The Impact of Seasonality on Prosthetic Arteriovenous Vascular Access Graft Thrombosis

2021 ◽  
Author(s):  
Stefan Zammit ◽  
Kevin Cassar
Keyword(s):  
Relative Humidity ◽  
Vascular Access ◽  
Seasonal Pattern ◽  
Neointimal Hyperplasia ◽  
Clinical Impression ◽  
Arteriovenous Graft ◽  
Venous Outflow ◽  
Graft Thrombosis ◽  
The Impact ◽  
Access Graft

Highlights Abstract Introduction: Arteriovenous prosthetic grafts are susceptible to recurrent thrombotic occlusions mainly due to venous outflow disease secondary to neointimal hyperplasia. Maintenance of vascular access for dialysis is a perpetual challenge for both patients and health care systems. In regions with hotter climates, there is a clinical impression that episodes of prosthetic arteriovenous vascular access graft thrombosis are more frequent during hot dry summers secondary to dehydration and increased blood viscosity. Seasonality of thrombotic events has been observed in multiple vascular beds. However, a seasonal pattern or any association of arteriovenous graft thrombosis with temperature and relative humidity levels has never been fully demonstrated. Methods: Data were collected prospectively from January 2014 until December 2020 but analyzed retrospectively. In this 7-year timeframe, 289 episodes of arteriovenous graft thrombosis were identified from 142 grafts fashioned. Results: No monthly variation (P = 0.35) or seasonal variation (P = 0.91) was identified. No statistically significant correlation between episodes of thrombosis and mean monthly temperature and mean relative humidity was noted. Conclusion: No evidence was identified to support this theory. However, multiple issues with assessments of events must be conceded. Graft thrombosis is multifactorial in nature, and venous outflow disease contributes toward a significant number of these events. Within our local cohort, a low primary patency rate was identified, which further contributes to graft interventions. Relatively small numbers were recruited, and therefore, potential correlations could have been missed.

Hybrid surgical approach in treatment of vascular access graft thrombosis

2020 ◽  
Vol 22 (4) ◽  
pp. 506-513
Author(s):  
I.S. Cherniakov ◽  
◽  
M.S. Vakhitov ◽  
Keyword(s):  
Vascular Access ◽  
Surgical Approach ◽  
Graft Thrombosis ◽  
Access Graft

Hemodynamic impact of VASQ device in vascular access creation

2020 ◽  
pp. 112972982098315
Author(s):  
Roberto Palumbo ◽  
Sara Dominijanni ◽  
Alessia Centi ◽  
Gabriele D’Urso ◽  
Paola Tatangelo ◽  
...  
Keyword(s):  
Arteriovenous Fistula ◽  
Vascular Access ◽  
Complication Rate ◽  
Neointimal Hyperplasia ◽  
Arterial Flow ◽  
Control Group ◽  
Secondary Patency ◽  
Arteriovenous Fistulae ◽  
The Mean ◽  
The Impact

Background: Native arteriovenous fistula is the preferred vascular access in term of functionality, efficiency and complication rate. Nevertheless, research continues to seek strategies to reduce the risk of neointimal hyperplasia and hemodynamic modification. The aim of the study was to evaluate the impact on hemodynamic of the VasQ device in arteriovenous fistulae creation. Methods: The analysis included patients who underwent to fistula creation with or without implantation of the VasQ device between May and September 2019. The hemodynamic parameters were evaluated pre-operatively and at a follow-up of 1, 3, 6 months. The patency and complication rate were evaluated. Results: Fifteen VasQ devices were implanted during 30 arteriovenous fistula surgery. The baseline patients features were similar between groups (VasQ treated/control). At baseline, preoperative arterial flow was similar; radial artery diameter at surgical site was 3.4 ± 0.8 mm in treated and 2.8 ± 0.5 mm in the control group. The mean arterial flow at 1 month was 480 ± 210 mL/min in treated and 561 ± 27 mL/min in the control group. At 3 months the mean arterial flow in treated was 645 ± 143 mL/min versus 824 ± 211 mL/min ( p = 0.02) in the control group; at 6 months the arterial flow was 714 ± 146 mL/min versus 810 ± 194 mL/min ( p = 0.05) in control group. The cardiac output flow at 6 months in the treated group was 4458 ± 928 mL/min versus 5599 ± 1355 mL/min ( p = 0.05) in the control group. At 6 months the primary patency was 73% and 80% and the secondary patency 80% and 86% in treated compared to the control group, respectively. No VASQ device complications were recorded. Conclusion: The analysis of these data suggested that using VasQ device could be protective against the hemodynamic modification that occur during arteriovenous fistulae creation.

The effect of vascular access type on intra-access flow volume during hemodialysis

2019 ◽  
Vol 20 (6) ◽  
pp. 746-751
Author(s):  
Hoon Suk Park ◽  
Woo Jeong Kim ◽  
Joonsung Choi ◽  
Hyung Wook Kim ◽  
Jun Hyun Baik ◽  
...  
Keyword(s):  
Arteriovenous Fistula ◽  
Analysis Of Variance ◽  
Vascular Access ◽  
Repeated Measures ◽  
Arteriovenous Graft ◽  
Flow Volume ◽  
Upper Arm ◽  
Repeated Measures Analysis ◽  
The Impact ◽  
Over Time

Introduction: Previous studies have revealed that vascular access resistance is constant during hemodialysis, but differs according to vascular access type. It is possible that intra-access flow volume (Qac) variation during hemodialysis may also differ according to vascular access type. We conducted this study to investigate whether there are differences in Qac according to vascular access type during hemodialysis. Methods: A total of 58 lower-arm arteriovenous fistula, 14 lower-arm arteriovenous graft, 27 upper-arm arteriovenous fistula, and 45 upper-arm arteriovenous graft cases were studied. Three consecutive Qac values (at 30, 120, and 240 min after the start of hemodialysis) were measured in each patient by the ultrasound dilution technique. Variations in Qac over time were analyzed using repeated measures analysis of variance and multivariate regression analyses, to assess the impact of different factors on Qac variation. Results: The repeated measures analysis of variance revealed that a significant interaction exists between time and vascular access type (p < 0.001). This suggests that vascular access type affects Qac change (%) variation over time during hemodialysis. In a multivariate analysis, mean arterial pressure change during hemodialysis (p = 0.009), access type (p < 0.001), and access location (p < 0.001) were independent variables causing Qac change variation. Conclusion: This study showed that there is a significant difference in Qac variation according to vascular access type during hemodialysis and that arteriovenous graft (vs arteriovenous fistula) and the lower-arm location (vs upper arm) were associated with a decrease in Qac during hemodialysis. This suggests that consideration of vascular access type is required to minimize Qac variation during hemodialysis.

scholarly journals Vascular access graft thrombosis by iatrogenic fistula

2010 ◽  
Vol 39 (5) ◽  
pp. 214-215 ◽  
Author(s):  
Jeong Kye Hwang ◽  
In Sung Moon ◽  
Ji Il Kim
Keyword(s):  
Vascular Access ◽  
Graft Thrombosis ◽  
Access Graft

Endothelial Nitric Oxide Synthase Gene Intron 4 (VNTR) Polymorphism and Vascular Access Graft Thrombosis

2007 ◽  
Vol 20 (1) ◽  
pp. 49-53 ◽  
Author(s):  
Ozgur Basaran ◽  
F. Belgin Atac ◽  
Feza Karakayali ◽  
Ibrahim Aliosmanoglu ◽  
Mahmut Can Yagmurdur ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Vascular Access ◽  
Endothelial Nitric Oxide Synthase ◽  
Graft Thrombosis ◽  
Vntr Polymorphism ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide ◽  
Intron 4 ◽  
Access Graft

Impact of an educative program on dialysis patients’ knowledge and mental health: controlled before and after program

2018 ◽  
Vol 10 (2) ◽  
pp. 20204
Author(s):  
Laetitia Idier ◽  
Aurélie Untas ◽  
Nicole Rascle ◽  
Michèle Koleck ◽  
Maider Aguirrezabal ◽  
...  
Keyword(s):  
Mental Health ◽  
Depressive Symptoms ◽  
Vascular Access ◽  
Educational Program ◽  
Psychological State ◽  
Control Group ◽  
Dialysis Patients ◽  
Emotional Change ◽  
The Impact ◽  
Experimental Group

Introduction:Psychological impact of Therapeutic Patient Education (TPE) for dialysis patients is rarely evaluated since the focus of many studies is on medical variables (i.e., adherence).Objectives:The aims of this study were: 1) to estimate the impact of a TPE program on knowledge, depression and anxiety, 2) to examine change in knowledge as a mediator of the effects of a TPE program on mental health.Method:This study was conducted in three hemodialysis units and comprised two groups: an experimental group with education and a control group with routine care. The program was based of 5 educative sessions. Knowledge, depressive and anxious symptoms were assessed with self-reported outcomes measured before and 3 months after the program.Results:The sample comprised 125 patients. Knowledge about vascular access and nutrition (p < 0.01) and depressive symptoms increased in the experimental group (p < 0.01). Analysis of mediation showed that changes in knowledge about vascular access were a significant mediator of the effects of the program on depressive symptoms (F = 4.90;p = 0.01).Discussion:Knowledge acquired during an educational program could lead to an emotional change. Improving knowledge often leads to an awareness of the risks that can modify the psychological state of patients by reminding them of their vulnerability. This study shows that it is required to be attentive to the way of transmitting knowledge. It’s necessary adapting this transmission to the needs of patients and promoting the acquisition of psychosocial competence too.Conclusion:This study shows that knowledge acquired during an educational program can lead to an emotional change in the short term. A long-term follow-up of the population should be interesting to observe these emotional effects.

scholarly journals Seasonality of Non-SARS, Non-MERS Coronaviruses and the Impact of Meteorological Factors

Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 187
Author(s):  
Olympia E. Anastasiou ◽  
Anika Hüsing ◽  
Johannes Korth ◽  
Fotis Theodoropoulos ◽  
Christian Taube ◽  
...  
Keyword(s):  
Logistic Regression ◽  
Relative Humidity ◽  
Cloud Cover ◽  
Detection Rate ◽  
Logistic Regression Model ◽  
Meteorological Factors ◽  
Seasonal Pattern ◽  
Weather Factors ◽  
Immunosuppressed Patients ◽  
Immunocompetent Patients

Background: Seasonality is a characteristic of some respiratory viruses. The aim of our study was to evaluate the seasonality and the potential effects of different meteorological factors on the detection rate of the non-SARS coronavirus detection by PCR. Methods: We performed a retrospective analysis of 12,763 respiratory tract sample results (288 positive and 12,475 negative) for non-SARS, non-MERS coronaviruses (NL63, 229E, OC43, HKU1). The effect of seven single weather factors on the coronavirus detection rate was fitted in a logistic regression model with and without adjusting for other weather factors. Results: Coronavirus infections followed a seasonal pattern peaking from December to March and plunged from July to September. The seasonal effect was less pronounced in immunosuppressed patients compared to immunocompetent patients. Different automatic variable selection processes agreed on selecting the predictors temperature, relative humidity, cloud cover and precipitation as remaining predictors in the multivariable logistic regression model, including all weather factors, with low ambient temperature, low relative humidity, high cloud cover and high precipitation being linked to increased coronavirus detection rates. Conclusions: Coronavirus infections followed a seasonal pattern, which was more pronounced in immunocompetent patients compared to immunosuppressed patients. Several meteorological factors were associated with the coronavirus detection rate. However, when mutually adjusting for all weather factors, only temperature, relative humidity, precipitation and cloud cover contributed independently to predicting the coronavirus detection rate.

scholarly journals Impact of temperature and relative humidity on the transmission of COVID-19: a modelling study in China and the United States

BMJ Open ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. e043863
Author(s):  
Jingyuan Wang ◽  
Ke Tang ◽  
Kai Feng ◽  
Xin Lin ◽  
Weifeng Lv ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Relative Humidity ◽  
Human Mobility ◽  
The United States ◽  
Reproductive Number ◽  
Cross Sectional ◽  
The Usa ◽  
Higher Temperature ◽  
Potential Impact ◽  
The Impact

ObjectivesWe aim to assess the impact of temperature and relative humidity on the transmission of COVID-19 across communities after accounting for community-level factors such as demographics, socioeconomic status and human mobility status.DesignA retrospective cross-sectional regression analysis via the Fama-MacBeth procedure is adopted.SettingWe use the data for COVID-19 daily symptom-onset cases for 100 Chinese cities and COVID-19 daily confirmed cases for 1005 US counties.ParticipantsA total of 69 498 cases in China and 740 843 cases in the USA are used for calculating the effective reproductive numbers.Primary outcome measuresRegression analysis of the impact of temperature and relative humidity on the effective reproductive number (R value).ResultsStatistically significant negative correlations are found between temperature/relative humidity and the effective reproductive number (R value) in both China and the USA.ConclusionsHigher temperature and higher relative humidity potentially suppress the transmission of COVID-19. Specifically, an increase in temperature by 1°C is associated with a reduction in the R value of COVID-19 by 0.026 (95% CI (−0.0395 to −0.0125)) in China and by 0.020 (95% CI (−0.0311 to −0.0096)) in the USA; an increase in relative humidity by 1% is associated with a reduction in the R value by 0.0076 (95% CI (−0.0108 to −0.0045)) in China and by 0.0080 (95% CI (−0.0150 to −0.0010)) in the USA. Therefore, the potential impact of temperature/relative humidity on the effective reproductive number alone is not strong enough to stop the pandemic.

scholarly journals Role of Doppler ultrasonography in the evaluation of hemodialysis arteriovenous access maturation and influencing factors

2021 ◽  
pp. 112972982096506
Author(s):  
Eva Chytilova ◽  
Tamara Jemcov ◽  
Jan Malik ◽  
Jernej Pajek ◽  
Branko Fila ◽  
...  
Keyword(s):  
Vascular Access ◽  
Doppler Ultrasonography ◽  
Arteriovenous Graft ◽  
Central Venous ◽  
Preoperative Mapping ◽  
High Incidence ◽  
Arteriovenous Access ◽  
Ultrasound Parameters ◽  
Fistula Maturation

The goal of vascular access creation is to achieve a functioning arteriovenous fistula (AVF) or arteriovenous graft (AVG). An autologous fistula has been shown to be superior to AVG or to central venous catheters (CVCs) with lowest rate of re-intervention, but vessel obstruction or immaturity accounts for 20 % to 54% of cases with primary failure of AVF. This review is focused on the factors influencing maturation; indication and timing of preoperative mapping/creation of vascular access; ultrasound parameters for creation AVF/AVG; early postoperative complications following creation of a vascular access; ultrasound determinants of fistula maturation and endovascular intervention in vascular access with maturation failure. However, vascular accesses that fail to develop, have a high incidence of correctable abnormalities, and these need to be promptly recognized by ultrasonography and managed effectively if a high success rate is to be expected. We review approaches to promoting fistula maturation and duplex ultrasonography (DUS) of evaluating vascular access maturation.

scholarly journals Evolution of the viscoelastic properties of painting stratigraphies: a moisture weathering and nanoindentation approach

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Mathilde Tiennot ◽  
Davide Iannuzzi ◽  
Erma Hermens
Keyword(s):  
Mechanical Properties ◽  
Relative Humidity ◽  
Cultural Heritage ◽  
Mechanical Behaviour ◽  
Viscoelastic Properties ◽  
Viscoelastic Behaviour ◽  
Storage And Loss Moduli ◽  
Heritage Studies ◽  
Paint Films ◽  
The Impact

AbstractIn this investigation on the mechanical behaviour of paint films, we use a new ferrule-top nanoindentation protocol developed for cultural heritage studies to examine the impact of repeated relative humidity variations on the viscoelastic behaviour of paint films and their mechanical properties in different paint stratigraphies through the changes in their storage and loss moduli. We show that the moisture weathering impact on the micromechanics varies for each of these pigment-oil systems. Data from the nanoindentation protocol provide new insights into the evolution of the viscoelastic properties dsue to the impact of moisture weathering on paint films.

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