Native Fistula Research Articles

Validation of arteriovenous access stage (AVAS) classification: a prospective, international multicentre study.

The arteriovenous access stage (AVAS) classification provides evaluation of upper extremity vessels for vascular access (VA) suitability. It divides patients into classes within three main groups: suitable for native fistula (AVAS1) or prosthetic graft (AVAS2), and patients not suitable for conventional native or prosthetic VA (AVAS3). We validated this system on a prospective dataset. A prospective, international observational study (NCT04796558) involved 11 centres from 8 countries. Patient recruitment was from March 2021 to January 2024. Demographic data, risk factors, vessels parameters, VA types, AVAS class and early VA failure were collected. Percentage agreement was used to assess predictive ability of AVAS (comparison of AVAS and created VA) and consistency of AVAS assessment between evaluators. Pearson's Chi-squared test was used for comparison of early failure rate of conventional (predicted by AVAS) and unconventional (not predicted by AVAS) VA. From 1034 enrolled patients, 935 had arteriovenous fistula or graft, 99 patients did not undergo VA creation due opting for alternative renal replacement therapies, experiencing health complications, death or non-compliance. AVAS1 had 91.2%, AVAS2 7.2% and AVAS3 1.6% of patients. Agreement between evaluators was 89%. The most frequently created VAs were radial-cephalic (46%) and brachial-cephalic (27%) fistulae. The accuracy of AVAS versus created access was 79%. In comparison, VA predicted by clinicians versus created access was 62.1%. Inaccuracy of AVAS prediction was more common with higher AVAS classes, and the most common reason for inaccuracy was creation of distal VA despite less favourable anatomy (17%). Patients with unconventional VA had higher early failure rate than patients with conventional VA (20% vs 9.3%, respectively, P=.002). AVAS is effective in predicting VA creation, but overall accuracy is reduced at higher AVAS classes when the complexity of decision-making increases and proximal vessels require preservation. When AVAS was followed by clinicians, early failure was significantly decreased.

#2826 The Charlson Comorbidity Index in Registry-Based Research for Survival of Vascular Access

Abstract Background and Aims Several studies have reported higher haemodialysis survival in women; however, the influence of gender on arteriovenous fistula survival has not been extensively studied. For this reason, our aim is to estimate the prevalence of arteriovenous fistulae according to gender, adjusted by the Charlson comorbidity index. Method Retrospective study in patients on haemodialysis programme, by consulting electronic records over a period of 35 months. Demographic variables, primary and secondary patency events were included. The population was categorised on the basis of the Charlson Index and gender. Statistical analysis was performed using Kaplan Meyer survival curves to contrast the impact of comorbidities on the different patency events. Results 52 patients were evaluated, with a mean age of 70.7 ± 1.57 years, 69.2% men, 30.8% women, 42.3% diabetic, Charlson with a median of 7 (6.5 - 7.73), 98.1% had a native fistula, being more frequent the location in the humeral head (63.5%) and predominantly in the left upper limb (65.4% ). 21.2% of patients required some intervention on their AVF. The time required to achieve an event in both primary patency and secondary patency was longer in patients with a Charlson Index less than or equal to 7, and this was statistically significant (Log Rank Test (Mantel-Cox): primary patency p=0.003 and secondary patency p=0.002). In the group of women with a Charlson comorbidity index less than or equal to 7, mean survival for primary and secondary patency was even higher than in all patients, with statistical significance (Log Rank Test (Mantel-Cox ): primary patency p=0.005 and secondary patency p=0.008), a situation not repeated in men where no significant differences in survival were found when analysed according to the Charlson index. Conclusion The Charlson index in our population is a significant factor in the survival of AVFs in women.

#2778 The Charlson Index can be used prospectively to identify patients who will need a close follow up of surveillance for the vascular access

Abstract Background and Aims The primary screening methods for monitoring vascular access in haemodialysis involve measuring access blood flow and dialysis venous pressure. However, challenges are present in both aspects, potentially hindering the attainment of desired results. Research in this field is crucial to identify the optimal combination of intensive clinical monitoring and supplementary surveillance for effective outcomes. For this reason, we aim to describe the impact of comorbidities and patency of native arteriovenous fistulae (nAVF). Method Descriptive study of prevalent patients on haemodialysis, carried out by consulting electronic medical records over a period of 35 months. Demographic and vascular access-related variables were included. Primary and secondary patency was calculated for all accesses. Patients with upper limb AVF were classified according to distal and proximal access location; and the Charlson Index was used to categorise patients according to comorbidities. Kaplan Meyer survival curves were used to contrast the impact of comorbidities on the different patency. Results 52 patients, age 70.7 ± 1.57 years, 69.2% male, 42.3% diabetic, Charlson index with a median of 7 (6.5 - 7.73), 98.1% with a native fistula, the most frequent nAVF location in our population was humerocephalic (63.5%) and a predominance of the left upper extremity (65.4%). According to the location of the access, adjusted by the Charlson index, it is evident that in proximal accesses (humerocephalic and basilic humerus nAVF), with a Charlson Index less than or equal to 7, the time required to reach an event was statistically significantly longer (Log Rank Test (Mantel-Cox): primary patency p=0.057 and secondary patency p=0.069). This comparison was not significant in distal fistulas. Conclusion Using the Charlson comorbidity index information, we transformed it into an accessible and valuable tool for maintaining vascular access patency. Close follow-up in patients with proximal nAVF and high Charlson comorbidity index could be beneficial.

#2833 Charlson comorbidity index predicts early failure and overall survival of vascular access among diabetic dialysis patients.

Abstract Background and Aims Vascular access (VA) survival is a determinant factor in the morbidity and mortality of haemodialysis patients, directly influencing their quality of life. Some studies have described the influence of diabetes on the reduced survival of arteriovenous fistulas as an independent factor; however, the correlation between other comorbidities in diabetic patients with vascular access survival has been less well documented. Therefore, our aim is to describe the relationship between comorbidities in diabetic haemodialysis patients and arteriovenous fistula (AVF) patency. Method Descriptive, observational and retrospective study in prevalent patients included in a haemodialysis programme by consulting electronic records over a period of 35 months. Demographic variables; related to vascular access and primary and secondary patency of all accesses were included. The Charlson Comorbidity Index was used to categorise diabetic patients according to comorbidities. Kaplan Meyer survival curves were used to contrast the impact of comorbidities on the different patency. Results 22 patients, mean age 68.36 ± 10.9 years, 68.18% male, 31.82% female, Charlson index with a median of 6.5 (5 - 8), 95.45% had a native fistula, with humero-cephalic location being more frequent (72.72%) and predominance of the left upper arm (68.18%). The time required to reach an event in both primary patency and secondary patency in diabetic patients was longer in patients with a Charlson index less than or equal to 7, this being statistically significant (Log Rank Test (Mantel-Cox): primary patency p=0.022 and secondary patency p=0.032). Conclusion The Charlson Comorbidity Index in our population is a significant factor in arteriovenous fistula survival.

Zero upper arm hemodialysis fistulas: utopian or realistic goal?

Although distal native fistula is the best first-line vascular access (VA), upper arm fistula (UAF) prevalence is increasing worldwide, except in Japan. Our previous survey on 50% of hemodialysis patients (HP) revealed a prevalence of UAF of less than 5%, which is lower than the findings published by the DOPPS 5 study in our country. We analyzed the VA prevalence on 100% of HPs from our department. In December 2021, we investigated the prevalence of vascular access of 1295 hemodialysis patients from 17 dialysis factories. VAs were classified according to location into distal forearm fistula (DFF), middle-proximal forearm fistula (MPFF), and UAF. The department manages VA using a Hub and Spoke model. The hub performs simple and complex VA including Graft placement, the Percutaneous Transluminal Angioplasty (PTA) of fistulas and central stenosis, and the surgical and endovascular rescue of thrombosed or stenotic fistulas. The spokes perform mainly simple DFFs. The mean age of 1295 HP (35% females and 21% diabetics) was 69 ± 12.4 years; 506 (39%) were over 75 years old. The prevalence of DFF, MPFF, UAF, GRAFT, and CVC was 63.5%, 10.1%, 3%, 0.7%, and 22.5%, respectively. Data comparison between our two surveys revealed a lower MPFF, UAF, and GRAFT prevalence and increased CVC prevalence. Patients aged 75 years or older, women, and diabetics showed a higher frequency of CVC and a lower prevalence of DFF. The findings confirm the low prevalence of UAF found in our prior survey, demonstrating that UAFs can be reduced to 5% or less, as seen in Japanese experience.

Initial experience of thrombectomy using vascular snare with multiple loops for chronic organized thrombi in patients with thrombosed native hemodialysis fistulas.

Thrombi in native hemodialysis access frequently exhibit chronic organized feature because they have formed over a long period. Removal of these is quite difficult owing to relatively large volume, resilient feature, limitations of the introducer sheath size, etc. In this study, we report our experience using a vascular snare for the removal of these thrombi in native arteriovenous fistula (AVF). The medical records of patients who underwent recanalization for thrombosed AVFs from January 2019 to August 2023 were reviewed. During the study period, a total of 29 native fistulas (19 brachiocephalic, nine radiocephalic, and one radiobasilic) in 25 patients were treated using a vascular snare with multiple loops (19 men and six women). Characteristics of the AVFs, endovascular procedures, technical and clinical results, and complications were evaluated. Anatomic and clinical success rates were 96.6% and 100%, respectively. Total thrombosis was observed in 21 (72.4%) fistulas. Aneurysmal changes were found in 22 (75.9%) fistulas. The mean fistula age at the time of the procedure was 60.9 months (standard deviation, 52.2). Thrombectomy was initiated using a vascular snare in 14 fistulas. In 15 fistulas for which the procedures were initiated using a rotational percutaneous thrombectomy device (PTD), a vascular snare was subsequently used because recanalization failed or was insufficient due to chronic organizing thrombi. Additional aspiration and balloon angioplasty were performed in 27 (93.1%) and 28 (96.6%), respectively. Pharmacological thrombolysis was performed in one fistula for long segmental thrombosis combined with arterial thrombosis. The mean procedure time, excluding thrombolysis, was 91.9 min (standard deviation, 55.5). No complications related to the use of the vascular snare was observed. The use of a vascular snare with multiple loops was safe and highly effective for the removal of chronic organized thrombi in the recanalization of thrombosed AVFs.

Salvage of Mega-fistula with Nezakatgoo Technique

Introduction: Mega-fistula is understood as an arteriovenous fistula that is very dilated throughout its course, tortuous, sometimes aneurysmal, and that presents flows above 2L/min; this carries the risk of generating multiple complications (from aneurysmal rupture, recirculation, and heart failure due to overload, among others). Its usual treatment is ligation or prosthetic replacement. Material and methods: The technique described by Nezakatgoo et al. was performed on three patients with mega fistulas (operated between 2020 and 2023) in whom salvage surgery and recovery of the entire fistula was performed. Complete dissection of the fistula from its anastomosis to the arch of the cephalic vein is performed, the vein is calibrated with a 24-34 Fr chest tube, and the excess of the mega-fistula and aneurysms are resected. In the case of stenotic areas, these are enlarged, or new anastomoses are made, and in the case of stenosis of the arch, a new anastomosis is made in the axillary vein. Results: The first case describes a left humerocephalic fistula made in 2011, which, after the plastic surgery, required two angioplasties due to stenosis in the middle third (at 125 and 236 days after the plastic surgery). It remains patent, with a total patency of 156 months since its initial confection and 36 months since the plastic. The second patient presents a mega-fistula performed in April 2019, which, after plastic surgery, required angioplasty for stenosis at one time at 509 days and continues to be permeable to date, with a total patency of 56 months and 30 months since plastic. The third fistula was operated in the context of total fistula thrombosis and required, in the first instance, a thrombectomy prior to reconstruction. It evolved in two episodes (at months 2 and 5), with stage IIb steal treated by banding (Miller technique) on both occasions. It presents a total patency of 57 m and 18 m from the plastic. All patients remain on dialysis to date due to the reconstructed fistula. Conclusions: Salvage of mega-fistula is a valid procedure to continue the useful life of native fistulas in the short and medium term; if necessary, complementary procedures are required to solve problems similar to those of other fistulas.

Multicenter Randomized Controlled Trial of APERTO-Paclitaxel Drug-Eluting Balloon Angioplasty Versus Standard Percutaneous Transluminal Angioplasty in Dysfunctional Hemodialysis Grafts and Native Fistulae.

to assess the safety and efficacy of APERTO-Paclitaxel-coated balloon angioplasty versus standard angioplasty for the treatment of dysfunctional hemodialysis shunts and native arteriovenous fistulae. consecutive patients with dysfunctional dialysis related to underlying efferent vein stenosis were included and randomized 1:1 to either APERTO-paclitaxel drug-coated balloon (study arm) or standard percutaneous transluminal angioplasty (control arm). Primary endpoint is time from treatment until dialysis access dysfunction according to standardized Kidney Disease Outcomes Quality Initiative (KDOQI)-guidelines and assessed by Kaplan-Meier survival curves and tested for significance with log-rank analysis. Secondary endpoints include device, technical, and clinical success of the index angioplasty procedure. The study included 103 patients (n=51 study-group) with a de novo (n=33) dysfunctional native arteriovenous fistula (n=79) in the forearm (n=60). The majority of included patients were male with a mean age of 69.8 years, presenting with a dysfunctioning autologous arteriovenous fistula in the forearm. Device-related complications did not occur in any of the included patients. Functional hemodialysis access without need for re-intervention at 1 year after index procedure was found in n=10 (19.6%) and n=5 (9.6%) of patients treated with, respectively, paclitaxel drug-coated balloon and percutaneous transluminal angioplasty (p=0.612). A nonsignificant benefit of paclitaxel drug-coated balloon (n=5; 25%) over percutaneous transluminal angioplasty (n=1; 11%) was found (p=0.953) in de novo lesions in autologous fistulas. APERTO-paclitaxel drug-coated balloon is a safe balloon catheter to manage dysfunctional hemodialysis access; however, longer period of adequate hemodialysis circuit functioning after endovascular index stenosis treatment, using APERTO-paclitaxel drug-coated balloon versus percutaneous transluminal angioplasty could not be demonstrated. APERTO-paclitaxel drug-coated balloon catheter is a safe device to manage dysfunctional hemodialysis access. Compared to conventional angioplasty balloon, the APERTO drug-coated balloon will not result in longer period of adequate hemodialysis circuit functioning. A non-significant benefit of APERTO drug-coated balloon was found in de novo lesions in autologous fistulas.

Oscillometric pulse wave analysis for detecting low flow arteriovenous fistula

BackgroundPulse wave analysis may be useful to assess fistula function. We aimed to prospectively evaluate if convenient oscillometric devices are applicable to detect flow below 500 ml/min in a real life clinical setting.MethodsPulse waves were recorded ambilaterally with the vicorder® device at the brachial artery in 53 patients on haemodialysis with native fistula. Primary variables consisted of the mean slope between the systolic maximum and the diacrotic notch (Slope2), the sum of the mean slopes in the four characteristic sections of pulse waves (Slope∑) and the amplitude of relative volumetric change in the measuring cuff at the upper arm (AMP). Fistula flow was measured with the use of duplex sonography using a standardized approach.ResultsParameter values above or below the median indicated measurement at the non-fistula side, with sensitivities/specificities of 0.79/0.79 (p < 0.001) for Slope 2, 0.64/0.64 (p = 0.003) for Slope∑ and 0.81/0.81 (p < 0.001) for AMP if measurements at the fistula and non-fistula arm were considered. ROC-analyses of parameter values measured at the fistula to detect low flow demonstrated AUCs (with CI) of 0.652 (0.437–0.866, p = 0.167) for Slope2, 0.732 (0.566–0.899, p = 0.006) for Slope∑ and 0.775 (0.56–0.991, p = 0.012) for AMP. The point with maximal youden’s index was regarded as optimal cut-off, which corresponded to sensitivities and specificities of 0.8/0.56 for slope2, 0.86/ 0.56 for Slope∑ and 0.93/0.78 for AMP.ConclusionFunctional surveillance with oscillometry is a promising clinical application to detect a low fistula flow. Among all investigated pulse wave parameters AMP revealed the highest diagnostic accuracy.Graphical

#2787 HOSPITAL MANAGEMENT OF AN INTEGRATED CLINICAL PRACTICE UNIT OF VASCULAR ACCESS FOR HEMODIALYSIS: A CHALLENGE FOR IMPROVING HEALTHCARE QUALITY?

Abstract Background and Aims Vascular access (VA) for haemodialysis (HD) is essential for renal patients due to its high morbimortality and economic cost. Integrated Clinical Practice Units (ICPU) allows health organizations to establish comprehensive care, improve the quality and safety of care processes, as well as favor the accessibility of health care. The VA multidisciplinary teams for HD are crucial in the proper management of VA, although their implementation in daily clinical practice is not fully consolidated. The aim of this study was to analyze the effectiveness of the healthcare processess in patients with VA for HD after the creation of our ICPU focused in the multidisciplinary management of the VA (FUVA) through quality of care indicators. Method 12 years retrospective unicentric study analyzed in two periods: first period (2010-2015) and second period (2016-22) after FUVA creation. The indicators include sociodemographic data, processes activities (first and successive visits, endovascular procedures, type and number of surgical interventions, delayed time for interventions, mean hospitalitation stay, and results oriented to the patient's quality of life (VA initial assessment and dysfunction, inpatient and outpatient VA interventions). Results 551 VA for HD hospital admissions r were performed (53.2% in charge of nephrology, with 893 total days of stay and mean stay of 3.6 days), 670 surgical interventions (69.7% native fistulas, 47.3% admitted, 37±9.7 days of surgical delay) and 320 endovascular procedures (28.1% admitted, 11 ± 1.2 days delay). After the creation of the ICPU (FUVA), a total of 631 visits (96% first visit) were made in 451 patients with mean age 65.7 ± 17.5 years (66% men), 495 VA Doppler ultrasounds, 287 HD catheter placements (54.1% permanent, 29.2% left) and 84 withdrawals. Similarly, in this period there was a decrease in the number (160 vs 130) and percentage (92.4 vs 34.3%) of VA for HD admissions, a shorter surgical delay time (39 ± 9.3 vs 32 ± 9.1 days) and a reduction in the mean hospital stay (3.7 vs 2.9 days), respectively. Similarly, outpatient management of all endovascular procedures performed (187) was achieved without repercussion on the waiting time for the procedure (11 ± 0.9). Conclusion In our study, the hospital management of VA for HD through the creation of an UPCI, allowed a more efficient management of the available care resources through the continuity of care of the process, favoring the integral and integrated care of the patient as well as contributing to the improvement in the management and survival of VA for HD. Similarly, elaboration and analysis of helathcare indicators have been useful tools in the evaluation of the quality of healthcare of our vascular access unit.

#4430 PREVALENCE OF AMPUTATION IN HD PATIENTS: A DIALYSIS PROGRAM WITHOUT SOCKS

Abstract Background and Aims Peripheral arterial disease affects very commonly CKD patients on dialysis. Frequently such injuries precede severe complications that lead to hospitalizations, amputations and even death. Objectives: Study the prevalence of ulcers and amputation on dialysis, analyze related risk factors, post-surgical results and establish a prevention program. Method Descriptive, observational, retrospective (7 years), single-center study in patients with CKD on dialysis. Results 202 patients (12 PD 190 HD), 67 active and 135 off dialysis, 127 men 75 women. Average age 69 years. Average time on dialysis 47 months. Vascular access: 56%, native fistula 37% catheter 7% prosthesis. Cause CKD 30,2% ND, 22.8% NAS. 95.54% HBP, 46.53% DM 26.73% Ischemic heart disease, 31.19% chronic ischemia, 26.24% had intermittent claudication, 12.38 % had all the comorbidities indicated. Higher comorbidity in males M:F 4:1. 53.47% ex-smokers or active habit. Ulcers 29.7% (40 men 20 women), 76.67%, diabetics. Half of the patients with DM (48.94%) presented ulcers. The most frequent was vascular ulcer (43.67%) followed by that associated with diabetic foot (26.67%) and pressure ulcer 15%. Amputations (11 major and 13 minor) in 24 patients (16 men 8 women) with a prevalence: overall 12%, DM 22.34%, with ulcers 40% and 46% if they are diabetics. Analytics in amputees. Average: PTH 352 ng/dl, Phosphorus 4.4 mg/dl, Vitamin D 19 mg/dl, Albumin 3.3g/dl, hypercholesterolemia in 20%. 17 patients with chronic ischemia were revascularized (76.47% ended in amputation). Mortality: 88 patients died (43.56%), of which 41 were patients with ulcers (68.33%) and 20 were amputees (83.33%, 3 early mortality and 17 late mortality). Conclusion The prevalence of amputations on dialysis is high. Most are male, DM with high cardiovascular comorbidity and a previous history of ulcers. Mortality increases in patients with CKDG5D with ulcers and amputees. There is a need for 11dialysis without socks” programs for early detection of dialysis ulcers to reduce the incidence of amputees.

#5446 A COHORT OF DIALYSIS PATIENTS WITH LOW PREVALENCE OF UPPER ARM FISTULAS

Abstract Background and Aims International guidelines encourage the use of distal native fistula (AVF) which is the best first-line vascular access (VA). But, despite these indications, all over the world, except for Japan, the prevalence of upper arm fistula (UAF) is dramatically increasing. Previous surveys in our department included about 50% of Haemodialysis patients (HP) and showed prevalence of UAFs less then 5%–very low, if compared with those of our country, reported by DOPPS 5 study. We decided to analyse 100% of HP in our department, in order to confirm or exclude the low prevalence of UAF. Method Puglia, southern east of Italy, has 1.4 millions inhabitants, of which 1365 need dialysis; 1295 on haemodialysis in 17 different centers and 70 on peritoneal dialysis. The department is organized on a Hub and Spoke model for VA management (Fig. 1). Hub performs simple and complex AVFs, Graft, PTA of non matured or stenotic fistulas, PTA of central stenosis, and surgical rescue of thrombosed or stenotic fistulas. Our four spokes perform mainly simple distal forearm fistula (DFF). In December 2021 we collected datas of VA prevalence of all 1295 HP. The AVFs were classified, according to their anatomical site, in DFF, mean-proximal forearm fistula (MPFF) and UAF. Results The average age of 1295 HP was 69 ± 14,65% yo (65% males and 21% diabetics) and 458 of them (35%) where more than 75 yo. The prevalence of DFF, MPFF, UAF, GRAFT and CVC was 63.5%, 10.1%, 3%, 0.7%, 22.5% respectively (fig. 2). Patients aged ≥75 years, women and diabetics showed a higher prevalence of CVC and a lower prevalence of DFF. Conclusion Data collected on all patients confirm the low prevalence of UAF detected in the previous surveys -which involved only a part of haemodialysis patients. Zero upper arm fistulas is an utopian goal, but it seems possible to reduce the prevalence of proximal fistulas to 5% or less as the Japanese experience has showed.

Role of stenting for maintenance of the extremity fistula/graft overview.

Dialysis access interventions have undergone significant developments over the last few decades. Angioplasty has been the mainstay of therapy since the early interventions in the 1980s and 1990s, but poor long-term patency and early loss of access has led investigators to assess other devices to treat stenoses associated with dialysis access failure. Multiple retrospective studies of stents for treatment of stenoses that did not respond to angioplasty demonstrated that the long-term outcomes were not improved over angioplasty alone. Cutting balloons have been studied in a prospective randomized fashion but also showed no long-term improvement over angioplasty alone. Prospective randomized trials have demonstrated that stent-grafts have superior primary patency of the access and the target lesions than angioplasty. The purpose of this review is to summarize the current state of knowledge regarding stent and stent graft use in dialysis access failure. We will discuss the early observational data related to stent use in dialysis access failure including the earliest reports of stent use in dialysis access failure. This review will then focus the review on the prospective randomized data that supports the use of stent-grafts in specific areas of access failure. These include venous outflow stenosis related to grafts, cephalic arch stenoses, native fistula intervention, and the use of stent-grafts to revise in-stent restenosis. Each of these applications will be summarized and the current status of the data will be reviewed.

Outpatient use of tPA to recanalize thrombosed native fistulas a case series and discussion of literature

Background: The present study aims to evaluate the effectiveness of ultrasound-guided percutaneous alteplase (t-PA) injection for the treatment of long segment ( ≥14cm) thrombi in the efferent veins of native arteriovenous fistulas in hemodialysis patients. Methods: A total of 9 patients who underwent t-PA application under ultrasound guidance in the interventional radiology clinic between 2019 and 2021 were included in the study. During the intervention, information such as thrombosed segment length, t-PA dose, number of sessions, presence of aneurysmal segment, bleeding after the intervention and the need for percutaneous transluminal angioplasty (PTA) were recorded. Restoring the flow in the fistula was considered the successful outcome. All statistical evaluations were performed with the IBM SPSS Statistics 21 software (version 21.0; SPSS Inc, Chicago, Illinois) for Windows. Results: Mean age of the patients was 48.7±14 years, the fistula age was 28.7±11 months, the thrombosis age was 3.5±2 days, and the thrombosed segment length was 17.7±2.9 cm. Post-intervention bleeding that did not require treatment was encountered in 2 patients, and stenosis in the proximal fistula was encountered in 6 patients. PTA was applied to 7 patients after t-PA. After the interventions, effective flow was provided in all patients. Conclusion: Ultrasound-guided percutaneous t-PA injection should be considered as an effective intervention which is less invasive, can be performed as an outpatient intervention and has fewer complications, even if the thrombi segments are long (&gt;10 cm). This technique avoids the potential endothelial damage and saves the cost of the mechanical devices.

Anévrisme de l’artère brachiale chez un patient transplanté rénal après fermeture de fistule distale

Brachial artery aneurysmal degeneration is an exceptional complication of distal native fistulas. Chronic mechanical stresses due to high flow, as well as immunosuppressants drugs following renal transplantation, are the mains factors implicated in the pathophysiological mechanism. We report a case of a transplant patient with a true, symptomatic, brachial artery aneurysm, 8 years after transplantation and 5 years after radiocephalic wrist fistula ligation. The patient underwent open surgical repair, with aneurysm resection and end-to-end anastomosis. We present a literature review of the different therapeutic strategies of this unusual entity.

FC 101: The Impact of Vascular Access Types on Survival in Hemodialysis: Time for a Shift in Paradigm? A Prospective Cohort Study

Abstract BACKGROUND AND AIMS Despite arteriovenous native fistula (AVF) is the vascular access (VA) of choice due to a better outcome than central venous catheter (CVC) [1], catheter use is still common among haemodialysis (HD) patients. Our study aims to describe the survival and epidemiological features of a cohort of dialysis patients with a focus on the role of VA type. METHOD Our cohort comprises a prospective follow-up conduced from 2001 to 2020, which led to recruit 754 patients in HD. We identified a subgroup of patients survived less than 7 months (n 124) and a subgroup of patients survived more or equal than 7 months and up to 60 months (n = 472). In addition to this, every subgroup was subdivided into two different age groups, including patients of age ≤74 years old and those ≥75 years old. Other analysed characteristics were demographic features and baseline clinical data, like primary cause of ESKD, co-morbidities at the beginning of the HD treatment and type of VA both at start of HD and at the end of the follow-up. Starting HD without planning, namely being ‘late referral’, was also considered. Descriptive analysis was performed on baseline data. Moreover, we analysed predictive variables of death for any cause with Univariate and Multivariate Logistic Regression. Predictors of survival were analysed through univariate and multivariate Cox regression. RESULTS At the multivariate logistic regression, the use of tunnelled CVC at the start of HD resulted protective against death from any cause (aOR, 0.43; P = 0.017) in the whole cohort (n = 754). In the subgroup analysis of patients (n = 124) with a follow-up &amp;lt; 7 months, malignancy (aOR, 4.57; P = 0.002), severe cardiomyopathy (aOR, 4.35; P = 0.001) and vascular disease (aOR, 3.22; P = 0.008) were estimated as significantly predictors of death. At the multivariate Cox analysis, being ‘late referral’ was associated with decreased survival within 6 months (aHR, 3.79; P = 0.001). In the subgroup of elderly (≥75 years old; n = 201/472) survived within 7–60 months, multivariate logistic regression showed that the use of tunnelled CVC at the start of HD (Figure 1) resulted even more protective against death (aOR 0.25; P = 0.021). Moreover, vascular disease resulted as the main risk factor for death (aOR 5.11; P = 0.000), and it was confirmed as the only independent risk factor at the COX analysis (aHR 1.58; P = 0.017; see Figure 2). CONCLUSION Vascular disease is the main risk factor for death in haemodialysis patients. Furthermore, cardiovascular disease influences patient outcome more than the VA type, confirming the assumption that the choice of VA might be influenced by several issues as age and comorbidities [2, 3]. In the short-term survival subgroup, neither VA nor age emerged to be predictor of mortality, suggesting that health status before starting maintenance HD might explain an important part of the risk often attributed to catheter use.[4] Moreover, starting RRT without proper planning (‘late referral’) was extremely relevant in determining short-term survival. Tunnelled CVC might be the option of choice as VA, specifically in the elderly with vascular disease. In conclusion, our long-term experience suggests that the choice of VA should not necessarily follow the ‘fistula first’ approach, but it should be based on dialytic life expectancy and comorbidities.

MO765: Should We have to Create A Proximal Fistula in First Instance for Patients ≥75 Years Old?

Abstract BACKGROUND In France, the Network Epidemiology and Information in Nephrology evaluated the incidence of cases of chronic end-stage renal disease (ESRD), treated by dialysis, of patients aged ≥75 years at 39.8% (2015). Timely placement and development of functional fistulas for haemodialysis remain difficult logistical problems along with their high failure rate. Cardiovascular (CV) morbidity-mortality increases when patients initiate catheter-based treatment. The recommendations call for a glomerular filtration rate (GFR) between 15 and 30 mL/min/1.73m² (EBPG 2007 and Canadian 2006) to implement a fistula. The older the patients, the more the quality of the venous network deteriorates. In this population, clinicians face a simple problem: creating a too early fistula and preparing patients for an adequate supply. The surgery of vascular approaches tries to avoid two pitfalls: ‘too much to preserve’ the vascular capital, ‘too much to privilege’ the permeability of the first by creating proximal approaches (Barrou B.). The guidelines [Kidney Disease Outcomes Quality Initiative (K/DOQI) 2006] recommend the most distal vascular approach possible. Since 2016, CKD patients aged ≥75 years, have been implanted with arteriovenous fistula (native or prosthetic), localized in the first line of the humero-cephalic vein, huméro-basilique, or humero-axillary. Our primary objective is to assess primary permeability in a population of patients aged ≥75 years with stage IV/V chronic kidney disease (CKD) after the first-line proximal fistula. METHOD All patients aged ≥75 years for which a first-line proximal VA was created between 1 January 2016 and 31 December 2019 have been retrospectively reviewed in an observational study. They were followed for 12 months. A quarterly compilation of data has been produced. RESULTS A total of 31 patients (74% of men) benefit from the creation of a native fistula (90.3%) or prosthetic. During follow-up, 8 patients were excluded. 29% of patients had started catheter haemodialysis treatment prior to the creation of their first fistula. A total of 7 changed fistula from initial surgery during the study, of which 2 after the first use. At the creation of the vascular access, the median age of patients is 81 years, of which 35.5% have vascular nephropathy and 19.4% have diabetic nephropathy. The location of the anastomosis is as follows: 84% FAV brachiocephalic, 10% FAV brachiobasilic and 6% FAV axillary. At 12 months, 16 patients were still under observation. A total of 5 patients had thrombosis of their VA (80% of native fistulas). The average interval between the creation of the first, and the thrombosis is 2.18 months. Patients dialyzed with VA were 68%. On a scale from 0 (no difficulty) to 10 (puncture not performed), the average difficulty score of the first puncture is 2.2. The average time in the day between the first puncture and first ‘effective’ dialysis on the first 13.9 days and the average weekly duration of dialysis at the first effective puncture is 11.29 hours. There are 28 hospitalizations, 21% of which are related to VA, 37 ultrasound, 9 angiography and 4 surgical repairs were performed on VA. Only one ischaemia of the hand is observed, treated medically. Estimates of the risk of thrombosis associated with diabetes are confirmed [P = 0.02; 95% confidence interval (95%CI); hazard ratio (HR): 0.054–0.332]. At 12 months, 94% of the surroundings are permeable without any thrombosis. CONCLUSION This study confirms the interest in a proximal vascular approach in people aged ≥75. We have voluntarily included patients from the creation of their VA and for the majority before the time of starting haemodialysis. The average age is high in a high-risk epidemiological context (HTA, diabetes) and the number of early deaths (16%). The quality of the surroundings is confirmed by the percentage of native fistula at nearly 90% in accordance with the guidelines. The surgical team is motivated and sensitized in this collaborative project. A total of 52% of patients remained in observation at M12 and 94% had a permeable first with satisfactory dialysis quality. These results are encouraging and require a broader multicentre prospective and comparative study like other problems in managing vascular access for haemodialysis.

Salvage of infected autogenous arteriovenous fistulas, is it possible?

Infection in autogenous arteriovenous fistulas (AVFs) is a critical situation in patients with end stage renal disease (ESRD) that can lead to life threatening rupture or septicemia. To date, no standard guidelines regarding the surgical repair of the infected AVFs is available. To evaluate the safety and efficacy of the surgical repair in the infected autogenous AVFs. This prospective study involved 64 ESRD patients who presented with infected autogenous AVFs. Repair of the infected autogenous AVFs was done in 50 cases, while ligation was needed in the other 14 cases. Aneurysmorrhaphy was done in the 26 cases of puncture site infection over venous aneurysms. In 20 cases of AVFs with anastomotic disruption, higher recreation in a proximal clean field (AVF loop anastomosis) was performed, while abscess drainage was done in the remaining four cases presented with non-communicating abscess over the vein. The 14 cases of ligated AVFs included 9 cases of infected ruptured AVFs with active bleeding and 4 cases with non-reconstructable puncture site infection. After 1 year of follow up, 41 cases (82%) of the repaired AVFs (n = 50) remained patent and functioning as re-infection occurred in 9 cases. Six tunneled permanent catheters were implanted in the 14 cases with ligated AVFs, while the remaining 8 cases had new AVFs established (7 cases of them retained patent AVFs during the follow up period). Surgical repair of the infected AVFs is an effective procedure that achieves many goals, such as saving patients' lives, maintaining the patency of the native fistula, and avoidance of creation of new AVFs in another site with exhaustion the available veins.

Faux anévrisme compressif de l’artère brachiale chez un hémodialysé : toujours superficialiser la veine basilique du bras !

The creation and preservation of vascular accesses, in patients with end-stage renal failure, remains a challenge for nephrologists and vascular surgeons. Native fistula is the best vascular access, humeral-basilic fistula is a precious access in patients who have exhausted their venous capital in the forearm and in whom the cephalic vein of the arm is small or damaged. Given its deep location, any puncture of this vein is prohibited before its superficialization, even if it is of good caliber, because it can have dramatic consequences, in particular the loss of the limb or even death. We report the case of a patient undergoing hemodialysis for seven years with a non-superficialized humeral-basilic fistula, admitted for an iatrogenic false aneurysm of the brachial artery following a puncture for dialysis, with compression of the median nerve, treated surgically.

Multifrecuency bioimpedance phase angle as a tool to predict maturation failure of native fistulae for hemodialysis

Background and objectives: An arteriovenous fistula is considered to be an ideal vascular access for patients receiving hemodialysis, its main limitation is its high failure rate to achieve maturation and long-term functionality loss. Multiple strategies have attempted to identify patients at risk. Bioelectrical impedance has shown to be a valuable resource in the determination of the hydration status, and the measurement of the phase angle through this method has demonstrated to be a good indicator of the nutritional state and its related as a general marker of survival. The objective of this study is to analyze the role of plasma albumin and phase angle measured through bioelectrical impedance as tools useful for predicting failure of arteriovenous fistulas. Materials and methods: prospective observational study, including 104 patients with chronic kidney disease receiving hemodialysis who underwent a native arteriovenous fistula during a period of 24 months. Analyzing its clinical characteristics, laboratory and phase angle through electrical bioimpedance, both univariate and multivariate analysis was performed both with logistic regression, furthermore calculation of coordinates and ROC curve to establish a better cut-off point. Results: of the variables that were analyzed only the phase angle measurement showed statistical significance OR 2.61 (1.6 – 4.4) p - value 0.001 for predicting arteriovenous fistula failure. In female patients with a phase angle value of 3.25 had a 90% sensibility and 53% specificity for male patients a value of 3.58 showed a sensibility of 84% and a specificity of 52% with ROC curve of 0.78. Conclusion: phase angle through bioimpedance is a useful parameter, helpful in predicting failure of native arteriovenous fistula, it is also an important tool for identifying patients at risk, in early stages prior to the construction of a vascular access.