Autogenous radial-cephalic direct wrist arteriovenous fistula (RC-AVF) in the non-dominant arm is the gold standard for dialysis vascular access. However, the RC-AVF non-maturation rate is significant (≃ 40%) due to an increasingly elderly and comorbid population incidence. A detailed identification of the biological cascade underlying arteriovenous fistula (AVF) maturation could be the key to clinical research aimed at identify the group of patients at risk of primary AVF failure. Currently, careful post-operative monitoring remains the most crucial aspect to overcome the problem of impaired maturation. Up to 80% of patients with immature RC-AVF have problems potentially solvable with early endovascular or surgical correction. Physical examination by experienced practitioners in conjunction with duplex ultrasound examination (DUS) can identify physical signs of non-maturation, understand the underlying cause, and drive for a tailored early planning to treat the complication. New approaches for the early assessment of AVF maturation are under study. Techniques to promote RC-AVF maturation performed through the administration of pre-or peri-operative drugs have missed up to now to prove an efficacy in improving fistula success. The new techniques tested after surgery appear to hold future promise for improving fistula maturation.

Introduction: Outflow stenosis is a frequent complication of vascular access for hemodialysis. It may cause increased pressure within the angioaccess along with reduced blood flow. Elective treatment is percutaneous transluminal angioplasty; however, when a long occlusion (>2 cm) occurs, success and mid-term patency of endovascular treatment are uncertain. We describe a case series of patients with long occlusion of elbow outflow complicating an otherwise excellent forearm arteriovenous fistula, treated by a bypass across the elbow through cubital vein transposition. Patients and methods: Six consecutive patients have been treated between 2015 and 2017; all were referred because of either low flow, increased venous pressure, excessive bleeding time, or recirculation and were examined by duplex ultrasound. A total of 83% of patients showed associated thrombosis within the access. All procedures were performed under loco-regional anesthesia and preventive hemostasis. Surgical thrombectomy was also performed when needed. Results: Immediate success was obtained in all but two patients converted in veno-venous polytetrafluoroethylene bypass. Post-operative blood flow increased from 316 to 878 mL/min. All patients were dialyzed through the forearm access immediately the day after surgery, without the need for central vein catheter. Overall, 75% of patients needed a percutaneous transluminal angioplasty of the veno-venous anastomosis within 6 months. Primary and secondary patency at 12 and 24 months were 25%–0% and 100%–100%, respectively. Conclusion: Outflow reconstruction through the elbow bypass by cubital vein transposition is a valuable resource to rescue radiocephalic arteriovenous fistula complicated by outflow obstruction, avoiding the use of an interim central vein catheter. Endovascular treatment is vital to maintain functional patency in the mid- and long term.

Background: Arteriovenous fistula (AVF) is the preferred angioaccess for haemodialysis but suffers from a high stenosis rate, juxta-anastomotic stenosis (JAS) being the most frequent. Percutaneous transluminal angioplasty (PTA) of JAS would have some advantage (such as mini-invasive and vein sparing treatment), but higher recurrence rate is observed as compared to surgery. We report results of juxta anastomotic stenosis PTA using the ‘double guide technique’ (DGT) as described by Turmel-Rodrigues, in a selected cohort from our Vascular Access Centre. Patients and methods: From January to June 2018, 25 consecutive patients were treated by DGT. By means of retrograde access through the outflow vein by a 6 F introducer, two guide wires were navigated: one into proximal radial artery (GW1), the other into distal artery (GW2). GW2 was used to dilate juxta-anastomotic vein and anastomotic area with 6 mm high-pressure balloon, while by GW1 juxta-anastomotic artery was dilated with 4 mm semi-compliant balloon. Mean diameter of balloons were 6.7 and 4.1 mm for venous and arterial tract dilatation. Follow up was carried out up to 12 months. Prospectively collected data were analysed retrospectively. Results: One-year primary and secondary patency was 52% and 95% respectively. Recurrence rate was 0.56 procedure/pt/year. Mean access blood flow at 12 months was 830 ml/min. Conclusion: Double Guidewire Technique is an effective and minimally invasive procedure. By avoiding under dilation of JAS the recurrence rate resulted quite satisfactorily in our population.

Background and Aims Juxta-anastomotic stenosis is the most frequent complication of arteriovenous fistula (AVF) for haemodialysis (HD). Treatment options are surgical bypass by creating a more proximal anastomosis or endovascular treatment by angioplasty. The available literature data show equal outcomes in term of secondary patency, but a significantly higher rate of recurrent stenosis for endovascular treatment (0.5 procedure/AVF/year). We describe the results of endovascular treatment by “double guide technique” (DGT) as to Turmel Rodrigues original description, in a series of patients referred to our centre. Method We describe all consecutive patients treated by DGT in the first semester of 2018 because of a de novo occurring juxta-anastomotic stenosis of the arteriovenous fistula for haemodialysis. The procedure was carried out as described by Turmell Rodrigues. In short: by means of a single retrograde access through the outflow vein by a 6 french valved introducer, two guide wire are navigated into both proximal and distal artery. Two consecutive dilatation of the anastomosis area are then performed including first the juxta-anastomotic vein at 6 to 7 mm (mean 6.7mm, ds 0.55), followed by the juxta-anastomotic artery at 4mm (mean 4.1mm, ds 0.33), as show in figures. Follow up was carried out at 1, 3, 6 12 month by clinical examination and ultrasound examination. Prospectively collected data was analyzed retrospectively. Results 25 patients were treated during the first 6 month of 2018 by a single operator. Patients data (mean): age 71years, HD vintage 31month, AVF vintage 31month. AVF distribution were: distal radio-cephalic 32%, proximal radio-cephalic 52%, distal ulnar-basilic 8%, humero-basilic 8%. Mean preoperative AVF blood flow - as measured by duplex ultrasound (US) - was 540ml/min. 32% of AVF have preoperative blood flow >600ml/min but a critical stenosis (<1.9mm of diameter). Mean juxta-anastomotic vein and juxta-anastomotic artery ballon diameter were 6.7mm (ds 0.55) and 4.1mm (ds 0.33) respectively. Overall mean blood flow at 12 month was 830ml/min. During follow up 3 patients required endovascular treatment of some new occurring stenosis, 3 patients were lost to follow up at 12 month, 1 patient died from unrelated reasons. In 52% of patients any other revision was required, while 32% required 1 further angioplasty, 4% 2 further angioplasty and 4% 4 further angioplasty of the target lesion during the following 12 month (recurrence rate: 0.28 procedure/patients/year). Assisted functional patency at 12month was 95%. Conclusion Endovascular treatment of juxta-anastomotic AVF stenosis by the DGT performed quite satisfactorily in our series and showed a low recurrence on the target lesion compared to data from literature. At 12 month the average AVF blood flow was below 1000ml/min. The technical advantage of the DGT consist in the single, small caliber percutaneous access, needed to complete the procedure. A larger series would confirm how this refinement of the technique compares with the improved results we preliminary observed.

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