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The aim of this study was to report our midterm results of percutaneous arteriovenous fistula (pAVF) creation using the Ellipsys (Avenu Medical, San Juan Capistrano, Calif) device and to present technical recommendations and our algorithm of pAVF maintenance. A single-center comprehensive database of all consecutive predialysis and end-stage renal disease patients who had a pAVF creation with the Ellipsys device was reviewed retrospectively. Study end points included technical success, maturation, functional patency, and required interventions. Between May 2017 and July 2019, there were 234 patients (mean age, 64 years; 148 male [63%]) who had a pAVF created. Technical success was achieved in 232 individuals (99%), and average duration of the procedure was 15 minutes (7-35 minutes). Average follow-up was 252 days (range, 83-696 days). The 1-year primary, primary assisted, and secondary patency rates were 54%, 85%, and 96%, respectively. Average pAVF flow was 923 mL/min (range, 425-1440 mL/min). There were no significant adverse events related to the procedure. Only three patients (1%) required a later conversion of the pAVF anastomosis to a surgical fistula. Twenty-four (10%) patients required superficialization of deep outflow veins because of difficult cannulation. Average maturation time was 4 weeks (range, 1-12 weeks). Fourteen patients (6%) had early (<2 weeks after creation) cannulation of the pAVF. The Ellipsys pAVF device allows the rapid and safe creation of a reliable autogenous access. Rates of technical success, patency, and maturation were excellent. For patients unsuited for a distal radiocephalic arteriovenous fistula, it should be considered the next preferred access option. [ABSTRACT FROM AUTHOR]

Abstract Objective We reviewed our initial experience creating a percutaneous arteriovenous fistula (pAVF) using a thermal resistance anastomosis device with proximal radial artery inflow. Methods A retrospective review was conducted of all patients who underwent a pAVF creation procedure between May 2017 and October 2017. Primary end points of the study were technical success, patency by Doppler ultrasound examination or angiography, flow levels achieved, time to first use, and pAVF-related complications. Results A pAVF was attempted in 34 patients with technical success in 33 individuals (97%). Patency of the pAVF was 94%. Mean access flow was 946 mL/min (brachial artery measurement) at the latest follow-up visit (53-229 days; average, 141 days). At 6 weeks, all fistulas have been used or were ready for dialysis by clinical examination or ultrasound examination. Only one patient required superficialization of the upper arm cephalic vein by lipectomy. There were no adverse events related to the pAVF creation or use, nor was there need for further interventions. Conclusions Successful pAVFs with proximal radial artery inflow were created with excellent initial results regarding technical success, patency, and safety. Advantages include avoidance of a surgical incision, short procedure times, good acceptance by patients, prompt access maturation, moderate flow, and low-pressure access, with possible reduction of risk for ischemic complications. Avoidance of vessel manipulation and side branch ligation might reduce risk of thrombosis and improve long-term patency and reduce need for further interventions. These early findings need to be confirmed in larger and longer follow-up studies. [ABSTRACT FROM AUTHOR]

Objective The objective of this study was to retrospectively evaluate the possibility of using the brachial veins despite their deep location, small caliber, and thin wall. Methods There were 64 patients without superficial veins who were eligible for two-stage brachial vein transposition (BrVT); 54 patients were on hemodialysis, 9 patients had sickle cell disease, and 1 patient had long-term parenteral nutrition. Preoperative imaging was performed with color duplex ultrasound as well as venography for suspected central vein stenosis. A surgical microscope was used to create an end-to-side anastomosis between the brachial vein (medial, if possible) and artery. No minimum vein diameter was required. Postoperative color duplex ultrasound imaging was scheduled at 1 month. Second-stage superficialization was performed 2 to 3 months later with tunnelization and a new arteriovenous anastomosis. Results For the 64 patients, cumulative primary patency rates (± standard deviation [SD]) at 1 year, 2 years, 3 years, and 4 years were 50% (±7%), 42% (±7%), 37% (±8%), and 27% (±11%), respectively. Primary assisted patency rates (±SD) at 1 year, 2 years, 3 years, and 4 years were 60% (±6%), 51% (±7%), 45% (±7%), and 37% (±9%), respectively. Secondary patency rates (±SD) at 1 year, 2 years, 3 years, and 4 years were 60% (±6%), 53% (±7%), 53% (±7%), and 45% (±8%), respectively. Early complications included thrombosis, nonmaturation, and upper arm edema. At the second stage (n = 50), four patients presented with unexplained major fibrosis extending cephalad from the first surgical site and preventing any dissection of the vein. Four patients had more usual complications (one nonmaturation, two occlusions of the brachial vein at the previous arteriovenous graft-vein anastomosis), and two were lost to follow-up. Vein transposition in a subcutaneous tunnel was technically unfeasible in eight patients. Of the 64 patients, 40 (62%) had a functional BrVT that was cannulated for effective dialysis after a median interval of 72 days (15-420 days) from the first stage. Mean cumulative secondary patency rates (from first cannulation) at 1 year, 2 years, and 3 years were 91% ± 5%, 72% ± 8%, and 62% ± 10%, respectively. Overall, 13 patients were lost to follow-up. Secondary complications were low flow and central vein occlusion. Long-term complications were related to stenosis and thrombosis, aneurysms, and puncture site necrosis. Median follow-up from the first stage was 1.62 years (0.02-11.3 years). Conclusions Despite many pitfalls for the surgeon, BrVT offers promising long-term patency. [ABSTRACT FROM AUTHOR]

Objective: Use of the Amplatzer vascular plug (AVP; St. Jude Medical Inc, St. Paul, Minn) for percutaneous occlusion of a hemodialysis arteriovenous access (AVA) is an emerging practice, and only a few reports by radiologists have been published. We report here a multidisciplinary experience of this technique not only for AVA occlusion but also for flow reduction in selected patients. Methods: This preliminary study includes a series of 20 plugs of different generations (I, II, and IV) used in 19 hemodialysis patients (two children, 17 adults). Of these, 15 AVAs were autologous fistulas located at the elbow, 4 were autologous forearm fistulas, and 1 was a brachial-basilic polytetrafluoroethylene graft. AVP deployment was through a 4F to 8F sheath, with oversizing from 30% to 50% to reduce the risk of migration. AVA occlusion (n = 14), by placing the AVP in the vein at its origin, was performed for central vein occlusion after unsuccessful percutaneous recanalization (n = 4), high flow (n = 2), hand ischemia (n = 3), successful kidney transplant (n = 1), and brachial-basilic or brachial-brachial fistula second-stage superficialization technical failure (n = 4). Vein/polytetrafluoroethylene grafts were not removed. AVA flow reduction (n = 6), by placing the AVP in the radial artery, was performed for well-tolerated high flow (n = 3) or high flow associated with distal ischemia (n = 3). All patients underwent a postoperative evaluation at 6-month intervals that included a clinical examination and duplex scan. Results: AVA occlusion or flow reduction was successfully achieved in all patients. Ischemia persisted in one patient and a revascularization with a distal bypass was necessary. Mean follow-up was 1.2 ± 0.8 years (range, 2 months-2.9 years). No plug migration, access revascularization, or other complication was observed. Conclusions: The results of this short preliminary study suggest that plug insertion for occlusion or for flow reduction in a hemodialysis AVA constitutes a reasonable alternative to coil insertion or to open surgery in selected patients. [Copyright &y& Elsevier]

Objective: To assess the efficacy of a Limberg skin flap to treat non-infected necrosis and bleeding at angioaccess puncture sites. Methods: Retrospective analysis of 40 selected (no infection, necrosis <20 mm diameter) patients (25 arteriovenous fistulae [AVF], 15 grafts) treated between 1998 and 2012 by rhomboid excision, vessel repair, and a locally rotated full-thickness Limberg skin flap together with early postoperative percutaneous transluminal angioplasty (PTA; n = 23/40). Success was defined as wound healing and angioaccess patency without complications. Results: Success rates at 1 and 6 months were 96% (24/25) and 76% (19/25), respectively, for AVF, and 80% (12/15) and 40% (6/15) for arteriovenous grafts. Complications included flap necrosis (n = 2), graft thrombosis (n = 4), minor sepsis (n = 1), death (n = 2), and new puncture site necrosis (n = 3). Four patients were lost to follow-up. Conclusions: Vessel or graft repair, PTA for distal stenoses and local debridement followed by a Limberg skin flap for tissue defects prevented further bleeding and maintained vascular access patency in 25/40 (62%) patients. [Copyright &y& Elsevier]

Introduction: When all access options in the upper limbs have been exhausted, an autogenous access in lower limb is a valuable alternative to arteriovenous grafts. We report our experience of transposition of the femoral vein (tFV). Methods: From June 1984 to June 2011, 70 patients underwent 72 tFV in two centers (Paris and Meknès) with the same technique. All patients had exhausted upper arm veins or had central vein obstructions. Patients were followed by serial duplex scanning. All complications were recorded and statistical analysis of patency was performed according to intention to treat using the life-table method. Results: The mean interval between initiation of dialysis and creation of the tFV was 10 years. The sex ratio was even (one female/one male). Mean age was 48 years (range, 1-84 years), and there were no postoperative infections. Duplex measurements in 33 patients indicated high-flow: mean = 1529 ± 429 mL/min; range, 700-3000 mL/min. Two immediate failures were observed and four patients were lost to follow-up soon after the access creation. Ten patients (14%) experienced minor complications (hematoma, five; lymphocele, one; delayed wound healing, two; distal edema, two) and 30 patients (42%) experienced mild complications (femoral vein and outflow stenosis, 16 [treated by percutaneous transluminal angioplasty, 13, or polytetrafluoroethylene patch, three]; puncture site complications, three [ischemia, two; infection, one]; reversible thrombosis, three [two surgical and one percutaneous thrombectomy]; abandoned thrombosis, eight [11%] after a mean patency of 8.1 years). Thirteen patients (18%) experienced major complications necessitating fistula ligation (ischemic complications, five diabetic patients with peripheral arterial occlusive disease [one major amputation included]; lower leg compartment syndrome, one; acute venous hypertension, two; secondary major edema, two; high-output cardiac failure, one; bleeding, two). All the patent accesses (59/72) were utilized for dialysis after a mean interval of 2 ± 1 months (range, 1-7 months) resulting in an 82% success rate. According to life-table analysis, the primary patency rates at 1 and 9 years were 91% ± 4% and 45% ± 11%, respectively. The secondary patency rates at 1 and 9 years were 84% ± 5% and 56% ± 9%, respectively. Conclusions: Femoral vein transposition in the lower limb is a valuable alternative to arteriovenous grafts in terms of infection and long-term patency. Secondary venous percutaneous angioplasties may be necessary. High flow rates are frequently observed and patient selection is essential to avoid ischemic complications. [Copyright &y& Elsevier]

Objective: This retrospective study analyzed the characteristics, potential risks, and therapeutic options of true aneurysms of the donor artery in arteriovenous fistulas (AVFs) for dialysis access. Methods: We retrospectively collected data of patients with aneurysmal degeneration (AD) after AVF creation from surgeons who were members of the French Society for Vascular Access, treated from January 2006 to May 2011. The study excluded patients with pseudoaneurysms. Patient demographics, type of access, aneurysm characteristics, symptoms, treatment, and follow-up were recorded. Results: Seven men and three women (mean age, 38.1 ± 5.3 years) were identified with AD (mean diameter, 44.5; range, 24-80 mm) Mean duration of access was 83.6 ± 48.8 months. Diagnosis of AD was at 117.5 ± 53.8 months after access creation. The initial access was radiocephalic, six; ulnobasilic, one; brachiocephalic, two; and brachiobasilic, one. Three patients had two successive accesses: one brachioaxillary polytetrafluoroethylene (PTFE) graft and two proximalizations of a failed radiocephalic AVF. Symptoms were pain and swelling, four; pain related to total thrombosis without signs of ischemia, two; median nerve compression, two; pain related to contained rupture, one; and subacute ischemia due to embolic occlusion of both radial and interosseous arteries, one. AD location was brachial, seven; axillary, one; radial, one; and ulnar, one. Eight patients underwent surgical aneurysm excision associated with interposition bypass using great saphenous vein, two; basilic vein, one; PTFE, three; Dacron, one; and allograft, one. Two patients needed secondary PTFE bypass because of progression of AD to the inflow artery and dilatation of the venous bypass. With a mean follow-up of 20.3 ± 17 months, all bypasses but one remained patent. Conclusions: AD is a rare but significant complication of vascular access. Surgical correction should be discussed in most cases due to potential complications. After resection, the choice of reconstructive conduit is not straightforward. [Copyright &y& Elsevier]

Abstract: Objective: Juxta-anastomosis proximal radial artery ligation (PRAL) is a new surgical technique for reduction of excessive blood flow of radial cephalic fistulas (RCFs). Patients and methods: This prospective study included 37 consecutive patients (eight children and 29 adults) who underwent PRAL of high-flow RCFs causing ischaemia (n = 2), aneurysmal degeneration of the vein (n = 14), and cardiac insufficiency (n = 7) or for prevention of cardiac overload (n = 14). Mean fistula age was 2.6 years for children and 7.4 years for adults. None had diabetes. Anatomical prerequisites (side-to-end anastomosis fistula and retrograde flow in the distal radial artery) were checked by ultrasound or angiography. Division and ligation of the juxta-anastomosis proximal radial artery were performed under regional anaesthesia. Patency following ligation was estimated according to the life table method. Results: The success rate was 92% (34/37). The three failures included one excessive and two insufficient reductions of flow (<33%). Mean flow reduction rates were 50% in children and 53% in adults. Primary patency rates at 1 and 2 years were 88% ± 6% and 74% ± 9%, respectively. Secondary patency rates were 88% ± 6% and 78% ± 8%, respectively. Conclusion: PRAL is a simple, safe, and effective technique for reduction of flow in RCFs. [Copyright &y& Elsevier]

Background: Forearm artery lesions are a frequent cause of distal fistula maturation failure. Surgical treatment is difficult because of highly calcified arteries. To redo the arteriovenous anastomosis higher up the forearm is technically difficult and often ineffective because arteries cannot be enlarged. It also causes a loss in puncture zone. Creation of brachial accesses leads to a high risk of distal ischemia. Methods: From September 2000 to September 2006, we performed percutaneous transluminal angioplasty (PTA) of forearm arteries in 25 patients with failing distal access maturation. We reported immediate results of the dilatation and retrospectively analyzed the outcome of the accesses after the procedure. Results: Forearm artery PTA was achieved in all 25 patients. Three main complications occurred: severe spasms precluding precise assessment of the artery patency after dilatation, rupture easily treated by prolonged low-pressure balloon inflation, and early rethrombosis leading to access loss. Follow-up was available in 23 patients. PTA failed to restore a sufficient access flow in two patients (the access loss and an insufficient increase in flow). In the remaining 21 (91%), accesses started to be used for hemodialysis without difficulties. Primary patency access rates after PTA were 83% (range, 60%-93%) at 1 year and 74% (range, 47%-89%) at 2 years. Secondary access patency rates were 86% (range, 64%-95%) at 1 and 3 years. Conclusion: When a distal access fails to mature because of forearm artery lesions, PTA should be done and will salvage the fistula without risk of distal ischemia and cardiac failure. Efficacy of PTA clearly influences surgical strategy and is a major argument in favor of attempting to create distal accesses in patients with mild distal artery lesions. Even in cases of failure, such as early occlusion of the fistula, this technique does not jeopardize further proximal access creation. Forearm access creation should be avoided only in cases of extremely severe distal artery lesions. [Copyright &y& Elsevier]

Objective: All surgical methods published to date for the reduction of excessive high-flow in native elbow fistulas for dialysis have limitations. We report a new surgical approach to flow reduction by transposition of the radial artery to the elbow level. Methods: From 1992 to 2008, 47 consecutive patients (22 women) with brachial artery to elbow vein autogenous fistula underwent flow reduction via replacement of brachial artery by transposed distal radial artery inflow. Fistulas were side-to-end either brachial-cephalic (19) or brachial-basilic (28). The indications were hand ischemia (4), cardiac failure (13), concerns about future cardiac dysfunction (23), and chronic venous hypertension resulting in aneurysmal degeneration of the vein (7). Mean patient age was 44 years, 11% were diabetic, 17% were smokers, and mean BMI was 22. Mean fistula age before flow reduction was 2.5 years. Results: Technical success was 91% (43 of 47). The mean flow rate dropped by 66% ± 14%. Clinical success in symptomatic patients was 75% (18 of 24). The fistula eventually had to be ligated in three cases of cardiac failure because of insufficient clinical improvement. All four patients with hand ischemia were cured, with no recurrence during follow-up. Primary patency rates at one and three years were 61% ± 7% and 40% ± 8%. Secondary patency rates at one and three years were 89% ± 5% and 70% ± 8%. Conclusion: Transposition of the radial artery, a safe and effective technique, might now be considered in the surgical armamentarium of flow reduction techniques. [Copyright &y& Elsevier]

Microsurgery gives much better immediate and long term results than classical surgery for the creation of direct arteriovenous fistulae, the best chronic access to blood in children. [Copyright &y& Elsevier]

Background: The depth of veins can discourage surgeons from creating radial-cephalic arteriovenous accesses for hemodialysis in obese patients. Elevation and tunneled transposition are the two techniques that have been described to superficialize these veins and make them accessible for cannulation. Unfortunately, such manipulation of veins has potential drawbacks. We report lipectomy, a new technique that removes subcutaneous fat and does not mobilize the vein. Methods: This single-center prospective study included 49 consecutive patients (17 men, 32 women) who underwent second-stage lipectomy after creation of a radial-cephalic fistula. Mean patient age was 54 years, 36% had diabetes, and the mean body mass index was 31 ± 5.6 kg/m2. Subcutaneous fatty tissues were removed after two transverse skin incisions under regional anesthesia and preventive hemostasis. Cannulation was first allowed 1 month later, after clinical and color duplex ultrasound evaluation. Technical success was defined as the ability to remove the fat and to palpate the patent vein immediately under the skin at the end of the operation. Clinical success was defined as the ability to perform at least three consecutive dialysis sessions with two needles. All patients were checked systematically every 6 months by the surgeon. Results: Technical and clinical success rates were 96% (47 of 49) and 94% (46 of 49), respectively. Mean vein depth decreased from 8 ± 2 to 3 ± 1 mm according to duplex ultrasound imaging. The mean vein diameter increased from 6 ± 1 to 8 ± 2 mm. In one patient, vein tortuosity that was overlooked required conventional repeat tunneling. One extensive hematoma resulted in loss of the fistula. One patient died before the fistula could be used. Primary patency rates were 71% ± 7% and 63% ± 8% at 1 and 3 years, respectively, and secondary patency rates were 98% ± 2% and 88% ± 7%. Delayed complications were treated by surgery (n = 7) or by endovascular procedures (n = 10). Conclusion: Lipectomy is a safe, effective, and durable approach to make deep arterialized forearm veins accessible for routine cannulation for hemodialysis in obese patients. It might even be hypothesized that incident obese dialysis patients will eventually have the highest proportion of radial-cephalic fistulas because they often have distal veins that have been preserved by their fat from previous attempts at cannulation for blood sampling or infusion. [Copyright &y& Elsevier]

The purpose of this manuscript is to describe the clinical course of a 66-year-old patient with chronic kidney disease due to focal segmental glomerulosclerosis in whom an access arteriovenous fistula was created in the anatomical snuffbox. At discharge, the fistula thrill was normal. Two months later, a duplex examination revealed previously unrecognized obstruction of the mid-forearm segment of the cephalic vein; flow was maintained by a perforator into the deep venous system, which returned blood to the upper arm cephalic vein above the occlusion. A second, subsequent radiocephalic anastomosis was performed in the wrist to augment flow. The fistula was successfully cannulated after 12 weeks of maturation., Competing Interests: None., (© 2024 The Authors.)

Background: Stent placement in the cannulation zone of AVF is becoming alarmingly frequent and sometimes in cases where surgical management would be more appropriate. When complications arise repair can be particularly challenging. We present our experience and management of this problem., Methods: We report our experience on three patients (two females and one male, mean age 72) that were referred to our department for problems related to stents placed at the cannulation segments., Results: All patients required complex surgical interventions. In two of them maintenance of access was possible but required the use of a graft. In one complete resection of the AVF and all stents was necessary, and the patient remained on dialysis through catheter., Conclusion: Stent placement at the cannulation zones may complicate access management in the future and should be avoided if possible.

Objective: We evaluate the creation of a percutaneous proximal radial artery-radial vein arteriovenous fistula with Ellipsys ® instead of the usual first-stage brachial artery fistula prior to a second-stage brachial vein elevation, in patients with inadequate cephalic and basilic veins., Methods: Single center study of eight patients (six males, mean = 54 years) who underwent a two-stage brachial vein elevation procedure between May 2017 and October 2019. Inclusion criteria were life expectancy > 6 months, patent brachial and proximal radial artery (>2 mm in diameter) absent/inadequate cephalic and basilic veins, existence of a brachial vein >3 mm in diameter, and in continuity with a proximal radial vein > 2 mm in diameter., Results: Technical success was 100%. Four patients required angioplasty of a juxta-anastomotic stenosis, accounting for a 6-month primary and secondary patency rates were 68% and 100%, respectively. Access flow averaged 982 mL/min (range 768-1586) at final follow-up evaluation. There were no significant adverse events related to the procedures. All fistulae were elevated at 4-12 (mean: 8) weeks post creation and were successfully cannulated with two needles after healing was completed (2-4 weeks after elevation). No patients developed hand ischemia or arm edema., Conclusions: Percutaneous creation of a proximal radial artery-radial vein fistula followed by brachial vein elevation is a safe and reliable option for autogenous access creation in patients with inadequate cephalic or basilic veins. Minimally invasive radial artery inflow and longer available length of the targeted brachial vein available for elevation are the main advantages in skilled hands.

Objective: To investigate the feasibility of percutaneous arteriovenous fistula creation in consecutive patients screened for first access creation., Methods: Prospective study of ultrasound mapping based on the following minimal anatomic requirements: a patent proximal radial artery and adjacent elbow perforating vein with straight trajectory, each greater than or equal to 2 mm in diameter and within 1.5 mm of each other. In addition, the same population was evaluated for feasibility of a distal radiocephalic fistula established., Results: One hundred consecutive patients were examined between November 2018 and January 2019. Sixty-seven were male (67%) and mean age was 61 years. Sixty-three patients (63%) and a total of 100 limbs (50%) were found to be eligible for a percutaneous fistula creation with Ellipsys ® . Thirty-seven percent of patients were ineligible because of the absence of both median cephalic and median cubital veins (15%), absence or inadequate elbow perforating vein and/or smaller than 2 mm proximal radial artery (14%), and/or distance greater than 1.5 mm (8%). We found suitable vessels for a surgical distal fistula creation in 91 extremities (45%), but this percentage dropped to 17% in patients over 70 years old. Among the 100 limbs eligible for percutaneous arteriovenous fistula, only 30 (30%) were eligible for radiocephalic arteriovenous fistula., Conclusion: More than 60% of patients were eligible for Ellipsys. The absence of veins at the elbow and a large distance between vessels were the most common limiting factors. Less than one half of the patients were candidates for surgical fistula and this percentage dropped significantly for older individuals.

Objective: To investigate the hemodynamics of percutaneous arteriovenous fistulae (pAVF) created between the proximal radial artery and the deep communicating vein of the elbow., Methods: Consecutive patients with a percutaneously created proximal radial artery to perforating vein arteriovenous fistulae were evaluated and compared with control patients with clinically well-functioning surgical wrist radiocephalic arteriovenous fistulae (sWRC-AVF)., Results: Thirty-one patients with a pAVF (21 males - 68%, mean age: 62 years, range: 53-81), with mean follow-up of 254 days (range: 60-443) and 32 patients with a surgical fistula (20 males - 62%, mean age of 63 years, range: 30-84) were evaluated. Mean access flow and distribution range were similar in the two study groups, with a mean flow of 859 mL/min vs 919 mL/min, respectively. There was no significant difference in the mean radial artery diameter (4 mm vs 4.3 mm, p  = 0.2). Statistically significant trends were observed for resistive index (0.57 pAVF vs 0.52 (0.07) and brachial vein cross-sectional area (13 pAVF vs 33 mm 2 , p  = 0.06). The arteriovenous anastomosis area was significantly smaller with pAVFs (13 vs 43 mm 2 , p  = 0.002) and the pressure difference between extremities was less for the pAVF group vs sWRC-AVF (19 vs 27 mm Hg, respectively, p  = 0.03). Existence of single cephalic or basilic versus cephalic and basilic outflow did not affect vein maturation or overall flow., Conclusions: pAVF have a favourable hemodynamic profile with many similarities when compared with surgically created wrist fistulae. Cephalic and/or basilic vein matured with only minor outflow shunted to the deep venous system.

Background: There are three principle forms of vascular access available for the treatment of children with end stage kidney disease (ESKD) by haemodialysis: tunnelled catheters placed in a central vein (central venous lines, CVLs), arteriovenous fistulas (AVF), and arteriovenous grafts (AVG) using prosthetic or biological material. Compared with the adult literature, there are few studies in children to provide evidence based guidelines for optimal vascular access type or its management and outcomes in children with ESKD., Methods: The European Society for Paediatric Nephrology Dialysis Working Group (ESPN Dialysis WG) have developed recommendations for the choice of access type, pre-operative evaluation, monitoring, and prevention and management of complications of different access types in children with ESKD., Results: For adults with ESKD on haemodialysis, the principle of "Fistula First" has been key to changing the attitude to vascular access for haemodialysis. However, data from multiple observational studies and the International Paediatric Haemodialysis Network registry suggest that CVLs are associated with a significantly higher rate of infections and access dysfunction, and need for access replacement. Despite this, AVFs are used in only ∼25% of children on haemodialysis. It is important to provide the right access for the right patient at the right time in their life-course of renal replacement therapy, with an emphasis on venous preservation at all times. While AVFs may not be suitable in the very young or those with an anticipated short dialysis course before transplantation, many paediatric studies have shown that AVFs are superior to CVLs., Conclusions: Here we present clinical practice recommendations for AVFs and CVLs in children with ESKD. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system has been used to develop and GRADE the recommendations. In the absence of high quality evidence, the opinion of experts from the ESPN Dialysis WG is provided, but is clearly GRADE-ed as such and must be carefully considered by the treating physician, and adapted to local expertise and individual patient needs as appropriate., (© The Author(s) 2019. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.)

Arteriovenous access ischaemic steal (AVAIS) is a serious and not infrequent complication of vascular access. Pathophysiology is key to diagnosis, investigation and management. Ischaemia distal to an AV access is due to multiple factors. Clinical steal is not simply blood diversion but pressure changes within the adapted vasculature with distal hypoperfusion and resultant poor perfusion pressures in the distal extremity. Reversal of flow within the artery distal to the AV access may be seen but this is not associated with ischaemia in most cases.Terminology is varied and it is suggested that arteriovenous access ischemic steal (AVAIS) is the preferred term. In all cases AVAIS should be carefully classified on clinical symptoms as these determine management options and allow standardisation for studies.Diabetes and peripheral arterial occlusive disease are risk factors but a 'high risk patient' profile is not clear and definitive vascular access should not be automatically avoided in these patient groups.Multiple treatment modalities have been described and their use should be directed by appropriate assessment, investigation and treatment of the underlying pathophysiology. Comparison of treatment options is difficult as published studies are heavily biased. Whilst no single technique is suitable for all cases of AVAIS there are some that suit particular scenarios and mild AVAIS may benefit from observation whilst more severe steal mandates surgical intervention.

High-flow in hemodialysis arteriovenous angioaccesses is frequent. It may result in high-output cardiac failure, which should be prevented by fistula flow reduction. The most frequently reported flow reduction procedure is banding but immediate and long-term results are questionable. Alternative techniques are related here with personal results. Juxta-anastomosis "Proximal Radial Artery Ligation" (PRAL) is a very simple and effective reduction technique for side-to-end radio-cephalic fistulas (82 patients; reduction rate [RR]: 54% ± 19%). For brachial artery-based fistulas flow reduction two variants of Revision Using Distal Inflow (RUDI) procedures are used: 1) RUDI-1 using a polytetrafluoroethylene (PTFE) graft or a greater saphenous vein, which we first described in 1989 as "Distal Report of the Arterial Inflow" (35 patients; RR: 53% ± 18%), 2) RUDI-2 procedure, "Transposition of the Radial Artery", which we described in 2009 (47 patients; RR: 66% ± 14%).

Purpose: The purpose of this study is to report surgical techniques to facilitate cannulation of deep matured veins., Methods and Results: 1) Basilic vein tunnel superficialization with rerouting in an anterior tunnel is mandatory for brachial-basilic arteriovenous fistula (AVF), mostly performed in a second surgical stage. The elevation technique, which could necessitate cannulation of the vein through the overlying scar, is not advisable. 2) Femoral vein superficialization is a one-stage surgical operation. Complications of this high-flow AVF are distal ischemia (diabetes and occlusive arterial disease are contraindications), iliac vein stenosis due to intimal hypertrophy and cardiac issues. Nevertheless, we have achieved high long-term patency rates (N = 70). Primary patency rates at 1 and 9 years were 91% ± 4% and 45% ± 11%, respectively. Secondary patency rates at 1 and 9 years were 84% ± 5% and 56% ± 9%, respectively. 3) Lipectomy for superficialization of the forearm radial-cephalic AVF is described for obese patients. Subcutaneous tissues are resected using two transverse incisions. Mobilization of the vein is avoided. At 3 years (N = 49), we recorded 63% ± 8% and 88% ± 7% primary and secondary patency rates, respectively. Anterior transposition of the forearm basilic vein is not necessary when using microsurgery for creation of distal ulno-basilic AVF. 4) VWING is a novel surgically implanted device to help buttonhole technique cannulation. It is too early to draw any conclusion from the preliminary published reports., Conclusions: Tunnel-transposition and lipectomy are efficient techniques to allow easy needling of deeply situated upper-arm basilic vein, and cephalic vein in obese patients, respectively.

Forearm arteriovenous fistula (AVF) is a direct anastomosis between the radial artery and the cephalic vein or the ulnar artery and the basilic vein, which are small-caliber vessels. The surgical technique must be precise to avoid postoperative stenosis of the anastomosis which may result in early thrombosis or nonmaturation. In our experience, microsurgery and preventive hemostasis are two major contributions to creation of forearm AVF. Using these techniques, construction of a radial-cephalic fistula was possible in 78% of children in our hospital, with 60% secondary patency rates at 4 years. In a personal unpublished series, 69% of the first arteriovenous angioaccess of adult patients were forearm fistulae, with 63% and 91% primary and secondary 1-year patency rates, respectively. Finally, 68% primary patency and 96% secondary patency rates at 1 year were reported by Pirozzi et al. in adults with an internal diameter of <1.6 mm in the radial artery.

Objectives: The distal basilic forearm vein is frequently preserved and might be used more frequently for placement of an ulnar-basilic autogenous arteriovenous access (UB-AAVA) in the wrist despite the small size of the two vessels. The scarcity of publications led us to initiate a prospective study regarding the placement and outcomes of UB-AAVAs., Methods: Seventy patients (63 adults, seven children) with no usable cephalic vein in either forearm were selected consecutively over 4 years for placement of a UB-AAVA. The prerequisite was a clinically visible or palpable forearm basilic vein after placing a tourniquet. Regional anesthesia, prophylactic hemostasis, and a surgical microscope were used systematically. Secondary superficialization was performed in two patients. Most non-matured accesses were abandoned in favor of the placement of a more proximal autogenous access. Mean follow-up was 20 months (SD =15)., Results: Immediate patency was obtained in 94% of adults and 100% of children. Success (in-use access) was achieved in 60% of patients (38/63 adults and 6/7 children) after a mean postoperative interval of 80 days (SD = 64; range, 31-277). Failures included four immediate thromboses, one postoperative death, and 21 never-matured accesses. No steal syndrome was observed. Initial failures included, primary patency rates in adults at 1 and 2 years were 42% ± 6% and 30% ± 7%, respectively; secondary patency rates at 1 year and 2 years were 60% ± 6% and 53% ± 7%, respectively., Conclusions: Although patency rates are not as good as those achieved with radial cephalic-AAVA, the UB-AAVA is an alternative autogenous forearm access before the placement of any other access involving the basilic vein. The use of the surgical microscope is mandatory, and more than usual time is required to achieve maturation., (Copyright © 2011 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)

Microsurgery for angioaccess in children includes the use of a surgical microscope, microsurgical instruments, prophylactic tourniquet-induced hemostasis and no-touch surgery. In the recent publications concerning angioaccess in children, the percentages of grafts versus arteriovenous fistulas (AVF) varied from 54 to 76% without microsurgery, and from 0 to 14% with microsurgery. Similarly, the percentages of AVF which failed to mature varied from 30 to 33% without microsurgery, and from 5 to 10% with microsurgery. In a personal series of 380 children receiving hemodialysis, 434 microsurgical angioaccesses were created, 78% being distal autologous AVF. Eighty-five percent of the distal radial-cephalic AVF were patent after 2 years and 60% after 4 years. These results of microsurgically created AVF are probably responsible, at least in part, for the high percentage of end-stage renal disease (ESRD) children treated by hemodialysis on 1 February 2003 in Paris using an autologous fistula (70% of 33 children), while only 24% were hemodialyzed via a central venous catheter and 6% were on peritoneal dialysis. This compares favorably with the annual publication of the North American Pediatric Renal Transplant Cooperative Study in 1996 reporting that two-thirds of the dialysis population were maintained on peritoneal dialysis and that the majority of hemodialysis accesses were external percutaneous catheters. Microsurgical AVF are also created successfully in non-ESRD children requiring frequent blood access for various chronic diseases. It has been possible to create a distal AVF in 68% of cases and the long-term patency rate was just below 60% after 10 years. Microsurgery is mandatory for creation of arteriovenous fistulas, the best form of angioaccess for children treated by hemodialysis or requiring repeated access to blood in various non-renal diseases.

Purpose: Posttransplant lymphoproliferative diseases (PTLDs) represent a group of potentially lethal lymphoid proliferations that may complicate the course of solid organ transplantation. Although early-onset PTLDs frequently have a favorable outcome, late-onset PTLDs behave more alike aggressive lymphoma. We report a monocentric retrospective study that focused on PTLDs occurring later than 1 year after kidney transplantation (very late-onset PTLDs) to define their incidence, clinical presentation, pathologic features, and outcome. We particularly emphasized the follow-up of patients treated with conventional chemotherapy., Patients and Methods: The medical histories of all patients who developed very late-onset PTLD in our institution were reviewed, and diagnostic biopsy materials were retrospectively studied., Results: Very late-onset PTLDs were diagnosed in 16 (1.1%) of 1,421 patients. Mean (+/- SD) time to tumor onset was 103.93 +/- 70.88 months. Most tumors were Epstein-Barr virus-related monomorphic large-cell PTLDs of B phenotype. Ten patients received conventional chemotherapy (cyclophosphamide, doxorubicin, vincristine, and prednisone regimen). Two of them died within 2 months, two achieved partial remission, and six achieved definitive complete remission. Overall median survival time was 13 months and rose to 27 months in the treated group. The main cause of mortality was sepsis. None of the treated patients experienced rejection despite withdrawal of immunosuppressive treatment., Conclusion: Despite characteristics of aggressive lymphoma, very late-onset PTLDs after renal transplantation may respond to conventional chemotherapy. However, because a high rate of infectious complications occurred, new therapeutic strategies, such as combinations of anti-CD20 monoclonal antibodies and lower doses of chemotherapy, are warranted.

Expression of NG2 has been reported in the majority of paediatric acute leukaemia (AL) cases with MLL rearrangement. We demonstrated 7. 1 positivity in 2/3 paediatric and 4/11 adult MLL rearranged acute myeloid leukaemia (AML) but in 0/28 adult AML without MLL rearrangement, thus extending the 100% specificity to adult cases. Positivity correlated with stage of maturation arrest since it was found in 0/6 immature AML but in 6/8 monoblastic cases. These data demonstrate that, if NG2 expression in AL is the (in)direct result of MLL rearrangement, such activation is restricted to a monoblastic population in AML. They also have practical implications for NG2 diagnostic screening strategies.

Appropriate staging and evaluation of residual disease is critical to improving the treatment of patients with lymphoma. The specific expression of homing receptors may determine the preferential dissemination pattern of tumoral cells. We investigated the expression of the mucosal homing receptor alpha4beta7 on tumoral cells from peripheral lymph node in patients with newly diagnosed mantle cell lymphoma (MCL) to check whether it is associated with gastrointestinal involvement. Expression of the alpha4beta1 integrin and the peripheral lymph node addressin CD62L were also examined. Thirteen MCL patients presenting with peripheral lymphadenopathy were studied. Expression of the mucosal homing receptor integrin alpha4beta7 by peripheral lymph node lymphoma cells was found to be frequent (5/13) and associated with gastrointestinal involvement (5/7). In contrast, lymphoma cells from patients without gastrointestinal involvement did not express alpha4beta7 (6/6) (P = 0.03). These data suggest that alpha4beta7 integrin is expressed by a subset of MCLs and that its expression may predict digestive tract involvement in MCL, furnishing a basis for recognizing two distinct clinical and phenotypic forms, ie, "digestive homing (or digestive primitive)" versus "peripheral" MCL. Further studies on more patients will be needed to understand the impact of biological differences on the prognosis of these two clinical forms.

The rapid detection of chromosome band 8q24 rearrangements, including classical translocations involving MYC and variant 3' translocations, is important for the accurate diagnosis and appropriate treatment of lymphoid malignancies. We have identified and characterized a CEPH YAC, 934e1, which extends from at least 190 kbp upstream to over 280 kbp downstream to MYC, allowing detection of classical t(8; 14)(q24;q32) and variant t(8;22)(q24;q11) and t(8;14)(q24;q11), extending distal to PVT1 and therefore, by extrapolation, to BVR1. This YAC also allowed clarification of complex chromosome 8 abnormalities and the identification of translocations in interphase nuclei. A second CEPH YAC, 904c3, previously shown to contain the PVT1 locus but not MYC, allowed distinction between translocations occurring centromeric and telomeric to MYC. Use of the 934e1 YAC will aid classification of a variety of lymphoid proliferations and further characterization of rearranged cases with the 904c3 YAC will simplify mapping of their diverse breakpoints.

The TAL1 gene is disrupted by translocation or deletion (tal(d)) in up to 30% of T-cell acute lymphoblastic leukaemia (T-ALL), leading to aberrant transcriptional activation, as a SIL-TAL1 fused transcript in tal(d). It has been suggested that TAL1 transcription occurs in approximately 50% of a T-ALLs without apparent rearrangement. SIL-TAL1 was positive in 15/60 (25%) of T-ALL, whereas wild-type TAL1 transcripts were detected in all 13 SIL-TAL1 and in 19/43 (44%) T-ALL without SIL-TAL1. To investigate the cellular origin of TAL1 we exploited the fact that GATA1 and TAL1 are co-ordinately expressed in non-lymphoid haemopoietic cells, whereas only the latter is found in T-ALL. GATA1 was detected in 10/23 (43%) TAL1-negative T-ALLs but in 17/19 (89%) 'unexplained' TAL1-positive cases, suggesting a common non-lymphoid cellular origin. Immunocytochemical analysis with a TAL1-specific monoclonal antibody showed nuclear expression in the blasts of 10/34 (29%) cases, including 8/10 SIL-TAL1+ and two RT-PCR TAL1+, SIL-TAL1- cases. In the remaining cases TAL1 expression was restricted to a minor population (< 5%) of larger, strongly TAL1-positive cells which comprised erythroid cells, CD34+ CD3- precursors and an unidentified TAL1+ CD45- population which morphologically resembled monocytes/macrophages. We therefore suggest that appropriate diagnostic evaluation of T-ALL should include molecular detection of SIL-TAL1 transcripts and in situ immunocytochemical detection of TAL1 protein expression by leukaemic blasts. This approach will enable accurate analysis of the prognostic significance of TAL1 deregulation in T-ALL.