Impact of surgeon factor on radiocephalic fistula patency rates

Upper limb exercise for arteriovenous fistula maturation in people requiring permanent haemodialysis access

BACKGROUND

The failure of arteriovenous fistulas (AVF) to mature is a major problem in patients with kidney failure who require haemodialysis (HD). Preoperative planning is an important factor in increasing functional AVF. Upper limb exercise has been recommended to gain AVF maturation. Studies of pre- and post-operative upper limb exercises in patients with kidney failure patients have been reported; however, the optimal program for this population is unknown due to inconsistent results among these programs.

OBJECTIVES

We aimed to determine if upper limb exercise would be beneficial for AVF maturation (prior to and post AVF creation) in patients with kidney failure and to improve AVF outcomes. This review also aimed to identify adverse events related to upper limb exercise.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 15 March 2022 through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov, and other resources (e.g. reference list, contacting relevant individuals, and grey literature).

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs, comparing upper limb exercise training programs with no intervention or other control programs before or after AVF creation in patients with kidney failure. Outcome measures included time to mature, ultrasound and clinical maturation, venous diameter, blood flow in the inflow artery, dialysis efficacy indicator, vascular access function (functional AVF), vascular access complications, and adverse events.

DATA COLLECTION AND ANALYSIS

Study selection and data extraction were taken by four independent authors. Bias assessment and quality assessment were undertaken independently by two authors. The effect estimate was analysed using risk ratio (RR) with 95% confidence intervals (CI) for dichotomous data, or mean difference (MD) or standardised mean difference (SMD) for continuous data. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

Nine studies (579 participants) were included, and seven studies (519 participants) conducting post-operative exercise training could be meta-analysed. Three comparisons were undertaken: (i) isotonic exercise training versus no intervention; (ii) isometric versus isotonic exercise training; and (iii) isotonic (high volume) versus isotonic exercise training (low volume). Due to insufficient data, we could not analyse pre-operative exercise training. Overall, the risk of bias was low for selection and reporting bias, high for performance and attrition bias, and unclear for detection bias. Compared to no intervention, isotonic exercise training may make little or no difference to ultrasound maturation (2 studies, 263 participants: RR 1.09, 95% CI 0.94 to 1.25; I² = 0%; low certainty evidence), but may improve clinical maturation (2 studies, 263 participants: RR 1.14, 95% CI 1.02 to 1.27; I² = 0%; low certainty evidence). Compared to isotonic exercise training, isometric exercise training may improve both ultrasound maturation (3 studies, 160 participants: RR 1.56, 95% CI 1.21 to 2.00; I² = 22%; low certainty evidence) and clinical maturation (3 studies, 160 participants: RR 1.80, 95% CI 1.18 to 2.76; I² = 53%; low certainty evidence). Venous diameter (3 studies, 160 participants: MD 0.84 mm, 95% CI 0.45 to 1.23; I² = 0%; low certainty evidence) and blood flow in the inflow artery (3 studies, 160 participants: MD 140.62 mL/min, 95% CI 38.72 to 242.52; I² = 0%; low certainty evidence) may be greater with isometric exercise training. It is uncertain whether isometric exercise training reduces vascular access complications (2 studies, 110 participants: RR 2.54, 95% CI 0.38 to 17.08; I² = 47%; very low certainty evidence). It is uncertain whether high volume isotonic exercise training improves venous diameter (2 studies, 93 participants: MD 0.19 mm, 95% CI -0.75 to 1.13; I² = 34%; very low certainty evidence) or blood flow in the inflow artery (1 study, 15 participants: MD -287.70 mL/min, 95% CI -625.99 to 60.59; very low certainty evidence) compared to low volume isotonic exercise training. None of the included studies reported time to mature, dialysis efficacy indicator, vascular access function, or adverse events.

AUTHORS' CONCLUSIONS

Our findings suggest that the current research evidence examining upper limb exercise programs is of low quality, attributable to variability in the type of interventions used and the overall low number of studies and participants.

Impact of a trained vascular access coordinator on a vascular access program in India

BACKGROUND

Native AV fistulas are the ideal access for hemodialysis but require monitoring and multiple interventions in some patients to keep them functioning. The aim of the study was to assess the impact of the appointment of a trained vascular access coordinator (VAC) for fistula monitoring, on the evolution of the vascular access program at our institute.

METHOD

Data was retrieved from the departmental database for the baseline year 2014 and compared with the data from 2018. Initial review showed that appointment of the VAC in 2015 resulted in a steady increase in the number of AV fistula interventions over 2 years to a plateau in 2018 which was chosen as the comparison year. The number of AVF's created, number of salvage procedures performed, and follow-up data were compared. Other parameters like number of operation theatre hours, surgeons, and nursing staff remained constant during this period.

RESULT

Total numbers of AVFs increased from 511 to 713 (39.3%). The number of follow-up visits to surgeons reduced from an average of 4-0.25 visits per patient during this period. Follow up Doppler examinations increased from 761 to 1296 (70%) indicating improved follow up. The salvage procedures increased from 44 to 161 (272%) with early detection of fistula dysfunction. Primary and secondary patency rates of 86% and 92% at 3 months could be achieved whereas limited follow-up data was available for 2014.

CONCLUSION

Appointment of trained VAC increased the number of vascular access procedures, improved follow-up care, and led to early detection and intervention for access dysfunction while reducing the workload of surgeons.

Exercise effectiveness of arteriovenous fistula maturation in chronic renal patients: A systematic review with meta-analysis

Aims:

The purpose of this research is to evaluate the effectiveness of upper limb exercises to improve arteriovenous fistula maturation in patients with chronic kidney disease.

Methods:

A bibliographic search was carried out from February to August 2015 in the following databases: PUBMED, CINAHL, Web of Science, SCOPUS, LILACS, SCIELO and CENTRAL.

Results:

Three studies were included, involving 134 participants (total). According to the total effect estimation, a mean difference of 0.36 (-0.95–1.67) was found for vein diameter, meanwhile a mean difference of 107.87 (-3.90–219.64) was found for blood flow.

Conclusion:

It was not possible to determine the effect size of the treatment due to a high bias risk of all included studies. Given this, the available evidence is still insufficient to support the prescription of upper limb exercises in order to improve arteriovenous fistula maturation. Therefore, randomised and controlled clinical trials monitored by methodological rigour should be developed in order to verify if the AVF maturation process can be evidenced through exercise.