Arteriovenous Fistula Dysfunction Research Articles

Role of renal vascular coordinator on access flow dysfunction: A quality improvement initiative on improving patency rate.

A renal vascular coordinator (RVC) is a single point-of-contact allied health professional in the early detection and timely intervention of flow dysfunction. In Khoo Teck Puat Hospital (KTPH), RVC performs access ultrasonography assessment and assists in reviewing direct referrals about dysfunctional arteriovenous fistula (AVF)/arteriovenous graft (AVG) from community dialysis centres and plans for appointments with interventional nephrologists and vascular surgeons. We conducted a prospective study from April 2020 to December 2022 to evaluate the appointment-to-intervention time (AIT) and patency rate (PR) of vascular access interventions. Secondary outcome was the percentage of vascular access loss. Ninety-three patients were referred to the RVC and were offered thrombectomy or angioplasty. Twenty-seven patients were excluded from the analysis (did not require intervention (9), admitted without RVC assessment (13), defaulted (4), or bypassed an RVC appointment to their first intervention (1)). The median time from referral to their first RVC visit was 4 (3-6) days. The median AIT for the RVC group was 6 (3-11) days (21.5% within 48 h). The median AIT for the non-RVC group was 6 (2.3-12.8) days (25.5% within 48 h, p = 1.0). The 6-month and 12-month post-intervention PR was 71% and 61.3%, respectively. Fifty-one of the remaining ninety-three patients had previous procedures done to their AVF before April 2020 without RVC involvement. The 6-month and 12-month post-intervention PR was 51% (p < 0.016) and 15.7% (p < 0.00001), respectively. The percentage of vascular access loss was similar in both RVC and non-RVC groups (4.3% vs 2%, p = 0.44). With the addition of RVC, vascular access outcome is improved with longer PR for up to 12 months, with no difference in AIT and number of vascular access losses.

Factors associated with early and late losses of primary patency following drug-coated balloon for dysfunctional arteriovenous fistula.

This study aimed to evaluate the effectiveness of a drug-coated balloon (DCB) for the treatment of dysfunctional arteriovenous fistulas (AVFs) and to identify the risk factors associated with early and late losses of primary patency following DCB in real-world practice. This multicenter, retrospective study included 407 patients (72 ± 11 years, 64.1% males) with dysfunctional AVFs (juxta-anastomotic lesion location in 58.7% of cases, mean size 1.2 mm, mean length 54 mm) who underwent DCB for the first time for the treatment of dysfunctional AVF. The primary outcome measure was the loss of primary patency after DCB. The secondary outcome measures were the factors associated with early (<90 days) and late (⩾90 days) losses of primary patency after DCB. The primary patency rates 6 and 12 months after DCB were 72.5% ± 2.3% and 40.1% ± 2.7%, respectively. The factors associated with the early loss of primary patency were de novo lesions (adjusted hazard ratio [HR], 7.91; [95% confidence interval (CI), 1.90-32.97]; p = 0.005), endovascular treatment (EVT) history within the previous 90 days (adjusted HR, 9.29; [95% CI, 3.09-27.92]; p < 0.001) and juxta-anastomotic stenosis (adjusted HR, 0.30; [95% CI, 0.13-0.70]; p = 0.005). The factors associated with a late loss of primary patency included EVT history within the previous 90 days (adjusted HR, 2.52; [95% CI, 1.89-3.38]; p < 0.001) and pre-dilation balloon size (adjusted HR, 1.99; [95% CI, 1.50-2.64]; p < 0.001). DCB is an effective device to prolong the patency of dysfunctional AVFs in most cases. De novo lesions and their locations were associated with an early loss of primary patency, whereas the vessel preparation balloon size was associated with a late loss of primary patency. EVT history within the previous 90 days was associated with early and late losses of primary patency.

Cephalic to jugular vein bypass surgery of subclavian vein stenosis for arteriovenous fistula salvage in maintenance hemodialysis patients.

Ipsilateral subclavian vein stenosis in a well-functioning upper extremity arteriovenous fistula (AVF) is a significant factor contributing to AVF failure and sometimes swelling of ipsilateral upper extremity. Graft bypass surgery can alleviate outflow tract stenosis in upper extremity AVF, restore function, and efficiently relieve arm swelling. The present study aimed to evaluate patency and postoperative complications after cephalic to jugular graft bypass surgery in patients with upper extremity AVF failure or upper extremity swelling on the same side of the AVF resulting from ipsilateral subclavian vein stenosis. Five patients with upper extremity AVF and ipsilateral subclavian vein stenosis undergoing maintenance hemodialysis were included. Three patients had AVF dysfunction, while two experienced swelling of the arm due to high venous pressure in the AVF. The surgical procedure involved creating a subcutaneous tunnel in the shoulder to connect a 6 mm polytetrafluorethylene (PTFE) graft, from either near the fistula site (n = 3) or at the mid-upper arm cephalic vein (n = 2), to the jugular vein. Graft bypass surgery was successful, and all patients were able to resume hemodialysis postoperatively. Upper extremity edema improved, without any postoperative wound infections, non-healing wounds, steal syndrome, or high-flow AVF leading to heart failure as a complication. Five to 19 months after surgery, the bypass grafts exhibited a primary patency rate of 100%, and vascular access fulfilled the requirements for hemodialysis. Cephalic to jugular vein bypass surgery for upper extremity AVF with ipsilateral subclavian vein stenosis effectively preserved function of the original fistula, and was associated with few postoperative complications.

Mineralocorticoid receptor antagonism attenuates arteriovenous fistula stenosis by modulating the phenotype of vascular smooth muscle cells.

Fistula stenosis is a primary contributor to arteriovenous fistula (AVF) failure in maintenance hemodialysis patients. Emerging data indicated excessive fibrotic remodeling was the primarily contributor to fistula stenosis during AVF remodeling. The mineralocorticoid receptor (MR) has been implicated in vascular remodeling across various cardiovascular pathologies. However, its role in AVF remodeling, particularly concerning fibrotic remodeling, remains elusive. MR expression and the phenotypes of vascular smooth muscle cells (VSMCs) were assessed in dysfunctional AVF. The effects of MR on VSMC phenotypic switching were examined in vitro, and the protective effects of MR antagonists on AVF outcome were evaluated in a rat AVF model. Dysfunctional fistula exhibited significant medial fibrosis and extracellular matrix deposition, alongside markedly increased MR activity. In the dysfunctional fistula vessels, VSMC displayed reduced expression of the contractile marker SMMHC and featured characteristic of a synthetic phenotype, including increased osteopontin expression and heightened proliferation. In vitro studies with cultured VSMC revealed that MR overactivity induced by aldosterone led to phenotypic switching from contractile to synthetic state, concomitant with EGFR-ERK1/2 pathway overactivation. These effects were largely abolished by the MR antagonist fineronone. Knockdown of EGFR expression abrogated ERK1/2 phosphorylation and inhibited the VSMC phenotypic switching. Conversely, ectopic overexpression of EGFR in VSMC diminished the protective effect of finerenone. In rat AVF models, pharmacologic targeting of MR with finerenone significantly improved AVF outcomes, characterized by increased luminal diameters and flow volume, reduced medial fibrosis, and inhibited VSMC phenotypic switching. These beneficial outcomes were likely attributable to a restrained activity of EGFR-ERK1/2 pathway in VSMC and elevated NO production in endothelial cells. Our study demonstrated that therapeutic targeting of MR may improve AVF outcome by modulating VSMC phenotypic switching. These findings offer promising avenues for further clinical investigations aimed at optimizing AVF outcomes in the hemodialysis population.

Factors associated with dysfunction of autogenous arteriovenous fistula in patients with secondary hyperparathyroidism after parathyroidectomy

Background Secondary hyperparathyroidism (SHPT) is a prevalent chronic complication in patients undergoing hemodialysis. Parathyroidectomy (PTX) is crucial for reducing mortality and improving the prognosis in the treatment of refractory hyperparathyroidism. However, it is often associated with a number of postoperative complications such as postoperative hypotension, hyperkalemia, and hungry bone syndrome. A previous study demonstrated that low blood pressure influences the patency of autogenous arteriovenous fistulas (AVF). Few studies have examined AVF dysfunction following PTX. This study aimed to identify and describe the risk variables associated with AVF dysfunction after PTX. Methods Cases of AVF dysfunction after PTX between 2015 and 2021 were studied. Four controls were identified for each patient and were matched for sex and age. Biochemical parameters and blood pressure of the patients before and after PTX were recorded. Risk factors for AVF dysfunction after PTX were identified using conditional logistic regression analysis. Results Sixteen patients and 64 controls were included in this study. Baseline demographic and laboratory data were compared. Patients in the AVF dysfunction group had lower levels of postoperative calcium than the controls. After surgery, calcium levels decreased more in patients with AVF dysfunction than in the control group. The decrease in systolic blood pressure (ΔSBP) after PTX was greater in the AVF dysfunction group than that in the control group. For each 1 mmHg increment in ΔSBP, the risk of AVF dysfunction after surgery increased by 11.6% (OR = 1.116, 95% CI, 1.005–1.239, p = .040). The likelihood of developing AVF dysfunction after surgery was twelvefold higher in diabetic patients than in non-diabetic patients (OR = 12.506, 95% CI, 1.113–140.492, p = .041). Among patients with ΔSBP > 5.8 mmHg after PTX, the AVF failure rate was significantly greater in patients with diabetes than in those without diabetes. Patients with a history of AVF failure had a nine-fold higher risk of developing AVF dysfunction (OR = 9.143, 95% CI, 1.151–72.627, p = .036). Serum albumin, hemoglobin, ΔiPTH, and age were not independent predictors of AVF dysfunction. The cutoff value for SBP was 5.8 mmHg, as determined by the Youden index of the receiver operating characteristic curve. Conclusion Decreased systolic blood pressure (ΔSBP) after PTX, diabetes, and AVF failure history were risk factors for AVF dysfunction following PTX in patients with SHPT. Diabetes patients with ΔSBP > 5.8 mmHg were more prone to AVF dysfunction after PTX.

Response to E.M. Zeltyn-Abramov's comment to the article "Left ventricular ejection fraction: association with risk of death and incidence of arteriovenous fistula dysfunction (mid-term results)"

.

Feasibility of an antegrade-retrograde single-sheath inverse technique via vertical puncture in dysfunctional hemodialysis arteriovenous fistula angioplasty

BackgroundStenosis resulting in dysfunctional dialysis access may occur simultaneously on the anastomotic and central venous side. The purpose of this study was to retrospectively evaluate the feasibility of a single sheath inverse technique using the vertical puncture approach to perform bidirectional transvenous percutaneous transluminal angioplasty (PTA) from a single sheath for such dialysis access stenoses.Materials and MethodsTwenty patients (26 cases; 13 males; median age, 74 [range: 50–89] years) who underwent PTA using the sheath inverse technique for dysfunctional arteriovenous fistula stenoses between April 2019 and June 2023 were included. All procedures were performed in an outpatient setting. A 4-cm sheath (4Fr, four cases; 5Fr, 19 cases; 6Fr, three cases) was inserted by vertical puncture through a cutaneous vein in the forearm (20 cases) or upper arm (six cases). After treating one side of the lesion, the sheath was reversed to treat the lesion on the opposite side. The vessel diameter at the sheath insertion site, the success rate of sheath inversion, the number of PTA balloon catheters used, the PTA success rate, adverse events, and primary and secondary patency rates up to one year after PTA were evaluated.ResultsThe median diameter at the sheath indwelling site was 5.2 (range: 3.6–9.5) mm, and sheath inversion was successful in all cases, eliminating the need to place an additional sheath at another site for contralateral stricture treatment. The number of balloon catheters used was one and two in 17 (65%) and eight cases (31%), respectively, and three in one case wherein a drug-coated balloon was used. PTA was successful in all cases and major complications were not observed. However, in one case wherein a sheath had to be placed at the arterial needle puncture site, the skin was hard, leading to difficulty in inversion, and transient venous spasm occurred post-inversion. The primary patency rates at 3, 6 and 12 months after the PTA were 87.5%, 41.7%, and 20.8%, respectively. The secondary patency rates at 6 and 12 months were 100% and 75%, respectively.ConclusionThe single-sheath inverse technique for arteriovenous fistulas was feasible without sheath withdrawal.Graphical

Patency and factors related to patency after percutaneous transluminal angioplasty for inflow arterial stenosis in native arteriovenous fistula dysfunction: a single-center retrospective study

Controversy still exists regarding how much the inflow arterial percutaneous transluminal angioplasty (PTA) contributed to maintaining fistula function for hemodialysis. We aimed to analyze patency and risk factors after inflow arterial PTA. Hemodialysis patients with inflow arterial primary stenosis who were admitted to our institution from January 2017 to December 2022 were examined. One group had arterial-venous fistula with inflow artery stenosis alone (AVF + iAS) and another group had AVF with inflow artery stenosis and any vein stenosis (AVF + iAS + VS). The characteristics of patients, stenotic lesions, and PTA procedures were recorded. Kaplan–Meier analysis was used to compare primary patency, assisted primary patency, and secondary patency in the two groups. Cox proportional hazard analysis was used to identify risk factors associated with patency. We examined 213 patients, 53 in the AVF + iAS group (51 radial arterial stenosis and 2 ulnar arterial stenosis) and 160 in the AVF + iAS + VS group (159 radial arterial stenosis and 1 ulnar arterial stenosis). Kaplan–Meier analysis indicated the AVF + iAS group had better primary patency and assisted primary patency (both P < 0.05), but the groups had similar secondary patency. Cox proportional hazard analysis indicated that none of the analyzed clinical and biochemical indexes had clinically meaningful effects on primary patency, assisted primary patency, or secondary patency in either group. The patency and safety after PTA for inflow arterial stenosis were satisfactory, and none of the examined risk factors had a major clinical impact on patency. We recommend PTA as treatment for inflow stenosis of an AVF.

The impact of depression on platelet activation, cardiocerebral vascular events and arteriovenous fistula dysfunction in patients undergoing haemodialysis

Depression is a common psychiatric disorder among patients undergoing maintenance haemodialysis (MHD). Depression may reportedly contribute to poor prognosis in several ways, including its effects on platelet function. We hypothesised that depression contributes to the occurrence of cardiocerebral vascular events (CCVE) and dysfunction of arteriovenous fistula (DAVF) in patients undergoing MHD through its effects on platelets. In this prospective cohort study, patients undergoing MHD were recruited and divided into depression and non-depression groups according to their Hamilton Depression Scale (HAMD) scores. The 286 enrolled patients had 103 occurrences of depressive symptoms (prevalence = 36.01%). Compared with the non-depression group, depression group had a significantly higher cumulative prevalence of CCVE and DAVF during follow-up. Cox regression analysis indicated that higher HAMD scores and lower plasma platelet distribution width (PDW) were common risk factors for CCVE and DAVF. Furthermore, HAMD scores were significantly negatively correlated with plasma PDW and was the main variable affecting changes in PDW, as indicated by multiple linear regression analysis. Depression may increase the risk of CCVE and DAVF in patients undergoing MHD by activating platelets. Plasma PDW may be a convenient indicator of platelet activation status and may predict the risk of CCVE and DAVF.

Effectiveness of Initial and Repeat Drug-Coated Balloon Angioplasty of Restenotic Arteriovenous Fistulae Compared with That of Plain Angioplasty

PurposeTo evaluate the effect of drug-coated balloon (DCB) with high-dose paclitaxel for the treatment of restenotic dysfunctional arteriovenous fistulae (AVFs). Materials and MethodsIn this single-arm, multicenter, prospective, observational study, 334 patients who underwent DCB angioplasty using IN.PACT AV (Medtronic, Plymouth, Minnesota) for the first time for restenotic lesions of dysfunctional AVFs between April 2021 and March 2022 were registered. Outcomes were compared with the outcomes of plain angioplasty performed previously, leading up to the restenosis. ResultsProcedural success, defined as <30% residual stenosis, was achieved in 96.7% of cases. During a median follow-up of 7.4 months, 179 target lesion reinterventions (TLRs) were observed, and the 6-month freedom from TLR was 73.2% (68.2%–78.2%). When compared with the previous plain angioplasty, the median time to reintervention was significantly longer with DCB (9.1 [8.0–10.6] vs 3.2 [3.0–3.4] months; P < .001). Baseline characteristics that were independently associated with TLR were as follows: months from the last intervention (adjusted hazard ratio, 0.50 [95% confidence interval, 0.40−0.62] per doubling; P < .001), partial lesion coverage by DCB (2.13 [1.10−4.12]; P = .024), and residual stenosis after DCB (2.19 [1.53−3.12] per 15% increase; P < .001) with its time interaction (0.91 [0.86−0.97] per month; P = .003). Of the 179 TLRs, 84 used DCB once again. The median time to reintervention was significantly longer for TLR using DCB (7.1 [6.2–9.7] vs 3.3 [3.1–4.0] months; P < .001). ConclusionsDCB with high-dose paclitaxel is effective at both the initial treatment of restenotic lesions of dysfunctional AVFs and during TLR after DCB use. Partial lesion coverage by DCB and residual stenosis may compromise patency.

Drug-coated balloons versus conventional percutaneous transluminal angioplasty for treatment-naïve dysfunctional arteriovenous fistulas.: A 10-year single center retrospective study.

To compare the primary patency and restenosis rates in treatment naieve dialysis arteriovenous fistulas (AVFs) after drug-coated balloons (DCB) versus plain balloon angioplasty (PTA). This retrospective study included 157 patients who underwent AVF angioplasty for treatment-native AVF stenosis between January 2012 to 2022. The fistulas were Brachiocephalic (75%), Brachiobasilic (17%), and radiocephalic (8%). The index intervention was with either DCB or percutaneous transluminal angioplasty (PTA) with subsequent follow up. Patients with central venous stenosis, thrombosed fistula, fistula stents, AV graft or surgical intervention after the index procedure were excluded. Arteriovenous fistula angioplasty was done in 28 patients using DCB and in 129 patients using PTA. A total of 108 patients presented with a single stenosis, 42 with 2 stenoses, and 7 with 3 stenoses. The location of these stenoses was in the venous outflow (57%), the juxta anastomotic segment (31%), and cephalic arch (12%). The median time to re-intervention for the PTA was 216 days compared to 304 days for the DCB (p=0.079). Primary patency at 6 months was 60.4% for PTA and 75% for DCB (p=0.141) CONCLUSION: Although DCB angioplasty of treatmentnaïve dysfunctional AVF tends to improve the time to intervention and 6-month primary patency compared to PTA, this difference did not reach statistical significance.

Pivotal Role of Duplex Ultrasonography on Arteriovenous Fistula for Hemodialysis Access

The global incidence of end-stage renal disease (ESRD) is rising, amounting to more than 800 million individuals are suffered, in line with the rise of the number of patients undergoing hemodialysis as treatment modalities. Hemodialysis requires vascular access, and the arteriovenous fistula (AVF) access is considered the most ideal vascular access option due to its long-term patency and low complication rate compared to other access options. However, up to one-third of hospital admissions for ESRD patients are caused by AVF dysfunction, which is also one of the main causes of morbidity and mortality in ESRD patients. AVF creation requires careful pre- and post-operative evaluation to ensure the vascular access maturation and patency. While the latest guidelines have not explicitly emphasized the role of vascular mapping and surveillance, routine duplex ultrasonography before and after AVF creation procedures holds great potential advantages to ensure the success of AV access for hemodialysis.

Serial angiography and angioscopy of late lumen enlargement after drug-coated balloon for dysfunctional arteriovenous fistula.

The use of a drug-coated balloon (DCB) to treat dysfunctional arteriovenous fistula (AVF) has shown promising results. After percutaneous coronary intervention with DCB, late lumen enlargement (LLE) often develops in the early follow-up phase, but questions regarding the natural history of changes in lesions after DCB angioplasty have not been clearly elucidated. Here, we reported on a patient in whom angiography and angioscopy were performed immediately and 4 months after DCB angioplasty to treat cephalic vein stenosis of the dysfunctional AVF. Immediately after DCB application, angiography showed good dilatation and blood flow and mild vascular dissection that did not affect blood flow. Angioscopy showed that although the balloon had damaged the intima and the paclitaxel particles had adhered to the vessel wall. Four months after DCB treatment, follow-up angiography and angioscopy were performed. Angiography showed LLE in the cephalic vein of the AVF that had been treated by DCB angioplasty. Angioscopy showed that the intima of the vessel had almost completely healed, and the paclitaxel particles had disappeared. LLE might occur when DCB is used for AVF.

#1578 Left ventricular ejection fraction: association with risk of mortality and the incidence of AVF dysfunction

Abstract Background and Aims Ejection fraction (EF) and chronic heart failure (HF) are often considered as criteria for the possibility of arteriovenous fistula (AVF) creation in relation to an increased risk of death, without sufficient evidence for this. There is, however, rare but compelling evidence that low EF increases the risk of AVF dysfunction. Aims: to evaluate the association between EF at the time of AVF creation and the incidence of adverse cardiovascular events, all-cause mortality, as well as AVF dysfunction Method This retrospective cohort study included 962 adult patients who had a first-time created functioning AVF. Only patients with a more than three months period after AVF creation and within a five-year period were included. The mean follow-up period was 34 ± 13 months. Four groups were identified based on EF and the presence of HF at the time of AVF creation (transthoracic echocardiogram): HF with reduced EF (rEF) &amp;lt;40%, with mid-range (mrEF) of 40-49%, or with preserved EF (pEF) ≥50% + HF, and a “no HF” group with EF ≥50% and no HF. Results In the univariate analysis, a reduced EF was associated with an increased risk of mortality, with the hazard ratios (HRs) of 2.706 [95% CI 1.330; 5.507], p = 0.006 for mrEF and 8.250 [95% CI 2.621; 25.97], p &amp;lt; 0.001 for rEF, compared to the “no HF” group (here and thereafter)—Fig. 1. However, after adjusting for age, sex, and Charlson Comorbidity Index (CCI), the EF was not significantly associated with the risk of death. Only the CCI score remained a significant factor (HR = 1.748 [95% CI 1.482; 2.063], p &amp;lt; 0.001). A decreased EF was associated with the incidence of AVF dysfunction both in the univariate analysis and after adjustments. In the univariate analysis, the incidence rate ratios (IRRs) of 6.88 [95% CI 3.88; 12.1], p &amp;lt; 0.001 for mrEF, and 19.9 [95% CI 8. 64; 41.6], p &amp;lt; 0.001 for rEF, were shown. After adjusting for age, sex, and CCI, the IRR for mrEF was 8.96 [95% CI 5.81; 13.7], p &amp;lt; 0.001, and for rEF it was 23.4 [95% CI 13.8; 38.6], p &amp;lt; 0.001. Even in the presence of polycystic kidney disease and diabetes mellitus in the fully adjusted model, the association between EF and the incidence of AVF dysfunction remained statistically significant: the IRR was 8.61 [95% CI 5.61; 13.1], p &amp;lt; 0.001 for mrEF, and 33.4 [95% CI 19.5; 56.2], p &amp;lt; 0.001 for rEF. The findings were confirmed in a sensitivity analysis that included adjustments for unplanned onset of dialysis and competing risks survival analysis (death—outcome of interest, conversion of HD to PD or kidney transplantation and conversion of AVF to CVC—competing events). According to our results patients with EF&amp;lt;40% will inevitably lose AVF function for various reasons within 3.5 years—Fig. 2. Meanwhile, this approach will give the patient additional time of HD via AVF, but not CVC, without increasing the risk of death, subject to Qa monitoring. Conclusion In patients with CKD 5 who are initiating treatment with maintenance hemodialysis, a decreased EF is associated to a greater extent with a higher risk of AVF dysfunction than with an increased risk of mortality. The burden of comorbidities, rather than a standalone assessment of EF, is one of the major risk factors determining patient survival.

Paclitaxel-coated Balloon (PCB) Intervention for Dysfunctional Arteriovenous Fistulas: 1-year Experience in a Single Center in Latin America

Paclitaxel-coated Balloon (PCB) Intervention for Dysfunctional Arteriovenous Fistulas: 1-year Experience in a Single Center in Latin America

The influence of near-infrared therapy on arteriovenous fistula patency in haemodialysis patients: A multicentre, randomised, controlled clinical trial.

Arteriovenous fistula (AVF) is the preferred vascular access for patients undergoing haemodialysis (HD). AVF malfunction remains a major clinical problem and is a significant independent risk factor for death. Although far-infrared (FIR) therapy has been shown to reduce complications and improve the patency rate of AVFs in various studies, it has been cautiously recommended by the Kidney Disease Outcome Quality Initiative (KDOQI) guidelines for AVF care due to insufficient evidence. Therefore, it is necessary to identify more effective methods for preventing AVF dysfunction. Many in vitro studies and few clinical studies have examined the effects of near-infrared (NIR) therapy on the vasculature. This study will examine the effects of NIR therapy on AVF. A randomised, controlled, open-label, multicentre trial will compare the effect of NIR on AVF patency after 1 year of therapy with that of a control group of patients with existing AVF. One group of patients received NIR treatment above their AVFs, whereas the control group received regular care. The primary outcome is the primary fistula patency rate within 12 months. In addition, acute changes in inflammatory, vasodilatory and haemodynamic parameters after a single treatment in the first 40 participants will be examined. This study was registered in the Clinical Trials Registry (ChiCTR2300071305) at https://register.clinicaltrials.gov/. This study will explore the long-term and acute effects of NIR on AVFs. The study findings will provide information that can be used to develop new technical support for the prevention of AVF dysfunction in patients undergoing haemodialysis.

Snuffbox distal transradial access (dTRA) for arteriovenous fistuloplasty in Singapore: Going distal is safe.

Arteriovenous fistula (AVF) dysfunction resulting from stenosis or occlusion, is a prevalent issue in end-stage renal failure patients reliant on autogenous AVFs for dialysis. Recently, a distal transradial approach (dTRA) has emerged, offering advantages such as diminished access site complications, better patient comfort and reduced risk of radial artery occlusion. Our study seeks to assess the effectiveness, outcomes and complication rates of employing dTRA for arteriovenous fistuloplasty in Singaporean patients. A retrospective review of all dTRA fistuloplasties performed on dysfunctional or slow to mature AVFs from 2017 to 2023 in our institution was performed. Patients with a distal radial artery measuring 2 mm or more with no evidence of occlusion or thrombosis were included. Patients who required central venoplasty or cutting balloon angioplasty were excluded. Outcome measures included technical success, mean procedure duration, complications and post-intervention primary patency at 1, 3 and 6 months. Patients were followed up for 12 months post-intervention. A total of 37 patients were included. 97.3% of patients undergoing dTRA fistuloplasty had radiocephalic fistulas while 2.7% had brachiobasilic fistulas. There was 100% technical success (defined as success in radial artery cannulation, sheath insertion and crossing of stenotic lesions) in our study as all patients successfully underwent fistuloplasty via dTRA approach. One-month patency rate was 97.4%, 3-month patency rate was 92.1% and 6-month patency rate was 86.8%. There were no immediate complications (haematoma, infection, bleeding, pseudoaneurysm, occlusion) of the radial artery post-intervention. Our paper illustrates the safety and efficacy of utilising dTRA for arteriovenous fistuloplasty. This approach offers distinct benefits in addressing non-mature or dysfunctional distal forearm arteriovenous fistulas and should be taken into account in anatomically suitable cases.

Retrospective analysis of predictive factors for AVF dysfunction in patients undergoing MHD.

To construct an early clinical prediction model for AVF dysfunction in patients undergoing Maintenance Hemodialysis (MHD) and perform internal and external verifications. We retrospectively examined clinical data from 150 patients diagnosed with MHD at Hefei Third People's Hospital from January 2014 to June 2023. Depending on arteriovenous fistula (AVF) functionality, patients were categorized into dysfunctional (n = 62) and functional (n = 88) cohorts. Using the least absolute shrinkage and selection operator(LASSO) regression model, variables potentially influencing AVF functionality were filtered using selected variables that underwent multifactorial logistic regression analysis. The Nomogram model was constructed using the R software, and the Area Under Curve(AUC) value was calculated. The model's accuracy was appraised through the calibration curve and Hosmer-Lemeshow test, with the model undergoing internal validation using the bootstrap method. There were 11 factors exhibiting differences between the group of patients with AVF dysfunction and the group with normal AVF function, including age, sex, course of renal failure, diabetes, hyperlipidemia, Platelet count (PLT), Calcium (Ca), Phosphorus, D-dimer (D-D), Fibrinogen (Fib), and Anastomotic width. These identified factors are included as candidate predictive variables in the LASSO regression analysis. LASSO regression identified age, sex, diabetes, hyperlipidemia, anastomotic diameter, blood phosphorus, and serum D-D levels as 7 predictive factors. Unconditional binary logistic regression analysis revealed that advanced age (OR = 4.358, 95% CI: 1.454-13.062), diabetes (OR = 4.158, 95% CI: 1.243-13.907), hyperlipidemia (OR = 3.651, 95% CI: 1.066-12.499), D-D (OR = 1.311, 95% CI: 1.063-1.616), and hyperphosphatemia (OR = 4.986, 95% CI: 2.513-9.892) emerged as independent risk factors for AVF dysfunction in MHD patients. The AUC of the predictive model was 0.934 (95% CI: 0.897-0.971). The Hosmer-Lemeshow test showed high consistency between the model's predictive results and actual clinical observations (χ2 = 1.553, P = .092). Internal validation revealed an AUC of 0.911 (95% CI: 0.866-0.956), with the Calibration calibration curve nearing the ideal curve. Advanced age, coexisting diabetes, hyperlipidemia, blood D-D levels, and hyperphosphatemia are independent risk factors for AVF dysfunction in patients undergoing MHD.

Efficacy of drug-coated balloon catheters for patients with short-term recurrent dysfunction of arteriovenous fistula.

In this study, we aimed at clarifying the usefulness of drug-coated balloon catheters (DCBs) for arteriovenous fistulas (AVFs) that repeatedly undergo restenosis over a short period and to examine the factors that influence the patency period after DCB use. This retrospective observational study was conducted using IN.PACT AV in 29 cases of AVFs with repeated restenosis within approximately 3 months, and temporary patency before and after DCB use in the same patients was compared. For target participants, the flow volume, resistive index (RI), and vascular diameter of the brachial artery were measured using an ultrasound diagnostic device. Stenosis diameter, reference vessel diameter, and stenosis length of the lesion were measured before and after DCB dilatation using digital subtraction angiography. Before DCB angioplasty, the postintervention primary patency at 3 months was 66%, and the average interval was 92 ± 21 days (mean ± standard deviation). After DCB angioplasty, the postintervention primary patency rates at 3 and 6 months were 92% and 36%, respectively. The postintervention primary patency was significantly higher after than before DCB angioplasty (p < 0.0001). A sub-analysis was performed on 25 patients who were followed up for 4 months or more after DCB. The RI values before and after dilatation with DCB significantly differed between the patency group 4 or more months after DCB and the patency group less than 4 months after DCB. For AVFs that require frequent PTA over a short period of time, DCB improved the patency rate 3 months after PTA, but the improvement effect at 6 months was limited. The effect of DCB on prolonging the patency rate of AVFs that require frequent PTA over a short period of time may be correlated with the RI value before and after PTA.

Accuracy of 3.0T magnetic resonance angiography for the detection of arteriovenous fistula dysfunction in hemodialysis patients requiring interventional therapy: a prospective study.

Color Doppler ultrasonography (CDUS) is feasible to detect arteriovenous fistula (AVF) dysfunction in hemodialysis patients but is not sufficient to map the structure of fistula required for interventions. This study is designed to evaluate the diagnostic accuracy of three-dimensional time-of-flight magnetic resonance angiography (TOF-MRA) at 3.0T versus CDUS for AVF dysfunction, by using digital subtraction angiography (DSA) as reference. This prospective study enrolled 68 consecutive patients with dysfunctional AVF who underwent both CDUS and TOF-MRA at Shanghai Sixth People's Hospital affiliated to Shanghai Jiao Tong University School of Medicine. The analysis of the dysfunctional AVFs was divided into three regions: the feeding artery, fistula and draining veins. In the whole- and per-regional-based analyses, two observers who were blinded to the clinical and DSA results independently analyzed all CDUS and TOF-MRA datasets. The image quality and stenosis severity of the lesions on TOF-MRA were evaluated. A receiver operating characteristic curve was applied to analyze the detection of AVF dysfunction with TOF-MRA. A total of 204 vessel regions were evaluated. The whole-region-based image quality of TOF-MRA was poorer in patients with a total occlusion (1.8±0.8) than in those with stenosis (2.7±0.6, P<0.001). In the whole-region analyses, TOF-MRA had higher sensitivity [99.1% (94.6-100.0%) vs. 82.9% (74.6-89.0%), P<0.001] and similar specificity [93.1% (85.0-97.1%) vs. 94.3% (86.5-97.9%), P=0.755] than CDUS. The per-region-based analyses showed that TOF-MRA yielded higher sensitivity [fistula region, 98.1% (88.4-99.9%) vs. 80.8% (67.0-89.9%); P=0.004; draining vein region, 100.0% (92.5-100.0%) vs. 85.0% (72.9-2.5%); P=0.003] and similar specificity [fistula region, 88.2% (62.3-97.8%) vs. 88.2% (62.3-97.9%); P>0.99; draining vein region, 100.0% (59.8-100.0%) vs. 87.5% (46.7-99.3%); P>0.99] than CDUS. Sensitivity and specificity of TOF-MRA were comparable to those of CDUS in feeding artery region. TOF-MRA is a feasible and accurate method to display AVF dysfunction in hemodialysis patients, and this method might fulfill the endovascular treatment planning requirements.