Taurolidine and Heparin as Catheter Lock Solution for Central Venous Catheters in Hemodialysis.

BACKGROUND: Chronic kidney disease can lead to end-stage renal disease, and the prevalence is increasing. Many patients starting hemodialysis require central venous catheters (CVCs). Catheter-related bloodstream infections (CRBSIs) are a common complication and lead to significant morbidity and mortality. Interventions to prevent CRBSI include antimicrobial lock therapy but concern for the development of antimicrobial resistance and adverse effects. Nonantimicrobial antiseptics as catheter lock solutions have also been used. Taurolidine and heparin catheter lock solution is first approved by the Food and Drug Administration for the prevention of CRBSI in patients on hemodialysis. Taurolidine has a unique mechanism of action and favorable safety profile. MECHANISM OF ACTION, PHARMACODYNAMICS, AND PHARMACOKINETICS: Taurolidine and heparin catheter lock solution have both antimicrobial and anticoagulant properties. Taurolidine is derivative of the amino acid taurine, and heparin is derived from porcine intestinal mucosa. Taurolidine not only damages microbial cell walls but also prevents the adherence of microorganisms to biological surfaces, preventing biofilm formation. Taurolidine and heparin catheter lock solution is intended to be used intraluminally within the catheter and should be aspirated. Because it is used locally, limited pharmacokinetic and pharmacodynamic data are available. CLINICAL TRIALS: The LOCK-IT-100 trial is a randomized, double-blind, phase 3 study, which included 795 end-stage renal disease patients on hemodialysis with CVC. Taurolidine and heparin was compared with the control heparin alone. The results of the study showed a 71% risk reduction in CRBSI for taurolidine and heparin arm (95% confident interval, 38%-86%, P = 0.0006). Other studies have also shown that taurolidine lock solution leads to decreased CRBSI episodes. Several systematic reviews and meta-analysis consisted of taurolidine in adult, and pediatric populations also showed reduction in the incidence of CRBSIs. THERAPEUTIC ADVANCE: Taurolidine and heparin lock solution represents a novel preventive strategy for those undergoing hemodialysis through a CVC by reducing the risk of CRBSI. This is significant progress because there are no other similar options available for patients for whom catheters are the only options for their life-saving treatment.

An Improvised Cost-Effective Repair Technique for Management of Broken Luer Connections of Tunneled Dialysis Catheter and Salvage Existing Catheter.

Mechanical problems like break or crack in Luer connectors or hubs, clamps, and tubings are common non-infectious complications of tunneled dialysis catheters (TDC), which may lead to other TDC complications and the need to insert a new catheter. These can be tackled using TDC repair kits or spare parts, which are often not available, resulting in the insertion of a new TDC that increases morbidity, TDC-related procedures, and healthcare costs. We discuss two cases of broken Luer connections of TDC, which were managed by exchanging the broken Luer connector of TDC with the similar Luer connector of a temporary dialysis catheter. Both the repaired TDCs are thereafter functioning well. This improvised technique provides an easy, effective, long-lasting option that salvages the existing TDC and reduces the cost factor.

Technical requirements and devices available for long-term hemodialysis in children-mind the gap!

Children requiring long-term kidney replacement therapy are a "rare disease" cohort. While the basic technical requirements for hemodialysis (HD) are similar in children and adults, key aspects of the child's cardiovascular anatomy and hemodynamic specifications must be considered. In this article, we describe the technical requirements for long-term HD therapy for children and the devices that are currently available around the world. We highlight the characteristics and major technical shortcomings of permanent central venous catheters, dialyzers, dialysis machines, and software available to clinicians who care for children. We show that currently available HD machines are not equipped with appropriately small circuits and sensitive control mechanisms to perform safe and effective HD in the youngest patients. Manufacturers limit their liability, and health regulatory agencies permit the use of devices, only in children according to the manufacturers' pre-specified weight limitations. Although registries show that 6-23% of children starting long-term HD weigh less than 15 kg, currently, there is only one long-term HD device that is cleared for use in children weighing 10 to 15 kg and none is available and labelled for use in children weighing less than 10 kg anywhere in the world. Thus, many children are being treated "off-label" and are subject to interventions delivered by medical devices that lack pediatric safety and efficacy data. Moreover, recent improvements in dialysis technology offered to adult patients are denied to most children. We, in turn, advocate for concerted action by pediatric nephrologists, industry, and health regulatory agencies to increase the development of dedicated HD machines and equipment for children.

Incorporating a hemodialysis filter into a commercial normothermic perfusion system to facilitate long-term preservation of human split-livers.

BACKGROUND: Normothermic machine perfusion (NMP) allows for the assessment and resuscitation of ex-vivo human livers prior to transplantation. Commercially available NMP systems are closed circuits that accumulate metabolic waste and cytokines over time, potentially limiting organ preservation times. Dialysis has been proposed as a method to remove waste and excess fluid from such systems. This study aimed to demonstrate the utility of integrating dialysis into a commercially available system by quantifying solute removal. METHODS: A dialysis filter was attached in parallel to a commercially available liver perfusion system. Three livers declined for transplantation were split before undergoing long-term NMP with blood using the modified system. During perfusion, dialysate flow rates were set in the range of 100-600 mL/h for short periods of time. At each flow rate, perfusate and spent dialysate samples were collected and analyzed for solute clearance. RESULTS: The addition of dialysis to a commercial NMP system removed water-soluble waste and helped regulate electrolyte concentrations. Interleukin-6 was successfully removed from the perfusate. Solute clearance was proportional to dialysate flow rate. A guide for our perfusion setup was created for the appropriate selection of dialysis flow rates and duration based on real-time perfusate composition. CONCLUSIONS: Dialysis circuits can efficiently remove waste and regulate perfusate composition, and can be easily incorporated to improve the performance of commercially available systems. Quantification of the effect of dialysis on perfusate composition enables refined dialysis control to optimize electrolyte profiles and avoid the over- or under-correction of key solutes.

Can regional anticoagulation with calcium-free dialysate be extended to maintenance hemodialysis?

BACKGROUND: Regional anticoagulation in hemodialysis avoids the use of heparin, which is responsible for both hemorrhagic and non-hemorrhagic complications. Typically, blood is decalcified by injecting citrate into the arterial line of the extracorporeal circuit. Calcium-free dialysate improves anticoagulation efficacy but requires injection of a calcium-containing solution into the venous line and strict monitoring of blood calcium levels. Recent improvements have made regional anticoagulation with calcium-free dialysate safer and easier. OBSERVATIONS: (1) Adjusting the calcium injection rate to ionic dialysance avoids the risk of dyscalcemia, thus making unnecessary the monitoring of blood calcium levels. This adjustment could be carried out automatically by the hemodialysis monitor. (2) As calcium-free dialysate reduces the amount of citrate required, this can be supplied by dialysate obtained from currently available concentrates containing citric acid. This avoids the need for citrate injection and the risk of citrate overload. (3) Calcium-free dialysate no longer needs the dialysate acidification required for avoiding calcium carbonate precipitation in bicarbonate-containing dialysate. CONCLUSIONS: Regional anticoagulation with calcium-free dialysate enables an acid- and heparin-free procedure that is more biocompatible and environmentally friendly than conventional bicarbonate hemodialysis. The availability of specific acid-free concentrates and adapted hemodialysis monitors is required to extend this procedure to maintenance hemodialysis.

Most recently developed polyester polymer alloy dialyzer: A new medium cut-off membrane?

BACKGROUND: New versions of the polyester polymer alloy (PEPA) membrane have appeared over the years, with increases in both the pore size and the amount of polyvinylpyrrolidone (PVP) to optimize hydrophilicity performance. This study aimed to assess the efficacy of the most recently developed PEPA dialyzer, the FDY series, in hemodialysis (HD) modality in terms of uremic toxin removal and albumin loss and to compare it with that of several high-flux dialyzers currently used in HD and post-dilution hemodiafiltration (HDF) treatments. METHODS: A prospective study was carried out in 21 patients. All patients underwent six dialysis sessions with the same routine dialysis parameters; only the dialyzer and/or the dialysis modality varied: FX80 in HD, FDY 180 in HD, Clearum HS17 in HDF, Elisio 19H in HDF, Vitapes 180 in HDF, and FX80 in post-dilution HDF. The reduction ratios (RR) of urea, creatinine, ß2-microglobulin, myoglobin, κFLC, prolactin, α1-microglobulin, α1-acid glycoprotein, λFLC, and albumin were compared intraindividually. Dialysate albumin loss was also measured. RESULTS: Both membranes FDY and FX80 are high-flux dialyzers and are applied here in high-flux HD. The average RR of ß2-microglobulin was slightly lower in the two HD treatments than in the HDF treatments. Comparison of dialysis treatments revealed that the PEPA FDY dialyzer in the HD modality was more effective than the FX80 dialyzer in high-flux HD and was as effective as post-dilution HDF, especially in terms of myoglobin, κFLC, prolactin, α1-microglobulin, and λFLC RRs. The FDY treatments obtained similar albumin RR in blood and slightly higher dialysate albumin loss, although the values were clinically acceptable. CONCLUSIONS: The most recently developed PEPA dialyzers in the HD modality were as effective as all treatments in the HDF modality and were clearly superior to high-flux helixone HD treatment. These results confirm that this dialyzer should be categorized within the medium cut-off (MCO) membrane classification.

Environmentally sustainable design guide for haemodialysis facilities: An Australian and New Zealand society of Nephrology initiative.

Haemodialysis facilities have a large environmental impact due to high energy, water and consumable usage by haemodialysis equipment. As climate change and natural resource scarcity escalate, all the while the number of people requiring dialysis increases, there is an urgent need for dialysis facilities that meet care needs while minimising environmental impact. To address this, the Australian and New Zealand Society of Nephrology engaged an environmental sustainability consulting practise to develop a best practise guide for the environmentally sustainable design and operation of haemodialysis facilities. Four opportunity areas were considered, namely energy, water, waste and resource recovery, and additional sustainability. A total of 28 environmental improvement initiatives were identified. The majority (n = 23) were general measures that could be applied across all healthcare settings, while five were specific to haemodialysis facilities. Recommendations were made regarding specific measures that should be undertaken and/or standards that must be met to achieve the intent of each initiative. These were stratified to enable their application to both existing dialysis facilities and new builds. The lifecycle stage of a haemodialysis facility to which each initiative applied was highlighted, as was its potential impact. This guide provides a tailored and comprehensive resource for the kidney care community to enable the integration of best practise sustainability considerations into both existing and new facilities. If broadly implemented, it has the potential to markedly improve the environmental impact of haemodialysis provision.

Guidewire entrapment in the Chiari network during the insertion of a hemodialysis catheter: a case report.

BACKGROUND: The Chiari network, a remnant of fetal anatomy, consists of a mesh-like structure within the right atrium. With advancements in cardiac interventions, complications associated with the Chiari network have increasingly been reported. However, there are few reports about guidewire or catheter entrapment in the Chiari network during the insertion of a dialysis catheter. CASE PRESENTATION: A 46-year-old male with end-stage renal disease was hospitalized and underwent a digital subtraction angiography-assisted catheterization of the right internal jugular vein tunnel-cuffed dialysis catheter. When the guide wire entered a depth of about 20 cm, it was difficult to advance, manifested as resistance when twisting the guide wire and inability to enter the inferior vena cava. After the peelable sheath was inserted, it was difficult to pull out the guide wire. After repeated attempts to rotate the guide wire, the guide wire was finally pulled out. A fibrous tissue was wrapped around the tip of the guide wire. Its length was 6 cm, with a smooth surface and tough texture. We considered that the tissue we pulled out was most likely a part of a Chiari network. CONCLUSIONS: This case highlights the potential for the Chiari network to complicate surgical procedures, including difficulty with guidewire and catheter manipulation. Attention should be paid to Chiari networks. Echocardiography can be used to identify the Chiari network. During the surgery, forcefully pulling out a stuck guidewire is not suggested, to avoid the risk of tearing the atrial wall and causing pericardial tamponade. An urgent consultation with ultrasound doctors and cardiac surgeons might be helpful in such cases.

Non-tunneled haemodialysis catheter-related blood stream infections and associated factors among first time haemodialysis patients: a prospective study from a tertiary care hospital in Sri Lanka.

BACKGROUND: A significant number of patients require non-tunneled haemodialysis catheters (NTHCs) in the event of an urgent need for immediate haemodialysis in developing countries. Catheter-related bloodstream infections (CRBSIs) are a major concern in haemodialysis, but there is a lack of local epidemiological data. This study aimed to determine the incidence of CRBSI, causative agents and associated risk factors in a tertiary care hospital in Sri Lanka. METHODS: A prospective study was conducted at the dialysis unit of Colombo South Teaching Hospital, Sri Lanka from December 2019 to August 2020. Adult patients who had haemodialysis for the first time with NTHCs were included. RESULTS: Of 149 dialysis patients (104-jugular vein and 45-femoral vein, mean age 58 ± 13.7 years, mean duration of catheterization 7.9 ± 3.4 days), the incidence of CRBSI was 13.58 per 1000 catheter days. Serum albumin levels, capillary blood sugar levels at admission, haemoglobin levels and duration of catheterization were significantly associated with CRBSI. Prescence of diabetes and patients with ESRD who started routine haemodialysis had a significantly higher risk of CRBSI. Gram-positive bacteria were the most common microorganisms associated with CRBSI (87.5%). CONCLUSIONS: Our results show high rates of infection with temporary vascular catheters in Sri Lanka, mainly due to Gram-positive bacteria. Diabetes mellitus, duration of catheterisation, low serum albumin, haemoglobin level and CBS on admission were identified as significant risk factors for CRBSI. Management strategies tailored to specific centers should be established in the nation to optimise catheter care and to monitor local microbiology for appropriate empirical antimicrobial treatment.

3D porous structure imaging of membranes for medical devices using scanning probe microscopy and electron microscopy: from membrane science points of view.

The evolution of hemodialysis membranes (dialyzer, artificial kidney) was remarkable, since Dow Chemical began manufacturing hollow fiber hemodialyzers in 1968, especially because it involved industrial chemistry, including polymer synthesis and membrane manufacturing process. The development of hemodialysis membranes has brought about the field of medical devices as a major industry. In addition to conventional electron microscopy, scanning probe microscopy (SPM), represented by atomic force microscopy (AFM), has been used in membrane science research on porous membranes for hemodialysis, and membrane science contributes greatly to the hemodialyzer industry. Practical studies of membrane porous structure-function relationship have evolved, and methods for analyzing membrane cross-sectional morphology were developed, such as the ion milling method, which was capable of cutting membrane cross sections on the order of molecular size to obtain smooth surface structures. Recently, following the global pandemic of SARS-CoV-2 infection, many studies on new membranes for extracorporeal membrane oxygenator have been promptly reported, which also utilize membrane science researches. Membrane science is playing a prominent role in membrane-based technologies such as separation and fabrication, for hemodialysis, membrane oxygenator, lithium ion battery separators, lithium recycling, and seawater desalination. These practical studies contribute to the global medical devices industry.

Comparison of feasibility and effectiveness of tunneled dialysis catheter placement with or without DSA guidance: a propensity score-matched cohort study.

BACKGROUND: In some resource-limited regions, the placement of tunneled dialysis catheters (TDC) is often preferred under ultrasound guidance rather than fluoroscopy. This study compared ultrasound-and digital subtraction angiography-guided (DSA)-guided TDC in renal replacement therapy. METHODS: This retrospective cohort study included all TDC placements performed at our hospital between January 2020 and October 2022. We utilized 1:1 propensity score matching (PSM) to balance the demographic and clinical characteristics of the DSA-guided and ultrasound-guided groups. Dialysis prescriptions and actual dialysis completion were assessed using intraclass correlation coefficients (ICC). Multivariable logistic regression analyses determined the risk factors for early termination of dialysis. The differences in adverse events, catheter function, and catheter tip position were evaluated between the two groups. RESULTS: The study included 261 patients (142 in the DSA-guided group and 119 in the ultrasound-guided group). After PSM, 91 patients were included in each group, with no significant baseline differences (p > .1). Both groups achieved adequate catheter blood flow and ultrafiltration volumes without deviations from dialysis prescriptions (ICC ≥ 0.75). The DSA-guided group had fewer early dialysis terminations than the ultrasound-guided group (3.3 vs. 12.0%, p = .026). The position of the catheter tip in the right atrium was more consistent in the DSA-guided group (100 vs. 74.2%, p < .001). CONCLUSION: Hemodialysis catheters inserted under DSA guidance exhibited superior performance compared to those inserted under ultrasound guidance, primarily due to more accurate catheter tip positioning. DSA guidance is recommended when ensuring optimal catheter tip placement.

Dysbiosis and Staphylococcus species over representation in the exit site skin microbiota of hemodialysis patients carrying tunneled cuffed central venous catheter.

OBJECTIVES: Hemodialysis patients with end-stage renal disease (ESRD) are susceptible to infections and dysbiosis. Catheter-related infections are typically caused by opportunistic skin pathogens. This study aims to compare the skin microbiota changes around the exit site of tunneled cuffed catheters (peri-catheter group) and the contralateral site (control group). METHODS: ESRD patients on hemodialysis were recruited. The skin microbiota were collected with moist skin swabs and analyzed using high-throughput sequencing of the 16S rDNA V3-V4 region. After denoising, de-replication, and removal of chimeras, the reads were assigned to zero-radius operational taxonomic units (ZOTU). RESULTS: We found significantly reduced alpha diversity in the peri-catheter group compared to the control group, as indicated by the Shannon, Jost, and equitability indexes, but not by the Chao1 or richness indexes. Beta diversity analysis revealed significant deviation of the peri-catheter microbiota from its corresponding control group. There was an overrepresentation of Firmicutes and an underrepresentation of Actinobacteria, Proteobacteria, and Acidobacteria at the phylum level in the peri-catheter group. The most abundant ZOTU (Staphylococcus spp.) drastically increased, while Cutibacterium, a commensal bacterium, decreased in the peri-catheter group. Network analysis revealed that the skin microbiota demonstrated covariance with both local and biochemical factors. CONCLUSIONS: In conclusion, there was significant skin microbiota dysbiosis at the exit sites compared to the control sites in ESRD dialysis patients. Managing skin dysbiosis represents a promising target in the prevention of catheter-related bacterial infections.

A Miniaturized Dual-Band Circularly Polarized Implantable Antenna for Use in Hemodialysis.

Hemodialysis is achieved by implanting a smart arteriovenous graft (AVG) to build a vascular pathway, but reliability and stability in data transmission cannot be guaranteed. To address this issue, a miniaturized dual-band circularly polarized implantable antenna operating at 1.4 GHz (for energy transmission) and 2.45 GHz (for wireless telemetry), implanted in a wireless arteriovenous graft monitoring device (WAGMD), has been designed. The antenna design incorporates a rectangular serpentine structure on the radiation surface to reduce its volume to 9.144 mm3. Furthermore, matching rectangular slots on the radiation surface and the ground plane enhance the antenna's circular polarization performance. The simulated effective 3 dB axial ratio (AR) bandwidths are 11.43% (1.4 GHz) and 12.65% (2.45 GHz). The simulated peak gains of the antenna are -19.55 dBi and -22.85 dBi at 1.4 GHz and 2.45 GHz, respectively. The designed antenna is implanted in a WAGMD both in the simulation and the experiment. The performance of the system is simulated in homogeneous human tissue models of skin, fat, and muscle layers, as well as a realistic adult male forearm model. The measurement results in a minced pork environment align closely with the simulation results.

Medium Cut-Off versus Low-Flux Dialyzers in Hemodialysis Patients with COVID-19: Clinical Outcomes and Reduction in Interleukin-6.

INTRODUCTION: The coronavirus disease 2019 (COVID-19) pandemic has caused extensive morbidity and mortality worldwide. Hemodialysis (HD) patients are both vulnerable to COVID-19 infection and tend to suffer greater disease severity and mortality. This retrospective study aimed to compare medium cut-off (MCO) and low-flux (LF) membrane dialyzers in terms of interleukin-6 (IL-6) reduction, change in inflammatory state, intradialytic complications, and mortality in chronic HD patients with COVID-19. METHOD: HD patients with a confirmed COVID-19 infection were admitted to the hospital for 10-14 days and underwent HD at the COVID-HD unit. Choice of dialyzer membrane used (MCO vs. LF) depended on the primary nephrologist(s). We collected data on demographics, baseline characteristics, laboratory results, diagnosis, treatments, HD prescription, hemodynamic status during HD, and mortality at 14 and 28 days after. RESULTS: IL-6 reduction ratio (RR) in the MCO group was 9.7 (interquartile range, 71.1) percent, which was significantly higher than that of the LF group (RR, -45.7 [interquartile range, 70.2] percent). The incidence rate of intradialytic hypotension in the MCO group was 3.846 events per 100 dialysis hours (95% confidence interval [CI], 1.954-6.856), which was significantly lower than that of the LF group (9.057; 95% CI, 5.592-13.170). Overall, mortality was not significantly different between the two groups. CONCLUSION: The MCO membrane was more effective in removing IL-6 and was better tolerated than the LF membrane. Large, randomized controlled trials are required to confirm the relative benefits of the MCO membrane, especially mortality. However, due to the COVID-19 pandemic, our results suggest that the MCO membrane may be beneficial in chronic HD patients with COVID-19.

Multicenter European real-world utilization of VasQ anastomotic external support device for arteriovenous fistulae.

OBJECTIVE: To evaluate the outcomes of arteriovenous fistulae (AVF), created with VasQ external support device under standard clinical practice across three vascular access clinics. METHODS: This multinational, retrospective study evaluated prospectively collected clinical outcomes of both forearm and upper arm brachiocephalic AVF (BCAVF) created using the VasQ device. Fifty-one AVF patients were pooled from three different vascular access centers in Germany, Italy, and Spain. Postprocedure outcomes were assessed by flow measurement with ultrasound examination in all centers. Primary failure, usability, patency, and intervention rates during the study period were evaluated. RESULTS: Fifty-one VasQ devices were implanted during 37 forearm (36 radiocephalic and 1 ulnar-basilic AVF) and 14 BCAVF procedures. The study population comprised mostly males (73%) and Caucasians (82%), with a mean age of 62.5 years (range, 38-84 years) and mean body mass index of 29.2. One patient died owing to access-unrelated reasons, and one patient was lost to follow-up without AVF assessment after its creation. From the remaining 49, 3 patients had a follow-up of less than 4 weeks and were excluded from maturation, primary failure, and dialysis initiation analysis (because those factors could not be evaluated yet), leaving 46 patients in this evaluation. Maturation was achieved in 91% of patients. The primary failure rate was 9%. A primary patency rate of 77% was observed at 6, 12, and 18 months. The secondary patency rate was 91% at 6 months, and 85% at 12 months and 18 months. Both primary patency and secondary patency did not differ statistically when comparing forearm AVF with BCAVF (P > .25). Successful cannulation was achieved in 86% of patients (32/37) requiring dialysis with a median time from creation to cannulation of 46 days. Of those patients, the functional patency rate was 94%. Five patients underwent seven interventions to maintain or restore patency or functionality, with an overall rate of 0.248 interventions per patient-year. CONCLUSIONS: AVFs created with VasQ external support device demonstrated promising patency and functionality outcomes in multicentric real-world setting across the two most commonly used anatomic locations.

New Devices and Technologies for Hemodialysis Vascular Access: A Review.

In the United States, hemodialysis remains the most common treatment modality for kidney failure, chosen by almost 90% of incident patients. A functioning vascular access is key to providing adequate hemodialysis therapy. Recently, major innovations in devices and technology for hemodialysis vascular access care have rapidly changed the landscape. Novel endovascular devices for creation of arteriovenous fistulas may offer a solution to the barriers encountered in initiating maintenance hemodialysis with a permanent vascular access rather than a central venous catheter (CVC). Furthermore, in the prevalent hemodialysis population, the minimally invasive endovascular arteriovenous fistula procedure should help improve long wait times for vascular access creation, which remains a major barrier to reducing CVC dependence. Bioengineered grafts are being developed and may offer another option to polytetrafluoroethylene grafts. Early studies with these biocompatible grafts are promising, as additional studies continue to evaluate their clinical outcomes in comparison to cryopreserved or synthetic options. Prolonging the vascular access patency with appropriate use of devices such as drug-coated balloons and stent grafts may complement the novel techniques of creating arteriovenous access. Finally, innovative solutions to treat stenosed and occluded thoracic central veins can provide an approach to creating a vascular access and allow patients with exhausted vasculature to remain on hemodialysis. The robust developments in hemodialysis vascular access are likely to change practice patterns in the near future.

Comparison of Ellipsys Percutaneous and Proximal Forearm Gracz-Type Surgical Arteriovenous Fistulas.

RATIONALE & OBJECTIVE: Percutaneous arteriovenous fistulas (AVF) are created by establishing a proximal forearm anastomosis and offer a safe and reliable vascular access. This study compares the Ellipsys percutaneous AVF with a proximal forearm Gracz-type surgical AVF, chosen for comparison as it is constructed at the same anatomical site. STUDY DESIGN: Retrospective study of prospectively collected clinical data. SETTING & PARTICIPANTS: All vascular access procedures conducted during a 34-month period were reviewed. The study groups comprised 89 percutaneous AVFs and 69 surgical AVFs. EXPOSURE: Percutaneous or surgical AVF placement. OUTCOME: AVF patency, function, and complications. ANALYTICAL APPROACH: Patency rates for each AVF group were evaluated by competing risk survival analysis using a cumulative incidence function. Association of primary, primary assisted, and secondary patency with the AVF groups was examined by Cox proportional hazard models. RESULTS: Technical success was 100% for both groups. Average procedure times were 14 minutes for percutaneous AVFs and 74 minutes for surgical AVFs (P < 0.001). Proximal radial artery (PRA) was used in all percutaneous AVF cases. Inflow for surgical AVFs included radial (30%), ulnar (12%), and brachial (58%) arteries. Outflow veins for both groups were the cephalic and/or basilic veins. Access flow volumes, times to maturation, and overall numbers of interventions per patient-year were not significantly different. Cumulative incidence of primary patency failure at 12 months was lower for surgical AVF (47% vs 64%, P = 0.1), but secondary patency failure was not different between groups (20% vs 12%, P = 0.3). PRA surgical AVFs had similar primary patency (65% vs 64%, P = 0.8) but higher secondary patency failure rates than percutaneous AVFs at 12 months (34% vs 12%, P = 0.04). LIMITATIONS: Retrospective study with a relatively short follow-up period, and not all patients required hemodialysis at the end of study. CONCLUSIONS: Both percutaneous and surgical AVFs demonstrated high rates of technical success and secondary patency. Percutaneous AVFs required shorter procedure times. The rate of intervention was similar. When a distal radial artery AVF is not feasible, percutaneous AVF might offer an appropriate procedure for creating a safe and functional access, maintaining further proximal forearm surgical AVF creation options.

Malfunctioning temporary hemodialysis catheters in patients with novel coronavirus disease 2019.

OBJECTIVE: The hypercoagulability seen in patients with novel coronavirus disease 2019 (COVID-19) likely contributes to the high temporary hemodialysis catheter (THDC) malfunction rate. We aim to evaluate prophylactic measures and their association with THDC patency. METHODS: A retrospective chart review of our institutions COVID-19 positive patients who required placement of a THDC between February 1 to April 30, 2020, was performed. The association between heparin locking, increased dosing of venous thromboembolism (VTE) prophylaxis and systemic anticoagulation on THDC patency was assessed. Proportional hazards modeling was used to perform a survival analysis to estimate the likelihood and timing of THDC malfunction with the three different prophylactic measures. We also determined the mortality, rate of THDC malfunction and its association with d-dimer levels. RESULTS: A total of 48 patients with a mortality rate of 71% were identified. THDC malfunction occurred in 31.3% of patients. Thirty-seven patients (77.1%) received heparin locking, 22 (45.8%) received systemic anticoagulation, and 38 (79.1%) received VTE prophylaxis. Overall, the rate of THDC malfunction was lower at a trend level of significance, with heparin vs saline locking (24.3% vs 54.6%; P = .058). The likelihood of THDC malfunction in the heparin locked group is lower than all other groups (hazard ratio [HR], 0.07; 95% confidence interval [CI], 0.01-0.45]; P = .005). The rate of malfunction in patients with subcutaneous heparin (SQH) 7500 U three times daily is significantly lower than of the rate for patients receiving none (HR, 0.03; 95% CI, 0.001-0.74; P = .032). A trend level significant association was found for SQH 5000 U vs none (P = .417) and SQH 7500 vs 5000 U (P = .059). Systemic anticoagulation did not affect the THDC malfunction rate (P = .240). Higher d-dimer levels were related to greater mortality (HR, 3.28; 95% CI, 1.16-9.28; P = .025), but were not significantly associated with THDC malfunction (HR, 1.79; 95% CI, 0.42, 7.71; P = .434). CONCLUSIONS: Locking THDCs with heparin is associated with a lower malfunction rate. Prospective randomized studies will be needed to confirm these findings to recommend locking THDC with heparin in patients with COVID-19. Increased VTE prophylaxis suggested a possible association with improved THDC patency, although the comparison lacked sufficient statistical power.

Efficacy and Safety of Plastic Cannulae Compared with Metal Needles in the Initial Use of an Arteriovenous Fistulae in Incident Hemodialysis Patients: A Randomized Controlled Study.

INTRODUCTION: Successful cannulation of an arteriovenous fistula (AVF) is important in patients starting hemodialysis (HD). Metal needles have been used for decades, but the usefulness of plastic cannulae has recently been demonstrated as a new technique. METHODS: This was a prospective, randomized, open-label study of incident HD patients. Eligible patients were randomized into 2 groups in a 1:1 ratio (n = 45/group). Maturation of the AVF was confirmed using Doppler ultrasound prior to first needling, and 2 well-trained nurses implemented the AVF cannulation. The primary endpoint was the initial cannulation failure rate, defined as the failure of successful completion of 3 consecutive dialysis sessions. The secondary endpoints were time for hemostasis at the end of HD, degree of patients' pain, degree of cannulation difficulty felt by the nursing staffs, and achieving optimal HD adequacy. RESULTS: The mean elapsed time from AVF creation to the first cannulation was 48.1 ± 16.7 days. A total of 17 cases of cannulation failure occurred, and the failure risk tended to be higher in the metal needle group than the plastic cannula group (hazard ratio 2.6, 95% confidence interval 0.95-7.41) after adjusting for age, gender, comorbidities, and AVF location. The overall incidence of vessel injury was higher and time for hemostasis was significantly longer in the metal group than the plastic group. The use of plastic cannula was associated with a better HD adequacy compared to a metal needle. However, the patients' pain score (p = 0.004) and nursing staff's cannulation difficulty score (p = 0.084) were higher in the plastic group, emphasizing the great importance of practice using plastic cannulae. CONCLUSION: The vascular outcomes of plastic cannulae were much favorable compared to metal needles in incident HD patients. The use of plastic cannulae could be a new and innovative way to improve the quality of dialysis.

Surgeon Factors Have a Larger Effect on Vascular Access Type and Outcomes than Patient Factors.

BACKGROUND AND OBJECTIVES: Though patient factors are frequently linked to hemodialysis vascular access selection and outcomes, variability by surgeon and surgeon specialty may play a role as well. The objective of this study is to examine the extent to which individual surgeons influence selection of vascular access type, removal of tunneled hemodialysis catheter (THC), and repeat vascular access. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: A national claims database was used to identify patients initiating hemodialysis via a THC between 2011 and 2017. Likelihood of repeat AVF/AVG was analyzed using mixed-effects logistic regression. Time from initial arteriovenous fistula (AVF)/graft (AVG) to THC removal and time to repeat AVF/AVG were analyzed using Weibull proportional hazard models. Individual surgeon identifier served as the random effect in all models. RESULTS: 6,908 AVF/AVG met the inclusion criteria: 5366 (78%) AVF and 1,542 (22%) AVG. Surgeon specialty only had a significant influence on access type, with vascular surgeons having 26% greater odds of performing AVG compared to general surgeons (P = 0.006). Relative to the other independent variables, individual surgeon identifier had the greatest magnitude of effect on access type (median odds ratio, 2.36; 95% CI, 2.09-2.72). Individual surgeon identifier had the second greatest magnitude of effect likelihood of THC removal (median hazard ratio, 1.66; 95% CI, 1.58-1.77) and second access (median hazard ratio, 1.83; 95% CI, 1.66-2.05), in both cases second only to the effect of AVG, which was associated with greater likelihood of THC removal (hazard ratio 1.91; 95% CI, 1.77-2.07) and lower likelihood of second access (hazard ratio 0.44; 95% CI, 0.38-0.52). CONCLUSION: Individual surgeons are associated with greater variation in vascular access type and likelihood of repeat access than surgeon specialty and measurable patient demographics/co-morbidities. Future research should focus on identifying which surgeon factors are associated with improved outcomes.