Standardized Methodology for Duplex Ultrasound Examination of Arteriovenous Access for Hemodialysis: A Proposal of the French Society of Vascular Medicine and the French-Speaking Society of Vascular Access.

Duplex ultrasound (DUS) is an essential tool for characterizing and monitoring arteriovenous (AV) access for hemodialysis. The aim of the work described here, requested by the French Society of Vascular Medicine in collaboration with the French-Speaking Vascular Access Society, is to propose a standardized methodology for performing and documenting DUS, taking into account the variety of AV access techniques and the problems routinely encountered. A steering committee reviewed the literature and selected the relevant references. A draft was prepared, and all items with missing or conflicting data were submitted to a Delphi consensus. The final document was discussed and approved by all participants. The principles of DUS evaluation of AV access consist of examination of the afferent artery, the anastomosis and the entire venous drainage system. DUS uses B-mode ultrasound, color flow, pulsed wave and power Doppler analysis. DUS can be used in a variety of clinical situations, which can directly influence the methodology of the examination and the interpretation of the results. Blood flow should be assessed as it correlates with the risk of thrombosis. The measurement should be adapted to the different anatomical and hemodynamic conditions encountered. Characterization of stenosis should take into account the residual diameter of the drainage vein and its hemodynamic consequences. Other complications can be assessed with a standardized DUS examination. When performed according to a rigorous methodology, DUS of the AV access allows a comprehensive assessment of its functionality and eliminates the need for further invasive diagnostic procedures.

Creating percutaneous radiocephalic arteriovenous fistulas at the wrist.

BACKGROUND: The first arteriovenous fistulas were created at the wrist more than 60 years ago. Basic surgical construction techniques remain unchanged with mobilization and repositioning of the vessels followed by a sutured anastomosis. We used the Ellipsys device to construct percutaneous radiocephalic-arteriovenous fistulas at the wrist and report the results. METHODS: Data were reviewed retrospectively for all patients who had a percutaneous radiocephalic-arteriovenous fistula created during a 6-month period. Each individual underwent ultrasound vessel mapping in addition to physical examination. When a radiocephalic-arteriovenous fistula was feasible and a communicating vein ⩾ 2 mm in diameter was noted in the distal forearm along with a radial artery ⩾ 2 mm, a percutaneous radiocephalic-arteriovenous fistula was considered and reviewed with the patient. RESULTS: Four individuals met the criteria to consider a percutaneous radiocephalic-arteriovenous fistula and all elected to have the procedure performed. Ages were 54-85 years. Three were diabetic and one was female. All percutaneous radiocephalic-arteriovenous fistulas were technically successful. Two individuals had not yet started dialysis therapy. Successful and repetitive cannulation for the two individuals with catheters was initiated at 4 and 8 weeks post procedure. The two pre-dialysis patients had physiologic arteriovenous fistula maturation (6 mm vein diameter and >500 mL/min flow) at 4 and 12 weeks. There were no procedural or late complications and none required intervention. Follow-up was 8-23 months (mean 16 months). CONCLUSION: The success of these percutaneous radiocephalic-arteriovenous fistulas suggests that use of the Ellipsys device will be applicable at the wrist in selected patients where appropriate vessel sizes and configurations are found.

Midterm results of percutaneous arteriovenous fistula creation with the Ellipsys Vascular Access System, technical recommendations, and an algorithm for maintenance.

OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Ultrasound evaluation of percutaneously created arteriovenous fistulae between radial artery and perforating vein at the elbow.

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 mm2, p = 0.06). The arteriovenous anastomosis area was significantly smaller with pAVFs (13 vs 43 mm2, 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.

Feasibility for arteriovenous fistula creation with Ellipsys®.

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.

Ultrasound dilution and thermodilution versus color Doppler ultrasound for arteriovenous fistula assessment in children on hemodialysis.

BACKGROUND: This study is aimed at comparing ultrasound dilution (UD) and thermodilution (TD) with color Doppler ultrasound (CDU) for arteriovenous fistula (AVF) assessment in children on hemodialysis (HD). MATERIAL AND METHODS: All patients were dialysed with the Fresenius 5008 HD machine. UD was performed using the Transonic device. The two methods were compared with CDU performed on a non-HD day. AVF flow rate was expressed as ml/min/1.73 m2. RESULTS: Sixteen measurements of AVF flow rate and recirculation with UD and TD were compared with CDU in 16 patients with a median weight of 39 kg. Both UD and TD overestimated AVF flow rate when compared with CDU (+437 (95% CI + 200, + 674) and + 476 (95% CI + 80, + 871) ml/min/1.73 m2 for UD and TD, respectively). CDU flow rate was significantly correlated to UD flow rate (r2 = 0.761, p < 0.001), but not to TD flow rate (r2 = 0.164, p = 0.120). Although recirculation in all AVF was estimated to be 0% and < 15% with UD and TD, respectively, 7 significant stenoses were diagnosed by CDU. AVF with stenosis had lower flow rates when measured by CDU, UD or TD, but only CDU measurements reached statistical significance (p = 0.008, p = 0.142 and p = 0.174, respectively). CONCLUSION: UD and TD overestimate AVF flow rate when compared with CDU, which is the most reliable non-invasive method for screening vascular access for stenosis. UD seems more accurate than TD for AVF flow rate assessment. Recirculation via UD or TD should not be used for early screening of AVF stenosis in children on HD.

Clinical hemodialysis experience with percutaneous arteriovenous fistulas created using the Ellipsys® vascular access system.

INTRODUCTION: The aim of this study is to report our clinical hemodialysis experience using a percutaneous arteriovenous fistula (pAVF) created with the Ellipsys® vascular access system. This pAVF device creates a permanent AVF anastomosis between the proximal radial artery (PRA) and the deep communicating vein (DCV) in the proximal forearm. METHODS: The medical records of all patients with a pAVF were retrospectively reviewed. The clinical data analyzed included reliability of pAVF use, quality of dialysis, rate and success of puncture, and pAVF related complications, along with incidence of subsequent interventions. FINDINGS: Between May 2017 and November 2018, 34 patients had a pAVF created with technical success in 33 patients (97%). Twenty-eight out of 34 (82%) patients had successful two-needle cannulation within 10 days to 6 weeks after pAVF creation. The mean Kt/v was 1.6 (1.2-2) and the average recirculation was 10%. Fifteen patients (44%) needed no further access intervention. Twelve patients (35%) required an additional procedure to assist maturation of the pAVF in order to facilitate puncture. The average blood flow measured at the brachial artery, before the first cannulation, was 850 ml/min. From causes unrelated to the procedure, four patients died during the follow-up study. Two patients required revision to a surgical AVF. None of the pAVFs developed aneurysmal degeneration steal syndrome, or high access flow related issues. DISCUSSION: The Ellipsys® pAVF offers a safe and functional vascular access for hemodialysis. Advantages included prompt access maturation, avoidance of high flow AVFs, and a simple nonsurgical procedure with high patient satisfaction. Functional outcomes are equivalent and likely better than surgical fistulas. There appears to be less aneurysmal degeneration and need for future re-intervention. Objective dialysis parameters indicate excellent quality of hemodialysis for the patient.

Arterio-venous fistula for automated red blood cells exchange in patients with sickle cell disease: Complications and outcomes.

Erythrocytapheresis (ER) can improve outcome in patients with sickle cell disease (SCD). A good vascular access is required but frequently it can be difficult to obtain for sickle cell patients. Arterio-venous fistulas (AVFs) have been suggested for ER in SCD supported by limited evidence. We report the largest cohort of ER performed with AVFs from three French SCD reference centers. Data of SCD patients undergoing ER with AVFs in the French SCD reference center were retrospectively collected. The inclusion criteria were: SS or Sß-Thalassemia and AVF surgery for ER. SCD-related complications, transfusion history, details about AVF surgical procedure, echocardiographic data before and after AVF, AVF-related surgical and hemodynamical complications were collected. Twenty-six patients (mean age 20.5 years, mean follow-up 68 months [11-279]) were included. Twenty-three patients (88.5%) required central vascular access before AVF. Fifteen AVFs (58%) were created on the forearm and 11 (42%) on the arm. Nineteen patients (73%) had stenotic, thrombotic or infectious AVF complications. A total of 0.36 stenosis per 1,000 AVF days, 0.37 thrombosis per 1,000 AVF days and 0.078 infections per 1.000 AVF days were observed. The mean AVF lifespan was 51 months [13-218]. One patient with severe pulmonary hypertension worsened after AVF creation and died. We report the first series of SCD patients with AVF for ER, demonstrating that AVFs could be considered as a potential vascular access for ER. Patients with increased risk for hemodynamic intolerance of AVFs must be carefully identified, so that alternative vascular accesses can be considered. Am. J. Hematol. 92:136-140, 2017. © 2016 Wiley Periodicals, Inc.

Videogames and Therapy: A Narrative Review of Recent Publication and Application to Treatment.

Individuals who play videogames can interact with virtual worlds, resulting in emotional and intellectual connections that have therapeutic implications in the hands of a skilled and informed therapist. There is research available in the literature that suggests that videogames are a viable option in psychotherapy. The present article provides a review of the literature available in the use of videogames in treatment, discusses the importance of disseminating the findings in the literature, and discusses the integration of videogames in treatment.

Long-term results of femoral vein transposition for autogenous arteriovenous hemodialysis access.

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.

Placement of wrist ulnar-basilic autogenous arteriovenous access for hemodialysis in adults and children using microsurgery.

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.

Lipectomy as a new approach to secondary procedure superficialization of direct autogenous forearm radial-cephalic arteriovenous accesses for hemodialysis.

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/m(2). 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.

Low-flow maturation failure of distal accesses: Treatment by angioplasty of forearm arteries.

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.

Transposition of radial artery for reduction of excessive high-flow in autogenous arm accesses for hemodialysis.

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.