View clinical trials related to Dialysis Access Malfunction.
Filter by:To determine if cutting balloon angioplasty combined with DEB angioplasty provides a higher primary patency after treatment of recurrent stenoses compared with cutting balloon angioplasty or angioplasty using DEB alone in the venous outflow AVFs. For cutting balloon angioplasty in venous stenosis, the primary patency after 12 months is 55-60% (9,16) and in recurrent stenoses up to 48%(10). We hypothesise that DEB angioplasty after cutting balloon angioplasty leads to improved primary patency at 12 months.
Recent studies of paclitaxel DCB in the treatment of stenosis at dialysis vascular access have shown promising results. Paclitaxel, an anti-proliferation drug, is released during balloon inflation and potentially improve primary patency by slowing down NIH effect. However, meta-analysis have suggested that the use of paclitaxel in lower limbs have increased risk of death in patients. The effect of paclitaxel DCB on dialysis access however remains unknown. Hence, we aim to set up a database to track long-term treatment outcomes of patients treated with Paclitaxel DCB at SGH for their stenosed dialysis access
VAVASC trial is an observational multicentre study. The aim of this trial is to validate AVAS (arteriovenous vascular access stage) classification. The classification is used for determining which type of access is the most suitable for the patient on the basis of the patient´s vascular anatomy The methodology of this trial is to apply AVAS classification on patients who are indicated for creation of vascular access for hemodialysis. Data on these patients (vascular anatomy status, AVAS type, and predicted type of arterio venous access, demographic data etc.) will be than statistically analysed. Patients will then undergo creation of the selected arteriovenous access. They will be observed in terms of the access functionality. The follow up will be 1 to 3 years. The second aim of this study is to evaluate the relationship between AVAS classification and uninterrupted use of the created arterio venous access.
For patients with End Stage Renal Failure (ESRF), the surgical creation of an Autogenous Arteriovenous Fistula (AVF) or Autogenous Arteriovenous Graft (AVG) is the recognised standard for providing vascular access. A functioning dialysis vascular access is essential to facilitate hemodialysis (HD) treatment. Advantages include improved hemodialysis initiation time, improved dialysis quality, better maintenance of accesses and generally, better outcomes in patients. Unfortunately almost 50% of AVF and AVG fail after a median lifetime of 3 to 7 years and 12 to 18 months respectively. Vascular access dysfunction is a major cause of morbidity and hospitalisation for ESRF patients, costing the healthcare system USD 18 million globally. Venous stenosis and scarring are caused by trauma from surgical access creation when the circuit comes arterialized and from repeated percutaneous punctures from subsequent hemodialysis. This study is performed to evaluate Sirolimus-coated balloon efficacy and safety using MagicTouch™ Drug coated balloon catheter (Concept Medical Inc, Tampa, FL, US) on AVF patency with de novo and recurrent stenosis.
This is a multicenter, prospective study investigating a new concept of intra-procedural percutaneous duplex ultrasound (DUS) volume flow-guided balloon angioplasty for the quantification and optimization of endovascular treatment outcomes of dysfunctional autologous arteriovenous fistulae (AVF).
Hemodialysis vascular access dysfunction continues to be a major source of morbidity and mortality in patients with ESRD. Thrombosis is the most common cause of secondary vascular access failure Although intimal hyperplasia at the outflow vein is the most common cause of thrombosis, 20-40% of thrombosis may develop secondary without underlying anatomic abnormalities. Low-flow states secondary to low BP have been proposed to precipitate access thrombosis. In previous studies, lower pre- and post- dialysis SBP are associated with a higher rate of access thrombosis. Nonetheless, high blood pressure is also a well-known risk factor for arteriosclerosis, intimal hyperplasia, and thrombotic vascular events. In dialysis patients, the relation between blood pressure and thrombosis seems to be more complex, and few studies have delineated the effect of blood pressure in a systematic manner. In addition to the static component of blood pressure, blood pressure variability (BPV) is increasingly accepted as a novel risk factors for vascular disease. BPV is categorized as either long or short term. In dialysis patients, long-term BPV is typically defined on the basis of BP measurements taken at the start of hemodialysis (inter-dialysis BPV); short-term BPV is usually considered in terms of variability during hemodialysis (intra-dialysis BPV). BP variability is increased in ESRD patients and is associated with adverse outcomes. To the best of our knowledge, only one study by Cheung et al focused on intra-dialytic BPV, which found intradialytic hypotension to be a risk factor for access thrombosis. Nonetheless, access thrombotic events rarely occur during the dialysis session. It remained unclear that if inter-dialysis BPV is a more relevant factor for access thrombosis. Answer to this question is of clinical significance because the optimal BP target after PTA remained unknown. In this study, we aimed to investigate the effect of BP variability on the outcomes of hemodialysis vascular access, major cardiovascular events in maintenance hemodialysis patients. We also aimed to evaluate the determinants of BPV in hemodialysis patients, including medication, frailty, fluid status and autonomic function. The impact of autonomic function and frailty on the outcomes of vascular access and cardiovascular events will be evaluated as well.
The most common problem with haemodialysis arteriovenous fistulas (AVF) and arterio-venous grafts (AVG) is stenosis, which can lead to inadequate dialysis, and eventual access thrombosis. Conventional plain old balloon angioplasty (CBA) is associated with high recurrence rates of stenosis and repeated interventions. The advent of successful drug-eluting technology in the treatment of the coronary vascular bed and subsequent positive accumulating evidence in the peripheral arterial circulation has prompted the use of drug coated balloons (DCB) in the access fistula circuit for venous stenosis and in-stent restenosis. Recent studies suggest that DCBs may significantly reduce re-intervention rates on native and recurrent lesions. The restenosis process is in part or in whole the result of neo-intimal hyperplasia (NIH) and NIH is considered the main culprit in access circuit target lesion stenosis. NIH is the blood vessel's healing response to the barotrauma from the angioplasty process. A critical component of NIH is the cellular proliferative stage with mononuclear leucocytes identified as the primary inflammatory cell type involved. The rationale for drug elution is to block the NIH response with an anti-metabolite such as paclitaxel. It is important to emphasize that the role of drug elution in the treatment of vascular stenosis is not to obtain a good haemodynamic and luminal result but to preserve a good result obtained during POBA from later restenosis due to NIH and minimise reinterventions and readmissions to hospital for what is a frail population of patients. A meta-analysis performed by Khawaja et al. seemed to suggest that DCBs conferred some benefit in terms of improving target lesion primary patency (TLPP) in AVFs. An updated meta-analysis performed by our own institution recently reinforced that DCB appears to be a better and safe alternative to CBA in treating patients with stenosis within all haemodialysis circuits (fistulas and grafts) based on 6- and 12-months primary patency and increased intervention free period 5. However, this was not reflected in the largest RCT to date of DCB vs CBA in AVF with no superior target lesion patency demonstrated at six months and one and two years follow-up. Another recent meta-analysis found paclitaxel-coated balloons (PCB) showed no statistically significant improvement over conventional balloons in decreasing fistula stenosis in randomized controlled trials but were significant for cohort studies. Hence this shows the heterogeneity of the available data in the literature and the result is dependent on what studies you include in the review. Another reason why the outcome data is variable is that the high-speed blood flow in dialysis access circuits washes a large amount of the paclitaxel away from the target lesion soon after application. A measurement in swine showed that only 20%-30% of paclitaxel was taken up into the coronary artery wall in vivo 15-25minutes after PCB application. Furthermore, recent attention has been drawn to a possible increase in late mortality signal and lower amputation free survival in patients receiving DCB treatment with paclitaxel for peripheral arterial disease, although this suggestion has not been demonstrated in the data of DCB within the fistula circuit either at 1 or 2 years. In light of these concerns, attention has turned away recently from paclitaxel-based technologies to sirolimus coated platforms. Sirolimus, like paclitaxel, is a potent antiproliferative agent, which has been found to prevent restenosis in the coronary bed and more recently in the peripheral vasculature but to date has not been studied in AVF circuits The aims of the study is to determine the safety and efficacy of the MedAlliance SELUTION SLR 018™ DEB in the treatment of failing AV fistula due to conduit stenosis in patients undergoing renal dialysis.
This is a pilot study investigating a new concept of intra-procedural percutaneous duplex ultrasound (DUS) volume flow-guided balloon angioplasty for the quantification and optimization of endovascular treatment outcomes of dysfunctional autologous arteriovenous fistulae (AVF).
The most common problem with haemodialysis arteriovenous fistulas (AVF) and arterio-venous grafts (AVG) is stenosis, which can lead to inadequate dialysis, and eventual access thrombosis. Conventional plain old balloon angioplasty is associate with high recurrence rates of stenosis and repeated interventions. The advent of successful drug-eluting technology in the treatment of the coronary vascular bed and subsequent positive accumulating evidence in the peripheral arterial circulation has prompted the use of drug coated balloons (DCB) in the access fistula circuit for venous stenosis and in-stent restenosis. Recent studies suggest that DCBs may significantly reduce re-intervention rates on native and recurrent lesions. The restenosis process is in part or in whole the result of neo-intimal hyperplasia (NIH) and NIH is considered the main culprit in access circuit target lesion stenosis. NIH is the blood vessel's healing response to the barotrauma from the angioplasty process. A critical component of NIH is the cellular proliferative stage with mononuclear leucocytes identified as the primary inflammatory cell type involved. The rationale for drug elution is to block the NIH response with an anti-metabolite such as paclitaxel. It is important to emphasize that the role of drug elution in the treatment of vascular stenosis is not to obtain a good haemodynamic and luminal result but to preserve a good result obtained during POBA from later restenosis due to NIH and minimise reinterventions and readmissions to hospital for what is a frail population of patients. A meta-analysis performed by Khawaja et al. seemed to suggest that DCBs conferred some benefit in terms of improving target lesion primary patency (TLPP) in AVFs. An updated meta-analysis performed by our own institution recently showed that DCB appears to be a better and safe alternative to conventional balloon angioplasty (CBA) in treating patients with HD stenosis based on 6- and 12-months primary patency and increased intervention free period. The Passeo-18 Lux (Biotronik Asia Pacific Pte Ltd (Singapore)) drug-coated balloon (DCB) is packaged with a low dose of paclitaxel. Recent studies have shown that low dose coating of paclitaxel with this DCB is useful for preventing restenosis, decrease lumen loss and target lesion revascularization in the peripheral vasculature6 but has not been tested in the dialysis access circuit.
The results of this study will serve as a starting point for future trials concentrating on the effectiveness and clinical outcomes of the procedures performed in an office based angiosuite. Additionally, other studies could compare clinical outcomes between procedures performed in an office based angiosuite and other settings.