A Systematic Review and Meta-Analysis of Circulating Biomarkers Associated with Failure of Arteriovenous Fistulae for Haemodialysis

The influence of near-infrared therapy on arteriovenous fistula patency in haemodialysis patients: A multicentre, randomised, controlled clinical trial

BACKGROUND

Arteriovenous fistula (AVF) is the preferred vascular access for patients undergoing haemodialysis (HD). AVF malfunction remains a major clinical problem and is a significant independent risk factor for death. Although far-infrared (FIR) therapy has been shown to reduce complications and improve the patency rate of AVFs in various studies, it has been cautiously recommended by the Kidney Disease Outcome Quality Initiative (KDOQI) guidelines for AVF care due to insufficient evidence. Therefore, it is necessary to identify more effective methods for preventing AVF dysfunction. Many in vitro studies and few clinical studies have examined the effects of near-infrared (NIR) therapy on the vasculature. This study will examine the effects of NIR therapy on AVF.

METHODS

A randomised, controlled, open-label, multicentre trial will compare the effect of NIR on AVF patency after 1 year of therapy with that of a control group of patients with existing AVF. One group of patients received NIR treatment above their AVFs, whereas the control group received regular care. The primary outcome is the primary fistula patency rate within 12 months. In addition, acute changes in inflammatory, vasodilatory and haemodynamic parameters after a single treatment in the first 40 participants will be examined. This study was registered in the Clinical Trials Registry (ChiCTR2300071305) at https://register.clinicaltrials.gov/.

DISCUSSIONS

This study will explore the long-term and acute effects of NIR on AVFs. The study findings will provide information that can be used to develop new technical support for the prevention of AVF dysfunction in patients undergoing haemodialysis.

Association between preoperative C-reactive protein to albumin ratio and late arteriovenous fistula dysfunction in hemodialysis patients: a cohort study

Arteriovenous fistula (AVF) dysfunction is a critical complication in hemodialysis (HD) patients, with inflammation potentially contributing to its development. This retrospective cohort study aimed to investigate the association between preoperative C-reactive protein to albumin ratio (CAR) and AVF dysfunction in Chinese HD patients. A total of 726 adults with end-stage renal disease who underwent new AVF placement between 2011 and 2019 were included. Multivariable Cox regression and Fine and Gray competing risk models were employed to assess the relationship between CAR and AVF dysfunction, considering death and renal transplantation as competing risks. Among 726 HD patients, 29.2% experienced AVF dysfunction during a median follow-up of 36 months. Adjusted analyses revealed that higher CAR levels were associated with an increased risk of AVF dysfunction, with a 27% higher risk per one-unit increase in CAR. Furthermore, patients with CAR values ≥ 0.153 exhibited a 75% elevated risk compared to those with CAR values < 0.035 (P = 0.004). The relationship between CAR and AVF dysfunction varied by the site of internal jugular vein catheter placement (P for trend = 0.011). Notably, the Fine and Gray analysis confirmed the association between CAR and AVF dysfunction, with a 31% increased risk per one-unit increase in CAR. The highest CAR tertile remained an independent predictor of AVF dysfunction (HR = 1.77, 95% CI 1.21-2.58, P = 0.003). These findings highlight the potential of CAR as a prognostic marker for AVF dysfunction in Chinese HD patients. Clinicians should consider CAR levels and catheter placement site when assessing the risk of AVF dysfunction in this population.

The Potential Roles of CHI3L1 in Failed Autologous Arteriovenous Fistula in End-Stage Renal Disease

Autologous arteriovenous fistula (AVF) is commonly placed for hemodialysis treatment. Recent studies show that increased baseline serum level of Chitinase-3-like protein 1 (CHI3L1) is independently associated with a higher risk of the early failure of forearm AVFs. However, the changes and mechanisms of CHI3LI in local vascular tissues of failed AVF have not be revealed. This study aims to conduct the expression and mechanism of CHI3L1 in vascular tissues from patients. Immunoreactivity of CHI3L1, matrix metalloproteinase 2 (MMP-2) and vascular endothelial growth factor-A (VEGF-A) were detected in vascular tissues collected from nine patients with AVF surgery. Due to the significant stenosis clinically, six of the nine patients received arteriovenous fistula reconstruction. The expression differences of CHI3L1 between the initial vascular tissues and failed AVF are significant (P < 0.05). Failed AVF due to stenosis shows intraluminal thrombus, collagen fiber rupture, fibrous connective tissue hyperplasia, tube wall thickening, neovascularization, scattered inflammatory cell infiltration in the tunica media as well as high CHI3L1 expression level, and the expression of MMP-2 (r = 0.9022, P = 0.0139) and VEGF-A (r = 0.8355, P = 0.0393) was positively correlated with CHI3L1. CHI3L1 expression in vascular tissues possibly plays an important role in AVF failure. MMP-2 and VEGF-A may participate in venous stenosis with CHI3L1.

Plasma Interleukin-6 Level Predicts the Risk of Arteriovenous Fistula Dysfunction in Patients Undergoing Maintenance Hemodialysis

Systemic inflammation has been proposed as a relevant factor of vascular remodeling and dysfunction. We aimed to identify circulating inflammatory biomarkers that could predict future arteriovenous fistula (AVF) dysfunction in patients undergoing hemodialysis. A total of 282 hemodialysis patients were enrolled in this prospective multicenter cohort study. Plasma cytokine levels were measured at the time of data collection. The primary outcome was the occurrence of AVF stenosis and/or thrombosis requiring percutaneous transluminal angioplasty or surgery within the first year of enrollment. AVF dysfunction occurred in 38 (13.5%) patients during the study period. Plasma interleukin-6 (IL-6) levels were significantly higher in patients with AVF dysfunction than those without. Diabetes mellitus, low systolic blood pressure, and statin use were also associated with AVF dysfunction. The cumulative event rate of AVF dysfunction was the highest in IL-6 tertile 3 (p = 0.05), and patients in tertile 3 were independently associated with an increased risk of AVF dysfunction after multivariable adjustments (adjusted hazard ratio = 3.06, p = 0.015). In conclusion, circulating IL-6 levels are positively associated with the occurrence of incident AVF dysfunction in hemodialysis patients. Our data suggest that IL-6 may help clinicians identify those at high risk of impending AVF failure.

Systemic Profile of Cytokines in Arteriovenous Fistula Patients and Their Associations with Maturation Failure

Background

Systemic cytokines are elevated in patients with chronic kidney disease (CKD) and on hemodialysis compared with the general population. However, whether cytokine levels interfere with vascular remodeling, increasing the risk of arteriovenous fistula (AVF) failure, remains unknown.

Methods

This is a case-control study of 64 patients who underwent surgery for AVF creation (32 with AVF maturation failure and 32 matching controls with successful maturation). A total of 74 cytokines, including chemokines, interferons, interleukins, and growth factors, were measured in preoperative plasma samples using multiplex assays. Sixty-two patients were included in the statistical analyses. Associations with AVF failure were assessed using paired comparisons and conditional logistic regressions accounting for paired strata.

Results

Seven cytokines were significantly higher in patients with AVF maturation failure than in matching controls (G-CSF, IL-6, MDC, RANTES, SDF-1α/β, TGFα, and TPO). Of these, G-CSF (odds ratio [OR]=1.71; 95% confidence interval [95% CI], 1.05 to 2.79 per 10 pg/ml), MDC (OR=1.60, 95% CI, 1.08 to 2.38 per 100 pg/ml), RANTES (OR=1.55, 95% CI, 1.10 to 2.17 per 100 pg/ml), SDF-1α/β (OR=1.18, 95% CI, 1.04 to 1.33 per 1000 pg/ml), and TGFα (OR=1.39, 95% CI 1.003, 1.92 per 1 pg/ml) showed an incremental association by logistic regression.

Conclusions

This study identified a profile of plasma cytokines associated with adverse maturation outcomes in AVFs. These findings may open the doors for future therapeutics and markers for risk stratification.

Association between Preoperative Monocyte-to-Lymphocyte Ratio and Late Arteriovenous Fistula Dysfunction in Hemodialysis Patients: A Cohort Study

BACKGROUND

Inflammation appears to be at the biological core of arteriovenous fistula (AVF) dysfunction, and the occurrence of AVF dysfunction is related to high death and disability in hemodialysis (HD) patients. Despite several studies on the correlations between AVF dysfunction and inflammatory indicators, how AVF dysfunction is related to the monocyte-to-lymphocyte ratio (MLR) is much unclear. We hypothesize that preoperative MLR is associated with AVF dysfunction in Chinese HD patients.

METHODS

In this single-center retrospective cohort study, totally 769 adult HD patients with a new AVF created between 2011 and 2019 were included. Association of preoperative MLR with AVF dysfunction (thrombosis or decrease of normal vessel diameter by >50%, requiring either surgical revision or percutaneous transluminal angioplasty) was assessed by multivariable Cox proportional hazard regression.

RESULTS

The patients were aged 55.8 ± 12.2 years and were mostly males (55%). During the average 32-month follow-up (maximum 119 months), 223 (29.0%) patients had permanent vascular access dysfunction. In adjusted multivariable Cox proportional hazard regression analyses, the risk of AVF dysfunction was 4.32 times higher with 1 unit increase in MLR (hazard ratio [HR]: 5.32; 95% confidence interval [CI]: 3.1-9.11). Compared with patients with MLR <0.28, HRs associated with an MLR of 0.28-0.41 and ≥0.41 are 1.54 (95% CI: 1.02-2.32) and 3.17 (2.18-4.62), respectively.

CONCLUSIONS

A higher preoperative MLR is independently connected with a severer risk of AVF dysfunction in HD patients. Its clinical value should be determined in the future.

Relationship Between Arteriovenous Fistula Stenosis and Circulating Levels of Neutrophil Granule Proteins in Chronic Hemodialysis Patients

BACKGROUND

Arteriovenous fistula (AVF) stenosis leading to its failure is a major cause of morbidity in hemodialysis patients; however, detailed pathogenesis of AVF stenosis is still under investigation. To date, monocytes/macrophages have been considered pivotal players in chronic inflammation of vascular disease including atherosclerosis and AVF stenosis. However, recent evidence strongly suggests that neutrophils and neutrophil granule proteins are important contributors to vascular disease. The aim of the present study was to evaluate the relationship between AVF stenosis and neutrophil activation by measuring circulating levels of neutrophil elastase (NE) and lactoferrin, enzymes released on neutrophil activation, as well as other inflammation markers including neutrophil counts.

METHODS

This was a single-center, prospective observational study conducted on 83 prevalent hemodialysis patients with AVF. Blood levels of biomarkers and sonography (US) measurement were assessed at baseline and 1 year after enrollment. Clinical follow-up continued for one more year (a total of 2 years for each patient) to observe any AVF events.

RESULTS

Circulating levels of both NE and lactoferrin positively correlated with the degree of AVF stenosis. Patients with significant AVF stenosis had older AVFs, higher neutrophil-to-lymphocyte ratio (NLR), and higher circulating levels of NE and lactoferrin. On multivariate logistic regression analysis, both circulating levels of NE and NLR remained independent predictors of significant AVF stenosis.

CONCLUSIONS

Circulating levels of NE and the NLR were identified as independent predictors of at-risk AVF with significant stenosis. Our data suggest the potential role of neutrophil and innate immunity activation on the development of AVF stenosis.

Effect of preoperative exercise on vascular caliber and maturation of arteriovenous fistula: the physicalfav trial, a randomized controlled study

BACKGROUND AND OBJECTIVES

Autologous arteriovenous fistula (AVF) is the best vascular access for hemodialysis. Distal forearm radiocephalic fistula is the best option, although the primary failure rate ranges from 20% to 50%. The main objective of the PHYSICALFAV trial was to evaluate the effect of preoperative isometric exercise on vascular caliber, percentage of distal arteriovenous fistula, and primary failure rate.

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

The PHYSICALFAV trial (NCT03213756) is an open-label, multicenter, prospective, randomized, controlled trial (RCT). A total of 138 patients were randomized 1:1 to the exercise group (exercises combining a handgrip device and an elastic band for 8 weeks) or the control group (no exercise) and followed up with periodic Doppler ultrasound (DU) examinations.

RESULTS

After 8 weeks of preoperative isometric exercise, in the exercise group, significant increases were detected in venous caliber (2.80 ± 0.95 mm vs 3.52 ± 0.93 mm [p < 0.001]), arterial caliber (2.61 ± 0.82 mm vs 2.74 ± 0.80 mm [p = 0.008]), arterial peak systolic velocity (66.34 ± 19.2 cm/s vs 71.03 ± 21.5 cm/s [p 0.043]), and maximum strength (28.35 ± 9.16 kg vs 32.68 ± 10.8 kg [p < 0.001]). Distal radiocephalic fistulas were performed in 75% of the exercise group patients compared with 50.8% in the control group (p = 0.030). The global primary failure rate was very low in both groups (7% exercise group vs 14% control group [p = 0.373]).

CONCLUSION

Isometric preoperative exercise can improve vascular caliber and increase the possibility of performing distal arteriovenous fistula, with no significant differences in primary failure rate.

Relationship between vascular cell adhesion molecule-1 (VCAM-1), soluble receptor for advanced glycation end products (sRAGE) and functional hemodynamic parameters of arteriovenous fistula

BACKGROUND

The preferred vascular access for hemodialysis is represented by arteriovenous fistula (AVF) due to fewer complications and more prolonged survival. Considerable efforts have been made to identify biomarkers associated with AVF dysfunction, but results are conflicting. Vascular cell adhesion molecule (VCAM-1) and advanced glycation end products are involved in atherogenesis, vascular calcification, peripheral artery disease, and neointimal hyperplasia in renal and non-renal patients. The objective of this study was to evaluate whether there is an association between VCAM-1, soluble receptor for advanced glycation end products (sRAGE), NcarboxymethylLysine (CML), and arteriovenous fistula dysfunction (AVF).

METHODS

VCAM-1, sRAGE, and CML were performed using the ELISA technique in 88 HD patients. Ultrasound assessment of AVF reports brachial artery blood flow (Qa), brachial resistivity index (RI), presence of calcification, and the diameter. AVF dysfunction was defined as a brachial artery Qa ⩽ 500 ml/min or RI ⩾ 0.5.

RESULTS

The median level of VCAM-1 [2676.5(2206.8-4203.9) versus 2613.2(1885.7-3161.8), p 0.026] was significantly higher in patients with AVF dysfunction compared to the rest of the patients. sRAGE and CML were higher in this group but without statistical significance. In patients with AVF dysfunction, significant positive correlations were found between VCAM-1and sRAGE (r = 0.417, p = 0.001), RI (r = 0.313, p = 0.046), dialysis vintage (r = 0.540, p < 0.001), AVF vintage (r = 0.336, p = 0.032), intima-media thickness (r = 0.423, p = 0.006) and C-reactive protein (r = 0.315, p = 0.045). VCAM-1 correlated inversely with cholesterol (r = -0.312, p = 0.047), triglycerides (r = -0.358, p = 0.021), body mass index (r = -0.388, p = 0.012). In multivariate regression analysis, VCAM-1 (p = 0.013) and sRAGE (p = 0.01) remained significant predictors of RI and Qa. Logistic regression disclosed calcification, VCAM-1, as risks factors for AVF dysfunction.

CONCLUSION

The results we obtained showed that patients with AVF dysfunction had a significantly higher level of VCAM-l. A positive correlation between VCAM-1 and sRAGE was identified in this group.

Relationship of arteriovenous fistula stenosis and thrombosis with the platelet-lymphocyte ratio in hemodialysis patients

BACKGROUND

The platelet-lymphocyte ratio, which was reported to have a strong relationship with chronic inflammation and thrombosis, is a useful biomarker. The purpose of this study was to evaluate the relationship between the platelet-lymphocyte ratio, arteriovenous stenosis, and thrombosis in patients with chronic renal failure.

METHODS

Patients who were referred to our interventional radiology department due to arteriovenous fistula dysfunction from dialysis units between August 2015 and December 2018 were retrospectively reviewed. In the study, 95 patients with arteriovenous fistula access problems were included. Patients were divided into two groups: stenosis (n = 52) and thrombosis (n = 43). Thirty-six subjects with a patent left radiocephalic arteriovenous fistula proven by both color Doppler ultrasonography and clinically were added to the control group. Blood samples were obtained on the same day before the fistulography.

RESULTS

Platelet counts, lymphocyte counts, and platelet-lymphocyte ratio were found to be significantly different between the three groups. After the Bonferroni post hoc analysis, there was a significant difference between the stenosis and control group (p = 0.017), and the thrombosis and control group (p < 0.001) in terms of the platelet-lymphocyte ratio. No significant difference for any parameter was found between stenosis and thrombosis group.

CONCLUSION

High levels of the platelet-lymphocyte ratio may be a supportive finding of arteriovenous fistula stenosis and thrombosis and can be taken into consideration during hemodialysis-dependent patients' follow-up.

The Presence of a High Peak Feature Within Low-Average Shear Stimuli Induces Quiescence in Venous Endothelial Cells

Wall shear stress (WSS) is an important stimulus in vascular remodelling and vascular lesion development. The current methods to assess and predict the risk associated with specific unsteady WSS consider the WSS mean values or the presence of reverse phases described by the oscillatory shear index. Recent evidence has shown that the accuracy of these methods is limited, especially with respect to the venous environment. Unsteady WSS are characterised by several features that may individually affect endothelial cells. Consequently, we assessed the effects of averaged WSS (TAWSS), temporal WSS gradient (TWSSG), maximum WSS (WSS peak) and reverse phase (OSI) by applying different WSS profiles to venous EC in-vitro, using a real-time controlled cone-and-plate cell-shearing device for 24 h. We found that TWSSG and WSS peak affect cell elongation and alignment respectively. We also found that the WSS waveforms with a peak of 1.5 Pa or higher significantly correlate with the induction of a protective phenotype. Cell phenotype induced by these high peak waveforms does not correlate to what is predicted by the hemodynamic indices currently used. The definition of reliable hemodynamic indices can be used to inform the computational models aimed at estimating the hemodynamic effects on vascular remodelling.

Angiography and phlebography in a hemodialysis population: A retrospective analysis of interventional results

OBJECTIVE

To clarify the reasons and beneficial effects and duration of arteriovenous fistula patency after radiological interventions in arteriovenous fistula. The patients investigated were referred due to arteriovenous fistula access flow problems.

MATERIAL AND METHODS

In 174 patients, 522 radiological investigations and endovascular treatments such as percutaneous transluminal angioplasty were analyzed, retrospectively. All investigations were performed due to clinical suspicion of impaired arteriovenous fistula function.

RESULTS

Arterial stenosis was significantly more frequent among patients with diabetic nephropathy (p < 0.001) and interstitial nephritis (p < 0.001). According to the venous stenosis, the diagnosis did not affect the frequency (p = 0.22) or the degree (p = 0.39) of stenosis. The degree of stenosis prior to percutaneous transluminal angioplasty correlated significantly with the degree of remaining stenosis after intervention (p < 0.001). Of the 174 patients, 123 (71%) performed a total of 318 investigations including percutaneous transluminal angioplasty. Repeated percutaneous transluminal angioplasty was performed significantly more often in patients with diabetic nephropathy. The median times to the first percutaneous transluminal angioplasty and to the subsequent percutaneous transluminal angioplasties were 9.5 and 5 months, respectively. Arteriovenous fistula in patients with diabetic nephropathy performed similar to most other diagnoses, although performing more percutaneous transluminal angioplasty/patient than most other diagnoses.

CONCLUSION

Many patients could maintain long-term patency of arteriovenous fistula, including those with diabetic nephropathy, with repeated interventions; this motivates a closer follow-up for these patients. Clinically significant stenosis should be dilated as meticulously and as soon as possible. Occlusions of the arteriovenous fistula in most instances can be successfully thrombolyzed or dilated upon early diagnosis.

Significant association of anti-platelet factor 4/heparin antibody with cardiovascular disease in hemodialysis patients: a longitudinal 7-year study

BACKGROUND

Hemodialysis patients have a high incidence of anti-platelet factor 4/heparin antibody (PF4-H Ab) and are at a high risk of cardiovascular disease. This study determines the association between PF4-H Ab and cardiovascular events including coronary artery disease (CAD), ischemic stroke (IS), and native arteriovenous fistula thrombosis (AVFT), in a longitudinal 7-year follow-up.

PATIENTS AND METHODS

84 hemodialysis patients were enrolled. Data collection included chart reviews and assessments of laboratory records. PF4-H Ab was evaluated by ELISA and a titer ≥ 0.4 was defined to have PF4-H Ab.

RESULTS

30 patients were PF4-H Ab positive, 30 patients had CAD, 29 patients had IS, and 43 patients had AVFT. In Cox proportional hazard regression analysis, PF4-H Ab (HR 2.72, p = 0.01) was a significant risk factor for CAD. Age (HR 1.06, p = 0.003), PF4-H Ab (HR 4.53, p < 0.001), 7-year averaged serum phosphate levels (HR 0.53, p = 0.012), and 7-year averaged blood platelet count (HR 1.01, p = 0.029) were risk factors for IS. Age (HR 1.03, p = 0.047), PF4-H Ab (HR 3.57, p < 0.001), and 7-year averaged serum triglyceride levels (HR 1.01, p = 0.005) were risk factors for AVFT. In PF4-H Ab-positive groups, thrombocytopenia was not associated with CAD, IS, and AVFT by Fisher's test analysis.

CONCLUSION

This study reveals that PF4-H Ab is a risk factor for developing CAD, IS, and AVFT among hemodialysis patients.

Toward longitudinal studies of hemodynamically induced vessel wall remodeling

INTRODUCTION:

Autogenous arteriovenous fistula is the preferred vascular access for hemodialysis, but it has high rates of non-maturation and early failure due to vascular stenosis. Convincing evidence supports a key role of local hemodynamics in vascular remodeling, suggesting that unsteady and disturbed flow conditions may be related to stenosis formation in arteriovenous fistula. The purpose of our study was to explore the feasibility of coupling contrast-free magnetic resonance imaging and computational fluid dynamics in longitudinal studies to identify the role of local hemodynamic changes over time in inducing vessel wall remodeling in arteriovenous fistula.

METHODS:

We acquired contrast-free magnetic resonance imaging of arm vasculature at 1 week and 6 weeks after arteriovenous fistula creation in a 72-year-old patient. We then generated three-dimensional models and evaluated lumen cross-sectional area of arteriovenous fistula limbs. We performed high-resolution computational fluid dynamics to evaluate changes in local hemodynamics over time.

RESULTS:

Our contrast-free magnetic resonance imaging protocol provided good quality images in a short scan duration. We observed a homogeneous dilatation in the proximal artery, while there was a more pronounced lumen dilatation in the venous outflow as compared to a limited dilatation in the juxta-anastomotic vein. Furthermore, we observed a slight stabilization of the flow pattern over time, suggesting that vascular outward remodeling accommodates the flow to a more helicoidally phenotype.

CONCLUSION:

Coupling contrast-free magnetic resonance imaging and high-resolution computational fluid dynamics represents a promising approach to shed more light in the mechanisms of vascular remodeling and can be used for prospective clinical investigations aimed at identifying critical hemodynamic factors contributing to arteriovenous fistula failure.

Independent association of arteriovenous ratio index on the primary functional maturation of autologous radiocephalic arteriovenous fistula

OBJECTIVE

It has been hypothesized that a novel measurement technique of arteriovenous ratio (AVR) index obtained from inflow (radial artery diameter) to that of outflow (cephalic vein diameter) and its application through the Bernoulli effect has no impact on the primary functional maturation (FM) of autogenous radiocephalic arteriovenous fistula (RCAVF).

METHODS

A prospective consecutive single-center cohort study with intention to treat of 324 patients undergoing RCAVF during a period of 4 years was conducted. Variables of demographics, anatomic factors, laterality, comorbidities, anesthesia type, presence of intraoperative thrill, angle of anastomosis, and AVR index were assessed through univariate and multivariate logistic regression analysis on the end point of FM. The AVR was subjected to three decimal points to ensure maximal accuracy for best sensitivity and 1 - specificity by receiver operating characteristic curve. The χ² (subgroup) analyses were undertaken to investigate the differences in FM incidence within different ranges of AVR. Test of probability (P value) was considered to be significant with P < .05. Effect sizes were reported as odds ratio with their measure of uncertainty at 95% confidence intervals.

RESULTS

Among all variables, the AVR index remained the only independent factor associated with FM (66%; n = 214/324) of RCAVFs (P = .001; 95% confidence interval, 0.08-0.26). AVR of 1 to 1.06 was associated with 100% FM in RCAVFs. Decrease or increase of this index was associated with stepwise reduction in FM of RCAVFs (P < .05).

CONCLUSIONS

The suggested novel measurement technique (AVR index) is an independent predictor of FM in RCAVFs. This study implies that minimal diameter (ie, inflow artery dimeter to outflow cephalic vein diameter) mismatch (AVR, 1-1.06) irrespective of other variables remains crucial for optimal hemodynamics (pressure and velocity) of RACVFs and their primary FM.

Algorithmic salvage techniques in non-maturing radiocephalic arteriovenous fistulae with their long-term patency

INTRODUCTION

The aim of this study is to examine the role of five different operative salvage techniques with their long-term primary patency (PP) in an algorithmic manner in gaining primary functional maturation (FM) in radio cephalic arteriovenous fistulae (RCAVF) formation following their impairment.

METHODS

A prospective consecutive data collection on 195 patients undergoing only autogenous RCAVF formation from July 2013 to December 2015 was conducted. Each non-maturing fistula was then exposed to a salvage technique by an algorithmic methodology and their FM and PP was prospectively recorded.

RESULTS

Forty-two patients were exposed to five different salvages techniques, with a median age of 67 years (IQR, 27-90), cephalic vein diameter of 2 mm (IQR, 1.5-4 mm) and radial artery diameter of 1.8 mm (IQR,1.2-2.1 mm), demonstrated 63.1% FM and cumulative primary patency of 15.2 months (95% CI, 12.5-17.9) over a 21-month follow-up period.

CONCLUSIONS

Operative salvage techniques play an important role in achieving assisted functional maturation and long-term patency in RCAVF as an alternative and/or in conjunction with other minimally invasive procedures. These procedures can maximize access outcome, minimize bridging procedures, decrease complications and optimize patient anatomical resources for longer access provisions in an era of aging population.

High Preoperative Neutrophil-Lymphocyte Ratio (NLR) and Red Blood Cell Distribution Width (RDW) as Independent Predictors of Native Arteriovenous Fistula Failure

Objective: To study the association between a high preoperative neutrophil lymphocyte ratio (NLR) and red cell distribution width (RDW) with arteriovenous fistula (AVF) failure, as well as to determine the cut-off values in a South Asian population.

Materials and Methods: A total of 150 consecutive patients with a failed fistula who presented in the Department of Vascular Surgery between January 2014 and January 2016. Patients fulfilling the inclusion criteria were selected as defined as Case. They were compared with 150 patients who had matured fistulae (Control).

Results: A significant difference was found between the Case and Control groups in mean preoperative NLR (3.3±0.5 versus 2.2±0.9, P value=0.011) and RDW (15.9±2.9 versus 13.6±1.1%, P value of 0.02), respectively. Multivariate analysis revealed that NLR (Odds Ratios (OR) 1.39; 95% Confidence Intervals (CI) 1.02 to 2.08; P<0.001) and RDW (OR 1.39; 95%CI 1.11 to 1.69; P<0.001) were strong independent predictors of AVF failure. A receiver operating characteristic curve analysis showed a cut-off value of 2.65 (specificity 80%, sensitivity 98%) and 15.1 (specificity 79%, sensitivity 98%) for NLR and RDW, respectively.

Conclusion: Increased preoperative NLR and RDW were associated with a high rate of AVF failure in a South Asian population.