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Vascular Medicine (London, England) Oct 2023Duplex ultrasound examinations of the mesenteric and renal circulations are commonly used to detect disease as well as to follow up patients after open surgery or... (Review)
Review
Duplex ultrasound examinations of the mesenteric and renal circulations are commonly used to detect disease as well as to follow up patients after open surgery or endovascular intervention. The aims of this review were to present essential elements of these duplex ultrasound examinations as well as conduct a literature review of diagnostic criteria. Documentation of appropriate images and data will aid in an accurate interpretation. Spectral Doppler waveforms from various segments of these arterial systems can contribute both direct and indirect evidence of the presence of disease. Various studies have validated the duplex ultrasound diagnostic criteria which more recently have expanded to include specific criteria for stented vessels. This review presents a summary of the fundamental exam components and diagnostic criteria utilized for mesenteric and renal duplex ultrasound.
Topics: Humans; Ultrasonography, Doppler, Duplex; Arteries; Stents
PubMed: 37259501
DOI: 10.1177/1358863X231172247 -
Journal of Biomedical Materials... Apr 2024Synthetic vascular grafts are commonly used in patients with severe occlusive arterial disease when autologous grafts are not an option. Commercially available synthetic... (Review)
Review
Synthetic vascular grafts are commonly used in patients with severe occlusive arterial disease when autologous grafts are not an option. Commercially available synthetic grafts are confronted with challenging outcomes: they have a lower patency rate than autologous grafts and are currently unable to promote arterial regeneration. Polyglycerol sebacate (PGS), a non-toxic polymer with a tunable degradation profile, has shown promising results as a small-diameter vascular graft component that can support the formation of neoarteries. In this review, we first present an overview of the synthesis and modification of PGS followed by an examination of its mechanical properties. We then report on the performance, degradation, regeneration, and remodeling of PGS-based small-diameter vascular grafts, with a focus on efforts to reduce thrombosis, prevent dilation, and promote cellular residency and extracellular matrix regeneration that resembles the native artery in spatial distribution and organization. We also highlight recent advances in the incorporation of novel in situ cell sources for arterial regeneration and their potential application in PGS-based vascular grafts. Finally, we compare vascular grafts fabricated using PGS-based materials with other elastomeric alternatives.
Topics: Humans; Polymers; Arteries; Blood Vessel Prosthesis; Regeneration; Glycerol
PubMed: 37345954
DOI: 10.1002/jbm.a.37583 -
Acta Biomaterialia Oct 2023High failure rates present challenges for surgical and interventional therapies for peripheral artery disease of the femoropopliteal artery (FPA). The FPA's demanding...
High failure rates present challenges for surgical and interventional therapies for peripheral artery disease of the femoropopliteal artery (FPA). The FPA's demanding biomechanical environment necessitates complex interactions with repair devices and materials. While a comprehensive understanding of the FPA's mechanical characteristics could improve medical treatments, the viscoelastic properties of these muscular arteries remain poorly understood, and the constitutive model describing their time-dependent behavior is absent. We introduce a new viscoelastic constitutive model for the human FPA grounded in its microstructural composition. The model is capable of detailing the contributions of each intramural component to the overall viscoelastic response. Our model was developed utilizing fractional viscoelasticity and tested using biaxial experimental data with hysteresis and relaxation collected from 10 healthy human subjects aged 57 to 65 and further optimized for high throughput and automation. The model accurately described the experimental data, capturing significant nonlinearity and hysteresis that were particularly pronounced circumferentially, and tracked the contribution of passive smooth muscle cells to viscoelasticity that was twice that of the collagen fibers. The high-throughput parameter estimation procedure we developed included a specialized objective function and modifications to enhance convergence for the common exponential-type fiber laws, facilitating computational implementation. Our new model delineates the time-dependent behavior of human FPAs, which will improve the fidelity of computational simulations investigating device-artery interactions and contribute to their greater physical accuracy. Moreover, it serves as a useful tool to investigate the contribution of arterial constituents to overall tissue viscoelasticity, thereby expanding our knowledge of arterial mechanophysiology. STATEMENT OF SIGNIFICANCE: The demanding biomechanical environment of the femoropopliteal artery (FPA) necessitates complex interactions with repair devices and materials, but the viscoelastic properties of these muscular arteries remain poorly understood with the constitutive model describing their time-dependent behavior being absent. We hereby introduce the first viscoelastic constitutive model for the human FPA grounded in its microstructures. This model was tested using biaxial mechanical data collected from 10 healthy human subjects between the ages of 57 to 65. It can detail the contributions of each intramural component to the overall viscoelastic response, showing that the contribution of passive smooth muscle cells to viscoelasticity is twice that of collagen fibers. The usefulness of this model as tool to better understand arterial mechanophysiology was demonstrated.
Topics: Humans; Middle Aged; Aged; Femoral Artery; Peripheral Arterial Disease; Viscosity; Collagen; Elasticity; Stress, Mechanical; Models, Biological; Biomechanical Phenomena
PubMed: 37699504
DOI: 10.1016/j.actbio.2023.09.007 -
Computer Methods and Programs in... Oct 2023The blood pressure and flow waveforms carry valuable information about the condition of the cardiovascular system and a patient's health. Waveform analysis in health and...
BACKGROUND AND OBJECTIVE
The blood pressure and flow waveforms carry valuable information about the condition of the cardiovascular system and a patient's health. Waveform analysis in health and pathological conditions can be performed in the time or frequency domains; the information to be emphasised defines the use of either domain. However, physicians are more familiar with the time domain, and the changes in the waveforms due to cardiovascular diseases and ageing are better characterised in such domain. On the other hand, the analysis of the vascular and geometrical variables determining the signatures in the frequency response of local vascular anomalies, such as aneurysms and stenoses, has not been thoroughly explored. This paper aims to characterise the signatures of obstructions (stenoses) and expansions (aneurysms) in the frequency response of tapered arteries.
METHODS
The first step in our methodology was to incorporate the viscous response of the arterial wall into a one-dimensional elastic formulation that solves the governing equations in the frequency domain. As a second step, we imposed a volumetric flow excitation in arteries simulating the aorta with increasing geometry complexity: from straight to tapered arteries with local expansions or obstructions; and we assessed the frequency response.
RESULTS
We found that the obstructions and expansions cause characteristic signatures in an artery's frequency response that are distinguishable from a health condition. The signatures of obstruction and expansions differ; the obstructions increase the magnitude of fundamental frequency and work as a close boundary condition. On the other hand, the expansions diminish the fundamental frequency and work as an open boundary condition. Furthermore, such signatures correlate to the distance between the artery's inlet and the anomaly's starting point and have the potential to pinpoint abnormalities non-invasively.
CONCLUSIONS
We found that the obstructions and expansions cause characteristic signatures in an artery's frequency response that have the potential to detect and follow up on the development of vascular abnormalities. For the latter purpose, constant monitoring may be required; despite this not being a common clinical practice, the new wearable technology offers the possibility of continuous monitoring of biophysical markers such as the pressure waveform.
Topics: Constriction, Pathologic; Vascular Diseases; Humans; Arteries
PubMed: 37336151
DOI: 10.1016/j.cmpb.2023.107628 -
British Journal of Anaesthesia Oct 2023Arterial catheterisation in children can be challenging and time-consuming. We aimed to compare the success rates of ultrasound-guided arterial catheterisation utilising... (Randomized Controlled Trial)
Randomized Controlled Trial
Comparison of radial, dorsalis pedis, and posterior tibial arteries for ultrasound-guided arterial catheterisation with dynamic needle tip positioning in paediatric patients: a randomised controlled trial.
BACKGROUND
Arterial catheterisation in children can be challenging and time-consuming. We aimed to compare the success rates of ultrasound-guided arterial catheterisation utilising the short-axis out-of-plane approach with dynamic needle tip positioning in the radial, dorsalis pedis, and posterior tibial arteries in paediatric patients. We also examined the factors influencing the catheterisation success using dynamic needle tip positioning.
METHODS
Paediatric patients (aged <3 yr) undergoing cardiac surgery were randomly assigned to three groups based on puncture sites: radial artery (Group R), dorsalis pedis artery (Group D), and posterior tibial artery (Group P). The first-attempt and overall success rates of arterial catheterisation were compared, followed by multiple logistic regression analysis (dependent variable: first-attempt success; independent variables: body weight, diameter and depth of the artery, targeted artery, and trisomy 21).
RESULTS
The study included 270 subjects (n=90 per group). There was no significant difference in the first-attempt (Group R: 82%, Group D: 76%, and Group P: 81%) and overall success rates (Group R: 94%, Group D: 93%, and Group P: 91%) among the three groups. The diameter of the artery (per 0.1 mm) (odds ratio: 1.32, 95% confidence interval: 1.09-1.60) and trisomy 21 (odds ratio: 0.43, 95% confidence interval: 0.20-0.92) were independent predictors of first-attempt success or failure.
CONCLUSION
The first-attempt and overall success rates of arterial catheterisation of the dorsalis pedis and posterior tibial arteries were not inferior to those in the radial artery when using dynamic needle tip positioning. These two lower extremity peripheral arteries present viable alternative catheterisation sites in paediatric patients.
CLINICAL TRIAL REGISTRATION
UMIN000042847.
Topics: Humans; Child; Tibial Arteries; Down Syndrome; Radial Artery; Lower Extremity; Ultrasonography, Interventional
PubMed: 37604735
DOI: 10.1016/j.bja.2023.07.022 -
Psychiatry Research. Neuroimaging Aug 2023Generalized anxiety disorder (GAD) is the least studied among anxiety disorders. Therefore, we aimed to compare the cervical blood flow velocities using doppler...
BACKGROUND
Generalized anxiety disorder (GAD) is the least studied among anxiety disorders. Therefore, we aimed to compare the cervical blood flow velocities using doppler ultrasonography in untreated chronic GAD patients and healthy individuals.
MATERIAL AND METHODS
In this study, thirty-eight GAD patients were enrolled. And thirty-eight healthy volunteers were recruited as control participants. The common carotid artery (CCA), internal carotid artery (ICA), and vertebral artery (VA) of both sides were explored. Also, we trained machine learning models based on cervical arteries characteristics to diagnose GAD patients.
RESULTS
Patients with chronic untreated GAD showed a significant increase in peak systolic velocity (PSV) bilaterally in the CCA and the ICA (P value < 0.05). In GAD patients, the end-diastolic velocity (EDV) of bilateral CCA, VA, and left ICA was significantly decreased. The Resistive Index (RI) showed a significant increase in all patients with GAD. Moreover, the Support Vector Machine (SVM) model showed the best accuracy in identifying anxiety disorder.
CONCLUSION
GAD is associated with hemodynamic alterations of extracranial cervical arteries. With a larger sample size and more generalized data, it is possible to make a robust machine learning-based model for GAD diagnosis.
Topics: Humans; Carotid Artery, Internal; Carotid Artery, Common; Hemodynamics; Blood Flow Velocity; Anxiety Disorders
PubMed: 37229961
DOI: 10.1016/j.pscychresns.2023.111654 -
Vasomotion in human arteries and their regulations based on ion channel regulations: 10 years study.Journal of Cellular Physiology Sep 2023Vasomotion is the oscillation of vascular tone which gives rise to flow motion of blood into an organ. As is well known, spontaneous contractile organs such as heart,...
Vasomotion is the oscillation of vascular tone which gives rise to flow motion of blood into an organ. As is well known, spontaneous contractile organs such as heart, GI, and genitourinary tract produce rhythmic contraction. It imposes or removes pressure on their vessels alternatively for exchange of many substances. It was first described over 150 years ago, however the physiological mechanism and pathophysiological implications are not well understood. This study aimed to elucidate underlying mechanisms and physiological function of vasomotion in human arteries. Conventional contractile force measurement, immunohistochemistry, and Western blot analysis were employed to study human left gastric artery (HLGA) and uterine arteries (HUA). RESULTS: Circular muscle of HLGA and/or HUA produced sustained tonic contraction by high K (50 mM) which was blocked by 2 µM nifedipine. Stepwise stretch and high K produced nerve-independent spontaneous contraction (vasomotion) (around 45% of tested tissues). Vasomotion was also produced by application of BayK 8644, 5-HT, prostagrandins, oxytocin. It was blocked by nifedipine (2 µM) and blockers of intracellular Ca stores. Inhibitors of Ca -activated Cl channels (DIDS and/or niflumic acid) and ATP-sensitive K (K ) channels inhibited vasomotion reversibly. Metabolic inhibition by sodium cyanide (NaCN) and several neuropeptides also regulated vasomotion in K channel-sensitive and -insensitive manner. Finally, we identified TMEM16A Ca -activated Cl channels and subunits of K channels (Kir 6.1/6.2 and sulfonylurea receptor 2B [SUR2B]), and c-Kit positivity by Western blot analysis. We conclude that vasomotion is sensitive to TMEM16A Ca -activated Cl channels and metabolic changes in human gastric and uterine arteries. Vasomotion might play an important role in the regulation of microcirculation dynamics even in pacemaker-related autonomic contractile organs in humans.
Topics: Humans; Ion Channels; Nifedipine; Uterine Artery; Arteries; Isometric Contraction
PubMed: 37672477
DOI: 10.1002/jcp.31067 -
No Shinkei Geka. Neurological Surgery May 2024Thorough understanding of the vascular anatomy, including embryological development of vessels is important to safely perform endovascular procedures. The posterior... (Review)
Review
Thorough understanding of the vascular anatomy, including embryological development of vessels is important to safely perform endovascular procedures. The posterior cerebral and anterior choroidal arteries are embryologically complementary, which suggests a potential network. Numerous perforators originate from the posterior communicating and posterior cerebral arteries. The tuberothalamic artery arising from the posterior communicating artery and the thalamoperforating artery, which originates from the P1 segment of the posterior cerebral artery are clinically important because occlusion of these vessels can precipitate severe infarction. It is clinically important to be aware that the branching pattern of perforators differs based on the fusion type of the basilar tip. The balloon occlusion and Allcock test are useful to predict ischemic tolerance in cases of intentional artery occlusion. However, accurate prediction remains challenging, and a definitive evaluation method is unavailable. Flow disturbances in the cortical territory and local perforator impairment require close attention in cases of intentional artery occlusion.
Topics: Humans; Posterior Cerebral Artery; Endovascular Procedures
PubMed: 38783495
DOI: 10.11477/mf.1436204945 -
Anatomical Science International Mar 2024During the anatomical dissection of the pelvis, a duplication of the uterine artery was identified unilaterally on the left side in a 59-year-old Korean female cadaver....
During the anatomical dissection of the pelvis, a duplication of the uterine artery was identified unilaterally on the left side in a 59-year-old Korean female cadaver. The first uterine artery was found to arise directly from the anterior division of the internal iliac artery and supply the upper uterine body and tube. The second uterine artery shared a common stem with the superior and inferior vesical arteries, supplying the lower uterine body. The external diameter of each uterine artery at its origin on the left side was smaller than that of the right uterine artery. One vaginal artery was identified to arise from the left internal pudendal artery. Embryologically, a duplicated uterine artery could imply the presence of two primordial arteries separately supplying the cranial and caudal parts of the Müllerian duct during the early fetal period. This case of variational anatomy is noteworthy: clinicians could elucidate it and successfully perform uterine artery embolization or hysterectomy with minimal complications.
Topics: Female; Humans; Middle Aged; Uterine Artery; Anatomic Variation; Pelvis; Uterus; Iliac Artery
PubMed: 38091200
DOI: 10.1007/s12565-023-00752-4 -
Eye (London, England) Dec 2023To study the orbital perfusion parameters of ophthalmic artery (OA) and central retinal artery (CRA) in inactive TED and the changes following surgical decompression. (Clinical Trial)
Clinical Trial
PURPOSE
To study the orbital perfusion parameters of ophthalmic artery (OA) and central retinal artery (CRA) in inactive TED and the changes following surgical decompression.
METHODS
Non-randomised clinical trial. 24 inactive moderate-to-severe TED orbits of 24 euthyroid cases underwent surgical decompression and examined again at 3 months. The peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistivity index (RI) of OA and CRA were evaluated using colour doppler imaging and normative database was established using 18 healthy controls.
RESULTS
The mean age was 39.38 ± 12.56 years and male: female ratio was 1: 1.18. Intraocular pressure was higher, and CRA-PSV, CRA-RI, OA-PSV, and OA-EDV were lower in TED in comparison to heathy orbits. The CRA-PSV, CRA-EDV, OA-PSV, and OA-EDV negatively correlated with proptosis and duration of thyroid disease. The area under curve of OA-PSV (95% CI:0.964-1.000, p < 0.001) and OA-EDV (95% CI:0.699-0.905, p < 0.001) helped in differentiating TED orbits from HC, and in predicting the severity of disease. Post decompression, CRA-PSV, CRA-EDV, OA-PSV, and OA-EDV improved, with decrease in CRA-RI and OA-RI in both lipogenic and MO.
CONCLUSIONS
The orbital perfusion is reduced in inactive TED. The changes in OA flow velocities can help in differentiating inactive TED from healthy orbits and progression of TED. Sequential orbital CDI of OA and CRA can serve as an objective tool for case selection and monitoring response to surgical decompression.
Topics: Adult; Female; Humans; Male; Middle Aged; Blood Flow Velocity; Ciliary Arteries; Eye; Graves Ophthalmopathy; Hemodynamics; Ophthalmic Artery; Retinal Artery; Ultrasonography, Doppler, Color
PubMed: 37221361
DOI: 10.1038/s41433-023-02580-2