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Introduction: the external support device VasQ is intended to promote arteriovenous fistula (AVF) maturation by maintaining the optimal anastomotic angle in order to minimize blood flow disturbances around the anastomotic area. The aim of the study is to assess efficacy and safety of the VasQ device both in brachiocephalic and radiocephalic fistulae. Methods: a single institution prospective study was conducted with implantation of the VasQ device during AVF creation. Clinical and Doppler ultrasounds evaluations were performed at day-1, 1, 6, and 12 months for assessment of device-related adverse events, AVF maturation and patency. Moreover, volume flow rate and diameter of outflow vein were measured. A total of 16 patients were enrolled. Ten brachiocephalic and 6 radiocephalic AVFs were created with VasQ. Preoperatively cephalic vein diameter was 3.6 ± 0.9 mm. Results: our population included 13 male and 3 females patients, 9 end stage kidney disease in conservative therapy, 4 dialysis treated patients, and 3 transplanted patients; mean age was 74.0 ± 8.1 years; no severe device-related adverse events were observed. Primary patency at 1, 6, and 12 months was 100%, 87.5%, and 67.7%, respectively, while secondary patency was 100%, 100%, and 78.3%, respectively. Comparing brachiocephalic to radiocephalic AVFs no significant differences in patency rates were seen. Overall maturation rate was 94% (15/16). Mean vein diameter measured with Doppler ultrasound at postoperative day-1 and at 1, 6, and 12 months was 5.0 ± 1.0, 5.9 ± 0.9, 7.2 ± 1.6, and 7.9 ± 1.4 mm, respectively, with a mean flow rate at the brachial artery of 841 ± 176, 1052 ± 224, 1261 ± 490, and 1348 ± 477 ml/min, respectively. Conclusions: in our limited experience VasQ was safe, with high maturation and patency rates. Positive results suggest a potential benefit for VasQ in AVF.

Failure to mature and venous neointimal hyperplasia formation are the two major causes of hemodialysis arteriovenous fistula (AVF) vascular access failure. Percutaneous transluminal angioplasty (PTA) is the firstline treatment for both of these conditions, but, clinically, women have decreased patency rates compared with men. The hypothesis to be tested in the present study was that female mice after PTA of venous areas of higher intimal thickening have increased gene expression of transforming growth factor-β1 (TGF-β1) and TGF-β receptor 1 (TGFβ-R1) accompanied with histological changes of fibrosis compared with male mice. Seventeen male and eighteen female C57BL/6J mice were used in this study. Chronic kidney disease was induced by partial nephrectomy, and, 28 days later, an AVF was created to connect the left carotid artery to the right jugular vein. Two weeks later, the higher intimal thickening area was treated with PTA, and mice were euthanized 3 days later for gene expression analysis or 14 days later for histopathological analysis. Doppler ultrasound was performed weekly after AVF creation. At day 3, female AVF had significantly higher average gene expression of TGF-β1 and TGFβ-R1 compared with male AVF. At day 14, female outflow veins had a smaller venous diameter, lumen vessel area, decreased wall shear stress, lower average peak systolic velocity, and an increased neointima area-to-media area ratio. Moreover, female outflow veins showed a significant increase in α-smooth muscle actin and fibroblast-specific protein-1. There was a decrease in M1/M2 with an increase in CD68.

Creation of a hemodialysis arteriovenous fistula (AVF) causes aberrant vascular mechanics at and near the AVF anastomosis. When inadequately regulated, these aberrant mechanical factors may impede AVF lumen expansion to cause AVF maturation failure, a significant clinical problem with no effective treatments. The endothelial nitric oxide synthase (NOS3) system is crucial for vascular health and function, but its effect on AVF maturation has not been fully characterized. We hypothesize that NOS3 promotes AVF maturation by regulating local vascular mechanics following AVF creation. Here we report the first MRI-based fluid-structure interaction (FSI) study in a murine AVF model using three mouse strains: NOS3 overexpression (NOS3 OE) and knockout (NOS3−/−) on C57BL/6 background, with C57BL/6 as the wild-type control (NOS3+/+). When compared to NOS3+/+ and NOS3−/−, AVFs in the OE mice had larger lumen area. AVFs in the OE mice also had smoother blood flow streamlines, as well as lower blood shear stress at the wall, blood vorticity, inner wall circumferential stretch, and radial wall thinning at the anastomosis. Our results demonstrate that overexpression of NOS3 resulted in distinct hemodynamic and wall mechanical profiles associated with favorable AVF remodeling. Enhancing NOS3 expression may be a potential therapeutic approach for promoting AVF maturation.

Objective: To evaluate the role of preoperative peripheral blood neutrophil-to-lymphocyte ratio in predicting early arteriovenous fistula failure. The impact of postoperative neutrophil-to-lymphocyte ratio on arteriovenous fistula failure was also investigated. Methods: Medical records from 470 patients who underwent first-time arteriovenous fistula creation were studied. Demographic, clinical, and laboratory data were obtained. Receiver operating characteristic curves were constructed to determine the optimal cutoff values of preoperative and postoperative neutrophil-to-lymphocyte ratios for predicting early arteriovenous fistula failure. Univariate and multivariate analyses were performed to evaluate whether the neutrophil-to-lymphocyte ratio parameters were prognostic indicators for arteriovenous fistula failure. Results: Complete data from 396 patients were studied. The prevalence of early arteriovenous fistula failure was 30.6%. The optimal cutoff values of preoperative and postoperative neutrophil-to-lymphocyte ratios for predicting early arteriovenous fistula failure were 2.7 (82.6% sensitivity and 52.0% specificity) and 2.9 (78.5% sensitivity and 73.1% specificity), respectively. By univariate and multivariate analyses, high preoperative and postoperative neutrophil-to-lymphocyte ratios were significantly associated with early arteriovenous fistula failure. The adjusted odds ratios were 5.46 (95% confidence interval: 3.15–9.48) and 7.19 (95% confidence interval: 4.12–12.55), respectively. Conclusions: High preoperative and postoperative neutrophil-to-lymphocyte ratios significantly predict early arteriovenous fistula failure.

Background: Cardiovascular diseases are the most common cause of high mortality in hemodialysis patients. These patients undergoing maintenance hemodialysis through arteriovenous fistula (AVF) develop both structural and functional cardiovascular abnormalities. Aim of the review: Highlight the potential influence of AVFson cardiac function, which may contribute to its timely detection and allow measures to be taken that might prevent its serious complications. Methods: We have searched literatures in American National Center for Biotechnology Information (NCBI), PubMed, Google scholar, Egyptian bank of knowledge and science direct. Conclusion: Patients with AVFs should be followed regularly with echocardiographic studies to detect any cardiac complications as early as possible.

To determine the efficacy of a percutaneous sharp needle recanalization technique for the treatment of peripheral hemodialysis arteriovenous fistula (AVF) occlusion. This study included 13 patients (14 procedures) between May 2010 and February 2020 with non-thrombotic AVF occlusion wherein guidewire passage through the occluded segment had failed. We successfully passed the guidewire through the occluded segment using a sharp needle recanalization technique with Chiba or Colapinto needles, under ultrasound or fluoroscopic guidance. The type of AVF, site and length of occlusion, technical success, complications, and long-term patency were analyzed. Technical success was achieved in 12 (85.7%) out of 14 procedures. The procedure failed in two patients due to the poor angle of approach in the axillary area and diffuse severe stenosis in the draining cephalic vein. In eight procedures, sharp needle recanalization was performed under ultrasound guidance, while the other six procedures were performed under fluoroscopic guidance. Chiba and Colapinto needles were used in five and nine procedures, respectively. The mean length of occlusion was 2.7 cm (range 1.8–4.2 cm). There was one case of mild complication, that is, mild contrast extravasation, which was treated by stent deployment. The post-intervention primary patency rates at 6 months, 1 year, and 2 years were 81.8%, 36.4%, and 18.2%, respectively. The results of this limited series suggest that the sharp needle recanalization technique is a simple and effective method for the treatment of peripheral non-thrombotic AVF occlusion.

Background Women have decreased hemodialysis arteriovenous fistula (AVF) maturation and patency rates. We determined the mechanisms responsible for the sex‐specific differences in AVF maturation and stenosis formation by performing whole transcriptome RNA sequencing with differential gene expression and pathway analysis, histopathological changes, and in vitro cell culture experiments from male and female smooth muscle cells. Methods and Results Mice with chronic kidney disease and AVF were used. Outflow veins were evaluated for gene expression, histomorphometric analysis, Doppler ultrasound, immunohistologic analysis, and fibrosis. Primary vascular smooth muscle cells were collected from female and male aorta vessels. In female AVFs, RNA sequencing with real‐time polymerase chain reaction analysis demonstrated a significant decrease in the average gene expression of BMP7 (bone morphogenetic protein 7) and downstream IL17Rb (interleukin 17 receptor b) , with increased transforming growth factor‐β1 ( Tgf‐β1) and transforming growth factor‐β receptor 1 ( Tgfβ‐r1) . There was decreased peak velocity, negative vascular remodeling with higher venous fibrosis and an increase in synthetic vascular smooth muscle cell phenotype, decrease in proliferation, and increase in apoptosis in female outflow veins at day 28. In vitro primary vascular smooth muscle cell experiments performed under hypoxic conditions demonstrated, in female compared with male cells, that there was increased gene expression of Tgf‐β1 , Tgfβ‐r1 , and Col1 with increased migration. Conclusions In female AVFs, there is decreased gene expression of BMP7 and IL17Rb with increased Tgf‐β1 and Tgfβ‐r1 , and the cellular and vascular differences result in venous fibrosis with negative vascular remodeling.

Background: Kidney allograft resistive index (RI) is prognostic for graft and recipient survivals. Recipient hemodynamics could influence RI. In particular, dialysis arteriovenous fistula (AVF) has been involved in heart function changes, reversible after AVF ligation. Knowledge about AVF and RI is lacking. In this study, we prospectively evaluated RI changes after AVF ligation in kidney transplanted patients. Methods: We enrolled 22 stable transplanted patients. Mean RI was measured before AVF ligation (T0), 18 to 24 h (T1) and 6 months (T6) after surgery; mean blood pressure (mBP), heart rate (HR), serum creatinine (sCr), estimated glomerular filtration rate (eGFR), 24 h proteinuria (24 h-P), immunosuppressive drug blood levels (IS) and antihypertensive drugs were also recorded. Results: AVF ligation was performed 3.1 years (IQR: 2.1–3.8) after transplantation. Median AVF flow (Qa) was 1868 mL/min (IQR: 1538–2712) and 8 AVF were classified as high flow (Qa ≥ 2 L/min). At baseline, median sCr was 1.32 mg/dL (IQR: 1.04–1.76) and median eGFR was 57.1 mL/min. Median RI was 0.71 at T0, 0.69 at T1, 0.66 at T6. RI reduction at T1 and T6 was statistically significant (p < 0.05 and p < 0.001 respectively); in particular, 90.4% of patients had persistently improved values at T6. Furthermore, mBP increased while HR decreased. These changes were independent from sCr, 24 h-P, IS, antihypertensive drugs number, Qa and AVF type. Conclusions: AVF ligation improves kidney allograft RI; it may reflect better kidney perfusion.

To assess the causes of immature hemodialysis arteriovenous fistula and the outcome of endovascular salvage.The outcome of 207 endovascular salvage procedures in 139 patients after the first successful cannulation was analyzed retrospectively from January 2011 to December 2017 in the Catholic University of Korea, Seoul St. Mary's Hospital.Of the 139 patients aged 62 ± 13 years, 45% were women, 59% had diabetes, and 71% were maintained on hemodialysis using central venous catheters. Mean interval between arteriovenous fistula creation and referral to angiography was 87 ± 63 days. While inflow stenosis (54.4%) was the most common cause of immature forearm fistulas (n = 76), both inflow (38.6%) and mixed stenosis (35.1%) were the main causes of immature upper arm fistulas (n = 63). Endovascular salvage procedures included percutaneous transluminal angioplasty (n = 174) and accessory vein obliteration (n = 30). The overall technical and clinical success rates were 97% and 93.4%, respectively. Mean interval between endovascular procedure and the first successful cannulation of the fistula was 28 ± 35 days. At 3, 6, and 12 months following the first successful cannulation, the primary patency rates were 81%, 69.5%, and 57.6%, respectively, and the secondary patency rates were 97.2%, 96%, and 94.8%, respectively. Mixed stenosis was the only determinant of secondary patency rate of immature arteriovenous fistula (hazard ratio = 6.334, confidence interval = 1.364-29.423,Immature arteriovenous fistulas can be successfully salvaged by aggressive and timely endovascular intervention. Mixed stenosis is associated with poor access outcomes.

Lipectomy is an acceptable method of cephalic vein superficialization in hemodialysis arteriovenous fistula. However, limiting it to be a secondary procedure may prolong time between fistula creation and successful cannulation posing more risk of central venous catheter use.The aim of this study is to evaluate primary surgical lipectomy performed at the time of arteriovenous fistula creation in comparison with secondary lipectomy.Between June 2015 and January 2017, 59 adult end-stage renal disease patients were allocated non-randomly to group I, 35 patients had arteriovenous fistula with primary lipectomy of forearm or arm deep cephalic veins, and group II, 24 patients who had secondary lipectomy of deep forearm or arm cephalic veins after primary arteriovenous fistula.Mean body mass index was 28.2 ± 3.2 kg/mLipectomy is a minimally invasive procedure carried out through small incision(s). Primary and secondary lipectomy procedures have few complications, and acceptable technical and clinical success rates. Primary lipectomy has the advantage to hasten fistula use and diminish central venous catheter dependency.

Purpose: The AngioJet Hemolytic Thrombectomy Device “AngioJet” (Boston Scientific, Malborough, MA, USA) is a rheolytic thrombectomy device that can be used in the treatment of hemodialysis arteriovenous fistula and graft thrombosis. We aim to appraise the current evidence on AngioJet thrombectomy in hemodialysis vascular access thrombosis, and to determine its safety, including complications and efficacy. Materials and methods: An electronic literature search was performed on the MEDLINE and Embase databases. References of retrieved articles were also reviewed. Articles using AngioJet for the treatment of arteriovenous fistula or graft were included. Patients less than 18 years old, non-English articles, single case reports, small case series (Results: A total of 688 articles were initially evaluated and 10 articles fulfilled the inclusion criteria, which included 836 patients with 431 grafts and 234 fistulas. Results were heterogeneously reported. The adjusted mean primary patency rates for 1, 3, 6, and 12 months were 64.6%, 43.8%, 42.5%, and 30.5%, respectively; adjusted mean secondary patency rates for 3, 6, and 12 months were 76.5%, 75.1%, and 74.5%, and assisted primary patency rates were 61.9%, 47.3%, and 35.3%, respectively. There were 126 complications, most were minor. There were seven deaths, but were unable to be attributable to the AngioJet. Conclusion: The AngioJet is an effective and safe treatment option for thrombosed fistulas and grafts. However, the quality of the current evidence is poor. Further research with prospective randomized controlled trials using standardized data reporting methods is needed to prove its safety and efficacy.

Purpose. The aim of this study was to evaluate the flow volume and resistive index parameters of the brachial artery in the functioning and dysfunctioning radiocephalic and brachiocephalic hemodialysis arteriovenous fistula (AVF).Methods. 82 patients were distributed into three groups according to their hemodialysis function - as normal function, decreased pump flow and increased venous pressure. Flow volumes and resistive indexes (RI) of the brachial artery of radiocephalic and brachiocephalic AVFs were measured by Doppler ultrasound. Flow parameters of the groups were compared. Results. A statistically significant difference was found between the normal and decreased pump flow groups in terms of flow volume and resistive index values. 770 ml/min flow volume of the brachial artery has a 94% sensitivity and 84% specificity and 0.52 value of RI has an 89% sensitivity and 88% specificity in the the differentiation of normal and decreased pump flow groups.Conclusion. Doppler parameters of the brachial artery such as flow volume and RI can provide valuable information about AVF function.

Introduction Brescia-Cimino radiocephalic arteriovenous fistula (AVF) remains the first-choice vascular access procedure for patients in need of long-term hemodialysis. The average life expectancy of patients receiving hemodialysis has increased in recent years and many patients now live longer and require secondary or tertiary procedures. Elbow fistulas should only rarely be constructed as primary fistulas. The aim of the surgeon must be not only to achieve a functioning fistula, but to avoid possible complications other than failure to mature (FTM), like distal ischemia and cardiac failure and to save the vessels as much as possible for future procedures Background Both arterial and venous anatomy of the elbow and upper arm have significant variations. The surgeon must be aware of these variations during the operation, and try not to harm the vasculature of the extremity while trying to construct a functioning fistula. The main advantages of elbow fistulas are the opportunity to have multiple outflows, preservation of the major veins in their original place with no dissection and giving no harm to them, and having a longer outflow tract for cannulation. Conclusions In the elbow, beginning to construct an AVF with the perforating vein is the most advantageous. If the perforating vein is not available or has been used before, median cubital vein, its branches, median antecubital vein or other available nearby veins may be used depending on the anatomy. Perforating vein should be ligated if any other elbow vein is used to prevent flow to deep veins.

Background: Smart Flow is an innovative tool available on the Carestream Touch Prime Ultrasound machines, which provides automated blood flow measurement and shows the vectors that form the blood flow in the vessel. We compared the use of Smart Flow with traditional Duplex Doppler Ultrasound to evaluate blood flow of arteriovenous fistulas in prevalent hemodialysis patients. Methods: A total of 31 chronic patients on hemodialysis were enrolled. Blood flow was measured on the brachial artery with Smart Flow and duplex Doppler ultrasound. In a subset of 26 patients, a video of the juxta-anastomotic efferent vein was recorded and analyzed to calculate an index of flow turbulence. Results: We enrolled 21 males and 10 females aged 68.52 ± 11.64 years at the time of evaluation with an average arteriovenous fistulas vintage of 50.23 ± 47.42 months and followed them up for 18.03 ± 5.18 months. Smart Flow and Duplex Doppler Ultrasound blood flow measurements positively correlated (p Conclusion: Smart Flow is reliable, reproducible, and faster than traditional duplex ultrasound. However, the additional information given by the Smart Flow technique does not seem to add any further benefits in terms of prediction of the access failure.

orhan, gokcen/0000-0003-4809-6139, WOS: 000496286700035, PubMed: 31547762, [No abstract available], Faculty of Medicine Vajira Hospital, Navamindradhiraj University, The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: this article received grant from the Faculty of Medicine Vajira Hospital, Navamindradhiraj University.

Background: According to KDOQI guidelines, the lower limit of arteriovenous fistula blood flow accounting for 600 ml / min. We have observed that this limit was not enough, at least for our patients. The aim of this work was to prove the hypothesis that this limit must be higher for performing adequate dialysis. Patiemts and methods : Fifty patients on prevalent hemodialysis were included in this study. They were divided into 3 groups; group I: 12 patients formed low flow group, group II: 18 patients formed moderate flow group , and group III: 20 patients formed high flow group . Complete physical examination including clinical fistula examination for patency , were performed for all patients . Laboratory tests performed for all patients included :urea reduction ratio (URR %) , serum calcium ,serum phosphorus , calcium – phosphorus product , serum albumin , hemoglobin , serum Iron , serum ferritin ,TIBC , Transferrin saturation (TSAT %) , Kt / V (number used to quantify hemodialysis treatment adequacy), serum creatinine , together with blood urea before and after session . Fistula blood flow and static venous pressure were determined by Doppler ultrasound . Fistulogram was performed to confirm the fistula stenosis site , whenever detected by Doppler . Results: Mineral bone profile markers , Iron profile markers , together with malnutrition – inflammation complex indicators , were all in favour of moderate and high flow groups , mainly the moderate flow group II due to the presence of much less complications than the other groups . Conclusion: We have to try to perform arteriovenous fistulae for ESRD patients needing regular dialysis , in such a way that fistula blood flow is above 800 ml / min , and it is better to be within the range of 801 – 1600 ml / min .

Objective: Percutaneous transluminal balloon angioplasty (PTA) is recommended as the first choice to treat stenosis of Brescia-Cimino arteriovenous fistulas (B-C AVFs). The ability to predict which B-C AVFs are at risk for recurrent stenosis post-PTA would allow closer monitoring of patients, and possibly result in surgical intervention rather than repeat PTA. The purpose of this study was to identify predictive factors of primary patency after PTA in B-C AVFs. Methods: Patients diagnosed with B-C AVF primary stenosis and treated by PTA between November 2013 and March 2018 were included in the study. Patient and stenotic lesion characteristics and PTA procedure factors were included in the analysis. The Kaplan–Meier method was used to analyze the primary patency rate. Cox proportional hazard regression analysis was used to identify factors predictive of decreased primary patency. Results: 74 patients (35 males, 39 females) with a mean age of 61.68 ± 11.44 years (range, 36–84 years) were included in the study. The mean B-C AVF age was 16.34 ± 12.93 months (range, 2–84 months), and the median primary patency time was 7.79 ± 0.48 months. Cox proportional hazard regression analysis revealed stenosis location at the inflow artery [hazard ratio (HR)=3.83, 95% confidence interval (CI): 1.46–10.09] or anastomosis (HR = 1.90, 95% CI: 1.09–3.32), dilation >2 times during PTA (HR = 2.30, 95% CI: 1.22–4.34), and residual stenosis >30% (HR = 2.42, 95% CI: 1.26–4.63) were significantly associated with decreased patency. Conclusion: In conclusion, the primary patency rate of PTA for B-C AVF dysfunction is reduced by dilation >2 times, residual stenosis >30%, and stenosis located at the inflow artery or anastomosis. These results may help in tailoring surveillance programs, multiple PTA, or a proximal re-anastomosis surgery in patients with AVF dysfunction. Advances in knowledge: A number of studies have been conducted to examine the predictors of primary patency after PTA, however, no definitive conclusions have been reached. Our study revealed that stenosis location at the inflow artery or anastomosis, dilation >2 times during PTA, and residual stenosis >30% were the predictors of primary patency after PTA, which may help in tailoring surveillance programs, multiple PTA, or a proximal re-anastomosis surgery in patients with arteriovenous fistulas dysfunction.

Introduction: Several histologic features have been identified in the upper-extremity arteries and veins of patients with advanced chronic kidney disease, which may affect arteriovenous fistula maturation. However, it is unclear whether these chronic kidney disease vascular features are abnormal. Methods: We obtained upper-extremity arterial and venous specimens from 125 advanced chronic kidney disease patients undergoing arteriovenous fistula creation and from 15 control subjects. We quantified medial fibrosis, micro-calcification, and intimal hyperplasia with appropriate histology stains. We characterized medial collagen fiber configuration in second-harmonic-generation microscopy images for the fiber anisotropy index and the dominant fiber direction. Results: The advanced chronic kidney disease patients were significantly younger than control subjects (53 ± 14 years vs 76 ± 11 years, p Conclusion: Advanced chronic kidney disease is associated with several abnormalities in vascular histology and collagen fiber configuration. Future research is needed to investigate whether these abnormalities affect the maturation outcomes of arteriovenous fistulas.

OBJECTIVE: To compare blood flow rates measured by Doppler ultrasonography (DUS) and phase-contrast magnetic resonance imaging (PC-MRI) in patients having a hemodialysis arteriovenous fistula (AVF) and to identify scenarios in which there was significant discordance between these two approaches. METHODS: Blood flow rates in the proximal artery and draining vein of newly created upper-extremity AVFs were measured and compared using DUS and PC-MRI at 1 day, 6 weeks, and 6 months postoperatively. RESULTS: Blood flow rate in the proximal artery measured by DUS (1155 ± 907 mL/min, mean ± standard deviation) and by MRI (1170 ± 657 mL/min) were not statistically different (P = .812), based on 78 data pairs from 49 patients. Draining vein DUS-flow (1277 ± 995 mL/min) and MRI-flow (1130 ± 655 mL/min) were also not statistically different (P = .071), based on 64 data pairs. In both proximal artery and draining vein, the two methods substantially agreed with each other (Cohen’s kappa: proximal artery = 0.66, draining vein = 0.67) when flow rates were put into four clinically relevant categories (lower than 300, 300-599, 600-1499, and 1500 mL/min or higher). The Bland-Altman analyses of DUS- and MRI-flow identified six and four outliers for proximal artery and draining vein, respectively. Seven outliers had higher DUS- than MRI-flow, with all DUS scan sites having a large lumen and/or significant local curvature; the other three had lower DUS-flow, partly due to an underestimation of lumen diameter by DUS. CONCLUSIONS: DUS- and MRI-flow rates are generally comparable in both proximal artery and draining vein. When using DUS for flow measurements, careful attention to accurate lumen diameter measurements is needed and scan sites with marked curvature should be avoided. Our result may improve the accuracy of DUS-measured AVF blood flow rate.

Proximalization of the arterial inflow is performed to address ischemic steal syndrome secondary to a functioning hemodialysis arteriovenous fistula. This procedure allows for preservation of the fistula without having to ligate the native artery at the fistula side as done in the DRIL procedure. This chapter describes indications, essential steps, variations, and complications of this procedure. It provides a detailed template operative note for the procedure.

To compare: (i) rate of arteriovenous fistula (AVF) interventions in both incident and prevalent end-stage kidney disease patients; (ii) their associated costs; and (iii) intervention-free survival between patients with surgical hemodialysis arteriovenous fistula (SAVF) versus those with an endovascularly created fistula (endoAVF).Data from the United States Renal Data System (USRDS) were abstracted to determine the rate of AVF interventions performed in the first year and associated costs (based on Medicare payment rates) for SAVFs created from 2011 to 2013 in the incident and prevalent patient cohorts. Comparative data for endoAVF were obtained from the Novel Endovascular Access Trial (NEAT). Event rates, intervention-free survival, and costs were compared between endoAVF and SAVF cohorts after 1:1 propensity score (PS) matching.In the matched incident patients, the event rate was 0.74 per patient-year (PY) for endoAVF versus 7.22/PY for SAVF (P.0001), with a difference in expenditures of $16,494. Similarly, in matched prevalent patients the event rate was 0.46/PY for endoAVF vs 4.10/PY for SAVF (P.0001), resulting in a cost difference of $13,389. Time-to-event analysis showed that at 1 year, 70% of endoAVF patients experienced freedom from intervention versus only 18% of SAVF patients for incident patients; these numbers were 62% and 18% for endoAVF and SAVF prevalent patients, respectively (P.0001 for both).Both incident and prevalent patients with endoAVF required fewer interventions and had lower costs within the first year compared with matched patients with SAVF.

Ultrasound is the initial imaging modality of choice when evaluating the upper extremity venous system. When sonographic findings are equivocal or nondiagnostic, particularly in evaluating the central deep veins, MR venography or catheter venography correlation may be helpful. Ultrasound provides an accurate, rapid, low-cost, portable, noninvasive method for screening, mapping, and surveillance of the upper extremity venous system.

Aneurysmal degeneration of a hemodialysis arteriovenous fistula (AVF) is common; however, distal digital embolization from an AVF is extremely rare. Even though the ultimate fate of all arteriovenous hemodialysis access is thrombosis with minimal consequences, dislodgement of thrombus at the proximal anastomosis could lead to ischemia of the distal arterial circulation. We here present a case of a renal transplant patient with a thrombosed aneurysmal AVF who presented with acute digital ischemia successfully treated with combination catheter-directed thrombolysis and open repair. No similar report was found describing this entity treated with this approach.

Both physical examination (PE) and intra-access pressure (IAP) measurements have been used in the identification of stenosis in an arteriovenous access. The aim of this study was to evaluate the accuracy of PE and IAP in the diagnosis of arteriovenous fistula (AVF) stenosis. A total of 84 patients were enrolled in the study (54% men, mean age of 50.7 +/- 12.7 years and mean AVF patency of 24.9 +/- 7.8 months, 52% radiocephalic). Abnormalities of pulse and thrill were used as the diagnostic tools for the detection of stenosis using the physical examination. For IAP, stenosis was suspected when the ratio between IAP at the arterial puncture site and the mean blood pressure was 0.43. The diagnosis of stenosis was confirmed by Doppler ultrasound (DU). Sensitivity (S), specificity (SP), positive predictive value (PPV), negative predictive value (PNV), and accuracy were calculated for the two early detection tests. According to DU, 50 (59%) AVF were considered positive for the presence of stenosis. Fifty-six (66%) AVF were considered positive for the presence of stenosis by PE and 34 (40%) by IAP. S, SP, PPV, and NPV for PE and IAP were 96%, 76%, 86%, and 93% and 60%, 88%, 88%, and 60%, respectively. The accuracy for PE and IAP was 88% and 71%, respectively. PE proved to be an accurate method for the diagnosis of stenosis and should be part of all surveillance protocols of stenosis detection in AVF.

Introduction Brescia-Cimino radiocephalic arteriovenous fistula (AVF) remains the first choice vascular access procedure for patients in need of long-term hemodialysis. Brachiocephalic fistulas are considered as a secondary option in almost all published guidelines. Recently in many reports, elbow and upper arm fistulas are recommended to be used as primary fistulas especially in elderly, diabetic, hypertensive patients. Elbow fistulas (brachiocephalic and brachiobasilic) should only rarely be constructed as primary fistulas. Forearm AVFs should be tried first to give a chance to the patient, because it is not the maturation-patency rates per se but also lowering the complication rates and saving the vessels for future use are equally important. Background The average life expectancy of patients receiving hemodialysis has increased in recent years and many patients now live longer and require secondary or tertiary procedures. Conclusions When forearm fistulas have failed, brachiocephalic AVF is usually preferred first, because of cephalic vein's appropriate anatomy for easy cannulation and ease of the operation. Operative procedure is less invasive compared to brachiobasilic AVF, therefore BC should be the procedure of choice when both veins are available.

OBJECTIVE: to determine the accuracy of Doppler ultrasonography (USD) for hemodialysis arteriovenous fistula (AVF) maturity.METHODS: we included patients with no prior AVF. Each patient underwent two USD examinations. After initiation of hemodialysis, we followed the patients during the first month of the access use and verified its adequacy to hemodialysis sessions. At statistical analysis we measured specificity, sensitivity, accuracy, ROC curve (Receiver operator characteristic) curve, TG-ROC (Two graph - receiver operator characteristic) and logistic regression.RESULTS: we included 76 patients, of which 51 completed the study. They formed two groups, those who have had good adequacy for hemodialysis (45) and those who had not (6). The average flow volume (FV) and the average draining vein diameter (DVD) of each group were, respectively: 940mL/min (95% CI: 829-1052) and 325mL/min (95% CI: 140-510); and 0.48cm (95% CI: 0.45-0.52) and 0.33cm (95% CI: 0.27-0.40). The area under the ROC curve of FV and DVD were 0.926 and 0.766, respectively.CONCLUSION: the accuracy of the measured volume flow measured at the draining vein to evaluate maturation of hemodialysis arteriovenous fistula was 85%.

The coexistence of aortic valve stenosis (AS) with hemodialysis arteriovenous (AV) fistula complicates the assessment of the severity of valvular disease. We describe the physiological changes in stenotic indices which occur following manual compression of the AV fistula. The manual compression of the AV fistula is capable of inducing significant alterations in transvalvular flow rates and valvulo-arterial impedance that translates into important changes in aortic valve hemodynamics and grading of stenosis severity.

慢性血液透析患者14例について, シャント血流不足や静脈圧上昇などのシャント機能不全をきたした血液透析用動静脈瘻をBモード・カラードップラー複合法を用いて評価した. シャント機能不全の原因として静脈拡張不全や血栓形成の存在を認めた. また静脈壁の解離像や静脈弁などの内部構造のほか, カラードップラー表示により, 深部静脈への側副血行路も確認できた. 血液透析用動静脈瘻の面積狭窄率は狭窄部と前後の非狭窄部の血流速度を計測することで算定し得た. Bモード・カラードップラー複合法は血管の内部構造や深部静脈への流入などの立体的観察, 面積狭窄率の血流速度による算定などが可能であり, 血液透析用動静脈瘻の機能不全の診断に有用と考えられた.

There is no accepted policy for preserving or ligating arteriovenous fistula (AVF) after successful kidney transplantation. The aim of this study was to compare kidney graft function and survival between patients with a functional AVF at 1 year after-transplantation with those having a nonfunctional AVF. This historical cohort study included 311 kidney transplant recipients between January 2000 and December 2008 with a functional AVF at the time of transplantation. Patients were divided into 2 groups according to functional status of AVF at 1 year after transplantation. Graft function was assessed at 1 year by serum creatinine and estimated glomerular filtration rate (eGFR) using the 4-variable Modification of Diet in Renal Disease formula. Kaplan-Meier and Cox proportional hazards analyses were used to assess the relationship between the functional status of the AVF and graft survival. The 311 recipients had a mean age of 47 ± 11 years (range, 14 to 70) with 188 (60.5%) males. Patients with functional AVF at 1 year (n = 239) showed higher serum creatinine and lower eGFR values than those with nonfunctional AVF (n = 72): namely 110 ± 38 μmol/L and 69 ± 21 mL/min/1.73 m(2) versus 99 ± 30 μmol/L and 74 ± 19 mL/min/1.73 m(2), respectively (P < .05). Persistence of a functional AVF at 1 year after transplantation was associated with a greater incidence of eGFR

After the pioneer observations by Hunter more than two centuries ago, recent reports have expanded our knowledge about the occurrence and pathophysiology of arterial abnormalities associated with long-lasting hemodialysis arteriovenous fistula (AVF) after its closure. Observed abnormalities include arterial dilatation and aneurysm formation proximal to the site of the repaired AVF. We describe here a patient who developed, after long-lasting hemodialysis AVF, a pan-arterial dilatation with a large brachial artery aneurysm, which was successfully treated with a polytetrafluoroethylene bypass graft.

To compare various objective ultrasonographic (US) criteria for native arteriovenous fistula (AVF) maturation with subsequent fistula outcomes and clinical evaluation by experienced dialysis nurses.US fistula evaluation results were analyzed retrospectively in 69 patients within 4 months after AVF placement; adequacy for dialysis was known in 54. Measurements included minimum venous diameter and blood flow rate. Experienced dialysis nurses examined 30 fistulas clinically. Predictors of fistula adequacy were analyzed with univariate and multivariate logistic regression. Mean fistula diameters and blood flow rates were compared by using analysis of variance or unpaired Student t tests.Fistula adequacy for dialysis doubled if the minimum venous diameter was 0.4 cm or greater (89% [24 of 27]) versus less than 0.4 cm (44% [12 of 27]; P.001). Fistula adequacy for dialysis was nearly doubled if flow volume was 500 mL/min or greater (84% [26 of 31]) versus less than 500 mL/min (43% [nine of 21]; P =.002). Combining venous diameter and flow volume increased fistula adequacy predictive value: minimum venous diameter of 0.4 cm or greater and flow volume of 500 mL/min or greater (95% [19 of 20]) versus neither criterion met (33% [five of 15]; P =.002). Women were less likely to have an adequate fistula diameter of 0.4 cm or greater: 40% (12 of 30) of women versus 69% (27 of 39; P =.015) of men. No significant differences in blood flow or minimum venous diameter were found during 2-4 postoperative months. Experienced dialysis nurses' accuracy in predicting eventual fistula maturity was 80% (24 of 30).US measurements of AVF at 2-4 months in patients undergoing hemodialysis are highly predictive of fistula maturation and adequacy for dialysis.

To the Editor: We wish to follow up the report of a new rat tail model of the hemodialysis arteriovenous fistula (AVF).1 Such models are potentially important because maturation failure of AVFs is a major unsolved problem. Lin et al.1 reported 5/5 successful operations in which the lateral vein was anastomosed end-to-side to the ventral artery. We report our experience in creating 27 such AVFs.

A retrospective analysis was performed to investigate the effectivity of snuff box and radial styloid arteriovenous fistula as access procedures for mainte nance hemodialysis. Taken into account that men were considered significantly more often suit able to construct a snuffbox fistula, we found no differences in effectivity be tween the two locations in arterialization of forearm veins and suitability for hemodialysis treatment.