Choice Of Vascular Access Research Articles

Prevalence and Center Variability of Catheter-Based Hemodialysis in Vienna: Insights from the Vienna ACTS NOW Study

Objectives: The choice of vascular access continues to be a critical component in the management of hemodialysis patients. Despite the international consensus favoring arteriovenous (AV) fistulas, the use of central venous catheters (CVCs) remains prevalent, with substantial variations across countries and even among dialysis centers within the same region. This study examines the prevalence of CVC use among chronic hemodialysis (CHD) patients in Vienna, Austria, and explores inter-center differences. Methods: A cross-sectional analysis was conducted on patients receiving CVC-based CHD in Vienna as of March 2023. Patient demographics, comorbidities and their hemodialysis history were collected. Additionally, a subset of the population underwent vascular access (VA) mapping to assess eligibility for AV fistula (AVF) or AV graft (AVG) creation. Results: A total of 335 patients received CVC-based hemodialysis, equaling a CVC proportion of 42.5%. 191 (57.0%) patients on CVC-based CHD gave their consent to record their clinical data and vascular access history. Of the 191 included patients, 61 gave their consent to receive VA mapping. Of the 61 patients who received VA mapping, 60 (98.4%) were eligible for an upper extremity AVF or AVG. There was no significant difference regarding patient demographics, dialysis vintage, history of previous AVF or AVG or Charlson Comorbidity Index between the mapping and non-mapping group. The odds ratio of having a CVC in the absence of in-house vascular surgery was 3.41 (95% CI: 2.31–5.02, p-value < 0.001) compared to patients with in-house vascular surgery. Conclusions: The majority of patients that consented to ultrasound VA mapping fulfilled vascular requirements for AVF or AVG creation. Our study highlights the potential to decrease the prevalence of CVC-based CHD in Vienna that could translate to a reduction in CVC-associated complications.

#1487 Preoperative ultrasound vascular mapping as a predictor of arteriovenous fistula survival: a prospective cohort study

Abstract Background and Aims The morbidity and mortality of hemodialysis (HD) patients is directly related to the vascular access (VA) type. The arteriovenous fistula (AVF) is considered the VA of choice. When compared to the use of catheter, the use of AVF encompasses a lower infectious complications rate and a higher survival rate. The use of catheter has been independently associated with an increased risk of morbidity and mortality, especially during the first year of treatment. It is essential that HD programs maintain a high incidence and prevalence of AVF as a VA. For that reason, a multidisciplinary management is mandatory, with the collaboration of nephrologists, vascular surgeons, radiologists, and nurses. All patients who have an indication of AVF should have a prior ultrasound vascular mapping performed by the nephrologist to determine the most appropriate type of AVF. According to guidelines, there are several factors that increase the risk of AVF failure including advanced age, history of smoking, diabetes mellitus and peripheral vascular disease, among others. Therefore, the aim of this study is to determine the benefits of performing a preoperative ultrasound vascular mapping in terms of AVF survival. The secondary objective is to associate some risk factors to a higher rate of AVF failure. Method We conducted a prospective cohort study between January 2020 and December 2023. The viability of AVF was compared between AVF resulting from a preoperative ultrasound vascular mapping and those AVF without previous mapping. A multivariate analysis was performed with the entire population to determine the factors related to AVF survival. Results This study analyzed a total of 136 AVF, both native and prosthetic. Our population included 106 patients, mostly men (69.79%), with a median age of 68 years old (IR: 56-76), and history of smoking in a 39.10%, of diabetes in a 42.43%, and of peripheral vascular disease in a 17.54%. A preoperative ultrasound vascular mapping was previously performed in 107 AVF (78.7%). A total of 93 AVF were functional (68.4%). Regarding the analyzed risk factors of AVF failure (including advanced age and history of smoking, diabetes mellitus and peripheral vascular disease, and elbow/wrist AVF), we observed that advanced age and elbow AVF were related to higher survival of the AVF (p = 0.048 and p = 0.01 respectively). In the multivariate analysis we observed that advanced age and elbow AVF were independent predictors of AVF survival (p = 0.038 and p = 0.001, respectively). When comparing the cohorts, in the AVFs were the preoperative vascular ultrasound was performed, 78 AVF were functional (72.9%). In the AVFs were no mapping was performed, 15 AVF were functional (51.7%). This difference was statistically significant (p = 0.03). This implies a 21.2% increase in the probability of AVF survival when performing our AVF mapping. Conclusions The performance of a preoperative ultrasound vascular mapping by the nephrologist in our population has been associated to a significant increase in AVF survival. For that reason, we consider that it is an indispensable tool for the creation and monitoring of VA. When analyzing risk factors classically associated to AVF failure, we found that advanced age and elbow AVF were independent predictors of higher AVF survival. Other risk factors, such as history of diabetes mellitus, smoking, and peripheral arterial disease, were not significantly related to AVF failure in our population.

#3055 Replacement of tunneled cuffed hemodialysis catheters on coated guidewire: a strategic approach to treat CVC-related infections

Abstract Background and Aims Infections of tunneled hemodialysis central venous catheters (CVCs) are a serious problem, and the outcome of dialysis patients strongly depends on their clinical management. Several specialists are involved in choosing the appropriate technical and clinical strategy but often there is no consensus among them on the proper management. We believe that the role of nephrologists must be pivotal in this setting throughout the entire process, from the choice of vascular access to the management of complications. Here, we present our experience using an approach to replace CVCs that was conceived to minimize the rate of infections. Method We propose a CVC replacement technique to minimize the risk of contamination by using a guidewire coating that allow no contact between the old and new CVC. We carried out a retrospective observational study of tunneled CVCs replacement with this technique performed at the Nephrology Unit of the "A. Gemelli Polyclinic" between January 2020 and June 2023. The following parameters were analyzed: age, sex, infection-supporting pathogen, CVC age, and dialysis age. Results During the reporting period, we carried out a total of 87 CVC guidewire replacement procedures for HD tunneled catheters defined “access to be preserved” using our technique. Among the patients (median age 70,6) undergoing this procedure, n=5 (5.75%) presented with endocarditis (n=4 by Staphylococcus aureus, n=1 by Pseudomonas aeruginosa). The follow-up ranged from 6 months to 3 years. During this time only one patient, with endocarditis, had a recurrent infection caused by Pseudomonas aeruginosa after 3 months from the CVC replacement whereas 12 patients presented a de novo CVC infection caused by a different pathogen (n=4 by Staphylococcus aureus, n=1 by Pseudomonas Aeruginosa. Conclusion Overall, our data are encouraging as the lower rate of recurrent infections in our cohort suggests that our CVC replacement technique can be potentially used even in case of dangerous pathogens.

#2192 Aging dialysis population and late referral: two factors influencing the choice of vascular access

Abstract Background and Aims The decision on the type of vascular access for hemodialysis is based on several factors including the timing of renal replacement therapy initiation and certain patients’ clinical and demographic features. We hypothesized that the increasing age of patients on hemodialysis and the issue of "late referral" can be relevant in this context and favor the use of central venous catheter (CVC) over arteriovenous fistula (AVF), with a surge in catheter-related complications. Method We carried out a retrospective observational study of vascular access procedures (AVF creation and long-term CVCs placement) performed at the Nephrology Unit of the “Fondazione Policlinico Universitario Agostino Gemelli” between January 2020 and December 2023. Results A total of 415 procedures for AVF creation (median age 63.5, IQR 55.5 - 71.5 years), of which 59 (14,2%) in “late referral” patients (median age 61, IQR 47.5 - 72.5 years), were performed. During the same period, 343 CVCs were placed, of which 151 (44%) in patients with planned admission as previously evaluated by a nephrologist (median age 69, IQR 60 - 79 years). The remaining 192 CVC placements (56%) involved patients after an emergency admission (median age 69, IQR 57 - 80 years). In 56 (29%) of these patients an AVF was created concurrently or within 60 days from the emergency procedure. Such patients were significantly younger (median age 66, IQR 57 - 73 years) than those who underwent a CVC placement after a planned admission (p=0.01) or others with emergency admission (p=0.03). In a multivariate analysis (logistic regression) the use of CVC over AVF was significantly and independently correlated with both late referral and age. Conclusion These data suggest that the increasing use of CVCs in hemodialysis may be due to the age of incident patients and remark the importance of early evaluation in order to choose the most appropriate vascular access.

Patients, healthcare providers, and general population preferences for hemodialysis vascular access: a discrete choice experiment.

A patient-centered dialysis treatment option requires an understanding of patient preferences for alternative vascular accesses and nephrologists often face difficulties when recommending vascular access to end-stage kidney disease (ESKD) patients. We aimed to quantify the relative importance of various vascular access characteristics to patients, healthcare providers and general population, and how they affect acceptability for patients and healthcare providers. In a discrete choice experiment, patients with maintenance hemodialysis (MHD), healthcare providers, and individuals from the general population were invited to respond to a series of hypothetical vascular access scenarios that differed in five attributes: cumulative patency, infection rate, thrombosis rate, cost, and time to maturation. We estimated the respondents' preference heterogeneity and relative importance of the attributes with a mixed logit model (MXL) and predicted the willingness to pay (WTP) of respondents via a multinomial logit model (MNL). Healthcare providers (n = 316) and the general population (n = 268) exhibited a favorable inclination toward longer cumulative patency, lower access infection rate and lower access thrombosis rate. In contrast, the patients (n = 253) showed a preference for a 3-year cumulative patency, 8% access infection rate, 35% access thrombosis rate and 1.5 access maturity time, with only the 3-year cumulative patency reaching statistical significance. Among the three respondent groups, the general population found cumulative patency less important than healthcare providers and patients did. Patients demonstrated the highest WTP for cumulative patency, indicating a willingness to pay an extra RMB$24,720(US$3,708) for each additional year of patency time. Patients and healthcare providers had a strong preference for vascular access with superior patency. While the general population preferred vascular access with lower thrombosis rates. These results indicate that most patients prefer autogenous arteriovenous fistula (AVF) as an appropriate choice for vascular access due to its superior patency and lower complications than other vascular access types.

Transradial versus transfemoral access for diagnostic cerebral angiography: frequency of acute MRI findings in 500 consecutive patients at a single center

BackgroundThe frequency of clinically symptomatic and asymptomatic diffusion-weighted imaging (DWI) hyperintense lesions and their correlation with the transradial artery (TRA) approach is unclear.ObjectiveTo assess the frequency of abnormal diffusion restriction...

A modeling study of position and orientation of hemodialysis needles and the impact on vascular access

Patients with chronic kidney disease (CKD) need renal replacement therapy (RRT) and the favored method is hemodialysis (HD). An arteriovenous fistula is the preferred choice of vascular access, with two metal needles used to transfer the blood with waste to the dialysis machine and return the blood without waste from the dialysis machine to the patient’s body. However, wounds on the veins can cause blood clots which if left untreated could be life threatening. The hemodialysis needles can cause vascular wall abnormalities. The position and orientation of these needles might cause intimal hyperplasia (IH) and finally lead to blood clots. This study aims to analyze the hemodynamic effects on the vascular endothelium in AVF vascular access. A 15G needle was placed inside a vein at angles of 20°, 40°, and 90° with normal insertion and flipped needle in an idealized cephalic vein with the bore of the needle centrally located, conforming to standard cannulation practice. The 3D model created by SolidWorks consists of shaft, back eye, bevel, and vein only; the vein and 15G needle were assembled together. The mathematical model of blood rheology in this paper used Carreau’s law in the fluid domain. It was imported into Ansys CFX for calculation, a finite volume based software, which was implemented to solve the governing equations of the blood flow. The result showed that if the venous needle was not towards the venous return, a vortex appeared at the vein both upstream and downstream due to the venous needle, resulting in wall shear stress at the vein increasing significantly, and the flipped bevel seems to cause higher wall shear stress. For antegrade positioning of the vein vascular access return in the model when normally inserted, it was found that only 1% of the flow out of the back eye and vortex occurred downstream of the vein. Needles placed at a higher angle can increase wall shear stress and pressure on the vein. The flipped bevel is not significant in terms of either pressure or wall shear stress. However, when the needle is placed at a greater angle, wall shear stress and pressure on the vein were also increased. The flipped bevel caused higher wall shear stress and pressure when increasing the needle angle. Jetting from the venous needle causing intimal hyperplasia (IH) leads to blood clots, pain on the vein, and ultimately arm pain. Thus, the best cannulation procedure is for the venous needle to be toward the venous return, at a lower angle, and with the tip of the needle on the middle of the vein. Furthermore, the back eye should not be used for the venous needle but should be used for the arterial needle.

Diagnostic performance and inter-reviewer agreement of colour Doppler ultrasound in haemodialysis fistula and graft complications: a multicentre prospective study.

Haemodialysis provides various options for vascular access, including native arteriovenous fistulas (AVFs), arteriovenous grafts (AVGs), and central intravenous catheters. However, the use of catheters should be avoided due to their association with greater risks when opposed to AVFs or AVGs. AVFs have garnered strong endorsement as the favoured vascular access choice for extended haemodialysis. A total of 200 patients initially diagnosed with AVF/AVG dysfunction were referred to the radiology department across 3 different institutions. The inclusion criteria involved patients who encountered repeated difficulties with access cannulation during dialysis. Conversely, the exclusion criteria comprised cases that had been solely assessed using colour Doppler ultrasound (CDUS), those exclusively evaluated with digital subtraction angiography (DSA), situations where DSA was not feasible, instances requiring immediate intervention due to acute access failure, and cases in which patients refused participation. Inter-observer agreement regarding complications of AVF/AVG was very good for the identification of thrombus (κ = 1.0), seroma (κ = 0.953), aneurysm (κ = 0.851), and pseudoaneurysm (κ = 0.851). It was considered good for the detection of juxta-anastomosis stenosis (κ = 0.751) and feeding artery stenosis (κ = 0.638). However, he agreement was fair for identifying draining vein stenosis (κ = 0.380) and distal arterial steal syndrome (κ = 0.210). The overall diagnostic performance of CDUS exhibited 86% sensitivity in identifying stenosis, with a specificity of 99.1%, a positive predictive value (PPV) of 96.5%, a negative predictive value (NPV) of 97%, and an accuracy of 94.3%. CDUS is a noninvasive diagnostic approach for the prompt picking of AVF complications. It serves as a suitable first-line imaging modality for nonfunctional AVF due to its cost-effectiveness and accessibility. Additionally, we provide evidence of reproducibility, encouraging the diligent use of CDUS in AVF and AVG evaluation for early complication detection and management guidance.

Vascular Access Blood Purification Treatments in Chronic Renal Failure: Impact on Quality of Life

Objective: To observe the effects of blood purification treatment and assess the prognostic impact of different vascular pathways on patients with chronic renal failure (CRF). Methods: A retrospective analysis of clinical data was conducted on 68 CRF cases, categorizing them based on their choice of blood purification vascular access. Group A received an autologous arteriovenous fistula, Group B received an internal jugular vein tunneled polyester sleeve catheter, and Group C received a polytetrafluoroethylene graft vascular fistula. Clinically relevant observation indicators, complication rates, and quality of life scores among the three groups were compared. Results: No significant differences were found between the three groups regarding observed values of clinically relevant indicators and quality of life scores (P > 0.05). When comparing thromboembolism rates Group A had the highest rate, followed by Group C and Group B; for infection rate comparison, Group C had the highest rate, followed by Group B and Group A (P < 0.05). Conclusion: In comparison with the other two vascular access methods, although autologous arteriovenous fistula poses a higher risk of thromboembolism, it exhibits a lower infection rate. Therefore, it is recommended as the preferred vascular access form for blood purification in patients with CRF. If this approach is unavailable, careful consideration should be given. The use of an internal jugular vein with a tunneled polyester sleeve catheter is suggested to better ensure the effectiveness and safety of the patient’s treatment.

Right Access at the Right Time: Choice and Timing of Predialysis Vascular Access.

Right Access at the Right Time: Choice and Timing of Predialysis Vascular Access.

Risk factors for arteriovenous fistula dysfunction in hemodialysis patients: a retrospective study

Arteriovenous fistula (AVF) is the first choice of vascular access in hemodialysis (HD) patients. However, the correlations between patient factors and the arteriovenous fistula patency remain unclear. Therefore, our study investigates the risk factors associated with AVF dysfunction in HD patients. A total of 233 end-stage renal disease (ESDR) patients who met the study inclusion criteria in the Nephrology Department of Hunan Provincial People’s Hospital between December 2020 and June 2022 were included in this study. The baseline demographic, clinical and laboratory parameters were collected at the time of AVF creation and analyzed. Of the 233 ESRD patients, 146 (62.7%) were male and the mean age was 56.11 ± 12.14 (21–82) years. The patients were followed for a median time of 14 months. Kaplan–Meier analysis showed a 6-, 12- and 24-month post-placement survival of 87.1%, 82.8% and 80.7%, respectively. Univariate Cox regression analysis revealed weight (HR, 1.03; P = 0.03) as a predictor for the loss of vascular access functionality. In addition, multivariate Cox regression analysis further demonstrated that sex (HR, 3.41; P = 0.03), weight (HR 1.08; P < 0.01) and phosphorus level (HR: 3.03; P = 0.01) are independent risk factors for AVF dysfunction. AVF dysfunction is highly associated with several risk factors including weight, phosphorus level, and sex. Positive intervention strategies targeting these potential factors, such as weight loss or oral phosphate binders could improve the long-term success of AVF.

Complications according to intrathoracic versus extrathoracic venous access for cardiac device implantation: results from the PLACE (Planning Lead Access for Cardiac Electrostimulation) study

Abstract Background and Aims The choice of the vascular access for cardiac pacing devices (CIED) implant may impact on patients outcome. Recent studies and consensus documents encourage the use of an extra-thoracic access to prevent adverse events. In this large, multicenter, retrospective study we report the impact of leads access on post-procedural outcome. Methods Consecutive patients receiving a CIED from 2008 to 2019 in 4 high-volume Italian hospitals were enrolled. Short- and long-term complications (i.e. pneumothorax, cardiac tamponade, pocket decubitus, pocket hematoma, lead dislodgement, lead failure) were collected and their relationship with the type of vascular access (extra- vs intra-thoracic, i.e. cephalic vein/extra-thoracic axillary vein vs subclavian vein puncture) was analyzed. Primary endpoint was the occurrence of at least one complication during follow-up. Results A total of 4,443 patients were enrolled; 3,374 (75.9%) received a pacemaker (PM) and 1,069 (24.1%) an implantable cardioverter defibrillator (ICD). Mean follow-up was 1,630±1,010 days. At least one complication occurred in 7.6% of patients. At multivariate Cox regression analysis, adjusted for baseline confounders, the presence of structural heart disease (HR 1.59, 95%CI 1.21-2.10; p=0.001), anticoagulant therapy at implantation [HR 1.31, 95%CI 1.0004-1.71; p=0.05) and female gender (HR 0.78, 95%CI 0.63-0.98; p=0.03) were associated with the primary outcome measure. Extra-thoracic access did not reduce the risk of complications compared to intra-thoracic access (HR 0.97, 95%CI 0.76-1.25 p=0.81). The use of both accesses in the same patient conferred a significant increase in the risk of complications (HR vs single approach:1.95, 95%CI 1.41-2.69; p &amp;lt;0.001). Conclusions The choice of a different vascular access (intra- vs extra-thoracic) does not impact on post-procedural complications in patients receiving CIED. In particular, the intra-thoracic subclavian vein puncture by experienced operators is not related to a poorer outcome. The need for both types of access in the same patient (i.e. increased procedure complexity) increases the risk of post-procedural complications.Graphical abstract

Percutaneous Placement and Management of High-flow Catheter for Hemodialysis: The Case for DualCath, Two-tunneled, Single-lumen Silicone Catheters

Abstract Introduction: Tunneled central venous catheters (CVCs) are often regarded as the final choice for vascular access in patients needing extracorporeal renal replacement therapy due to their higher morbidity, lower performance, and increased cost. The inherent limitations of tunneled CVCs have been recognized and extensively analyzed in numerous studies. Materials and Methods: The objective is to offer a comprehensive technical note on the percutaneous placement and management of high-flow DualCath (DC) for hemodialysis, involving the simultaneous insertion of two tunneled single-lumen silicone catheters through a single skin incision and vein puncture. In addition, we aim to summarize the results derived from our extensive clinical experience. Results: This 20-year study involved the placement of 1035 DC devices. The main indications were end-stage kidney disease in 859 cases, acute kidney injury in 50 cases, and miscellaneous purposes in 30 cases. Most of the insertions were in the internal jugular vein, with varying dwell times averaging 213 ± 335 days. In total, the DC devices were used for 594 patient-years. Conclusion: DC can be placed using a minimally invasive percutaneous method in both chronic and acute settings, showcasing its exceptional versatility. The design and geometry of the two silicone cannulas are precisely tailored to meet the needs of clinicians, focusing on achieving optimal flow performance, and ensuring adequate dialysis.

Effect of far-infrared therapy device on arteriovenous fistula maturation and lifespan in hemodialysis patients: a randomized controlled clinical trial.

Arteriovenous fistula (AVF) is the first choice of vascular access for hemodialysis treatment, and its surgical maturity rate is not high, and its postoperative complications (mostly stenosis) significantly shorten its life. At present, there are few studies on treatment methods to improve the maturity and survival of AVF. In this study, the effect of far infrared therapy (FIR) on the maturity and longevity of arteriovenous fistula in hemodialysis patients was discussed, and the protective mechanism of AVF induced by FIR therapy was explored, aiming at exploring a new treatment method. The hemodialysis patients admitted to the 900th Hospital of the Chinese Joint Logistics Support Force of the People's Liberation Army from January 2021 to April 2023 were randomly divided into control group and intervention group, with 40 cases in each group. Among them, the control group was coated with mucopolysaccharide polysulfonate cream; Intervention group: The patients were treated with mucopolysaccharide polysulfonate cream and far infrared radiation at the same time. After 3 months' intervention, the arteriovenous fistula (vein diameter, mature time of arteriovenous fistula, blood flow controlled by pump during dialysis, blood flow of brachial artery during dialysis and the occurrence of complications of internal fistula (oozing, occlusion and infection) and the pain score (numerical rating scale, NRS) of the two groups were compared, and the curative effects were compared. There was no significant difference in general data between the two groups (P > 0.05), which indicated that the study was comparable. After 3 months' intervention, the vein diameter, pump-controlled blood flow and brachial artery blood flow in the intervention group were significantly higher than those in the control group (P < 0.05). And the maturity time, NRS score and complication rate of arteriovenous fistula were significantly lower than those of the control group (P < 0.05). The primary patency rate of AVF in the intervention group was higher than that in the control group, and the overall patency rate between the two groups was statistically significant (P < 0.05). As a promising new treatment method, far infrared therapy can effectively promote the maturity of AVF, increase venous diameter, pump controlled blood flow during dialysis, brachial artery blood flow during dialysis, and prolong the service life of AVF.

#5657 FRAILTY AND VASCULAR ACCESS IN HEMODIALYSIS PATIENTS

Abstract Background and Aims Frailty is a geriatric syndrome characterized by increased vulnerability to stressors. The elderly become vulnerable and susceptible to adverse outcomes for their health and to functional restrictions. Previous guidelines suggested fistula creation as first choice for vascular access. Current guidelines suggest a more tailored approach to the patient's needs. Despite the high prevalence of frailty in hemodialysis patients, there is paucity of work investigating the relationship between frailty and vascular access failure. The aim of the study was the estimation of frailty with different scores and relationship with the choice of first vascular access, the current vascular access and vascular failures. Method 67 patients in hemodialysis participated to the study (observational cross-sectional study). Frailty was assessed with 6 different scores,Clinical Frailty Scale (CFS), Frailty Phenotype (FP), Edmonton Frailty Scale (EFS), Groningen Frailty Index GFI), Short Physical Performance Battery (SPPB), Prisma-7 and ankle-brachial index (ABI) and hand grip were also estimated. The current vascular access, the first vascular access, the vascular access failures and the mean duration of the vascular accesses were also recorded. Finally, the levels of the hemoglobin, serum albumin, C reactive protein, cholesterol were measured for all patients and the hemodialysis adequacy (URR, sp Kt/V) was calculated from the levels of urea before and after the hemodialysis session. Finally, the levels of the hemoglobin, albumin, C reactive protein, cholesterol were measured for all patients and the hemodialysis adequacy was calculated from the levels of urea before and after the hemodialysis session. Results The first vascular access of hemodialysis presents statistically significant relation between frail and robust patients that start hemodialysis with central venus catheter and AVF-AVG respectively. (SPPB- tunneled CVC 85, 7%, non tunneled CVC 46,2% ρ=0,032, Prisma-7- frail tunneled CVC 100%, non tunneled CVC 76,9% ρ=0,018, Groningen FI -frail tunneled CVC 100%, non tunneled CVC 65,7% ρ=0,011, Εdmonton FS -AVF-AVG not frail 64,7%, vulnerable 20,6% ρ=0,042) (Table 1-4). ABI presented a statistically significant relationship with the current vascular access. 68,18% of the patients with normal ABI have AVF-AVG and 60,87% of patients with abnormal ABI have tunneled CVC (p=0,022). In addition, the number of vascular accesses per patient, the mean duration of the accesses and the premature failures (3 months after creation) don't present statistically significant relation with frailty. Conclusion The frailty score could be used as a tool for the choice of vascular access in hemodialysis patients. Further studies, in a larger number of patients, are required to define a reliable and easy to use frailty tool, which is best suited to dialysis access selection.

#5078 “FISTULA FIRST, CATHETER LAST” IN THE VERY ELDERLY: ONE SIZE FITS ALL?

Abstract Background and Aims The demographic characteristics of incident and prevalent hemodialysis (HD) patients have been undergoing significant changes over the last decades, in what has been called an “epidemic of aging in renal replacement therapy” [1]. The higher proportion of very elderly patients has brought significant challenges to the nephrologists, namely regarding the choice and timing of vascular access (VA) creation. Despite the arteriovenous fistula (AVF) undeniable status has the preferred VA, the applicability of the “Fistula First” initiative in very elderly patients has been questioned. Method This single-center observational retrospective cohort study took place at the Coimbra Hospital and University Centre, a Portuguese tertiary referral hospital. Patients were selected from the Nephrology department's database of HD referrals. Inclusion criteria were HD referral between January 2017 and December 2021 and age equal or over 80-years old at time of referral. We collected data regarding demographic characteristics, comorbid conditions, first VA, pre-HD nephrology care and functional status at referral, as well as the time and cause of death during the follow-up period. Functional status was assessed through the Katz index of independence in activities of daily living and the comorbid conditions were assessed through the Charlson comorbidity index. Primary outcome was mortality, and follow-up ended on the 31st of May 2022. Variables associated independently with mortality were included in Cox proportional-hazards regression models. Results Our study sample included 288 patients, predominantly male (63.9%), with a median age of 83 and a diabetes prevalence of 42.8%. The VA at first dialysis was a central venous catheter (CVC) in 77.8% and 68.1% had an unplanned HD start. Eighty-four percent had at least 3 months of pre-HD nephrology care. The mean Charlson Index at HD referral was 9.1 and 50.6% presented a Katz index under 5. The mortality incidence rate during follow-up was 32.8/100 patient-year, with 90-days, one-year, and two-year survival rates of 88.2%, 69.1% and 51.4%, respectively. The main known causes of death were infections not related with the VA (29%) and cardiovascular disease (14%). Starting HD through a CVC was associated with worse survival in univariate analysis (Log-rank 15.4, p&amp;lt;0.001). Other mortality-related variables in survival analysis were age at HD referral [hazard ratio (HR) 1.082, p&amp;lt;0.001], absence of pre-HD nephrology care (Log-rank 14.6, p&amp;lt;0.001), urgent-start HD (Log-rank 24.3, p&amp;lt;0.001), Katz index (HR 0.67, p&amp;lt;0.001) and Charlson index (HR 1.28, p&amp;lt;0.001). In a Cox Proportional Hazards model, when adjusting for the other mortality predictors, CVC use at first HD and unplanned HD start did not present a statistically significant association with mortality (HR 1.587, p = 0.074; HR 1.508, p = 0.098, respectively). Conclusion In our study sample, most patients started HD through a CVC, despite the majority having at least 3 months of pre-HD nephrology care. When adjusting for other covariates in a multivariate model, the first VA did not present a strong association with survival outcomes. The appropriate VA in the very elderly patient is an ongoing debate, and doubts remain regarding the applicability of the “Fistula First, Catheter Last” policy in octogenarian and nonagenarian patients. Our results are in line with recent reports which suggest that initial CVC use with later placement of an AVF, shortly after HD initiation, does not confer worse prognosis than initial AVF use in very elderly patients [2]. One of the limitations of our study was not having collected data regarding timings of AVF construction and use, which might have been informative regarding the impact of catheter-dependence time in survival.

Personalized choice of vascular access for isolated hepatic perfusion: analysis of complication risk stratification programs

The article presents three clinical reviews of isolated hepatic perfusion using a heart-lung machine. The probability of postoperative complications was retrospectively assessed using risk stratification programs for adverse outcomes. The conclusion is made about the effectiveness of the presented software.

The feasibility of small-caliber veins for autogenous arteriovenous fistula creation: A single-center retrospective study.

Autogenous arteriovenous fistula (AVF) is recommended as the first choice for hemodialysis vascular access. A small-caliber vein is one of the independent risk factors for AVF maturation and patency. However, the specific threshold is still unclear, making it difficult to accurately determine whether these vessels are suitable for AVF creation. This is a single-center retrospective study. Patients who underwent AVF creation in our medical center between January 2020 and September 2022 and satisfied the eligibility criteria were included in this retrospective study. Logistic regression analysis was performed to identify risk factors for functional maturation and additional intervention. The optimal cutoff value was determined based on the receiver operating curve (ROC) and the Youden index. Kaplan-Meier analysis was utilized in further patency rate comparisons. A total of 125 forearm AVFs were created in 121 patients with end-stage renal disease (ESRD). The mean age was 53.88 ± 15.10 years. Preoperative vascular Doppler ultrasound (DUS) was conducted and recorded in 106 cases (84.80%). The mean targeted artery and vein diameters were 2.17 ± 0.54 and 1.71 ± 0.75 mm, respectively. Small-caliber vein is the risk factor for functional maturation failure (OR = 0.256, 95%CI [0.06-0.75], p = 0.033) and additional intervention (OR = 0.306, 95% CI [0.09-0.78], p = 0.031). The optimal cutoff value is 1.35 mm (augmented) when specificity and sensitivity reach 80 and 63.7%, respectively. The AVFs with a vein diameter of more than 1.35 mm (augmented) showed higher patency rates (p < 0.01). After comprehensive DUS evaluation, intraoperative hydrodilation, postoperative active exercise and intensive DUS detection, and application of balloon-assisted maturation, if necessary, using a vein more than 1.35 mm (augmented), could achieve satisfactory functional maturation and postoperative patency in AVF formation.

A decade of arteriovenous fistula creations in the ⩾75 years population: Equal opportunity or sub-optimal use of resources.

The optimal vascular access in the elderly remains contentious in the context of increasingly limited resources and anticipated survival on hemodialysis. Research focus has shifted to include the impact of vascular access on quality of life. This study explored clinical outcomes in individuals aged ⩾75 years who had an arteriovenous fistula (AVF) created in a single center over a 10-year period. Demographic and clinical data concerning AVFs created January 2009-December 2019 were identified from a prospective database for retrospective analysis. Outcome measures were AVF patency and failure to mature rates plus overall patient and vascular access survival. The Vascular Access Specific Quality of life measure (VASQoL) was completed in a contemporary cohort aged ⩾75 years established on HD in October 2021. AVF outcomes were available for 272 patients (93%). The failure to mature (FTM) rate was 36% with the significant predictors of AVF FTM being the creation of a radiocephalic AVF (OR 8.13, 95% CI 8.02-8.52, p < 0.01), female gender (OR 4.84, 95% CI 4.70-5.41, p < 0.01), and a history of peripheral vascular disease (OR 5.25, 95% CI 5.22-6.00, p value = 0.02). Functional patency was associated with a median 12-month survival benefit compared to those whose fistula FTM (p < 0.01). The median patency duration for a functionally patent AVF was 3 years. Elderly patients with a fistula reported a lower quality of life in VASQoL scoring than those with central venous catheters. In this cohort, AVF creation in individuals aged ⩾75 years AVFs was associated with comparable AVF patency rates to younger patients. AVF functional patency was associated with superior patient survival compared to those with AVF FTM. A multi-disciplinary surveillance program may help reduce AVF loss. Further work on how vascular access choice impacts quality of life in elderly patients is required.

Venous thromboembolitic complications in children and adults with permanent venous access (literature review)

Introduction. Over the past decades, permanent venous access devices, in particular port systems and peripherally implanted central catheters, has been increasingly introduced in adult and pediatric oncology. As far as central catheters and permanent access devices are foreign bodies in basic veins, quite naturally that they are one more risk factor for thrombosis.Material and methods. The authors searched literature data ( in Russian and English) for the period up to May 3, 2022 using public databases (Embase, Medline/PubMed, Researchgate, medrxiv.org, RSCI/eLibrary). The following keywords were used for the search: “port-system”, “peripherally implanted central catheter”, “totally implanted vascular access device”, “venous thromboembolism”, “VTE”, “venous thromboembolic complications”, “VTEC”, “catheter dysfunction”, “device malfunction”. Available preprints, articles with “in press” or “online first” status, and clinical cases were also included in the analysis.Conclusion. This review discusses prevention, diagnostics and treatment of venous thromboembolic complications in cancer patients using similar implantable devices. In patients with catheter-associated thromboses, of practical interest are various diagnostic and curative algorithms, recommendations on the choice of vascular access, medicamentous therapy as well as variants of surgical intervention.