The Circle of Willis Status Influences Neurological Complications of Carotid Endarterectomy with Contralateral Carotid Occlusion.

BACKGROUND: To evaluate the impact of anatomical variations in the Circle of Willis (CoW) on immediate neurological events (INEs) after carotid endarterectomy (CEA) without shunting in patients with contralateral carotid occlusion (CCO). METHODS: Single-center retrospective study. Patient's demographic and clinical outcomes data were prospectively collected. CoW segments were reviewed retrospectively. Between January 2013 and May 2018, 2090 patients underwent CEA under general anesthesia, CCO was found in 113 (5.4%) patients. CoW segments were classified as normal, hypoplastic (diameter ˂0.8 mm), or absent based on computed tomography angiography. We studied the CoW segments as 2 collateral networks connecting the basilar artery and the ipsilateral middle cerebral artery: a short semicircle (first segment of the ipsilateral posterior cerebral artery [P1] and posterior communicating artery [Pcom] segment) and a long semicircle (contralateral P1, Pcom, and both first segments of the anterior cerebri artery (A1) anterior communicating artery (Acom)). INE was defined as any transient ischemic attack or stroke diagnosed immediately after the procedure. RESULTS: Out of the 113 patients, 46 underwent endarterectomy with shunting. We further excluded 16 patients from the assessment of the CoW due to unavailability or inadequate quality of computed tomography angiography. Of the 113 patients, 2 had strokes, 1 with shunting that occurred hrs after surgery. Besides the other stroke case, 4 INE were observed, all without the use of a shunt. Of the 51 patients with CoW assessment, 10 (19.6%) had a complete CoW, while 21 (41.2%) patients had only 1 semicircle intact (10 short and 11 long intact semicircles), and none of these patients experienced an INE. A total of 20 (39%) patients had both the long and short semicircles incomplete, of which 4 (7.8%) cases had an INE. In all INE cases, at least 1 of the Pcom was absent or hypoplastic. The absence of both Pcom was a strong predictor of incident INE [odds ratio = 11.10 (confidence interval: 1.04-118.60)] for INE. CONCLUSIONS: Patients with CCO and insufficient CoW collateral flow support are at an increased risk of INE, including stroke, in the absence of shunt protection during CEA cross-clamping. Shunting should always be considered when the collateral flow between the ipsilateral middle cerebral artery and the basilar artery is compromised in CCO patients.

MicroRNA Profiling in Papillary Thyroid Cancer.

Genetic alterations are well known to be related to the pathogenesis and prognosis of papillary thyroid carcinoma (PTC). Some miRNA expression dysregulations have previously been described in the context of cancer development including thyroid carcinoma. In our study, we performed original molecular diagnostics on tissue samples related to our own patients. We aimed to identify all dysregulated miRNAs in potential association with PTC development via sequencing much higher numbers of control-matched PTC tissue samples and analyzing a wider variety of miRNA types than previous studies. We analyzed the expression levels of 2656 different human miRNAs in the context of 236 thyroid tissue samples (118 tumor and control pairs) related to anonymized PTC cases. Also, KEGG pathway enrichment analysis and GO framework analysis were used to establish the links between miRNA dysregulation and certain biological processes, pathways of signaling, molecular functions, and cellular components. A total of 30 significant differential miRNA expressions with at least ±1 log2 fold change were found related to PTC including, e.g., miR-551b, miR-146b, miR-221, miR-222, and miR-375, among others, being highly upregulated, as well as miR-873 and miR-204 being downregulated. In addition, we identified miRNA patterns in vast databases (KEGG and GO) closely similar to that of PTC including, e.g., miRNA patterns of prostate cancer, HTLV infection, HIF-1 signaling, cellular responses to growth factor stimulus and organic substance, and negative regulation of gene expression. We also found 352 potential associations between certain miRNA expressions and states of clinicopathological variables. Our findings-supported by the largest case number of original matched-control PTC-miRNA relation research-suggest a distinct miRNA expression profile in PTC that could contribute to a deeper understanding of the underlying molecular mechanisms promoting the pathogenesis of the disease. Moreover, significant miRNA expression deviations and their signaling pathways in PTC presented in our study may serve as potential biomarkers for PTC diagnosis and prognosis or even therapeutic targets in the future.

Analysis of SIRT1 Gene SNPs and Clinical Characteristics in Medication-Related Osteonecrosis of the Jaw.

Certain genetic factors, including single-nucleotide polymorphisms (SNPs) in the SIRT1 gene, have been linked to medication-related osteonecrosis of the jaw (MRONJ). This study examined four SNPs in the SIRT1 gene and implemented multivariate statistical analysis to analyze genetic and clinical factors in MRONJ patients. Genomic DNA was isolated from peripheral blood samples of 63 patients of European origin treated for MRONJ, and four SNP genotypes in the gene encoding the SIRT-1 protein were determined by Sanger sequencing. The allele frequencies measured in the MRONJ population were compared with allele frequencies measured in the European population in the National Center for Biotechnology Information Allele Frequency Aggregator (NCBI ALFA) database. Genetic and clinical factors were examined with multivariate statistical analysis. A C:A allele distribution ratio of 77.8:22.2 was measured in the rs932658 SNP. In the ALFA project, a C:A allele distribution ratio of 59.9:40.1 was detected in the European population, which was found to be a significant difference (p = 4.5 × 10-5). Multivariate statistical analysis revealed a positive correlation (0.275) between the genotype of SNP rs932658 and the number of stages improved during appropriate MRONJ therapy. It is concluded that allele A in SNP rs932658 in the SIRT1 gene acts as a protective factor in MRONJ.

Development and initial validation of an endoscopic part-task training box.

BACKGROUND AND STUDY AIMS: There is currently no objective and validated methodology available to assess the progress of endoscopy trainees or to determine when technical competence has been achieved. The aims of the current study were to develop an endoscopic part-task simulator and to assess scoring system validity. METHODS: Fundamental endoscopic skills were determined via kinematic analysis, literature review, and expert interviews. Simulator prototypes and scoring systems were developed to reflect these skills. Validity evidence for content, internal structure, and response process was evaluated. RESULTS: The final training box consisted of five modules (knob control, torque, retroflexion, polypectomy, and navigation and loop reduction). A total of 5 minutes were permitted per module with extra points for early completion. Content validity index (CVI)-realism was 0.88, CVI-relevance was 1.00, and CVI-representativeness was 0.88, giving a composite CVI of 0.92. Overall, 82 % of participants considered the simulator to be capable of differentiating between ability levels, and 93 % thought the simulator should be used to assess ability prior to performing procedures in patients. Inter-item assessment revealed correlations from 0.67 to 0.93, suggesting that tasks were sufficiently correlated to assess the same underlying construct, with each task remaining independent. Each module represented 16.0 % - 26.1 % of the total score, suggesting that no module contributed disproportionately to the composite score. Average box scores were 272.6 and 284.4 (P = 0.94) when performed sequentially, and average score for all participants with proctor 1 was 297.6 and 308.1 with proctor 2 (P = 0.94), suggesting reproducibility and minimal error associated with test administration. CONCLUSION: A part-task training box and scoring system were developed to assess fundamental endoscopic skills, and validity evidence regarding content, internal structure, and response process was demonstrated.

Robotic right lower lobectomy for a persistent large pulmonary arteriovenous malformation following repeated coil embolization.

Pulmonary arteriovenous malformations create continuous shunting of unoxygenated blood through the lungs into the systemic circulation. These malformations are asymptomatic if small, but cause serious symptoms as they grow in size. Treatment primarily consists of endovascular embolization; lobectomy is preserved for recurring or endovascularly untreatable cases. We describe a case of a 24-year-old man who was first treated with coil embolization 10 years previously, with complete symptom resolution. However, more recently he noted recurrent exercise intolerance, with shortness of breath and hypoxemia. After repeat re-embolization, a computed tomography scan noted some persistent flow. Given the patient's young age, we considered resection as a definite therapy. The patient underwent an uncomplicated robot-assisted right lower lobectomy. Afterward, his symptoms resolved completely. In selected cases, robotic lobectomy for pulmonary arteriovenous malformation is feasible and safe.

Robot-assisted vascular surgery: literature review, clinical applications, and future perspectives.

Although robot-assisted surgical procedures using the da Vinci robotic system (Intuitive Surgical, Sunnyvale, CA) have been performed in more than 13 million procedures worldwide over the last two decades, the vascular surgical community has yet to fully embrace this approach (Intuitive Surgical Investor Presentation Q3 (2023) https://investor.intuitivesurgical.com/static-files/dd0f7e46-db67-4f10-90d9-d826df00554e . Accessed February 22, 2024). In the meantime, endovascular procedures revolutionized vascular care, serving as a minimally invasive alternative to traditional open surgery. In the pursuit of a percutaneous approach, shorter postoperative hospital stay, and fewer perioperative complications, the long-term durability of open surgical vascular reconstruction has been compromised (in Lancet 365:2179-2186, 2005; Patel in Lancet 388:2366-2374, 2016; Wanhainen in Eur J Vasc Endovasc Surg 57:8-93, 2019). The underlying question is whether the robotic-assisted laparoscopic vascular surgical approaches could deliver the robustness and longevity of open vascular surgical reconstruction, but with a minimally invasive delivery system. In the meantime, other surgical specialties have embraced robot-assisted laparoscopic technology and mastered the essential vascular skillsets along with minimally invasive robotic surgery. For example, surgical procedures such as renal transplantation, lung transplantation, and portal vein reconstruction are routinely being performed with robotic assistance that includes major vascular anastomoses (Emerson in J Heart Lung Transplant 43:158-161, 2024; Fei in J Vasc Surg Cases Innov Tech 9, 2023; Tzvetanov in Transplantation 106:479-488, 2022; Slagter in Int J Surg 99, 2022). Handling and dissection of major vascular structures come with the inherent risk of vascular injury, perhaps the most feared complication during such robotic procedures, possibly requiring emergent vascular surgical consultation. In this review article, we describe the impact of a minimally invasive, robotic approach covering the following topics: a brief history of robotic surgery, components and benefits of the robotic system as compared to laparoscopy, current literature on "vascular" applications of the robotic system, evolving training pathways and future perspectives.

Non-Invasive Tools in Perioperative Stroke Risk Assessment for Asymptomatic Carotid Artery Stenosis with a Focus on the Circle of Willis.

This review aims to explore advancements in perioperative ischemic stroke risk estimation for asymptomatic patients with significant carotid artery stenosis, focusing on Circle of Willis (CoW) morphology based on the CTA or MR diagnostic imaging in the current preoperative diagnostic algorithm. Functional transcranial Doppler (fTCD), near-infrared spectroscopy (NIRS), and optical coherence tomography angiography (OCTA) are discussed in the context of evaluating cerebrovascular reserve capacity and collateral vascular systems, particularly the CoW. These non-invasive diagnostic tools provide additional valuable insights into the cerebral perfusion status. They support biomedical modeling as the gold standard for the prediction of the potential impact of carotid artery stenosis on the hemodynamic changes of cerebral perfusion. Intraoperative risk assessment strategies, including selective shunting, are explored with a focus on CoW variations and their implications for perioperative ischemic stroke and cognitive function decline. By synthesizing these insights, this review underscores the potential of non-invasive diagnostic methods to support clinical decision making and improve asymptomatic patient outcomes by reducing the risk of perioperative ischemic neurological events and preventing further cognitive decline.

Related adjustment of firm production after demand shocks.

Multiproduct firms often diversify into technologically related activities to exploit efficiencies of joint production; however, unrelated products in the company's portfolio provide access to distinct markets and can help to avoid industry-specific shocks. Yet, the underlying mechanisms of related and unrelated diversification are still poorly understood. Here we investigate diversification decisions of firms in periods when corporations' markets are hit by a demand shocks. In these times, cost efficiency considerations might drive firms to reduce costs by narrowing product portfolios and focusing on combinations of technologically related products, in which economies of scope and mutual capabilities can be exploited. To test this hypothesis, we consider two measures of demand shocks, decreasing sales volumes on the product market and increasing import competition; and analyze their association with changes of product portfolios of Hungarian firms in the 2003-2012 period. We find that production has become more coherent in terms of technological relatedness after firms were exposed to demand shocks. Evidence suggests related adjustment of firm production after demand shocks such that products unrelated to firms' core product are dropped from the portfolio but related products are added.

Laparoscopic cholecystectomy after a quarter century: why do we still convert?

BACKGROUND: Laparoscopic cholecystectomy (LC) is the gold standard procedure for gallbladder removal. However, conversion to open surgery is sometimes needed. The factors underlying a surgeon's decision to convert a laparoscopic case to an open case are complex and poorly understood. With decreasing experience in open cholecystectomy, this procedure is however no longer the "safe" alternative it once was. With such an impending paradigm shift, this study aimed to identify the main reasons for conversion and ultimately to develop guidelines to help reduce the conversion rates. METHODS: Using the National Surgical Quality Improvement Program (NSQIP) database and financial records, the authors retrospectively reviewed 1,193 cholecystectomies performed at their institution from 2002 to 2009 and identified 70 conversions. Two independent surgeons reviewed the operative notes and determined the reasons for conversion. The number of ports at the time and the extent of dissection before conversion were assessed and used to create new conversion categories. Hospital length of stay (LOS), 30-day complications, operative times and charges, and hospital charges were compared between the new groups. RESULTS: In 91% of conversion cases, the conversion was elective. In 49% of these conversions, the number of ports was fewer than four. According to the new conversion categories, most conversions were performed after minimal or no attempt at dissection. There were no differences in LOS, complications, operating room charges, or hospital charges between categories. Of the six emergent conversions (9%), bleeding and concern about common bile duct (CBD) injury were the main reasons. One CBD injury occurred. CONCLUSIONS: In 49% of the cases, conversion was performed without a genuine attempt at laparoscopic dissection. Considering this new insight into the circumstances of conversion, the authors recommend that surgeons make a genuine effort at a laparoscopic approach, as reflected by placing four ports and trying to elevate the gallbladder before converting a case to an open approach.

Geographies of the global co-editor network in oncology.

The co-editor networks of academic journals are generally examined at the journal level. This paper investigates the geographies of the global co-editor network in oncology through the lens of cities. After using different network methods to analyze the global co-editor network, we found that the network can be characterized by a core-periphery structure. The dense core is occupied by many highly interconnected cities, whereas the periphery contains many cities maintaining loose connections with the core cities. The core shows an asymmetric dual sub-core structure. The greater sub-core is constituted by Northern American cities with New York, Washington DC, Boston, Houston, and Los Angeles in the center, whereas the smaller sub-core is formed by Asian cities and centered on Tokyo, Seoul, Osaka, Beijing, and Shanghai. The European core cities do not form a well-outlined sub-core but produce a ringlike shape around the Northern American core. This structure of the co-editor network is a consequence of the prestige effect still characterizing global science. Many European and Chinese journals tend to employ Northern American editors (US-based editors in the first place) to help increase the reputation of the journal. However, US-based journals are more interested in recruiting American editors from the top-ranked national cancer centers and universities rather than outside of the country.

Allocating vaccines to remote and on-site workers in the tradable sector.

Vaccination may be the solution to the pandemic-induced health crisis, but the allocation of vaccines is a complex task in which ethical, economic and social considerations are important. The biggest challenge is to use the limited number of vaccines available in a way that protects vulnerable groups, prevents further spread of infection, and reduces economic uncertainty. We argue that once the vaccination of healthcare workers and the most vulnerable groups has been completed, prioritizing the vaccination of on-site workers is important not only to slow the spread of the infection, but also to ensure the smooth running of economic production. We propose a simple economic model where remote and on-site workers are complementary to each other in the short run, thus a negative shock to the supply of either one may decrease the demand for the other, leading to unemployment. By illustrating the model using pre-Covid employment data from Sweden and Hungary, we show that the optimal vaccine allocation between remote and on-site workers in the tradable sector should be based on different proportions depending on the relative infection risk of on-site workers and the degree of vaccine availability. As long as the number of vaccines is limited and on-site workers are at higher risk of infection, they should be preferred in general. However, as more vaccines become available, countries like Sweden, where the share of occupations that can be done remotely is higher shall start immunize remote workers. In Hungary, where on-site work is dominant in the tradable sector, continued vaccination of on-site workers is more beneficial.

Initial experiences with the use of covered stents in endovascular treatment of aortoiliac stenoocclusive diseases / Aortoiliacalis stenoocclusiv betegség fedett sztentekkel végzett endovascularis ellátásával szerzett kezdeti tapasztalataink

Introduction: Treatment for complex aortoiliac stenoocclusive disease traditionally is open surgical repair. Endovascular approach is associated with less perioperative stress for the patient, and is a reasonable solution. Covered stent implantation is an alternative treatment option in this patient population even in the case of aortobiiliac or aortobifemoral bypasses. Objective: Assessing outcomes of aortoiliac covered stent implantation at our vascular center. Method: We retrospectively analysed the data of 36 prospectively registered, consecutive patients who underwent aortoiliac covered stent implantations at our department between the 1th November 2019 and 30th September 2021. Medical records, perioperative complications, preoperative and postoperative Rutherford stages and ankle-brachial index were recorded. One-year survival and primary patency as primary endpoints were presented on Kaplan-Meier curve. Our secondary endpoints were change of the ankle-brachial index and Rutherford stage, and the incidence of the major amputation. Results: 36 patients were included in the study. Mean follow-up time was 12 +/- 6.9 months. TASC C-D aortoiliac lesions were the indication of the procedures in 72.2% (n = 26). Patients had critical limb ischaemia in 44% (n = 16). In 64% (n = 23), interventions were performed via percutaneous puncture. In-hospital stay was 5 +/- 7 days. Perioperative bleeding and reoperation occured in 4 (11.1%) and 6 (16.6%) cases, respectively. Perioperative mortality was zero. The one-year survival and primary patency were 94.3% and 91.4%, respectively. The postoperative Rutherford stage (3 [2] vs. 1 [1]; p < 0.001) and ankle-brachial index (0.4 [0.55] vs. 1 [0.4]; p < 0.001) improved significantly compared to the preoperative ones. Unplanned major amputation was not performed. Conclusion: Significant clinical improvement with low perioperative mortality, acceptable morbidity and high one-year primary patency and survival can be obtained by the use of covered stents in the treatment of aortoiliac stenoocclusive disease. This procedure can be an alternative to open surgical repair.

Urban hierarchy and spatial diffusion over the innovation life cycle.

Successful innovations achieve large geographical coverage by spreading across settlements and distances. For decades, spatial diffusion has been argued to take place along the urban hierarchy. Yet, the role of geographical distance was difficult to identify in hierarchical diffusion due to missing data on spreading events. In this paper, we exploit spatial patterns of individual invitations sent from registered users to new users over the entire life cycle of a social media platform. We demonstrate that hierarchical diffusion overlaps with diffusion to close distances and these factors co-evolve over the life cycle. Therefore, we disentangle them in a regression framework that estimates the yearly number of invitations sent between pairs of towns. We confirm that hierarchical diffusion prevails initially across large towns only but emerges in the full spectrum of settlements in the middle of the life cycle when adoption accelerates. Unlike in previous gravity estimations, we find that after an intensifying role of distance in the middle of the life cycle a surprisingly weak distance effect characterizes the last years of diffusion. Our results stress the dominance of urban hierarchy in spatial diffusion and inform future predictions of innovation adoption at local scales.

Understanding European integration with bipartite networks of comparative advantage.

Core objectives of European common market integration are convergence and economic growth, but these are hampered by redundancy, and value chain asymmetries. The challenge is how to harmonize labor division to reach global competitiveness, meanwhile bridging productivity differences across the EU. We develop a bipartite network approach to trace pairwise co-specialization by applying the revealed comparative advantage method within and between the EU15 and Central and Eastern European (CEE). This approach assesses redundancies and the division of labor in the EU at the level of industries and countries. We find significant co-specialization among CEE countries but a diverging specialization between EU15 and CEE. Productivity increases in those CEE industries that have co-specialized with other CEE countries after EU accession, while co-specialization across CEE and EU15 countries is less related to productivity growth. These results show that a division of sectoral specialization can lead to productivity convergence between EU15 and CEE countries.

Understanding hesitancy with revealed preferences across COVID-19 vaccine types.

Many countries have secured larger quantities of COVID-19 vaccines than their population is willing to take. The abundance and the large variety of vaccines created not only an unprecedented intensity of vaccine related public discourse, but also a historical moment to understand vaccine hesitancy better. Yet, the heterogeneity of hesitancy by vaccine types has been neglected in the existing literature so far. We address this problem by analysing the acceptance and the assessment of five vaccine types. We use information collected with a nationally representative survey at the end of the third wave of the COVID-19 pandemic in Hungary. During the vaccination campaign, individuals could reject the assigned vaccine to wait for a more preferred alternative that enables us to quantify revealed preferences across vaccine types. We find that hesitancy is heterogenous by vaccine types and is driven by individuals' trusted source of information. Believers of conspiracy theories are more likely to evaluate the mRNA vaccines (Pfizer and Moderna) unacceptable. Those who follow the advice of politicians are more likely to evaluate vector-based (AstraZeneca and Sputnik) or whole-virus vaccines (Sinopharm) acceptable. We argue that the greater selection of available vaccine types and the free choice of the individual are desirable conditions to increase the vaccination rate in societies.

Evaluation of colonoscopy technical skill levels by use of an objective kinematic-based system.

BACKGROUND: Colonoscopy requires training and experience to ensure accuracy and safety. Currently, no objective, validated process exists to determine when an endoscopist has attained technical competence. Kinematics data describing movements of laparoscopic instruments have been used in surgical skill assessment to define expert surgical technique. We have developed a novel system to record kinematics data during colonoscopy and quantitatively assess colonoscopist performance. OBJECTIVE: To use kinematic analysis of colonoscopy to quantitatively assess endoscopic technical performance. DESIGN: Prospective cohort study. SETTING: Tertiary-care academic medical center. POPULATION: This study involved physicians who perform colonoscopy. INTERVENTION: Application of a kinematics data collection system to colonoscopy evaluation. MAIN OUTCOME MEASUREMENTS: Kinematics data, validated task load assessment instrument, and technical difficulty visual analog scale. RESULTS: All 13 participants completed the colonoscopy to the terminal ileum on the standard colon model. Attending physicians reached the terminal ileum quicker than fellows (median time, 150.19 seconds vs 299.86 seconds; p<.01) with reduced path lengths for all 4 sensors, decreased flex (1.75 m vs 3.14 m; P=.03), smaller tip angulation, reduced absolute roll, and lower curvature of the endoscope. With performance of attending physicians serving as the expert reference standard, the mean kinematic score increased by 19.89 for each decrease in postgraduate year (P<.01). Overall, fellows experienced greater mental, physical, and temporal demand than did attending physicians. LIMITATION: Small cohort size. CONCLUSION: Kinematic data and score calculation appear useful in the evaluation of colonoscopy technical skill levels. The kinematic score appears to consistently vary by year of training. Because this assessment is nonsubjective, it may be an improvement over current methods for determination of competence. Ongoing studies are establishing benchmarks and characteristic profiles of skill groups based on kinematics data.

Universal patterns of long-distance commuting and social assortativity in cities.

Millions commute to work every day in cities and interact with colleagues, partners, friends, and strangers. Commuting facilitates the mixing of people from distant and diverse neighborhoods, but whether this has an imprint on social inclusion or instead, connections remain assortative is less explored. In this paper, we aim to better understand income sorting in social networks inside cities and investigate how commuting distance conditions the online social ties of Twitter users in the 50 largest metropolitan areas of the United States. An above-median commuting distance in cities is linked to more diverse individual networks, moreover, we find that longer commutes are associated with a nearly uniform, moderate reduction of overall social tie assortativity across all cities. This suggests a universal relation between long-distance commutes and the integration of social networks. Our results inform policy that facilitating access across distant neighborhoods can advance the social inclusion of low-income groups.

Long-term analysis of the results of aorto-bifemoral bypass surgery for diffuse aorto-biiliac occlusive disease / Az aortobiiliacalis occlusiv érbetegség miatt végzett aortobifemoralis bypass mutétek hosszú távú eredményeinek elemzése.

Összefoglaló. Bevezetés: A diffúz aortobiiliacalis érszakasz occlusiv betegségének kezelésére alkalmazott aortobifemoralis bypass szerepe csökken az endovascularis mutétek térnyerése miatt. Célkituzés: A vizsgálat célja volt a modern invazív kezelés korszakában a perioperatív és a hosszú távú eredmények elemzése aortobiiliacalis bypass után, melyek összehasonlíthatók az endovascularis megoldások eredményeivel. Módszerek: A retrospektív, egycentrumú vizsgálat során a Semmelweis Egyetem Városmajori Szív- és Érgyógyászati Klinikájának Érsebészeti és Endovaszkuláris Tanszékén 2006. 01. 01. és 2017. 12. 31. között occlusiv aortoiliacalis atherosclerosis miatt primer aortobifemoralis bypass mutéten átesett 419 beteg (átlagéletkor: 62,2 év, SD: ± 8,22; 224 férfi, 53%) adatait elemeztük. Eredmények: A posztoperatív 30 napon belüli mortalitás 5,01%, a késoi mortalitás 10,98% és 29,59% volt 12, illetve 60 hónap után. A betegek 12,57%-ánál történt korai reoperáció, késoi reoperáció 32 (8%) betegnél vált szükségessé. A graft elsodleges nyitva maradása 88,65% és 81,15% volt 12, illetve 60 hónap után. 21 betegnél történt amputáció (6,29%); 57,14%-ban femoralis, 35,71%-ban cruralis szinten, 7,14%-ban a boka szintje alatt. Az amputációkra 35,71%-ban a bypasst követo 30 napon belül, további 35,71%-ban 2 éven belül került sor. Az esetek 35,63%-ában lépett fel egyéb szövodmény; a leggyakoribbak: mutétet igénylo posztoperatív hernia (6,89%), cardiovascularis szövodmény (4,19%), lágyéki nyirokcsorgás vagy sebgyógyulási zavar (4,79%). Következtetés: Eredményeink alapján e betegcsoportban az aortobifemoralis bypass elfogadható, de nem jelentéktelen perioperatív halálozással és magas morbiditással jár. A graft hosszú távú nyitva maradása jó, de az újabb érmutét mind rövid, mind hosszú távon relatíve gyakori. A kevésbé invazív technikák eredményeinek összehasonlítása indokolt a hosszú szakaszú (TASC C, D) elváltozások esetén. Orv Hetil. 2021; 162(3): 99-105. INTRODUCTION: The role of aorto-bifemoral bypass in the treatment of diffuse aorto-biiliac occlusive disease decreases in the era of endovascular surgery. OBJECTIVE: The aim of the study was to analyse the early and long-term postoperative results of aorto-bifemoral bypass in a recent time period. These results may be used as a baseline to compare the results of endovascular procedures. METHODS: In a retrospective, single-center study, the data of 419 patients (mean age: 62.2 years, SD: ± 8.22; 224 men, 53%) who underwent primary aorto-bifemoral bypass due to occlusive aorto-iliac atherosclerosis from 01. 01. 2006 to 31. 12. 2017 at the Department of Vascular and Endovascular Surgery of Semmelweis University Heart and Vascular Center were analysed. RESULTS: Postoperative mortality within 30 days was 5.01%, late mortality was 10.98% and 29.59% after 12 and 60 months, respectively. 12.57% of the patients needed early reoperation and late reoperation was required in 32 cases (8%). The primary graft patency was 88.65% and 81.15% after 12 and 60 months, respectively. 21 patients underwent amputation (6.29%); 57.14% at the femoral level, 35.71% at the crural level and 7.14% below the ankle level. Amputations were performed in 35.71% of the cases within 30 days after the bypass and an additional 35.71% within 2 years. Other complications occurred in 35.63% of the cases; the most common causes were postoperative hernia requiring surgery (6.89%), cardiovascular complication (4.19%) and inguinal wound healing disorders (4.79%). CONCLUSION: Based on our results, aorto-bifemoral bypass surgery is associated with acceptable but not insignificant perioperative mortality and high morbidity in this group of patients. The graft patency is favourable in the long term, however, additional vascular reintervention is common in short and long term as well. Short- and long-term results of percutaneous endovascular techniques in diffuse aorto-biiliac disease (TASC C and D lesions) are suggested to be compared to these recent results of open surgery. Orv Hetil. 2021; 162(3): 99-105.

Inequality is rising where social network segregation interacts with urban topology.

Social networks amplify inequalities by fundamental mechanisms of social tie formation such as homophily and triadic closure. These forces sharpen social segregation, which is reflected in fragmented social network structure. Geographical impediments such as distance and physical or administrative boundaries also reinforce social segregation. Yet, less is known about the joint relationships between social network structure, urban geography, and inequality. In this paper we analyze an online social network and find that the fragmentation of social networks is significantly higher in towns in which residential neighborhoods are divided by physical barriers such as rivers and railroads. Towns in which neighborhoods are relatively distant from the center of town and amenities are spatially concentrated are also more socially segregated. Using a two-stage model, we show that these urban geography features have significant relationships with income inequality via social network fragmentation. In other words, the geographic features of a place can compound economic inequalities via social networks.