2005 Annual Report: ESRD Clinical Performance Measures Project

Association of albumin to non-high-density lipoprotein cholesterol ratio with mortality in peritoneal dialysis patients

OBJECTIVE

Malnutrition and inflammation are associated with mortality in peritoneal dialysis (PD) patients. Serum albumin and non-high-density lipoprotein cholesterol (non-HDL-C) are independently associated with mortality in PD patients. Combining albumin and non-HDL-C with mortality may be more plausible in clinical practice.

METHODS

This retrospective cohort study included 1954 Chinese PD patients from 1 January 2009 to 31 December 2016. Kaplan-Meier curve was used to determine the relationship between albumin to non-HDL-C ratio and all-cause mortality. Cox regression analysis was applied to assess the independent predictive value while adjusting for confounding factors. Competitive risk analysis was used to examine the effects of other outcomes on all-cause mortality prognosis.

RESULTS

In the 33-month follow-up period, there were 538 all-cause deaths. Kaplan-Meier analysis presented significant differences in all-cause mortality. Multivariate Cox regression showed that the risk of all-cause mortality was lower in the moderate group (9.36-12.79) (HR, 0.731; 95% CI, 0.593-0.902, p = 0.004) and the highest group (>12.79) (HR, 0.705; 95% CI, 0.565-0.879, p = 0.002) compared to the lowest group (≤9.36). Competitive risk analysis revealed significant differences for all-cause mortality (p < 0.001), while there was no statistical significance for other competing events.

CONCLUSIONS

Low albumin to non-HDL-C ratio was associated with a high risk of all-cause mortality in PD patients. It may serve as a potential prognostic biomarker in PD patients.

Global variability of vascular and peritoneal access for chronic dialysis

AIM

Vascular and peritoneal access are essential elements for sustainability of chronic dialysis programs. Data on availability, patterns of use, funding models, and workforce for vascular and peritoneal accesses for dialysis at a global scale is limited.

METHODS

An electronic survey of national leaders of nephrology societies, consumer representative organizations, and policymakers was conducted from July to September 2018. Questions focused on types of accesses used to initiate dialysis, funding for services, and availability of providers for access creation.

RESULTS

Data from 167 countries were available. In 31 countries (25% of surveyed countries), >75% of patients initiated haemodialysis (HD) with a temporary catheter. Seven countries (5% of surveyed countries) had >75% of patients initiating HD with arteriovenous fistulas or grafts. Seven countries (5% of surveyed countries) had >75% of their patients starting HD with tunnelled dialysis catheters. 57% of low-income countries (LICs) had >75% of their patients initiating HD with a temporary catheter compared to 5% of high-income countries (HICs). Shortages of surgeons to create vascular access were reported in 91% of LIC compared to 46% in HIC. Approximately 95% of participating countries in the LIC category reported shortages of surgeons for peritoneal dialysis (PD) access compared to 26% in HIC. Public funding was available for central venous catheters, fistula/graft creation, and PD catheter surgery in 57%, 54% and 54% of countries, respectively.

CONCLUSION

There is a substantial variation in the availability, funding, workforce, and utilization of vascular and peritoneal access for dialysis across countries regions, with major gaps in low-income countries.

Personalising haemodialysis treatment with incremental dialysis for incident patients with end-stage kidney disease: an implementation study protocol

INTRODUCTION

Incremental dialysis is a personalised dialysis prescription based on residual kidney function that allows for the initial use of shorter duration, less frequent and less intense dialysis. It has been associated with enhanced quality of life and decreased healthcare costs when compared with conventional dialysis. While nephrologists report prescribing incremental dialysis, few dialysis programmes offer a systematic approach in offering and evaluating its use. To move evidence into practice, and in order to improve the safety and quality of providing incremental dialysis care, we have designed an implementation study. This study aims to evaluate the systematic assessment of patients starting facility-based haemodialysis for eligibility for incremental dialysis, and the prescription and monitoring of incremental dialysis treatment.

METHODS AND ANALYSIS

A hybrid effectiveness and implementation study design is being used to evaluate the implementation of the programme at dialysis sites in Alberta, Canada. The Reach, Effectiveness, Adoption, Implementation and Maintenance framework will be used to capture individual-level and organisational-level impact of the project. Clinical outcomes related to kidney function will be monitored on an ongoing basis, and patient-reported outcomes and experience measures will be collected at baseline and then quarterly throughout the first year of dialysis.

ETHICS AND DISSEMINATION

The study was approved by the Health Research Ethics Board of the University of Alberta. The study is funded by the Strategic Clinical Networks of Alberta Health Services. The study will help answer important questions on the effectiveness of incremental dialysis, and inform the acceptability, adoption, feasibility, reach and sustainability of incremental dialysis within provision of haemodialysis care.

Chinese Clinical Practice Guideline for the Management of "CKD-PeriDialysis"-the Periods Prior to and in the Early-Stage of Initial Dialysis

The National Experts Group on Nephrology have developed these guidelines to improve the management of pre-dialysis and initial dialysis patients with chronic kidney disease (CKD) (two periods contiguous with dialysis initiation termed here 'PeriDialysis CKD'). The pre-dialysis period is variable, whereas the initial dialysis period is more fixed at 3 months to 6 months after initiating dialysis. The new concept and characteristics of 'CKD-PeriDialysis' are proposed in the guideline. During the CKD-PeriDialysis period, the incidence rate of complications, mortality and treatment cost significantly increases and the glomerular filtration rate (GFR) rapidly decreases, which requires intensive management. The guideline systematically and comprehensively elaborates the recommendations for indicators to be used in for disease evaluation, timing and mode selection of renal replacement therapy, dialysis adequacy evaluation, and diagnosis and treatment of common PeriDialysis complications. Finally, future research directions of CKD-PeriDialysis are proposed. CKD-PeriDialysis management is a difficult clinical issue in kidney disease, and the development and implementation of these guidelines is important to improve the management of CKD-PeriDialysis patients in China, which could ultimately improve survival rates and quality of life, and reduce the medical burden.

Low-Density Lipoprotein Cholesterol and Mortality in Peritoneal Dialysis

Background

In dialysis patients, lowering low-density lipoprotein cholesterol (LDL-C) did not provide benefits, which seemed implausible in clinical practice. We hypothesized a U-shaped association between LDL-C and mortality in dialysis patients.

Methods

In this multi-center retrospective real-world cohort study, 3,565 incident Chinese peritoneal dialysis (PD) patients between January 1, 2005, and May 31, 2020, were included. The associations between baseline LDL-C and mortality were examined using cause-specific hazard models.

Results

Of 3,565 patients, 820 died, including 415 cardiovascular deaths. As compared with the reference range (2.26-2.60 mmol/L), both higher levels of LDL-C (&gt; 2.60 mmol/L) and lower levels of LDL-C (&lt; 2.26 mmol/L) were associated with increased risks of all-cause mortality (hazard ratio [HR],1.35, 95% confidence index [CI], 1.09-1.66; HR 1.36, 95%CI, 1.13-1.64) and cardiovascular mortality (HR, 1.31, 95% CI, 1.10-1.72; HR, 1.64; 95% CI, 1.22-2.19). Malnutrition (albumin &lt; 36.0 g/L) modified the association between LDL-C and cardiovascular mortality (P for interaction = 0.01). A significantly increased risk of cardiovascular mortality was observed among patients with malnutrition and lower levels of LDL-C (HR 2.96, 95%CI 1.43-6.12) or higher levels of LDL-C (HR 2.81, 95%CI 1.38-5.72).

Conclusion

Low and high levels of LDL-C at the start of PD procedure were associated with increased all-cause and cardiovascular mortality risks. Malnutrition may modify the association of LDL-C with cardiovascular mortality.

Albumin to Total Cholesterol Ratio and Mortality in Peritoneal Dialysis

Background

Serum albumin and total cholesterol are associated with mortality. In clinical practice, evaluating the association of combining album and total cholesterol with mortality may be more reasonable. Thus, we examined the association between serum albumin to total cholesterol ratio and mortality in peritoneal dialysis (PD) patients.

Methods

We conducted a retrospective cohort study of 3447 incident continuous ambulatory peritoneal dialysis (CAPD) patients from five PD centers in China from 1 January 2005 and 31 May 2020. The association between albumin to total cholesterol ratio and mortality was evaluated.

Results

With a median follow-up of 39.3 months, 762 (22.1%) all-cause deaths occurred, including 382 (11.1%) cardiovascular deaths. As compared with a serum albumin to total cholesterol ratio of 0.77–0.82 (reference range), a higher ratio (>0.82) was associated with increased risks of all-cause mortality[hazards ratio (HR), 1.54; 95% confidence interval (CI), 1.16–2.05, E-value = 2.45] and cardiovascular mortality (HR, 2.10; 95% CI, 1.35–3.29, E-value = 3.62). A lower ratio (<0.77) was also associated with increased risks of all-cause mortality (HR, 1.46; 95% CI, 1.10–1.94, E-value = 2.28) and cardiovascular mortality (HR, 1.78; 95% CI, 1.14–2.78, E-value = 2.96) compared with the reference. No interaction was observed in subgroup analyses of age, sex, diabetes mellitus, hypertension, prior cardiovascular disease, and hyperlipidemia, and malnutrition (serum albumin <3.6 g/dL).

Conclusion

An albumin to total cholesterol ratio before the start of PD between 0.77 and 0.82 was associated with a lower risk of death than a higher or lower ratio, resulting in a U-curve association. Therefore, serum albumin to total cholesterol ratio, as an inexpensive and readily available biochemical biomarker, may further improve the stratification risk of mortality in PD patients.

Determining factors of functioning in hemodialysis patients using the international classification of functioning, disability and health

Background

Hemodialysis (HD) treatment affects functioning, physical activity level, clinical biomarkers, and body composition. However, the association between these variables with functioning, considering International Classification of Functioning, Disability and Health (ICF) domains remains unclear. Thus, the aim of this study was to investigate the possible association between physical activity, biomarkers, and body composition with functioning in HD patients in reference to the ICF.

Methods

Eighty HD patients performed different tests grouped according to ICF domain: Body structure and function – handgrip strength (HS), 5-repetition sit-to-stand test, and 60-s sit-to-stand test (5-STS, 60-STS, respectively); Activity – short physical performance battery (SPPB); and Participation – participation scale questionnaire. Physical activity [Human Activity Profile questionnaire (HAP)], body composition (Dual-energy X-ray absorptiometry), Parathormone (PTH), and alkaline phosphatase were analyzed as possible variables associated with ICF domains. Data analyses were performed using simple and multiple regression models adjusted for age, duration of HD, and diuresis volume.

Results

In the body structure and function domain, appendicular lean mass, PTH level, and age were associated with HS (R² = 0.558); HAP and PTH were associated with 5-STS (R² = 0.263); and HAP, PTH, duration of HD, and age were associated with 60-STS (R² = 0.337). In the activity domain, HAP, PTH, alkaline phosphatase, duration of HD, age, and body fat were associated with SPPB (R² = 0.689). Finally, only HAP was associated with the participation scale (R² = 0.067).

Conclusion

Physical activity and PTH levels are determinant protagonists of functioning in all ICF domains in hemodialysis patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02719-5.

Shared decision-making in hemodialysis vascular access practice

Shared decision-making (SDM) is a process of collaborative deliberation in the dyadic patient-physician interaction whereby physicians inform the patients about the pros and cons of all available treatment options and reach an agreement with the patients on their preferred treatment plan. In hemodialysis vascular access practice, SDM advocates a deliberative approach based on the existence of reasonable alternatives-that is, arteriovenous fistula, arteriovenous graft, and central venous catheter-so that patients are able to form and share preferences about access options. In spite of its ethical imperative, SDM is not broadly applied in hemodialysis vascular access planning. Physicians and surgeons commonly deliver prescriptive fistula-centered recommendations concerning the approach to vascular access care. This paternalistic approach has been shaped by directions from long-held clinical practice guidelines and is reinforced by financial payment models linked with the prevalence of arteriovenous fistula in patients on hemodialysis. Awareness is growing that what may have initially seemed a medically and surgically appropriate approach might not always be focused on each individual's goals of care. Clinician's recommendations for vascular access often do not sufficiently consider the uncertainty surrounding the potential benefits of the decision or the cumulative impact of the decision on patient's quality of life. In the evolving health care landscape, it is time for the practice of hemodialysis vascular access to shift from a hierarchical doctor-patient approach to patient-centered care. In this article we review the current state of vascular access practice, present arguments why SDM is necessary in vascular access planning, review barriers and potential solutions to SDM implementation, and discuss future research contingent on an effective system of physician-patient participative decision-making in hemodialysis vascular access practice.

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

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

Ultrasound guided interventional procedures on arteriovenous fistulae

Autogenous (AVF) and prosthetic (AVG) arteriovenous fistulas are the vascular accesses (VA) of choice for hemodialysis thanks to their improved patency, reduced costs, and lower rate of infections relative to catheters.

In an effort to maximize the number of primary AVF and AVG, shorten maturation times for AVF, and reduce the number of indwelling catheters, several new techniques have been developed within the context of an overall program designed to optimize access care.

This approach includes: (a) Primary Intraoperative Balloon Angioplasty on the vessels selected for AV creation whether small-sized or altered by pre-existing lesions; (b) Percutaneous Transluminal Angioplasty (PTA) on AVF and AVG stenosis, performed under ultrasonographic (UG) or fluoroscopic guide (FG).

We report the experience of two Center in performing the above mentioned procedures on even complex VA. The wise adoption of these techniques may avail to meet the stringent demands for reliable VA placement as defined by KDOQI and, thereby, expand the duration and quality of life for hemodialysis patients.

A five-year longitudinal study of the relation between end-stage kidney disease as the outcomes

Background

Patients with end-stage kidney disease (ESKD) are required to undergo consecutive time-based blood and biochemical tests to determine the progression of the disease according to changes in their blood and biochemical data. This study employed a random intercept model to investigate whether time-based blood and biochemical data present any notable clinical meaning that can be used to track disease progression.

Methods

This study conducted a retrospective analysis on the dialytic data of 148 patients with ESKD, who received hemodialysis between January 2005 and December 2015. The patients were all at least 20 years old, and the data used included patient demographic information and results for at least 60 blood and biochemical tests. A random intercept model was used to analyze the relationships among blood and biochemical test results, explanatory variables of patient comorbidities, and time.

Results

The age range of patients was between 33 and 98 years, with an average of 66.1 years and those over 65 years old comprising 51.3% (n = 76) of the total. Furthermore, hypertension was found to be the most common comorbidity among patients (87.2%, n = 129), followed by anemia (48.6%, n = 72), diabetes (47.3%, n = 70), dyslipidemia (19.6%, n = 29), and peptic ulcer (19.6%, n = 29). Coronary atherosclerotic heart disease is a comorbidity that can serve as a strong and independent marker for prognosis in patients with ESKD. Serum creatinine level can serve as an alternative indicator because patients with ESKD and comorbid diabetes may exhibit increased creatinine levels.

Conclusions

The results of a parameter estimation for longitudinal data analysis suggested that comorbidity and time were critical variables influencing blood and biochemical test results. Furthermore, WBC and HBC, HCT, albumin, protein, and creatinine levels were recognized as variables of critical significance. The results obtained in this study indicate that multimorbidity increases the treatment burden on patients, leading to polypharmacy. For this reason, comprehensive care and treatment of ESKD cannot rely solely on data from one single time point; instead, longitudinal analysis and other data that can affect patient prognosis must also be considered.

Nitinol stent-assisted maturation of the dysfunctional cannulation zone in the immature arteriovenous fistula

INTRODUCTION

The native arteriovenous fistula may remain immature despite adequate arterial inflow after formation. This may occur when the puncturable vein segment (cannulation zone) is too small to be reliably punctured, occluded or too deep under the skin for needle access. We performed stenting (stent-assisted maturation) of arteriovenous fistulas with an immature cannulation zone, allowing for a large subcutaneous channel which could then be immediately punctured for dialysis.

METHODS

We performed a retrospective review of 49 patients (mean age was 58.7 ± 16.09 (12-83) years, mean arteriovenous fistula age of 162.6 ± 27.28 days) with end-stage renal failure who underwent balloon dilatation and bare-metal stent implantation (1.6 ± 0.67 (1-3) stents, median diameter and length of 8 (5-14) mm and 80 (40-150) mm, respectively) through their cannulation zone (forced maturation). Radiocephalic (35 arteriovenous fistulas), brachiocephalic (10 arteriovenous fistulas) and autogenous loop arteriovenous fistulas (4 arteriovenous fistulas) were included with 30 patients (61.2%) having an inadequate cannulation zone venous diameter, 9 patients (18.4%) having an absent cannulation zone and 10 patients (20.4%) having a patent cannulation zone deeper than 1 cm which was not reliably puncturable. The study was conducted over 9 years (January 2008-December 2016) with implantation of the SMART^® stent and Absolute Pro^® stent in 61.2% and 38.8%, respectively. Long-term outcomes including primary useable segmental and access circuit patency as well as assisted primary access circuit patency, rate of re-intervention, technical success and complications were analysed.

RESULTS

At 6 months, 12 months and 4 years, respectively, cannulation zone primary patency was 84.4%, 74.4% and 56.1% and access circuit primary patency was 62.2%, 45.3% and 23.2%; however, assisted primary access circuit patency was 95.6%, 91.1% and 83.8%, achieved with an endovascular re-intervention rate of 0.53 procedures/year with only four thrombosed circuits occurring.

DISCUSSION

Forced maturation using nitinol stents allows for long-term haemodialysis access with a low rate of re-intervention.

Characteristics of non-mature but functional autogenous radiocephalic fistulas in hemodialysis patients: A prospective cohort study

TARGET

To compare the ultrasound characteristics between functional, mature arteriovenous fistulas and functional, non-mature arteriovenous fistulas and to identify the predictors of arteriovenous fistula maturation in the forearm.

METHODS

Patients with newly set-up functional arteriovenous fistulas were enrolled in this prospective cohort study. Ultrasound examinations were conducted pre-operatively and post-operatively. The inner vessel diameter, blood flow volume, and resistance index were measured and compared between the maturation group (Group M) and non-maturation group (Group N). Baseline parameters were calculated to determine the predictors of non-maturation of arteriovenous fistulas.

RESULTS

All 52 patients with functional arteriovenous fistulas, who were categorized into Group M (25 patients, 48.08%) and Group N (27 patients, 51.92%), finished 24 weeks of follow-up after arteriovenous fistula surgery. The arteriovenous fistulas displayed a significant and rapid increase in the vessel diameter (mean increase of 1.34 times in the arteries and 1.92 times in the veins) and blood flow volume (mean increase of 9.29 times of the arteries and 43.66 times of the veins) and a decrease in the resistance index (mean decrease in 48.00% in the arteries) 8 weeks after surgery. Group N had a lesser increase in the vessel diameters (1.78 times vs 2.06 times, t = -3.136, p = 0.003) and blood flow volume (33.98 times vs 54.11 times, t = -2.383, p = 0.021) of the cephalic vein draining segments (a6) than Group M. The baseline diameter of a6 was the only independent predictor (regression coefficient = 26.229, p = 0.008) of maturation of the functional arteriovenous fistulas after correcting for sex, age, diabetes kidney disease, weight, and height.

CONCLUSION

The baseline diameter of the cephalic vein was the only predictor of arteriovenous fistula maturation based on the pre-operative ultrasound measurements in Chinese hemodialysis patients.

Acute Kidney Injury in the Outpatient Setting Associates with Risk of End-Stage Renal Disease and Death in Patients with CKD

Current acute kidney injury (AKI) diagnostic criteria are restricted to the inpatient setting. We proposed a new AKI diagnostic algorithm for the outpatient setting and evaluate whether outpatient AKI (AKIOPT) modifies the disease course among patients with chronic kidney disease (CKD) enrolled in the national predialysis registry. AKIOPT was detected when a 50% increase in serum creatinine level or 35% decline in eGFR was observed in the 180-day period prior to enrollment in the predialysis care program. Outcomes were progression to end-stage renal disease (ESRD) and all-cause mortality. Association analyses were performed using multiple Cox regression and coarsened exact matching (CEM) analysis. Among 6,046 patients, 31.5% (1,905 patients) had developed AKIOPT within the 180-day period before enrollment. The adjusted hazard ratios of the 1-year and overall risk of ESRD among patients with preceding AKIOPT compared with those without AKIOPT were 2.61 (95% CI: 2.15-3.18) and 1.97 (1.72-2.26), respectively. For 1-year and overall risk of all-cause mortality, patients with AKIOPT had respectively a 141% (95% CI: 89-209%) and 84% (56-117%) higher risk than those without AKIOPT. This statistical inference remained robust in CEM analysis. We also discovered a complete reversal in the eGFR slope before and after the AKIOPT from -10.61 ± 0.32 to 0.25 ± 0.30 mL/min/1.73 m2 per year; however, the loss of kidney function is not recovered. The new AKIOPT diagnostic algorithm provides prognostic insight in patients with CKD.

Port-a-Cath device: A solution for peritoneal dialysis patients with exhausted access

With aging population and chronic kidney disease burden increasing worldwide, the need for renal replacement therapy is rising and our patients are getting more complex due to comorbidities and long-standing kidney disease. Deteriorated vascular capital is a frequent feature we have to deal with these days, making even obtaining routine blood tests a hard task. We present two case reports of peritoneal dialysis patients without a peripheral vein access were a Port-a-Cath (Port-a-Cath^® Deltec^® Smiths Medical) was placed to sort out long-term access. Port-a-Cath manipulation was simple, safe and had no complications neither at implantation nor during its use. We believe that Port-a-Cath placement is an option to be considered when coping with end-stage venous access.

Dynamic variation of the axillary veins due to intrathoracic pressure changes: A prospective sonographic study

INTRODUCTION

The ultrasound-guided axillary vein is becoming a compulsory alternative vessel for central venous catheterization and the anatomical position offers several potential advantages over blind, subclavian vein techniques.

OBJECTIVE

To determine the degree of dynamic variation of the axillary vein size measured by ultrasound prior to the induction of general anesthesia and after starting controlled mechanical ventilation.

DESIGN

Prospective, observational study.

METHODS

One hundred ten patients undergoing elective surgery were enrolled and classified according to sex, age, and body mass index. Two-dimensional cross-sectional vein diameter, area, and mean flow velocity were performed using ultrasound on both the left and right axillary veins of each subject before and after induction of anesthesia.

RESULTS

There was statistically significant evidence showing that the axillary vein area increases when patients are mechanically ventilated. When considering venous flow velocity as a primary outcome, velocity decreased after patients moved from spontaneous to mechanical ventilation (coefficient = -0.267), but this relationship failed to achieve statistical significance (t = -1.355, p = 0.179).

CONCLUSIONS

Anatomical variations in depth and diameter as well as the collapsibility due to intrathoracic pressures changes represent common challenges that face clinicians during central venous catheterization of the axillary vein. A noteworthy increase in vessel size as patients transition from spontaneous to mechanical ventilation may theoretically improve first-pass cannulation success with practitioners skilled in both ultrasound and procedure. As a result, placing a centrally inserted central catheter after the induction of anesthesia may be beneficial.

Variables associated with successful vascular access cannulation in hemodialysis patients: a prospective cohort study

BACKGROUND

Successful vascular access (VA) cannulation is integral to the delivery of adequate dialysis, highlighting the importance of ensuring the viability of arteriovenous access in hemodialysis (HD) patients. Missed VA cannulation can lead to infection, infiltration, hematoma or aneurysm formation resulting in the need for access revision, central venous catheter (CVC) placement, or permanent loss of VA. Cannulation-related complications can also negatively impact on a patient's dialysis experience and quality of life. This study aimed to identify patient, VA and nurse factors associated with unsuccessful VA cannulations.

METHODS

A prospective cohort study was conducted in HD patients with a permanent VA from three HD units. Data on patient, VA and nurse characteristics, plus, cannulation technique were collected for each episode of cannulation. General Estimating Equation was used to fit a repeated measures logistic regression to determine the odds of cannulation success.

RESULTS

We collected data on 1946 episodes of cannulation (83.9% fistula) in 149 patients by 63 nurses. Cannulation included use of tourniquet (62.9%), ultrasound (4.1%) and was by rope ladder (73.8%) or area (24.7%) technique. The miscannulation rate was 4.4% (n = 85) with a third of patients (n = 47) having at least one episode of miscannulation. Extravasation (n = 17, 0.9%) and use of an existing CVC (n = 6, 0.6%) were rare. Multivariable characteristics of successful cannulation included fistula compared with graft [OR 4.38; 95%CI, 1.89-10.1]; older access [OR 1.68; 95%CI, 1.32-2.14]; absence of stent [OR 3.37; 95%CI, 1.39-8.19]; no ultrasound [OR 13.7; 95%CI, 6.52-28.6]; no tourniquet [OR 2.32; 95%CI, 1.15-4.66]; and lack of post graduate certificate in renal nursing [OR 2.27; 95%CI, 1.31-3.93].

CONCLUSION

This study demonstrated a low rate of miscannulation. Further research is required on ultrasound-guided cannulation. Identifying variables associated with successful cannulation may be used to develop a VA cannulation complexity instrument that could be utilised to match to the cannulation skill of a competency-assessed nurse, thereby minimising the risk of missed cannulation and trauma.

Quality assessment of vascular access procedures for hemodialysis: A position paper of the Vascular Access Society based on the analysis of existing guidelines

Quality assessment in vascular access procedures for hemodialysis is not clearly defined. The aim of this article is to compare various guidelines regarding recommendation on quality control in angioaccess surgery. The overall population of end-stage renal disease patients and patients in need for hemodialysis treatment is growing every year. Chronic intermittent hemodialysis is still the main therapy. The formation of a functional angioaccess is the cornerstone in the management of those patients. Native (autologous) arteriovenous fistula is the best vascular access available. A relatively high percentage of primary failure and fistula abandonment increases the need for quality control in this field of surgery. There are very few recommendations of quality assessment on creation of a vascular access for hemodialysis in the searched guidelines. Some guidelines recommend the proportion of native arteriovenous fistula in incident and prevalent patients as well as the maximum tolerable percentage of central venous catheters and complications. According to some guidelines, surgeon’s experience and expertise have a considerable influence on outcomes. There are no specific recommendations regarding surgeon’s specialty, grade, level of skills, and experience. In conclusion, there is a weak recommendation in the guidelines on quality control in vascular access surgery. Quality assessment criteria should be defined in this field of surgery. According to these criteria, patients and nephrologists could choose the best vascular access center or surgeon. Centers with best results should be referral centers, and centers with poorer results should implement quality improvement programs.

Renal Perfusion during Hemodialysis: Intradialytic Blood Flow Decline and Effects of Dialysate Cooling

BACKGROUND

Residual renal function (RRF) confers survival in patients with ESRD but declines after initiating hemodialysis. Previous research shows that dialysate cooling reduces hemodialysis-induced circulatory stress and protects the brain and heart from ischemic injury. Whether hemodialysis-induced circulatory stress affects renal perfusion, and if it can be ameliorated with dialysate cooling to potentially reduce RRF loss, is unknown.

METHODS

We used renal computed tomography perfusion imaging to scan 29 patients undergoing continuous dialysis under standard (36.5°C dialysate temperature) conditions; we also scanned another 15 patients under both standard and cooled (35.0°C) conditions. Imaging was performed immediately before, 3 hours into, and 15 minutes after hemodialysis sessions. We used perfusion maps to quantify renal perfusion. To provide a reference to another organ vulnerable to hemodialysis-induced ischemic injury, we also used echocardiography to assess intradialytic myocardial stunning.

RESULTS

During standard hemodialysis, renal perfusion decreased 18.4% (P<0.005) and correlated with myocardial injury (r=-0.33; P<0.05). During sessions with dialysis cooling, patients experienced a 10.6% decrease in perfusion (not significantly different from the decline with standard hemodialysis), and ten of the 15 patients showed improved or no effect on myocardial stunning.

CONCLUSIONS

This study shows an acute decrease in renal perfusion during hemodialysis, a first step toward pathophysiologic characterization of hemodialysis-mediated RRF decline. Dialysate cooling ameliorated this decline but this effect did not reach statistical significance. Further study is needed to explore the potential of dialysate cooling as a therapeutic approach to slow RRF decline.

A systematic follow-up protocol achieving a low hemodialysis graft thrombosis rate

INTRODUCTION

Graft is an alternative to native arteriovenous fistula to ensure permanent vascular access in hemodialysis patients. The most common complication is significant stenosis, which frequently causes thrombosis and graft loss. Periodic monitoring and surveillance with elective correction of stenotic lesions can prolong graft survival.

OBJECTIVE

To describe the effect of early diagnosis of significant stenosis on the rate of thrombosis and graft patency.

METHODS

Retrospective, observational study of a cohort of 86 prevalent patients undergoing hemodialysis with a graft as their vascular access. We applied a systematic follow-up protocol of 115 grafts based on various screening methods of monitoring (clinical monitoring, pre-pump arterial pressure, dynamic venous pressure, percentage of recirculation, and dose of dialysis) in conjunction with surveillance (normalized intra-access venous pressure and access flow). The annual rates of thrombosis, and primary, primary-assisted, and secondary patency were assessed.

RESULTS

The incidence of significant stenosis and thrombosis was 57.4% (65/115) and 39.0% (45/115), respectively. Of all screening procedures, normalized intra-access venous pressure was the best predictor of significant stenosis (hazards ratio, 7.71; 95% confidence interval, 3.06-19.46). The annual rate of thrombosis fluctuated from 0 to 0.26 thromboses/patient/year, with an average rate of 0.14 thromboses/patient/year. Primary, primary-assisted, and secondary patency were 74%/79%/82%, 50%/60%/66%, and 23%/35%/37% at 1, 2, and 5 years, respectively.

CONCLUSION

The implementation of a systematic graft follow-up protocol combined with monitoring and surveillance enabled early diagnosis and elective correction of significant stenosis, prolonged graft patency, and a low thrombosis rate.

Options for end stage vascular access: Translumbar catheter, arterial-arterial access or right atrial graft?

Background:

Running out of vascular access for dialysis is thankfully rare, but despite this, most units will have a number of patients with few options and in a precarious state. The increasing longevity of dialysis patients portends more patients will reach minimal access options. End stage vascular access is poorly defined but classification may enable assessment and comparison of treatment options. Three options for patients with end stage access are a central venous catheter through a translumbar or transhepatic route, arterial-arterial prosthetic loop or a right atrial graft.

Aims:

The aims of this study are to provide a structured review of evidence for these procedures to allow application and guide practice for patients with end stage vascular access.

Methods:

A standardised search of published literature was performed of relevant studies. In addition, the references cited in those papers were assessed for any further available articles. All study types were included and reviewed by two authors independently. Primary outcomes were patient survival and secondary patency rate at 3 and 12 months. Secondary outcomes were long-term patency rates, mean time to cannulation and complications such as access dysfunction, thrombosis and infection.

Summary:

Based on the available evidence, it would appear that arterial-arterial prosthetic loop is a definitive option for maintaining dialysis access in patients with no more arteriovenous access options. Translumbar and transhepatic dialysis catheters may offer short- and medium-term options and right atrial grafts may also be suitable as an option where arterial-arterial prosthetic loop is unsuitable.

Using CorMatrix for partial and complete (re)construction of arteriovenous fistulas in haemodialysis patients: (Re)construction of arteriovenous fistulas with CorMatrix

INTRODUCTION

CorMatrix is an acellular extracellular matrix that acts as a biological scaffold and remodels into site-specific tissue. We used it for the (re)construction of arteriovenous fistulas.

METHODS

In this prospective pilot case study, we used CorMatrix in six patients. We included patients who required vascular access reconstruction due to thrombosis of unsalvageable arteriovenous fistulas, patients with high-flow arteriovenous fistulas and patients with microvasculature in which autologous arteriovenous fistulas did not mature, requiring reconstruction with a graft. We sutured the CorMatrix plate into a tubular shape and then constructed arterial and venous anastomoses.

RESULTS

There were no periprocedural complications, CorMatrix-related infections, bleeding or limb swelling after the procedures. CorMatrix was first punctured after 8-10 weeks. In five patients, a percutaneous angioplasty due to CorMatrix stenosis was performed; in one patient, a stent was placed due to refractory stenosis. We observed eight thromboses during the observation period (four in one patient). Perianastomotic stenosis of CorMatrix and interdialytic hypotension were the causes of the thrombosis in five patients, cephalic arch stenosis in two patients and thromboembolism to the brachial artery and arteriovenous fistula in one patient. Thrombendarteriectomy was successful in 87.5% of patients, and one patient required arteriovenous fistula reconstruction. After a median observation period of 12.5 (range 4-23) months, all arteriovenous fistulas were patent, with a median brachial artery flow of 1450 (range 700-1700) mL/min.

CONCLUSION

Arteriovenous fistula (re)construction with CorMatrix seems to be feasible and safe, with a relatively high incidence of neointimal hyperplasia, predominantly at venous anastomoses, but additional clinical studies are needed.

Perceptions about the dialysis modality decision process among peritoneal dialysis and in-center hemodialysis patients

BACKGROUND

Patients reaching end-stage renal disease must make a difficult decision regarding renal replacement therapy (RRT) options. Because the choice between dialysis modalities should include patient preferences, it is critical that patients are engaged in the dialysis modality decision. As part of the Empowering Patients on Choices for RRT (EPOCH-RRT) study, we assessed dialysis patients' perceptions of their dialysis modality decision-making process and the impact of their chosen modality on their lives.

METHODS

A 39-question survey was developed in collaboration with a multi-stakeholder advisory panel to assess perceptions of patients on either peritoneal dialysis (PD) or in-center hemodialysis (HD). The survey was disseminated to participants in the large US cohorts of the Dialysis Outcomes and Practice Patterns Study (DOPPS) and the Peritoneal DOPPS (PDOPPS). Survey responses were compared between PD and in-center HD patients using descriptive statistics, adjusted logistic generalized estimating equation models, and linear mixed regression models.

RESULTS

Six hundred fourteen PD and 1346 in-center HD participants responded. Compared with in-center HD participants, PD participants more frequently reported that they were engaged in the decision-making process, were provided enough information, understood differences between dialysis modalities, and felt satisfied with their modality choice. PD participants also reported more frequently than in-center HD participants that partners or spouses (79% vs. 70%), physician assistants (80% vs. 66%), and nursing staff (78% vs. 60%) had at least some involvement in the dialysis modality decision. Over 35% of PD and in-center HD participants did not know another dialysis patient at the time of their modality decision and over 60% did not know the disadvantages of their modality type. Participants using either dialysis modality perceived a moderate to high impact of dialysis on their lives.

CONCLUSIONS

PD participants were more engaged in the modality decision process compared to in-center HD participants. For both modalities, there is room for improvement in patient education and other support for patients choosing a dialysis modality.

Precurved non-tunnelled catheters for haemodialysis are comparable in terms of infections and malfunction as compared to tunnelled catheters: A retrospective cohort study

Background:

The main limitations of central venous catheters for haemodialysis access are infections and catheter malfunction. Our objective was to assess whether precurved non-tunnelled central venous catheters are comparable to tunnelled central venous catheters in terms of infection and catheter malfunction and to assess whether precurved non-tunnelled catheters are superior to straight catheters.

Materials and methods:

In this retrospective, observational cohort study, adult patients in whom a central venous catheter for haemodialysis was inserted between 2012 and 2016 were included. The primary endpoint was a combined endpoint consisting of the first occurrence of either an infection or catheter malfunction. The secondary endpoint was a combined endpoint of the removal of the central venous catheter due to either an infection or a catheter malfunction. Using multivariable analysis, cause-specific hazard ratios for endpoints were calculated for tunnelled catheter versus precurved non-tunnelled catheter, tunnelled catheter versus non-tunnelled catheter, and precurved versus straight non-tunnelled catheter.

Results:

A total of 1603 patients were included. No difference in reaching the primary endpoint was seen between tunnelled catheters, compared to precurved non-tunnelled catheters (hazard ratio, 0.91; 95% confidence interval, 0.70–1.19, p = 0.48). Tunnelled catheters were removed less often, compared to precurved non-tunnelled catheters (hazard ratio, 0.65; 95% confidence interval, 0.46–0.93; p = 0.02). A trend for less infections and catheter malfunctions was seen in precurved jugular non-tunnelled catheters compared to straight non-tunnelled catheters (hazard ratio, 0.60; 95% confidence interval, 0.24–1.50; p = 0.28) and were removed less often (hazard ratio, 0.41; 95% confidence interval, 0.18–0.93; p = 0.03).

Conclusion:

Tunnelled central venous catheters and precurved non-tunnelled central venous catheters showed no difference in reaching the combined endpoint of catheter-related infections and catheter malfunction. Tunnelled catheters get removed less often because of infection/malfunction than precurved non-tunnelled catheters.

Improving precision in prediction: Using kidney failure risk equations as a potential adjunct to vascular access planning

The timing of referral for creation of vascular access in a patient with declining kidney function is difficult to predict. Current methods may result in patients undergoing unnecessary procedures and subsequent interventions on accesses that are never used. Multiple variables, including time for assessment, surgery and follow-up that considers the likelihood of access failure, and the estimated rate of kidney function decline, make vascular access planning challenging and difficult to balance. Better prediction tools that incorporate the risks of progressive decline in kidney function with the risk of access failure and the competing risk of death would facilitate decision-making in vascular access. The kidney failure risk equation is a validated, simple online tool that estimates the probability of the 2- and 5-year risk of reaching end-stage kidney disease. While the use of the kidney failure risk equation has not been validated as an adjunct to planning vascular access, it has potential and may facilitate more individualised care and more appropriate allocation of resources.

Evaluation of factors affecting time to achieve dry weight among hemodialysis patients using bioimpedance spectroscopy

BACKGROUND

Achieving and maintaining dry weight appears to be an effective strategy for controlling and maintaining normotension among hypertensive patients on hemodialysis (HD).

OBJECTIVE

The present study aimed to determine the time at which the majority of patients achieve postdialysis dry weight using bioimpedance spectroscopy (BIS).

METHODS

A total of 220 HD patients were prospectively assessed for fluid overload using the Fresenius body composition monitor (BCM). BCM readings were taken at 30 and 45 min postdialysis.

RESULTS

Among the 220 patients included in this study, 120 (54.5%) achieved a euvolemic state at 30 min, and 25 (11.4%) achieved it at 45 min according to the BCM. In the multivariate analysis, vascular access other than arteriovenous fistula (AVF) (OR = 0.286, p value = 0.049) and cardiovascular disease (OR = 0.384, p value = 0.026) had a statistically significant negative association and receiving HD at Hospital Universiti Sains Malaysia (HUSM) (OR = 2.705, p value = 0.008) had a statistically significant positive association with achieving a euvolemic state at 30 min.

CONCLUSION

This suggests that assessing the hydration status at 45 min postdialysis in all patients or in those with identified risk factors for not achieving a euvolemic state at 30 min will provide a relatively accurate assessment for most patients.

Thigh arteriovenous grafts. Quantitative comparison with alternative options: A meta-analysis

Thigh arteriovenous grafts are required in a number of patients with exhausted upper extremity veins and comprise 1%-5% of the total access procedures performed. Alternative autogenous lower extremity options are the rarely used sapheno-tibial arteriovenous fistulae, the saphenous vein transpositions, and the femoral vein transpositions. The latter have proven to be the most durable lower limb access procedures, with low infection rates and their primary patency rates ranged from 74% up to 87% at 2 years. Synthetic thigh grafts are suitable for patients who are not good candidates for any upper limb or any autogenous lower limb access and their secondary patency rates ranged from 54% up to 83% at 2 years. Thigh grafts often get infected and their average weighed infection rate in 920 such grafts included in eight large series was 22.9%. A literature search was performed to evaluate thigh grafts compared with alternative options using meta-analysis. Lower limb accesses were found superior compared to HeRO^® device regarding 1-year primary failure rate (odds ratio = 0.28, confidence interval = 0.09-0.88, p = 0.03) and additionally autogenous lower limb accesses were found superior compared to thigh grafts regarding the 1-year primary failure rate (odds ratio = 6.54, confidence interval = 2.29-18.72, p = 0.0005).

Dialysis arteriovenous access monitoring and surveillance according to the 2017 Spanish Guidelines

The Spanish Multidisciplinary Group on Vascular Access (GEMAV), which includes experts from the five scientific societies involved (nephrology (S.E.N.), vascular surgery (SEACV), interventional radiology (SERAM-SERVEI), infectious diseases (SEIMC), and nephrology nursing (SEDEN)), along with the methodological support of the Iberoamerican Cochrane Centre, has developed the Spanish Clinical Guidelines on Vascular Access for Hemodialysis. This article summarizes the main issues from the guideline's chapter entitled "Monitoring and surveillance of arteriovenous access." We will analyze the current evidence on conflicting topics such as the value of the flow-based screening methods for the arteriovenous access surveillance or the role of Doppler ultrasound as the imaging exploration to confirm suspected stenosis. In addition, the concept of significant stenosis and the criteria to perform the elective intervention for stenosis were reviewed. The adoption of these guidelines will hopefully translate into a reduced risk of thrombosis and increased patency rates for both arteriovenous fistulas and grafts.

Radiological Central Vein Treatment in Vascular Access

In the last decades, the percutaneous interventional approach for the treatment of central venous obstructions (CVO) has become increasingly popular as the treatment of first choice because of its minimal invasiveness and reported success rates. CVOs are caused by a diverse spectrum of diseases which can be broadly categorized into two principal eliciting genera, either benign or malignant obstructions. The large group of benign venous obstructions includes the increasing number of end-stage renal disease patients with vascular access related complications. Due to the invasiveness and complexity of thoracic surgery for benign CVOs, the less invasive percutaneous interventional therapy can generally be considered the preferred treatment option. Initially, the radiological intervention consisted of balloon angioplasty alone, subsequently additional stent placement was applied. This was advocated as either primary placement or secondary in cases of elastic recoil or residual stenosis after percutaneous transluminal angioplasty (PTA). The efficacy of angioplasty of CVO in patients with vascular accesses, either with or without stenting, has been addressed by various studies. Overall, reports indicate an initial technical and clinical success rate above 95% and satisfactory patency rates. However, systematic follow-up and frequent re-interventions are necessary to maintain vascular patency to achieve long-term success.

Arteriovenous Fistulae vs. Arteriovenous Grafts: A Retrospective Review of 1,700 Consecutive Vascular access Cases

Objective

Vascular access (VA) procedures are rapidly becoming the most prevalent surgery in the United States. It is estimated that there will be over 500,000 VA procedures done this year. Previously, surgeons in the US were attempting many more non-autogenous grafts than autogenous fistulae. In recent years, there has been a great push called “Fistula First” to promote arteriovenous fistulae (AVF) as the first line of treatment vs. non-autogenous grafts. The goal of this investigation is to determine if too many fistulae are now being performed without attention to specific patient profiles.

Methods

A retrospective review of 1700 consecutive cases was performed by one surgeon at one institution between 1997 and 2005. Patients were categorized by demographics, co-morbidities, previous access procedures, access location, and type of graft. Patency was calculated. Kaplan-Meier, Cox regression and the Log Rank Test were used to analyze data. Access endpoints and complications were also documented.

Results

The study reviewed 1700 procedures. The median age was 52 (60.2% male) with 58.7% fistulae and 41.3% grafts. Median patency time was 10 months, with no statistically significant difference between access types. There was no significant difference in length of patency when comparing upper arm (70.1%), lower arm (24.5%) and thigh (5.4%). Graft infection rate was 9.5% and fistula infection rate was 0.9% (p<0.001). The overall infection rate was 4.5%, and decreased patency significantly (4 vs. 11 months). Thrombosis occurred in 24.7% of grafts and 9.0% of fistulae. Thrombosed grafts had better salvage rates (8 vs. 4 months, p<0.001). The data showed diabetes, HTN and HIV have no overall impact on patency.

Conclusions

AVF and grafts are both useful in providing VA for patients requiring hemodialysis. Our data shows that grafts are equivalent in long-term patency. Therefore, it is apparent in those patients who are not candidates for an AV fistula; an AV graft for VA should be placed.

Patient-Centric Analysis of Dialysis Access Outcomes

Objective

Dialysis access literature has traditionally focused on fistula patency as the primary outcome measure, but this approach falls short in describing the entire spectrum of dialysis access care. Using our prospectively maintained vascular access data base, a comprehensive, patient-centered analysis of arteriovenous access placement and interventions, central venous catheter use, and associated complications is performed.

Methods

Twenty-six patients receiving 39 arteriovenous fistula (AVF), eight prosthetic grafts and 52 catheters were followed longitudinally for an average of 4.1 yrs to determine the time of initial cannulation, need for revision, and the time of abandonment for each AV access. Access complications secondary to infection, thrombosis, stenosis, and aneurysmal degeneration were tabulated. The time of permanent dialysis catheter placement and removal was collected, along with infection and thrombotic complications related to their use.

Results

Fifty-four percent of the AVFs matured without the need for intervention, while 13% required revision to promote maturation. One-third of the AVFs failed primarily or following revision and were never used for dialysis. Fistulae were initially cannulated an average of 9.5 months following implantation and lasted 27.2 months before abandonment. AVF revisions were performed an average of 7.5 months following maturation and provided an additional 19.8 months of usability. Fifty percent of prosthetic grafts could be used without intervention, while 25% were used only after revision and 25% were abandoned without being used. Grafts were accessed an average of 2.7 months after implantation and lasted 14.1 months after the initial cannulation. Twenty-three patients received a total of 52 catheters during the study, with an average implantation time of 6.5 months. Sixty-three percent of the catheters developed one or more complications, for a rate of 1.3 complications per year of indwelling catheter.

Conclusion

The current study provides a novel approach for the comprehensive evaluation of access care for patients undergoing hemodialysis through the development of a patient-centric approach to examine the complexities and shortcomings in dialysis access care. Despite some difficulties in achieving fistula maturation, an AVF prevalence rate was 66%, meeting the 65% goal set by the Fistula First Initiative. Unfortunately, a significant portion of the remainder of the dialysis support was provided by catheters, with a 27% catheter prevalence rate.

Impact of Lesion Morphology on Durability After Angioplasty of Failed Arteriovenous Fistulas in Hemodialysis Patients

PURPOSE

To investigate if morphological patterns of arteriovenous fistula (AVF) venous lesions affect primary patency after percutaneous transluminal angioplasty (PTA).

METHODS

From July 2014 to June 2015, 262 patients underwent PTA for failed AVFs. A total of 104 patients were excluded owing to (1) calcification or AVF occlusion precluding ultrasound examination, (2) central venous or arterial lesions, and (3) no follow-up, leaving 158 patients (mean age 71±12; 96 men) for analysis. More than half of the patients had one or more previous PTAs for the failed AVF. Prior to PTA the stenotic lesions were assessed using ultrasonography to determine stenotic patterns at the minimum lumen area site and to evaluate the flow volume in the brachial artery. Three stenotic patterns were identified: intimal hyperplasia (IH) stenosis (n=110), shrinking lumen stenosis (n=32), and venous valve-related stenosis (n=16). The main outcome measure was primary patency after PTA estimated using Kaplan-Meier analysis. Predictors for loss of primary patency were determined using a multivariate Cox proportional hazards model; the results are presented as the adjusted hazard ratio (HR) and 95% confidence interval (CI).

RESULTS

Median follow-up after PTA was 6.3 months (interquartile range 3.3, 10.5). The 6-month primary patency estimates were 56%±5% in the IH group, 40±9% in the shrinking lumen group, and 100% in the valve stenosis group (IH vs shrinking, p=0.013; IH vs valve, p=0.003). In multivariate analysis, shrinking lumen morphology had a negative impact on primary patency (HR 2.05, 95% CI 1.25 to 3.36, p=0.005), while venous valve-related stenosis had a positive impact (HR 0.19, 95% CI 0.04 to 0.79, p=0.023). Flow volume (10-mL/min increments; HR 0.97, 95% CI 0.96 to 0.99, p=0.004) and history of PTA (HR 1.66, 95% CI 1.06 to 2.60, p=0.029) were also independently associated with primary patency after PTA.

CONCLUSION

The patterns of AVF stenosis as determined by ultrasound can affect the outcome of treatment with balloon dilation.

Interventions for treating central venous haemodialysis catheter malfunction

BACKGROUND

Adequate haemodialysis (HD) in people with end-stage kidney disease (ESKD) is reliant upon establishment of vascular access, which may consist of arteriovenous fistula, arteriovenous graft, or central venous catheters (CVC). Although discouraged due to high rates of infectious and thrombotic complications as well as technical issues that limit their life span, CVC have the significant advantage of being immediately usable and are the only means of vascular access in a significant number of patients. Previous studies have established the role of thrombolytic agents (TLA) in the prevention of catheter malfunction. Systematic review of different thrombolytic agents has also identified their utility in restoration of catheter patency following catheter malfunction. To date the use and efficacy of fibrin sheath stripping and catheter exchange have not been evaluated against thrombolytic agents.

OBJECTIVES

This review aimed to evaluate the benefits and harms of TLA, preparations, doses and administration as well as fibrin-sheath stripping, over-the-wire catheter exchange or any other intervention proposed for management of tunnelled CVC malfunction in patients with ESKD on HD.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Specialised Register up to 17 August 2017 through contact with the Information Specialist using search terms relevant to this review. Studies in the Specialised Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal, and ClinicalTrials.gov.

SELECTION CRITERIA

We included all studies conducted in people with ESKD who rely on tunnelled CVC for either initiation or maintenance of HD access and who require restoration of catheter patency following late-onset catheter malfunction and evaluated the role of TLA, fibrin sheath stripping or over-the-wire catheter exchange to restore catheter function. The primary outcome was be restoration of line patency defined as ≥ 300 mL/min or adequate to complete a HD session or as defined by the study authors. Secondary outcomes included dialysis adequacy and adverse outcomes.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed retrieved studies to determine which studies satisfy the inclusion criteria and carried out data extraction. Included studies were assessed for risk of bias. Summary estimates of effect were obtained using a random-effects model, and results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes, and mean difference (MD) and 95% CI for continuous outcomes. Confidence in the evidence was assessed using GRADE.

MAIN RESULTS

Our search strategy identified 8 studies (580 participants) as eligible for inclusion in this review. Interventions included: thrombolytic therapy versus placebo (1 study); low versus high dose thrombolytic therapy (1); alteplase versus urokinase (1); short versus long thrombolytic dwell (1); thrombolytic therapy versus percutaneous fibrin sheath stripping (1); fibrin sheath stripping versus over-the-wire catheter exchange (1); and over-the-wire catheter exchange versus exchange with and without angioplasty sheath disruption (1). No two studies compared the same interventions. Most studies had a high risk of bias due to poor study design, broad inclusion criteria, low patient numbers and industry involvement.Based on low certainty evidence, thrombolytic therapy may restore catheter function when compared to placebo (149 participants: RR 4.05, 95% CI 1.42 to 11.56) but there is no data available to suggest an optimal dose or administration method. The certainty of this evidence is reduced due to the fact that it is based on only a single study with wide confidence limits, high risk of bias and imprecision in the estimates of adverse events (149 participants: RR 2.03, 95% CI 0.38 to 10.73).Based on the available evidence, physical disruption of a fibrin sheath using interventional radiology techniques appears to be equally efficacious as the use of a pharmaceutical thrombolytic agent for the immediate management of dysfunctional catheters (57 participants: RR 0.92, 95% CI 0.80 to 1.07).Catheter patency is poor following use of thrombolytic agents with studies reporting median catheter survival rates of 14 to 42 days and was reported to improve significantly by fibrin sheath stripping or catheter exchange (37 participants: MD -27.70 days, 95% CI -51.00 to -4.40). Catheter exchange was reported to be superior to sheath disruption with respect to catheter survival (30 participants: MD 213.00 days, 95% CI 205.70 to 220.30).There is insufficient evidence to suggest any specific intervention is superior in terms of ensuring either dialysis adequacy or reduced risk of adverse events.

AUTHORS' CONCLUSIONS

Thrombolysis, fibrin sheath disruption and over-the-wire catheter exchange are effective and appropriate therapies for immediately restoring catheter patency in dysfunctional cuffed and tunnelled HD catheters. On current data there is no evidence to support physical intervention over the use of pharmaceutical agents in the acute setting. Pharmacological interventions appear to have a bridging role and long-term catheter survival may be improved by fibrin sheath disruption and is probably superior following catheter exchange. There is no evidence favouring any of these approaches with respect to dialysis adequacy or risk of adverse events.The current review is limited by the small number of available studies with limited numbers of patients enrolled. Most of the studies included in this review were judged to have a high risk of bias and were potentially influenced by pharmaceutical industry involvement.Further research is required to adequately address the question of the most efficacious and clinically appropriate technique for HD catheter dysfunction.

Effectiveness of Quality Improvement Strategies for the Management of CKD: A Meta-Analysis

BACKGROUND AND OBJECTIVES

Quality improvement interventions have enhanced care for other chronic illnesses, but their effectiveness for patients with CKD is unknown. We sought to determine the effects of quality improvement strategies on clinical outcomes in adult patients with nondialysis-requiring CKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We conducted a systematic review of randomized trials, searching Medline and the Cochrane Effective Practice and Organization of Care database from January of 2003 to April of 2015. Eligible studies evaluated one or more of 11 prespecified quality improvement strategies, and prespecified study outcomes included at least one process of care measure, surrogate outcome, or hard clinical outcome. We used a random effects model to estimate the pooled risk ratio (RR; dichotomous data) or the mean difference (continuous data).

RESULTS

We reviewed 15 patient-level randomized trials (n=3298 patients), and six cluster-randomized trials (n=30,042 patients). Quality improvement strategies reduced dialysis incidence (seven trials; RR, 0.85; 95% confidence interval [95% CI], 0.74 to 0.97) and LDL cholesterol concentrations (four trials; mean difference, -17.6 mg/dl; 95% CI, -28.7 to -6.5), and increased the likelihood that patients received renin-angiotensin-aldosterone system inhibitors (nine trials; RR, 1.16; 95% CI, 1.06 to 1.27). We did not observe statistically significant effects on mortality, cardiovascular events, eGFR, glycated hemoglobin, and systolic or diastolic BP.

CONCLUSIONS

Quality improvement interventions yielded significant beneficial effects on three elements of CKD care. Estimates of the effectiveness of quality improvement strategies were limited by study number and adherence to quality improvement principles.

PODCAST

This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2017_09_06_CJASNPodcast_17_10.mp3.

Effect of the timing of dialysis initiation on left ventricular hypertrophy and ınflammation in pediatric patients

BACKGROUND

The optimal time for dialysis initiation in adults and children with chronic kidney disease remains unclear. The aim of this study was to evaluate the impact of dialysis timing on different outcome parameters, in particular left ventricular (LV) morphology and inflammation, in pediatric patients receiving peritoneal dialysis and hemodialysis.

METHODS

The medical records of pediatric dialysis patients who were followed-up in nine pediatric nephrology centers in Turkey between 2008 and 2013 were retrospectively reviewed. In addition to demographic data, we retrieved anthropometric measurements, data on dialysis treatment modalities, routine biochemical parameters, complete blood count, serum ferritin, parathormone, C-reactive protein (CRP), and albumin levels, as well as echocardiographic data and hospitalization records. The patients were divided into two groups based on their estimated glomerular filtration rate (eGFR) levels at dialysis initiation, namely, an early-start group, characterized by an eGFR of >10 ml/min/1.73 m², and a late-start group, with an eGFR of < 7 ml/min/1.73 m². The collected data were compared between these groups.

RESULTS

A total of 245 pediatric dialysis patients (mean age ± standard deviation 12.3 ± 5.1 years, range 0.5-21 years) were enrolled in this study. Echocardiographic data were available for 137 patients, and the mean LV mass index (LVMI) was 58 ± 31 (range 21-215) g/m^2.7. The LVMI was 75 ± 30 g/m^2.7(n = 81) and 34 ± 6 g/m^2.7(n = 56) in patients with or without LV hypertrophy (LVH) (p < 0.001). Early-start (eGFR >10 ml/min/1.73 m²) versus late-start dialysis (eGFR < 7 ml/min/1.73 m²) groups did not significantly differ in LVMI and LVH status (p > 0.05) nor in number of hospitalizations. Serum albumin levels were significantly higher in the early-dialysis group compared with the late-dialysis group (3.3 ± 0.7 vs. 3.1 ± 0.7 g/dl, respectively; p < 0.05). The early-start group had relatively higher time-averaged albumin levels (3.2 ± 0.5 vs. 3.1 ± 0.5 g/dl; p = > 0.05) and relatively lower CRP levels (3.64 ± 2.00 vs. 4.37 ± 3.28 mg/L, p > 0.05) than the late-start group, but these differences did not reach statistical significance.

CONCLUSION

Although early dialysis initiation did not have a significant effect on important clinical outcome parameters, including LVH, inflammatory state, and hospitalization, in our pediatric dialysis patients, this area of study deserves further attention.

Attitudes and Opinions of Canadian Nephrologists Toward Continuous Quality Improvement Options

BACKGROUND AND OBJECTIVES

A shift to holding individual physicians accountable for patient outcomes, rather than facilities, is intuitively attractive to policy makers and to the public. We were interested in nephrologists' attitudes to, and awareness of, quality metrics and how nephrologists would view a potential switch from the current model of facility-based quality measurement and reporting to publically available reports at the individual physician level.

DESIGN SETTING PARTICIPANTS AND MEASUREMENTS

The study was conducted using a web-based survey instrument (Online Appendix 1). The survey was initially pilot tested on a group of 8 nephrologists from across Canada. The survey was then finalized and e-mailed to 330 nephrologists through the Canadian Society of Nephrology (CSN) e-mail distribution list. The 127 respondents were 80% university based, and 33% were medical/dialysis directors.

RESULTS

The response rate was 43%. Results demonstrate that 89% of Canadian nephrologists are engaged in efforts to improve the quality of patient care. A minority of those surveyed (29%) had training in quality improvement. They feel accountable for this and would welcome the inclusion of patient-centered metrics of care quality. Support for public reporting as an effective strategy on an individual nephrologist level was 30%.

CONCLUSIONS

Support for public reporting of individual nephrologist performance was low. The care of nephrology patients will be best served by the continued development of a critical mass of physicians trained in patient safety and quality improvement, by focusing on patient-centered metrics of care delivery, and by validating that all proposed new methods are shown to improve patient care and outcomes.

Fistula First Initiative: Historical Impact on Vascular Access Practice Patterns and Influence on Future Vascular Access Care

The vascular access is the lifeline for the hemodialysis patient. In the United States, the Fistula First Breakthrough Initiative (FFBI) has been influential in improving use of arteriovenous fistulas (AVF) in prevalent hemodialysis patients. Currently, prevalent AVF rates are near the goal of 66% set forth by the original FFBI. However, central venous catheter (CVC) rates remain very high in the United States in patients initiating hemodialysis, nearly exceeding 80%. A new direction of the of the FFBI has focused on strategies to reduce CVC use, and subsequently the FFBI has now been renamed the "Fistula First-Catheter Last Initiative". However, an AVF may not be the best vascular access in all hemodialysis patients, and arteriovenous grafts (AVG) and CVCs may be appropriate and the best access for a subset of hemodialysis patients. Unfortunately, there still remains very little emphasis within vascular access initiatives and guidelines directed towards evaluation of the individual patient context, specifically patients with poor long-term prognoses and short life expectancies, patients with multiple comorbidities, patients who are more likely to die than reach end stage renal disease (ESRD), and patients of elderly age with impaired physical and cognitive function. Given the complexity of medical and social issues in advanced CKD and ESRD patients, planning, selection, and placement of the most appropriate vascular access are ideally managed within a multidisciplinary setting and requires consideration of several factors including national vascular access guidelines. Thus, the evolution of the FFBI should underscore the need for multidisciplinary health teams with a major emphasis placed on "the right access for the right patient" and improving the patient's overall quality of life.

Antibiotic Lock in Tenckhoff Catheter for Biofilm-Associated Peritonitis

Biofilm bacteria in the Tenckhoff catheter are notoriously difficult to eradicate. They are the potential sources of relapsing or repeat peritonitis among peritoneal dialysis (PD) patients. Inadequate penetration into biofilms by standard intraperitoneal antibiotics, as well as a lack of effective adjunctive treatment, leads to a high rate of Tenckhoff catheter loss as a result of biofilm bacteria. In hemodialysis, on the other hand, catheter-related bloodstream infection caused by biofilm bacteria does not necessarily lead to a loss of catheter. Here, the use of antibiotic lock in conjunction with systemic antibiotics has been shown to be an effective treatment. In this case report, we present 2 cases of biofilm-associated PD peritonitis. The success in salvaging the Tenckhoff catheters by antibiotic lock suggested a potentially similar efficacy in PD patients using this adjunctive treatment, which has not been thoroughly investigated in the literature. Relevant clinical trials are necessary to evaluate whether antibiotic lock is also effective in eradicating biofilm bacteria in the Tenckhoff catheter.

Endovascular Proximal Forearm Arteriovenous Fistula for Hemodialysis Access: Results of the Prospective, Multicenter Novel Endovascular Access Trial (NEAT)

BACKGROUND

Hemodialysis arteriovenous fistulas (AVFs) are suboptimally used primarily due to problems with maturation, early thrombosis, and patient nonacceptance. An endovascular approach to fistula creation without open surgery offers another hemodialysis vascular access option.

STUDY DESIGN

Prospective, single-arm, multicenter study (Novel Endovascular Access Trial [NEAT]).

SETTINGS & PARTICIPANTS

Consecutive adult non-dialysis-dependent and dialysis-dependent patients referred for vascular access creation at 9 centers in Canada, Australia, and New Zealand.

INTERVENTION

Using catheter-based endovascular technology and radiofrequency energy, an anastomosis was created between target vessels, resulting in an endovascular AVF (endoAVF).

OUTCOMES

Safety, efficacy, functional usability, and patency end points.

MEASUREMENTS

Safety as percentage of device-related serious adverse events; efficacy as percentage of endoAVFs physiologically suitable (brachial artery flow ≥ 500mL/min, vein diameter ≥ 4mm) for dialysis within 3 months; functional usability of endoAVFs to provide prescribed dialysis via 2-needle cannulation; primary and cumulative endoAVF patencies per standardized definitions.

RESULTS

80 patients were enrolled (20 roll-in and 60 participants in the full analysis set; the latter are reported). EndoAVFs were created in 98% of participants; 8% had a serious procedure-related adverse event (2% device related). 87% were physiologically suitable for dialysis (eg, mean brachial artery flow, 918mL/min; endoAVF vein diameter, 5.2mm [cephalic vein]). EndoAVF functional usability was 64% in participants who received dialysis. 12-month primary and cumulative patencies were 69% and 84%, respectively.

LIMITATIONS

Due to the unique anatomy and vessels used to create endoAVFs, this was a single-arm study without a surgical comparator.

CONCLUSIONS

An endoAVF can be reliably created using a radiofrequency magnetic catheter-based system, without open surgery and with minimal complications. The endoAVF can be successfully used for hemodialysis and demonstrated high 12-month cumulative patencies. It may be a viable alternative option for achieving AVFs for hemodialysis patients in need of vascular access.

Catheterization via direct cannulation of superior vena cava for a hemodialysis patient with an original dysfunctional catheter on the left internal jugular vein

Establishing a long-term vascular access in patients exhibiting vascular access exhaustion is challenging. In this study, we reported a case of a direct catheterization in the superior vena cava of a hemodialysis patient with vascular access exhaustion and original dysfunctional catheter inserted via the left internal jugular vein. The direct catheterization was performed with cuffed tunnel catheter (CUFF) and guided by digital subtraction angiography (DSA) and multidetector computed tomography venography (MDCTV). The DSA and MDCTV results revealed an occlusion in the right innominate vein and thromboses in the left innominate, right internal jugular, subclavian, and femoral veins. The distal end of the superior vena cava was localized clearly by the original CUFF under DSA. Directed at the distal end of the superior vena cava, a 0.5-cm secondary puncture was introduced below the lateral head of the sternocleidomastoid muscle via the right neck area. This study is one of the few reports regarding direct catheterization of CUFF via the superior vena cava of a patient with vascular access exhaustion and CUFF dysfunction on the left internal jugular vein.We believe that our study can provide a new alternative for inserting central venous catheter for such patient.

Ultrasound Vector Flow Imaging – could be a new tool in evaluation of arteriovenous fistulas for hemodialysis?

Introduction

We report the use of a new ultrasound technique to evaluate the axial and lateral components of a complex flow in the arteriovenous fistula (AVF). Vector Flow Imaging (VFI) allows to identify different components of the flow in every direction, even orthogonal to the flow streamline, represented by many single vectors. VFI could help to identify flow alterations in AVF, probably responsible for its malfunction.

Methods

From February to June 2016, 14 consecutive patients with upper-limb AVF were examined with a Resona 7 (Mindray, Shenzhen, China) ultrasound scanner equipped with VFI. An analysis of mean velocity, angular direction and mean number of vectors impacting the vessel wall was carried out. We also identified main flow patterns present in the arterial side, into the venous aneurysm and in correspondence of significant stenosis.

Results

A disturbed flow with the presence of vectors directed against the vessel walls was found in 9/14 patients (64.28%): in correspondence of the iuxta-anastomotic venous side (4/9; 44.4%), into the venous aneurysmal tracts (3/9; 33.3%) and in concomitance of stenosis (2/9; 22.2%). The mean velocity of the vectors was around 20-25 cm/s, except in presence of stenosis, where the velocities were much higher (45-50 cm/s). The vectors directed against the vessel walls presented high angle attack (from 45° to 90°, with a median angular deviation 65°).

Conclusions

VFI was confirmed to be an innovative and intuitive imaging technology to study the flow complexity in the arteriovenous fistulas.

Clinical safety and performance of VIVIA: a novel home hemodialysis system

Background

The VIVIA Hemodialysis System (Baxter Healthcare Corporation, Deerfield, IL, USA) was designed for patient use at home to reduce the burden of treatment and improve patient safety. It has unique features including extended use of the dialyzer and blood set through in situ hot-water disinfection between treatments; generation of on-line infusible-quality dialysate for automated priming, rinseback and hemodynamic support during hypotension and a fully integrated access disconnect sensor.

Methods

The safety and performance of VIVIA were assessed in two clinical studies. A first-in-man study was a prospective, single-arm study that involved 22 prevalent hemodialysis (HD) patients who were treated for ∼4 h, four times a week, for 10 weeks. A second clinical study was a prospective, single-arm study (6-8 h of dialysis treatment at night three times a week) that involved 17 prevalent patients treated for 6 weeks.

Results

There were 1114 treatments from the two studies (first-in-man study, 816; extended duration study, 298). Adverse events (AEs) were similar in the two studies to those expected for prevalent HD patients. No deaths and no device-related serious AEs occurred. Adequacy of dialysis ( Kt / V ) urea in both clinical trials was well above the clinical guidelines. VIVIA performed ultrafiltration accurately as prescribed in the two studies. The majority of patients achieved 10 or more uses of the dialyzer. Endotoxin levels and bacterial dialysate sampling met infusible-quality dialysate standards.

Conclusion

These results confirm the safety and expected performance of VIVIA.

When Is Parenteral Nutrition Appropriate?

Parenteral nutrition (PN) represents one of the most notable achievements of modern medicine, serving as a therapeutic modality for all age groups across the healthcare continuum. PN offers a life-sustaining option when intestinal failure prevents adequate oral or enteral nutrition. However, providing nutrients by vein is an expensive form of nutrition support, and serious adverse events can occur. In an effort to provide clinical guidance regarding PN therapy, the Board of Directors of the American Society for Parenteral and Enteral Nutrition (ASPEN) convened a task force to develop consensus recommendations regarding appropriate PN use. The recommendations contained in this document aim to delineate appropriate PN use and promote clinical benefits while minimizing the risks associated with the therapy. These consensus recommendations build on previous ASPEN clinical guidelines and consensus recommendations for PN safety. They are intended to guide evidence-based decisions regarding appropriate PN use for organizations and individual professionals, including physicians, nurses, dietitians, pharmacists, and other clinicians involved in providing PN. They not only support decisions related to initiating and managing PN but also serve as a guide for developing quality monitoring tools for PN and for identifying areas for further research. Finally, the recommendations contained within the document are also designed to inform decisions made by additional stakeholders, such as policy makers and third-party payers, by providing current perspectives regarding the use of PN in a variety of healthcare settings.

ESRD Databases, Public Policy, and Quality of Care: Translational Medicine and Nephrology

Efforts to improve care of patients with ESRD and the policies that guide those activities depend on evidence-based best practices derived from clinical trials and carefully conducted observational studies. Our review describes this process in the context of the translational research model (bench to bedside to populations), with a particular emphasis on bedside care. We illustrate some of its accomplishments and describe the limitations of the data and evidence supporting policy and practice.

Comparison of short-term efficacy of iron sucrose with those of ferric chloride in hemodialysis patients: An open-label study

Background:

It is intriguing and imperative that the comparison of the iron preparations in hemodialysis (HD) patients. This study aimed to observe the short-term efficacy of parenteral iron sucrose and ferric chloride in HD patients.

Materials and Methods:

This was a consecutive 10-week single-blind study in Taiwan. An intravenous iron supplement of 100 mg/week was administered as an infusion in 100 ml of normal saline, until a total dose of 1000 mg was achieved. The primary outcome was evaluated by the changes in serum hematocrit (Hct) levels. The changes in serum Hct and iron indices were evaluated every 2 weeks for 10 weeks. The results were collected from 21 April to 4 July 2013.

Results:

A total of 56 HD patients completed the study. Subjects were randomized into an iron sucrose group (26 patients) and a ferric chloride group (30 patients). Between the two treatment groups, there were no statistically significant differences in the change in serum Hct, ferritin, iron, or total iron binding capacity (P > 0.05). In the iron sucrose group, the increase in Hct levels was statistically significant at weeks 4, 8, and 10. In the ferric chloride group, the increase in Hct levels was statistically significant at week 8. No obvious major side effects were observed in both groups.

Conclusion:

In the study subjects, parenteral iron sucrose was as effective and safe as ferric chloride for treating anemia in HD patients.

Post-transplant blood transfusions and pediatric renal allograft outcomes

The association of blood transfusions with GS after pediatric KTx is unclear. We retrospectively analyzed blood transfusions post-KTx and subsequent outcomes. Between 1984 and 2013, 482 children (<18 years of age) underwent KTx at our center. Recipient demographics, outcomes and transfusion data were collected. Cox regression with post-KTx blood transfusion as a time-dependent covariate was performed to model the impact of blood transfusion on outcomes. Of the 208 (44%) that were transfused, 39% had transfusion <1 month post-KTx; 48% >12 months. Transfused and non-transfused recipients were not significantly different. In univariate and multivariate analyses, there was no difference between transfused and non-transfused recipient patient survival, antibody-mediated and ACR, and DSA free survival. Transfusions <1 month post-KTx did not impact DCGS (P=NS). Patients transfused >12 months post-KTx had significantly lower 12 month eGFR (compared to non-transfused) and worse subsequent DCGS. Post-KTx blood transfusions have increased in pediatric KTx over time but have no negative association with rejection or DSA production. DCGS is unaffected by transfusion within first month. Transfusions after the first year occur in patients with more advanced chronic kidney disease and are associated with significantly worse DCGS.

The impact of haemodialysis arteriovenous fistula on haemodynamic parameters of the cardiovascular system

BACKGROUND

Satisfactory vascular access flow (Qa) of an arteriovenous fistula (AVF) is necessary for haemodialysis (HD) adequacy. The aim of the present study was to further our understanding of haemodynamic modifications of the cardiovascular system of HD patients associated with an AVF. The main objective was to calculate using real data in what way an AVF influences the load of the left ventricle (LLV).

METHODS

All HD patients treated in our dialysis unit and bearing an AVF were enrolled into the present observational cross-sectional study. Fifty-six patients bore a lower arm AVF and 30 an upper arm AVF. Qa and cardiac output (CO) were measured by means of the ultrasound dilution Transonic Hemodialysis Monitor HD02. Mean arterial pressure (MAP) was calculated; total peripheral vascular resistance (TPVR) was calculated as MAP/CO; resistance of AVF (AR) and systemic vascular resistance (SVR) are connected in parallel and were respectively calculated as AR = MAP/Qa and SVR = MAP/(CO - Qa). LLV was calculated on the principle of a simple physical model: LLV (watt) = TPVR·CO(2). The latter was computationally divided into the part spent to run Qa through the AVF (LLVAVF) and that part ensuring the flow (CO - Qa) through the vascular system. The data from the 86 AVFs were analysed by categorizing them into lower and upper arm AVFs.

RESULTS

Mean Qa, CO, MAP, TPVR, LLV and LLVAVF of the 86 AVFs were, respectively, 1.3 (0.6 SD) L/min, 6.3 (1.3) L/min, 92.7 (13.9) mmHg, 14.9 (3.9) mmHg·min/L, 1.3 (0.6) watt and 19.7 (3.1)% of LLV. A statistically significant increase of Qa, CO, LLV and LLVAVF and a statistically significant decrease of TPVR, AR and SVR of upper arm AVFs compared with lower arm AVFs was shown. A third-order polynomial regression model best fitted the relationship between Qa and LLV for the entire cohort (R (2) = 0.546; P < 0.0001) and for both lower (R (2) = 0.181; P < 0.01) and upper arm AVFs (R (2) = 0.663; P < 0.0001). LLVAVF calculated as % of LLV rose with increasing Qa according to a quadratic polynomial regression model, but only in lower arm AVFs. On the contrary, no statistically significant relationship was found between the two parameters in upper arm AVFs, even if mean LLVAVF was statistically significantly higher in upper arm AVFs (P < 0.0001).

CONCLUSIONS

Our observational cross-sectional study describes statistically significant haemodynamic modifications of the CV system associated to an AVF. Moreover, a quadratic polynomial regression model best fits the relationship between LLVAVF and Qa, but only in lower arm AVFs.