Lessons From International Differences in Vascular Access Practices and Outcomes

Is there a role of the kidney failure risk equation in optimizing timing of vascular access creation in pre-dialysis patients?

BACKGROUND

The aims of this study were to assess the utility of using the Kidney Failure Risk Equation (KFRE) as an indicator to guide timing of vascular access creation in pre-dialysis patients.

MATERIALS AND METHODS

Patients referred for vascular access creation had KFRE calculated at the time of assessment and compared to standard criteria for referral. Receiver operating characteristic curves were produced for each parameter. The outcomes at 3 months, 6 months, and 1 year were used as time points for analysis.

RESULTS

Two hundred and three patients were assessed, and full data sets were available on 190 (94.6%). Access was created in 156 patients (82.1%) with a fistula in 153 (98.7%). Only 65.7% initiated dialysis within the follow up period. Those patients with an AV access created (n = 156) 37 (23.7%) did not reach end stage over the entire follow up period. Of the remaining patients (n = 119) that reached end stage 72.2% (n = 86) started on an AVF/AVG and 27.7% (n = 33) on a CVC. Using ROC analysis for referral eGFR, ACR and KFRE predicting dialysis initiation predictors resulted in C statistics for eGFR, ACR, and KFRE2 of 0.68 (0.58-0.79), 0.75 (0.65-0.84), and 0.72 (0.62-0.81) at 3 months; 0.73 (0.65-0.81), 0.70 (0.62-0.78), and 0.75 (0.67-0.81) at 6 months; and 0.65 (0.57-0.72); 0.67 (0.59-0.75), and 0.68 (0.61-0.77) at 12 months.

CONCLUSIONS

In a group of patients referred for vascular access creation the predictive models are relatively poor when applied to initiation of dialysis. The application of current guidelines to fistula creation appears to result in a high rate of unnecessary fistula formation and non-use. The study requires further evaluation in a test set of patients to confirm these findings and also identify where such risk based approaches may need modification.

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

PURPOSE

International guidelines recommend screening for arteriovenous fistula (AVF) stenosis using various non-invasive methods. We evaluate different non-invasive AVF flow measurements for detecting AVF stenosis.

METHODS

Twenty-three haemodialysis patients with suspected AVF stenosis are enrolled based on abnormal physical signs or high venous pressure during dialysis. Ultrasound dilution, urea dilution, Doppler ultrasonography, and fistulography are performed on all patients. The accuracy of three non-invasive methods is compared.

RESULTS

Fistulography reveals AVF stenosis in 18 patients, 12 of whom have severe stenosis (greater than 50% stenosis in diameter). Concerning the location of the stenosis lesions, eight are at the inflow site, six at the outflow site, and four on both sites. Receiver operating characteristic curve analysis shows that Doppler ultrasonography has a high discriminative ability and the averaged areas under the curves are 0.933 (95% confidence interval [CI]; 0.81 to 0.99) for stenosis and 0.929 (95% CI 0.82-0.99) for severe stenosis. The sensitivity of each method for the prediction of access stenosis using ultrasound dilution, urea dilution, and Doppler ultrasonography is 73%, 73%, and 80%, respectively. The respective specificity of each method is 40%, 80%, and 100%, respectively. Physical examination (PE) shows an 80% sensitivity and 80% specificity in the detection of AVF stenosis. The combination of Doppler ultrasound with PE produces the highest sensitivity (93%) for detecting AVF stenosis.

CONCLUSIONS

Doppler ultrasound combined with physical examination is more accurate than other non-invasive methods for detecting AVF stenosis.

Global Epidemiology of End-Stage Kidney Disease and Disparities in Kidney Replacement Therapy

BACKGROUND

The global epidemiology of end-stage kidney disease (ESKD) reflects each nation's unique genetic, environmental, lifestyle, and sociodemographic characteristics. The response to ESKD, particularly regarding kidney replacement therapy (KRT), depends on local disease burden, culture, and socioeconomics. Here, we explore geographic variation and global trends in ESKD incidence and prevalence and examine variations in KRT modality, practice patterns, and mortality. We conclude with a discussion on disparities in access to KRT and strategies to reduce ESKD global burden and to improve access to treatment in low- and middle-income countries (LMICs).

SUMMARY

From 2003 to 2016, incidence rates of treated ESKD were relatively stable in many higher income countries but rose substantially predominantly in East and Southeast Asia. The prevalence of treated ESKD has increased worldwide, likely due to improving ESKD survival, population demographic shifts, higher prevalence of ESKD risk factors, and increasing KRT access in countries with growing economies. Unadjusted 5-year survival of ESKD patients on KRT was 41% in the USA, 48% in Europe, and 60% in Japan. Dialysis is the predominant KRT in most countries, with hemodialysis being the most common modality. Variations in dialysis practice patterns account for some of the differences in survival outcomes globally. Worldwide, there is a greater prevalence of KRT at higher income levels, and the number of people who die prematurely because of lack of KRT access is estimated at up to 3 times higher than the number who receive treatment. Key Messages: Many people worldwide in need of KRT as a life-sustaining treatment do not receive it, mostly in LMICs where health care resources are severely limited. This large treatment gap demands a focus on population-based prevention strategies and development of affordable and cost-effective KRT. Achieving global equity in KRT access will require concerted efforts in advocating effective public policy, health care delivery, workforce capacity, education, research, and support from the government, private sector, nongovernmental, and professional organizations.

WavelinQ created arteriovenous fistulas versus surgical radiocephalic arteriovenous fistulas? A single-centre observational study

Purpose:

Devices to permit percutaneous endovascular arteriovenous fistula formation have recently been introduced into clinical practice with promising initial evidence. As guidelines support a distal fistula first policy, the question of whether an endovascular arteriovenous fistula should be performed as an initial option is introduced. The aims of this study were to compare a matched cohort of endovascular arteriovenous fistula with surgical radiocephalic arteriovenous fistulas.

Materials and methods:

Using data from a prospectively collected database over a 3-year period, a matched comparative analysis was performed.

Results:

WavelinQ arteriovenous fistulas (group W, n = 30) were compared with radiocephalic arteriovenous fistulas (group RC; n = 40). Procedural success was high with 96.7% for group W and 92.6% for group RC. Primary patency at 6 and 12 months was greater in group W (65.5% 6mo and 56.5% 12mo) compared to group RC (53.4% 6mo and 44% 12mo) ( p = 0.69 and 0.63). Mean primary patency was significantly lower for RC (235 ± 210 days) vs W (362 ± 240 days) ( p < 0.05). Secondary patency for group W was 75.8% and 69.5% at 6 and 12 months, respectively. Secondary patency for RC was lower at 66.7% and 57.6% at 6 and 12 months, respectively.

Conclusion:

Outcomes of WavelinQ arteriovenous fistulas in this series are similar to published results. When compared to a contemporaneously created group of surgical fistulas, WavelinQ demonstrated superior outcomes. These data would support that WavelinQ endovascular arteriovenous fistulas may be considered as a first option in the access pathway particularly if vessels at the wrist are absent or less than ideal.