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INTRODUCTION: It is assumed that identification and correction of asymptomatic stenoses in the vascular access circuit will prevent thrombosis that would require urgent intervention to continue hemodialysis treatment. However, the evidence base for this assumption is limited. Recent international clinical practice guidelines reach different conclusions on the use of surveillance for vascular access flow dysfunction and recommend further research to inform clinical practice. METHODS: The FLOW trial is a double-blind, multicenter, randomized controlled trial with a 1:1 individual participant treatment allocation ratio over two study arms. In the intervention group, only symptomatic vascular access stenoses detected by clinical monitoring are treated, whereas in the comparison group asymptomatic stenoses detected by surveillance using monthly dilution flow measurements are treated as well. Hemodialysis patients with a functional arteriovenous vascular access are enrolled. The primary outcome is the access-related intervention rate that will be analyzed using a general linear model with Poisson distribution. Secondary outcomes include patient satisfaction, access-related serious adverse events, and quality of the surveillance process. A cost effectiveness analysis and budget impact analysis will also be conducted. The study requires 828 patient-years of follow-up in 417 participants to detect a difference of 0.25 access-related interventions per year between study groups. DISCUSSION: As one of the largest randomized controlled trials assessing the clinical impact of vascular access surveillance using a strong double-blinded study design, we believe the FLOW trial will provide much-needed evidence to improve vascular access care for hemodialysis patients.
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OBJECTIVE: Deep venous obstruction (DVO) is a great burden on the healthcare system and patients' quality of life (QoL). Case series show stenting is safe and effective, however most studies lack control groups and QoL changes have not been compared with conventional treatment. The aim was to assess the difference in QoL changes from baseline to 12 months between stent and conventionally treated patients with DVO. METHODS: Subjects > 18 years old with DVO due to post-thrombotic (PTS) or non-thrombotic iliac vein lesions (NIVLs) in a tertiary hospital were prospectively randomised to best medical therapy (BMT) or stent placement with BMT in a ratio 2:1, stratified for PTS or NIVL. The primary outcome was the between group difference in VEINES-QoL scores change from baseline to 12 months after treatment. Secondary outcomes included the difference in score changes for EuroQoL 5-Dimension 5 Level (EQ-5D-5L), Pain Disability Index (PDI), Venous Clinical Severity Score (VCSS), and the Villalta score. RESULTS: After three years, the inclusion rate dropped to almost zero, therefore the study had to be stopped. Sixty-three patients were randomised to either the stent (n = 42) or control group (n = 21). Overall, 50 patients had available data for primary outcome analysis. The adjusted mean difference between 12 month scores for VEINES-QoL and VEINES-Sym was 8.07 (95% CI 3.04 - 13.09) and 5.99 (95% CI 0.75 - 11.24) (p = .026), respectively, in favour of the stent group. The differences were significant, but a pre-defined meaningful 14 point improvement in QoL was not reached. The mean difference between 12 month scores for VCSS was -2.93 (95% CI -5.71 - 0.16, p = .040), -11.83 (95% CI -20.81 - 2.86, p = .011) for PDI, 0.015 (95% CI -0.12 - 0.15, p = .82) for the EQ-5D index, and -2.99 (95% CI -7.28 - 1.30, p = .17) for the Villalta score. CONCLUSION: Symptomatic patients with DVO who received dedicated venous stents had significantly higher VEINES-QoL/Sym scores at 12 months compared with the control group, but the between group difference was lower than the pre-specified clinically relevant QoL difference of at least 14 points. STUDY REGISTRATION NUMBER: NCT03026049.
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OBJECTIVE: A significant proportion of patients with abdominal and thoracic aortic aneurysms (AA) do not proceed to intervention after reaching treatment threshold diameter due to a combination of poor cardiovascular reserve, frailty, and aortic morphology. This patient cohort has a high mortality; however, until this study, there exist no studies on the end-of-life care conservatively managed patients receive. METHODS: This is a retrospective multicenter cohort study of 220 conservatively managed patients with AA referred to Leeds Vascular Institute (UK) and Maastricht University Medical Centre (the Netherlands) for intervention between 2017 and 2021. Demographic details, mortality, cause of death, advance care planning and palliative care outcomes were analysed to examine predictors of palliative care referral and efficacy of palliative care consultation. RESULTS: A total of 1506 patients with AA were seen over this time period, giving a nonintervention rate of 15%. There was a 3-year mortality rate of 55%, a median survival of 364 days, and rupture was the reported cause of death in 18% of the decedents. Median follow-up was 34 months. Only 8% of all patients and 16% of decedents received a palliative care consultation, which took place a median of 3.5 days before death. Patients >81 years of age were more likely to have advance care planning. Only 5% and 23% of conservatively managed patients had documentation of preferred place of death and care priorities respectively. Patients with a palliative care consultation were more likely to have these services in place. CONCLUSIONS: Only a small proportion of conservatively treated patients had advance care planning and this was far below international guidelines on end-of-life care for adults, which recommends it for each of these patients. Pathways and guidance should be implemented to ensure patients not offered AA intervention receive end-of-life care and advance care planning.
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Advance Care Planning , Aortic Aneurysm , Terminal Care , Adult , Humans , Outpatients , Cohort Studies , Palliative CareABSTRACT
Background and objectives: Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) cannulas have major repercussions on vascular hemodynamics that can potentially lead to limb ischemia. Duplex ultrasound enables the non-invasive analysis of vascular hemodynamics. This study aims to describe the duplex parameters of the femoral vessels during V-A ECMO support, investigate differences between cannulated and non-cannulated vessels, and analyze the variations in the case of limb ischemia and intra-aortic balloon pumps (IABPs). Methods: Nineteen adults (≥18 years), supported with femoro-femoral V-A ECMO, underwent a duplex analysis of the superficial femoral arteries (SFAs) and veins (FVs). Measured parameters included flow velocities, waveforms, and vessel diameters. Results: 89% of patients had a distal perfusion cannula during duplex analysis and 21% of patients developed limb ischemia. The mean peak systolic flow velocity (PSV) and end-diastolic flow velocity (EDV) of the SFAs on the cannulated side were, respectively, 42.4 and 21.4 cm/s. The SFAs on the non-cannulated side showed a mean PSV and EDV of 87.4 and 19.6 cm/s. All SFAs on the cannulated side had monophasic waveforms, whereas 63% of the SFAs on the non-cannulated side had a multiphasic waveform. Continuous/decreased waveforms were seen in 79% of the FVs on the cannulated side and 61% of the waveforms of the contralateral veins were respirophasic. The mean diameter of the FVs on the cannulated side, in patients who developed limb ischemia, was larger compared to the FVs on the non-cannulated side with a ratio of 1.41 ± 0.12. The group without limb ischemia had a smaller ratio of 1.03 ± 0.25. Conclusions: Femoral cannulas influence flow velocities in the cannulated vessels during V-A ECMO and major waveforms alternations can be seen in all SFAs on the cannulated side and most FVs on the cannulated side. Our data suggest possible venous stasis in the FV on the cannulated side, especially in patients suffering from limb ischemia.
