Arteriovenous Fistula In Patients Research Articles

Arteriovenous fistula, pulmonary hypertension, and tricuspid dysfunction in renal transplant recipients. A possible solution

Introduction: Cardiovascular dysfunction is the first cause of death in patients with chronic kidney disease. Methods: Observational, longitudinal and prospective study, which included 58 patients with functioning renal transplant who were studied different echocardiographic variables, before and six months after the closure of the arteriovenous fistula. Results: The average age was 46.62 years and the most frequent was male 30 (51.72%). The flow of angioaccesses at the wrist level was demonstrated in 28 patients (45.9%) with evidence of regression of mean pulmonary artery pressure from 25.56 to 19.58 mmHg (p=0.002), more connoted for those of intermediate flow; 14. Also, the area of tricuspid insufficiency was greater for that group; from 3.15 to 1.96 cm2 (p=0.001). The pattern of mild dysfunction was observed in 38 patients (62.3%) prior to closure. Subsequent to this 27; (51.9%), exhibited minimal valvular insufficiency and 9 individuals (14.9%) did not show any degree of valvular dysfunction. Conclusions: Closure of the arteriovenous fistula in patients with functioning renal transplantation contributed to decrease the risk of pulmonary hypertension and progression of tricuspid valve dysfunction.

Improved AV Fistula Usability with Fewer Interventions Leads to Reduced Annualized Cost of AV Fistula Patients: A Propensity Score-Matched Comparative Prospective Study

A vascular external support for arteriovenous fistula (AVF) creation (VasQ, Laminate Medical, Tel Aviv, Israel) has improved functional success in multiple European studies. Herein is the first complete report of the U.S. Pivotal Comparative Study results with a cost analysis is presented for VasQ over a 24-month period. The U.S. Pivotal study prospectively enrolled 144 patients (90% brachiocephalic and 10% radiocephalic) at 15 sites. A group of 782 patients treated by the same surgeons from the study immediately prior to the VasQ trial enrollment period was developed from the Medicare claims database as a comparative group. Demographic, procedural and postprocedural data were collected for up to 24 months after surgery. To emulate randomized studies, a propensity score weighting method (inverse probability treatment weighting using average treatment effect) was applied to the claims data. Statistical comparisons of primary patency (freedom from intervention), functional success (continuous use for dialysis over a minimum of 30 days), and post-creation intervention rates were made against the matched comparator group as well as calculating payer cost. Descriptive comparisons were made for primary failure rate (abandonment before first use by 6-month follow-up) and 24-month cumulative patency (freedom from abandonment) rates against published meta-analyses. The median diameter of vessels at the VasQ AVF creation site was 4.25 mm (range, 2.0-6.6 mm) arterial and 3.95 mm (range, 2.3-7.8 mm) venous. Incidence of steal (4.2%), infection (0.7%), and (pseudo)aneurysm (0.7%) at 24 months compared favorably with standard AVF creations. Demographic data for the VasQ and Medicare control groups before and after weighting were typical of a U.S. population (Table I). VasQ AVFs demonstrated superior primary patency, functional success and intervention rates compared against the matched cohort (Table II). Primary failure of 7.9% for VasQ AVF patients compared favorably to the 22.0% to 32.2% reported in contemporary U.S. meta-analyses. Cumulative patency of 76.7% (95% confidence interval, 67.7%-83.4%) at 24 months for VasQ was superior to contemporary meta-analyses reporting 53.7% to 63.0% for standard AVFs. No difference in cumulative patency was observed between patients requiring interventions and those that did not, demonstrating VasQ did not inhibit the ability of physicians to maintain patency. The nearly 50% reduction in access interventions with VasQ at 6 months resulted in an annualized cost reduction of $7764.19 per patient-year. The VasQ vascular external support device delivered more functional fistula success, with earlier usability and fewer interventions, reducing overall costs of fistula creation.Table IMatched demographicsCharacteristicsVasQUnmatched controlUnmatched SMDMatched controlMatched SMDMale61.1% (88/144)56.3% (440/782)9.964.9%−7.9Black35.4% (51/144)47.4% (364/768)−24.531.5%8.3White53.5% (77/144)43.1% (331/768)20.957.9%−9.0Other11.1% (16/144)9.5% (73/768)5.310.6%1.8Mean age58.9 ± 11.460.8 ± 12.7−15.758.7 ± 5.63.0Obesity52.1% (75/144)51.2% (400/782)1.948.3%7.6Active dialysis66.0% (95/144)65.3% (511/782)1.365.7%0.6Diabetic69.4% (100/144)79.0% (618/782)−22.069.4%0.1Congestive heart failure21.5% (31/144)41.6% (325/782)−44.122.8%−3.0SMD, Standard mean difference.Values are (proportion) and [range]. Boldface entries indicate statistical significance. Open table in a new tab Table IIVasQ patient outcomes relative to a matched Medicare comparatorEndpoint (n)VasQ vs controlOdds ratioMatched P valuePrimary patency at 6 months64.2% vs 35.5%3.27[2.15-5.17]<.0001Continuous AVF use at 3 months43.4% vs 26.7%2.15[1.32-4.47].0069Continuous AVF use at 6 months72.5% vs 56.3%2.05[1.23-3.75].0059Intervention rate at 6 months0.97 vs 1.91NA<.0001Values are 95% confidence intervals. Boldface entries indicate statistical significance. Open table in a new tab

Brachiocephalic and Radiocephalic Arteriovenous Fistulas in Patients with Tunneled Dialysis Catheters Have Similar Outcomes

Patients with tunneled dialysis catheters (TDCs) have a time-sensitive need for afunctional permanent access due to high risk of catheter-associated morbidity. Brachiocephalic arteriovenous fistulas (BCF) have been reported to have higher maturation and patency compared to radiocephalic arteriovenous fistulas (RCF), although more distal creation is encouraged when possible. However, this may lead to a delay in establishing permanent vascular access and, ultimately, TDC removal. Our goal was to assess short-term outcomes after BCF and RCF creation for patients with concurrent TDCs to see if these patients would potentially benefit more from an initial brachiocephalic access to minimize TDC dependence. The Vascular Quality Initiative hemodialysis registry was analyzed from 2011 to2018. Patient demographics, comorbidities, access type, and short-term outcomes including occlusion, reinterventions, and access being used for dialysis, were assessed. There were 2,359 patients with TDC, of whom 1,389 (58.9%) underwent BCF creation and 970 (41.1%) underwent RCF creation. Average patient age was 59years, and 62.8% were male. Compared with RCF, those with BCF were more often older, of female sex, obese, nonindependently ambulatory, have commercial insurance, diabetes, coronary artery disease, chronic obstructive pulmonary disease, be on anticoagulation, and have a cephalic vein diameter of ≥3mm (all P<0.05). Kaplan-Meier analysis for 1-year outcomes for BCF and RCF, respectively, showed that primary patency was 45% vs. 41.3% (P=0.88), primary assisted patency was 86.7% vs. 86.9% (P=0.64), freedom from reintervention was 51.1% vs. 46.3% (P=0.44), and survival was 81.3% vs. 84.9% (P=0.02). Multivariable analysis showed that BCF was comparable to RCF with respect to primary patency loss (hazard ratio [HR] 1.11, 95% confidence interval [CI] 0.91-1.36, P=0.316), primary assisted patency loss (HR 1.11, 95% CI 0.72-1.29, P=0.66), and reintervention (HR 1.01, 95% CI 0.81-1.27, P=0.92). Access being used at 3months was similar but trending towards RCF being used more often (odds ratio 0.7, 95% CI 0.49-1, P=0.05). BCFs do not have superior fistula maturation and patency compared to RCFs in patients with concurrent TDCs. Creation of radial access, when possible, does not prolong TDC dependence.

Development of hemodynamically relevant acquired arterio-venous fistulae in patients with venous malformations.

Venous malformations tend to retain their slow-flow behavior, even in progressive disease or regression following therapy. The aim of this study is to analyze the development of acquired hemodynamic relevant arterio-venous fistulae in patients with slow-flow malformations. This study is a retrospective analysis based on a consecutive local registry at a tertiary care Interdisciplinary Center for Vascular Anomalies. Patients with venous malformations and development of secondary arterio-venous fistulae were included. Indications for therapy of the vascular malformation were based on patients' symptoms and complications. The following endpoints were of clinical interest and were assessed: origin of development of arteriovenous fistula, development of secondary comorbidities as a result of the vascular malformation. For analysis we focused on descriptive statistics. Out of 1213 consecutive patients with vascular malformations, in 6 patients perfusion changed from slow flow to arterio-venous fast-flow patterns. Four patients developed the fistula after local trauma in the area of the malformation, the other 2 patients developed the fistula due to progression of the disease and recurrent thrombophlebitis. These 2 patients had no trauma or interventions at the time of arterio-venous fistula development. Acquired arterio-venous fast-flow fistula in patients with slow flow vascular malformation is very rare and might be a result of local trauma or the progression of the disease with recurrent thrombophlebitis. Specific evidence-based treatment options for these patients do not exist.

Long-term arteriovenous fistula prognosis for maintenance hemodialysis patients who accepted PIRRT by using arteriovenous fistula.

Maintenance hemodialysis (MHD) patients are often admitted to the hospital for severe morbidities. Prolonged intermittent renal replacement therapy (PIRRT) is required during the hospital staying. There are controversial opinions on the use of arteriovenous fistula (AVF) as vascular access for PIRRT in MHD patients. Patients with AVF who accepted PIRRT in our center between January 2014 and June 2021 were retrospectively screened. AVF dysfunction and patient mortality were assessed as endpoints. Univariate and multivariate regression models were employed to identify the risk factors of AVF dysfunction. About 162 patients were included in our present study. Twenty-six experienced AVF dysfunction, of whom 53.8%, 19.2%, and 27.0% had percutaneous transluminal balloon angioplasty, surgical revision, and AVF reconstruction, respectively. The accumulated AVF dysfunction rates were 11.8%, 16.2%, and 21.0% in 1, 2, and 3 years, respectively. Multivariate analysis revealed that smoking (HR 2.750, 95% CI 1.181-6.402, p = 0.019), higher platelet (PLT, HR 1.009, 95% CI 1.000-1.017, p = 0.047), higher prothrombin activity (PTA, HR 1.039, 95% CI 1.012-1.066, p = 0.004), and lower diastolic blood pressure (DBP, HR 0.963, 95% CI 0.932-0.996, p = 0.026) were independent risk factors for AVF dysfunction. During the follow-up period, 37 patients died. Overall, the use of AVF for PIRRT might not dramatically increase the incidence of AVF dysfunction. And, Smoking, lower DBP, higher PLT, and higher PTA were associated with increased AVF dysfunction.

End Stage Renal Disease: AVF for Hemodialysys: Clinical Assessment with/without Ultrasound Doppler, Complications and Failure

Objective/Background: The objective of this study was to study the complications and failure rate after creating an arteriovenous fistula in patients suffering from end-stage renal disease (chronic renal failure). It was also intended to study the importance of preoperative Clinical assessment/physical examination of the patient; and if the vessels for anastomosis appeared to be of a doubtful size, then a doppler study was done to ensure that the vein is of adequate size for creation of a good fistula. Method: In this study 121 cases of end-stage renal disease (chronic renal failure) who needed vascular access for hemodialysis were taken. Ultrasound Doppler study was conducted in those patients whose vessels (for anastomosis) appeared to be of small size on Clinical examination. In the study, the arteriovenous fistulae were created under local anesthesia observing all aseptic precautions. Results: Most commonly, the difficulty encountered during surgery was when the caliber of the vein was small i.e. less than 2.5 mm. An arteriovenous fistula was created only when the size of the vein was at least 2.0 mm. When the size of the vein was small, then a longitudinal incision was given in the vein or Cheatlemanouvre was undertaken to perform the anastomosis. In 4 of the 121 cases when radiocephalic fistula was attempted, we had to convert to brachio-cephalic. No major complication was encountered during the surgery or post-operatively. Some patients (five) had redness and inflammation. Inflammation and redness subsided with antibiotics and it resulted in satisfactory recovery. The fistulas started well showing good thrill. After 30 days, 106 out of 121 AV fistulas created were functioning very well with a patency rate of 87.6%. Conclusion: There was no major complication after creating an arteriovenous fistula. It is important to do a thorough physical examination before surgery so that the vessel is assessed. In doubtful cases, an ultrasound doppler study should be done to know the size and patency of the vessel. We should also take relevant history especially of hypertension, diabetes, i/v canulation, etc.

Systematic review and meta-analysis of preoperative interventions to support the maturation of arteriovenous fistulae in patients with advanced kidney disease.

There is great potential to improve outcomes of arteriovenous fistulas (AVFs) by focusing more on the preoperative period of AVF creation. We aim to systematically review the evidence on safety and efficacy of various preoperative interventions that have been tried to improve AVF maturation and success rate. We searched five databases: PubMed, Embase, CINAHL, Cochrane Library and King's Fund Library. Experimental studies that investigated the effect of various preoperative interventions to improve AVF outcomes among advanced chronic kidney disease (CKD) patients were searched. The effect size for primary outcome was calculated as the weighted mean difference in the final vessel calibre, rate of AVF maturation or primary failure between the intervention and control arm. We also assessed adverse effects and dropout rates. This review was preregistered in the International Prospective Register of Systematic Reviews (CRD42020193257). Eight eligible studies were identified involving three types of intervention: hand exercise (n=6), cholecalciferol supplementation (n=1) and pneumatic compression of the arm using a Fist Assist device (n=1). The overall effect size of hand exercise on distal cephalic vein calibre was 0.24mm [95% confidence interval (CI) 0.03-0.45] on meta-analysis of hand exercise studies. On restricting analysis to two randomized controlled trials (RCTs) that had independent control groups, the effect size was higher, at 0.29mm (95% CI 0.11-0.47). Hand exercise was a well-tolerated intervention, especially when confined to the first 4weeks. Hand exercise is the predominant intervention tried in the preoperative period of AVF creation, although there is methodological heterogeneity. Intermittent pneumatic compression using a Fist Assist device is a novel intervention that has shown some promise. Well-designed prospective RCTs are needed on preoperative interventions among advanced CKD patients, aimed at improving AVF outcomes.

A deep learning algorithm to quantify AVF stenosis and predict 6-month primary patency: a pilot study.

A deep convolutional neural network (DCNN) model that predicts the degree of arteriovenous fistula (AVF) stenosis and 6-month primary patency (PP) based on AVF shunt sounds was developed, and was compared with various machine learning (ML) models trained on patients' clinical data. Forty dysfunctional AVF patients were recruited prospectively, and AVF shunt sounds were recorded before and after percutaneous transluminal angioplasty using a wireless stethoscope. The audio files were converted to melspectrograms to predict the degree of AVF stenosis and 6-month PP. The diagnostic performance of the melspectrogram-based DCNN model (ResNet50) was compared with that of other ML models [i.e. logistic regression (LR), decision tree (DT) and support vector machine (SVM)], as well as the DCNN model (ResNet50) trained on patients' clinical data. Melspectrograms qualitatively reflected the degree of AVF stenosis by exhibiting a greater amplitude at mid-to-high frequency in the systolic phase with a more severe degree of stenosis, corresponding to a high-pitched bruit. The proposed melspectrogram-based DCNN model successfully predicted the degree of AVF stenosis. In predicting the 6-month PP, the area under the receiver operating characteristic curve of the melspectrogram-based DCNN model (ResNet50) (≥0.870) outperformed that of various ML models based on clinical data (LR, 0.783; DT, 0.766; SVM, 0.733) and that of the spiral-matrix DCNN model (0.828). The proposed melspectrogram-based DCNN model successfully predicted the degree of AVF stenosis and outperformed ML-based clinical models in predicting 6-month PP.

Risk Factors of Arteriovenous Fistula Stenosis of Patients with Maintenance Hemodialysis.

To investigate the risk factors of arteriovenous fistula stenosis in maintenance hemodialysis patients. A total of 80 patients with maintenance hemodialysis in our hospital from January 2017 to January 2022 were included. According to the stenosis degree of the arteriovenous fistula, patients were divided into a stenosis group (n = 35) and an unobstructed group (n = 45). Laboratory examination data, such as the demographic characteristics of patients, past medical history, the use of traditional Chinese medicine (TCM), the TCM for improving blood circulation to promote blood circulation and remove blood stasis, and cellular immune function, were collected. Multivariate Logistic regression analysis was used to analyze the influencing factors. There was no significant difference in the age, sexuality, body mass index, proportion of patients with coronary heart disease, cephalic vein diameter, radial artery diameter, albumin, fibrinogen, and blood calcium levels between the two groups (P > 0.05). Compared with the unobstructed group, the stenosis group had higher rates of diabetes and hypertension as well as significantly higher levels of platelets, parathyroid hormone, and D-dimer (P < 0.05). The proportion of TCM application in the stenosis group was 28.6% (10/35), which was significantly lower than that in the unobstructed group 57.8% (26/45). The difference was statistically significant (χ 2 = 6.785, P=0.009). The levels of CD3+ (37.5 ± 5.1% vs. 42.0 ± 4.8%), CD4+ (35.7 ± 3.2% vs. 39.6 ± 3.1%) and CD4+/CD8+ (1.4 ± 0.3 vs. 2.4 ± 1.0) in the stenosis group were significantly lower, while CD8+ level was significantly higher (26.8 ± 5.1% vs. 18.5 ± 6.2%) than that in the unobstructed group (P < 0.001). Logistic regression analysis indicated that the usage of TCM was an independent risk factor for arteriovenous fistula stenosis after adjustment for other factors (odds ratio [OR] 0.302; 95% confidence interval [95% CI] 0.100-0.896; P=0.039). Less use of traditional Chinese medicine for activating blood circulation and removing blood stasis and poor cellular immune function are important factors affecting the function of the arteriovenous fistula in patients with maintenance hemodialysis, which is worthy of clinical attention.

Patency rate difference of the arteriovenous fistula with and without pre-anastomosis balloon dilatation in chronic kidney disease patients

Background: Arteriovenous fistula (AVF) failure rate in chronic kidney disease patients is relatively high due to inadequate feeding arteries and draining veins. The primary balloon angioplasty (PBA) dilatation technique is a way to mitigate AVF failure. There have not been many studies to determine the patency rate with and without PBA. This study analyzed the patency rate and the number of patency failures in Indonesia AVF patients with and without PBA. Methods: A retrospective cohort study was conducted in AVF surgery patients from 2019 to 2021 with or without PBA with a total sample technique. The patient was choosen without AVF surgery in the same arm with had follow-up every three months for three years. We excluded incomplete medical record data and unfollowed patients six weeks after surgery. The Kaplan–Meier method used the log-rank test to estimate each group's patency rate. The p-value&lt;0.05 was considered significant. Results: There were 60 subjects, of which 29 were with PBA and 31 were without PBA. There was a significant difference between the two groups regarding venous diameter and postoperative venous flow volume (p&lt;0.01). The log-rank test showed a significant difference in patency failure in the group without PBA (35.5%, mean patency rate 56.3 weeks) compared to the group with PBA (10.3%, mean patency rate 104.4 weeks) with p=0.028. The median duration showed that 50% of the group without PBA experienced patency failure at week 59.3. In contrast, until the observation's end, the PBA group experienced patency failure of less than 50%. Conclusion: Using the PBA technique can reduce the incidence of patency failure and maintain longer patency in patients with AVF.

Effect of primary balloon angioplasty on draining vein diameter and volume flow in patients with arteriovenous fistula: A cohort study

BackgroundChronic kidney disease (CKD) and end-stage kidney disease (ESKD) cause major morbidity and mortality in 10% of the global population with CKD. The most common renal replacement therapy is hemodialysis with arteriovenous fistula (AVF) access. AVF often undergoes maturation failure due to feeding artery and draining vein inadequacy. Mechanical dilatation, such as primary balloon angioplasty (PBA), can overcome AVF maturation failure. The volume flow (VF) and diameter of the draining veins in AVF patients must be known to evaluate the effect of PBA on AVF maturation. This study aims to analyze the impact of PBA on VF and draining vein diameter in ESKD patients undergoing AVF surgery. MethodsA retrospective cohort clinical trial was conducted at our institution. A total of 75 participants had AVF with an arterial diameter >1.5 mm or vein diameter at the AVF creation site of 2–4 mm. The subjects were divided into 2 groups: the intervention group undergoing PBA (n = 36) and the control group, without PBA (n = 39). PBA was performed using a Mustang ballon (3–6 mm, Medtronic). Follow-ups were conducted at 1 week, 2 weeks, and 6 weeks after AVF creation. ResultsBased on the data, the diameter and VF of the draining veins were significantly larger in the intervention group than in the control group (p < 0.001). Furthermore, we found significant differences in the mean diameter and VF of the draining veins between the control and intervention groups at all stages of examination, from preoperatively to 6 weeks postoperatively (p < 0.001). The strength of the analysis was more than 80%. ConclusionPBA can increase the diameter and VF of the draining veins in patients with AVF.

Far-Infrared Therapy Improves Arteriovenous Fistula Patency and Decreases Plasma Asymmetric Dimethylarginine in Patients with Advanced Diabetic Kidney Disease: A Prospective Randomized Controlled Trial.

Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide synthase and plays a significant role in the pathogenesis of arteriovenous fistula (AVF) dysfunction. The aim of this study is to evaluate the effect of far-infrared (FIR) therapy on the maturation and patency of newly-created AVFs in patients with advanced diabetic kidney disease (DKD) as well as the concurrent change in plasma ADMA. The study enrolled 144 participants with advanced DKD where 101 patients were randomly allocated to the FIR therapy group (N = 50) and control group (N = 51). Patients receiving FIR therapy had a decreased AVF failure rate within 12 months (16% versus 35.3%; p = 0.027); decreased incremental change of ADMA concentration at the 3rd and 12th month; increased AVF blood flow at the 1st, 3rd, and 12th month; increased 3-month physiologic maturation rate (88% versus 68.6%; p = 0.034); increased 1-year unassisted AVF patency rate (84% versus 64.7%; p = 0.017); and increased clinical AVF maturation rate within 12 months (84% versus 62.7%; p = 0.029) compared to the control group. The study demonstrates that FIR therapy can reduce the incremental changes in plasma ADMA concentration, which may be associated with the improvement of AVF prognosis in patients with advanced DKD.

Unravelling the role of MPV/platelets count on vascular access function among haemodialysis Egyptian patients

Background and Aims: End-stage kidney disease (ESKD) is a global health problem. It necessitates renal replacement therapy via renal transplantation, peritoneal dialysis, or hemodialysis. Vascular access is mandatory for every patient maintained on hemodialysis. It is a prerequisite for adequate hemodialysis (HD). Platelets play the most important role in securing vascular access function. Patients and Methods: A retrospective cohort study was conducted on 87 patients who underwent intermittent HD via arteriovenous fistula (AVF). Patients were divided into two groups. Group1 (Study group): patients with recent thrombosed AVF within a week of laboratory investigation. Group2 (Control group): patients with well-functioning AVF Evaluation of patients: Results: The mean platelet volume (MPV), Plateletcrit (PCT), and platelet diameter width (PDW) were 10.43, 0.222, and 13.56 in the study group respectively while in the control group they were 10.11067, 0.201944 and 12.9. MPV/PL count was significant between the two groups. Conclusion: The study found that the larger the platelet indices, the more vascular access malfunctions. The MPV/PL ratio can be used to examine the function of vascular access and estimate its lifespan that continuous monitoring of that ratio might be effective in detecting the risk of AVF in patients receiving regular hemodialysis.

MO792: Validation and Applicability of an Innovative Monitoring System for Vascular Access in Haemodialysis—A Multicentre Study

Abstract BACKGROUND AND AIMS Routine systems for monitoring vascular access (VA) performance are lacking. We recently showed that with a VA triage system it is possible to improve the average value of a number of HD efficiency parameters and that the triage score was associated with clinical outcomes [1]. The triage categorization is generated monthly by a scoring system which is based on a number of parameters (blood flows, VA pressure values, end HD circuit clots and a dedicated score of the external VA examination) recorded at each session by the staff and by the KT/V value recorded once every month. According to threshold values, each VA is classified as Green (G), Yellow (Y) or Red (R), thus attracting the attention of the staff. In our open-label single centre study, with 3 years of follow-up, the average VA scores improved significantly and G VA associated with lower mortality, compared to the Y and R VA. To validate our triage system with a multicentre, blinded approach in a large number of patients. The primary outcome was to evaluate if the triage identifies VA with an increased rate of complications; the secondary outcome was to verify the association of G VA score with better clinical outcomes. METHOD In this interventional prospective multicentre study, each centre used the electronic spreadsheet without knowledge of the generated score and triage. After 6 months of system implementation, 2 years of follow-up (1 January 2020–1 December 2021) were planned to record VA-related events. Two external reviewers evaluated the records. A minimum of 3 months VA follow-up was necessary for patients’ enrolment. RESULTS From 18 HD centres we enrolled 757 patients, aged 64.5 ± 15.5 years; x/y M/F; 27% diabetics; HD since 24.4 ± 32.4 months; 369 (48.7%) with arteriovenous fistula (AVF) and 388 (51.3%) with permanent central venous catheter (CVC). During 11.4 ± 5.6 months of follow-up (range 3–23), 108 537 HD sessions were recorded on the triage electronic spreadsheet, with 214 total clinical events and an event-free time of 224.5 ± 172 days (range 4–713). The VA-related events were 150 (70.1%) with an event-free time of 230 ± 160 days (range 11–713). As of today, we have the association of VA triage with VA events in a subgroup of 300 patients (66.1 ± 11.7 years; HD vintage 28 ± 18; diabetes 27.6%; 180 with AVF and 120 had CVC) who are not different from the remaining 457. In this subgroup, 54% had G VA triage, 39% Y and 7% R. In the subgroups distinguished by VA type, AVF cases (64.5 ± 12.1 years; HD since 30.3 ± 27.2; 24.4% diabetics) were triaged as G in 54%, Y in 41% and R in 5%, while CVC cases (66.5 ± 11.7 years; HD since 28.8 ± 36.5 months; 34.3% diabetics) were G in 54%, Y in 34% and R in 11%. 83 patients had VA-related events VA during 16.3 ± 2.2 months of follow-up (range 3–23), with an event-free time of 237.8 ± 195.9 days. Figure 1 shows how both AVF and CVC patients, stratified into only two triage groups (G versus Y and R together) according to their average triage, had significantly different time-free from events, which was higher in both populations (AVF P = 0.04; CVC P = 0.001) in the green triage groups. CONCLUSION Our VA triage system identifies 40% of vascular accesses as yellow-red triage, thus deserving clinical surveillance. This score has increased the rate of clinical complications which, according to the time survival curve could be detectable roughly 237.8 days before the event developed.

Hemostatic changes in patients undergoing hemodialysis: Differences between central venous catheters and arterio-venous fistulas.

Failure to mature the fistula in patients undergoing hemodialysis leads to prolonged use of the central venous catheter (CVC) and can compromise the patency of the catheter and the arteriovenous fistula (AVF) due to thrombus development. To evaluate hemostatic changes in patients undergoing hemodialysis with prolonged use of CVC or AVF. Cross-sectional study with a total of 200 adult participants who were divided into the following groups: I:control; II: patients who had 5-8 months of CVC insertion; III: patients who had 9-36 months of insertion; IV patients who had 5-8 months of AVF; and V: patients who had 9-36 months of AVF. Platelet activation was investigated by expressions of GPIIb/IIIa and p-selectin using flow cytometry. The Elisa-thrombomodulin (TM) test was used to compare groups III and V. The p-selectin percentage expression of group I was 15.30 (12.30-16.80), II 23.25 (20.75-30.55); and III 54.00 (44.75-59.29) were significant (p < 0.001). Groups I, IV, and V were also significant (p < 0.001). The median fluorescence for GPIIb/IIIa for groups I, II, and III were significant (p < 0.0001). As for the Elisa test, an increased absorbance of TM was verified in patients who used the CVC 4372 (3951-4733) compared with those patients who used the AVF 2162 (1932-2485) (p < 0.0001). It can be concluded that CVC patients had a larger platelet expression of GPIIb/IIIa and p-selectin than AVF patients. The high concentration of TM in CVC patients may suggest a greater stimulation of the intrinsic than extrinsic coagulation pathways.

Downregulation of the endothelial histone demethylase JMJD3 is associated with neointimal hyperplasia of arteriovenous fistulas in kidney failure

Jumonji domain–containing protein-3 (JMJD3), a histone H3 lysine 27 (H3K27) demethylase, promotes endothelial regeneration, but its function in neointimal hyperplasia (NIH) of arteriovenous fistulas (AVFs) has not been explored. In this study, we examined the contribution of endothelial JMJD3 to NIH of AVFs and the mechanisms underlying JMJD3 expression during kidney failure. We found that endothelial JMJD3 expression was negatively associated with NIH of AVFs in patients with kidney failure. JMJD3 expression in endothelial cells (ECs) was also downregulated in the vasculature of chronic kidney disease (CKD) mice. In addition, specific knockout of endothelial JMJD3 delayed EC regeneration, enhanced endothelial mesenchymal transition, impaired endothelial barrier function as determined by increased Evans blue staining and inflammatory cell infiltration, and accelerated neointima formation in AVFs created by venous end to arterial side anastomosis in CKD mice. Mechanistically, JMJD3 expression was downregulated via binding of transforming growth factor beta 1–mediated Hes family transcription factor Hes1 to its gene promoter. Knockdown of JMJD3 enhanced H3K27 methylation, thereby inhibiting transcriptional activity at promoters of EC markers and reducing migration and proliferation of ECs. Furthermore, knockdown of endothelial JMJD3 decreased endothelial nitric oxide synthase expression and nitric oxide production, leading to the proliferation of vascular smooth muscle cells. In conclusion, we demonstrate that decreased expression of endothelial JMJD3 impairs EC regeneration and function and accelerates neointima formation in AVFs. We propose increasing the expression of endothelial JMJD3 could represent a new strategy for preventing endothelial dysfunction, attenuating NIH, and improving AVF patency in patients with kidney disease.

Rules of 6 criteria predict dialysis fistula maturation but not all rules are equal

ObjectiveThe Rules of 6 (flow volume >600 mL/min, vein diameter >6 mm, vein depth <6 mm) are widely used to determine when an arteriovenous fistula (AVF) will support dialysis. Thus, we tested the utility of the Rules of 6 in clinical practice. MethodsWe retrospectively reviewed AVFs created at a single center from 2016 to 2019 for patients who had undergone dialysis within the same healthcare system. Clinical records and postoperative ultrasound studies were reviewed for the Rules of 6 criteria. Maturation was defined as use of the AVF with two needles for 75% of the dialysis sessions for a continuous 4-week period, with a mean flow of 300 mL/min or urea clearance (Kt/V) of 1.2. Predictors of maturation were assessed using logistic regression and receiver operating characteristic (ROC) curves. ResultsFive surgeons performed 202 AVFs of three types during 2016 to 2019 (radial-cephalic, n = 49; brachial-cephalic, n = 87; brachial-basilic, n = 66). Maturation occurred in 150 AVFs (74%; primary, n = 101 [50%]; assisted, n = 49 [24%]), while 52 (26%) failed to mature. Maturation did not vary by AVF type or patient sex or diabetes status. A higher body mass index was associated with failure to mature (P = .004). Only 16 mature AVFs (11%) met all three Rules of 6 using mean values for flow, diameter, and depth. However, 101 (67%) met all three Rules using the extreme, maximum or minimum, values. On multivariate analysis, each Rule of 6 was independently associated with maturation. If all three Rules were met, the AVF was nearly 10-fold more likely to have matured compared with an AVF satisfying no Rule. The body mass index correlated strongly with the vein depth (P < .001); however, both characteristics independently predicted maturation. The chance of maturation was highest if flow and depth Rules were met (positive predictive value [PPV], 93%); if all three rules were met, the PPV was 92%. The ROC area under curve (AUC) values for meeting flow volume and vein depth Rules together were higher than if all three Rules had been satisfied (0.784 vs 0.754). The PPV for diameter alone (78%) was the lowest of all PPVs for the three Rules and the ROC-AUC was only 0.588. If all three Rules together were not satisfied using extreme values, the negative predictive value was only 47%. ConclusionsThe Rules of 6 predict AVF maturation, especially when using extreme, maximum or minimum, values to satisfy each Rule. Flow volume and vein depth together predict maturation equally as well as meeting all three Rules. Vein diameter seems less important. The Rules of 6 might be too stringent if used exclusively to predict for functional AVF maturation.

Feasibility of Creation of an Endovascular Arteriovenous Fistula in Patients Undergoing Preoperative Vascular Mapping.

The first endovascular arteriovenous fistula (endoAVF) device (WavelinQ), a novel percutaneous technique of AVF creation, was approved by the Food and Drug Administration in 2018 and has been placed in a small number of United States patients on hemodialysis. It is unknown how often patients with advanced CKD have vascular anatomy suitable for WavelinQ creation. The goal of this study was to determine the proportion of patients with vascular anatomy suitable for WavelinQ creation and to assess patient characteristics associated with such suitability. All patients referred for vascular access placement at a large academic medical center underwent standardized preoperative sonographic vascular mapping to assess suitability for an AVF. During a 2-year period (March 2019 to March 2021), we assessed the suitability of the vessels for creation of WavelinQ. We then compared the demographic characteristics, comorbidities, and vascular mapping measurements between patients who were or were not suitable for WavelinQ. During the study period, 437 patients underwent vessel mapping. Of these, 51% of patients were eligible for a surgical AVF, and 32% were eligible for a WavelinQ AVF; 63% of those suitable for a surgical AVF were also suitable for a WavelinQ AVF. Patients with a vascular anatomy suitable for WavelinQ were younger (age 55±15 versus 60±14 years, P=0.01) but similar in sex, race, diabetes, hypertension, coronary artery disease, and peripheral artery disease. Among patients with CKD with vascular anatomy suitable for a surgical AVF, 63% are also suitable for a WavelinQ endoAVF. Older patients are less frequently suitable for WavelinQ.

Dual-phase contrast-enhanced CT evaluation of dural arteriovenous fistula in patients with pulsatile tinnitus as an initial symptom

PurposeIntracranial dural arteriovenous fistula (DAVF) can cause pulsatile tinnitus (PT). The purpose of this study was to investigate the diagnostic performance of dual-phase contrast-enhanced CT (DP-CECT) for DAVF in PT patients compared with digital subtraction angiography (DSA). MethodFrom February 2015 to April 2021, PT patients undergoing routine DSA examination were prospectively analyzed. Patients with and without DAVF diagnosed by DSA were included. In DP-CECT, the radiological signs related to DAVF were assessed as follows: asymmetric external carotid artery (ECA) branches, asymmetric enhancement of intracranial or extracranial veins, asymmetric venous collaterals in extracranial space, and shaggy tentorium or venous sinus on CTA; asymmetric enhancement of intracranial or extracranial veins on CTV; numerous transcalvarial channels and asymmetric size of foramen spinosum on high-resolution CT (HRCT). Results253 PT patients receiving DSA were enrolled, and these patients had previously been screened by DP-CECT. Forty-six patients were diagnosed as DAVF by DSA. Therefore, the prevalence of DAVF was 18% (46/253) in patients with PT as the initial symptom. The sensitivity and specificity of DP-CECT for diagnosis of DAVF were 96% and 100%. The sensitivity of individual CTA signs ranged from 65% to 93%, and specificities ranged from 83% to 100%. The sensitivity of CTV sign was 80%, and specificity was 100%. The sensitivity of individual HRCT signs ranged from 48 to 52% and specificities from 61 to 100%. ConclusionsDAVF is not rare in patients with PT as the initial symptom. DP-CECT can be used for screening DAVF in patients with PT.

Differences in Arteriovenous Fistula Maturation between Diabetes Mellitus and Non-Diabetes Mellitus in Chronic Renal Failure Patients in Padang

Background: Arteriovenous fistula (AVF) is the preferred vascular access for hemodialysis (HD). Several factors can affect AVF maturity, such as diabetes. This study aims to determine the differences in the maturation of arteriovenous fistulas between diabetes mellitus and non-diabetes mellitus in patients with chronic kidney failure in Padang.&#x0D; Methods: This was a comparative cross-sectional study of patients with chronic kidney failure who underwent arteriovenous fistula surgery in Padang. The sampling technique in this study was consecutive sampling. The analysis was carried out using statistical analysis according to the existing data scale and using SPSS software.&#x0D; Results: This study involved 46 patients with chronic kidney failure who underwent arteriovenous fistula surgery in Padang, of which 23 patients with diabetes mellitus and 23 patients with non-diabetes mellitus. The diameter of the arteriovenous fistula between diabetes mellitus and non-diabetes mellitus in patients with chronic renal failure had a significant difference (p&lt;0.05). There was no significant difference in flow, depth, and maturation of arteriovenous fistulas in patients with diabetes mellitus and non-diabetes mellitus with chronic renal failure.&#x0D; Conclusion: There is no difference in the maturation of arteriovenous fistula between patients with diabetes mellitus and non-diabetes mellitus