Clinical hemorheology and microcirculation最新文献

ObjectivesTo investigate the role of high-frequency ultrasound in detection of occult focal liver lesions (FLLs).MethodsIn this retrospective study from April 2016 to March 2019, eighty-five patients with indistinctive FLLs were included. High-frequency and low-frequency B-mode ultrasound (BMUS) and contrast-enhanced ultrasound (CEUS) were performed for each lesion. The detection rates of two methods and the ultrasound performance of co-detected lesions were compared. Subgroup analysis was performed according to different liver backgrounds.ResultsFor 85 FLLs with mean diameter of 11.80 ± 4.66 mm and mean depth of 20.91 ± 6.89 mm, high-frequency BMUS detected 77 (90.6%) lesions, significantly more than low-frequency BMUS (36, 42.4%, p < 0.001). Among the lesions co-detected by low-frequency and high-frequency ultrasound, the lesions at high-frequency mainly showed heterogeneous echogenicity (p < 0.001), regular morphology (p < 0.001), well-defined boundary (p < 0.001) and inhomogeneous enhancement (p < 0.001) in arterial phase. Even in the presence of cirrhosis or fatty liver, high-frequency ultrasound still performed excellently.ConclusionHigh-frequency ultrasound improves the detection of small and superficially located FLLs.

Objectives: To assess multimodality ultrasound features of renal cell carcinomas (RCCs) with different tumor sizes, especially in RCCs ≤ 3 cm in diameter. Patients & Methods: Patients with surgery resection and histopathologically confirmed RCCs were included. All patients underwent multimodality ultrasound examinations one week before surgery. Results: From July 2023 to January 2024, a total of 81 RCCs were finally enrolled, including Group 1 (≤ 3 cm, n = 41) and Group 2 (> 3 cm, n = 40). Hypervascular blood supply could be observed more commonly in RCCs > 3 cm than in RCCs ≤ 3 cm (P = 0.039) by MVI. The median SWV values of RCCs > 3 cm were higher than those in the RCCs ≤ 3 cm (P = 0.038). During arterial phase of CEUS, hyper-enhancement could be observed more often in RCCs > 3 cm (P = 0.246). However, 58.5% (24 / 41) of small RCCs ≤ 3 cm showed relatively late wash out after 60 s (P = 0.005). Conclusions: While comparing to bigger ones, RCCs ≤ 3 cm showed relatively less blood supply in the CDFI and MVI techniques, softer texture, hyperperfusion and later wash out after 60 s on CEUS.

Background: In lower extremity free flap reconstructions, the fragile initial flap perfusion must adapt to orthostatic stress during mobilization, slowing rehabilitation. However, active measures to accelerate this flap training are lacking. Remote Ischemic Conditioning (RIC) has been shown to improve microcirculation, but previous findings are limited to immobilized patients and do not consider the blood pressure-lowering potential of RIC, which could counteract orthostatic regulation.

Objective: To evaluate the effect of RIC on cutaneous perfusion and central hemodynamics during orthostatic stress.

Methods: This before-and-after study included 20 healthy volunteers mobilized on a tilt table. One cycle without conditioning was followed by an RIC-cycle 24 h later. Cutaneous microcirculation was assessed using laser Doppler flowmetry and remission spectroscopy at the anterolateral thigh. Hemodynamic parameters were evaluated using noninvasive continuous finger blood pressure measurements.

Results: RIC resulted in a less pronounced decline in blood flow and oxygen saturation levels below baseline during orthostatic stress (p < 0.003) and a greater increase above baseline during recovery (p < 0.001). Furthermore, post-conditional blood pressure increased more above baseline during orthostastic stress (p < 0.02) and recovery (p < 0.007).

Conclusions: RIC may improve the orthostatic competence of cutaneous microcirculation and central hemodynamics, suggesting its potential to support flap training and earlier patient mobilization.

BackgroundLaparoscopic surgery is widely used in the field of clinical surgery due to its minimal trauma, minimal bleeding, short hospital stay, and fast postoperative recovery. There were several studies found that elderly patients undergoing laparoscopic surgery are more prone to coagulation disorders, increased blood viscosity, and the influence of CO₂ pneumoperitoneum, which can easily lead to changes in blood rheology There are no studies have investigated the effects on blood rheology of general anesthesia combined with epidural block on hemorheology in elderly patients undergoing laparoscopic radical resection of rectal cancer. This trial investigated to explore the effect of general anesthesia combined with epidural block on blood rheology in elderly patients undergoing laparoscopic radical resection of rectal cancer, providing experimental basis for clinical anesthesia to regulate blood rheology characteristics and prevent hyperviscosity and its complications.MethodsA total of 60 patients undergoing laparoscopic radical resection of colorectal cancer, aged 60-75 years, with American Society of Anesthesiologists physical status III, were enrolled in this study. All the subjects were randomly divided into general anesthesia group (group G, n = 30) and general anesthesia in combination with epidural block group (group G + E, n = 30) according to a random number table. Patients in the group G received the general anesthesia alone while those in the group G + E were given the combined epidural block based on anesthetic method of group G. The arterial blood gas indexes (pH, PaCO₂ and HCO₃^-) and hemodynamic indexes(Hŋ_b, Lŋ_b,η_p, EAI, Hct and ESR) were measured at four time points: before induction of general anesthesia (T₀), 5 min before establishment of pneumoperitoneum (T₁), 30 min after establishment of pneumoperitoneum (T₂) and 30 min after elimination of pneumoperitoneum (T₃).ResultsThere was no significant statistical difference (p > 0.05) in pH, PaCO₂, and HCO₃^- between the two groups at T₁, T₂, and T₃. At T₀, there was no significant difference (p > 0.05) in Hŋ_b, Lŋ_b, η_p, Erythrocyte Aggregation Index (EAI), Hct, and Erythrocyte Sedimentation Rate (ESR) between the two groups. However, these indices were significantly lower in group G + E than in group G (p < 0.05) at T₁, T₂, and T₃.ConclusionCombining general anesthesia with epidural block can effectively reduce the hemorheological indexes of patients and improve the hemorheological state in elderly patients with malignant tumors undergoing laparoscopic surgery.

Objective: To evaluate the contribution of modern ultrasound imaging tools such as PDI or MVI in improving detection rate, anatomical visualization, and spectral analysis of the hepatic artery.

Methods: The retrospective single-center study analyzed 40 patients undergoing regular ultrasound control in pre-existing vascular diseases of the liver and after liver transplantation or ablative interventions with furthermore limited examination conditions due to the patient's physique or irregular vascular status after medical treatment such as referred to above. To deal with these conditions, PDI as well as MVI were performed in addition to the standardized B-mode and CCDS. Image quality interpretation was obtained retrospectively by two advanced physicians, evaluating detection rate, anatomical visualization of the vessel itself and artefact-free spectral analysis of the hepatic artery.

Results: All forty patients (28 men, 13 women, age 23-84 years, mean 60 ± 15 years, median 61 years) showed limited examination conditions and underwent analysis of the resistive index (RI) of the hepatic artery (0.56-0.77, mean 0.67 ± 0.06, median 0.67) by using CCDS, as well as PDI and MVI. The reading addressing the image quality resulted in an average value of 2.74 (median 3.00) ± 0.82 for CCDS in the standard device versus an average value of 3.70 ± 0.83 (median 4.00) in the competing device by combining PDI and MVI scores and when addressed separately 3.56 ± 1.02 (median 4.00) for PDI versus 3.58 ± 1.02 (4.00) for MVI. Overall image quality of the competing device combining PDI and MVI was significantly superior to the standard device only using CCDS for both readers in the detection and evaluation of the hepatic artery (p < 0.01) by providing a strong inter-reader reliability for each evaluation.

Conclusion: Combination of PDI and MVI can improve detection and visualization of the hepatic artery and its anatomy in compromised examination settings, as well as artefact-free spectral analysis detecting hemodynamic changes.

During the past few years, there have been a number of new technical developments in the field of high-performance ultrasound diagnostics, which should help us to better assess dynamic vascular changes with ultrasound. BMUS enables us to get important anatomical variants with regard to the portal venous vessels and the hepatic veins. With color-coded duplex sonography (CCDS), and power Doppler (PD), examiners can carry out a comprehensive hemodynamic assessment of the portal venous. However, low flow settings in the vein have always been a particular challenge for CCDS, since the examiner requires special experience and artefacts often occur. In this review article, we reviewed the technical basics and diagnostic possibilities of new digital vascular ultrasound methods, 3D flow methods and contrast enhanced ultrasound (CEUS) in the assessment of portal venous flow changes.

Physical activity combined with low temperatures can improve physical fitness, the efficiency of many organ systems, and mental well-being. The study investigated the effects of single sessions of various forms of physical activity (running, walking, lying down) conducted in a thermal climate chamber at a temperature of -5°C on blood rheological properties in young men. The participants (21 men aged 22 years), when performing the activities, were fasting and hydrated with 500 ml of water. Erythrocyte deformability increased at a shear stress of 4.24 Pa in the walking group and in the jogging group between the measurements before and after the activity. An increase in erythrocyte deformability was also recorded at a shear stress of 8.23 Pa, 15.95 Pa, 30.94 Pa, and 60.00 Pa after running, walking, and lying down compared with the blood indicators measured before these activities. Statistically significant changes were reported for aggregation index in the jogging group after the activity. The increase in erythrocyte deformability at higher shear stress levels may constitute a mechanism to facilitate blood flow in men exposed to a temperature of -5°C. The study revealed specific differences that can be used to combine cold therapy with physical exercise.