Placement of tunneled hemodialysis catheters - interventional standard.

While the native arterio-venous fistula (AVF) remains the first choice in vascular access for most hemodialysis patients, tunneled hemodialysis catheters (tHDC) continue to be an option in selected patients. Since timely access to vascular surgery-due to delayed referral or resource limitations-is not always possible, nephrologists have to become more actively involved in planning, creation and monitoring of vascular access. Moreover, this approach could also strengthen patient-centered care in nephrology. This manuscript reviews the current standard in tHDC creation, patient selection and strategies to mitigate the risk of infectious complications and catheter thrombosis. Presentation of novel developments in catheter placement with ultrasound-guided or ECG-guided positioning, their benefits and possible disadvantages emphasizes the complexity of vascular access planning. We offer an approach for choice of insertion method, depending on selected side and existing resources and set focus on the necessity and required resources of 'interventional nephrology' training programs.

Effect of insertion site on tunnelled haemodialysis catheter outcomes: an observational study of 967 catheters.

BACKGROUND: The right internal jugular vein is the preferred approach to tunnelled haemodialysis catheter placement. However, the effect of the insertion site on long-term catheter outcomes remains uncertain. AIMS: We aimed to analyse a large cohort of tunnelled haemodialysis catheter placements to compare short-term and long-term results according to central venous catheter location. METHODS: A retrospective cohort study was performed on consecutive tunnelled catheter insertions at two centres over 7 years. The primary outcome was catheter survival, compared according to the central vein site. We used the Kaplan-Meier curve method and Cox proportional hazards modelling to determine the effect of the catheterisation route on primary patency, adjusted for clinical risk factors for catheter failure. RESULTS: There were 967 tunnelled dialysis catheter placements in 620 patients. The median survival for right internal jugular vein catheters was 569 days. There were no differences in rates of catheter failure between right internal jugular, left internal jugular (adjusted hazard ratio [HR], 0.80; 95% confidence interval [CI], 0.52-1.21), external jugular (HR, 0.79; CI, 0.33-3.13), subclavian (HR, 0.67; CI, 0.58-2.44) and femoral vein (HR, 1.20; CI, 0.36-1.33) catheters following multivariable analysis. There were no major differences in functionality or complications between the groups. CONCLUSIONS: This study identified no statistically significant relationship between tunnelled haemodialysis catheter insertion site and catheter survival. The contemporary approach to dialysis vascular access should be tailored to specific patient circumstances.

Comparing surgeon- and nephrologist-inserted Tenckhoff catheters: experience from a metropolitan centre in Sydney.

BACKGROUND: Peritoneal dialysis (PD) is an effective home-based form of dialysis. Although several factors limit its use, the timely and successful insertion of a PD catheter is essential for increased uptake. AIMS: This retrospective observational study was performed at a tertiary teaching hospital in Sydney with the aim of comparing outcomes of PD catheter insertion using a percutaneous, modified Seldinger technique utilised by a trained nephrologist to the traditional surgical insertion using a mini-laparotomy. RESULTS: Over an 8-year period, 194 PD catheters were inserted. Aside from lower body mass indexes in the nephrologist-led interventions (P = 0.02), patient demographics were well matched. Time-to-insertion was significantly shorter with the percutaneous technique (P < 0.001). Univariant logistic regression noted no difference in the complication rate between the nephrologist-inserted and surgically inserted groups (likelihood ratio, 1.59; P = 0.08). There were differences in the type of adverse outcomes with each technique. Surgical procedures were more likely to have exit site leaks (P = 0.009) and peritonitis (P = 0.004), whereas procedure abandonment (P = 0.009) was more common in nephrologist-led procedures. CONCLUSIONS: The current study highlights that with careful patient selection, trained nephrologists in metropolitan areas can successfully insert PD catheters. Our experience noted fewer delays to catheter insertion, with similar total complication rates.

Practice of dialysis access interventional nephrology procedures in the Asia-Pacific region: Getting lay of the land.

AIM: This cross-sectional survey aimed to determine the prevalence of Interventional Nephrology (IN) practice amongst nephrologists in the Asia-Pacific Region (APR), specifically related to dialysis access (DA). METHODS: The Association of VA and intervenTionAl Renal physicians (AVATAR) Foundation from India conducted a multinational online survey amongst nephrologists from the Asia-Pacific to determine the practice of IN in the planning, creation, and management of dialysis access. The treatment modalities, manpower and equipment availability, monthly cost of treatment, specifics of dialysis access interventions, and challenges in the training and practice of IN by nephrologists were included in the survey. RESULTS: Twenty-one countries from the APR participated in the survey. Nephrologists from 18 (85.7%) countries reported performing at least one of the basic dialysis access-related IN procedures, primarily the placement of non-tunnelled central catheters (n-TCC; 71.5%). Only 10 countries (47.6%) reported having an average of <4% of nephrologists performing any of the advanced IN access procedures, the most common being the placement of a peritoneal dialysis (PD) catheter (20%). Lack of formal training (57.14%), time (42.8%), incentive (38%), institutional support (38%), medico-legal protection (28.6%), and prohibitive cost (23.8%) were the main challenges to practice IN. The primary obstacles to implementing the IN training were a lack of funding and skilled personnel. CONCLUSION: The practice of dialysis access-related IN in APR is inadequate, mostly due to a lack of training, backup support, and economic constraints, whereas training in access-related IN is constrained by a lack of a skilled workforce and finances.

Arteriovenous fistulae after renal biopsy: diagnosis and outcomes using Doppler ultrasound assessment.

BACKGROUND: Percutaneous renal biopsy (PRB) is an important technique providing relevant information to guide diagnosis and treatment in renal disease. As an invasive procedure it has complications. Most studies up to date have analysed complications related to bleeding. We report the largest single-center experience on routine Doppler ultrasound (US) assessment post PRB, showing incidence and natural history of arteriovenous fistulae (AVF) post PRB. METHODS: We retrospectively analysed 327 consecutive adult PRB performed at Ramon Cajal University Hospital between January 2011 and December 2014. All biopsies were done under real-time US guidance by a trained nephrologist. Routine Doppler mapping and kidney US was done within 24 h post biopsy regardless of symptoms. Comorbidities, full blood count, clotting, bleeding time and blood pressure were recorded at the time of biopsy. Post biopsy protocol included vitals and urine void checked visually for haematuria. Logistic regression was used to investigate links between AVF, needle size, correcting for potential confounding variables. RESULTS: 46,5% were kidney transplants and 53,5% were native biopsies. Diagnostic material was obtained in 90,5% (142 grafts and 154 native). Forty-seven AVF's (14.37%) were identified with routine kidney Doppler mapping, 95% asymptomatic (n = 45), 28 in grafts (18.4%) and 17 natives (9.7%) (p-value 0.7). Both groups were comparable in terms of comorbidities, passes, cylinders or biopsy yield (p-value NS). 80% were <1 cm in size and 46.6% closed spontaneously in less than 30 days (range 3-151). Larger AVF's (1-2 cm) took a mean of 52 days to closure (range 13-151). Needle size was not statistically significant factor for AVF (p-value 0.71). CONCLUSIONS: Contrary to historical data published, AVF's are a common complication post PRB that can be easily missed. Routine US Doppler mapping performed by trained staff is a cost-effective, non-invasive tool to diagnose and follow up AVF's, helping to assess management.

Is nephrology specialty at risk?

Interest in nephrology as a career choice has been steadily waning among internal medicine residents. This decline is reflected in a significant increment in unfilled fellowship training spots for several years. Interventional nephrology can help to reinvigorate an interest in nephrology as a whole.

Hand Ischemia in a Patient With an Arteriovenous Fistula.

An ischemic digit causes significant morbidity due to its associated discomfort and potential for tissue necrosis. Historically, when this phenomenon was peripheral to an ipsilateral arteriovenous access in a hemodialysis patient, it was called "steal syndrome" and was usually treated with access ligation, resulting in loss of the access. We present a dialysis patient with hand pain due to ischemia that was referred for access ligation. Instead, a minimally invasive banding procedure was performed that resulted in access salvage and resolution of symptoms. We present images and a discussion of the diagnosis and treatment of distal hypoperfusion ischemia syndrome in this Imaging Teaching Case.

Low Posterior Internal Jugular Vein Approach for Tunnelled Haemodialysis Catheter Insertion: A Report on Outcomes at a Single Centre.

AIM: The impact of technical differences in cannulation technique for tunnelled haemodialysis catheter insertion is undetermined. We aimed to assess clinical outcomes of the low posterior approach for internal jugular vein tunnelled catheter placement. METHODS: A retrospective audit was undertaken on consecutive tunnelled catheter procedures performed at a single centre between January 2016 and June 2022. Only catheters specifically placed with a low posterior internal jugular approach were included. The study's primary outcome was 12-month catheter survival, evaluated using the Kaplan-Meier survival curve and log-rank test. Secondary outcomes included catheter performance and procedure-related complications. RESULTS: During the study period, 391 tunnelled internal jugular haemodialysis catheters were inserted in 272 patients using the low posterior technique. The 12-month primary patency rate was 68%. Catheter insertion was successful in 96% of cases. Peri-procedural complications occurred in 4% of cases, most frequently bleeding. The most common reasons for catheter loss were dysfunction (10%) and bacteraemia (6%). The best predictors of catheter failure were advanced age (HR 1.02, 95% CI 1.00-1.04) and in-centre dialysis treatment locality (HR 2.04, 95% CI 1.19-3.45). CONCLUSION: The low posterior approach for internal jugular vein tunnelled catheter insertion is effective and safe. We demonstrated a 12-month catheter survival rate of 68%. Further research comparing the low posterior approach with other internal jugular vein cannulation techniques is warranted.

Interventional nephrology in peritoneal dialysis: Best practice report of the Peritoneal Dialysis Project Group of the Italian Society of Nephrology.

The procedure of peritoneal dialysis (PD) catheter placement is of utmost importance for a good outcome of peritoneal dialysis. Currently, catheters are mainly placed by surgeons and interventional nephrologists. Still, there is a lack of trained personnel in many dialysis units, which can impair the efficiency of PD units and reduce the patients' possibility to enter a PD programme. The Italian Society of Nephrology has endorsed a practical core curriculum for interventional nephrology in PD available on the Society website, which is here reported for the wider nephrology community. The topics addressed are the hernias of the abdominal wall, catheter placement with standard surgical open technique, basic video-laparoscopy, advanced video-laparoscopy, video-laparoscopic cholecystectomy and catheter placement, cuff-shaving and video-laparoscopy in catheter malfunction.

Nephrology Partnership for Advancing Technology in Healthcare (N-PATH) program: the teachers' perspective.

The N-PATH (Nephrology Partnership for Advancing Technology in Healthcare) program concluded with the 60th European Renal Association 2023 Congress in Milan, Italy. This collaborative initiative aimed to provide advanced training in interventional nephrology to young European nephrologists. Funded by Erasmus+ Knowledge Alliance, N-PATH addressed the global burden of chronic kidney disease (CKD) and the shortage of nephrologists. CKD affects >850 million people worldwide, yet nephrology struggles to attract medical talent, leading to unfilled positions in residency programs. To address this, N-PATH focused on enhancing nephrology education through four specialized modules: renal expert in renal pathology (ReMAP), renal expert in vascular access (ReVAC), renal expert in medical ultrasound (ReMUS) and renal expert in peritoneal dialysis (RePED). ReMAP emphasized the importance of kidney biopsy in nephrology diagnosis and treatment, providing theoretical knowledge and hands-on training. ReVAC centred on vascular access in haemodialysis, teaching trainees about different access types, placement techniques and managing complications. ReMUS recognized the significance of ultrasound in nephrology, promoting interdisciplinary collaboration and preparing nephrologists for comprehensive patient care. RePED addressed chronic peritoneal dialysis, offering comprehensive training in patient selection, prescription, monitoring, complications and surgical techniques for catheter insertion. Overall, N-PATH's strategy involved collaborative networks, hands-on training, mentorship, an interdisciplinary approach and the integration of emerging technologies. By bridging the gap between theoretical knowledge and practical skills, N-PATH aimed to revitalize interest in nephrology and prepare proficient nephrologists to tackle the challenges of kidney diseases. In conclusion, the N-PATH program aimed to address the shortage of nephrologists and improve the quality of nephrology care in Europe. By providing specialized training, fostering collaboration and promoting patient-centred care, N-PATH aimed to inspire future nephrology professionals to meet the growing healthcare demands related to kidney diseases and elevate the specialty's status within the medical community.

Nephrology Partnership for Advancing Technology in Healthcare (N-PATH) Erasmus+ project: The Renal Expert in Vascular Access (REVAC) module.

The Renal Expert in Vascular Access (REVAC) is one of the four modules of the Nephrology Partnership for Advancing Technology in Healthcare (N-PATH) project, the first European-wide advanced training course in diagnostics and interventional nephrology, funded by Erasmus+ Knowledge Alliance, a European Commission program. The N-PATH primary goal was to train 40 young European nephrologists in both theoretical knowledge and practical skills related to interventional nephrology. The REVAC module focused on the crucial aspects of vascular access (VA) care in nephrology practice, as a complementary training path to the actual residency program. The aim was to provide nephrology fellows with comprehensive knowledge and skills related to VA management. The methodology was based on face-to-face meetings and online learning, modern facilities, experienced tutors, cutting edge simulators, augmented reality tools by means of a multidisciplinary international faculty and hands-on-courses. A feedback survey reported the experience of fellows who attended the REVAC module, confirming the positive impact on their ongoing nephrology training. We are confident that this project will revitalize their nephrology careers and will help training the next generation of nephrologists; they will be able to manage VA needs with the help of multi-disciplinary teams to safely optimize the care of hemodialysis patients.

Management of vascular access inflow-outflow imbalance: A bimodal approach.

A more accurate descriptive and clinically useful diagnosis based upon pathophysiology for what is commonly referred to as venous outflow stenosis is inflow-outflow imbalance. In these cases, the total outflow capacity of the AV access is inadequate to handle the inflow volume (Qa) without an increase in pressure. The relative inadequacy of the access outflow capacity in comparison to Qa results in increased outflow resistance and a proportional increase in intraluminal pressure. The clinical indicators associated with venous stenosis are the resulting manifestations of this imbalance. The point at which this occurs is dependent upon variations in these two parameters-Qa and outflow resistance. The variations in these two parameters are considerable and reciprocal. Excessive Qa results in or can lead to an entire list of serious problems that adversely affect patient morbidity and mortality. Most studies dealing with AV access Qa reduction have been for the treatment of an existing condition rather than its prevention; however, prevention of disease rather than waiting for its development is an important tenet of medical practice. The resulting clinical picture of inflow-outflow imbalance is taken as an indication for corrective treatment. In the past, in most cases this has meant angioplasty to open the outflow if it is reduced; however, this clinical picture may be associated with an excessive Qa and angioplasty in these cases creates the risk for a further increase in Qa. It is the authors' opinion that access flow measurements should be a part of the evaluation of these cases prior to planning treatment. Using this information, a bimodal approach to primary treatment should be adopted involving either angioplasty for cases with a low or normal Qa or flow reduction in cases with an elevated Qa.

Global hemodialysis vascular access care: Three decades of evolution.

The development of vascular access for hemodialysis has come a long way since 1943 when the first hemodialysis treatment was performed in humans by connecting an artery and vein using an external glass canula. Since then, vascular access care has evolved robustly through contributions from numerous countries and professional nephrology societies, worldwide. To understand the global distribution and contribution of different specialties to medical literature on dialysis vascular access care, we performed a literature search from 1991 to 2021 and identified 2768 articles from 74 countries. The majority of publications originated from the United States (41.5%), followed by China (5.1%) and the United Kingdom (4.6%). Our search results comprise of observational studies (43%), case reports/series (27%), review articles (16.5%) and clinical trials (12%). A large proportion of articles were published in Nephrology journals (49%), followed by General Medicine (14%), Surgery (10%), Vascular Medicine (8%), and Interventional Radiology journals (4%). With the introduction of interventional nephrology, nephrologists will be able to assume the majority of the responsibility for dialysis vascular access care and above all maintain a close interdisciplinary collaboration with other specialties to provide optimum patient care. In this review article, we discuss the history, evolving knowledge, challenges, educational opportunities, and future directions of dialysis vascular access care, worldwide.

Feasibility Analysis of Ultrasound-Guided Placement of Tunneled Hemodialysis Catheters.

Introduction: Radiographic fluoroscopy is the current standard for placement of tunneled central venous catheters (CVCs) for hemodialysis. Radiographic fluoroscopy requires structural and personnel infrastructure and exposes the patient to ionizing radiation. Here, we investigate the feasibility of solely ultrasound-guided placement of tunneled central venous dialysis catheters (USCVCs). Methods: We evaluated prospectively collected single-center data regarding safety and catheter function of 134 consecutive patients who underwent USCVC implantation between 2020 and 2021. We used the inset guidewire to visualize the position of the catheter tip. In the case of inadequate visibility by ultrasound, we used intracardiac electrocardiography (ECG) recording or agitated saline. A total of 1844 catheter days were assessed. The optimal CVC position was defined as being within the upper right atrium (URA) and middle to deep right atrium. Results: Of the 134 USCVCs, 87% were placed on the right side. The primary success rate for optimal tip position and catheter function was 98%. Of the USCVCs, 97% were placed solely by ultrasound. Regarding positioning, 6% were in the vena cava superior zone, 70% in the URA and 24% in the middle to deep right atrium, resulting in a rate of 94% with optimal positioning. Effective blood flow averaged 292 ± 39 ml/min. There were no immediate procedure-associated complications. Conclusion: Placement of CVC for hemodialysis solely by ultrasound is an effective alternative to fluoroscopy-assisted placement.

Evaluation of hemodialysis vascular access. Perspective from Mexico.

Chronic kidney disease (CKD) has become a global health problem. In 2019, it was related to 2.53% of general global mortality (2.35-2.66%); in the same year, in Latin America, mortality related to CKD reached 5.25% (4.92-5.49%), with an annual increase of 3.37%, proving increased mortality of 102% between 1990 and 2017. A nephrology specialty in Mexico recently fulfilled its first 50 years. Despite being relatively young, nephrologists are interested in "new" sub-specialties of nephrology and learning novel techniques and problem-solving skills. Our group is the first in our country to focus solely and exclusively on comprehensive VA care and we want to position ourselves as the first Mexican interdisciplinary group focused on vascular access (GIMEXAV).

Implementing an Interdisciplinary Procedure Curriculum.

INTRODUCTION: This curriculum was designed to improve access to procedures for our internal medicine residents. METHODS: We created an interdisciplinary procedure course (IDPC) composed of two simulation sessions and a one-week procedural rotation supervised by multiple specialties including nephrology, cardiology, cardiothoracic anesthesiology, general anesthesiology, and interventional radiology. After the course, residents completed two surveys documenting the number of procedures and their level of confidence on a Likert scale (1 = very unconfident to 5 = very confident) prior to and after completing the curriculum. RESULTS: Sixteen residents participated in the course from September 2021 to June 2022. The collective number of procedures performed by these 16 residents increased from 176 to 343 after a one-week rotation. For arterial lines, the proportion of residents that reported an improvement in confidence scores was 0.44 (95% confidence interval 0.23 to 1, p-value of 0.60). The proportion of residents that had an increase in their confidence performing central lines was 0.63 (95% confidence interval 0.39 to 1, p-value of 0.23). For intubations, the proportion of residents that reported an improvement in confidence was 0.94 (95% confidence interval 0.72 to 1, p-value of 0.0006). CONCLUSION: By collaborating with multiple specialties, residents almost doubled the number of procedures performed during training and reported an increased level of confidence in procedural performance for airway intubation. We learned residents want to improve their access to procedures and described a curriculum that was easily implemented.

Comparing outcomes of tunnelled dialysis catheter insertions and exchanges with or without fluoroscopy.

BACKGROUND/OBJECTIVE: To study the safety and outcome profiles of tunnelled dialysis catheter (TDC) insertions and exchanges with fluoroscopy versus without fluoroscopy. METHODS: This was a retrospective cohort study of all TDC insertions or exchanges performed at our centre, between January 2017 and December 2017. Patient demographics, laboratory results and catheter placement information were obtained from electronic records. Immediate technical success, early and late catheter associated complications were collected. Outcomes for TDC inserted with or without fluoroscopy were statistically analysed. RESULTS: A total of 351 TDC insertions and 253 TDC exchanges were performed. Out of 351 TDC insertions, 261 were done with fluoroscopy while 90 were done without. Out of 253 TDC exchanges, 219 were done with fluoroscopy while 34 were done without. For both TDC insertions and exchanges, there were no significant differences in complication rates when done with or without fluoroscopy. Mean duration of catheter patency was longer for TDC inserted without fluoroscopy, after adjusting for site of insertion and presence of previous TDC. CONCLUSIONS: The technique of inserting TDC in the right internal jugular vein (IJV) without fluoroscopy is a safe and effective method in selected patients. This supports the practice of performing the procedure without fluoroscopy, especially in institutions where fluoroscopy facilities are not readily available. This potentially translates into reduced healthcare resources and hospitalisation days, which is particularly valuable in times of limited resources such as the current Coronavirus Disease 2019 (COVID-19) pandemic.

Minimally invasive peritoneal access: A new approach of catheter placement for peritoneal dialysis.

BACKGROUND: Catheter implantation techniques for peritoneal dialysis (PD) have advanced significantly in recent years. We aimed to analyze the survival and associated complications of catheters inserted using a new technique that is guided by ultrasound and fluoroscopy and requires minimal tissue dissection. The procedure was performed by nephrologists in the outpatient basis, we compared these results of the minimally invasive insertion with traditional implantation using trocars. METHODS: A total of 152 PD catheters were placed in 152 patients with stage 5 chronic kidney disease; 62.5% of the patients were men, with a mean age of 56.6 ± 18.5 years. The following two methods were used: minimally invasive insertion (MI group, n = 73) and trocar insertion (T group, n = 79). Patients in both the groups were followed prospectively for 26 months from the date of the first implantation. RESULTS: Gender, age, and prevalence of diabetes mellitus were not significantly different between the groups, while the body mass index, presence of obesity, and abdominal scars from previous surgeries were higher in the MI group (p = 0.021). The incidence of catheter dysfunction was lower in the MI group compared to group T (6.8% vs 20.3%; p = 0.019). Exit site infection was also lower with the new technique (4.1% vs. 18.9%; p = 0.005). Further, the cumulative incidence of peritonitis also reduced with MI (p = 0.034). Finally, the overall catheter survival at 1 year was 89%, which has been shown as higher in group MI (95% vs 82% in group T; p = 0.025). CONCLUSION: The MI technique for catheter insertion showed low complication rates and excellent catheter survival as compared to traditional implantation methods; thus, it may be an alternative method for PD catheter placement.

Short-Term Mortality Associated with Outpatient Vascular Access Restoration Procedures.

This study confirms the safety of endovascular interventions for thrombosis of hemodialysis access in outpatient and office-based settings.Risk of death in the week after vascular access procedure was not associated with hemodialysis access type (fistula versus graft).