Factors affecting the patency of arteriovenous fistulas for dialysis access

Anchor versus parachute suturing technique in arteriovenous fistula creation for hemodialysis

INTRODUCTION

Chronic kidney disease (CKD) affects 13% of the global population and requires renal replacement therapy due to ESRD. Hemodialysis (HD) is the most common dialysis modality for ESRD patients, but establishing vascular access is challenging due to high morbidity and mortality rates. Arteriovenous fistulas (AVFs) are the gold standard for vascular access, but many fail due to anastomotic hemodynamics, vein diameter, and anastomatic suture technique. A prospective study was conducted to evaluate the impact of two continuous suturing techniques, the anchor technique and the parachute technique, on AVFs' initial outcomes.

METHODS

This randomized, controlled study involved adult patients who presented for AVF creation at our center. We divided the patients into two groups: anchors and parachutes. Four skilled vascular access surgeons performed the procedures. The primary goal was functional maturation of the AVF, defined as an AVF fistula ready to be cannulated with a cannulating vein length of at least 10 cm, a diameter of more than 6 mm, a depth of less than 6 mm, and a flow rate of 600 mL/min. Secondary goals included patency and complications such as bleeding, infection, steal syndrome, and aneurysmal dilatation at the anastomosis site. AVFs were evaluated immediately after surgery and during follow-up visits at the outpatient clinic. A duplex scan was performed to measure flow at various intervals. All patients provided appropriate written consent.

RESULT

The study involved 186 patients, with 86 excluded. 100 were randomized, with 5 cases losing follow-up and 3 deaths within 12 months. The follow-up continued until January 2024, with a mean of 8.6 months. The Parachute technique shows higher technical success (p value = 0.046) and primary patency at 30 days (p value = 0.014) compared to Anchor, but there is no statistical significance between both groups regarding functional maturation at 6 weeks (p value = 0.352). The parachute technique has a higher hematoma rate than the anchor technique (p value = 0.025), while other complications like intra-operative bleeding, postoperative bleeding, pseudoaneurysm formation, thrombosis, steal syndrome, and seroma formation show no significant differences. Nine patients, five of whom were diabetic and underwent conservative management, exhibited mild to moderate steal syndrome. This suggests an increased risk of steal syndrome among diabetic patients.

CONCLUSION

The parachute technique for AVF creation offers better technical success and short-term primary patency outcomes, while both parachute and anchor techniques are equally effective for long-term functional maturation and overall complication rates.

Comparison between the 0- and 30-s balloon dilation time in percutaneous transluminal angioplasty for restenosed arteriovenous fistula among hemodialysis patients: a multicenter, prospective, randomized trial (CARP study)

BACKGROUND

This study aims to compare patency rates of the 0- and 30-s (sec) balloon dilation time in hemodialysis (HD) patients with restenosis after percutaneous transluminal angioplasty (PTA).

METHODS

The patients who underwent PTA within 6 months for failed arteriovenous fistula at the forearm were randomly assigned the 0-s or 30-s dilation time group. Effect of dilation time on the 3- and 6-month patency rates after PTA was examined.

RESULTS

Fifty patients were enrolled in this study. The 3-month patency rate in the 30-s dilation group was better than that in the 0-s dilation group (P = 0.0050), while the 6-month patency rates did not show a significant difference between the two groups (P = 0.28). Cox's proportional hazard model revealed that 30-s of inflation time (hazard ratio 0.027; P = 0.0072), diameter of the proximal (hazard ratio 0.32; P = 0.031), and dilation pressure (hazard ratio 0.63; P = 0.014) were associated with better 3-month patency. Dilation pressure between previous and present PTA did not differ in the 0-s (P = 0.15) and 30-s dilation groups (P = 0.16). The 6-month patency rate of the present PTA in the 30-s dilation group was higher than that of the previous PTA (P = 0.015). The visual analog scale did not differ between the two groups (P = 0.51).

CONCLUSION

The presenting data suggest that 30-s dilation potentially results in a better 3-month patency rate than 0-s dilation in HD patients with restenosis after PTA.

Out-Patient versus In-Patient Arteriovenous Fistula Creation for Dialysis: Assessing Cost-Effectiveness Alongside Clinical Implications

(1) Background: The surgical procedure to create an arteriovenous fistula (AVF) can be performed in either an ambulatory or in-patient hospital setting, depending on the case's complexity, the anesthesia type used, and the patient's comorbidities. The main scope of this study is to assess the cost-effectiveness and clinical implications of surgically creating an AVF in both ambulatory and in-hospital settings. (2) Methods: We conducted a retrospective observational study, in which we initially enrolled all patients with end-stage kidney disease (ESKD) admitted to the Vascular Surgery Department, Emergency County Hospital of Targu Mures, Romania, to surgically create an AVF for dialysis, between January 2020 and December 2022. The primary endpoint of this study is to assess the cost-effectiveness of surgically creating an AVF in an ambulatory vs. in-hospital setting by comparing the costs required for the two types of admissions. Further, the 116 patients enrolled in this study were divided into two groups based on their preference for hospitalization: out-patients and in-patients. (3) Results: Regarding in-patient comorbidities, there was a higher prevalence of peripheral artery disease (PAD) (p = 0.006), malignancy (p = 0.020), and previous myocardial infarction (p = 0.012). In addition, active smoking (p = 0.006) and obesity (p = 0.018) were more frequent among these patients. Regarding the laboratory data, the in-patients had lower levels of white blood cells (WBC) (p = 0.004), neutrophils count (p = 0.025), lymphocytes (p = 0.034), and monocytes (p = 0.032), but there were no differences between the two groups regarding the systemic inflammatory biomarkers or the AVF type. Additionally, we did not register any difference regarding the outcomes: local complications (p = 0.588), maturation failure (p = 0.267), and primary patency (p = 0.834). In our subsequent analysis, we discovered no significant difference between the hospitalization type chosen by patients regarding AVF primary patency failure (p = 0.195). We found no significant association between the hospitalization type and the recorded outcomes (all ps > 0.05) in both multivariate linear regression and Cox proportional hazard analysis. (4) Conclusions: In conclusion, there are no significant differences in the clinical implications, short-term and long-term complications of AVF for out-patient and in-patient admissions. Additionally, we found no variation in the costs associated with laboratory tests and surgical supplies for an AVF creation. Therefore, it is safe to perform ambulatory AVFs, which can reduce the risk of hospital-acquired infections and provide greater comfort to the patient.

Cost-effectiveness analysis of autogenous arteriovenous fistula, arteriovenous graft, and tunneled-cuffed catheter for hemodialysis in patients with end-stage kidney disease in Southern China

OBJECTIVES

To evaluate the cost-effectiveness of three permanent vascular accesses for maintenance hemodialysis patients from a hospital perspective throughout 5 years, which is the average life expectancy of patients with end-stage kidney disease.

SUBJECTS AND METHODS

We conducted a EuroQol(EQ-5D) questionnaire survey between January 2021 and March 2021 with 250 patients to estimate the health utility of various states in patients under different hemodialysis vascular access. We designed a Markov model and conducted a cost-effectiveness analysis to compare the cost-effectiveness of three hemodialysis vascular access in Guangzhou throughout 5 years.

RESULTS

The mean costs were US$44,481 with tunneled-cuffed catheter (TCC), and US$68,952 and US$59,247 with arteriovenous graft (AVG) and autogenous arteriovenous fistula (AVF), respectively. The mean quality-adjusted life-years (QALYs) was 1.41 with TCC, and 2.37 and 2.73 with AVG and AVF, respectively. AVG had an incremental cost-effectiveness ratio (ICER) of US$25,491 per QALY over TCC; AVF had an ICER of -US$26,958 per QALY over AVG. At a willingness to pay below US$10,633.8 per QALY, TCC is likely the most cost-effective vascular access. At any willingness to pay between US$10,633.8 and US$30,901.4 per QALY, AVF is likely the most cost-effective vascular access.

CONCLUSION

These findings illustrate the value of AVF given its relative cost-effectiveness to other hemodialysis modalities. Although AVG costs much more than TCC for slightly higher QALYs than TCC, AVG still has a greater advantage over TCC for patients with longer life expectancy due to its lower probability of death.

A systematic review of prediction models on arteriovenous fistula: Risk scores and machine learning approaches

OBJECTIVE

Failure-to-mature and early stenosis remains the Achille's heel of hemodialysis arteriovenous fistula (AVF) creation. The maturation and patency of an AVF can be influenced by a variety of demographic, comorbidity, and anatomical factors. This study aims to review the prediction models of AVF maturation and patency with various risk scores and machine learning models.

DATA SOURCES AND REVIEW METHODS

Literature search was performed on PubMed, Scopus, and Embase to identify eligible articles. The quality of the studies was assessed using the Prediction model Risk Of Bias ASsessment (PROBAST) Tool. The performance (discrimination and calibration) of the included studies were extracted.

RESULTS

Fourteen studies (seven studies used risk score approaches; seven studies used machine learning approaches) were included in the review. Among them, 12 studies were rated as high or unclear "risk of bias." Six studies were rated as high concern or unclear for "applicability." C-statistics (Model discrimination metric) was reported in five studies using risk score approach (0.70-0.886) and three utilized machine learning methods (0.80-0.85). Model calibration was reported in three studies. Failure-to-mature risk score developed by one of the studies has been externally validated in three different patient populations, however the model discrimination degraded significantly (C-statistics: 0.519-0.53).

CONCLUSION

The performance of existing predictive models for AVF maturation/patency is underreported. They showed satisfactory performance in their own study population. However, there was high risk of bias in methodology used to build some of the models. The reviewed models also lack external validation or had reduced performance in external cohort.

The hand grip training device: A new therapeutic option in arteriovenous fistula maturation

INTRODUCTION

Postoperative exercise improves arteriovenous fistula maturation for hemodialysis. However, scarce evidence exists about hand grip device on fistula maturation process.

OBJECTIVE

To evaluate the efficacy of a hand grip training program on arteriovenous fistula maturation in population with Chronic Kidney Disease 5-5D.

METHODOLOGY

Prospective study (15 months). Patients were randomized to handgrip (HG) or control group (CG) postoperatively. HG performed a training program using a hand grip device. CG received conventional care. Upper limb muscle strength (ULMS), Duplex ultrasonography, and clinical arteriovenous fistula maturation were assessed at 4 and 8 weeks postoperatively.

RESULTS

At 8 weeks after fistula creation, upper limb muscle strength was increased only in the handgrip group (from 18 ± 6 to 23 ± 9 kg, p = 0.023). Clinical maturation was significantly greater in handgrip group versus control group, both at 4 weeks after intervention (62% vs 23%, p = 0.004) and at 8 weeks (65% vs 27%, p = 0.004). Similarly, the Doppler ultrasonography maturation rates were significantly greater in the HG, both at 4 weeks (HG: 84% vs CG: 47%; p = 0.004) and at 8 weeks (HG: 89% vs CG: 50%; p = 0.002).

CONCLUSIONS

The hand grip is a useful and safety training device to improve the arteriovenous fistula maturation. This device results a new therapeutic option for maturation in arteriovenous fistula, particularly in distal arteriovenous fistula. Further studies are required to support these results.

Fully no-touch technique without inflating the cephalic vein increase the patency rate of arteriovenous fistulas

INTRODUCTION

One of the most important problems for patients undergoing hemodialysis due to chronic renal failure is the need for a long-lasting vascular access. The patency of vascular access is affected by many factors. Factors related to surgery are also among these factors. No-touch techniques theoretically and practically prevent endothelial damage due to minimal contact on vascular structures. It is a well-known fact that surgeries performed with these methods also increase long-term survival.

METHODS

Patients who underwent distal radiocephalic arteriovenous fistula (AVF) surgery for the first time between 2017 and 2021 were included in our study. The groups, whose cephalic veins were inflated conventionally and not inflated, were compared in a prospective randomized manner.

RESULTS

There was a significant difference between both groups in terms of failure and patency rates, which is one of the study endpoints (p = 0.012). The fact that the patency period is long, and the failure rate is low stands out as the superiority of the fully no-touch technique in AVF surgery. On the other hand, no significant difference was observed in terms of failure to maturation and fistula maturation time.

CONCLUSIONS

Fully no-touch technique in AVF surgery should be considered primarily in suitable patients due to its long patency time and low failure rate.

Elevated plasma leptin levels are associated with vascular access dysfunction in patients on maintenance hemodialysis

BACKGROUND

Inflammation has been associated with vascular access (VA) dysfunction. The adipocytokine leptin can directly induce pro-inflammatory T helper 1 immune responses and the pathogenesis of chronic inflammation. We explored the association between plasma leptin and VA dysfunction in patients on maintenance hemodialysis (HEMO).

METHODS

A total of 344 consecutive patients who received anastomosis for VA at a single HEMO center between June 1, 2010 and December 31, 2021 were screened. Of these patients, 267 met the inclusion criteria and were included. ELISA was used to measure circulating levels of leptin.

RESULTS

The VA dysfunction group had a higher leptin level than the patent VA group. A higher concentration of leptin was independently and significantly associated with an elevated risk of VA dysfunction. Multiple logistic regression analysis showed that leptin, female sex, and hypertension were independently associated with VA dysfunction, even after adjusting for known biomarkers. We then evaluated the ability of leptin, female sex, and hypertension to predict the risk of VA dysfunction, and the area under the curve (AUC) for leptin was 0.626 (p = 0.0001). When leptin, female sex, and hypertension were added to this multivariate model, the AUC increased to 0.679 (p = 0.001) for leptin and hypertension, and 0.690 for leptin, hypertension, and female sex (p = 0.004). In addition, plasma leptin levels were associated with sex, body mass index, and hemoglobin.

CONCLUSIONS

In addition to the association between leptin and VA dysfunction, hypertension and female sex independently predicted VA dysfunction in patients with HEMO.

The Role of Ultrasound Examination in the Assessment of Suitability of Calcified Arteries for Vascular Access Creation-Mini Review

Arterial calcifications are present in 20-40% of patients with end-stage kidney disease and are more frequent among the elderly and diabetics. They reduce the possibility of arterio-venous fistula (AVF) formation and maturation and increase the likelihood of complications, especially distal ischemia. This review focuses on methods for detecting arterial calcifications and assessing the suitability of calcified arteries for providing inflow before the construction of an AVF. The importance of a clinical examination is stressed. A grading system is proposed for quantifying the severity of calcifications in the arteries of the arm with B-mode and Doppler ultrasound exams. Functional tests to assess the suitability of the artery to provide adequate inflow to the AVF are discussed, including Doppler indices (peak systolic velocity and resistive index during reactive hyperemia). Possible predictors of the development of distal ischemia are discussed (finger pressure, digital brachial index, acceleration and acceleration time), as well as the outcomes of AVFs placed on calcified arteries. It is concluded that a noninvasive ultrasound examination is probably the best tool for a morphologic and functional assessment of the arteries. An arterial assessment is of utmost importance if we are to create distal radiocephalic AVFs in our elderly patients whenever possible without burdening them with futile surgical attempts.

Mid-term cumulative patency of fistula and PTFE grafts among hemodialysis patients: A retrospective, single-center study from Palestine

BACKGROUND

Due to the long waiting time for kidney transplantation, most End-Stage renal disease patients are commenced on either hemodialysis or peritoneal dialysis. Reusable fistulas have the lowest risk for death, cardiovascular events, and infections among all vascular accesses. This study aims to report the outcomes of the arteriovenous fistulas and PTFE grafts and the related predictive clinical and demographic variables.

METHODS

This retrospective study reviewed the charts of all hemodialysis patients between January 2017 and January 2021 at the Dialysis Center of An-Najah National University Hospital, Nablus, Palestine. Our outcomes were a primary failure, primary and secondary patency, and the related factors. Survival analysis using the Kaplan-Meier method was conducted, and the log-rank test was used to compare patency rates. The Cox proportional hazards regression model tested factors relevant to primary and secondary patency rates in univariate and multivariate analyses.

RESULTS

A total of 312 procedures were performed during the study period. Primary failure was 7.1% for AVF, 13.9% for arterio-venous graft (AVG) procedures. Peripheral arterial disease and left-sided AVF were associated with more primary failure rates. AVF, primary patency rates at 1, 2, and 3 years were 82%, 69%, and 59%, respectively, while secondary patency rates at 1, 2, and 3 years were 85%, 72%, and 63%, respectively. Factors associated with increased AVF patency in a proportional hazard model were younger age and dual antiplatelet administration.

CONCLUSION

Our study adds further evidence that autogenous AVF has better results than prosthetic AVG in both primary and secondary patency rates as well as less primary failure rates. Therefore, we encourage further longitudinal studies that assess the benefits of using antiplatelet on AVF outcome versus risks of bleeding, especially with dual agents.

Preoperative assessment for vascular access: Vascular mapping and handgrip strength

BACKGROUND

Reliable vascular access (VA) is required for patients receiving chronic hemodialysis (HD) treatment. Vascular mapping using duplex doppler ultrasonography (DUS) can aid in planning VA construction. Greater handgrip strength (HGS) was found to be associated with more developed distal vessels both in chronic kidney disease (CKD) patients and healthy individuals, and patients with lower HGS had worse morphologic vessel characteristics and were, therefore, less likely to construct distal VA.

OBJECTIVES

This study aims to describe and analyze clinical, anthropometric, and laboratory characteristics of patients who underwent vascular mapping prior to VA creation.

RESEARCH DESIGN

Prospective analysis.

SUBJECTS

Adult patients with CKD referred for vascular mapping, at a tertiary center, between March 2021 and August 2021.

MEASURES

Preoperative DUS by a single experienced nephrologist was carried out. HGS was measured using a hand dynamometer, and PAD was defined as ABI < 0.9. Sub-groups were analyzed according to distal vasculature size (<2 mm).

RESULTS

A total of 80 patients were included, with a mean age of 65.7 ± 14.7 years; 67.5% were male, and 51.3% were on renal replacement therapy (RRT). Twelve (15%) participants had PAD. HGS was higher in the dominant arm (20.5 ± 12.0 vs 18.8 ± 11.2 kg). Fifty-eight (72.5%) patients had vessels smaller than 2 mm in diameter. There were no significant differences between groups concerning demographics or comorbidities (diabetes, HTN, PAD). HGS was significantly higher in patients with distal vasculature greater than or equal to 2 mm in diameter (dominant arm: 26.1 ± 15.5 vs 18.4 ± 9.7 kg, p = 0.010; non-dominant arm: 24.1 ± 15.3 vs 16.8 ± 8.6, p = 0.008).

CONCLUSIONS

Higher HGS was associated with more developed distal cephalic vein and radial artery. Low HGS might be an indirect sign of suboptimal vascular characteristics, which might help predict the outcomes of VA creation and maturation.

Patency Rates and Outcomes of Renal Access Arteriovenous Fistulas for Hemodialysis in Patients with Chronic Kidney Disease

Hemodialysis remains the most popular modality of renal replacement therapy for end-stage renal disease patients with chronic kidney disease. Various factors such as a radial artery, cephalic vein diameter, age, hypertension, and diabetes mellitus can affect the fistula maturation. This study was carried out to know the patency rates and factors affecting fistula maturation in the Indian population. This is a prospective observational study which aimed to study the patency rate of arteriovenous (AV) fistulas. On the day of surgery, patients were shifted inside the operation theater. Under all aseptic precautions, an AV fistula was formed using the radial artery and cephalic vein. All patients were followed up for 6 months. The data were analyzed using IBM SPSS version 22. To see the change over a period of time, McNemar test for categorical data and repeated measure for continuous data followed by post hoc comparison by Bonferroni method were used. The mean age of the patients was 46.98 ± 13.33 years. The mean diameter of the cephalic vein, ulnar artery, and radial artery at the wrist was 1.733 ± 0.528, 1.700 ± 0.364, and 1.908 ± 0.420, respectively, whereas the mean diameter of the cephalic vein, ulnar artery, and radial artery at the forearm was 1.952 ± 0.488, 1.910 ± 0.421, and 2.058 ± 0.458, respectively. Immediate thrill after the surgery was present in 36/52 (69.2%) of the patients. The radial artery diameter at the wrist was significantly less in the patients with primary failure in whom immediate thrill was not present (P = 0.016). At 1-month follow-up, 30/49 (61.2%) and, at 6 months, 29/48 (60.4%) fistulas were functional. Radiocephalic AV fistulas have a reasonable success rate and minimal morbidity, and radial artery diameter is a good predictor of the outcome.

Reassessing the utility of access recirculation and Kt/V for the prediction of arteriovenous fistula failure using online clearance monitoring: the SHUNT STUDY

BACKGROUND

The arteriovenous fistula (AVF) is prone to thrombosis which can be avoided by use of monitoring and surveillance programmes. Although surveillance imaging techniques have been shown to be more sensitive and specific than clinical monitoring during dialysis, monitoring may have significant advantages in terms of cost and time saving. In this study we evaluate the yield of two monitoring techniques [blood temperature monitoring (BTM) access recirculation (AR) and Kt/V via online-clearance-monitoring (OCM)].

METHODS

In this single-centre prospective observational study, 101 patients were followed-up for one year. The primary outcome measure was a composite of AVF failure. OCM-Kt/V and BTM-AR were recorded at every dialysis session.

RESULTS

Of all baseline characteristics only a prior history of percutaneous transluminal angioplasty (PTA) to the AVF conferred a significant change in AVF survival (failure events/100 pt years with prior PTA vs. without = 64.0 vs. 17.3, log-rank p = 0.0014; unadjusted hazard ratio (HR) 3.74 (95% CI 1.56-8.94) p = 0.003). Participants with baseline AR < 10% vs. > 15% had poorer AVF survival (p = 0.0002) and HR for baseline AR 10-15% group vs. AR > 15% group = 4.5 (95% CI 1.55-13.05). There was no combination of change in (Δ) AR, ΔKt/V or its presence over any number of dialysis sessions that provided an acceptable combination of sensitivity and specificity or discrimination for AVF failure.

CONCLUSIONS

BTM-AR and OCM-Kt/V are specific but insufficiently sensitive tools for the prediction of AVF failure. BTM-AR and OCM-Kt/V use at every dialysis session appears to add little to the traditional, infrequent use of these evaluations.

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.

Oxidative stress: An essential factor in the process of arteriovenous fistula failure

For more than half a century, arteriovenous fistula (AVFs) has been recognized as a lifeline for patients requiring hemodialysis (HD). With its higher long-term patency rate and lower probability of complications, AVF is strongly recommended by guidelines in different areas as the first choice for vascular access for HD patients, and its proportion of application is gradually increasing. Despite technological improvements and advances in the standards of postoperative care, many deficiencies are still encountered in the use of AVF related to its high incidence of failure due to unsuccessful maturation to adequately support HD and the development of neointimal hyperplasia (NIH), which narrows the AVF lumen. AVF failure is linked to the activation and migration of vascular cells and the remodeling of the extracellular matrix, where complex interactions between cytokines, adhesion molecules, and inflammatory mediators lead to poor adaptive remodeling. Oxidative stress also plays a vital role in AVF failure, and a growing amount of data suggest a link between AVF failure and oxidative stress. In this review, we summarize the present understanding of the pathophysiology of AVF failure. Furthermore, we focus on the relation between oxidative stress and AVF dysfunction. Finally, we discuss potential therapies for addressing AVF failure based on targeting oxidative stress.

Contact Laxative Use and the Risk of Arteriovenous Fistula Maturation Failure in Patients Undergoing Hemodialysis: A Multi-Center Cohort Study

Laxatives are commonly prescribed for constipation management; however, they are recognized as an independent factor associated with cardiovascular diseases. Arteriovenous fistula (AVF) is the closest to the ideal model of hemodialysis (HD) vascular access and part of the cardiovascular system. Our study aims to explore the association of contact laxative use with AVF maturation outcomes in patients undergoing HD. We conducted a multi-center cohort study of 480 contact laxative users and 472 non-users who had undergone initial AVF creation. All patients were followed until the outcomes of AVF maturation were confirmed. Multivariable logistic regression models were performed to evaluate the risk of AVF maturation failure imposed by laxatives. Here, we found that patients who used contact laxatives were significantly associated with an increased risk of AVF maturation failure compared to non-users (adjusted odds ratio, 1.64; p = 0.003). Notably, the risk of AVF maturation failure increased when increasing their average daily doses and cumulative treatment days. In conclusion, our study found a significant dose- and duration-dependent relationship between contact laxative use and an increased risk of AVF maturation failure. Thus, laxatives should be prescribed with caution in this population. Further studies are needed to validate these observations and investigate the potential mechanisms.

Preoperative Cardiac Index as a Predictor of Maturation and Primary Patency of Radiocephalic Arteriovenous Fistula in Hemodialysis

BACKGROUND

Radiocephalic arteriovenous fistula (RCAVF) is the best access modality to be considered initially when planning arteriovenous fistula (AVF) for maintenance hemodialysis. Considering the higher incidence of RCAVF failed maturation (M), it is important to perform proper preoperative evaluation and identification of high-risk patients. There has been no study on the influence of preoperative cardiac function on the M and patency of AVFs. The purpose of this investigation is to determine whether preoperative cardiac index (CI) is a predictor of M and primary patency of RCAVF.

METHOD

A total of 365 end-stage renal disease patients undergoing RCAVF surgery were consecutively enrolled with a median follow-up time of 20 months in this prospective cohort study. Demographics, vascular diameters measured by duplex ultrasound examination, and CI measured by echocardiography, were analyzed for effect on RCAVF primary functional M and primary patency.

RESULT

Patients in the group achieving primary RCAVF functional M had a significantly larger mean CI than the group with early RCAVF failure (2.93 ± 0.77 vs. 3.57 ± 0.76 L/min/m2, p < 0.001). The receiver operating characteristic curve was plotted and demonstrated that preoperative vein diameter and CI can predict failure of RCAVF M. The AUC of CI was higher (0.745 vs. 0.666). Multivariate regression analysis, adjusted for age, sex, diabetes, preoperative dialysis status and vessel diameters, showed that decreased CI remained associated with increased risk of failure of M (FM) and worse primary unassisted patency. The Kaplan-Meier survival analysis suggested that patients with CI <3 L/min/m2 had a worse primary unassisted patency rate at all time points compared with patients with CI ≥3 L/min/m2.

CONCLUSION

This study demonstrated that preoperative CI was associated with RCAVF M and long-term patency. A decreased CI may be a possible predictor of an increased risk of FM and a shorter primary patency time.

Evolutive profile of hemodialysis vascular accesses Hemodialysis accesses

INTRODUCTION

Arterio-venous fistula (AVF) is the first-choice vascular access for hemodialysis (HD). Hemodialysis catheter (KT) may be a temporary or permanent alternative.

AIM

To evaluate indications of KT and AVF and their predictive factors of complications.

METHODS

It's a retrospective multicentric study interesting KT and AVF in patients treated by hemodialysis, in the Kef Governorate in north-western Tunisia, during the period from 01/07/18 to 31/12/18.

RESULTS

We included 288 AVF and 148 KT that were created on 205 patients. The average age was 58.14 years, the sex ratio was 1.5. Hypertensive patients and diabetics represented respectively 83.9% and 27.3% of the population. Diabetic nephropathy was the most common (25.9%). For the KT, the main indication was the wait for AVF creation (68.9%). The overall incidence of immediate complications was 11.5%. Dysfunction was reported in 23.6% of cases with obesity and tunneled type of KT as contributing factors. KT infection was occuring in 39.2% of cases. It was promoted by prolonged duration of use and hemoglobin level < 8g/dl. The use of antiseptic lock reduced infections' risk (p=0.011). For AVF, the most common complications were thrombosis (36.2%), aneurysm (29.9%) and stenosis (22.6%). Survival rate was 60% at 2000 days. The AVF impairing factors were diabetes (p=0.05), obesity (p=0.05), anterior AVF creation (p=0.011), AVF grafts (p=0.016), and anticoagulant therapy (p=0.0001). Antiplatelet therapy improved AVF patency (p=0.02).

CONCLUSION

Much remained to be done to reduce KT complications, creation of AVF on time and prevention of their complications.

A cost-effectiveness analysis of the introduction of a specialised consultation with duplex ultrasound assessment prior to vascular access surgery for haemodialysis

INTRODUCTION

Duplex ultrasound (DUS) is increasingly used before vascular access (VA) surgery for haemodialysis. However, the cost-effectiveness of this approach is unknown. Our objective was to assess whether the introduction of a specialised consultation with DUS assessment modifies the cost and the time delay to achieve a first VA valid for haemodialysis.

PATIENTS AND METHODS

Prospective cohort of patients undergoing a first VA (June 2014-July 2017) after a specialised consultation with DUS (ECO group). They were compared with a historical cohort (January 2012-May 2014) where VA was indicated exclusively by clinical evaluation (CLN group). We analysed the cost related to visits, DUS assessments, interventions, hospital admissions and graft materials to achieve a first VA valid for haemodialysis at least during 1 month.

RESULTS

86 patients in the CLN group were compared with 92 in the ECO group. Patients in the ECO group were younger (68.4 vs. 64.0 years; P=.038) but no other differences were seen among groups. The average cost to achieve a first AV valid for haemodialysis was significantly lower in the ECO group (2707 vs. 3347€; P=.024). There was a higher cost associated with DUS assessments in the ECO group yet the CLN group had a higher cost related to follow-up visits, successive surgical interventions, prosthetic material, days of hospital admission and catheters. The mean time needed to achieve a first AV valid for haemodialysis was also shorter in the ECO group (49.9 vs. 82.9 days, P=.002).

CONCLUSION

The introduction of a specialised vascular access consultation with DUS prior to VA surgery has reduced the cost necessary to achieve a first VA valid for haemodialysis. From the patient's point of view this has meant less interventions and hospital admissions and a shortening of the time delay.

Long-term outcomes of arteriovenous snuffbox fistulas for hemodialysis

OBJECTIVE

Autologous arteriovenous fistulas in the arm have been shown to be superior to all other types of arteriovenous access and should be placed as far distally as possible. The aim of the present study was to delineate the advantages of snuffbox fistulas (SBFs).

METHODS

From January 2007 through April 2017, first time or new arteriovenous fistula surgery was performed in 375 patients. If feasible, an SBF was chosen. The observation period ended in December 2019. The focus of the present study was on the patency rates, redo surgery, complications, and mortality rates.

RESULTS

SBFs were created in 236 patients (92 women and 144 men; mean age, 67 years; 46% with diabetes). Within the first 6 weeks, 11% of the fistulas had failed. The primary patency rates were 75%, 69%, 64%, 61%, 60%, and 58% after 1, 2, 3, 5, 7, and 9 years, respectively. The secondary patency rates were 86%, 83%, 80%, and 77% after 1, 2, 3, and 5 years, respectively. Age, sex, and the presence of diabetes mellitus had no effect on the primary patency rates. Patients with a right-sided SBF had significantly worse primary patency. Of the 236 patients, 154 (65%) had died during the observation period. The incidence of surgical site infection within the first 30 days and access-related ischemia during the observation period was <1%.

CONCLUSIONS

The results from the present study have shown that with suitable anatomic conditions, a SBF is a good choice for the creation of dialysis access. The patency rates were encouraging, and it offers the longest puncturable segment of the cephalic vein. Also, the rate of perioperative complications was low.

Vessel diameter and close surveillance helps predict early patency in native arteriovenous fistulas

INTRODUCTION

Arteriovenous fistulas are the preferred method of vascular access for haemodialysis. Data suggests patency rates can be low and may be related to vessel diameters prior to creation. We use specific size criteria for fistula selection. We aimed to establish patency rates in relation to vessel size and whether other factors affect fistula patency.

METHODS

Consecutive patients undergoing radiocephalic (RCF) or brachiocephalic (BCF) creation between 2016 and 2018 were analysed. Preoperative arterial and venous diameters were collected. Six-week and six-month primary and secondary patency rates were analysed to establish any impact of vessel size on patency and re-intervention rates between groups. A univariate analysis was performed.

RESULTS

Ninety four RCFs and 101 BCFs were created. Median artery and vein size for RCF were 2.7 and 3.0 mm respectively. For BCF, they were 4.6 and 4.3 mm respectively. At 6-weeks, overall satisfactory patency for RCF and BCF combined was 91.8%. 89.7% demonstrated primary patency; 2.1% secondary patency. At 6-months, overall patency was 78.7%; 58.5% demonstrated primary patency, 20.2% secondary patency. A univariate analysis, for both groups, revealed vein size was a significant predictor of overall satisfactory patency at 6-weeks, with larger veins more likely to remain patent (p = 0.025 RCF, p = 0.007 BCF). However, artery size was not predictive (p = 0.1 RCF, p = 0.5 BCF). At 6-months, neither artery nor vein diameter were predictive in either group. When comparing size of vessel based on fistula type, vessels used to create RCFs were smaller than those for BCFs (p < 0.001). RCFs were more likely to receive endovascular intervention or occlude when compared to BCFs (p = 0.014).

DISCUSSION

Excellent patency and maturation rates can be achieved using fairly strict vessel size criteria. Vein size might be the more important predictor of early success. RCFs can be challenging due to smaller vessels, but maturation rates can be optimised by close surveillance and aggressive re-intervention.

Vasodilator agents improve hemodialysis vascular access patency: A population-based study from Korea

Vascular access (VA) failure is an important problem for patients undergoing hemodialysis, and maintaining VA patency is challenging. In this study, we used a nationwide database to investigate the effects of nitrate, as a vasodilator, on VA failure in hemodialysis patients.We investigated the Korean insurance claims data of hemodialysis patients who underwent angioplasty for VA failure between January 2012 and December 2017. The patients were divided into 2 groups: those not receiving vasodilator therapy (controls) and those receiving any vasodilator administration (vasodilator treatment, VDT). The primary endpoint was VA primary patency, defined as the time between arteriovenous dialysis access creation and the first percutaneous transluminal angioplasty (PTA).During the study period, a total of 6350 patients were recruited, 409 (6.4%) patients assigned to the VDT group and 5941 (93.6%) controls. PTA was performed in 998 patients (15.7%), including 8 in the VDT group and 990 controls. The VA site PTA rate was significantly lower in the VDT group (2.0%) than in the control group (16.7%, P < .001). In the subgroup analysis, the patency rates associated with the different vasodilators were similar (P = .736). All vasodilators, except molsidomine, improved the patency rate by approximately 20%.In this large national database study, vasodilator administration was associated with higher VA primary patency, compared with controls, in hemodialysis patients. VDT may have a beneficial effect on maintaining VA patency in patients undergoing hemodialysis.

Upper limb anatomy and preoperative mapping

Vascular access is absolutely essential for haemodialysis due to its relationship with quality of dialysis and associated morbidity. Therefore, it must be monitored and continuously surveilled from the moment it is created to prevent failure in maturation and thrombosis. Multidisciplinary collaboration is necessary when the main aim is to achieve the adequate vascular access flow with the fewest possible complications. The starting point, and probably the main one, is vascular access planning. This planning requires both a deep understanding of the anatomy of the upper limb and enough skill to examine it by Doppler ultrasound. The aim of this article is to review the anatomical and haemodynamical concepts of the arterial and venous vascular tree and explain how to perform ultrasound mapping, optimising the technical resources provided by this tool. Likewise, adequate access creation criteria that minimise the risk of failure and associated complications will be discussed.

Plasmatic osteopontin and vascular access dysfunction in hemodialysis patients: a cross-sectional, case-control study (The OSMOSIS Study)

BACKGROUND AND AIMS

Despite close follow-up of patients with native arteriovenous fistulas (AVFs), up to 10% experience thrombosis each year. The OSMOSIS Study (Osteopontin as a Marker of Stenosis) tested the hypothesis that the systemic osteopontin level, a pro-inflammatory mediator related to vascular remodelling and intimal hyperplasia, increases in AVF stenosis, and may be used in clinical surveillance.

METHODS

Our cross-sectional study compared the level of plasmatic osteopontin (pOPN) between patients with a well-functioning AVF (control group) and patients who required revision of their AVF due to stenosis (stenosis group). Blood samples were collected before dialysis (control group) or before intervention (stenosis group) from the AVF arm, and from the opposite arm as a within-subject control. pOPN level was measured by enzyme-linked immunosorbent assay.

RESULTS

A total of 76 patients were included in the study. Baseline characteristics were similar between the groups (mean age, 70 years; men, 63%; AVF duration, 39 months), apart from prevalence of type 2 diabetes (T2D) (control group, 33%; stenosis group, 57%; p = 0.04). pOPN levels were similar between the AVF arm and the contralateral arm (551 ± 42 ng/mL vs. 521 ± 41 ng/mL, respectively, p = 0.11, paired t-test). Patients in the stenosis group displayed a higher pOPN level than patients in the control group (650.2 ± 59.8 ng/mL vs. 460.5 ± 61.2, respectively, p = 0.03; two-way ANOVA). T2D was not identified as an associated factor in a multivariate analysis (p = 0.50).

CONCLUSIONS

The level of pOPN in hemodialysis patients was associated with the presence of AVF stenosis requiring intervention. Thus, its potential as a diagnostic biomarker should be assessed in a vascular access surveillance program.

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 far infrared therapy on arteriovenous fistula maturation, survival and stenosis in hemodialysis patients, a randomized, controlled clinical trial: the FAITH on fistula trial

BACKGROUND

An arteriovenous fistula (AVF) is the preferred vascular access for hemodialysis treatment. After creation many of the AVFs will never mature or if functioning will need an intervention within 1 year due to an AVF stenosis. Studies investigating possible therapies that improves the AVF maturation and survival are scarce. Far infrared therapy (FIR) has shown promising results. In minor single centre and industry supported trials FIR has shown improved AVF maturation and survival. There is a need of a randomized multicentre controlled trial to examine the effect of FIR on the AVF maturation and survival and to explore the possible AVF protective mechanism induced by the FIR treatment.

METHODS

This investigator initiated, randomized, controlled, open-labeled, multicenter clinical trial will examine the effect of FIR on AVF maturation in patients with a newly created AVF (incident) and AVF patency rate after 1 year of treatment in patients with an existing AVF (prevalent) compared to a control group. The intervention group will receive FIR to the skin above their AVF three times a week for 1 year. The control group will be observed without any treatment. The primary outcome for incident AVFs is the time from surgically creation of the AVF to successful cannulation. The primary outcome for the prevalent AVFs is the difference in number of AVFs without intervention and still functioning in the treatment and control group after 12 months. Furthermore, the acute changes in inflammatory and vasodilating factors during FIR will be explored. Arterial stiffness as a marker of long term AVF patency will also be examined.

DISCUSSION

FIR is a promising new treatment modality that may potentially lead to improved AVF maturation and survival. This randomized controlled open-labelled trial will investigate the effect of FIR and its possible mechanisms.

TRIAL REGISTRATION

Clinicaltrialsgov NCT04011072 (7th of July 2019).

Factors influencing arteriovenous fistulas: A multicenter study

In this cross-sectional, descriptive study, the arteriovenous fistulas (AVF) of HD patients were evaluated by physical examination and factors associated with AVF function and longevity were investigated. Data were collected using a patient information form and the Arteriovenous Fistula Assessment Scale (AVF-AS). The study population included 279 patients under chronic HD treatment. Their mean age was 61.14 ± 14.00 years and 58.6% were men. Age, AVF location, and number of AVFs created were identified as factors associated with AVF needle entry site and flow problems, stenosis, and risk of developing ischemic complications (p = 0.005, p = 0.000, p = 0.006, respectively). AVF dysfunction adversely affected HD pump speed (p = 0.000) and HD adequacy (p = 0.000). It was determined that gender, AVF location, last AVF duration, and total number of previous AVF were identified as the risk of AVF complications. The results of this study revealed that regular follow-up and evaluation are needed to minimize the risk of dysfunction and failure due to AVF complications.

Can We Create an Arteriovenous Fistula for Hemodialysis through 0.5-1.0 cm Incision without Using Vascular Clamps?

Background A native arteriovenous fistula (AVF) is a gold standard for renal replacement therapy, where regular hemodialysis is the mainstay of survival in the majority of patients suffering from end-stage renal disease. Appropriate vascular clamps are routinely used to occlude an artery and a vein before an arteriotomy or a venotomy is done to prevent blood loss and have a clear field and an ease of anastomosis. The title makes one wonder, is it then possible to create an AVF without using vascular clamps? And through incisions as small as 0.5to 1.0 cm? This is made possible by a very simple new technique, presented here, that helps to occlude vessels to create an AVF through minimal access, and minimize blood loss and postoperative pain.

Material and Method  Total 622 AVFs were created between 1998 and 2019. With regular forceps or an AVF platform (design given), an AVF was created without using a vascular clamp. Total 321 cases were operated with 0.5 to 1.0 cm and 215 cases within 1.5 cm skin incision approach.

Results  There were ~85% successful functional fistulas. The blood loss was negligible, and only one in three required pain killer in postoperative period.

Conclusion  A simple new technique described here makes it possible to create a functional AVF through a small incision, without using vascular clamps.

Comparison of one-year patency rates of end-to-side and side-to-side anastomosis technique in proximal forearm region radial-cephalic fistulas

OBJECTIVES

In this study, the effects of anastomosis techniques on the results of patients with autogenous radial-cephalic proximal forearm fistula were investigated.

METHODS

Patients who underwent radial-cephalic proximal forearm fistula surgery (arteriovenous fistula) between April 2015 and August 2017 at the Department of Cardiovascular Surgery of Ordu University were compared retrospectively in terms of the results of anastomosis techniques. The study included 131 patients who had arteriovenous fistulas created by side-to-side and end-to-side anastomosis technique.

RESULTS

There was no significant difference in demographic data, comorbidities, radial artery, and cephalic vein diameters in patients undergoing radial-cephalic proximal forearm fistula surgery. However, it was observed that fistula maturation was earlier in the group with end-to-side anastomosis technique, and the one-year patency rates were higher in the group with side-to-side anastomosis technique.

CONCLUSION

In Arteriovenous fistulas created in the proximal forearm region, the one-year patency rate of the side-to-side anastomosis technique was higher, while the maturation of the end-to-side technique observed earlier.

A cost-effectiveness analysis of the introduction of a specialised consultation with duplex ultrasound assessment prior to vascular access surgery for haemodialysis

INTRODUCTION

Duplex ultrasound (DUS) is increasingly used before vascular access (VA) surgery for haemodialysis. However, the cost-effectiveness of this approach is unknown. Our objective was to assess whether the introduction of a specialised consultation with DUS assessment modifies the cost and the time delay to achieve a first VA valid for haemodialysis.

PATIENTS AND METHODS

Prospective cohort of patients undergoing a first VA (June 2014-July 2017) after a specialised consultation with DUS (ECO group). They were compared with a historical cohort (January 2012-May 2014) where VA was indicated exclusively by clinical evaluation (CLN group). We analysed the cost related to visits, DUS assessments, interventions, hospital admissions and graft materials to achieve a first VA valid for haemodialysis at least during 1 month.

RESULTS

Eighty-six patients in the CLN group were compared with 92 in the ECO group. Patients in the ECO group were younger (68.4 vs. 64.0 years; P=.038) but no other differences were seen among groups. The average cost to achieve a first AV valid for haemodialysis was significantly lower in the ECO group (2707 vs. 3347€; P=.024). There was a higher cost associated with DUS assessments in the ECO group yet the CLN group had a higher cost related to follow-up visits, successive surgical interventions, prosthetic material, days of hospital admission and catheters. The mean time needed to achieve a first AV valid for haemodialysis was also shorter in the ECO group (49.9 vs. 82.9 days, P=.002).

CONCLUSION

The introduction of a specialised vascular access consultation with DUS prior to VA surgery has reduced the cost necessary to achieve a first VA valid for haemodialysis. From the patient's point of view this has meant less interventions and hospital admissions and a shortening of the time delay.

Association of early failure of arteriovenous fistula with mortality in hemodialysis patients

Arteriovenous fistula (AVF) is prone to early dysfunction and relates to poor outcome. However, little is known about the role of early AVF dysfunction as an independent risk factor for death in hemodialysis patients. A retrospective cohort study was performed using data of patients who underwent initial AVF surgery at a single institution. Demographic, clinical, biochemistry and AVF parameters were extracted from the electronic records, and the association between these variables and mortality was analyzed by Cox proportional hazards model. A total of 501 patients on hemodialysis (63.4 ± 12.7 years, 57.3% male) were included, and the median observation period was 3.66 years. In multivariate analysis, early failure of AVF (hazard ratio (95% confidence interval): 1.54 (1.06–2.24); p = 0.023) was associated with overall mortality but not cardiovascular mortality. Other identified predictors of overall mortality included older age, peripheral artery disease (PAD), cardiomegaly, higher white blood cell (WBC) count and corrected calcium level, and lower total cholesterol level, while predictors of cardiovascular mortality included older age, coronary artery disease (CAD), PAD and lower hemoglobin level. In conclusion, patients with early AVF failure were associated with increased risk of overall mortality.

Contemporary outcomes of a "snuffbox first" hemodialysis access approach in the United States

OBJECTIVE

The Society for Vascular Surgery guidelines for permanent hemodialysis (HD) access creation recommend prioritizing the most distal possible autogenous access to minimize complications and preserve more proximal options. The "snuffbox" arteriovenous fistula (AVF) is the most distal radial artery-cephalic vein AVF. Despite the theoretical benefits of the snuffbox approach, recent trends have been toward upper arm access. Our study sought to investigate the feasibility of a snuffbox-first strategy for HD access in all anatomically appropriate candidates.

METHODS

From January 2016 to August 2019, all patients with end-stage renal disease (ESRD) or pre-ESRD under consideration for HD access were evaluated for a snuffbox-first approach by a team of vascular surgeons and nephrologists at a single, urban academic medical center in the United States. Data were collected prospectively and supplemented by medical record review. A survival analysis was performed to evaluate primary unassisted and secondary patency and clinical and functional maturation. Patients were censored if they had received a kidney transplant or had died. Cox proportional hazards regression was used to determine the risk factors for prolonged clinical maturation and functional maturation.

RESULTS

A total of 55 snuffbox AVFs were created. The median patient age was 60 years (interquartile range [IQR], 52-70 years), and 52.7% of the patients were men. The median follow-up was 369 days (IQR, 166-509 days). The median survival for primary unassisted patency was 90 days (95% confidence interval [CI], 79-111). Secondary patency at 1 year was 92.3% (95% CI, 85.3%-99.9%). The clinical maturation rate at 1 year was 83.7% (n = 55; 95% CI, 66.8%-91.9%), and the functional maturation rate at 1 year was 85.6% (n = 40; 95% CI, 63.3%-94.4%). Of the patients who were pre-ESRD at AVF creation and had initiated HD during the study period, 87.5% had successfully received incident HD with their snuffbox AVF. Twenty-four patients were receiving HD via a catheter at snuffbox creation. Of those patients, the functional maturation rate at 1 year was 82.5% (95% CI, 44.8%-94.4%). The patients had undergone a median of two interventions (IQR, zero to seven interventions) in the first year. Of these, 46.9% were percutaneous angioplasty and 31.2% were side-branch ligation. Diabetes was associated with slower AVF clinical maturation (multivariate hazard ratio, 0.35; 95% CI, 0.15-0.82; P = .016). A larger artery diameter was associated with earlier AVF clinical maturation (multivariate hazard ratio, 6.64; 95% CI, 2.11-20.9).

CONCLUSIONS

A snuffbox-first approach to HD access is a viable option for distal access creation in a cohort of patients requiring HD in the United States. Subsequent ancillary interventions to facilitate access maturation were required for most patients.

Outcome of Permanent Vascular Access with Vein ≤ 2.2 mm in Diameter

OBJECTIVE

End-stage renal disease patients with vein diameter of ≤2.2 mm can undergo autogenous arteriovenous fistula (AVF) formation with the acceptable results.

METHODS

This observational retrospective study of prospectively collected data analyzed end-stage renal disease patients with a vein diameter of ≤ 2.2 mm, who underwent AVF formation at Shifa International Hospital Islamabad from January 2009 to December 2017. The fistulae were observed for immediate success and maturity at 3 months. The chi-square test was used to determine the effect of vein diameter on final maturity. All data were analyzed using SPSS.

RESULTS

The total number of patients with vein diameter of ≤2.2 mm was 38, with a mean age of 46.76 ± 12.790 years. Vein diameters ranged from 1.6 to 2.2 mm. Immediate success was observed in 35 (92.1%) cases. Veins of 31 (81.6%) patients showing maturity at 3 months and were used for hemodialysis. The overall success rate for the small caliber veins was 82%.

CONCLUSION

Although end-stage renal disease patients present late with very small diameter veins, these veins should still be accommodated for permanent vascular access, because their maturity rates are still acceptable, even though these are lower than those of patients with adequate sized veins.

The association of erythropoietin-stimulating agents and increased risk for AV-fistula dysfunction in hemodialysis patients. A retrospective analysis

BACKGROUND

Patients in maintenance hemodialysis (HD) need a patent vascular access for optimal treatment. The recommended first choice is a native arteriovenous fistula (AVF). Complications of AVF are frequent and include thrombosis, stenosis and infections leading to worsening of dialysis efficacy. Some known risk factors are age, gender and the presence of diabetes mellitus. The aim was to investigate if further risk variables are associated with dysfunctional AVF.

METHODS

This retrospective observational study included 153 chronic HD patients (Cases) referred to a total of 473 radiological investigations due to clinically suspected complications of their native AVF. Another group of chronic HD patients (n = 52) who had a native AVF but were without history of previous complications for at least 2 years were controls. Statistical analyses included ANOVA, logistic regression, parametric and non-parametric methods such as Student's T-test and Mann-Whitney test.

RESULTS

Among Cases, at least one significant stenosis (> 50% of the lumen) was detected in 348 occasions. Subsequent PTA was performed in 248 (71%). Median erythropoiesis-stimulating agent (ESA) weekly doses were higher in Cases than in Controls (8000 vs 5000 IU, p < 0.001). Cases received higher doses of intravenous iron/week than the Controls before the investigation (median 50 mg vs 25 mg, p = 0.004) and low molecular weight heparin (LMWH, p = 0.028). Compared to Controls, Cases had a lower level of parathyroid hormone (median 25 vs 20 ρmol/L, p = 0.009). In patients with diabetes mellitus, HbA1c was higher among Cases than Controls (50 vs 38 mmol/mol, p < 0.001). Multiple regression analysis revealed significant associations between Cases and female gender, prescription of doxazocin, and doses of ESA and LMWH. There was no difference between the groups regarding hemoglobin, CRP or ferritin.

CONCLUSION

In conclusion, the present study indicated that the factors associated with AVF problems were high doses of ESA, iron administration, and tendency of thromboembolism (indicated by high LMWH doses); the use of doxazocin prescription, however, requires further investigation.

Perceived barriers and attitudes toward arteriovenous fistula creation and use in hemodialysis patients in Palestine

In the dialysis center in Ramallah, we investigated the attitudes and perceived barriers to having arteriovenous fistula (AVF) in 156 patients. The current method of HD access was AVF in 52% and central venous catheter in 47%. Perceived causes of no or delayed AVF were: patient’s refusal of AVF in 54.5%, late referral to a surgical evaluation in 31.3% and too long to surgical appointments in 14.2%. Among those who refused AVF, reasons were: concern about the surgical procedure in 42.5%, poor understanding of disease/access in 23.3%, fear of needles in 15.1%, denial of disease or need for HD in 17.8%, and cosmetic reasons in 1.4%. Forty six percent of patients believed they received education about AVF prior to the creation of HD access, and 73.7% would recommend AVF as the method of access due to the lower risk of infection (96%), easier to care for (16%), easier showering (14%), and better-associated hygiene (3%). In conclusion, the majority would recommend an AVF as the mode of vascular access for HD. The most common barrier to having an AVF was patient’s refusal to undergo AVF creation because of their concern about the surgical procedure. A systematic evaluation of the process that precedes the creation of AVF may allow for better utilization.

Advanced kidney disease: What the nonnephrology NP needs to know

ABSTRACT

Nonnephrology NPs often encounter patients with advanced chronic kidney disease. As patients transition to nephrology care, NPs need to communicate with them about their disease status and treatment. This article describes the treatment approach in patients with advanced kidney disease including medical management, hemodialysis, peritoneal dialysis, and transplantation.

Transposition of brachiobasilic arteriovenous fistulas: One-stage or two-stage technique and factors affecting the early maturation

The brachiobasilic transposition (BBT) arteriovenous fistula (AVF) is a valuable option especially for dialysis patients with previously failed vascular access. We aim to report factors affecting the maturation of BBT-AVF created with either one-stage or two-stage technique. BBT-AVF procedures between January 2015 and May 2019 by a dedicated vascular access team were investigated retrospectively. A total of 122 patients (63 males, 59 females), with 6 to 12 weeks of follow-up after the BBT-AVF procedure were included in the study. Patients of one-stage and two-stage techniques were compared for maturation rates. Patients with successful and failed maturation were compared for baseline characteristics and anatomic factors. Of 122 BBT-AVF procedures, 54 were created with the one-stage and 68 were created with the two-stage technique. The mean age of the patients was 58.2 ± 13.8, the mean brachial artery and basilic vein diameters were 3.91 ± 1.02 mm, and 3.39 ± 1.16 mm. Of 122 included patients, 88 (72.1%) had mature AVFs at follow-up. The AVF maturation rates were similar between the one- and two-stage groups (70.4% vs 73.5%; P = .699). Lower age (62.8 ± 12.5 vs 56.5 ± 13.9; P = .023) and greater brachial artery diameter (3.09 ± 0.84 mm vs 4.23 ± 1.76 mm; P < .048) were the only factors affecting the AVF maturation in univariate analysis. Gender, extremity side, diabetes mellitus, hypertension, and targeted vein diameter were not found to affect the AVF maturation (P = .301, P = .084, P = .134, P = .858, P = .127). Target artery diameter (P = .049) was the only significant factor affecting BBT-AVF maturation in multivariate analysis. One-stage and two-stage BBT-AVFs are similar in terms of maturation rates. Targeted artery diameter was the only factor important in BBT-AVF maturation in our study group. The two-stage technique can be preferred considering smaller incision size and lower complication rate in patients with suitable anatomy.

Primary Failure of Autogenous Arteriovenous Fistula: Critical Analysis

Introduction:

Permanent vascular access is an essential intervention in patients with advanced chronic kidney disease (CKD) and its success depends on various non-modifiable and modifiable factors. Considering the element of unpredictability and failure, we attempted to analyze various factors responsible for primary arteriovenous fistula (AVF) failure in presumed high-risk groups.

Materials and Methods:

We conducted an observational study of newly created AVFs at a tertiary referral government hospital in Eastern India between January 2014 and June 2015. All adult CKD patients undergoing AVF creation were included. Primary AVF failure was assessed at 12 weeks and total follow-up was 24 weeks in presumed high-risk groups of females, patients aged ≥65 years and those with diabetes mellitus.

Results:

Female gender was at a higher risk of primary AVF failure if aged ≥65 years (P = 0.0026), second AVF creation (P = 0.03), loupe magnification not used (P = 0.03), arterial plaque (P = 0.028), absent immediate thrill, and with radiocephalic AVF (P = 0.02). Absent immediate thrill (<0.0001) and AVF size ≤5 mm (P = 0.002) were important independent risk factors for primary failure. Diabetes or elderly age did not have additional risk, except with uncontrolled hypertension and female gender.

Conclusion:

Female gender was at a higher risk of poor unassisted AVF patency if their age was ≥65 years, had second AVF creation, loupe magnification not used or if arterial plaque was present. An absence of thrill immediately or at 24 hours or an AVF diameter ≤5 mm were independent intraoperative factors for poor outcome. On the contrary, diabetics, elderly males and intimal thickness were essentially noncontributors for AVF failure, except in few subsets.

Elderly patients, isometric exercise, and native vascular access maturation: An unsolved question?

INTRODUCTION

The number of elderly patients undergoing hemodialysis is steadily increasing. The choice and management of vascular access (VA) in these patients are difficult, and the role of postoperative isometric exercises on native VA maturation in the elderly population is not clearly established.

OBJECTIVES

To assess the effect of postoperative isometric exercises on native VA maturation in patients older than 75 years with advanced chronic kidney disease.

METHODOLOGY

This was a randomized single-center study over a 24-month period. Postoperative isometric exercises were performed in the exercise group (EG), while the control group (CG) received usual care. Demographic data, muscle strength (using handgrip [HG] dynamometer), Doppler ultrasound (DUS), incidence of VA complications, and clinical and DUS maturation were assessed at 4 and 8 weeks.

RESULTS

A total of 27 patients were included (EG: 14, CG: 13). The mean age of the patients was 79.9 ± 2.8 years; 74.1% were men, and 59.2% had radiocephalic VA. Demographic data, HG, and DUS measurements were similar at baseline. DUS measurements significantly increased in both groups at the end of the study. A significant increase in HG (19.1 ± 7.8 kg vs. 22.9 ± 9.7 kg, P = 0.001) and the highest clinical (CG vs. EG: 46.2% vs. 78.6%; P = 0.049) and DUS maturation (CG vs. EG: 30.8% vs. 71.4%; P = 0.041) were observed in the EG at 8 weeks. Globally, medical or surgical VA complications were lower in the EG and mainly included significant stenosis (CG vs. EG: 23.1% vs. 7.1%), although no significant differences were observed.

CONCLUSIONS

Once a native VA is indicated in elderly patients, postoperative isometric exercise should be considered in order to improve the odds of achieving a mature functional arteriovenous fistula. Further studies are required to support our findings in this population.

Different risk factors are associated with vascular access patency after construction and percutaneous transluminal angioplasty in patients starting hemodialysis

BACKGROUND

The objective of this multicenter, prospective observational study was to determine the factors related to patency rates after construction of vascular access (VA) and the first percutaneous transluminal angioplasty (PTA).

METHODS

The 24-month primary and secondary patency rates after construction of a radiocephalic arteriovenous fistula (RC-AVF) and arteriovenous graft (AVG) were evaluated using the Kaplan-Meier method and log-rank test. The 12-month post-PTA patency rate was also investigated. A Cox proportional hazard model was used to identify clinical parameters associated with the primary patency rate and the post-PTA patency rate.

RESULTS

A total of 611 patients were enrolled in the study. The primary patency rate after VA construction was lower in hemodialysis (HD) patients with an AVG than in those with an AVF. Aging (hazard ratio [HR], 1.02 per 1 year; p < 0.001), female sex (HR, 1.41; p = 0.03), diabetes mellitus (HR, 1.37; p = 0.03), low serum albumin (HR, 0.76 per 1-g/dL decrease; p = 0.02), and use of an erythropoietin-stimulating agent (HR, 1.62; p = 0.02) were risk factors for VA problems. The post-PTA patency rate was associated with aging (HR, 1.02; p < 0.001), diabetes mellitus (HR, 1.49; p = 0.02), polycystic kidney disease (HR, 2.14; p = 0.01), temporary catheter use for initiation of HD (HR, 1.60; p = 0.02), and period from VA construction to use (HR, 0.99; p = 0.04).

CONCLUSION

Although a poor patency rate is commonly associated with advanced age and diabetes, different risk factors affect patency between VA construction and the first PTA.