Endothelial Dysfunction Criteria in Critically Ill Children: The PODIUM Consensus Conference

OBJECTIVES To review, analyze, and synthesize the literature on endothelial dysfunction in critically ill children with multiple organ dysfunction syndrome and to develop a consensus biomarker-based definition and diagnostic criteria. DATA SOURCES Electronic searches of PubMed and Embase were conducted from January 1992 to January 2020, using a combination of medical subject heading terms and key words to define concepts of endothelial dysfunction, pediatric critical illness, and outcomes. STUDY SELECTION Studies were included if they evaluated critically ill children with endothelial dysfunction, evaluated performance characteristics of assessment/scoring tools to screen for endothelial dysfunction, and assessed outcomes related to mortality, functional status, organ-specific outcomes, or other patient-centered outcomes. Studies of adults or premature infants (≤36 weeks gestational age), animal studies, reviews or commentaries, case series with sample size ≤10, and non-English language studies with the inability to determine eligibility criteria were excluded. DATA EXTRACTION Data were abstracted from each eligible study into a standard data extraction form along with risk of bias assessment. DATA SYNTHESIS We identified 62 studies involving 84 assessments of endothelial derived biomarkers indirectly linked to endothelial functions including leukocyte recruitment, inflammation, coagulation, and permeability. Nearly all biomarkers studied lacked specificity for vascular segment and organ systems. Quality assessment scores for the collected literature were low. CONCLUSIONS The Endothelial Subgroup concludes that there exists no single or combination of biomarkers to diagnose endothelial dysfunction in pediatric multiple organ dysfunction syndrome. Future research should focus on biomarkers more directly linked to endothelial functions and with specificity for vascular segment and organ systems.

Flush Flow Behaviour Affected by the Morphology of Intravascular Endoscope: A Numerical Simulation and Experimental Study

Background: Whilst intravascular endoscopy can be used to identify lesions and assess the deployment of endovascular devices, it requires temporary blockage of the local blood flow during observation, posing a serious risk of ischaemia.Objective: To aid the design of a novel flow-blockage-free intravascular endoscope, we explored changes in the haemodynamic behaviour of the flush flow with respect to the flow injection speed and the system design.Methods: We first constructed the computational models for three candidate endoscope designs (i.e., Model A, B, and C). Using each of the three endoscopes, flow patterns in the target vessels (straight, bent, and twisted) under three different sets of boundary conditions (i.e., injection speed of the flush flow and the background blood flowrate) were then resolved through use of computational fluid dynamics and in vitro flow experiments. The design of endoscope and its optimal operating condition were evaluated in terms of the volume fraction within the vascular segment of interest, as well as the percentage of high-volume-fraction area (PHVFA) corresponding to three cross-sectional planes distal to the microcatheter tip.Results: With a mild narrowing at the endoscope neck, Model B exhibited the highest PHVFA, irrespective of location of the cross-sectional plane, compared with Models A and C which, respectively, had no narrowing and a moderate narrowing. The greatest difference in the PHVFA between the three models was observed on the cross-sectional plane 2 mm distal to the tip of the microcatheter (Model B: 33% vs. Model A: 18%). The background blood flowrate was found to have a strong impact on the resulting volume fraction of the flush flow close to the vascular wall, with the greatest difference being 44% (Model A).Conclusion: We found that the haemodynamic performance of endoscope Model B outperformed that of Models A and C, as it generated a flush flow that occupied the largest volume within the vascular segment of interest, suggesting that the endoscope design with a diameter narrowing of 30% at the endoscope neck might yield images of a better quality.

Neuropathy - Exponent of Accelerated Involution in Uremia: The Role of Carbamylation

Premature loss of functional integrity of the nervous system in chronic renal failure (CRF) as a consequence of persistent biological activities of the general uremic milieu is almost identical to its structural and functional involution during the process of physiological ageing, but disproportionate and independent of chronological age. In the hyperuremic status of CRF (urea - carbamide), forced carbamylation, as a non-enzymatic post-translational modification (NEPTM) of proteins and amino acids, by changing their biological properties and decreasing proteolysis capacity, represents pathogenetic potential of intensified molecular ageing and accelerated, pathological involution. Physiological predisposition and the exposure of neuropathy before complications of other organs and organ systems in CRF, due to the simultaneous and mutually pathogenetically related uremic lesion and the tissue and vascular segment of the nervous system, direct interest towards proteomic analytical techniques of quantification of carbamylated products as biomarkers of uremic neurotoxicity. Hypothetically, identical to the already established applications of other NEPTM products in practice, they have the potential of clinical methodology in the evaluation of uremic neuropathy and its contribution to the general prediction, but also to the change of the conventional CRF classification. In addition, the identification and therapeutic control of the substrate of accelerated involution, responsible for the amplification of not only neurological but also general degenerative processes in CRF, is attractive in the context of the well-known attitude towards aging.

The effect of aortic esophageal fistula treatment after TEVAR with artificial vessel bypass（Single center clinical experience）

Objective: To investigate the effect of aortic esophageal fistula treatment after thoracic aortic endovascular repair (TEVAR) with artificial vessel bypass. Methods: The clinical data of 6 consecutive patients who received surgical treatment at Shanghai Deda Hospital from September 2019 to June 2021 due to aortic esophageal fistula after TEVAR were retrospectively analyzed. There were 6 males, aged (47.7±8.2) years old (range: 35-56 years old). All patients had recurrent fever, and 4 patients had positive blood cultures. According to the specific conditions of the patients, all patients underwent artificial blood vessel bypass and jejunostomy under general anesthesia without extracorporeal circulation. One case underwent artificially infected vascular segment resection and esophageal repair at the same time. 5 cases underwent artificial infection vascular resection, 4 of them underwent esophageal repair, and 1 case had a large intraoperative fistula and local resection of the esophagus. Sensitive antibacterial drugs were continued after the operation for 6 to 8 weeks. Results: There were 2 deaths in hospital, 1 case of large cerebral infarction early postoperatively, and 1 case of septic shock. The remaining 4 patients recovered well after the operation and were discharged. The follow-up period was 2 to 23 months. During the follow-up period, the remaining patients had no recurrence of infection and esophageal fistula. Conclusion ：In patients with aortic esophageal fistula after TEVAR, the establishment of artificial vascular bypass, the resection of the infected vascular segment, contemporaneous or staged esophageal repair, regular anti-infective treatment can obtain a good prognosis.

Algorithm of Pulmonary Vascular Segment and Centerline Extraction

Because pulmonary vascular lesions are harmful to the human body and difficult to detect, computer-assisted diagnosis of pulmonary blood vessels has become the focus and difficulty of the current research. An algorithm of pulmonary vascular segment and centerline extraction which is consistent with the physician’s diagnosis process is proposed for the first time. We construct the projection of maximum density, restore the vascular space information, and correct random walk algorithm to satisfy automatic and accurate segmentation of blood vessels. Construct a local 3D model to restrain Hessian matrix when extracting centerline. In order to assist the physician to make a correct diagnosis and verify the effectiveness of the algorithm, we proposed a visual expansion model. According to the 420 high-resolution CT data of lung blood vessels labeled by physicians, the accuracy of segmentation algorithm AOM reached 93%, and the processing speed was 0.05 s/frame, which achieved the clinical application standards.

Finite element simulation of the impedance response of a vascular segment as a function of changes in electrode configuration

Monitoring a biological tissue as a three dimensional (3D) model is of high importance. Both the measurement technique and the measuring electrode play substantial roles in providing accurate 3D measurements. Bioimpedance spectroscopy has proven to be a noninvasive method providing the possibility of monitoring a 3D construct in a real time manner. On the other hand, advances in electrode fabrication has made it possible to use flexible electrodes with different configurations, which makes 3D measurements possible. However, designing an experimental measurement set-up for monitoring a 3D construct can be costly and time consuming and would require many tissue models. Finite element modeling methods provide a simple alternative for studying the performance of the electrode and the measurement set-up before starting with the experimental measurements. Therefore, in this study we employed the COMSOL Multiphysics finite element modeling method for simulating the effects of changing the electrode configuration on the impedance spectroscopy measurements of a venous segment. For this purpose, the simulations were performed for models with different electrode configurations. The simulation results provided us with the possibility of finding the optimal electrode configuration including the geometry, number and dimensions of the electrodes, which can be later employed in the experimental measurement set-up.

Abstract 16541: Clinical and Imaging Phenotypes From a Registry of Segmental Arterial Mediolysis

Background: Segmental arterial mediolsyis (SAM) is a non-inflammatory arteriopathy that is increasingly being recognized; however, its clinical characteristics and natural history remain poorly defined. Methods: A retrospective, single-institution review of 20 patients presenting with arterial dissection, intramural hematoma, aneurysm, or occlusion between 2015 and 2020 was performed. To establish a non-invasive diagnosis of SAM, patients with FMD, inflammatory, or genetic arteriopathy were excluded by clinical, laboratory, and imaging criteria according to multidisciplinary guidelines. Patient demographics, clinical features, imaging findings, and management were assessed. Results: The average age of patients was 56 years; 75% were male. CAD was present in 15% of patients and 45% had hypertension; 55% were current or prior smokers. In patients without diagnosed CAD, the 10-year ASCVD risk score was 8.7% and the Framingham risk score was 6.8%. The average hemoglobin A1c was 5.6%. Acute onset abdominal pain (70%) was the most frequent presenting symptom. On average, two different arterial beds were affected at the time of diagnosis, most often in the abdomen. Arterial dissection was present in 75% of patients, and intramural hematoma was seen in 35% of cases. The most affected vessel was the superior mesenteric artery (50%), followed by the celiac, renal, and iliac arteries (35% each). Over a mean follow-up period of 20 months, all patients survived; two patients required intervention due to worsening clinical symptoms. Anticoagulation (AC) was utilized in 50% of cases, most commonly for one month. Long-term follow-up imaging was available in 11 patients; 3 patients (27%) had progression in lesion size over the first month. By 1 year, only 1 patient continued to show enlargement, with all others showing regression. Conclusions: This cohort provides longitudinal follow-up on both clinical and imaging characteristics of non-invasively diagnosed SAM. The condition shows a male predominance, typically manifesting in middle-aged patients with low to intermediate cardiovascular risk. While a subset of patients shows growth in size of the affected vascular segment over the first month, longer follow-up imaging demonstrates regression.

Contemporary issues of femoropopliteal stenting

<p>Peripheral artery disease (PAD) is one of the most common cardiovascular diseases with serious sequelae. Every year, 120–500 amputations are performed per 1 million people worldwide. The severe consequences of amputation include the mental trauma caused by loss of a limb, disability and a real risk of death for the patient, since the mortality rate associated with the development of gangrene remains extremely high. PAD is most frequently located in the femoral-popliteal segment, which is the longest vascular segment in the human body. Over the past decade, the endovascular approach has become the main therapeutic strategy for PAD, given its lower risk of complications and comparable efficacy to open interventions. Femoral-popliteal stenting provides advantages over balloon angioplasty, preventing vessel wall recoil and providing necessary frame support.<br />This review aims to describe the latest progress of endovascular surgery for the treatment of femoral-popliteal artery disease and to discuss its limitations.<br />The introduction of nitinol stents and new drug coated stents into clinical practice has improved the results of femoral-popliteal endovascular treatment. Despite this, stent failure remains a pressing problem that significantly impacts the results of endovascular treatment of atherosclerotic lesions of lower limb arteries.</p><p>Received 6 June 2019. Revised 8 October 2019. Accepted 10 October 2019.</p><p><strong>Funding:</strong> The study did not have sponsorship.</p><p><strong>Conflict of interest:</strong> Authors declare no conflict of interest.</p><p><strong>Author contributions</strong><br />Conception and design: D.U. Malaev, A.R. Tarkova, A.A. Prokhorkhin, A.A. Boykov<br />Drafting the article: D.U. Malaev, A.A. Prokhorkhin, A.A. Boykov<br />Critical revision of the article: D.L. Merson, A.Yu. Vinogradov, V.I. Baystrukov, E.I. Kretov<br />Final approval of the version to be published: D.U. Malaev, A.R. Tarkova, A.A. Prokhorkhin, D.L. Merson, A.Yu. Vinogradov, V.I. Baystrukov, A.A. Boykov, E.I. Kretov, M.V. Pryamov</p>

Aortic Isthmus Doppler Velocimetry in Fetuses with Intrauterine Growth Restriction: A Literature Review

Intrauterine growth restriction (IUGR) is associated with poor perinatal prognosis and a higher risk of stillbirth, neonatal death, and cerebral palsy. Its detection and the evaluation of its severity by new Doppler velocimetric parameters, such as aortic isthmus (AoI), are of great relevance for obstetrical practice. The AoI is a vascular segment that represents a point of communication between the right and left fetal circulations. It is considered to be a functional arterial shunt that reflects the relationship between the systemic and cerebral impedances, and has recently been proposed as a tool to detect the status of hemodynamic balance and prognosis of IUGR in fetuses. In the present review, we noticed that in healthy fetuses, the AoI net flow is always antegrade, but in fetuses with IUGR the deterioration of placental function leads to progressive reduction in its flow until it becomes mostly retrograde; this point is associated with a drastic reduction in oxygen delivery to the brain. The more impaired the AoI flow is, the greater is the risk of impairment in the Doppler velocimetry of other vessels; and the alterations of the AoI Doppler seem to precede other indicators of severe hypoxemia. Although there seems to be an association between the presence of retrograde flow in the AoI and the risk of long-term neurologic disability, its role in the prediction of perinatal morbi-mortality remains unclear. The AoI Doppler seems to be a promising tool in the management of fetuses with IUGR, but more studies are needed to investigate its employment in clinical practice.

No effect of fitness on brachial or forearm vascular function during acute inflammation in young adults

Acute inflammation is associated with increased risk of cardiovascular events and impaired vasodilatory capacity. Vasodilatory capacity can be measured in different segments of the arterial tree; however, it is unknown if the effects of acute inflammation are vascular segment-specific or if inflammation-induced dysfunction can be attenuated by factors that modulate cardiovascular risk, such as high cardiorespiratory fitness. The purpose of this study was to determine the effect of acute inflammation and fitness on conduit artery, resistance artery, and microvascular function in healthy, young adults. Vascular function was assessed at baseline and 24 h after a typhoid vaccination in 11 low-fit (5 male, 24 yr of age, 34.5 ± 2.9 ml·kg−1·min−1 peak O2 uptake (V̇o2peak)] and 12 high-fit (7 male, 27 yr of age, 56.4 ± 9.7 ml·kg−1·min−1 V̇o2peak) young adults. Vascular assessments included flow-mediated dilation (FMD) of the brachial artery, forearm reactive hyperemia (RH) via venous occlusion plethysmography, and near-infrared spectroscopy (NIRS) during a 5-min arterial occlusion. Acute inflammation was evident with increases in IL-6 and C-reactive protein ( P < 0.01), and mean arterial pressure did not change ( P = 0.33). FMD was lower in the high-fit group, yet it was reduced in both groups at 24 h, even after controlling for shear ( P < 0.05). No effect of acute inflammation was observed for RH or NIRS ( P > 0.05). Acute inflammation had nonuniform effects on vascular function throughout the arterial tree in young adults, and fitness did not alter the vascular response. This suggests that cardiorespiratory fitness may not protect the vasculature during acute inflammation in young adults in the absence of age- or disease-related decline in vascular function.