Vascular Access Research Articles

Pulsed Field Ablation Using Focal Contact Force-Sensing Catheters for Treatment of Atrial Fibrillation: 1-Year Outcomes of the ECLIPSE AF Study.

Pulsed field ablation (PFA) is a promising treatment for atrial fibrillation. We report 1-year freedom from atrial arrhythmia outcomes using monopolar PFA delivered through 3 commercial, contact force-sensing focal catheters. ECLIPSE AF (NCT04523545) was a prospective, single-arm, multicenter study evaluating acute and chronic safety and performance using the CENTAURI system to deliver focal PFA with TactiCath SE, StablePoint, and ThermoCool ST. Patients with paroxysmal or persistent atrial fibrillation underwent pulmonary vein (PV) isolation under deep sedation or general anesthesia and returned for remapping at 90 days to evaluate chronic durability. Freedom from atrial arrhythmia was evaluated continuously through 12 months using standard rhythm monitoring for symptomatic episodes and 24-hour Holter at 6 and 12 months. Eighty-two patients (74% male, 51.2% paroxysmal, and 58.5% deep sedation) were treated. PV isolation was achieved in 100% of targeted veins (322/322) with first-pass isolation in 92.2% (297/322). There were 4 primary safety events in 4 patients (4.9%, 4/82); 1 nonembolic stroke due to exacerbated cardiac tamponade secondary to catheter perforation and 3 hemorrhagic vascular access complications. There were no incidences of adverse event fistula, diaphragmatic paralysis, MI, pericarditis, thromboembolism, PV stenosis, transient ischemic attack, or death. Eighty patients (98%) underwent remapping. Optimized PFA cohorts 3, 4, and 5 showed per-patient isolation rates of 60%, 73%, and 81% and per-PV isolation rates of 84%, 90%, and 92%, respectively. One-year freedom from atrial arrhythmia was 80.2% (95% CI, 69.7%-87.4%) for the entire patient sample, including 41 patients who underwent repeat focal PFA with the CENTAURI system at remapping. This study demonstrated that optimization of focal PFA with 3 contact force-sensing, solid-tip ablation catheters resulted in the progressive improvement of PV isolation durability at 3-month remapping and high freedom from atrial arrhythmia survival rates, providing a promising focal PFA treatment option integrated with current ablation workflows.

Macrowire for intracranial thrombectomy: An early experience of a new device and technique for anterior circulation large vessel occlusion stroke.

Mechanical thrombectomy (MT) has become the standard of care for treatment of acute ischemic stroke secondary to large vessel occlusion up to 24 h from the last known normal time. With ADAPT and SOLUMBRA techniques, classically, a large bore aspiration catheter is delivered over a microcatheter and microwire crossing the clot to perform thrombectomy. Recently, a novel macrowire (Colossus 035 in.) has been introduced as a potential alternative to the use of microwire-microcatheter to allow the delivery of the aspiration catheter (ID = 0.070 in. up to 0.088 in.) over a macrowire alone. To test the feasibility of delivering an aspiration catheter to clot interface over a macrowire alone. A retrospective evaluation of prospectively maintained Macrowire for Intracranial Thrombectomy (MINT) Registry where this novel technique was utilized for thrombectomy. Consecutive patients undergoing MT using the MINT technique were included. We collected baseline demographics, imaging and clinical characteristics, rate of procedural success, conversion to traditional MT, and complications. Fifty consecutive patients were recruited during the initial 4 months of the larger study duration. The aspiration catheter was able to be advanced to the clot interface successfully in 46/50 (92%) using the MINT technique. Median time from vascular access to the first pass was 11.30 min (IQR = 7.45-14.30 min) and successful thrombectomy was 14 min (IQR = 10-22.15). The modified first-pass effect with this procedure was 71%. One vasospasm was reported as a procedural complication. MINT is safe and feasible for large vessel occlusion recanalization based on our initial clinical experience in this multicenter study.

Factors affecting the unused short peripheral catheters: A neverending debate? A cross-sectional study in hospitalized patients.

Concern about unused vascular access devices has increased, but data on idle short peripherally intravascular catheters in medical-surgical units is still scarce. We aimed to assess the prevalence of unused short peripheral catheters in hospitalized patients and identify risk factors and reasons that lead nurses to maintain them in situ. A cross-sectional observational study was performed in September 2022. Clinical observation (24h) and medical records review were assessed to collect patient demographics and catheter-related information. Nurses were asked the main reason for continuing the use of the unused catheter. The primary outcome was the prevalence of unused short peripheral catheters, which were no longer used for intravenous fluids or medications in the previous 24 h. Multivariate logistic regression has been performed to evaluate risk factors for unused catheters. The STROBE checklist was used to report our study. Seven hundred and sixty-four patients were included; out of the 621 patients with at least one short peripheral catheter, one-third had at least one unused catheter. The risk of having an unused peripherally intravascular catheter was almost double when the catheter was positioned in the emergency department. Catheters of smaller calibers and in situ for fewer days were less likely to be unused. The main reasons for keeping a peripherally intravascular catheter unused in situ were clinical conditions. Unused short peripheral catheters are still quite frequent. While specific clinical needs justified some unused short peripheral catheters, a proportion remained unexplained and potentially avoidable. Nurses and policymakers can use the findings to inform decision-making and protocols to manage peripherally inserted catheters to reduce unused short peripheral catheters and, consequently, complications and costs and improve patient safety and quality of care.

Same-Day Discharge After Uncomplicated Transcatheter Tricuspid Valve-In-Valve Implantation.

Tricuspid valve-in-valve (TVIV) implantation has traditionally included post-procedure overnight in-hospital observation with next-day discharge. Recently, our practice has shifted toward same-day discharge for most patients after vascular access site hemostasis and adequate recovery from anesthesia. However, data on the safety of this approach remains scarce. Our study aims to describe our practice change and to identify factors that may lead to overnight observation post-TVIV. We retrospectively reviewed medical records of patients who underwent uncomplicated TVIV implantation as an outpatient procedure at Mayo Clinic between 2011 and 2023. Of the 83 patients who underwent TVIV from 2011 to 2023, 65 (78%) were included in the study. The first 39 patients in our institutional series were observed overnight as standard practice. 18 (69%) of the most recent 26 patients in our series were discharged the same day; three patients who remained in the hospital overnight were because of provider preference and/or patient preference without any specific medical concern. Of all 47 patients who were observed overnight, one patient was treated for fluid overload, one patient had non-sustained ventricular tachycardia on telemetry that resulted in adjustment of antiarrhythmic therapy, two patients had continued bleeding from the access sites and was observed for another day. Among the two of them, one also developed atrial tachyarrhythmias requiring initiation of additional antiarrhythmic therapy. Out of 18 patients discharged the same day, one patient had an ED presentation within 24 h due to access site bleeding which was resolved promptly. There was no mortality or procedural-related readmission. Same-day discharge may be considered for adult patients who have undergone uncomplicated TVIV with adequate hemostasis and recovery after anesthesia.

A prospective, observational study of a pediatric affect and cooperation scale (HRAD±) for vascular access procedures.

Anxiety is common in pediatric patients, especially during vascular access procedures. Most well-studied affect and anxiety scales, including the Observation Scale of Behavioral Distress-Revised (OSBD-r), the modified Yale Preoperative Anxiety Scale (mYPAS), and the modified Induction Compliance Checklist (mICC), are too cumbersome for clinical use outside of research settings. HRAD± (Happy, Relaxed, Anxious, Distressed with yes/no to cooperation) is a clinically-efficient observational scale that evaluates pediatric procedural affect and cooperation. This study examined the clinical utility of HRAD± during vascular access procedures in children. The aims were to investigate the correlation of HRAD± to highly reliable, research-based affect and cooperation scales and to assess inter-rater reliability (IRR) between observers in this setting. This was a prospective, observational study conducted at Lucile Packard Children's Hospital Stanford. Inpatient participants were 1 month to 25 years old and undergoing a peripheral intravenous insertion or phlebotomy. Two trained research assistants (RAs) scored each patient independently during the vascular access procedure using HRAD±, OSBD-r, mYPAS, and mICC. Correlation analyses computed the associations between HRAD± and reference scales. IRR between RAs and vascular access providers was calculated using Fleiss' Kappa. A total of 234 patients were included. HRAD± scores strongly correlated with OSBD-r and mYPAS (p < 0.0001, p < 0.0001, respectively). The cooperation assessment of HRAD± demonstrated strong correlation to mICC (p < 0.0001). IRR of HRAD± between research assistants and vascular access providers showed moderate agreement (p < 0.0001). HRAD± demonstrated strong correlation to the reference affect and cooperation scales. This study supports the utility of HRAD± for rapid assessment of pediatric procedural anxiety and cooperation during vascular access procedures. HRAD± can serve as a practical tool for facilitating clinical decisions, and its wider incorporation into healthcare settings would importantly guide targeted interventions to reduce patient anxiety.

Ulnar-Basilic Arteriovenous Fistula for Hemodialysis: A 15-Year Overview.

Distal forearm arteriovenous fistulas (AVFs) for hemodialysis (HD) include radiocephalic fistulas (RCFs) and ulnar-basilic fistulas (UBFs). However, due to the unique anatomical peculiarities of the latter approach, UBFs are only established in a limited subset of patients undergoing vascular access procedures. This study aimed to present a retrospective case series detailing the creation of UBFs, emphasizing both the technical challenges and clinical outcomes associated with this approach. We conducted a retrospective review of UBFs created between 2008 and 2023. Data collected included patient demographics, comorbidities, patency, functionality, and outcomes. Adequate blood flow and personalized Kt/Vurea levels were prerequisites for defining UBF functionality for HD. Among 253 patients receiving HD, 82.2% had an AVF, with only 3.3% (n = 5) of the 150 distal AVFs functional for HD being UBFs. In this series, a total of 11 UBF fistulas were created, with nine patients experiencing an immediate thrill. Among those with UBF failure, three patients were aged > 85 years, and three had concurrent diabetes mellitus, peripheral vascular disease, and ischemic heart disease. The survival rate in the UBF group correlated with the duration of dialysis in the three patients for whom the UBF was the sole AVF, with one patient achieving a remarkably prolonged period of > 10 years. No incidences of ischemia, hand edema, or ulnar nerve lesions were noted. While the difficulties experienced in achieving functional UBFs for HD are highlighted in this long-term perspective, its safety and durability make it a viable option in managing an increasingly comorbid patient population.

Physicians’ clinical experience and perspectives following a pilot, blended learning, point of care ultrasound course in Ghana- a mixed methods analysis

BackgroundPoint of Care ultrasound (POCUS) is rapidly gaining popularity in resource constrained settings. Optimising training is important to ensure safe and effective implementation. To expand POCUS expertise in Ghana, we co-developed and piloted a context specific, multi-disciplinary, blended learning programme, targeted at physicians of any grade or speciality providing acute care in the public health sector. In this retrospective mixed method study, we capture the “real world” experience of participants, using POCUS in their daily practice, as well as the barriers and enablers they perceived to implementation.ResultsEight emergency and internal medicine specialists and residents participated, working across three teaching hospitals, treating both general and specialist patients. They implemented each POCUS application taught, with cardiac indications, inferior vena cava (IVC) assessment, deep venous thrombosis (DVT) diagnosis, lung/pleural assessment and peripheral vascular access being most frequent at 3–6 times/week. An estimated 40% of patients could not have afforded any other diagnostic tests. They considered the pilot curriculum adequate for general practice and the majority of applications of low difficulty (71%). For cases sent for second opinion, they are self-reported that their findings were confirmed in 60–78% of cases. Perceptions about the relative advantage of POCUS over the usual approaches to diagnosing patients enabled implementation. Generally, they believed that POCUS improved their clinical decision making and that more certified training courses need to be run at lower cost to make them more accessible. All participants valued ongoing connections after training to ask for help and consolidate their skills. Continued evaluation and reflection on their POCUS practice to improve quality was unanimously reported as important, yet none had a formal system for this. The strongest barrier was access to equipment and maintenance. A lack of training opportunities and local mentors, and negative beliefs from other departments and hospital administration were further barriers.ConclusionOur new blended learning curriculum met the needs of physicians caring for patients with general and specialist presentations, with strong reported positive experience of improved bedside diagnostic capabilities, especially for the large proportion of patients unable to afford or access alternative diagnostic tests. Their experience drives the need for further training and for solutions to current barriers of equipment availability, training costs and lack of quality assurance mechanisms.

A uremic patient with autogenous arteriovenous fistula developed tension blisters after initial puncture

Tension blisters usually occur in the presence of local swelling or excessive pressure. Tension blisters after puncture injury are relatively rare in uremic patients who use autogenous arteriovenous fistula (AVF) for hemodialysis treatment. In this report, the patient we reported developed tension blisters after the initial puncture injury. Arterial CTA revealed obvious stenosis of the right subclavian vein and the patient was diagnosed with venothoracic outlet syndrome (VTOS). In this case, the occurrence and development of tension blisters after dialysis puncture injury were observed. Furthermore, the etiology, treatment measures, and methods for preventing the occurrence of tension blisters are illuminated to further improve the quality of vascular access.

Clinical Practice Guidelines for Adult Vascular Access: The Protocol for the Association for Vascular Access Clinical Practice Guidelines Systematic Review

Abstract The Institute of Medicine (IOM) defines clinical practice guidelines (CPGs) as “statements that include recommendations intended to optimize patient care that are informed by a systematic review of evidence and an assessment of the benefits and harms of alternative care options. Creating clinical practice guidelines involves a systematic process that ensures the development of evidence-based and reliable recommendations for health care professionals. The Association for Vascular Access’ CPGs are being developed by a diverse multidisciplinary team to provide evidence-based recommendations and guidance for health care professionals involved directly and indirectly in vascular access administration, leadership, device insertion, and care. This protocol outlines the process implemented to develop CPGs to ensure the reader trusts in the accuracy. The AVA CPG protocol presents a comprehensive and evidence-based approach to vascular access care. By providing standardized recommendations, it aims to improve patient outcomes, reduce complications, and enhance the delivery of high-quality care. The protocol serves as a valuable resource for health care professionals involved in vascular access management, facilitating best practices and promoting standardized approaches to enhance patient safety and quality of care.

How to Pick a Lock: Locking Solutions in Vascular Access: Editor’s Message

How to Pick a Lock: Locking Solutions in Vascular Access: Editor’s Message

Complex central vascular access in a patient with congenitally corrected transposition of the great arteries with bi-caval and bilateral iliac vein thrombosis: a case report

Complex central vascular access in a patient with congenitally corrected transposition of the great arteries with bi-caval and bilateral iliac vein thrombosis: a case report

Point-of-care ultrasonography in pediatric intensive care units

Bedside ultrasonography, or point-of-care ultrasonography (POCUS), is increasingly becoming widely adopted in pediatric intensive care units (ICU) for procedural interventions and diagnostics. Although vascular access remains one of the primary applications of POCUS in the pediatric ICU, its use for assessing fluid status and responsiveness is growing. POCUS helps identify reversible causes of cardiac arrest, such as pericardial effusion and pneumothorax, although its impact on outcomes is still under investigation. Here, we will review the applications of POCUS in the pediatric ICU, including the general pediatric and cardiac ICUs. We will discuss the up-to-date evidence guiding its use and adoption for critically ill children.

Liposuction for Superficialization of Deep Hemodialysis Vascular Access: A Novel Application.

More than 65% of patients with end-stage renal disease (ESRD) use arteriovenous fistulas (AVFs) for hemodialysis. The increasing incidence of comorbid ESRD and obesity (body mass index, >35 kg/m2) precludes patients from kidney transplantation, resulting in a need for long-term, durable AVF access. Compared with traditional superficialization techniques for overlying adiposity, liposuction is minimally invasive and well-tolerated, allowing for earlier fistula use with lower complications. We present the detailed surgical technique for superficialization of AVFs using liposuction. Fourteen patients with well-matured but difficult-access fistulas due to adiposity were selected. Preoperative ultrasound mapped depth of fistulas. Tumescent liposuction was completed in a cross-hatched manner. Intraoperative ultrasound confirmed cannula positioning and measured fistula depth. A palpable thrill remained throughout superficialization. Cannulation began 4 weeks postoperatively. Mean access depth preoperatively was 10.8 mm (8-15 mm), immediately postoperative was 7 mm (6-9 mm), and at 4 weeks was 5.3 mm (4-8 mm). The average usable access length was 12.7 cm (10-15 cm) after surgery. Thirteen fistulas were successfully accessed after liposuction superficialization. All patients were discharged home the same day. There were no postoperative infections or hemorrhage. Early experience with liposuction for superficialization of deep hemodialysis access is promising. This innovative solution has the possibility to improve outcomes and quality of life for patients living with ESRD and obesity. Our experience shows that this is a safe and effective technique to increase patient eligibility, enable successful and early cannulation, and decrease recovery time.

Observational Experiment of Catheter Reflux During Huber Needle Withdrawal In Two Countries

Abstract Introduction: Over the past 30 years, the use of implanted vascular access devices (IVAD) for long-term administration of vesicants, parenteral nutrition, blood products, and antimicrobials has grown exponentially. IVADs are a vital part of patient care, improve quality of life, and help with body image. Despite the positive aspects of IVAD, complications can still occur, one of which is device occlusion as a result of blood reflux. Methods: This observational experiment was conducted in the United Kingdom and the United States. The investigators in each country tested six Huber needles and measured the fluid reflux in the IVAD catheter upon removal of each Huber. This simple experiment was done using an in vitro port with a six French catheter secured to a ruler to measure fluid reflux into the port catheter upon removal of the six available Huber needles. Six commercially available Huber needles were each tested unclamped and clamped three times upon removal; the average was then calculated. Results: The findings demonstrated fluid reflux volumes with the six Hubers ranging from 0.0 to 0.6 cm unclamped and 0.0 to 0.7 cm of fluid reflux with the Hubers clamped. Only one Huber had no fluid reflux during needle withdrawal from the IVAD without clamping the tubing and with the tubing clamped. Five of the Hubers had fluid reflux during removal when unclamped and clamped. Conclusions: This experiment confirmed and revealed the differences in fluid reflux when removing a Huber needle from a port unclamped and clamped. Highlighted was the need for further research on fluid reflux and the potential impact it has on port occlusions. This experiment demonstrated that positive pressure needle withdrawal reduced reflux, compared to positive pressure flushing. Understanding the reflux associated with each Huber needle when de-accessing a port can potentially reduce port occlusions subsequently, improving patient outcomes.

PREDICTING HIGH FLOW ARTERIOVENOUS FISTULAS AND CARDIAC OUTCOMES IN HEMODIALYSIS PATIENTS.

Heart failure is common in patients receiving hemodialysis. A high flow arteriovenous fistula (AVF) may represent a modifiable risk factor for heart failure and death. Currently, no tools exist to assess the risk of developing a high flow AVF (>2000 mL/min). The aim of this study was to use machine learning to develop a predictive model identifying patients at risk of developing a high flow AVF and to examine the relationship between blood flow, heart failure, and death. Between 2011 and 2020, serial AVF blood flows were measured in 366 prevalent hemodialysis patients at two tertiary hospitals in Australia. Four prediction models (deep neural network, and 3 separate tree-based algorithms) employing age, first AVF flow, diabetes, and dyslipidemia were compared to predict high flow AVF development. Logistic regression was used to assess the relationship between AVF blood flow, heart failure, and death. High flow AVFs were present in 31.4% of patients. The bootstrap forest predictive model performed best in identifying those at risk of a high flow AVF (AUC 0.94, sensitivity 86%, specificity 83%). Heart failure prior to vascular access creation was identified in 10.2% of patients with an additional 24.9% of patients developing heart failure after AVF creation. Long-term mortality after access formation was 27%, with an average time to death after AVF creation of 307.5 ± 185.6 weeks. No univariable relationship using logistic regression was noted between AVF flow and incident heart failure after AVF creation or death. Age, flow at first measurement >1000 mL/min, time to highest AVF flow, and heart failure predicted death after AVF creation using a general linear model. Predictive modelling techniques can identify patients at risk of developing high flow AVF. No association was seen between AVF blood flow rate and incident heart failure after AVF creation. In those patients who died, time to highest AVF flow was the most important predictor of death after AVF creation.

The Survivability of Bacterial Contaminants on a Retracted Stainless-Steel Needle Within a Novel Vascular Access Device

Highlights Abstract Background: Over-the-needle (OTN) peripheral intravenous catheters (PIVCs) are crucial in modern medicine. However, the OTN design allows for direct catheter-to-skin contact during insertion, leaving the sterile catheter at risk for bacterial contamination from the skin. A novel through-the-needle (TTN) PIVC design aims to minimize this risk by shielding the sterile catheter during insertion with the introducer needle. This needle then permanently retracts into the device housing and remains with the patient. In this study, we evaluate the survivability of bacterial contaminants on the retracted needle to address concerns about potential infection risks associated with this design. Methods: Fifteen TTN PIVC devices were inoculated with Staphylococcus aureus (101 to 102 CFU) on the outer surface of the needle. After needle retraction, devices were stored for 0, 24, 72, and 120 hours. At each time point, devices were processed, and bacterial survival was quantified using standard microbiological techniques. Results: The initial bacterial load (105.1 ± 51.4 CFU per device) decreased significantly over time. By 72 hours, bacterial count had reduced to 1.4 ± 2.4 CFU per device, representing a 98.7% reduction (P &amp;lt; 0.05). No significant change was observed between 72 and 120 hours. The most substantial decline occurred within the first 72 hours, with the difference between 0 hours and both 72 and 120 hours being statistically significant (P = 0.016 for both). Conclusions: The significant reduction in bacterial population on the retracted needle over time suggests a low risk of bacterial propagation within the TTN PIVC device. These findings indicate that the TTN design effectively addresses catheter contamination concerns during insertion without introducing additional infection risks due to needle retention.

Perceptions of healthcare providers on benefits, risks and barriers regarding intradialytic exercise among haemodialysis patients

ABSTRACTPurposeClinical guidelines call for the inclusion of exercise interventions in every patient’s dialysis session, but these recommendations are rarely adopted. Healthcare providers play a key role in this. Therefore, the aim of this study was to explore how healthcare providers perceive the benefits, risks and barriers of intradialytic exercise (IDE).MethodsWe conducted 21 individual, semi-structured interviews with 11 nurses, 5 nephrologists, 3 training assistants and 2 managers from two dialysis centres in Slovakia. Verbatim transcripts of digitally recorded interviews were thematically analysed using MAXQDA®.ResultsParticipants reported the benefits of IDE as improvements in patients’ physical and psychosocial functioning, independence and self-efficacy, clinical profile and quality of therapy. As risks of IDE, they most frequently reported exercise-related damage to vascular access, insufficient individualization of training and musculoskeletal injuries. The presence of psychological problems among patients was reported as a major barrier for initiating and maintaining patients’ exercise. Other reported barriers included limitations in financial and personnel resources of haemodialysis care.ConclusionsSafe and sustainable implementation of IDE, which might improve a patient’s well-being, need to be prescribed in alignment with the patient’s clinical profile, be delivered individually according to the patient’s characteristics and requires adjustments in the available resources.

Risk assessment tool for compatibility of concurrent administration of intravenous medications with parenteral nutrition admixture.

Compatibility of parenteral nutrition admixture (PNA) and intravenous medications (IVMs) is a major consideration for clinicians and clinical pharmacists, especially when concurrent administration of PNA with IVMs is unavoidable. This is relatively common in children and neonates, where limited vascular access can be challenging. The purpose of this paper is to create a risk assessment tool that will assist clinical judgment in evaluating the potential incompatibility risk between PNA media and the IVMs when they are administered together through the same intravenous line. The tool will help to provide a more structured approach for healthcare professionals involved in the provision and administration of PNA to assess the risk of incompatibility of IVMs with PNA media.

IMPORTÂNCIA DO AUTOCUIDADO COM A FÍSTULA ARTERIOVENOSA EM PACIENTES DE HEMODIÁLISE: UMA REVISÃO INTEGRATIVA

Chronic Kidney Disease is characterized by a slow and progressive decline in kidney function, with hemodialysis being an essential treatment in advanced stages. For the success and effectiveness of hemodialysis treatment, an effective vascular access is necessary. Considered the gold standard for providing efficient treatment with greater comfort and longevity, the arteriovenous fistula is preferable, but its maintenance requires proper self-care practices. Objective: To understand how the lack of self-care can impact complications associated with the arteriovenous fistula in hemodialysis patients. Method: This is an integrative review, in which articles were searched through the Virtual Health Library (VHL) databases (Scielo, Lilacs, and Medline) and PubMed, using combinations of the following indexed Health Sciences descriptors: ("self care" OR care) AND "Renal Dialysis" AND "Arteriovenous Fistula" AND Nursing. Results: The results highlight the need for educational interventions and practices aimed at specific self-care for the preservation of the arteriovenous fistula. Conclusions: A deficit in self-care practices related to the arteriovenous fistula is recognized. The relevance of the nursing professional in nephrology is emphasized, highlighting their central role in promoting self-care for the arteriovenous fistula

Fluid–structure interaction in a follow-up study of arterio-venous fistula maturation

Arteriovenous fistula (AVF) is the preferred vascular access for hemodialysed patients. AVF is created surgically using the patient’s artery and vein. Once the connection (anastomosis) is made, the maturation process begins. Studies have shown that most AVFs do not survive beyond one year. This study presents fluid–structure interaction (FSI) modelling of non-Newtonian blood flow through an end-to-side radio-cephalic AVF, investigated weekly during a 15-week follow-up period and 1.5 years postoperatively using ultrasound methods. The aim was to collect qualitative and quantitative data regarding changes in hemodynamics and alterations in the walls of AVF vasculature. Different material properties were assigned to the artery, suture zone (anastomosis), and vein, while the stiffening of the venous arm over time was also modelled. The proposed FSI methodology can be implemented in future follow-up studies involving groups of patients. The main findings revealed: a) counter-rotating vortices in the anastomosis cross-section affecting local pressure conditions; b) different temporal progression of vorticity, shear strain rate, and turbulent kinetic energy and similarity of the temporal progression of WSS obtained under the assumptions of the rigid-walled and FSI; c) a negligible low-WSS zone in the presented thrombosis-free AVF; d) migration of the zone of maximal temporal wall deformation over time.