Results of the endovascular treatment system for occluded native arteriovenous fistula.

BACKGROUND: Arteriovenous fistula is the definitive vascular access for patients on long-term haemodialysis. The aim of this study is to present the techniques and results of the Endovascular Treatment System that we have developed for managing the occluded native arteriovenous fistula. METHODS: The current study is a retrospective chart review on all patients who presented with an occluded native arteriovenous fistula and underwent attempted recanalization between 1 January 2005 and 31 December 2014. RESULTS: A total of 130 patients were included in the study. Post-intervention primary access patency was 83.8% at 6 months, 78.7% at 12 months, 64.6% at 2 years and 59.6% at 3 years. Post-intervention assisted access patency in fistulas-in-use was 86.5% at 6 months, 81% at 12 months, 66.8% at 2 years and 61.2% at 3 years. Post-intervention secondary patency for all cases was 84.7% at 6 months, 80.2% at 12 months, 66.1% at 2 years and 62% at 3 years. Post-intervention secondary patency in fistula-in-use was 91.1% at 6 months, 90% at 12 months, 85% at 2 years and 74.6% at 3 years. Access survival nor patency differed significantly when incisional thrombectomy was compared to angioplasty with or without stenting with access survival of 91.2% and 92.5% at 12 months and access patency of 82.9% and 89.7% at 12 months (P = 0.834 and P = 0.898, respectively). CONCLUSIONS: In autologous arteriovenous thrombosed fistulae, the use of endovascular techniques to revive the access is a viable and safe technique to employ in most cases.

Multicentre, randomised, blinded, control trial of drug-eluting balloon vs Sham in recurrent native dialysis fistula stenoses.

BACKGROUND: Endovascular treatment of autogenous arteriovenous haemodialysis fistula stenosis has high reintervention rates. We investigate the effect of drug-eluting balloons in the treatment of recurrent haemodialysis fistula stenosis. METHODS: This is a randomised, controlled, investigator-initiated and run, prospective, blinded, multicentre trial. Patients with recurrent autogenous arteriovenous haemodialysis fistula stenosis received standard endovascular treatment plus drug-eluting balloon or standard endovascular treatment plus uncoated balloon (Sham). Primary endpoint was late lumen loss in trial area on ultrasound at 6 weeks, 3, 6 and 12 months. Secondary endpoints were freedom from reintervention to the Index Trial Area and decline in fistula flow (Qa). Interim analysis was performed at 6 months (unblinded due to timeliness). RESULTS: Patients with 132 recurrent stenoses (48% in bare Nitinol stents) were randomised with 70 receiving drug-eluting balloon and 62 Sham. At 6 months, decline in late lumen loss was 0.23 ± 0.03 mm/month for Sham and 0.045 ± 0.03 mm/month for drug-eluting balloon arm, a significant difference (0.18 mm, p = 0.0002). At 12 months, this difference persisted at 0.12 mm (p = 0.0003). At 6 months, significant difference in late lumen loss for instent restenoses (p = 0.0004) was observed, with non-significant difference for unstented restenoses (p = 0.065). Mean time for freedom from reintervention was 10.14 months for Sham versus 42.39 months for drug-eluting balloon (p = 0.001). The same was shown for instent (p = 0.014) and unstented (p = 0.029) restenoses. Qa decline rate at 6 months was 36.89 mL/min/month (Sham) and 0.41 mL/min (drug-eluting balloon). The difference was significant (36.48 mL/min; p = 0.02) and persisted to 12 months (p = 0.44). CONCLUSION: Paclitaxel drug-eluting balloon significantly delays restenosis after angioplasty for recurrent autogenous arteriovenous haemodialysis fistula stenosis, persisting to 12 months. Drug-eluting balloon significantly increases freedom from reintervention at 12 months with these effects true in stented and unstented fistulas.

Human classical monocytes display unbalanced M1/M2 phenotype with increased atherosclerotic risk and presence of disease.

BACKGROUND: Specific monocyte and macrophage subsets have been implicated in atherosclerosis, with intermediate monocytes proportionally elevated in cardiovascular disease and M1 macrophages abundant in unstable atherosclerotic plaques. While several studies have shown altered proportions of these subsets in atherosclerosis, studies examining functional and phenotypic subset alterations remain scarce. METHODS: We used whole blood flow cytometry to investigate the expression of M1 (CD86) and M2 (CD163) markers on monocyte subsets of atherosclerotic patients and controls. RESULTS: Atherosclerotic patients had a more inflammatory monocyte profile than controls, indicated by increased intermediate subset proportions, a higher classical monocyte CD86/CD163 ratio, and elevated serum M1-related chemokines. A more inflammatory profile appeared to correlate with atherosclerotic risk, as in controls classical monocyte CD86/CD163 ratio was negatively correlated with HDL and apolipoprotein A1, and positively correlated with interleukin-1ß. CONCLUSIONS: We conclude that monocyte subsets show functional and phenotypic changes in cardiovascular disease and such changes are likely to contribute to atherosclerotic progression.