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

BACKGROUND AND OBJECTIVES: Autologous arteriovenous fistula (AVF) is the best vascular access for hemodialysis. Distal forearm radiocephalic fistula is the best option, although the primary failure rate ranges from 20% to 50%. The main objective of the PHYSICALFAV trial was to evaluate the effect of preoperative isometric exercise on vascular caliber, percentage of distal arteriovenous fistula, and primary failure rate. DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS: The PHYSICALFAV trial (NCT03213756) is an open-label, multicenter, prospective, randomized, controlled trial (RCT). A total of 138 patients were randomized 1:1 to the exercise group (exercises combining a handgrip device and an elastic band for 8 weeks) or the control group (no exercise) and followed up with periodic Doppler ultrasound (DU) examinations. RESULTS: After 8 weeks of preoperative isometric exercise, in the exercise group, significant increases were detected in venous caliber (2.80 ± 0.95 mm vs 3.52 ± 0.93 mm [p < 0.001]), arterial caliber (2.61 ± 0.82 mm vs 2.74 ± 0.80 mm [p = 0.008]), arterial peak systolic velocity (66.34 ± 19.2 cm/s vs 71.03 ± 21.5 cm/s [p 0.043]), and maximum strength (28.35 ± 9.16 kg vs 32.68 ± 10.8 kg [p < 0.001]). Distal radiocephalic fistulas were performed in 75% of the exercise group patients compared with 50.8% in the control group (p = 0.030). The global primary failure rate was very low in both groups (7% exercise group vs 14% control group [p = 0.373]). CONCLUSION: Isometric preoperative exercise can improve vascular caliber and increase the possibility of performing distal arteriovenous fistula, with no significant differences in primary failure rate.

Removal capacity of different high-flux dialyzers during postdilution online hemodiafiltration.

INTRODUCTION: The aim of this study is to compare molecule removal and albumin leakage in postdilution online hemodiafiltration with different high-flux dialyzers. METHODS: We studied seven high-flux dialyzers (Polyflux 210H®, Evodial 2.2®, FxCordiax1000®, Elisio21H®, TS-2.1SL®, XevontaHi20®, VitaPES 210-HF®) in 6 patients. The reduction ratio (RR) of small- and middle-sized molecules was calculated. Dialysate samples were collected to estimate the albumin leakage. FINDINGS: Global differences between dialyzers were observed in the RR of ß2 microglobulin (P =0.003) and prolactin (P =0.013). The mean loss of albumin in the dialysate per session varied between 114 ± 67 mg (with Evodial 2.2) and 2621 ± 1363 mg per session (with XevontaHi20). We found global differences between dialyzers in total albumin loss (P = 0.05). DISCUSSION: We demonstrated that the performance of high-flux dialyzers was different among the types and that not all high-flux dialyzers should be considered equal.

Vascular access clinic results before and after implementing a multidisciplinary approach adding routine Doppler ultrasound. / Consulta de acceso vascular: resultados antes y después de la instauración de un programa multidisciplinar con realización de ecografía doppler de rutina.

BACKGROUND: A multidisciplinary approach and Doppler ultrasound (DU) assessment for the creation and maintenance of arteriovenous fistulas (AVF) for haemodialysis can improve prevalence and patency. The aim of this study was to analyse the impact of a new multidisciplinary vascular access (VA) clinic with routine DU. MATERIAL AND METHODS: We analysed the VA clinic results from 2014 and 2015, before and after the implementation of a multidisciplinary team protocol (vascular surgeon/nephrologist) with routine DU in preoperative mapping and prevalent AVF. RESULTS: We analysed 345 and 364 patients from 2014 and 2015 respectively. The number of surgical interventions was similar in both periods (p=.289), with a trend towards an increase in preventive surgical repair of AVF in 2015 (17 vs. 29, p=.098). 155 vs. 169 new AVF were performed in 2014 and 2015, with a significantly lower primary failure rate in 2015 (26.4 vs. 15.3%, p=.015), and a non-significant increase in radiocephalic AVF, 25.8 vs. 33.2% (n=40 vs. 56), p=.159. The concordance between the indication at the clinic and the surgery performed also increased (81.3 vs. 93.5%, p=.001). Throughout 2015 fewer complementary imaging test were requested from the clinic (78 vs. 35, p <.001), with a corresponding reduction in costs (€87,716 vs. €59,445). CONCLUSIONS: Multidisciplinary approach with routine DU can improve VA results, with a decrease in primary failure rate, higher likelihood of radiocephalic AVF, better management of dis-functioning AVF and lower radiological test costs.

Factors related with the progression of chronic kidney disease.

BACKGROUND: Our aims were to determine the rate of progression of chronic kidney disease (CKD) and to identify predictors, with particular emphasis on bone and mineral metabolism. METHODS: Retrospective and observational study including 300 patients with advanced CKD (61.2% males, 33.1% diabetics; age 65.6±14 years). Mean follow-up time was 19.4±10.1 months. Baseline estimated glomerular filtration rate (eGFR) (MDRD-4) was 22.5±7.18 mL/min. To calculate the rate of decline in eGFR, we used the slope of the regression line between all determinations of eGFR and follow-up time. We calculated the mean values for proteinuria and serum phosphate, calcium, uric acid, and PTH, as well as 24-hour urinary excretion of urea nitrogen over time for each patient. Follow-up was at least 6 months and included at least 4 measurements of eGFR. RESULTS: The mean rate of decline eGFR (-1.64 mL/min/1.73 m²/year) was inversely correlated with serum phosphate levels (4.3±2.1 mg/dL, P<.001), PTH (256.3±193.7 ng/L, p<.001) and proteinuria (0.84±1.31 g/day, P=.004) and directly correlated with mean serum calcium (P<.001) and the presence of hypertension (P<.02). However, only serum phosphate, serum PTH, and proteinuria persisted as predictors in the multivariate analysis. Stable-GFR patients (positive slope) were older (P=.041) and had lower serum phosphate and PTH levels (P<.01 and P<.01 respectively) and lower proteinuria (P<.01). CONCLUSIONS: The rate of decrease in eGFR was correlated with serum phosphate and PTH levels and proteinuria. All of these factors can be modified with an adequate treatment.