超声引导下腹横肌平面阻滞对于妇科腹腔镜手术患者预防性镇痛的效果

目的评价超声引导下腹横肌平面阻滞(TAPB)对于妇科腹腔镜手术患者预防性镇痛的效果。方法选取拟在全麻下行妇科腹腔镜手术患者60例,既往无其他特殊病史,美国麻醉医师协会(ASA)分级Ⅰ或Ⅱ级,年龄30~50岁,体重50~65 kg。采用随机数字表法,将其分为3组(n=20):对照组(Ⅰ组)、术前TAPB组(Ⅱ组)和术后TAPB组(Ⅲ组)。Ⅰ组不实施神经阻滞,Ⅱ组和Ⅲ组分别于麻醉诱导前或手术结束后行超声引导下双侧TAPB术。术后3组患者均采用1μg/ml舒芬太尼静脉自控镇痛(PCIA),背景输注速率2 ml/h,患者自控镇痛(PCA)剂量2 ml,锁定时间15 min,持续至术后第2天,维持疼痛视觉模拟(VAS)评分≤3分,若VAS评分3分时,静脉注射氟比洛芬酯50 mg行镇痛补救。记录术后24 h内舒芬太尼单位时间内用量、镇痛补救情况和不良反应的发生情况,计算舒芬太尼节俭程度。结果与Ⅰ组比较,Ⅱ组和Ⅲ组术后24 h内舒芬太尼单位时间内用量、镇痛补救率和恶心呕吐的发生率降低(P0.05);与Ⅲ组比较,Ⅱ组术后24 h内舒芬太尼单位时间内用量、镇痛补救率及恶心呕吐的发生率降低(P0.05)。Ⅱ组较Ⅰ组舒芬太尼用量节俭35.0%,较Ⅲ组舒芬太尼用量节俭16.0%。结论超声引导下TAPB能为妇科腹腔镜手术患者提供良好的术后镇痛,术前行神经阻滞效果优于术后。     

Additional Prognostic Value of 2D Right Ventricular Speckle-Tracking Strain for Prediction of Survival in Heart Failure and Reduced Ejection Fraction: A Comparative Study With Cardiac Magnetic Resonance

ObjectivesThis study sought to compare the prognostic value of 2-dimensional (2D) right ventricular (RV) speckle tracking (STE) against cardiac magnetic resonance (CMR) RV ejection fraction (EF) and feature tracking (FT) and conventional echocardiographic parameters on overall and cardiovascular (CV) survival in patients with heart failure with reduced EF (HFrEF).BackgroundPrior works showed that RV systolic function predicts prognosis in HFrEF. 2D RVSTE had recently been proposed as new echocardiographic method to evaluate RV dysfunction.MethodsA total of 266 patients with HFrEF (mean LVEF 23 ± 7%, 60 ± 14 years of age; 29% women) underwent RV function assessment using CMR and 2D echocardiography and were followed for a primary endpoint of overall death and secondary endpoint of CV death.ResultsAverage CMR-RVEF was 42 ± 15%, average STE RV global longitudinal strain (STE-RVGLS) was −18.0 ± 4.9%, and average CMR-FT-RVGLS was −11.8 ± 4.3%. After a median follow-up of 4.7 years, 102 patients died, 84 of a CV cause. RVEF, FT-RVGLS, tricuspid annulus plane systolic excursion (TAPSE), fractional area change (FAC), and STE-RVGLS were significant univariate predictors of overall and cardiac death. In multivariate Cox regression, age, ischemic etiology, diabetes, New York Heart Association functional class III to IV, and beta-blocker treatment were independent clinical predictors of overall mortality. CMR-RVEF (chi-square to enter = 3.9; p < 0.05), FT-RVGLS (chi-square to enter 3.7; p = 0.05), FAC (chi-square to enter 6.2; p = 0.02), and TAPSE (chi-square to enter = 4.1; p = 0.04) provided additional prognostic value over these baseline parameters, but the additional predictive value of STE-RVGLS (chi-square to enter = 10.8; p < 0.001) was significantly (p < 0.05) higher than the other tests. Additional hazard ratio to predict overall mortality was 2.5 (95% confidence interval [CI]: 1.6 to 3.9) for STE-RVGLS <−19%, 2.15 (95% CI: 1.34 to 3.43) for TAPSE >15 mm, 1.6 (95% CI: 1.02 to 2.49) for FAC >39%, 1.93 (95% CI: 1.25 to 2.99) for RVEF >41%, and 1.87 (95% CI: 1.10 to 3.19) for CMR-FT-RVGLS <−15%.Conclusions2D RVGLS provides strong additional prognostic value to predict overall and CV mortality in HFrEF, with higher predictive value than CMR-RVEF, CMR-FT-RVGLS, TAPSE, or FAC. This supports use of STE-RVGLS to identify higher-risk HFrEF patients.     

Clinical Importance of Left Atrial Infiltration in Cardiac Transthyretin Amyloidosis

ObjectivesThe aim of this study was to characterize left atrial (LA) pathology in explanted hearts with transthyretin amyloid cardiomyopathy (ATTR-CM); LA mechanics using echocardiographic speckle-tracking in a large cohort of patients with ATTR-CM; and to study the association with mortality.BackgroundThe clinical significance of LA involvement in ATTR-CM is of great clinical interest.MethodsCongo red staining and immunohistochemistry was performed to assess the presence, type, and extent of amyloid and associated changes in 5 explanted ATTR-CM atria. Echo speckle tracking was used to assess LA reservoir, conduit, contractile function, and stiffness in 906 patients with ATTR-CM (551 wild-type (wt)-ATTR-CM; 93 T60A-ATTR-CM; 241 V122I-ATTR-CM; 21 other).ResultsThere was extensive ATTR amyloid infiltration in the 5 atria, with loss of normal architecture, vessels remodeling, capillary disruption, and subendocardial fibrosis. Echo speckle tracking in 906 patients with ATTR-CM demonstrated increased atrial stiffness (median [25th-75th quartile] 1.83 [1.15-2.92]) that remained independently associated with prognosis after adjusting for known predictors (lnLA stiff: HR: 1.23; 95% CI: 1.03-1.49; P = 0.029). There was substantial impairment of the 3 phasic functional atrial components (reservoir 8.86% [5.94%-12.97%]; conduit 6.5% [4.53%-9.28%]; contraction function 4.0% [2.29%-6.56%]). Atrial contraction was absent in 22.1% of patients whose electrocardiograms showed sinus rhythm (SR) “atrial electromechanical dissociation” (AEMD). AEMD was associated with poorer prognosis compared with patients with SR and effective mechanical contraction (P = 0.0018). AEMD conferred a similar prognosis to patients in atrial fibrillation.ConclusionsThe phenotype of ATTR-CM includes significant infiltration of the atrial walls, with progressive loss of atrial function and increased stiffness, which is a strong independent predictor of mortality. AEMD emerged as a distinctive phenotype identifying patients in SR with poor prognosis.     

Comparison of biplane and single plane left ventricular volumes in atrial septal defect

The close agreement between biplane (BP) and single-plane (SP) angiographic estimates of left ventricular (LV) volumes results from the similarity of the minor axes measured in the right anterior oblique (RAO) and left anterior oblique (LAO) views. Disease states that alter LV geometry may change the length of one minor axis more than the other, producing a discrepancy between BP and SP volumes. To examine this hyposthesis, angiographically derived volumes in 21 patients with atrial septal defects (ASD) in which the LV appears to be compressed and flattened by an enlarged right ventricle, were compared to 100 normal control patients. In the control patients, the median SP estimate of end-diastolic volume (EDV) was 7.6% larger than the BP determination, whereas in patients with ASD, the median SP EDV estimate was 16.7% larger than the BP EDV (P<0.0001). The SP end-systolic volume (ESV) underestimated the BP value by 3.4% in controls but overestimated the BP ESV in patients with ASD by 4.3% (P<0.02). The overestimate of the SP EDV and SP ESV when compared to the BP volumes may be due to changes in either the minor axes or the appearance of the longest major axis in the LAO view. The longest major axis was found in the RAO view in 99% (99/100) of normals and 95% (20/21) of ASD patients (P?NS). The median ratio of RAO to LAO end-diastolic minor axes, however, was 1.07 in the normals and 1.17 for ASD patients. The median ratio of end-systolic minor axes was 0.97 for controls and 1.04 for ASD patients. Compression of the LV in patients with ASD shortens the LAO minor axis, resulting in a significantly greater SP overestimation of LV volume than occurs in normals. The degree of SP volume overestimate was not predicted by the magnitude of the left-to-right shunt or pulmonary pressure. This source of error affects all SP methods for determining left ventricular volume, including radionuclide techniques using static images.     

Large-scale characterization of the microvascular geometry in development and disease by tissue clearing and quantitative ultramicroscopy

Three-dimensional assessment of optically cleared, entire organs and organisms has recently become possible by tissue clearing and selective plane illumination microscopy (“ultramicroscopy”). Resulting datasets can be highly complex, encompass over a thousand images with millions of objects and data of several gigabytes per acquisition. This constitutes a major challenge for quantitative analysis. We have developed post-processing tools to quantify millions of microvessels and their distribution in three-dimensional datasets from ultramicroscopy and demonstrate the capabilities of our pipeline within entire mouse brains and embryos. Using our developed acquisition, segmentation, and analysis platform, we quantify physiological vascular networks in development and the healthy brain. We compare various geometric vessel parameters (e.g. vessel density, radius, tortuosity) in the embryonic spinal cord and brain as well as in different brain regions (basal ganglia, corpus callosum, cortex). White matter tract structures (corpus callosum, spinal cord) showed lower microvascular branch densities and longer vessel branch length compared to grey matter (cortex, basal ganglia). Furthermore, we assess tumor neoangiogenesis in a mouse glioma model to compare tumor core and tumor border. The developed methodology allows rapid quantification of three-dimensional datasets by semi-automated segmentation of fluorescently labeled objects with conventional computer hardware. Our approach can aid preclinical investigations and paves the way towards “quantitative ultramicroscopy”.     

Association between ankle angle at initial contact and biomechanical ACL injury risk factors in male during self-selected single-leg landing

BackgroundIncreasing the ankle plantar-flexion angle at initial contact (IC) during landing reduces the impact features associated with landing, such as the vertical ground reaction force and loading rate, potentially affecting the risk of anterior cruciate ligament (ACL) injury. However, the relationships between the ankle plantar-flexion angle at IC and the previously identified biomechanical factors related to noncontact ACL injury have not been studied.Research questionThus, the purpose of this study was to determine whether significant relationships exist between the ankle plantar-flexion angle at IC and the biomechanical factors related to noncontact ACL injury.MethodsThe peak anterior tibial shear force, peak external knee valgus moment, peak knee valgus angle, and combined peak external knee valgus plus tibial internal rotation moments were measured in 26 individuals while performing self-selected, single-leg landing. Pearson correlation analyses were performed to assess the relationships between the ankle plantar-flexion angle at IC and the biomechanical factors mentioned above.ResultsThe greater ankle plantar-flexion angle at IC was related to smaller the peak knee valgus moment (r = −0.5, p = 0.009) and the combined peak knee valgus plus internal rotation moments (r = −0.58, p = 0.001).SignificanceThese results suggest that large ankle plantar-flexion angle at IC might be associated with lesser loading of the knee frontal plane and altering the self-selective ankle angle may result in biomechanical changes associated with ACL injury risk.     

Temperature prediction in high speed bone grinding using motor PWM signal

This research explores the feasibility of using motor electrical feedback to estimate temperature rise during a surgical bone grinding procedure. High-speed bone grinding is often used during skull base neurosurgery to remove cranial bone and approach skull base tumors through the nasal corridor. Grinding-induced heat could propagate and potentially injure surrounding nerves and arteries, and therefore, predicting the temperature in the grinding region would benefit neurosurgeons during the operation. High-speed electric motors are controlled by pulse-width-modulation (PWM) to alter the current input and thus maintain the rotational speed. Assuming full mechanical to thermal power conversion in the grinding process, PWM can be used as feedback for heat generation and temperature prediction. In this study, the conversion model was established from experiments under a variety of grinding conditions and an inverse heat transfer method to determine heat flux. Given a constant rotational speed, the heat conversion was represented by a linear function, and could predict temperature from the experimental data with less than 20% errors. Such results support the advance of this technology for practical application.     

矢状切面在妊娠早期超声筛查胎儿腭裂中的价值

目的探讨矢状切面在妊娠早期超声筛查胎儿腭裂中的价值。 方法回顾性选择2018年1月至2019年12月广东省妇幼保健院的31例妊娠早期腭裂的胎儿,分析头颈部超声检查矢状切面的异常征象,总结不同类型腭裂在矢状切面的超声表现以及其他结构异常情况。 结果（1）超声声像图表现：28例出现上颌骨间隙（90.3%,28/31）,其中14例为单侧腭裂,5例为双侧腭裂,9例为正中腭裂;27例表现为缺失“重叠线征”（87.1%,27/31）,其中正中腭裂5例,单侧腭裂15例,双侧腭裂6例,单纯腭裂1例;6例颌骨前突（19.4%,6/31）,均为双侧唇腭裂。（2）合并其他结构异常情况：妊娠早期及妊娠中期诊断腭裂病例中,合并胎儿结构异常分别占75.0%（15/20）、45.5%（5/11）,颈项透明层增厚分别占60.0%（12/20）、36.4%（4/11）。 结论矢状切面上颌间隙和缺失“重叠线征”是妊娠早期筛查胎儿腭裂的重要线索,颌骨前突是双侧腭裂的特征性超声表现。