Short Term Success of Treatments to Salvage Thrombosed or Failing Synthetic Arteriovenous Grafts in End Stage Renal Disease: A Systematic Review and Network Meta-Analysis of Randomised Controlled Trials

Interventions for thrombosed haemodialysis arteriovenous fistulas and grafts

BACKGROUND

Patients who present with problems with definitive dialysis access (arteriovenous fistula (AVF) or arteriovenous graft (AVG)) become catheter dependent (temporary access), a condition that often carries a higher risk of infections, central venous occlusions and recurrent hospitalisations. For AVG, primary patency rates are reported to be 30% to 90% in patients undergoing thrombectomy or thrombolysis. According to the National Kidney Foundation-Kidney Disease Outcomes Quality Initiative (NKF-KDOQI) guidelines, surgery is preferred when the cause of the thrombosis is a stenosis at the site of the anastomosis in thrombosed AVF. The European Best Practice Guidelines (EBPG) reported that thrombosed AVF may be preferably treated with endovascular techniques, but when the cause of thrombosis is in the anastomosis, surgery provides better results with re-anastomosis. Therefore, there is a need to carry out a systematic review to determine the effectiveness and safety of the intervention for thrombosed fistulae.

OBJECTIVES

This review aims to establish the efficacy and safety of interventions for failed AVF and AVG in patients receiving haemodialysis (HD).

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 28 January 2024 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, EMBASE, conference proceedings, the International Clinical Trials Registry Portal (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

The review included randomised controlled trials (RCTs) and quasi-RCTs in people undergoing HD treatment using AVF or AVG presenting with clinical or haemodynamic evidence of thrombosis. Patients had to have used an AVF or AVG at least once.

DATA COLLECTION AND ANALYSIS

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. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

Our search strategy identified 14 eligible studies (1176 randomised participants) for inclusion in this review. We included three types of interventions for the treatment of thrombosed AVF and AVG: (1) types of thrombectomy, (2) types of thrombolysis and (3) surgical procedures. Most of the included studies had a high risk of bias due to a poor study design, a low number of patients and industry involvement. Overall, there was insufficient evidence to suggest that a specific intervention was better than another for the outcomes of failure, primary patency at 30 days, technical success and adverse events (both major and minor). Primary patency at 30 days may improve with surgical compared to mechanical thrombectomy (3 studies, 404 participants: RR 1.36, 95% CI 1.07 to 1.67); however, the evidence is very uncertain. Death, access dysfunction, successful dialysis, and SONG (Standards Outcomes in Nephrology) outcomes were rarely reported. The current review is limited by the small number of available studies with a limited number of patients enrolled. Most of the studies included in this review have a high risk of bias and a low or very low certainty of evidence. Further research is required to define the most effective and clinically appropriate technique for access dysfunction.

AUTHORS' CONCLUSIONS

It remains unclear whether any intervention therapy affects the patency at 30 days or failure in any thrombosed HD AV access (very low certainty of evidence). Future research will very likely change the evidence base. Based on the importance of HD access to these patients, future studies of these interventions among people receiving HD should be a priority.

Plain versus paclitaxel-coated balloon angioplasty in arteriovenous fistula and graft stenosis: An umbrella review

An umbrella review was performed to synthesize the evidence from systematic reviews/meta-analyses of clinical trials investigating the efficacy and safety of paclitaxel-coated balloons (PCB) vs. conventional balloon angioplasty in arteriovenous fistulas (AVFs) and grafts stenosis.Medline (via PubMed) and SCOPUS databases were searched up to July 15th 2020. All meta-analyses that enrolled randomized controlled trials (RCTs) comparing PCB with plain balloons in AVFs and grafts were included. Re-analysis of original data was performed assessing predictive intervals (PI). Quality of the included meta-analyses was assessed using AMSTAR score. Eight meta-analyses were included and four clinical outcomes [target lesion primary patency (TLPP), circuit primary patency, mortality, complication rate] derived from 14 RCTs, were analyzed. There were no significant differences in the TLPP in meta-analyses providing data purely from autologous AVFs. Significant benefits regarding TLPP and circuit primary patency at 3, 6, and 12-months in favor of PCB were reported in four meta-analyses mixing AVFs and grafts; however when PI were assessed, in all but one meta-analysis these included the null value, indicating no significant benefit. In only one meta-analysis significant difference of TLPP at 12-months in favor of PCB was noticed. (Odds Ratio 0.0009 PI: 0.28-0.85) No mortality difference was noticed in four meta-analyses providing data up to 24 months. In conclusion this overview revealed a modest benefit of using PCB angioplasty compared to plain angioplasty in AVFs and graft stenosis. No increased mortality was noticed in the PCB group.