Quantitative assessment of carotid ultrasound diameter measurements in the operating room: a comparable analysis of long-axis versus rotated and tilted orientation.

Objective. Carotid ultrasound (US) has been studied as a non-invasive alternative for hemodynamic monitoring. A long-axis (LA) view is traditionally employed but is difficult to maintain and operator experience may impact the diameter estimates, making it unsuitable for monitoring. Preliminary results show that a new, i.e. rotated and tilted (RT) view is more robust to motion and less operator-dependent. This study aimed to quantitatively assess common carotid diameter estimates obtained in a clinical setting from an RT view and compare those to corresponding estimates obtained using other views.Approach. Carotid US measurements were performed in 30 adult cardiac-surgery patients (26 males, 4 females) with short-axis (SA), LA, and RT probe orientations, the first being used as a reference for measuring the true vessel diameter. Per 30 s acquisition, the median and spread in diameter values were computed, the latter representing a measure of robustness, and were statistically compared between views.Main results. The median (IQR) over all the patients of the median diameter per 30 s acquisition was 7.15 (1.15) mm for the SA view, 7.03 (1.51) mm for the LA view, and 6.99 (1.72) mm for the RT view. The median spread in diameter values was 0.18 mm for the SA view, 0.16 mm for the LA view, and 0.18 mm for the RT view. There were no statistically significant differences between views in the median diameter values (p= 0.088) or spread (p= 0.122).Significance. The RT view results in comparable and equally robust median carotid diameter values compared to the reference. These findings open the path for future studies investigating the use of the RT view in new applications, such as in wearable ultrasound devices.

Biplanar versus conventional two-dimensional ultrasound guidance for radial artery catheterisation.

Background: Ultrasound guidance increases first-pass success rates and decreases the number of cannulation attempts and complications during radial artery catheterisation but it is debatable whether short-, long-, or oblique-axis imaging is superior for obtaining access. Three-dimensional (3D) biplanar ultrasound combines both short- and long-axis views with their respective benefits. This study aimed to determine whether biplanar imaging would improve the accuracy of radial artery catheterisation compared with conventional 2D imaging. Methods: This before-and-after trial included adult patients who required radial artery catheterisation for elective cardiothoracic surgery. The participating anaesthesiologists were experienced in 2D and biplanar ultrasound-guided vascular access. The primary endpoint was successful catheterisation in one skin break without withdrawals. Secondary endpoints were the numbers of punctures and withdrawals, scanning and procedure times, needle visibility, perceived mental effort of the operator, and posterior wall puncture or other mechanical complications. Results: From November 2021 until April 2022, 158 patients were included and analysed (2D=75, biplanar=83), with two failures to catheterise in each group. First-pass success without needle redirections was 58.7% in the 2D group and 60.2% in the biplanar group (difference=1.6%; 95% confidence interval [CI], -14.0%-17.1%; P=0.84), and first-pass success within one skin break was 77.3% in the 2D group vs 81.9% in the biplanar group (difference=4.6%; 95% CI, 8.1%-17.3%; P=0.473). None of the secondary endpoints differed significantly. Conclusions: Biplanar ultrasound guidance did not improve success rates nor other performance measures of radial artery catheterisation. The additional visual information acquired with biplanar imaging did not offer any benefit. Clinical trial registration: N9687 (Dutch Trial Register).

Applications of rotational thromboelastometry in heparin monitoring in critical COVID-19 disease: Observations in the Maastricht Intensive Care COVID cohort.

Background: Critically ill COVID-19 patients are at risk for venous thromboembolism (VTE). Therefore, they receive thromboprophylaxis and, when appropriate, therapeutic unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH). To monitor heparins in COVID-19 disease, whole-blood rotational thromboelastometry (ROTEM) may be a promising alternative to the aPTT and anti-Xa assays. Objective: To evaluate the ROTEM INTEM/HEPTEM ratios in mechanically ventilated COVID-19 patients treated with UFH and therapeutic LMWH. Material and methods: A subcohort of mechanically ventilated COVID-19 patients of the prospective Maastricht Intensive Care Covid (MaastrICCht) cohort was studied. Anti-Xa, aPTT, and ROTEM measurements following treatment with UFH or therapeutic dose of LMWH (nadroparin) were evaluated using uni- and multivariable linear regression analysis and receiver operating characteristics. Results: A total of 98 patients were included, of which 82 were treated with UFH and 16 with therapeutic LMWH. ROTEM-measured INTEM/HEPTEM CT ratio was higher in patients using UFH (1.4 [1.3-1.4]) compared to patients treated with LMWH (1.0 [1.0-1.1], p < 0.001). Both the aPTT and anti-Xa were associated with the CT ratio. However, the ß-regression coefficient (95%CI) was significantly higher in patients on UFH (0.31 (0.001-0.62)) compared to therapeutic LMWH (0.09 (0.05-0.13)) for comparison with the anti-Xa assay. Furthermore, ROC analysis demonstrated an area under the curve for detecting UFH of 0.936(0.849-1.00), 0.851(0.702-1.000), and 0.645(0.465-0.826) for the CT ratio, aPTT, and anti-Xa, respectively. Conclusion: The ROTEM INTEM/HEPTEM CT ratio appears a promising tool to guide anticoagulant therapy in ICU patients with COVID-19 disease, but associations with clinical endpoints are currently lacking.

Proinflammatory T cells and IL-17 stimulate osteoblast differentiation.

The local immune response is important to consider when the aim is to improve bone regeneration. Recently T lymphocytes and their associated cytokines have been identified as regulators in fracture callus formation, but it is not known whether T cells affect bone progenitor cells directly. The goal of this in vitro study was to investigate the role of different T cell subsets and their secreted factors on the osteogenic differentiation of human mesenchymal stem cells (MSCs). Significant increases in the alkaline phosphatase activity and the subsequent matrix mineralization by MSCs were found after their exposure to activated T cells or activated T cell-derived conditioned medium. Blocking IFN-γ in the conditioned medium abolished its pro-osteogenic effect, while blocking TGF-ß further enhanced osteogenesis. The relative contribution of an anti- or proinflammatory T cell phenotype in MSC osteogenic differentiation was studied next. Enrichment of the fraction of anti-inflammatory regulatory T cells had no beneficial osteogenic effect. In contrast, soluble factors derived from enriched T helper 17 cells upregulated the expression of osteogenic markers by MSCs. IL-17A, and IL-17F, their main proinflammatory cytokines, similarly exhibited strong osteogenic effects when exposed directly to MSCs. IL-17A in particular showed a synergistic action together with bone morphogenetic protein 2. These results indicate that individual T cell subsets, following their activation, affect osteoblast maturation in a different manner through the production of soluble factors. From all T cells, the proinflammatory T cells, including the T helper 17 cells, are most stimulatory for osteogenesis.

Carotid artery stenting and cardiac surgery in symptomatic patients.

OBJECTIVES: The purpose of this study was to evaluate the feasibility and safety of the combined outcome of carotid artery stenting (CAS) and coronary artery bypass graft (CABG) surgery in neurologically symptomatic patients. BACKGROUND: The risk of perioperative stroke in patients undergoing CABG who report a prior history of transient ischemic attack or stroke has been associated with a 4-fold increased risk as compared to the risk for neurologically asymptomatic patients. It seems appropriate to offer prophylactic carotid endarterectomy to neurologically symptomatic patients who have significant carotid artery disease and are scheduled for CABG. The CAS-CABG outcome for symptomatic patients remains underreported, notwithstanding randomized data supporting CAS for high-risk patients. METHODS: In a prospective, single-center study, the periprocedural and long-term outcomes of 57 consecutive patients who underwent CAS before cardiac surgery were analyzed. RESULTS: The procedural success rate of CAS was 98%. The combined death, stroke, and myocardial infarction rate was 12.3%. The death and major stroke rate from time of CAS to 30 days after cardiac surgery was 3.5%. The myocardial infarction rate from time of CAS to 30 days after cardiac surgery was 1.5%. CONCLUSIONS: This is the first single-center study reporting the combined outcome of CAS-CABG in symptomatic patients. The periprocedural complication rate and long-term results of the CAS-CABG strategy in this high-risk population support the reliability of this approach. In such a high-risk population, this strategy might offer a valuable alternative to the combined surgical approach; however, a large randomized trial is clearly warranted.

CT measurement of changes in cerebral perfusion in patients with asymptomatic carotid artery stenosis undergoing carotid stenting prior to cardiac surgery: "proof of principle".

AIMS: To identify asymptomatic patients with impaired cerebral perfusion using CT perfusion (CTP) technique during staged carotid stenting (CAS) and cardiac surgery. METHODS AND RESULTS: This is a prospective, non-randomised study in 16 neurologically asymptomatic patients designed to analyse cerebral perfusion using CTP before and after CAS. Mean transit time (MTT) was significant lower and cerebral blood flow (CBF) was significantly higher in the non-target hemisphere compared to the target hemisphere before treatment (4.64 ± 1.08 s vs. 5.67 ± 1.29 and 57.37 ± 24.90 s vs. 48.19 ± 13.02, respectively). Mean dMTT (absolute difference in MTT values between treated and untreated hemisphere) decreased from 0.92 ± 1.08 s before to 0.04 ± 0.30 s after carotid revascularisation (p<0.05) and mean relative CBF (ratios of the treated to the untreated hemisphere) increased from 0.92 ± 0.12 to 1.04 ± 0.12 after revascularisation (p<0.05). Subgroup analysis based on pre-treatment dMTT showed significant changes in 50% of the patients with larger dMTT. There was one transient ischaemic attack reported 30 days after combined procedure. CONCLUSIONS: A significant improvement of cerebral perfusion after carotid stenting is shown in about 50% of the asymptomatic patients in this study. This suggests the potential presence of a compromised cerebral circulation in asymptomatic patients with severe carotid artery disease scheduled for cardiac surgery.