Clinical hemorheology and microcirculation最新文献

Background: Data on the effect of transcatheter aortic valve implantation (TAVI) on peripheral microcirculation are limited.

Objective: The aim of this study is to evaluate peripheral microvascular tissue saturation (StO2) before and after TAVI in relation to central and peripheral hemodynamics, cardiac and renal function.

Methods: In this single-center prospective study, patients with severe aortic stenosis (sAS) scheduled for TAVI or cardiac catheterization (control) were assessed before and up to five days after the procedure. Cardiac function including cardiac output (CO) was assessed by echocardiography. Brachial (bBP) and central blood pressure (cBP), ankle brachial index (ABI), and parameters of arterial stiffness, including augmentation pressure (AP) and augmentation index adjusted for heart rate (AIx@HR75) were measured to assess hemodynamic changes. StO2 was measured in all extremities using a near-infrared spectroscopy (NIRS) camera. Renal function was measured by creatinine levels.

Results: 26 patients underwent TAVI and 11 patients served as control. Cardiac output was significantly increased, whereas hemodynamic parameters and peripheral StO2 were significantly decreased after TAVI. At follow-up, StO2 returned to baseline values. Changes in StO2 were negatively related to creatinine levels.

Conclusion: Transcatheter aortic valve implantation causes a temporary decrease in microvascular tissue saturation that is associated with renal function.

Objective: The carotid stiffness is an important factor in the pathogenesis of cerebrovascular small vessel disease. Our study aimed to evaluate the relation of the local arterial stiffness of the common carotid artery (CCA) to the hemodynamic forces and blood viscosity in patients with cerebral lacunar infarctions (LI).

Methods: Twenty-two patients with chronic LI and 15 age-matched controls were examined. An ultrasound examination of the CCA intima-media thickness (IMT), the parameters of local CCA stiffness: distensibility (DC) and compliance coefficients (CC), α and β stiffness indices and pulse wave velocity (PWV) was performed. The local hemodynamic forces were calculated: circumferential wall tension (CWT) and wall shear stress (WSS). Whole blood viscosity (WBV) and shear stresses at shear rates of 0.277 s- 1 to 94.5 s- 1 were measured in patients and controls.

Results: Higher values of IMT, a significant decrease of DC and CC and an increase of α and β stiffness indices and PWV in the LI patients compared to the controls were obtained. A parallel significant increase in CWT and a decrease in WSS was found. An increase in WBV and a significant increase in shear stresses were detected. In the LI patients, the increased stiffness indices were associated with an increase in age, cholesterol and WBV at higher shear rates in the left CCA. In the controls, the IMT and stiffness indices correlated significantly with the hemodynamic factors and WBV in both CCAs, while the stiffness indices correlated with the hemodynamic forces in the left CCA.

Conclusion: The results of the present study demonstrate different associations of the local carotid stiffness indices with the hemodynamic forces and WBV in patients with LI and controls.

Aim: First assessment of flow changes in the jugular veins using high resolution ultrasound vector flow.

Material und methods: 15 patients (8 males, 7 females) with an age range of 35 to 82 years (mean age 58.53±12.26 years) were examined by an experienced examiner using high power ultrasound equipment (Resona R9, Mindray) with probe technology (Mindray L9-3U Linear Array transducer, 2.5 to 9.0 MHz). This group was compared with five healthy subjects (mean age 35.4±13.79 years) as a reference. To assess flow changes, the color-coded duplex sonography and the novel vector flow technique were used. The evaluation was performed of vector morphology changes, turbulence, and wall resistance measurements.

Results: There were changes after acute and chronic thrombosis in 9 cases, and venous compression in 7 cases. Turbulence was measurable from 0.01 % to 64.44 %, the average turbulence was 19.73±22.06 %. Wall resistance measurement showed values from 0.01 Pa to 3.14 Pa, depending on the age of the thrombosis or compression. The reference veins showed turbulence of 0.94±1.5 % and a mean wall resistance of 0.05±0.05 Pa. There are statistically significant differences between normal and thrombotic or compressed veins in terms of maximum wall stress (p = 0.006) and mean degree of turbulence (p = 0.012), while the difference in mean wall stress is not statistically significant (p = 0.058).

Conclusion: Despite still existing technical limitations, the combination of V-flow and wall stress measurements in jugular vein changes suggests a high diagnostic potential.

Background: Deep sternal wound infections (DSWI) following cardiothoracic surgery represent a life quality endangering sequelae and may lead to sternal osteomyelitis. Radical debridement followed by Negative Pressure Wound Therapy (NPWT) may achieve infection control, provide angiogenesis, and improve respiratory function. When stable wound conditions have been established a sustainable plastic surgical flap reconstruction should be undertaken.

Objective: This study analyses a method to simplify defect coverage with a single Latissimus Dorsi Myocutaneous Flap (LDMF).

Methods: Preparation of 20 LDMF in ten fresh frozen cadavers was conducted. Surgical steps to increase pedicle length were evaluated. The common surgical preparation of LDMF was compared with additional transection of the Circumflex Scapular Artery (CSA).

Results: Alteration of the surgical preparation of LDMF by sacrificing the CSA may provide highly valuable well-vascularized muscle tissue above the sensitive area of the Xiphisternum. All defects could be completely reconstructed with a single LDMF. The gain in length of flap tissue in the inferior third of the sternum was 3.86±0.9 cm (range 2.2 to 8 cm).

Conclusions: By sacrificing the CSA in harvesting the LDMF a promising gain in length, perfusion and volume may be achieved to cover big sternal defects with a single flap.

The size of body compartments is a determinant of several factors of blood viscosity. Red cell aggregation is proportional to fat mass while hematocrit is proportional to both fat-free mass and abdominal adiposity, but which parts of these body components are involved in this relationship is not known. Segmental bioelectrical impedance analysis (sBIA) provides a possibility to delineate the relationships more precisely between various subdivisions of the body and blood viscosity factors, going farther than preceding studies using non segmental BIA. In this study we investigated in 38 subjects undergoing a standardized breakfast test with mathematical modelling of glucose homeostasis and a segmental bioelectrical impedance analysis (sBIA) the relationships between the various compartments of the body and viscosity factors. Blood and plasma viscosity were measured with the Anton Paar rheometer and analyzed with Quemada's model. The parameters better correlated to hematocrit are fat free mass (r = 0.562) and its two components muscle mass (r = 0.516) and non-muscular fat-free mass (r = 0.452), and also trunk fat mass (r = 0.383) and waist-to hip ratio (r = 0.394). Red cell aggregation measurements were correlated with both truncal and appendicular fat mass (r ranging between 0.603 and 0.728). Weaker correlations of M and M1 are found with waist circumference and hip circumference. This study shows that the correlation between lean mass and hematocrit involves both muscle and non-muscle moieties of lean mass, and that both central and appendicular fat are determinants of red cell aggregation.

Background: Type 2 diabetes accelerates the loss of muscle mass and strength. Sarcopenia is also one of the chronic complications of diabetes.

Objective: To investigate the clinical value of B mode ultrasound (BMUS) and shear wave elastography (SWE) for predicting type 2 diabetic sarcopenia.

Methods: We recorded Skeletal Muscle Mass Index (ASMI), grip strength, muscle thickness (MT), pinna angle (PA), fascicle length (FL), and the difference of Young's modulus in the relaxed states and tense states (ΔSWE). The correlations between clinical indicators and ultrasound characteristics were compared. A diagnostic model of sarcopenia was developed to assess the independent correlates and evaluate the diagnostic efficacy of sarcopenia.

Results: ASMI was significantly and positively correlated with MT and ΔSWE (r = 0.826, 0.765, P < 0.01), and grip strength was significantly and positively correlated with MT and ΔSWE (r = 0.797, 0.818, P < 0.01). MT was the most significant predictor of sarcopenia (OR = 4.576, P < 0.001), and the cut-off value of MT was 11.4 mm (AUC: 0.952).

Conclusion: BMUS and SWE can quantitatively assess muscle mass and strength, and are effective methods to predict the occurrence of sarcopenia in elderly patients with type 2 diabetes.

 Recently diagnostic field in medicine was enriched by advances in ultrasonography (US) technology, which led to establishment of novel modalities, one of which is micro-ultrasound. Results demonstrated by early studies have been promising, simultaneously rising a question if those new modalities could become an alternative in diagnosis of prostatic carcinoma (PCa). To answer this question, several studies have been conducted where micro-ultrasound have been compared to standard diagnostic tools, such as conventional TRUS or mpMRI. Nevertheless, new technology presents with some limitations, which include inconsistent results, necessity for specialized equipment, need of training for investigators to understand the findings, and external validation. In this publication, we have identified studies that provided evaluation of the accuracy and efficiency of the micro-ultrasound technology. Additionally, analysis of the results provided a better understanding of the novel imaging tool when compared standard modalities in diagnosis of PCa. Increasing number of studies demonstrated that micro-ultrasound carries high detection rate of PCa and clinically significant prostatic cancer (csPCa), suggesting a similar performance to mpMRI and even showing superiority over conventional TRUS. Recent studies have also showed that micro-ultrasound takes active role in improving the detection of csPCa and guidance for prostate biopsy (PBx) as well as further treatment. Moreover, certain practical aspects such as lower costs, decreased waiting time, real-time imaging and application of the imaging tool for patients that are not suitable for mpMRI (contrast allergy, prosthetics etc.) are significant advantages. Analysis of the results still does not provide clear answer whether micro-ultrasound outperforms mpMRI. Further studies are necessary in order to completely understand the potential of this new technology.

 Secretory carcinoma of the breast (SCB) is a rare and specific type of breast cancer. Owing to its rarity, the number of SCB reports available is limited, with most of them focusing on clinical and pathological characteristics but no reports on its multimodal ultrasound (US) features. Thus, we present a rare case of SCB, retrospectively analyzing manifestations of US and contrast-enhanced US, as well as its pathological basis, aiming to enhance the understanding of US image features of SCB and provide more valuable information for clinical diagnosis. Moreover, the treatment strategy adopted for this patient may serve as a template for future management of SCB.

Objective: To investigate the diagnostic value of CEUS in atypical-enhanced PTC.

Methods: The clinical data, qualitative and quantitative parameters of CEUS in 177 Iso/hyper-enhanced thyroid nodules with definite pathological results were retrospectively analyzed in the Lanzhou University Second Hospital from June 2019 to January 2021. And the clinical value of CEUS in the diagnosis of atypical-enhanced PTC was assessed using univariate and multivariate analysis.

Results: Among the 177 thyroid nodules, 59 were benign and 118 were PTC. There were significant differences in age, enhancement border, ring enhancement, speed of wash in, speed of wash out, enhancement pattern, capsule interruption, time to peak, time to wash out, RT, TPH, and TTP (P < 0.05). Multivariate analysis showed unclear enhancement border and concentric enhancement were independent risk factors for the diagnosis of atypical-enhanced PTC by CEUS. The sensitivity, specificity, PPV, NPV, and accuracy of the model in diagnosing atypical-enhanced PTC were 88.1%, 71.2%, 86.0%, 75.0%, and 82.5%, respectively. The area under the curve (AUC) of the receiver operating characteristic (ROC) curve was 0.910.

Conclusion: The diagnosis of atypical-enhanced PTC can be better performed by enhancement characteristics and time intensity curve (TIC) of CEUS, which have a good clinical application value.

Background: Despite the well-recognized effectiveness of Ruscus aculetus extract combined or not with ascorbic acid (AA) and hesperidine methyl chalcone (HMC) on ischemia reperfusion (I/R) injury protection, little is known about the contribution of each constituent for this effect.

Objective: To investigate the effects of AA and HMC combined or not with Ruscus extract on increased macromolecular permeability and leukocyte-endothelium interaction induced by I/R injury.

Methods: Hamsters were treated daily during two weeks with filtered water (placebo), AA (33, 100 and 300 mg/kg/day) and HMC (50, 150 and 450 mg/kg/day) combined or not with Ruscus extract (50, 150 and 450 mg/kg/day). On the day of experiment, the cheek pouch microcirculation underwent 30 min of ischemia, and the number of rolling and adherent leukocytes and leaky sites were evaluated before ischemia and during 45 min of reperfusion.

Results: Ruscus extract combined with AA and HMC (Ruscus extract mixture) significantly prevented post-ischemic increase in leukocyte rolling and adhesion and macromolecular permeability compared to placebo and these effects were more prominent than AA and HMC alone on leukocyte adhesion and macromolecular leakage.

Conclusion: Ruscus extract mixture were more effective than its isolated constituents in protect the hamster cheek pouch microcirculation against I/R injury.