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Arteriovenous fistula is an abnormal connection between arteries and veins occurring usually following surgery, trauma, catheterization, or local procedures. Spontaneous arteriovenous fistulas are a rare clinical entity with very few cases reported in the literature with unclear mechanisms. We present a case report of a 54‐year‐old Ethiopian female with known chronic kidney disease on hemodialysis for 2 years thrice a week who presented with progressive pulsatile right thigh mass of 7 months duration in the absence of trauma, catheter insertion previously, or surgery. The arteriovenous fistula was confirmed by computed tomography angiography and it was intervened with open surgery with no complication. [ABSTRACT FROM AUTHOR]

This review presents a comprehensive analysis of vascular access in hemodialysis, focusing on the current modalities, their associated challenges, and recent technological advancements. It closely examines the status of three primary types of vascular access: arteriovenous fistulas, arteriovenous grafts, and central venous catheters. The review delves into the complications and pathologies associated with these access types, emphasizing the mechanobiology-related pathogenesis of arteriovenous access. Furthermore, it explores recent clinical trials, biomaterials, and device innovations, highlighting novel pharmaceutical approaches, advanced materials, device designs, and cutting-edge technologies aimed at enhancing the efficacy, safety, and longevity of vascular access in hemodialysis. This synthesis of current knowledge and emerging trends underscores the dynamic evolution of vascular access strategies and their critical role in improving patient care in hemodialysis.

Chronic kidney disease (CKD) is an increasingly prevalent pathology in today's society. The prevalence of CKD increases progressively with aging, together with other diseases such as type 2 diabetes, high blood pressure, and arteriosclerosis. In patients with advanced chronic kidney disease, vascular access is required to start hemodialysis as renal replacement therapy. Vascular access for hemodialysis becomes the key point of treatment since without functioning vascular access there is no possibility of performing it. Creation of an arteriovenous fistula (AVF) in the upper extremity for hemodialysis; connects the arteries and veins of the upper body. It can be a native connection or a polytetrafluoroethylene grafted connection. The native AVF is preferred as the ideal type of vascular access, mainly because of its long duration, longer survival, and low complication rate. AVF can be performed in any upper extremity without complications, but the general advice is to choose the nondominant arm first, to encourage and support the patient's movement in the dominant extremity, and to provide as much comfort as possible during hemodialysis sessions. [ABSTRACT FROM AUTHOR]

Objectives The aim of this study was to compare the outcomes of the transjugular approach with those of the conventional approach for endovascular treatment of arteriovenous fistulas (AVFs). Methods Between May 2015 and July 2019, 112 patients with endovascular treatment of dysfunctional or immature AVFs were included and divided into the transjugular (n  = 46) and conventional (n  = 66) groups. Electronic medical records and angiography of the patients were retrospectively reviewed to assess technical and clinical success rates, time to first fistulography, total procedure time, primary and secondary patency, and complications in both groups. Results There were no significant differences in technical success rate (87.0% vs 97.0%; P  =  .062), clinical success rate (80.4% vs 90.9%; P  =  .109), or total procedure time (60.2 vs 57.9 min; P  =  .670) between the groups. Cox proportional hazards models showed that the cumulative primary patency was significantly higher in the transjugular group than in the conventional group (P  =  .041; 6-month patency rates, 93.8% vs 91.5%). Also, a statistically significant difference was found between the cumulative secondary patency of the groups (P  =  .014; 6-month patency rates, 91.4% vs 86.5%). No major complications were observed. Conclusions Transjugular endovascular treatment of AVFs was successful and effective. Longer patency periods were observed when treated via transjugular access. Advances in knowledge This article compared the outcomes of transjugular approaches with those of conventional approaches in the endovascular treatment of native AVFs and showed higher patency periods/rates in the transjugular group than in the conventional group. [ABSTRACT FROM AUTHOR]

Objective: This study investigated the role of the P2Y12 receptor in autogenous arteriovenous fistula (AVF) failure resulting from stenosis. Methods: Stenotic venous tissues and blood samples were obtained from patients with end-stage renal disease (ESRD) together with AVF stenosis, while venous tissues and blood samples were collected from patients with ESRD undergoing initial AVF surgery as controls. Immunohistochemistry and/or immunofluorescence techniques were utilized to assess the expression of P2Y12, transforming growth factor-β1 (TGF-β1), monocyte chemotactic protein 1 (MCP-1), and CD68 in the venous tissues. The expression levels of P2Y12, TGFβ1, and MCP-1 were quantified using quantitative reverse transcription-polymerase chain reaction and western blot analyses. Double and triple immunofluorescence staining was performed to precisely localize the cellular localization of P2Y12 expression. Results: Expression levels of P2Y12, TGFβ1, MCP-1, and CD68 were significantly higher in stenotic AVF venous tissues than in the control group tissues. Double and triple immunofluorescence staining of stenotic AVF venous tissues indicated that P2Y12 was predominantly expressed in α-SMA-positive vascular smooth muscle cells (VSMCs) and, to a lesser extent, in CD68-positive macrophages, with limited expression in CD31-positive endothelial cells. Moreover, a subset of macrophage-like VSMCs expressing P2Y12 were observed in both stenotic AVF venous tissues and control venous tissues. Additionally, a higher number of P2Y12 +/TGF-β1+ double-positive cells were identified in stenotic AVF venous tissues than in the control group tissues. Conclusion: Increased expression of P2Y12 in stenotic AVF venous tissues of patients with ESRD suggests its potential involvement in the pathogenesis of venous stenosis within AVFs. [ABSTRACT FROM AUTHOR]

Giant femoral arteriovenous fistulas are comparatively uncommon, typically treated through covered stents, coil embolization, and open surgical repair. Nevertheless, these options may not be appropriate for all patients. Herein, we describe a case of traumatic femoral arteriovenous fistulas that led to drastic dilatation of the femoral arteriovenous system and considerable heart failure symptoms due to prolonged lack of treatment. Given the intricate anatomical location of the fistula and the patient's severe cardiac dysfunction, surgical repair is often unfeasible. Consequently, we adopted an innovative approach in this case, utilizing a ventricular septal occluder device for fistula closure. This constitutes the first report of an arteriovenous fistula transcatheter closure with a septal occluder.

The failure of arteriovenous fistulas (AVFs) following intimal hyperplasia (IH) increases morbidity and mortality rates in patients undergoing hemodialysis for chronic kidney disease. The peroxisome-proliferator associated receptor (PPAR-γ) may be a therapeutic target in IH regulation. In the present study, we investigated PPAR-γ expression and tested the effect of pioglitazone, a PPAR-γ agonist, in different cell types involved in IH. As cell models, we used Human Endothelial Umbilical Vein Cells (HUVEC), Human Aortic Smooth Muscle Cells (HAOSMC), and AVF cells (AVFCs) isolated from (i) normal veins collected at the first AVF establishment (T0), and (ii) failed AVF with IH (T1). PPAR-γ was downregulated in AVF T1 tissues and cells, in comparison to T0 group. HUVEC, HAOSMC, and AVFC (T0 and T1) proliferation and migration were analyzed after pioglitazone administration, alone or in combination with the PPAR-γ inhibitor, GW9662. Pioglitazone negatively regulated HUVEC and HAOSMC proliferation and migration. The effect was antagonized by GW9662. These data were confirmed in AVFCs T1, where pioglitazone induced PPAR-γ expression and downregulated the invasive genes SLUG, MMP-9, and VIMENTIN. In summary, PPAR-γ modulation may represent a promising strategy to reduce the AVF failure risk by modulating cell proliferation and migration. [ABSTRACT FROM AUTHOR]

To investigate the primary patency and risk factors in hemodialysis patients with autogenous arteriovenous fistula (AVF). Methods The patients with new creation of AVF at a single institution from Sep 2016 to Apr 2019 were enrolled in this prospective study. Clinical data including demographic data, ultrasound data, concomitant diseases, operative information and primary patency were collected and analyzed. Kaplan-Meier survival curves and Cox proportional hazard models were used to determine the primary patency and associated factors. Results The primary patency rates for 1,2 and 3 years were 77.5%,71.5% and 65.1%,respectively. The median time of primary patency was 35.85 months. Univariate Cox regression reveals that age, education level, nephrology follow-up, diabetes, initial surgery, fistula site, central venous catheter, arterial diameter and venous diameter were the composite risk factors of primary patency． After adjustment,multivariate Cox regression revealed that diabetes, initial surgery and venous diameter were the independent factors for AVF primary patency.Conclusion Diabetes, initial surgery and venous diameter were significantly associated with primary patency in newly created AVF. [ABSTRACT FROM AUTHOR]

Cephalic vein ≤ 2.5 mm is associated with high failure rate. Preoperative balloon angioplasty in ≤ 2 mm veins improve the patency rate of arteriovenous fistula (AVF) compared with hydrostatic technique. This study was done to determine difference in the efficacy between two surgical techniques (hydrostatic dilatation with balloon angioplasty (HD + BA) versus hydrostatic dilatation with malleable dilatation (HD + MD)) on patency rates of AVF in patients with cephalic veins ≤ 2 mm in diameter. This randomized controlled trial was conducted in the Department of Surgical Disciplines, AIIMS, New Delhi between 2017 and 2018. Two hundred patients of chronic kidney disease (CKD) were evaluated for AVF, 120/200 (60%) agreed to participate in the study. Computer generated randomization via sealed envelope was done into two groups, i.e., HD + BA (n = 60) or HD + MD (n = 60). Efficacy on clinical maturation (CM) and radiological maturation (RM) of AVF was observed. CM—use of AVF for repetitive (≥ 3) hemodialysis. RM—cross-sectional diameter > 4 mm and intra-access flow rate > 500 ml/h. CM and RM between HD + BA versus HD + MD at the end of 8 and 24 weeks was 83.63% and 58.2%: 83.6% and 58.11% versus 85.71% and 64.3%: 82.1% and 64.28% (p values 0.81 and 0.51: p value 0.83 and 0.29). CM and RM in brachiocephalic AVF (BCAVF) subgroup at 24 weeks was 40/43 (93.0%) and 30/43 (69.70%). CM and RM in RCAVF subgroup at 24 weeks were 52/68 (76.4%) and 38/68 (55.8%). Both surgical techniques were equally effective in increasing the patency of AVF. HD + BD is not superior to HD + MD at 6 months of follow-up. Trail registration: CTRI/2017/05/008543, Registered on 12/5/2017. [ABSTRACT FROM AUTHOR]

Objective: This retrospective, single centre, comparative effectiveness study aimed to compare the long term outcomes of percutaneous arteriovenous fistulae (pAVF) and surgically created arteriovenous fistulae (sAVF) created in the proximal forearm for haemodialysis access., Methods: Data were reviewed from a prospectively maintained database on patients who underwent pAVF or sAVF creation from September 2017 to September 2023. A total of 217 pAVFs (61 WavelinQ and 156 Ellipsys) and 158 sAVFs were analysed. Outcome measures included technical success, maturation, patency, time to first successful use, re-interventions, and complications., Results: Technical success was 100% for sAVF and Ellipsys, and 93.4% for WavelinQ (p < .001). Maturation at four weeks was higher in Ellipsys (78.6%) and sAVF (79.7%) groups than in WavelinQ (64.9%) (p = .042). Median time to first cannulation was shortest for Ellipsys (57 days), followed by sAVF (73 days), and longest for WavelinQ (98.6 days) (p = .048). Average follow up was 654 days (interquartile range 164, 1 049 days; range 0 - 2 061 days). Primary patency was higher in sAVF than in pAVFs. The Cox proportional hazard ratio (HR) for loss of primary patency was 1.50 for WavelinQ and 1.42 for Ellipsys compared with sAVF (p = .045). Secondary patency was statistically significantly lower for WavelinQ (HR 2.76; p < .001), but not for Ellipsys (HR 0.74; p = .33). Haemodialysis access induced distal ischaemia (HAIDI) was more common in the sAVF group with nine events (5.7%) compared with one for the Ellipsys (0.64%; p = .008). Re-intervention rates per patient year were comparable across groups (0.60 vs. 0.61 vs. 0.69 for sAVF, WavelinQ, and Ellipsys, respectively)., Conclusion: This study indicates that while all access types can provide long term functional haemodialysis access, sAVFs perform better in some outcome domains and pAVFs (particularly Ellipsys) in others, with sAVF showing higher rates of HAIDI, yet lower rates of juxta-anastomotic stenosis. The findings underscore the importance of personalised vascular access planning, weighing immediate procedural outcomes against long term functionality., (Copyright © 2025 European Society for Vascular Surgery. Published by Elsevier B.V. All rights reserved.)

Abstract Background Arteriovenous fistula (AVF) is the most important vascular access for hemodialysis; however, preventive treatment to maintain the patency of AVFs has not been developed. In endothelium, β-catenin functions in both the intercellular adherens complex and signaling pathways that induce the transition of endothelial cells to myofibroblasts in response to mechanical stimuli. We hypothesize that mechanical disturbances in the AVF activate β-catenin signaling leading to the transition of endothelial cells to myofibroblasts, which cause AVF thickening. The present study aimed to test this hypothesis. Methods Chronic kidney disease in mice was induced by a 0.2% adenine diet. AVFs were created by aortocaval puncture. Human umbilical vein endothelial cells (HUVECs) were used in the cell experiments. A pressure-culture system was used to simulate mechanical disturbances of the AVF. Results Co-expression of CD31 and smooth muscle alpha-actin (αSMA), loss of cell–cell adhesions, and the expression of the myofibroblast marker, integrin subunit β6 (ITGB6), indicated transition to myofibroblasts in mouse AVF. Nuclear translocation of β-catenin, decreased axin2, and increased c-myc expression were also observed in the AVF, indicating activated β-catenin signaling. To confirm that β-catenin signaling contributes to AVF lesions, β-catenin signaling was inhibited with pyrvinium pamoate; β-catenin inhibition significantly attenuated AVF thickening and decreased myofibroblasts. In HUVECs, barometric pressure-induced nuclear localization of β-catenin and increased expression of the myofibroblast markers, αSMA and ITGB6. These changes were attenuated via pretreatment with β-catenin inhibition. Conclusions The results of this study indicate that mechanical disturbance in AVF activates β-catenin signaling to induce the transition of endothelial cells to myofibroblasts. This signaling cascade can be targeted to maintain AVF patency.

Objective: Hemodialysis adequacy in end-stage renal disease patients plays a crucial role in their quality of life. Repeated stenosis at the anastomotic site of arteriovenous fistula and synthetic arteriovenous graft are a major cause of access failure resulting in hospitalization, catheter usage, and contributing substantially to increased health care costs. Although standard plain balloon angioplasty (PBA) is successful, the patency rate over time is often poor. Drug-coated balloons (DCB) delivering an anti-restenosis agent, Paclitaxel, may improve patency. In this study, we aimed to investigate whether there is an increase in primary patency rate in drug-coated balloon angioplasty compared to conventional plain balloon angioplasty. Materials and Methods: We performed a retrospective analysis of 55 patients with stenotic arteriovenous fistulas (AVF), and arteriovenous grafts (AVG) treated with DCB or PBA. Thirty-five patients were treated with drug-coated balloons, while twenty patients were treated with the standard plain balloon angioplasty. Follow up assessment was scheduled at three months, six months, and nine months. Our primary outcome was the primary patency rate, defined as the interval from the time of intervention until hemodialysis inadequacy. Results: There were 55 patients including twenty-one males and thirty-four females participated in the study. The average age of the 55 patients was 65.43 ± 12.89 years. Thirty (54.5%) patients were diabetes mellitus and 40 (72.7%) patients had hypertension. Seven patients (12.7%) had dyslipidemia. Eight patients (14.5%) had ischemic heart disease. And four patients (7.3%) had hyperparathyroidism. No significant differences in patency rate were found between gender, age group and patients’ underlying diseases. The proportion of primary patency rate comparing between the DCB and PBA treatment was 96.3% versus 73.9% at 6 months (P=0.017) and 92.6% versus 40% at 9 months (P<0.001). After multivariable analysis was performed (adjusted for sex, age, and underlying diseases), we found that stenosis was more likely to occur in patients who had undergone plain balloon angioplasty rather than drug-coated balloon angioplasty (HR 15.75; 95% CI 2.5%-99.1%, P=0.003). Conclusion: Drug-coated balloon angioplasty, when compared with plain balloon angioplasty, achieves a more desirable primary patency rate at 6 months and 9 months after the procedure. [ABSTRACT FROM AUTHOR]

BackgroundUterine intravenous leiomyomatosis (IVL), a rare type of uterine leiomyoma, is defined by the intravascular proliferation of a histologically benign smooth muscle cell tumor. Pelvic arteriovenous fistula (AVF) is a rare vascular malformation that is most commonly congenital, post-traumatic, or iatrogenic. The link between leiomyomatosis and AVF has received little attention in the medical literature.ResultsWe provide a case series of seven patients, four of whom were from our center, who had IVL complicated by a pelvic AVF. The symptoms of right heart failure were noted as swelling in the abdomen and two legs as well as a significant amount of ascites. Coil embolization of AVFs may be beneficial in minimizing bleeding during IVL surgery. A review of all accessible literature published on IVLs from 2000 to 2020 was conducted, and data were retrieved from 78 papers totaling 262 cases. Complications and recurrence were associated with pelvic mass excision and intravascular remnant tumor, respectively.ConclusionIntravenous leiomyomatosis combined with AVF aggravates congestion symptoms of surrounding organs. It is worth noting the uncommon combination of AVF and IVL, stressing the importance of a thorough assessment and surgical approach in IVL treatment.

Objective: Hemodialysis adequacy in end-stage renal disease patients plays a crucial role in their quality of life. Repeated stenosis at the anastomotic site of arteriovenous fistula and synthetic arteriovenous graft are a major cause of access failure resulting in hospitalization, catheter usage, and contributing substantially to increased health care costs. Although standard plain balloon angioplasty (PBA) is successful, the patency rate over time is often poor. Drug-coated balloons (DCB) delivering an anti-restenosis agent, Paclitaxel, may improve patency. In this study, we aimed to investigate whether there is an increase in primary patency rate in drug-coated balloon angioplasty compared to conventional plain balloon angioplasty. Materials and Methods: We performed a retrospective analysis of 55 patients with stenotic arteriovenous fistulas (AVF), and arteriovenous grafts (AVG) treated with DCB or PBA. Thirty-five patients were treated with drug-coated balloons, while twenty patients were treated with the standard plain balloon angioplasty. Follow up assessment was scheduled at three months, six months, and nine months. Our primary outcome was the primary patency rate, defined as the interval from the time of intervention until hemodialysis inadequacy. Results: There were 55 patients including twenty-one males and thirty-four females participated in the study. The average age of the 55 patients was 65.43 ± 12.89 years. Thirty (54.5%) patients were diabetes mellitus and 40 (72.7%) patients had hypertension. Seven patients (12.7%) had dyslipidemia. Eight patients (14.5%) had ischemic heart disease. And four patients (7.3%) had hyperparathyroidism. No significant differences in patency rate were found between gender, age group and patients’ underlying diseases. The proportion of primary patency rate comparing between the DCB and PBA treatment was 96.3% versus 73.9% at 6 months (P=0.017) and 92.6% versus 40% at 9 months (P

A machine learning (ML) algorithm is successfully developed to assess the signal quality of measured photoplethysmography (PPG) waveforms for effective real-time prediction of blood flow volume (BFV). This algorithm is essential to achieve high prediction accuracy of BFV for hemodialysis patients to monitor the quality of their arteriovenous fistulas (AVFs) at home by themselves using a new hand-held device. The algorithm is built on an ML classifier of 1-dimensional convolutional neural network (1D-CNN), calibrated by two groups of PPG waveforms that are pre-identified by experienced experts to 300 qualified and 202 un-qualified PPG waveforms in 6-second windows, as the ones to render accurate BFV predictions and the others to inaccurates, respectively. The qualified ones satisfy at least the deterministic criteria such as adequate signal-to-noise-ratio (SNR), stable/small fluctuations of AC/DC components, and also the presence of secondary bio-features, to ensure minimized influence from mis-positioning, hand movement, pressurization and varied ambient lighting. With the classifier algorithm in hand, together with another fully-connected neural network for estimating BFV, a combined real-time computation algorithm is built, being able to achieve much better accuracy for real-time measurement ubiquitously. In results, using the newly-developed quality-assessment algorithm, the error of predicted BFVs is improved from ±175.577 ml/min to ±122.8259 ml/min significantly. [ABSTRACT FROM AUTHOR]

Background: Arteriovenous fistula (AVF) failure can occur in patients undergoing hemodialysis (HD). In this study, we explored the correlation between hyperlipidemia and AVF failure in patients undergoing HD. Moreover, we compared the lipid profiles of patients with chronic kidney disease (CKD) with those of healthy people to provide a basis for lipid-lowering in patients undergoing HD., Method and Analysis: We searched PubMed, Web of Science, Embase, the Cochrane library, CNKI, CBM, the China Science Periodical Database, and the China Science and Technology Journal Database. The final search was conducted on August 31, 2021, and the search period was restricted between 2000 and August 31, 2021, without publication restrictions. All studies met the inclusion criteria, and the influences of sex, age, geographical location, diagnosis method, and publication year were excluded. The data were analyzed using the random-effects model and the fixed-effects model., Results: Twenty-eight studies were included in the meta-analysis with 121,666 patients in the CKD group and 1714 patients in the AVF failure group. Triglyceride concentration in patients with CKD was higher than in healthy subjects (MD: -31.56, 95% CI: -41.23 to -21.90, p  < 0.00001). A high total cholesterol (TC) concentration (MD: 6.97, 95% CI: 2.19-11.74, p  = 0.004) and a high low-density lipoprotein cholesterol (LDL-C) concentration (MD: 23.83, 95% CI: 18.48-29.18, p  < 0.00001) were associated with AVF failure. Furthermore, HDL-C was lower in the AVF failure group than in the AVF patency group (MD: -2.68, 95% CI: -4.60 to -0.76, p  = 0.006)., Conclusion: Our analysis indicates that the AVF failure may be related to the increase of TC/LDL-C and the decrease of HDL-C. Although current guidelines do not consider intensive lipid-lowering therapy as necessary in patients undergoing HD, our research indicates that patients with AVF undergoing HD may need regular TC/LDL-C-lowering therapy to prevent AVF failure. However, this issue still needs well designed prospective trials., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Objective: to analyze the outcomes of arteriovenous fistula (AVF) constructed in our setup. Study Design: Retrospective observational study. Place and Duration of Study: Combined Military Hospital, Lahore, from Mar 2019 to Mar 2020. Methodology: Our study included all the patients who had their arteriovenous fistula (AVF) made during the study period. Data was collected via telephone calls, to inquire about the status of AV fistula after one year of AV fistula construction surgery. Results: Out of 130 study participants, 97 were successfully contacted. Mean age of patients was 54 .39 ± 12.75 years. Majority were male patients (71.1%) and had their first dialysis via temporary dialysis access catheter. Most of the patients (74.7%) had functional AVF. 35 (36.1%) patients were not alive at the time of contact. In 9 (9.2%) patients, AV fistula failed with the most common cause being thrombosis (77.7%). Conclusion: Current study is one of the pioneer in Pakistan where we have started to audit our performance as the dedicated access surgeons. It is high time for us to evaluate our performance so that better outcome can be offered to the dialysis dependent patients. [ABSTRACT FROM AUTHOR]

Introduction Arteriovenous fistulas (AVFs) are the preferred choice for long-term hemodialysis because of their low rates of complications and associated costs compared with other forms of accesses. One of these complications is the susceptibility to stenoses and subsequent thrombotic occlusion. The aim of this study is to establish a valid classification for thrombosed AVFs based on their thrombus load and to describe different procedures for AVF salvage based on this classification. Patients and methods In this prospective study, 90 patients with failed AV access were enrolled in this study and divided into three groups based on the thrombus load within the vein of the AV access based on clinical and ultrasonographic assessment. The diameter of the thrombosed vein was measured and accordingly the three groups were divided into: Group A: minimal thrombus load (diameter less than 6 mm). Group B: moderate thrombus load (diameter more than 6 mm and less than 12 mm or the presence of one aneurysm within the vein with a diameter less than 2 cm). Group C: high thrombus load (diameter: more than 12 mm or the presence of more than one aneurysm within the vein or the presence of any aneurysm >2 cm in diameter). Patients were subjected to angioplasty with or without thrombectomy according to their classification and were monitored for functional outcome and patency rates. Results The success rate was 95.1% in group A, 90.9% in group B, and 87.5% in group C. Over a period of 1, 3, and 6 months postoperatively, the primary patency rates were 94.8%, 91.5%, and 89.2% in group A, 89.3%, 87.0%, and 84.2 in group B, and 85.7%, 81.9%, and 75% in group C, respectively. Conclusion Thrombosed AVFs are amenable for salvage whatever their thrombus load. There is no statistical difference in the patency of salvaged AVFs with variable thrombus load among the three groups. [ABSTRACT FROM AUTHOR]

Referral time for end-stage renal disease (ESRD) patients to nephrologists and initial vascular access method are considered significant factors that impact health outcomes at the time of hemodialysis (HD) initiation. Native arteriovenous fistula (AVF) is strongly recommended as initial access. However, little is known about the referral rate among ESRD receiving HD in Palestine and its correlation with AVF creation. In Ramallah Hemodialysis Center, we investigated the pre-dialysis nephrology care and AVF usage in 156 patients. Type of access at HD initiation was temporary central venous catheter (CVC) in 114 (73%), tunneled hemodialysis catheter (TDC) in 21 (13%) and AVF in 21 (13%). Out of all participants, 120 (77%) were seen by nephrologist prior to dialysis. Of the participants who initiated dialysis with a CVC, 36 (31%) had not received prior nephrology care. All participants who initiated dialysis with functional AVF had received prior nephrology care. Patients who were not seen by a nephrologist prior to HD initiation had no chance at starting HD with AVF, whereas 17% of those who had nephrology care >12 months started with AVF. In conclusion, a relatively large percentage of Palestinian HD patients who were maintained on HD did not have any predialysis nephrology care. In addition, patients who received predialysis nephrology care were significantly more likely to start their HD through AVF whereas all those without predialysis nephrology care started through CVC. More in-depth national studies focusing on improving nephrology referral in ESRD patients are needed to increase AVF utilization.

The arteriovenous fistula (AVF) represents the favorite vascular access in individuals with chronic kidney disease (CKD). Because AVF is a guarantee of survival for these patients, proper surgical packing and a timely follow-up program is crucial. Although a good objective examination of the limb site of FAV provides useful information both in planning the fistula surgery and in its surveillance and monitoring, it is now well established that the advent of instrumental diagnostics (ultrasonography, digital angiography, Angio-TC, MRI) has contributed significantly to improving primary and secondary patency of FAV and early diagnosis of vascular access complications. In this area, clinical thermography, a noninvasive and nondestructive diagnostic technique for assessing minute surface temperature differences, has shown good potential for the assessment of AVF. In fact, thermographic analysis of a limb site of AVF shows an increase in temperature at the site of the anastomosis and along the course of the arterialized vein. In this article we report our experience on the use of thermography in preoperative evaluation and postoperative surgical packing of an AVF. Further studies could validate the use of clinical thermography as a diagnostic technique to be used in the field of hemodialysis vascular accesses., (Copyright by Società Italiana di Nefrologia SIN, Rome,Italy.)

Referral time for end-stage renal disease (ESRD) patients to nephrologists and initial vascular access method are considered significant factors that impact health outcomes at the time of hemodialysis (HD) initiation. Native arteriovenous fistula (AVF) is strongly recommended as initial access. However, little is known about the referral rate among ESRD receiving HD in Palestine and its correlation with AVF creation. In Ramallah Hemodialysis Center, we investigated the pre-dialysis nephrology care and AVF usage in 156 patients. Type of access at HD initiation was temporary central venous catheter (CVC) in 114 (73%), tunneled hemodialysis catheter (TDC) in 21 (13%) and AVF in 21 (13%). Out of all participants, 120 (77%) were seen by nephrologist prior to dialysis. Of the participants who initiated dialysis with a CVC, 36 (31%) had not received prior nephrology care. All participants who initiated dialysis with functional AVF had received prior nephrology care. Patients who were not seen by a nephrologist prior to HD initiation had no chance at starting HD with AVF, whereas 17% of those who had nephrology care >12 months started with AVF. In conclusion, a relatively large percentage of Palestinian HD patients who were maintained on HD did not have any predialysis nephrology care. In addition, patients who received predialysis nephrology care were significantly more likely to start their HD through AVF whereas all those without predialysis nephrology care started through CVC. More in-depth national studies focusing on improving nephrology referral in ESRD patients are needed to increase AVF utilization. [ABSTRACT FROM AUTHOR]

Pseudoaneurysm (PSA) formation, in an arteriovenous fistula (AVF) undergoing hemodialysis, can occur as a result of frequent venipunctures and can lead to a weakened vessel wall. Since many dialysis patients' lives depend on their weekly hemodialysis sessions, complications that result from dialysis require treatment. A PSA can be a life-threatening complication, especially for these patients. Sonography has been demonstrated to be a useful modality of choice in the screening, diagnosis, and treatment of a PSA. The sonographic appearance of a PSA using gray-scale, color, and spectral Doppler can play a significant role in ruling out other diagnoses. A case study is presented of a dialysis-dependent patient who developed a PSA in his dialysis access site. Sonography played a key role in the diagnosis and follow-up for this specific case. Due to the risks involved with these patients, there is an essential need for sonographers to be competent in performing these examinations. Evaluation of the AVF to check for patency and a thorough assessment of the PSA are required. [ABSTRACT FROM AUTHOR]

Introduction: Pre-operative process optimization can expedite time-to-intervention and reduce overall health care costs. We hypothesized that the longest delay to hemodialysis (HD) access creation would be from pre-operative vessel mapping (mandatory in our practice), and that this would be correlated with increased catheter days., Methods: One hundred thirty patients (24 inpatients, 106 outpatients) who received initial hemodialysis (HD) access from 01/01/2017 to 12/31/2021, at the Veterans Affairs Puget Sound, Seattle, Washington, were identified. Median time differences between pre-operative events were compared between inpatients and outpatients using the Mann-Whitney U test. Outpatients were then stratified by time of catheter-based HD initiation (no catheter, pre-referral catheter, post-referral catheter) and compared. The impacts of mapping-related delays on catheter use were evaluated using regression., Results: Inpatients had shorter referral to access maturation times (125 days inpatient vs 146 days outpatient; p  = 0.03). This was driven by shorter referral to mapping (2 days inpatient vs 27 days outpatient; p  < 0.01) and mapping to pre-surgical evaluation (1-day inpatient vs 6 days outpatients; p  < 0.01) times. Pre-surgical evaluation to OR times represented the longest pre-operative delay in both groups (51 days inpatient vs 29 days outpatient; p  = 0.59). Among outpatients, tunneled catheter placement post-referral resulted in longer maturation times (74 days no catheter vs 67 days pre-referral vs 149 days post-referral; p  < 0.01) but not additional pre-operative delays. No trend existed between increased mapping times and catheter-based dialysis duration ( R 2  = 0.08)., Conclusion: Preoperative vein mapping contributed up to 21% of referral to maturation times but was not associated with increased tunneled catheter duration. While tunneled catheter placement impacted access maturation it did not cause additional pre-operative delays. Earlier referrals for access creation and reduction of outpatient wait-time from referral to OR and increased AV graft placement may minimize catheter days in our system thereby mitigating the added delays caused by pre-operative vein mapping., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: 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., Methods: 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., Results: 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., Conclusions: 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., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://qims.amegroups.com/article/view/10.21037/qims-23-1505/coif). The authors have no conflicts of interest to declare., (2024 Quantitative Imaging in Medicine and Surgery. All rights reserved.)

The effect of blood pump flow rate on the cardiac functions of hemodialysis patients with arteriovenous fistula (AVF) is largely unknown. This study aimed to investigate if blood pump flow rate (Qb) and AVF access flow rate (Qa) can affect the cardiac function of Chinese hemodialysis patients. A total of 72 patients undergoing AVF hemodialysis were included from March 2010 to June 2014 and dichotomized into the high‐ and low‐flow groups using the medians of Qb (220 mL/min) and Qa (1000 mL/min) as the cutoffs. The cardiac function parameters were measured by ultrasound dilution technique within the first (t + 30) and the last (t − 30) 30 min of dialysis. At t + 30, Qb‐high group had significantly higher systolic blood pressure (SBP) and mean arterial pressure (MAP) than Qb‐low group. At t − 30, Qb‐high group had higher SBP, diastolic blood pressure (DBP), and MAP than Qb‐low group. Qa‐high group had higher SBP, MAP, cardiac output (CO), cardiac index (CI), central blood volume (CBV), and lower peripheral resistance than Qa‐low group. Multiple linear regression showed that at t − 30, Qb was positively correlated with SBP and MAP. Qa was positively correlated with CO, CI, CBV, and PR but negatively correlated with heart rate. Although Qb > 220 mL/min and Qa >1000 mL/min would elevate some parameters, the means of SBP, DBP, MAP remain within the normal range, indicating that appropriate increase in blood pump flow rate has little effect on the cardiac function of hemodialysis patients. [ABSTRACT FROM AUTHOR]

Vascular access-induced ischemia remains a rare but significant complication of arteriovenous fistulas. Distal revascularization and interval ligation (DRIL) is one form of treatment. However, its collated efficacy through a systematic review is yet to be established. An electronic and systematic search of the literature in MEDLINE, Cumulative Index to Nursing and Allied Health Literature, Embase, and Cochrane Library from 1966 to 2017 in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was conducted. Quality assessment of the articles was performed using the Oxford Critical Appraisal Skills Programme, and the recommendation for practice was examined through the National Institute for Health and Care Excellence. Data of treated cases, success, time to ischemia, follow-up, age, sex, diabetes mellitus, fistula type, conduit type, and grade of ischemia were extracted and subjected to a pooled variance-weighted random-effects model. Twenty-two studies (n = 459 individuals) were subjected to DRIL. Time to ischemia was 196 days (interquartile range, 30-600 days). Ischemia grade 3/4 (52%) was the most common presentation. The overall success (grades 1-4) was 81% (95% confidence interval, 80.9%-82.5%) during a mean and median follow-up of 22.2 months (interquartile range, 1-60 months) and 18 months, respectively. The conduit of choice was the great saphenous vein (n = 300/459 [65%]), and bypass thrombosis was highest in the polytetrafluoroethylene group (n = 19/44 [43%]). DRIL with adequate long-term outcomes is an effective technique for the treatment of vascular access-induced ischemia. [ABSTRACT FROM AUTHOR]

Background: The incidence of chronic kidney disease (CKD) and end-stage kidney disease (ESKD) is increasing worldwide. Hemodialysis (HD) is the mainstay of renal replacement therapy for patients with ESKD. Risk factors associated with late arteriovenous fistula (AVF) failure in HD patients are poorly investigated. Therefore, the aim of this study was to identify factors associated with late AVF failure in HD patients., Methods: Patients with end-stage renal disease (ESRD) who underwent forearm or upper arm AVF angioplasty at Second Affiliated Hospital of Chongqing Medical University between September 2009 and August 2018 were included. Patients were followed up for 36 months. Baseline characteristics were collected using electronic medical records (EMRs). Variables associated with late AVF failure were identified using Cox proportional hazards models., Results: There were 137 patients (64% male, 36% female) included in this study, with 50 (36.5%) experiencing AVF failure. Univariable log-rank analysis showed that age, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), intact parathyroid hormone (iPTH), albumin (ALB), and AVF patency rate were significantly different between patients who did and did not experience AVF failure. Cox regression analysis showed that CRP [P=0.002, hazard ratio (HR) =2.719, 95% confidence interval (CI) for HR: 1.432-5.164], ESR (P=0.030, HR =2.431, 95% CI: 1.088-5.434), iPTH (P=0.013, HR =0.325, 95% CI: 0.133-0.793), and ALB (P=0.040, HR =0.539, 95% CI: 0.299-0.972) were independently associated with AVF failure. Kaplan-Meier survival analysis showed that the cumulative patency rates of AVF at 6, 12, 18, 24, 30, and 36 months were 84%, 74%, 69%, 64%, 64%, and 64%, respectively., Conclusions: CRP, ESR, iPTH, and ALB were associated with AVF failure and should be used as reference in clinical practice., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://tau.amegroups.com/article/view/10.21037/tau-23-431/coif). The authors have no conflicts of interest to declare., (2024 Translational Andrology and Urology. All rights reserved.)

Background: Radial arteriovenous fistula (AVF) post coronary artery intervention is rare.Methods and Conclusion: Here we describe an extremely rare case of radial AVF with retrograde filling through the deep palmar arch and presenting as early ischemic changes. [ABSTRACT FROM AUTHOR]

Highlights • We describe a one-sheath inverse method in vascular access intervention therapy (VAIVT) for hemodialysis patients. • It allows VAIVT to be performed using one sheath with one approach site in cases in which lesions are present on the upstream and downstream sides. • Because vascular access location is usually superficial, the technique can be utilized with relative ease. Abstract Introduction Vascular access intervention therapy (VAIVT) is an essential interventional therapy in the field of hemodialysis therapy that allows for the long-term vascular access functionality to be maintained. The venous approach is often performed in VAIVT for arteriovenous fistula. When lesions are present on the upstream and downstream sides from the approach site, it is likely that two sheaths will be inserted from two facing punctures. However, we have adopted a one-sheath inverse method using a guidewire in such cases. Case presentation We herein describe the steps of the technique that we have performed and report the successful treatment of a 77-year-old woman who developed arteriovenous fistula failure. Discussion To the best of our knowledge, the concrete and detailed technique has not been reported in the English literature to date. The merit of the technique is that it allows VAIVT to be performed using one sheath with one approach site in cases in which lesions are present on the upstream and downstream sides from the approach site. The other benefits include pain reduction, a shortened operation time, and reduced costs. Because vascular access location is usually superficial, the technique can be utilized with relative ease. Conclusion A one-sheath inverse method is useful. We hope that the technique will be more widely recognized, allowing the technique to be applied to more cases. [ABSTRACT FROM AUTHOR]

The classifier of support vector machine (SVM) learning for assessing the quality of arteriovenous fistulae (AVFs) in hemodialysis (HD) patients using a new photoplethysmography (PPG) sensor device is presented in this work. In clinical practice, there are two important indices for assessing the quality of AVF: the blood flow volume (BFV) and the degree of stenosis (DOS). In hospitals, the BFV and DOS of AVFs are nowadays assessed using an ultrasound Doppler machine, which is bulky, expensive, hard to use, and time consuming. In this study, a newly-developed PPG sensor device was utilized to provide patients and doctors with an inexpensive and small-sized solution for ubiquitous AVF assessment. The readout in this sensor was custom-designed to increase the signal-to-noise ratio (SNR) and reduce the environment interference via maximizing successfully the full dynamic range of measured PPG entering an analog−digital converter (ADC) and effective filtering techniques. With quality PPG measurements obtained, machine learning classifiers including SVM were adopted to assess AVF quality, where the input features are determined based on optical Beer−Lambert’s law and hemodynamic model, to ensure all the necessary features are considered. Finally, the clinical experiment results showed that the proposed PPG sensor device successfully achieved an accuracy of 87.84% based on SVM analysis in assessing DOS at AVF, while an accuracy of 88.61% was achieved for assessing BFV at AVF.

With the aging population and lifestyle changes, the number of hemodialysis (HD) patients increases year by year. The arteriovenous fistula (AVF) is the gold standard vascular access used to access the blood for HD treatment. Since the status of stenosis affects HD efficiency, current clinical practices usually use a Doppler ultrasound imaging system to assess the parameters of the stenosis, such as the degree of stenosis (DOS). Unfortunately, this is a very time-consuming task. Furthermore, it is difficult to stably maintain the ultrasound probe for a prolonged period to give doctors clearer or reproducible images. In this study, a robotic ultrasound system (RUS) with ultrasound sequential imaging analysis was designed to evaluate the DOS of the AVF. The sequential imaging analysis was capable of image smoothing and vessel boundary detection. It enabled clinicians to mark the thickness of the plaque for further processing. Finally, the system was used to reconstruct 3D models of fistulas and calculated the DOS for clinical assessment. We also designed a pressure sensingmodule attached to the ultrasound probe to prevent the probe from coming loose, vibrating, and exerting abnormal pressure on the skin. In the phantom test, the results showed that the error of the DOS that was calculated by RUS was less than 3%. The results of clinical trials obtained from ten patients show that the error between the RUS and clinicians' measurement was about 10% and had a highly linear correlation (R Square > 0.95). In addition, the reproducibility error was about 3% and could effectively save about 46% of the time during clinical examinations. [ABSTRACT FROM AUTHOR]

A novel blood-flow volume (BFV) sensor is presented for assessing quality of arteriovenous fistula in hemodialysis patients via noninvasive reflectance-type photoplethysmography (PPG). BFV is nowadays in clinic practices evaluated using an ultrasound Doppler monitor, which is expensive, bulky, and can only be operated by well-trained medical personnels. This study is devoted to develop a low-cost, small-sized, portable, and easy-to-use PPG sensor that is capable of continuous measurement of BFV. New designs of front-end analog circuits, signal processing, and an intelligent neural network calibration method are employed to finally achieve high correlation (R 2 = 0.7176), as opposed to the ultrasound Doppler monitor, with the root-mean-squared errors successfully controlled under 289 ml/min. [ABSTRACT FROM AUTHOR]

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A portable, wireless photoplethysomography (PPG) sensor for assessing arteriovenous fistula (AVF) by using class-weighted support vector machines (SVM) was presented in this study. Nowadays, in hospital, AVF are assessed by ultrasound Doppler machines, which are bulky, expensive, complicated-to-operate, and time-consuming. In this study, new PPG sensors were proposed and developed successfully to provide portable and inexpensive solutions for AVF assessments. To develop the sensor, at first, by combining the dimensionless number analysis and the optical Beer Lambert’s law, five input features were derived for the SVM classifier. In the next step, to increase the signal-noise ratio (SNR) of PPG signals, the front-end readout circuitries were designed to fully use the dynamic range of analog-digital converter (ADC) by controlling the circuitries gain and the light intensity of light emitted diode (LED). Digital signal processing algorithms were proposed next to check and fix signal anomalies. Finally, the class-weighted SVM classifiers employed five different kernel functions to assess AVF quality. The assessment results were provided to doctors for diagonosis and detemining ensuing proper treatments. The experimental results showed that the proposed PPG sensors successfully achieved an accuracy of 89.11% in assessing health of AVF and with a type II error of only 9.59%.

This paper proposes a noninvasive dual optical photoplethysmography (PPG) sensor to classify the degree of arteriovenous fistula (AVF) stenosis in hemodialysis (HD) patients. Dual PPG measurement node (DPMN) becomes the primary tool in this work for detecting abnormal narrowing vessel simultaneously in multi-beds monitoring patients. The mean and variance of Rising Slope (RS) and Falling Slope (FS) values between before and after HD treatment was used as the major features to classify AVF stenosis. Multilayer perceptron neural networks (MLPN) training algorithms are implemented for this analysis, which are the Levenberg-Marquardt, Scaled Conjugate Gradient, and Resilient Back-propagation, to identify the degree of HD patient stenosis. Eleven patients were recruited with mean age of 77 ± 10.8 years for analysis. The experimental results indicated that the variance of RS in the HD hand between before and after treatment was significant difference statistically to stenosis (p < 0.05). Levenberg-Marquardt algorithm (LMA) was significantly outperforms the other training algorithm. The classification accuracy and precision reached 94.82% and 92.22% respectively, thus this technique has a potential contribution to the early identification of stenosis for a medical diagnostic support system.