Cochlear Nerve , Hearing Loss, Sensorineural , Magnetic Resonance Imaging , Tomography, X-Ray Computed , Child , Child, Preschool , Cochlea/diagnostic imaging , Cochlea/physiopathology , Cochlea/surgery , Cochlear Nerve/diagnostic imaging , Cochlear Nerve/physiopathology , Constriction, Pathologic/diagnostic imaging , Constriction, Pathologic/physiopathology , Constriction, Pathologic/surgery , Hearing Loss, Sensorineural/diagnostic imaging , Hearing Loss, Sensorineural/physiopathology , Hearing Loss, Sensorineural/surgery , Humans , Infant , Male , Retrospective StudiesABSTRACT
MRI can assess plaque composition and has demonstrated an association between some atherosclerotic risk factors (RF) and markers of plaque vulnerability in naive patients. We aimed at investigating this association in medically treated asymptomatic patients. This is a cross-sectional interim analysis (August 2013-September 2016) of a single center prospective study on carotid plaque vulnerability (MAGNETIC study). We recruited patients with asymptomatic carotid atherosclerosis (US stenosis > 30%, ECST criteria), receiving medical treatments at a tertiary cardiac rehabilitation. Atherosclerotic burden and plaque composition were quantified with 3.0 T MRI. The association between baseline characteristics and extent of lipid-rich necrotic core (LRNC), fibrous cap (CAP) and intraplaque hemorrhage (IPH) was studied with multiple regression analysis. We enrolled 260 patients (198 male, 76%) with median age of 71-y (interquartile range: 65-76). Patients were on antiplatelet therapy, ACE-inhibitors/angiotensin receptor blockers and statins (196-229, 75-88%). Median LDL-cholesterol was 78 mg/dl (59-106), blood pressure 130/70 mmHg (111-140/65-80), glycosylated hemoglobin 46 mmol/mol (39-51) and BMI 25 kg/m2 (23-28); moreover, 125 out of 187 (67%) patients were ex-smokers. Multivariate analysis of a data-set of 487 (94%) carotid arteries showed that a history of hypercholesterolemia, diabetes, hypertension or smoking did not correlate with LRNC, CAP or IPH. Conversely, maximum stenosis was the strongest independent predictor of LRNC, CAP and IPH (p < 0.001). MRI assessment of plaque composition in patients on treatment for asymptomatic carotid atherosclerosis shows no correlation between plaque vulnerability and the most well-controlled modifiable RF. Conversely, maximum stenosis exhibits a strong correlation with vulnerable features despite treatment.
Subject(s)
Carotid Arteries/physiopathology , Carotid Artery Diseases/physiopathology , Constriction, Pathologic/physiopathology , Aged , Aged, 80 and over , Angiotensin Receptor Antagonists/therapeutic use , Blood Pressure/physiology , Cross-Sectional Studies , Female , Glycated Hemoglobin/metabolism , Humans , Male , Middle Aged , Multivariate Analysis , Prospective Studies , Risk FactorsABSTRACT
BACKGROUND: Percutaneous transluminal angioplasty (PTA) has generally replaced surgical procedures to treat arteriovenous fistula (AVF) dysfunction, but the predictors of post-intervention patency are highly variable. This study aimed to determine predictors of primary patency following PTA of dysfunctional AVF. MATERIALS AND METHODS: Retrospective analysis of first-time PTA of 307 AVF in 307 patients (171 males, mean age 64.3 ± 12.4 years). Demographic, clinical, anatomical and medication variables were reviewed and subjected to univariate and multivariate Cox regression analysis. RESULTS: The post-intervention primary patency rates at 6, 12, 24, and 36 months were 76.3%, 58.3%, 43.2%, and 38.2%, respectively. The higher aortic arch calcification (AAC) grade patients were older, had higher incidence of comorbidities and cardiomegaly, and younger AVF age, but their dialysis vintage term was shorter and diastolic blood pressure was lower, and the maximum diameter of balloon angioplasty was mostly ≤ 6 mm, and had lower phosphorus level and less calcium-containing phosphate binder use. In multivariate Cox proportional hazard analysis, the presence of higher AAC grade [hazard ratio (95% confidence interval): (1.46 (1.02-2.09); p = 0.037)] and stenosis at upper arm [1.76 (1.16-2.67); p = 0.008] were associated with shorter post-intervention primary patency. CONCLUSION: In conclusion, higher AAC grade and anatomic factor related to the location of AVF (upper arm) were the important predictors of AVF dysfunction after PTA. These results could assist in tailoring surveillance programs and performing appropriate interventions for risky AVF.
Subject(s)
Angioplasty , Arteriovenous Shunt, Surgical/adverse effects , Renal Dialysis , Vascular Calcification/physiopathology , Vascular Patency , Aged , Angioplasty/methods , Aorta, Thoracic , Arm/blood supply , Blood Vessels/pathology , Constriction, Pathologic/physiopathology , Female , Humans , Male , Middle Aged , Retrospective Studies , Risk Factors , Severity of Illness Index , Time Factors , Vascular Calcification/complicationsABSTRACT
Pulmonary vein stenosis is a rare and poorly understood condition causing obstruction of the large pulmonary veins and of blood flow from the lungs to the left atrium. This results in elevated pulmonary venous pressure and pulmonary edema, pulmonary hypertension, potentially cardiac failure, and death. Clinical signs of the disease include failure to thrive, increasingly severe dyspnea, hemoptysis, respiratory difficulty, recurrent respiratory tract infections/pneumonia, cyanosis, and subcostal retractions. On chest radiograph, the most frequent finding is increased interstitial, ground-glass and/or reticular opacity. Transthoracic echocardiography with pulsed Doppler delineates the stenosis, magnetic resonance imaging and multislice computerized tomography are used for further evaluation. Interventional cardiac catherization, surgical techniques, and medical therapies have been used with varying success as treatment options.
Subject(s)
Constriction, Pathologic/diagnostic imaging , Pulmonary Veins/diagnostic imaging , Stenosis, Pulmonary Vein/diagnostic imaging , Angioplasty , Cardiac Catheterization , Child , Child, Preschool , Constriction, Pathologic/physiopathology , Echocardiography/methods , Hemodynamics , Hemoptysis , Humans , Infant , Magnetic Resonance Imaging/methods , Pulmonary Veins/physiopathology , Stenosis, Pulmonary Vein/physiopathology , Stenosis, Pulmonary Vein/therapy , Stents , Tomography, X-Ray Computed , Treatment OutcomeABSTRACT
BACKGROUND: Endovascular management is used to treat Takayasu arteritis (TA) involving the supra-aortic branches. However, the long-term outcome of this treatment remains unclear. Here, technical safety, outcomes, and restenosis management of supra-aortic arteries in TA patients receiving endovascular treatment were evaluated. METHODS: TA patients with symptomatic supra-aortic stenosis who underwent percutaneous angioplasty and stenting between 2008 and 2018 at our institute were enrolled in this study. Pre- and post-procedural magnetic resonance imaging (MRI) evaluations, including high-resolution vessel wall imaging (HR-VWI), were performed. Technical efficacy, peri-procedural complications, early post-procedural MRI results, and stent patency were examined. RESULTS: All six patients successfully received stent placement or percutaneous transluminal angioplasty in a total of 22 treated arteries without neurologic complications. During follow-up (mean, 56.3 ± 41.1 months), no recurrent stroke occurred, yet significant restenosis developed in 12 of 22 (54.5%) of the treated arteries. Three of the patients underwent HR-VWI before surgery. Concentric wall thickening and enhancement of the left common carotid artery was detected in one patient, indicating acute inflammation. Angioplasty with drug-eluting balloon (DEB) successfully treated a case of refractory restenosis. Among 10 early post-procedure MRI performed, only two asymptomatic new lesions were detected with diffusion-weighted imaging. CONCLUSION: Endovascular treatment of supra-aortic arteries of TA patients was safe and effective, yet was associated with a high restenosis rate. Thus, close follow-up is needed. HR-VWI is helpful for pre-procedural selection of patients for percutaneous angioplasty and stenting and drug-eluting balloon angioplasty appears to be a promising treatment for refractory in-stent restenosis.
Subject(s)
Constriction, Pathologic/physiopathology , Endovascular Procedures , Takayasu Arteritis/therapy , Adolescent , Adult , Angioplasty, Balloon , Carotid Stenosis , Female , Humans , Middle Aged , Stents , Treatment Outcome , Young AdultABSTRACT
BACKGROUND: Pulsatile tinnitus (PT) is a debilitating condition that can be caused by a vascular abnormality, such as an arterial or venous lesion. Although treatment of PT-related venous lesions has been shown to successfully cure patients of the associated 'tormenting' rhythmical sound, much controversy still exists regarding their role in the etiology of PT. METHODS: A patient presented with a history of worsening, unilateral PT. A partial venous sinus obstruction related to the large arachnoid granulation was detected on the right side, and subsequently stented at the right transverse sinus. High-fidelity computational fluid dynamics (CFD) was performed on a 3D model digitally segmented from the pre-stent venogram, with assumed pulsatile flow rates. A post-stent CFD model was also constructed from this. Data-driven sonification was performed on the CFD velocity data, blinded to the patient's self-reported sounds. RESULTS: The patient reported that the PT was completely resolved after stenting, and has had no recurrence of the symptoms after more than 2 years. CFD simulation revealed highly disturbed, turbulent-like flow at the sigmoid sinus close to auditory structures, producing a sonified audio signal that reproduced the subjective sonance of the patient's PT. No turbulence or sounds were evident at the stenosis, or anywhere in the post-stent model. CONCLUSIONS: For the first time, turbulence generated distal to a venous stenosis is shown to be a cause of PT. High-fidelity CFD may be useful for identifying patients with such 'torrents' of flow, to help guide treatment decision-making.
Subject(s)
Computer Simulation , Hemodynamics , Imaging, Three-Dimensional , Stents , Tinnitus , Transverse Sinuses , Vascular Surgical Procedures , Cerebrovascular Disorders/diagnosis , Cerebrovascular Disorders/etiology , Cerebrovascular Disorders/surgery , Constriction, Pathologic/complications , Constriction, Pathologic/physiopathology , Constriction, Pathologic/surgery , Humans , Magnetic Resonance Angiography/methods , Male , Middle Aged , Phlebography/methods , Tinnitus/etiology , Tinnitus/physiopathology , Tinnitus/surgery , Transverse Sinuses/pathology , Transverse Sinuses/surgery , Treatment Outcome , Vascular Surgical Procedures/instrumentation , Vascular Surgical Procedures/methodsABSTRACT
Cardiovascular diseases are among the leading causes of death in the world. The coronary blockage is one of most common types of these diseases that in the majority of cases has been treated by bypass surgery. In the bypass surgery, a graft is implemented to alter the blocked coronary and allow the blood supply process. The hemodynamic characteristics of the bypass strongly depend on the geometry and mechanical properties of the graft. In the present study, the fluid-structure interaction (FSI) analysis is conducted to investigate the bypass performance for a thoracic artery as well as a saphenous vein graft. Blood flow introduces a pressure on the walls of the graft which behaves as a hyperelastic material. A complete coronary bypass with stenosis degrees of 70% and 100% is modeled. To consider the nonlinear stress-strain behavior of the grafts, a five parameter Mooney-Rivlin hyperplastic model is implemented for the structural analysis and blood is assumed to behave as a Newtonian fluid. The simulations are performed for a structured grid to solve the governing equations using finite element method (FEM). The results show that wall shear stress (WSS) for saphenous vein is larger than that of thoracic artery while the total deformation of the thoracic artery is larger compared to the saphenous vein. Also, for the venous grafts or lower stenosis degree, the oscillatory shear index (OSI) is higher at both left and right anastomoses meaning that venous grafts as well as lower degree of stenosis are more critical in terms of restenosis.
Subject(s)
Coronary Artery Bypass/methods , Coronary Stenosis/physiopathology , Hemodynamics , Saphenous Vein/transplantation , Vascular Grafting/methods , Algorithms , Anastomosis, Surgical , Constriction, Pathologic/physiopathology , Coronary Restenosis , Coronary Vessels/physiopathology , Finite Element Analysis , Fourier Analysis , Humans , Hydrodynamics , Imaging, Three-Dimensional , Models, Theoretical , Oscillometry , Saphenous Vein/physiopathology , Shear Strength , Stress, MechanicalABSTRACT
BACKGROUND: Veins are thin-walled tubes. Their lumen is roughly circular with an aspect ratio close to 1:1 under physiologic pressures. When they collapse owing to decreased internal pressure or external compression, the aspect ratio changes. The vertical diameter is usually diminished more than the transverse, with a considerable decrease in the lumen area. The recent emergence of stent correction of many venous compression syndromes, particularly iliac vein stenosis, has brought attention to the importance of the aspect ratio, quite apart from an overall decrease in caliber. The iliac vein pressure is influenced not only by stenosis, but also intra-abdominal pressure, right atrial pressure, and collaterals. We investigated the impact of aspect ratio in an experimental model incorporating these factors. METHODS: Inflow was provided from a header tank at 25 mm Hg pressure into a Penrose tubing enclosed in a polyethylene cylinder pressurized (Starling pressure) to simulate intra-abdominal pressures of 5 and 10 mm Hg. The Penrose drained into an outflow tank with a pressure of 7 mm Hg, simulating right atrial pressure. Stenosis was simulated with a series of three-dimensional, printed plastic nozzles with caliber areas of 50, 100, and 200 mm2 and varying in aspect ratios of 1:1 to 1:4. The flow and pressure in this system was monitored with the use of overflow collaterals in some experiments. RESULTS: Free flow from the header tank through the Penrose (zero Starling pressure) with a 200 mm2 circle nozzle into the outflow tank with zero pressure resulted in flow pressure of approximately 1.5 mm Hg. Using nozzles of a smaller caliber or an increased aspect ratio resulted in an increase of flow pressures of up to approximately 3.7 mm Hg. Flow into an outflow tank of 7 mm Hg simulating right atrial pressure further increased flow pressures by approximately 7 mm Hg. The addition of Starling pressures of 5 and 10 mm Hg simulating abdominal pressure increased flow pressure even further to the 10 to 17 mm Hg range. When the Starling pressure was dominant, the additional contribution of nozzle caliber stenosis or aspect ratio reduction to the overall flow pressure ranged from 2 to 6 mm Hg. Collateral overflow varied inversely with collateral resistance. Some experiments yielded an anomalous flow/pressure phenomena known to occur in collapsible tube flows. CONCLUSIONS: A decrease in the caliber or the aspect ratio of iliac vein stenosis was among several other factors that generate peripheral venous hypertension in an experimental model. Increased intra-abdominal pressure is a major influence that amplifies the pressure effects of aspect ratio or caliber reduction.
Subject(s)
Iliac Vein/pathology , Iliac Vein/physiopathology , Venous Pressure , Abdomen/physiopathology , Collateral Circulation , Constriction, Pathologic/physiopathology , Heart Atria/physiopathology , Humans , Models, Biological , Pressure , Regional Blood FlowABSTRACT
OBJECTIVE: Crocin as an important constituent of saffron has antineuropathic pain properties; however, the exact mechanism of this effect is not known. The aim of this study was whether the hypoalgesic effect of crocin can be exerted through muscarinic receptors. MATERIALS AND METHODS: In the present project, 36 male Wistar rats (200 ± 20 g) were used. Animals randomly divided into six groups (sham, neuropathy, neuropathy + crocin, neuropathy + atropine 0.5 mg/kg, neuropathy + atropine 1 mg/kg, and neuropathy + atropine 1 mg/kg + crocin). Neuropathy was induced by the chronic constriction injury (CCI) method on the sciatic nerve. Crocin and atropine was administered intraperitoneally during 14 days following the 14th day after surgery. Pain response was detected every three days, two hours after each injection and 3 days following last injection. Mechanical allodynia and thermal hyperalgesia were detected using the Von Frey filaments and plantar test device, respectively. RESULTS: CCI significantly reduced the paw withdrawal response to mechanical and thermal stimulus (P < 0.01 and P < 0.05, respectively). Crocin therapy significantly reduced mechanical allodynia and thermal hyperalgesia induced by CCI (P < 0.05). Atropine pretreatment significantly blocked the hypoalgesic effect of crocin (P < 0.05 in mechanical allodynia and P < 0.01 in thermal hyperalgesia). Fourteen days administration of atropine alone at a dose of 0.5 mg/kg but not 1 mg/kg significantly reduced CCI-induced mechanical allodynia at day 30 after surgery. CONCLUSION: Crocin significantly decreased CCI-induced neuropathic pain. The hypoalgesic effect of crocin was blocked by atropine pretreatment, which indicates an important role for muscarinic receptors in the effect of crocin.