Trends in venous diameter and brachial artery volume flow of AVF in 12 weeks postoperatively.

OBJECTIVE: To explore the trends of venous diameter and brachial artery volume flow (VF) in 12 weeks after arteriovenous fistula (AVF) and the influence of preoperative arterial diameter on this trend. Our goal was to clarify the maturation process within 12 weeks after AVF surgery. METHODS: Clinical data of 257 patients with end-stage renal disease who had their first radial-cephalic AVF established at our institution from February 1, 2023 to February 1, 2024 were included. The patients were divided into group A (radial artery diameter <1.5 mm), group B (radial artery diameter 1.5-2.0 mm), and group C (radial artery diameter >2.0 mm) according to the preoperative radial artery diameter. After AVF surgery, the artery and vein diameter, brachial artery VF were recorded at 1 day, 2 weeks, 4 weeks, 6 weeks, 8 weeks, 10 weeks and 12 weeks. RESULTS: 1. The venous diameter and brachial artery VF of AVF showed an upward trend, and increased significantly in 1 day-6 weeks postoperatively (P < 0.05),especially between 1 day and 2 weeks, while no significant difference in the increases at 6-12 weeks. 2. Groups B and C were in line with the above trend, whereas the patients in group A showed best growth in 2-4 weeks postoperatively. 3. The natural maturation rates of AVF in groups B and C were significantly better than that of group A at all postoperative time (P＜0.05). CONCLUSION: The AVF was in a developmentally dominant stage at 6 weeks postoperatively, with 1 day-2 weeks being particularly prominent. The postoperative natural maturation rate of AVF with arteries diameter of<1.5 mm was low, the direct use of such arteries to establish AVF need careful consideration.

Feasibility and radial artery occlusion rate of sheathless distal transradial access using balloon guide catheters.

Distal transradial access (dTRA), performed through an anatomical snuffbox, minimizes post-procedural burdens of endovascular treatments. However, despite the benefits of balloon-guide catheters (BGCs), their use in dTRA is limited by their small radial artery diameter. Herein, we evaluated the feasibility and radial artery occlusion (RAO) rate of 8Fr BGCs used in sheathless dTRA. This retrospective study reviewed patients treated with sheathless dTRA using an 8Fr Optimo at a single center between July 2023 and May 2024. dTRA procedures were performed under general anesthesia in patients not requiring urgent treatment. The RAO was assessed using ultrasonography 24 h after the procedure. The demographic and procedural characteristics were compared between the radial artery patency and occlusion groups. Of 170 patients, 50 underwent dTRA, and 43 (86%) completed the procedure. RAO occurred in 12/43 (28%) patients with dTRA. Univariate and receiver operating characteristic curve analyses demonstrated that the median radial artery diameter was significantly smaller in the RAO group (P < 0.001), with an optimal cut-off value of 2.4 mm to predict RAO. Complications included minor cerebral ischemia in two patients, but no severe ischemia was observed. Sheathless dTRA using an 8Fr Optimo BGC is feasible, but the risk of RAO should be noted, particularly in patients with small radial artery diameters. This study suggests a radial artery diameter cutoff value of 2.4 mm to predict RAO, aiding access decisions for large-bore BGC. Further multicenter prospective studies are warranted to confirm these findings and assess long-term outcomes.

Brain artery diameters and risk of dementia and stroke.

INTRODUCTION: We tested the association of brain artery diameters with dementia and stroke risk in three distinct population-based studies using conventional T2-weighted brain magnetic resonance imaging (MRI) images. METHODS: We included 8420 adults > 40 years old from three longitudinal population-based studies with brain MRI scans. We estimated and meta-analyzed the hazard ratios (HRs) of the brain and carotids and basilar diameters associated with dementia and stroke. RESULT: Overall and carotid artery diameters > 95th percentile increased the risk for dementia by 1.74 (95% confidence interval [CI], 1.13-2.68) and 1.48 (95% CI, 1.12-1.96) fold, respectively. For stroke, meta-analyses yielded HRs of 1.59 (95% CI, 1.04-2.42) for overall arteries and 2.11 (95% CI, 1.45-3.08) for basilar artery diameters > 95th percentile. DISCUSSION: Individuals with dilated brain arteries are at higher risk for dementia and stroke, across distinct populations. Our findings underline the potential value of T2-weighted brain MRI-based brain diameter assessment in estimating the risk of dementia and stroke.

Does ponticulus posticus affect vertebral artery diameter.

PURPOSE: Ponticulus Posticus, atlantooccipital ligament ossification-induced anomaly, surrounds the vertebral artery and the first cervical nerve root. It is believed to wrap around the first cervical nerve root and the vertebral artery, causing compression. We hypothesized that it would also reduce the diameter of the vertebral artery. METHODS: Between January 1, 2022, and December 31, 2022, cervical spine CT scans taken for any reason were retrospectively reviewed. The images of 1365 patients suitable for evaluation were evaluated by two expert radiologists in 3 dimensions. Among patients with PP, those who underwent cervical angiography were identified for vertebral artery diameter measurement. RESULTS: The average age of the 1365 individuals included in the study (732 males, 633 females) was 55.78 (± 18.85) with an age range of 1-96. Among this group, PP was detected in 288 individuals, resulting in a total prevalence of 21.1%. Right and left vertebral artery diameters were significantly lower in patients with complete PP compared to the absent group (p < 0,001, p < 0,001, respectively). Additionally, it was observed that width and height diameters and artery diameters were positively correlated in patients with Complete PP. CONCLUSIONS: Ponticulus posticus can cause vertebrobasilar insufficiency by reducing the diameter of the vertebral artery. Therefore, imaging and detailed evaluation of this region are important in symptomatic patients.

Screening for portopulmonary hypertension using computed tomography-based measurements of the main pulmonary artery and ascending aorta diameters in patients with portal hypertension.

AIM: This study aimed to demonstrate the feasibility of identifying candidates of portopulmonary hypertension (PoPH) from general portal hypertension patients based on chest computed tomography (CT) results. METHODS: One hundred and thirty patients with portal hypertension who had undergone interventional radiology therapies at our hospital between August 2011 and July 2021 were included, and preoperative clinical data were collected. Suspicious PoPH was defined as main pulmonary artery diameter (mPA-D) ≥ 29 mm or the ratio of mPA-D to ascending aorta diameter (mPA-D/aAo-D) ≥ 1.0, and probable PoPH as mPA-D ≥ 33 mm based on the chest CT. Prevalence of suspicious and probable PoPH was evaluated, and the differences in clinical characteristics of each population were compared. RESULTS: Overall, 29 (22.3%) and 5 (3.8%) patients were categorized as suspicious and probable PoPH, respectively. Univariate analyses revealed that female sex, higher shortest diameter of inferior vena cava, presence of portosystemic shunts ≥ 5 mm, and lower blood urea nitrogen levels were significantly associated with suspicious PoPH (p < 0.05). Multivariate analyses identified all four factors as significantly independent determinants of suspicious PoPH (p < 0.05). In addition, among the population of suspicious PoPH, there were significant differences in seven parameters, including total bilirubin levels and spleen volume between patients with and without probable PoPH (p < 0.05). However, no significant independent indicators of probable PoPH were found. CONCLUSIONS: CT-based measurements of mPA-D and mPA-D/aAo-D have the potential to screen patients with suspicious PoPH in clinical practice focused on portal hypertension.

B-flow/spatiotemporal image correlation M-mode: novel ultrasound method that detects decrease in spiral artery luminal diameter in first trimester in primate model of impaired spiral artery remodeling.

OBJECTIVE: To determine if B-flow/spatiotemporal image correlation (STIC) M-mode ultrasonography detects a decrease in spiral artery luminal diameter and volume flow during the first trimester in a non-human primate model of impaired spiral artery remodeling (SAR). METHODS: Pregnant baboons were treated daily with estradiol benzoate on days 25-59 of the first trimester (term, 184 days), or remained untreated. On day 60 of gestation, spiral artery luminal diameter (in seven untreated and 12 estradiol-treated baboons) and volume flow (in four untreated and eight estradiol-treated baboons) were quantified by B-flow/STIC M-mode ultrasonography. In addition, in 15 untreated and 18 estradiol-treated baboons, the percent of spiral arteries remodeled by extravillous trophoblasts was quantified ex vivo by immunohistochemical image analysis on placental basal plate tissue collected via Cesarean section on day 60. Findings were compared between treated and untreated animals. The correlation between spiral artery luminal diameter and percent of SAR was assessed in three untreated and six estradiol-treated baboons which underwent both B-flow/STIC M-mode ultrasound and quantification of SAR. RESULTS: The proportion of spiral arteries greater than 50 µm in diameter remodeled by extravillous trophoblasts was 70% lower in estradiol-treated baboons than in untreated animals (P = 0.000001). Spiral artery luminal diameter in systole and diastole, as quantified by B-flow/STIC M-mode in the first trimester of pregnancy, was 31% (P = 0.014) and 50% (P = 0.005) lower, respectively, and volume flow was 85% lower (P = 0.014), in SAR-suppressed baboons compared with untreated animals. There was a significant correlation between spiral artery luminal diameter as quantified by B-flow/STIC M-mode ultrasonography and the percent of SAR (P < 0.05). CONCLUSION: B-flow/STIC M-mode ultrasonography provides a novel real-time non-invasive method to detect a decrease in uterine spiral artery luminal diameter and volume flow during the cardiac cycle, reflecting decreased distensibility of the vessel wall, in the first trimester in a non-human primate model of defective SAR. © 2021 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Artery diameter ratio after recanalization in endovascular therapy for acute ischemic stroke: a new predictor of clinical outcomes.

PURPOSE: This study aimed to investigate the relationship between the artery diameter ratio (ADR) after recanalization and clinical outcomes. METHODS: Patients with middle cerebral artery occlusion confirmed by DSA from 1 January 2018, to 31 December 2019, were retrospectively analyzed. All patients confirmed TICI grade 2b or 3. The ADR was calculated as M2 segment diameter/M1 segment diameter. Multivariate regression analysis was used to describe clinical outcomes of two groups (ADR < 0.6 and ≥ 0.6). ROC curves were used to compare different models and find the best cutoff. RESULTS: A total of 143 patients were included in the study, including 77 males and 66 females, with an average age of 67.79 ± 12 years. The NIHSS at discharge was significantly higher in the ADR < 0.6 group than another group (mean, 16.37 vs. 6.19, P < 0.001). At 90 days, the cases of functional independence was significantly less in the ADR < 0.6 group (20.97% vs. 83.95%, OR 0.05, 95% CI 0.02-0.12, P < 0.001). The ADR < 0.6 group had a higher incidence of cerebral edema (P = 0.027) and sICH (P = 0.038). The ADR had the strongest power to distinguish mRS > 2 (AUC = 0.851) and DC (AUC = 0.805), and the best cutoff value are 0.6 (specificity 85.19%, sensitivity 75.81%) and 0.58 (specificity 65.96%, sensitivity 100%), respectively. CONCLUSION: The low ADR is associated with poor outcomes. The decrease in ADR may be an indirect manifestation of the loss of cerebrovascular autoregulation.

Bronchial artery diameter in massive hemoptysis in cystic fibrosis.

BACKGROUND: Massive hemoptysis is a rare but potentially life-threatening condition of patients with cystic fibrosis (CF) and advanced pulmonary disease. Hypertrophied bronchial arteries are understood to cause massive hemoptysis when rupturing. Risk factors to predict massive hemoptysis are scarce and bronchial artery diameters are not part of any scoring system in follow-up of patients with CF. Aim of this study was to correlate bronchial artery diameter with massive hemoptysis in CF. METHODS: Bronchial artery and non-bronchial systemic artery diameters were measured in contrast enhanced computed tomography (CT) scans in patients with massive hemoptysis and compared to patients with end-stage CF and no history of hemoptysis. Demographic and clinical data and side of bronchial artery/non-bronchial systemic artery hypertrophy and coil embolization were documented. RESULTS: In this retrospective multicenter study 33 patients with massive hemoptysis were included for bronchial artery/non-bronchial systemic artery diameter measurements, (13 female, 20 male, median age 30 years (18-55)). Bronchial artery diameters were significantly larger in the case group than in the control group with median 4 mm (2.2-8.2 mm), and median 3 mm (1-7 mm), respectively (p = 0.002). Sensitivity of bronchial arteries ≥ 3.5 mm to be associated with hemoptysis was 0.76 and specificity 0.71 with ROC creating an area under the curve of 0.719. If non-bronchial systemic arteries were present, they were considered culprit and embolized in 92% of cases. CONCLUSION: Bronchial arteries ≥ 3.5 mm and presence of hypertrophied non-bronchial systemic arteries correlate with massive hemoptysis in patients with CF and might serve as risk predictor for massive hemoptysis. Therefore, in patients with advanced CF we propose CT scans to be carried out as CT angiography to search for bronchial arteries ≥ 3.5 mm and for hypertrophied non-bronchial systemic arteries as possible risk factors for massive hemoptysis.

Towards Estimating Arterial Diameter Using Bioimpedance Spectroscopy: A Computational Simulation and Tissue Phantom Analysis.

This paper improves the accuracy of quantification in the arterial diameter-dependent impedance variance by altering the electrode configuration. The finite element analysis was implemented with a 3D human wrist fragment using ANSYS Electronics Desktop, containing fat, muscle, and a blood-filled radial artery. Then, the skin layer and bones were stepwise added, helping to understand the dielectric response of multi-tissues and blood flow from 1 kHz to 1 MHz, the current distribution throughout the wrist, and the optimisation of electrode configurations for arterial pulse sensing. Moreover, a low-cost wrist phantom was fabricated, containing two components: the surrounding tissue simulant (20 wt % gelatine power and 0.017 M sodium chloride (NaCl) solution) and the blood simulant (0.08 M NaCl solution). The blood-filled artery was constricted using a desktop injection pump, and the impedance change was measured by the Multi-frequency Impedance Analyser (MFIA). The simulation revealed the promising capabilities of band electrodes to generate a more uniform current distribution than the traditional spot electrodes. Both simulation and phantom experimental results indicated that a longer spacing between current-carrying (CC) electrodes with shorter spacing between pick-up (PU) electrodes in the middle could sense a more uniform electric field, engendering a more accurate arterial diameter estimation. This work provided an improved electrode configuration for more accurate arterial diameter estimation from the numerical simulation and tissue phantom perspectives.

Time Course of Coronary Artery Aneurysms in Kawasaki Disease.

OBJECTIVES: To determine the timeframe in which coronary artery aneurysms (CAAs) caused by Kawasaki disease reach their maximum diameter, the timeframe in which they regress to normal size, and the cutoff point of the diameter for CAA regression. STUDY DESIGN: We reviewed 195 CAAs of the right coronary artery, left anterior descending artery, and left coronary artery measured by 2-dimensional echocardiography ≥5 times for 1 year after Kawasaki disease in 84 patients using medical records from 1995. The maximum diameters of CAAs were investigated retrospectively. The time to CAA regression using both absolute diameter and Z score were investigated. The cutoff points of the diameter of CAA regression in the 2 classifications were identified using receiver operator characteristic curve analysis. One year after Kawasaki disease, a CAA of <3.0 mm in absolute diameter and a Z score of <2.5 were defined as CAA regression. RESULTS: The time when CAAs reached their maximum diameter ranged from 11 days to 87 days, with a median of 35 days (n = 195). The time to CAA regression ranged from 41 to 386 days, with a median of 136 days in the absolute diameter classification (n = 92); 78% of CAA regression regressed by 200 days. The cutoff point for CAA regression at one year was 5.7 mm for the absolute diameter (area under the curve, 0.887; P < .0001; n = 190) and 9.5 for the Z score (area under the curve, 0.815; P < .0001; n = 195). CONCLUSIONS: CAAs with a smaller diameter regressed earlier, and most CAAs of <6 mm regressed by 6 months after Kawasaki disease.

Measuring the ratio of femoral vein diameter to femoral artery diameter by ultrasound to estimate volume status.

BACKGROUND: Currently, the accepted effective method for assessing blood volume status, such as measuring central venous pressure (CVP) and mean pulmonary artery pressure (mPAP), is invasive. The purpose of this study was to explore the feasibility and validity of the ratio of the femoral vein diameter (FVD) to the femoral artery diameter (FAD) for predicting CVP and mPAP and to calculate the cut-off value for the FVD/FAD ratio to help judge a patient's fluid volume status. METHODS: In this study, 130 patients were divided into two groups: in group A, the FVD, FAD, and CVP were measured, and in group B, the FVD, FAD, and mPAP were measured. We measured the FVD and FAD by ultrasound. We monitored CVP by a central venous catheter and mPAP by a Swan-Ganz floating catheter. Pearson correlation coefficients were calculated. The best cut-off value for the FVD/FAD ratio for predicting CVP and mPAP was obtained according to the receiver operating characteristic (ROC) curve. RESULTS: The FVD/FAD ratio was strongly correlated with CVP (R = 0.87, P < 0.0000) and mPAP (R = 0.73, P < 0.0000). According to the ROC curve, an FVD/FAD ratio ≥ 1.495 had the best test characteristics to predict a CVP ≥ 12 cmH2O, and an FVD/FAD ratio ≤ 1.467 had the best test characteristics to predict a CVP ≤ 10 cmH2O. An FVD/FAD ratio ≥ 2.03 had the best test characteristics to predict an mPAP ≥ 25 mmHg. According to the simple linear regression curve of the FVD/FAD ratio and CVP, when the predicted CVP ≤ 5 cmH2O, the FVD/FAD ratio was ≤ 0.854. CONCLUSION: In this study, the measurement of the FVD/FAD ratio obtained via ultrasound was strongly correlated with CVP and mPAP, providing a non-invasive method for quickly and reliably assessing blood volume status and providing good clinical support.

Evaluation of the factors related to difficult ultrasound-guided radial artery catheterization in small children: A prospective observational study.

BACKGROUND: Although ultrasound guidance has significantly improved the success rate of radial artery catheterization, the failure rate in children is still high. For the further improvement of success rate, we prospectively evaluated the factors that make ultrasound-guided radial artery catheterization difficult in children under two years old. METHODS: From October 2018 to September 2019, patients who required radial artery catheterization for surgery were enrolled. After collecting the anatomical characteristics of the radial artery using ultrasound at the puncture site, ultrasound-guided radial artery catheterization was performed by one experienced anaesthesiologist. The primary outcome was to identify the factors related to the first attempt failure. The factors associated with the total duration of the procedure until success were also evaluated. RESULTS: A total of 183 children were included in the analysis. A radial artery cross-sectional area of ≤1 mm2 (odds ratio [OR] = 5.26; 95% confidence interval [CI], 2.48-11.18; P < .0001) and the presence of an anomalous radial artery branch (OR = 3.37; 95% CI, 1.43-7.95; P = .005) were independent predictors of first-attempt failure during ultrasound-guided radial artery catheterization. The total procedure time was also negatively associated with the small cross-sectional area (P < .001). CONCLUSIONS: A cross-sectional area of ≤ 1 mm2 and the presence of an anomalous branch of radial artery significantly increased the difficulty of ultrasound-guided radial artery catheterization in children under two years old. In patients of these ages, pre-procedural ultrasound scanning to find an optimal site for catheterization may increase the first-attempt success rate although further studies are needed to verify our results. TRIAL REGISTRATION: Clinical Research Information Service (https://crits.nih.go.kr, October 6, 2018 [KCT0003239]; Principle investigator: Jong-Hwan Lee).

Establishing an appropriate Z score regression equation for Chinese pediatric coronary artery echocardiography: a multicenter prospective cohort study.

BACKGROUND: Z score utility is emphasized in classifying coronary artery lesions in Kawasaki disease patients. The present study is the largest such multicenter Chinese pediatric study about coronary artery diameter reference values and Z score regression equation to date. It is useful in Chinese pediatric echocardiography. METHODS: A multicenter cohort was assembled, which consisted of 852 healthy children between 1 month and 17 years of age, ten children were excluded because their ultrasound images were not clear, or lost in following up. Diameters of the right coronary artery, left coronary artery, and left anterior descending coronary artery were assessed using echocardiography. Data were body surface area (BSA)-corrected using BSA calculated via either the Stevenson BSA formula or the Haycock BSA formula. Coronary artery diameter reference values and Z score regression equations were established for use in the Chinese pediatric population. RESULTS: No difference was observed between coronary artery diameter data corrected using BSAste or BSAhay. Of the five assessed regression models, the exponential model exhibited the best fit and was therefore selected as the basis for derivation of the SZ method. When comparing Z scores, those produced by the SZ method conformed to the standard normal distribution, while those produced by the D method did not. In addition, there was a statistically significant difference between Z scores produced by the SZ and D methods (P < 0.05). CONCLUSIONS: Coronary artery diameter reference values for echocardiography were successfully established for use in the Chinese pediatric population, and a Z score regression equation more suitable for clinical use in this population was successfully developed.

Evaluation of distal radial artery cross-sectional internal diameter in neonates and infants by ultrasound and adequate selection of an intra-arterial catheter size.

BACKGROUND: Radial artery catheterization in neonates, infants, and young children is a common and useful invasive procedure that brings technical placement challenges and potential complications due to the small diameter size of the radial artery in these patients. The aim of this study is to determine appropriate catheter sizes in infants up to 6 months of age. MATERIALS AND METHODS: A total of fifty infants undergoing general anesthesia or hospitalized in the neonatal intensive care unit were included. Images of the radial artery diameter were obtained from the infant's wrist using Philips EPIQ Diagnostic Ultrasound System CVX Release 4.0. All images obtained were distal in the forearm, medial to the border of the styloid process of the radius, at the point of maximal impulse of the radial artery, and with the wrist at a 45-degree angle position. We recorded postmenstrual age, chronological age, gender, weight, location, comorbidities, medications, weight, and vital signs of each individual. RESULTS: In this single cohort study of 50 children whose ages ranged from 0 to 6 months chronological age, their radial artery diameters were averaged proportionally to their weight and age. Use of a 22G catheter would result in 100% occlusion of the diameter of the artery in most study subjects. Use of a 24G catheter would result in a range of 75%-99% occlusion depending on weight, postmenstrual age, and chronological age of the infants. CONCLUSIONS: In view of these findings, we recommend using US to measure the diameter of the radial artery and choose the most appropriate catheter size before proceeding with US-guidance for radial artery cannulation in infants. This will prevent inappropriate sizing of the catheter and the thrombotic complications this can incur.

Changes in Coronary Aneurysm Diameters After Acute Kawasaki Disease from Infancy to Adolescence.

We clarified the changes in coronary artery diameters based on the degree of coronary artery involvement immediately after acute Kawasaki disease (KD). Two hundred sixteen coronary arteries in 85 patients after KD examined by two-dimensional echocardiography were reviewed from 1995. The maximal internal diameters were measured at 2 months, 1 year, 3 years, 10 years and 15 years after KD. The coronary arteries were divided into five groups based on the absolute diameter at 2 months, as well as six groups based on the Z score at 2 months. The maximum diameters were compared at 2 months with those during follow-up in each group. The numbers of right coronary, left anterior descending, left coronary, and left circumflex arteries were 84, 73, 55 and 4, respectively. There was a significant relationship between the maximum internal diameter at 2 months and subsequent changes in the maximum diameters after KD in the late period in both groups (p < 0.0001). The maximum diameters of coronary artery aneurysms (CAAs) ≥ 8.0 mm at 2 months did not change significantly after 1 year, however, the maximum diameter of CAAs < 8.0 mm was significantly smaller in the late period (p < 0.05). Coronary arteries without dilatation at 2 months after KD grew normally. CAAs with a maximum diameter ≥ 6.0 mm and Z score ≥ 7.5 at 2 months after KD persisted in adolescents, whereas coronary arteries with diameters < 6.0 mm and Z score < 7.5 could be within normal ranges in the late period.

Bio-Impedance Sensor for Real-Time Artery Diameter Waveform Assessment.

The real-time artery diameter waveform assessment during cardio cycle can allow the measurement of beat-to-beat pressure change and the long-term blood pressure monitoring. The aim of this study is to develop a self-calibrated bio-impedance-based sensor, which can provide regular measurement of the blood-pressure-dependence time variable parameters such as the artery diameter waveform and the elasticity. This paper proposes an algorithm based on analytical models which need prior geometrical and physiological patient parameters for more appropriate electrode system selection and hence location to provide accurate blood pressure measurement. As a result of this study, the red cell orientation effect contribution was estimated and removed from the bio-impedance signal obtained from the artery to keep monitoring the diameter waveform correspondence to the change of blood pressure.

Radial artery diameterand and age related functional maturation of the radio-cephalic arteriovenous fistula.

BACKGROUND: Previous studies have not described the relationship between reducing radial artery diameter as well as increasing age and functional maturation of the radio-cephalic arteriovenous fistula (RCAVF) and no data identify these as linear relationship. The objective of this study was to perform trend analysis to assess these aspects. METHODS: Our retrospective cohort study enrolled and analyzed 353 follow-up cases that underwent first AVF creation. The artery and vein sizes were measured by ultrasound. We performed follow-up, a minimum of 3 months after surgery. Multivariable logistic regression analysis was used to identify independent risk factors inmaturation. Participant age was categorized into four groups (age ≤ 29, 30-49, 50-69, and 70-90 years). Radial artery diameter was categorized into four groups (≤ 1.9, >1.9 and ≤ 2.1, >2.1 and ≤ 2.4, >2.4 mm) according to median and interquartile ranges. We adjusted for confounders in four logistic models, and primary analyses were based on building ordered category models and tested P values for trends to estimate the relationship of radial artery diameter and each 20-year increase in age with risk of maturation. RESULTS: The mature RCAVF group included 301 cases, and the immature group included 52 cases. Radial artery diameter, age, and diabetes were independent risk factors of maturation. Odds ratios (ORs) associated with maturation reduced with increasing age, while ORs increased with increasing radial artery diameter. P values for trends(<0.05) were observed in all four models. A reduction in radial artery diameter and higher age were significantly associated with a higher incidence of immaturity after adjusting the multivariate models. The risks of immaturation were increased by more than 1.54 fold for each 20-year increase and increased by more than 1.34 fold for the smaller radial artery diameter group. CONCLUSION: Our findings suggest that a significantly higher immaturity risk of RCAVF was associated with increasing age and a reduction in radial artery diameter. Our study identified a linear exposure-response relationship of age and radial artery diameter with immaturity incident. A careful selection of patients will be helpful in improving AVF functional maturation.

Investigating Electrical Impedance Spectroscopy for Estimating Blood Flow-Induced Variations in Human Forearm.

This work aims to investigate the feasibility of employing multi-frequency bioimpedance analysis for hemodynamic assessment. Towards this, we aim to explore one of its implementations, electrical impedance spectroscopy (EIS), for estimating changes in radial artery diameter due to blood flow. Following from our previous investigations, here, we use a commercial device-the Quadra® Impedance Spectroscopy device-for impedance measurements of the forearm of three subjects under normal conditions and occluding the artery with a cuff. This was performed simultaneously with ultrasound measurements as a reference. The impedance spectra were measured over time, yielding waveforms reflecting changes due to blood flow. Contributions from the fat/muscle domains were accounted for using the occluded impedance response, resulting in arterial impedance. A modified relationship was approximated to calculate the diameter from the arterial impedance, which showed a similarity with ultrasound measurements. Comparison with the ultrasound measurements revealed differences in phase and amplitude, primarily due to the approximated relationship between impedance and diameter and neglecting the impedance phase analysis. This work shows the potential of EIS, with improvements, towards estimating blood flow-induced variation in arteries. Further analysis and improvements could help place this technology in mainstream clinical practice for hemodynamic monitoring.

Effect of pistachio on brachial artery diameter and flow-mediated dilatation: A systematic review and meta-analysis of randomized, controlled-feeding clinical studies.

BACKGROUND: Results of previous clinical trials evaluating the effect of pistachio supplementation on endothelial reactivity (ER) are controversial. AIMS: We aimed to assess the impact of pistachio on ER through systematic review of literature and meta-analysis of available randomized, controlled-feeding clinical studies (RCTs). METHODS: The literature search included SCOPUS, PubMed-Medline, ISI Web of Science and Google Scholar databases up to 1st August 2017 to identify RCTs investigating the impact of pistachio on ER. Two independent reviewers extracted data on study characteristics, methods and outcomes. Overall, the impact of pistachio on ER was reported in 4 trials. RESULTS: The meta-analysis did not suggest a significant change in brachial artery flow-mediated dilatation (FMD) (WMD: +0.28%; 95%CI: -0.58, 1.13; p = 0.525) while brachial artery diameter (BAD) improved (WMD: +0.04%; 95%CI: 0.03, 0.06; p<0.001) following pistachios consumption. CONCLUSION: The present meta-analysis suggests a significant effect of pistachios on ER, affecting BAD but not FMD.

Egg-and-Banana Sign: A Novel Diagnostic CT Marker for Pulmonary Hypertension.

OBJECTIVE: The purpose of this study was to retrospectively determine whether the egg-and-banana sign, defined as the visualization of the main pulmonary artery (PA) at the level of the aortic arch, is a sensitive and specific diagnostic marker for pulmonary hypertension. MATERIALS AND METHODS: A total of 186 patients who, between January 2014 and July 2017, received right heart catheterizations and underwent CT studies that included the aortic arch within 140 days of catheterization were evaluated in this retrospective study. Of these patients, 127 had pulmonary hypertension (PH), and 59 who did not have PH served as control subjects. Two blinded radiologists reviewed each study for the egg-and-banana sign. The diameters of the main PA and ascending aorta were also measured. Contingency tables, ROC curves, and a t test were used for statistical analysis. RESULTS: The egg-and-banana sign was associated with a higher mean PA pressure, a higher ratio of the diameter of the PA to the diameter of the ascending aorta (Ao) (hereafter referred to as the "PA-to-Ao ratio"), and a larger PA diameter (p < 0.006). It had a specificity of 85% and a positive predictive value of 85%. When the egg-and-banana sign was used in combination with a main PA diameter larger than 29 mm and a PA-to-Ao ratio greater than 1, its specificity increased to 91% and 93%, respectively. When considered as individual markers, the PA diameter had a high sensitivity (80%; AUC value, 0.74) and the PA-to-Ao ratio had a high specificity (81%; AUC value, 0.73) for PH. Moderate correlations were noted between PA pressure and PA diameter (r = 0.37) and between PA pressure and PA-to-Ao ratio (r = 0.43). CONCLUSION: The egg-and-banana sign has a high specificity and PPV for PH. Specificity increased when the sign was used in combination with other classic CT markers.