Short-Term Outcomes and Efficacy of Percutaneous Deep Vein Arterialization for No-Option Critical Limb Ischemia: A Systematic Review and Meta-Analysis

BACKGROUND: Percutaneous deep vein arterialization (pDVA) is considered a treatment modality in patients with no-option critical limb ischemia. However, there is still a paucity of evidence regarding its safety and efficacy. DATA SOURCES: MEDLINE (via PubMed), Embase and Web of Science databases as well as the CENTRAL registry up to the end of June 2023. METHODS: This review adhered to the PRISMA guidelines (PROSPERO registration no. CRD42023445171). The risk of bias was assessed using the methodological index for non-randomized studies (MINORS). Primary endpoints included technical success, overall survival and limb salvage during the follow-up. Amputation-free survival at 30 days, 6 months and 1 year as well as complete wound healing, major adverse limb events and reintervention were investigated as secondary outcomes. RESULTS: Five observational studies, comprising 208 patients (142 Rutherford class 5/77 Rutherford class 6), were included. MINORS revealed a low risk of bias. The meta-analysis reached a pooled technical success rate of 96.2% (95% CI: 91.5-98.4), an overall survival of 82.8% (95% CI: 70.5-95.2) and a limb salvage rate of 77.2% (95% CI: 65.2-89.1) during the follow-up. The amputation-free survival at 30 days, 6 months and 1 year was 87.8%, 68.7% and 65.6%, respectively. Furthermore, pDVA resulted in a complete wound healing rate of 53.4% (95% CI: 30.3-76.5). The pooled reintervention rate was as high as 46.7% (37.1-56.3%). CONCLUSIONS: PDVA seems a feasible bail-out strategy for patients with no option for routine treatment of CLTI. However, due to the small number of studies, the strength of the evidence is low

A Machine Learning-Based Framework for Clustering Residential Electricity Load Profiles to Enhance Demand Response Programs

Load shapes derived from smart meter data are frequently employed to analyze daily energy consumption patterns, particularly in the context of applications like Demand Response (DR). Nevertheless, one of the most important challenges to this endeavor lies in identifying the most suitable consumer clusters with similar consumption behaviors. In this paper, we present a novel machine learning based framework in order to achieve optimal load profiling through a real case study, utilizing data from almost 5000 households in London. Four widely used clustering algorithms are applied specifically K-means, K-medoids, Hierarchical Agglomerative Clustering and Density-based Spatial Clustering. An empirical analysis as well as multiple evaluation metrics are leveraged to assess those algorithms. Following that, we redefine the problem as a probabilistic classification one, with the classifier emulating the behavior of a clustering algorithm,leveraging Explainable AI (xAI) to enhance the interpretability of our solution. According to the clustering algorithm analysis the optimal number of clusters for this case is seven. Despite that, our methodology shows that two of the clusters, almost 10\% of the dataset, exhibit significant internal dissimilarity and thus it splits them even further to create nine clusters in total. The scalability and versatility of our solution makes it an ideal choice for power utility companies aiming to segment their users for creating more targeted Demand Response programs.Comment: 29 pages, 19 figure

Ifabp Levels Predict Visceral Malperfusion in the First Hours After Open Thoracoabdominal Aortic Repair

INTRODUCTION: Intestinal ischemia after open thoracoabdominal aortic repairs, is a rare but devastating complication, associated with high mortality. Notoriously challenging to diagnose, visceral malperfusion necessitates immediate surgical attention. Intestinal fatty acid-binding protein (IFABP) has been proposed as a biomarker for the diagnosis of intestinal wall damage. In this prospectively conducted, observational study we evaluated the diagnostic capacity of IFABP levels in patients\u27 serum and their correlation with visceral malperfusion. METHODS: 23 patients undergoing open thoracoabdominal aortic repairs were included in this study and 8 of them were diagnosed postoperatively with visceral malperfusion-defined as a partial or complete thrombotic occlusion of the superior mesenteric artery and/or the coeliac trunk. IFABP levels and laboratory parameters often associated with intestinal ischemia (leucocytes, CRP, PCT and lactate) were measured at baseline, directly postoperatively, and at 12, 24 and 48 h after surgery. Postoperative visceral malperfusion-as revealed in CT angiography-was assessed and the predictive ability of IFABP levels to detect visceral malperfusion was evaluated with receiver-operator curve analysis. RESULTS: Patients with visceral malperfusion had a relevant risk for a fatal outcome ( CONCLUSION: We conclude, that IFABP measurements during the first postoperative hours after open thoracoabdominal aortic surgery can be a valuable tool for reliable and timely detection of visceral malperfusion

The Use of Stock Options for Resource Allocation and Management on Content Delivery Networks

Η παρούσα διπλωματική εργασία πραγματεύεται τη χρήση δικαιωμάτων προαίρεσης ως μία αποτελεσματική μέθοδο κατανομής και διαχείρισης πόρων, οι οποίοι διανέμονται από σύγχρονα δίκτυα διανομής περιεχομένων. Επιχειρείται η αλληγορική συσχέτιση μεταξύ των επιστημών των Οικονομικών και της Πληροφορικής εξετάζοντας τη χρησιμότητα ενός καθαρά οικονομικού όρου - όπως είναι τα δικαιώματα προαίρεσης - για τη δημιουργία ενός προδραστικού μοντέλου διαχείρισης πόρων, το οποίο μπορεί να εφαρμοστεί άμεσα στο χώρο των δικτύων διανομής περιεχομένου, δηλαδή στην πλειοψηφία των υποδομών παρόχων περιεχομένου της καθημερινότητας της ψηφιακής εποχής. Τα εισαγωγικά κεφάλαια παρουσιάζουν τον ορισμό των σύγχρονων δικτύων παροχής περιεχομένου και υπογραμμίζουν την ανάγκη για αποτελεσματική διαχείριση πόρων. Ταυτόχρονα, παρουσιάζεται η έννοια και η σημασία της παροχής ποιότητας υπηρεσιών στην παρούσα εποχή, μαζί με τις βασικές τεχνικές με τις οποίες αυτή επιτυγχάνεται στη σύγχρονη αγορά. Στη συνέχεια παρουσιάζεται το υπάρχον μοντέλο πρόβλεψης για την προσομοίωση της αγοράς, μαζί με τους μηχανισμούς και τα εμπλεκόμενα μέρη. Το μοντέλο αυτό χρησιμεύει ως θεμελιώδης ιδέα για την περαιτέρω έρευνα και το μοντέλο που προτείνεται στο πλαίσιο της εργασίας. Αναφέρονται επίσης οι βασικές έννοιες με τις οποίες ασχολείται η εργασία - δηλαδή οι ορισμοί της Δευτερεύουσας Αγοράς και των Δικαιωμάτων Προαίρεσης, οι οποίοι αναλύονται σε βάθος στα κεφάλαια 3 και 4 αντίστοιχα. Παρουσιάζεται η εξίσωση Black-Scholes για την αξιολόγηση των δικαιωμάτων προαίρεσης αγοράς μετοχών, στην οποία βασίζεται το προτεινόμενο μοντέλο, το οποίο με τη σειρά του παρουσιάζεται στα επόμενα κεφάλαια. Στο κεφάλαιο 5 αναλύονται τα σενάρια της αγοράς με βάση την ανάγκη χρήσης και εκμετάλλευσης των δικαιωμάτων προαίρεσης αγοράς μετοχών, υπογραμμίζοντας τη σημασία τους, ενώ στο κεφάλαιο 6 παρουσιάζονται οι βασικές μέθοδοι και πολιτικές κοστολόγησης και τιμολόγησης από την πλευρά των δικτύων διανομής περιεχομένου. Το κεφάλαιο 7 παρουσιάζει το προτεινόμενο μοντέλο έχοντας ως βάση όλες τις προαναφερθείσες έννοιες. Ο προτεινόμενος αλγόριθμος παρουσιάζεται βήμα προς βήμα και υπογραμμίζει τη διαφοροποίηση του μοντέλου σε σχέση με άλλα μοντέλα. Τα σενάρια προσομοίωσης του μοντέλου παρουσιάζονται στο κεφάλαιο 8, όπου καταγράφονται οι μετρήσεις και αναλύονται τα αποτελέσματα στο πλαίσιο της συμβολής του μοντέλου προς το στόχο της αποτελεσματικότερης διαχείρισης των πόρων στην αγορά των δικτύων διανομής περιεχομένου. Το κεφάλαιο 9 καταγράφει τα συμπεράσματα και παρουσιάζει ιδέες και ερωτήματα που μπορεί να αποτελέσουν αντικείμενο περαιτέρω μελέτης, ενώ στο τέλος της εργασίας αναφέρονται το βιβλιογραφικό έργο και άλλες πηγές, οι οποίες συνέβαλαν στην εκπόνηση της διπλωματικής εργασίας. Επίσης εμπεριέχεται ένα τριμερές υπόμνημα. Στο πρώτο μέρος παρουσιάζονται πολιτικές γνωστών παρόχων της εποχής για την κοστολόγηση πόρων. Το δεύτερο μέρος περιέχει τις βασικές συναρτήσεις του πηγαίου κώδικα Java του προγράμματος, το οποίο αναπτύχθηκε για τις προσομοιώσεις του προτεινόμενου μοντέλου ενώ το τρίτο μέρος περιέχει τον πίνακα τιμολόγησης του δικτύου διανομής περιεχομένου, όπως αυτός χρησιμοποιείται στις προσομοιώσεις.This thesis presents and examines the use of Stock Options as an efficient allocation and management method of resources, which are distributed from modern infrastructure Content Delivery Networks. The allegorical correlation between the scientific fields of Economics and Computer Science is attempted by examining the usefulness of a purely financial term - such as Stock Options - for the creation of a proactive resource management model, which can be directly applied to content distribution networks, namely the majority of content providers' infrastructures in the everyday life of the digital age. The introductory chapters present the definition of modern Content Delivery Networks and highlight the need for efficient resource management. The concept and the importance of providing service quality in the present era are also presented, along with the basic techniques by which it is achieved in the modern CDN ecosystem. Next, an existing resource prediction model of the market’s simulation is presented, along with its mechanisms and the parties involved. This model serves as the fundamental idea on our further research and our own proposed model. The basic concepts that the thesis is deeply concerned with - namely the definitions of the Secondary Market and the Stock Options - are also introduced. The core concepts, namely the Secondary Market and the Stock Options are analyzed in detail in chapters 3 and 4 respectively. We present the Black-Scholes options pricing formula for the evaluation of stock options, based on which the proposed model of work is presented, which in turn is presented in the following chapters. Chapter 5 analyzes market scenarios based on the need to use and exploit stock options, highlighting their importance, while in chapter 6 fundamental CDN cost planning pricing methods and policies are presented. Chapter 7 presents the proposed model on the basis of all the previously mentioned concepts. The proposed algorithm is laid out step by step and highlights the model’s differentiation compared to other models. The conversion of the algorithm into actual, scenarios of our proposed framework is presented in chapter 8, where the metrics are presented and the results of the simulated scenarios are analyzed in the context of the model’s contribution towards the goal of more efficient resource management in the area of Content Delivery Networks. Chapter 9 serves as the conclusion of the thesis and presents ideas and questions that may be the subject of further study, while at the end of the thesis references of the literature work and of all other sources that contributed to the creation of the thesis are recorded. Τhere is also a three-part annex. In the first part, examples of cost pricing policies of real-life CDN’s are presented. The second part contains the fundamental functions of the Java source code that was developed for the simulation of the proposed model. Finally, the third part contains the CDN pricing table used in the simulation

The Nephrocheck Bedside System for Detecting Stage 3 Acute Kidney Injury After Open Thoracoabdominal Aortic Repair

Acute kidney injury (AKI) is a common complication after complex aortic procedures and it is associated with relevant mortality and morbidity. Biomarkers for early and specific AKI detection are lacking. The aim of this work is to investigate the reliability of the NephroCheck bedside system for diagnosing stage 3 AKI following open aortic surgery. In this prospective, multicenter, observational study,- https://clinicaltrials.gov/ct2/show/NCT04087161 -we included 45 patients undergoing open thoracoabdominal aortic repair. AKI risk (AKIRisk-Index) was calculated from urine samples at 5 timepoints: baseline, immediately postoperatively and at 12, 24, 48, and 72 h post-surgery. AKIs were classified according to the KDIGO criteria. Contributing factors were identified in univariable and multivariable logistic regression. Predictive ability was assessed with the area under the receiver operator curve (ROCAUC). Among 31 patients (68.8%) that developed AKIs, 21 (44.9%) developed stage-3 AKIs, which required dialysis. AKIs were correlated with increased in-hospital mortality (p = .006), respiratory complications (p \u3c .001), sepsis (p \u3c .001), and multi-organ dysfunction syndrome (p \u3c .001). The AKIRisk-Index showed reliable diagnostic accuracy starting at 24 h post-surgery (ROCAUC: .8056, p = .001). In conclusion, starting at 24 h after open aortic repair, the NephroCheck system showed adequate diagnostic accuracy for detecting the patients at risk for stage 3 AKIs

Postoperative Bioactive Adrenomedullin is Associated With the Onset of Ards and Adverse Outcomes in Patients Undergoing Open Thoracoabdominal Aortic Surgery

Cytokine-mediated systemic inflammation after open thoracoabdominal aortic aneurysm (TAAA) repairs plays a pivotal role in disrupting circulatory homeostasis, potentially leading to organ dysfunction. The bioactive form of adrenomedullin (bio-ADM) is a peptide hormone with immunomodulatory and vasomotor effects, making it a potential diagnostic agent in these cases. This retrospective, bicentric study, conducted between January 2019 and December 2022, recruited 36 elective open TAAA repair patients in two German centres. Serum and plasma samples were collected at multiple time points to measure bio-ADM levels. The primary objective was to evaluate the association of bio-ADM levels with the onset of acute respiratory distress syndrome (ARDS), with secondary endpoints focusing on mortality and SIRS-related morbidity. Results showed a significant association between postoperative bio-ADM levels (12-48 h after surgery) and the onset of ARDS (p \u3c .001), prolonged ventilation (p = .015 at 12h after surgery), atrial fibrillation (p \u3c .001), and mortality (p = .05 at 24h). The biomarker was also strongly associated with sepsis (p = .01 at 12 h) and multi-organ dysfunction syndrome (MODS) (p = .02 at 24 h after surgery). The study underscores the potential utility of bio-ADM as a diagnostic tool for identifying patients at risk of postoperative complications following open TAAA repairs

Factors Associated with Early Mortality in Acute Type A Aortic Dissection-A Single-Centre Experience

BACKGROUND: Acute aortic dissection type A (AADA) is a surgical emergency with relevant mortality and morbidity despite improvements in current management protocols. Identifying patients at risk of a fatal outcome and controlling the factors associated with mortality remain of paramount importance. METHODS: In this retrospective observational study, we reviewed the medical records of 117 patients with AADA, who were referred to our centre and operated on between 2005 and 2021. Preoperative, intraoperative, and postoperative variables were analysed and tested for their correlation with in-hospital mortality. RESULTS: The overall survival rate was 83%. Preoperatively, factors associated with mortality were age ( CONCLUSIONS: In this retrospective analysis, atrial fibrillation, oral anticoagulation, hypertension, and age were significantly correlated with mortality. Postoperatively, acute kidney injury, acute heart failure, sepsis, and focal neurological deficits were correlated with in-hospital mortality, and focal neurological deficit has been identified as a significant predictor of fatal outcomes. Early detection and interdisciplinary management of at-risk patients remain crucial throughout the postoperative phase

IFABP levels predict visceral malperfusion in the first hours after open thoracoabdominal aortic repair

IntroductionIntestinal ischemia after open thoracoabdominal aortic repairs, is a rare but devastating complication, associated with high mortality. Notoriously challenging to diagnose, visceral malperfusion necessitates immediate surgical attention. Intestinal fatty acid-binding protein (IFABP) has been proposed as a biomarker for the diagnosis of intestinal wall damage. In this prospectively conducted, observational study we evaluated the diagnostic capacity of IFABP levels in patients' serum and their correlation with visceral malperfusion.Methods23 patients undergoing open thoracoabdominal aortic repairs were included in this study and 8 of them were diagnosed postoperatively with visceral malperfusion—defined as a partial or complete thrombotic occlusion of the superior mesenteric artery and/or the coeliac trunk. IFABP levels and laboratory parameters often associated with intestinal ischemia (leucocytes, CRP, PCT and lactate) were measured at baseline, directly postoperatively, and at 12, 24 and 48 h after surgery. Postoperative visceral malperfusion—as revealed in CT angiography—was assessed and the predictive ability of IFABP levels to detect visceral malperfusion was evaluated with receiver-operator curve analysis.ResultsPatients with visceral malperfusion had a relevant risk for a fatal outcome (p = .001). IFABP levels were significantly elevated directly postoperatively and at 12 h after surgery in cases of visceral malperfusion. High IFABP concentrations in serum detected visceral malperfusion accurately during the first 12 h after surgery, with the maximum diagnostic ability achieved immediately after surgery (AUC 1, Sensitivity 100%, Specificity 100%, p < .001).ConclusionWe conclude, that IFABP measurements during the first postoperative hours after open thoracoabdominal aortic surgery can be a valuable tool for reliable and timely detection of visceral malperfusion

Pathomechanisms of ALS8: altered autophagy and defective RNA binding protein (RBP) homeostasis due to the VAPB P56S mutation.

Mutations in RNA binding proteins (RBPs) and in genes regulating autophagy are frequent causes of familial amyotrophic lateral sclerosis (fALS). The P56S mutation in vesicle-associated membrane protein-associated protein B (VAPB) leads to fALS (ALS8) and spinal muscular atrophy (SMA). While VAPB is primarily involved in the unfolded protein response (UPR), vesicular trafficking and in initial steps of the autophagy pathway, the effect of mutant P56S-VAPB on autophagy regulation in connection with RBP homeostasis has not been explored yet. Examining the muscle biopsy of our index ALS8 patient of European origin revealed globular accumulations of VAPB aggregates co-localised with autophagy markers LC3 and p62 in partially atrophic and atrophic muscle fibres. In line with this skin fibroblasts obtained from the same patient showed accumulation of P56S-VAPB aggregates together with LC3 and p62. Detailed investigations of autophagic flux in cell culture models revealed that P56S-VAPB alters both initial and late steps of the autophagy pathway. Accordingly, electron microscopy complemented with live cell imaging highlighted the impaired fusion of accumulated autophagosomes with lysosomes in cells expressing P56S-VAPB. Consistent with these observations, neuropathological studies of brain and spinal cord of P56S-VAPB transgenic mice revealed signs of neurodegeneration associated with altered protein quality control and defective autophagy. Autophagy and RBP homeostasis are interdependent, as demonstrated by the cytoplasmic mis-localisation of several RBPs including pTDP-43, FUS, Matrin 3 which often sequestered with P56S-VAPB aggregates both in cell culture and in the muscle biopsy of the ALS8 patient. Further confirming the notion that aggregation of the RBPs proceeds through the stress granule (SG) pathway, we found persistent G3BP- and TIAR1-positive SGs in P56S-VAPB expressing cells as well as in the ALS8 patient muscle biopsy. We conclude that P56S-VAPB-ALS8 involves a cohesive pathomechanism of aberrant RBP homeostasis together with dysfunctional autophagy