Ankle-brachial index associates with arteriovenous fistula stenosis.

BACKGROUND: Arteriovenous fistula (AVF) stenosis is associated with pre-existing arterial atherosclerosis of AVF and results in significant morbidity and hospitalization for hemodialysis patients. The ankle brachial index (ABI) is a noninvasive method of assessing atherosclerosis. This study was to examine whether ABI is a significant predictor for AVF stenosis. METHODS: This was a retrospective, longitudinal cohort study. Patients with hemodialysis between 1 January 2016 and 31 December 2022 were reviewed. ABI was assessed in January 2016. AVF stenosis was diagnosed by fistulography. RESULTS: A total of 82 patients were included. Forty-two patients experienced AVF stenosis. The univariate logistic regression analysis showed that AVF stenosis was associated with age (OR: 1.045, p = 0.033), DM status (OR: 5.529, p = 0.013), 7-year averaged cholesterol level (OR: 1.018, p = 0.034), 7-year averaged triglyceride level (OR: 1.007, p = 0.017), and ABI (OR: 0.011, p < 0.001). In multivariate logistic regression analysis, ABI was a strong predictor for AVF stenosis (OR: 0.036, p = 0.023). Then, a cut-off point of ABI with optimal sensitivity and specificity for AVF stenosis was 1.01. An analysis of time to events with adjustment for other variables showed that patients with ABI < 1.01 were significantly associated with AVF stenosis (HR: 3.859, p < 0.001). CONCLUSIONS: ABI below 1.01 was associated with AVF stenosis. This finding may be useful in tailoring surveillance programs for monitoring AVF function.

Study of Osteopontin as a Marker of Arteriovenous Shunt Stenosis in Hemodialysis Patients.

INTRODUCTION: Although arteriovenous fistula (AVF) is the recommended access for hemodialysis (HD), it carries a high risk for stenosis. Since osteopontin (OPN) is implicated in the process of vascular calcification in HD patients, OPN may be a marker for AVF stenosis. The present study evaluated OPN as a potential marker of AVF stenosis in HD patients. METHODS: Diagnosing a stenotic lesion was made by combining B mode with color and pulse wave Doppler imaging. Criteria for diagnosis of stenotic AVF included 50% reduction in diameter in B mode in combination with a 2-3-fold increase of peak systolic velocity compared with the unaffected segment. RESULTS: The present study included 60 HD patients with stenotic AVF and 60 patients with functional AVF. Comparison between the two groups revealed that patients in the former group had significantly higher serum OPN levels [median (IQR): 17.1 (12.1-30.4) vs 5.8 (5.0-10.0) ng/mL, p<0.001]. All patients were classified into those with low (< median) and with high (≥ median) OPN levels. Comparison between these groups revealed that the former group had a significantly lower frequency of stenotic AVF (31.7 vs 68.3%, p<0.001) and a longer time to AVF stenosis [mean (95% CI): 68.4 (54.7-82.1) vs 46.5 (39.6-53.4) months, p=0.001]. CONCLUSION: OPN levels in HD patients may be useful markers for predicting and detecting AVF stenosis.

Comparing non-invasive diagnostic methods for arteriovenous fistula stenosis: a prospective study.

PURPOSE: International guidelines recommend screening for arteriovenous fistula (AVF) stenosis using various non-invasive methods. We evaluate different non-invasive AVF flow measurements for detecting AVF stenosis. METHODS: Twenty-three haemodialysis patients with suspected AVF stenosis are enrolled based on abnormal physical signs or high venous pressure during dialysis. Ultrasound dilution, urea dilution, Doppler ultrasonography, and fistulography are performed on all patients. The accuracy of three non-invasive methods is compared. RESULTS: Fistulography reveals AVF stenosis in 18 patients, 12 of whom have severe stenosis (greater than 50% stenosis in diameter). Concerning the location of the stenosis lesions, eight are at the inflow site, six at the outflow site, and four on both sites. Receiver operating characteristic curve analysis shows that Doppler ultrasonography has a high discriminative ability and the averaged areas under the curves are 0.933 (95% confidence interval [CI]; 0.81 to 0.99) for stenosis and 0.929 (95% CI 0.82-0.99) for severe stenosis. The sensitivity of each method for the prediction of access stenosis using ultrasound dilution, urea dilution, and Doppler ultrasonography is 73%, 73%, and 80%, respectively. The respective specificity of each method is 40%, 80%, and 100%, respectively. Physical examination (PE) shows an 80% sensitivity and 80% specificity in the detection of AVF stenosis. The combination of Doppler ultrasound with PE produces the highest sensitivity (93%) for detecting AVF stenosis. CONCLUSIONS: Doppler ultrasound combined with physical examination is more accurate than other non-invasive methods for detecting AVF stenosis.

Analysis of Factors Influencing Restenosis after Percutaneous Transluminal Angioplasty.

INTRODUCTION: This study aimed to analyse the influencing factors of arteriovenous fistula (AVF) ultrasound-guided restenosis after percutaneous transluminal angioplasty (PTA). METHODS: This was a retrospective trial. The clinical data and ultrasound examination data of patients in maintenance haemodialysis who received ultrasound-guided PTA for AVF stenosis at our hospital from January 2018 to December 2020 were retrospectively analysed. The fistula patency and the relationship between age, dialysis age, fistula service age, combined hypertension, diabetes, hypoproteinaemia, stenosis type, fistula location, and patency rate after the operation were evaluated. RESULTS: A total of 128 participants were evaluated. The results showed that being over 65 years old, with complications from hypertension, diabetes, and hypoproteinaemia, are all risk factors affecting the patency of postoperative internal fistulas. Compared with lumen stenosis, the patency rate of hyperplastic endothelial stenosis (p = 0.014) and thrombotic stenosis (p = 0.017) was lower, and the difference was statistically significant. The patency rate of the mixed site (p = 0.010), the anastomotic site (p = 0.041), and the cephalic vein near the anastomotic site (p = 0.018) was lower than the forearm cephalic vein, and the difference was statistically significant. CONCLUSION: Age, hypertension complications, diabetes complications, hypoproteinaemia, and the type and location of the AVF stenosis were essential for vascular patency of internal fistulas after PTA. Other risk factors of restenosis after PTA still need further research.

Relationship between Monocytes and Stenosis-Related Autologous Arteriovenous Fistula Dysfunction.

BACKGROUND: Arteriovenous fistula (AVF) is considered to be the best choice of vascular access, but the maturation rate and patency rate of AVF are not satisfactory. Many studies have explored the influencing factors of AVF failure but do not involve the direct relationship between monocyte count and AVF failure. This study aims to explore the relationship between monocyte count and AVF dysfunction related to stenosis. METHODS: From September 2017 to September 2018, basic clinical data and laboratory parameters of patients were collected. All included patients were followed up to September 2019. The stenosis-related AVF failure events that occurred after the patient included in the study and the time of their occurrence were recorded. All patients were divided into 3 groups based on the tertile of monocyte count. Kaplan-Meier method was used to compare the patency rate of AVF in each group. The effects of variables on AVF failure were analyzed. A multivariate Cox regression model with p < 0.05 was included in the univariate Cox regression analysis. RESULTS: A total of 120 patients were included in this study. According to the recorded baseline monocyte count levels, they were divided into 3 groups according to their tertiles, 34 cases in the T1 group (T1 < 0.32 × 109/L), 44 cases in the T2 group (0.32 ≤ T2 < 0.51 × 109/L), and 42 cases in T3 group (T3 ≥0.51 × 109/L). After a median follow-up of 20 months, a total of 31 AVF failure events occurred. Kaplan-Meier survival curves showed that patients with a baseline monocyte count ≥0.51 × 109/L had the lowest patency rate of AVF (log-rank test χ2 = 7.525, p = 0.023). After adjusting to basic clinical data and biochemical indicators, there were statistically significant differences in patency rates of the 3 groups (hazard ratio = 2.774, 95% CI = 1.092-7.043). CONCLUSION: Monocyte count ≥0.51 × 109/L is an independent risk factor for AVF failure, and AVF failure caused by monocytes may be driven by inflammation.

NF-κB Decoy Oligodeoxynucleotide-Coated Balloon Catheter for Arteriovenous Fistula in Hemodialysis.

INTRODUCTION: New treatments to inhibit neointimal formation after percutaneous transluminal angioplasty (PTA) are needed for patients undergoing chronic hemodialysis (HD). We compared the efficacy and safety of AMG0102, a balloon catheter containing nuclear factor κB (NF-κB) decoy oligodeoxynucleotide (ODN) with the PTA balloon catheter (control group) for arteriovenous fistula (AVF) stenosis. METHODS: In total, 175 patients (age ≥20 years, undergoing HD, with venous stenosis at the anastomotic region) were registered in this prospective open-label, randomized study. Patients were followed postoperatively for 36 weeks. The duration of primary patency on the targeted venous stenosis site (primary endpoint) was estimated by the Kaplan-Meier method. RESULTS: A lower restenosis risk was observed for the AMG0102 group, but it was not statistically significant (stratified log-rank test P = 0.250, hazard ratio [HR] 0.774; 95% confidence interval [CI]: 0.500-1.198). The median duration of primary patency was 245 days and 172 days in the AMG0102 and control groups, respectively. After stratification based on the status of diabetes complications, the HR was 0.666 (95% CI: 0.366-1.212; P = 0.183) and the median duration of primary patency was prolonged by 108 days in the AMG0102 group with diabetes complications (245 days) compared with the control group (137 days). Adverse event (AE) incidence up to 36 postoperative weeks did not differ between groups. Four device failures occurred in 3 patients (AMG0102 group), but none resulted in AEs. CONCLUSION: Further modifications to enhance NF-κB decoy ODN uptake and efficacy are necessary to show its clinical utility for AVF stenosis in chronic HD.

Ultrasound evaluation and interventional therapy for peripheral vascular access stenosis in dialysis patients / 中华肾脏病杂志

Objective To investigate the patency rate and restenosis after percutaneous transluminal angioplasty (PTA) for the treatment of arteriovenous fistula (AVF) and arteriovenous graft (AVG) stenosis in dialysis patients. Methods The patients who were successfully treated by PTA for the first time in the blood purification center of the 2nd Affiliated Hospital of Nanjing Medical University from January 2016 to June 2017, including 71 cases of AVF in the forearm, 52 cases of AVF in the upper arm and 59 cases of AVG were recorded. The data of different stenosis parts were analyzed before and after treatment and followed up for 12 months. The initial patency rate and assisted-PTA patency rate were observed at 3 months, 6 months, 9 months, and 12 months after ultrasound interventional therapy, and the initial patency time for patients who needed to reintervention among all types of pathways were recorded. Results The initial patency rates at 3 months, 6 months, 9 months and 12 months after ultrasound interventional therapy were 98.59％, 90.14％, 71.93％, 54.93％ respectively in forearm AVF, 90.38％, 65.38％, 42.31％, 32.69％ respectively in upper arm AVF, 91.53％, 32.20％, 6.78％, 1.69％ respectively in AVG, and the PTA-assisted patency rates were 98.59％, 97.18％, 95.77％, 94.37％ respectively in forearm AVF, 92.31％, 86.54％, 84.62％, 80.77％respectively in upper arm AVF, 100.00％, 98.31％, 96.61％, 93.22％ respectively in AVG, while the initial patency time was (8.99 ± 3.54) months in forearm AVF, (6.33 ± 3.01) months in upper arm AVF, (4.80 ± 1.40) months in AVG respectively. Conclusions Ultrasound can comprehensively evaluate the function of peripheral vascular access, guide PTA treatment, and evaluate treatment outcomes. Ultrasound intervention therapy has best initial patency rate for forearm AVF stenosis. The prognosis of upper arm AVF stenosis PTA is relatively poor due to the easy cephalic stenosis. Although AVG has a short interval of restenosis, it can achieve a better long-term patency rate through regular intervention with ultrasound intervention.

Value of doppler ultrasonography in the study of hemodialysis peripheral vascular access dysfunction.

OBJECTIVE: The main objectives of this study were to evaluate the sensitivity and specificity of duplex Doppler ultrasonography in the study of hemodialysis peripheral vascular access dysfunction and to analyze the resistance index and flow in the afferent artery. MATERIAL AND METHODS: We prospectively studied 178 patients with 178 peripheral vascular accesses that were dysfunctional in at least three consecutive hemodialysis sessions. Patients underwent duplex Doppler ultrasonography and clinical and laboratory follow-up for three months (provided angiography findings were negative). We calculated the sensitivity, specificity, predictive values, and coefficients of probability. We studied the morphology of the afferent artery, the arteriovenous anastomosis, and the efferent vein, and we measured the resistance index and the flow of the afferent artery, the diameter of the anastomosis, and the flow and peak systolic velocity in the efferent vein. RESULTS: The final sample consisted of 159 patients. The sensitivity, specificity, positive and negative predictive values, and positive and negative coefficients of probability were 0,98 (95% CI: 0,88-1.00), 0,74 (95% CI: 0,66-0,81), 0,96, 0,82, 3.7, and 0,03, respectively. The resistance index was less than 0,5 in 78.5% of the peripheral vascular accesses with normal function and greater than 0,5 in 86.1% of the dysfunctional peripheral vascular accesses. We found aneurysms in 19 of the native peripheral vascular accesses and pseudoaneurysms in 7 of the prosthetic grafts. Inverted flow was seen in 57 peripheral vascular accesses. CONCLUSION: Duplex Doppler ultrasonography is an efficacious method for detecting and characterizing stenosis and thrombosis in peripheral vascular accesses, and it provides information about the morphology and hemodynamics.