A central venous catheter, or CVC, is a flexible tube inserted into a large vein to carry blood to and from a dialysis machine when a patient’s kidneys can no longer filter waste on their own. CVCs are the fastest way to start hemodialysis, often placed within hours at the bedside, but they carry higher infection and complication rates than the other two access options: arteriovenous fistulas and arteriovenous grafts. Despite those risks, roughly a third of people on maintenance hemodialysis in the United States still rely on a catheter, and for some patients it remains the most practical choice.
When and Why a CVC Is Used
Most people do not plan to start dialysis on a specific date. Kidney function can decline gradually over months or suddenly over days, and when someone needs hemodialysis urgently, there is no time to create and mature a surgical fistula, a process that takes weeks to months. A CVC bridges that gap. Nontunneled catheters are the go-to for acute situations, designed for short-term use measured in days to a few weeks. Tunneled catheters, which have a fabric cuff that anchors under the skin and discourages bacteria from migrating inward, are meant for longer use and can remain functional for months or even years when well maintained.1PubMed Central. Practical Aspects of Nontunneled and Tunneled Hemodialysis Catheters
CVCs also serve patients whose veins cannot support a fistula or graft, people with severe heart failure where the extra cardiac workload of a fistula would be dangerous, or individuals who have exhausted other access sites after years of dialysis. In some cases, a catheter is placed temporarily while a newly created fistula matures, then removed once the fistula is ready.
Where the Catheter Goes
The right internal jugular vein, running along the right side of the neck, is the preferred insertion site for both tunneled and nontunneled dialysis catheters. It offers a relatively straight path down into the superior vena cava and right atrium, which means fewer kinks and better blood flow during treatment. For nontunneled catheters placed in an emergency, the femoral vein in the groin is the second choice; for tunneled catheters intended for longer use, the left internal jugular is the backup.2PubMed Central. Practical Aspects of Nontunneled and Tunneled Hemodialysis Catheters
The subclavian vein, which runs beneath the collarbone, was once commonly used but has fallen out of favor for dialysis. Catheters placed there carry a well-documented risk of central vein stenosis, a narrowing of the vessel wall that can make it difficult or impossible to create a working fistula or graft in the arm on that side later on.3PubMed Central. Central vein stenosis in hemodialysis vascular access: clinical manifestations and contemporary management strategies One multi-site comparison found the subclavian route had the highest overall incidence of complications, including stenosis and collateral vein formation, while the internal jugular emerged with the fewest problems.4Journal of Population Therapeutics and Clinical Pharmacology. Comparison Among Internal Jugular Vein, Femoral Vein and Subclavian Vein Double Lumen Catheter Cannulation, Catheter Related Infections and Complications in Hemodialysis Patients That said, the picture is not perfectly settled. A large ICU trial found that the subclavian site actually had lower rates of short-term catheter-related bloodstream infection and deep vein thrombosis compared with the femoral or jugular sites, though it studied critically ill patients broadly, not exclusively dialysis patients.5PubMed. We still go for the jugular: implications of the 3SITES central venous catheter study for nephrology In nephrology practice, the long-term risk of stenosis tips the balance decisively away from the subclavian route when future fistula creation is on the table.
How Placement Works
Ultrasound guidance during insertion has become standard practice. Real-time imaging lets the clinician see the vein, the needle, and nearby structures like the carotid artery, which substantially reduces mechanical complications such as accidental artery puncture or pneumothorax.6PubMed Central. Practical Aspects of Nontunneled and Tunneled Hemodialysis Catheters In one large consecutive series using routine ultrasound for tunneled catheter placement, no cases of pneumothorax or hemothorax occurred, though a small number of patients needed minor revision for catheter mispositioning.7PubMed. Routine use of ultrasound to avert mechanical complications during placement of tunneled dialysis catheters for hemodialysis
For tunneled catheters, fluoroscopy (real-time X-ray) has traditionally been used to guide the catheter tip into the right atrium, where blood flow is strongest. A study comparing tunneled catheters placed with and without fluoroscopy found that complication rates and long-term function were comparable between the two approaches, suggesting that ultrasound-only placement is a safe alternative in experienced hands.8PubMed Central. Safety and durable patency of tunneled hemodialysis catheter inserted without fluoroscopy Getting the tip position right matters: computational modeling of blood flow inside the right atrium has shown that placing the catheter tip at mid-atrium level, with the outflow opening facing toward the center of the chest, reduces recirculation of already-filtered blood back into the machine.9PLoS ONE. Computational fluid dynamics of the right atrium: Assessment of modelling criteria for the evaluation of dialysis catheters
The Infection Problem
Infection is the most serious day-to-day risk of dialysis through a catheter. Bacteria, most commonly Staphylococcus aureus, can colonize the catheter surface and form biofilms, sticky communities of microbes that are extremely difficult for the immune system or antibiotics to penetrate.10PubMed Central. Mechanisms of microbial colonization in biofilm-associated infections of hemodialysis catheters and advances in surface modification technologies Once a biofilm takes hold, the result is often a catheter-related bloodstream infection, which can progress to sepsis. Infection rates for nontunneled catheters have been reported in the range of about 4 to 7 episodes per 1,000 catheter-days, while tunneled catheters fare somewhat better at roughly 2 to 6 episodes per 1,000 catheter-days.11Bentham Science Publishers / The Open Urology & Nephrology Journal. Central Venous Catheters in Dialysis: The Good, the Bad and the Ugly
Managing these infections creates a difficult balancing act. Removing the catheter is the surest way to eliminate the source of bacteria, but removing it also eliminates the patient’s dialysis access, sometimes at a moment when alternative sites are scarce. Clinicians often attempt to salvage the catheter with systemic antibiotics and antibiotic lock therapy, reserving removal for patients who are critically ill, have complicated infections like endocarditis, or fail to improve.12PubMed Central. Comprehensive management of hemodialysis catheter-related bloodstream infections: a narrative review
Preventing Infections Before They Start
Prevention works better than treatment. The CDC’s core interventions for bloodstream infection prevention in hemodialysis settings have become the standard framework, emphasizing hand hygiene, aseptic technique during catheter access, hub disinfection, and regular staff training audits.13PubMed Central. Prevention of Bloodstream Infections in Patients Undergoing Hemodialysis Implementing structured quality-improvement programs around these interventions can produce dramatic results. One program reported a drop from about 9 infections per 1,000 catheter-days to fewer than 1 per 1,000 catheter-days after standardizing catheter care protocols.14PubMed. Effects of a Quality Improvement Program to Reduce Central Venous Catheter-Related Infections in Hemodialysis Patients
Two additional strategies have strong evidence behind them. Chlorhexidine-impregnated dressings applied over the catheter exit site cut infection rates by roughly half in a multi-center quality improvement project, with one phase showing reductions as steep as 86% at intervention sites.15PubMed. Chlorhexidine-impregnated transparent dressings decrease catheter-related infections in hemodialysis patients: a quality improvement project And antimicrobial lock solutions, which are instilled into the catheter lumens between dialysis sessions to sit inside the tubing and kill or inhibit bacteria, have been studied extensively. Taurolidine-citrate locks, in particular, cut catheter-related bloodstream infections by about 70% compared to standard heparin locks across pooled randomized trials.16Journal of Hospital Infection. Efficacy of taurolidine containing lock solutions for the prevention of central venous catheter-related bloodstream infections: a systematic review and meta-analysis of randomized controlled trials The tradeoff is a modest, non-significant trend toward more catheter clotting with taurolidine-citrate compared to heparin, since heparin’s blood-thinning properties help keep the lumen clear.17PubMed Central. Is Taurolidine-citrate an effective and cost-effective hemodialysis catheter lock solution? A systematic review and cost-effectiveness analysis
Clotting and Catheter Dysfunction
A catheter that does not deliver enough blood flow for effective dialysis is called dysfunctional, and clotting is the most common culprit. Fibrin, the protein that forms the scaffold of blood clots, deposits preferentially around the catheter’s side holes, where the blood flow is most turbulent. Simulations of blood flow inside dialysis catheters show that side holes create eddies and flow separation zones, and the wall shear stress in those areas is high enough to trigger fibrin deposition.18PubMed. Blood flow in hemodialysis catheters: a numerical simulation and microscopic analysis of in vivo-formed fibrin Microscopy of clots removed from actual patient catheters confirms the picture: fibrin makes up the largest share of the material, with platelet aggregates and trapped blood cells filling in behind it.19PubMed. Hemodialysis catheter thrombi: visualization and quantification of microstructures and cellular composition
Over time, fibrin can also form a sheath that wraps around the outside of the catheter tip like a sleeve, acting as a one-way valve that lets fluid in but blocks outflow. When this happens, the catheter may still draw blood but cannot return it efficiently, leading to alarms on the dialysis machine and shortened treatments.
Salvaging a Clotted Catheter
Before resorting to catheter replacement, clinicians typically try to dissolve the clot with tissue plasminogen activator, commonly called tPA. A systematic review of catheter-instillation studies found that filling each lumen with 1 to 2 milligrams of tPA and letting it dwell for 30 to 60 minutes restored function in roughly 83 to 98 percent of cases.20PubMed. Thrombolysis for restoration of patency to haemodialysis central venous catheters: a systematic review A more recent study reported that about 79% of patients responded after a single tPA dose, and patients who developed recurrent fibrin sheaths months later responded again to repeat dosing.21PubMed Central. Evaluating tissue plasminogen activator (tPA) in dialysis catheter dysfunction: A focus on fibrin sheath and risk factors A pilot study using a slightly different protocol, delivering 2.5-milligram doses systemically through the catheter rather than letting the drug dwell, achieved successful completion of the dialysis session in over 80% of attempts across different catheter sites, with no bleeding complications.22Dialysis & Transplantation. Low-dose tPA for hemodialysis catheter clearance
When tPA fails or the catheter keeps clotting despite repeated treatments, options include exchanging the catheter over a guidewire so the patient does not need a new puncture site, or stripping the fibrin sheath with a snare device threaded through a separate vein. These interventions buy time, but recurrent dysfunction is a signal that transitioning to a fistula or graft should be reconsidered if it is anatomically feasible.
Central Vein Stenosis
One of the more insidious long-term consequences of catheter use is stenosis of the central veins. The catheter rests against the vessel wall for weeks or months, causing low-grade endothelial injury. The body responds with smooth muscle proliferation, microthrombi formation, and progressive thickening of the vein wall, which can eventually narrow or block the vessel.23Frontiers in Nephrology. Central vein stenosis in hemodialysis vascular access: clinical manifestations and contemporary management strategies – Section: Pathomechanisms of central venous stenosis A narrowed central vein creates venous hypertension downstream, leading to arm swelling, prolonged bleeding after needle removal during fistula dialysis, and high recirculation rates that undermine dialysis adequacy.24PubMed Central. Central vein stenosis in hemodialysis vascular access: clinical manifestations and contemporary management strategies
This is a major reason why guidelines urge placing catheters on the opposite side from a planned or maturing fistula, and why subclavian catheters are avoided whenever possible. Once central vein stenosis develops, treatment typically involves balloon angioplasty or stenting, but recurrence rates are high, and the condition can permanently limit future access options.
How CVCs Compare to Fistulas and Grafts
The outcomes gap between catheters and surgically created access is substantial. A meta-analysis comparing the three access types found that CVCs significantly increased all-cause mortality and infection-related mortality compared to arteriovenous fistulas.25PubMed Central. Mortality outcomes associated with vascular access types in hemodialysis for ESRD: a systematic review and meta-analysis A large U.S. study quantified the sepsis risk: after adjusting for other factors, catheter users were about 80% more likely to develop sepsis within three years than fistula users, and once sepsis occurred, one-year mortality was nearly double for catheter patients compared to fistula patients.26PubMed. Incidence and risk factors of sepsis in hemodialysis patients in the United States
The financial burden follows the same pattern. In a study tracking access-related costs among patients who started dialysis with a catheter, those who remained on a catheter had the highest median annual access-related cost, roughly $29,000, driven largely by hospitalizations for catheter-related bloodstream infections.27PubMed Central. The Clinical and Economic Effect of Vascular Access Selection in Patients Initiating Hemodialysis with a Catheter Quality of life takes a hit as well. A multicenter study found that patients dialyzing through a fistula reported higher scores in physical functioning, general health, and social functioning compared to those using a permanent catheter, likely reflecting the cumulative burden of infection worry, care restrictions, and activity limitations that come with catheter dependence.28PubMed Central. Patient Perceptions of Vascular Access and Quality of Life in Maintenance Hemodialysis: A Multicenter Study on Patient-Centered Outcomes
The Shift from “Fistula First” to Individualized Planning
For years, U.S. policy was shaped by the Fistula First Initiative, which pushed to maximize fistula use across the board. The program succeeded in raising national fistula rates and reducing catheter dependence, but it also drew criticism for applying a one-size-fits-all approach to a medically diverse population.29PubMed Central. Fistula First Initiative: Historical Impact on Vascular Access Practice Patterns and Influence on Future Vascular Access Care In 2019, national guidelines moved to an “ESKD Life-Plan” model that prioritizes matching the access type to the individual patient’s needs, comorbidities, vascular anatomy, and life expectancy rather than defaulting to a fistula for everyone.30PubMed. Slowly moving the needle away from Fistula First
Updated KDOQI guidelines still recommend a fistula or graft over a catheter when consistent with the patient’s treatment goals, based on the lower infection and hospitalization rates. But they now explicitly acknowledge that the evidence for choosing between access types based on mortality alone is weaker than commonly assumed, and that patient preference, surgical risk, and quality of life should carry real weight in the decision.31Brazilian Journal of Nephrology. Is the Fistula First Approach still valid?
CVCs in Older and Frail Patients
The calculus changes for elderly patients, and this is where the individualized approach matters most. Older adults have lower survival rates on dialysis regardless of access type, and fistulas in this group fail to mature more often because of poor vein quality and arterial disease. Recent evidence suggests that dialysis survival rates are comparable between fistulas and tunneled catheters in certain subgroups of elderly patients, particularly those with limited life expectancy and significant comorbidities.32PubMed. Looking Beyond “Fistula First” in the Elderly on Hemodialysis
One population-based cohort study of elderly patients found that pre-emptive fistula creation, done before dialysis starts, still offered benefits in decreased mortality and infection rates. But for patients who had to start dialysis urgently on a catheter, the recommendation was to convert to a fistula only if life expectancy exceeded roughly four months. For those with shorter prognoses, the study concluded that patient preference, surgical risk, and end-of-life quality should drive the decision about whether to continue dialyzing through a catheter.33Journal of Vascular Surgery. Vascular access for hemodialysis in the elderly Putting a frail 85-year-old through fistula surgery and weeks of maturation to gain a marginal survival advantage that may never materialize is a real harm, and the newer guidelines give clinicians explicit permission to weigh that honestly.
Next-Generation Catheter Surfaces
Because so many catheter complications trace back to what happens on the catheter surface, a growing body of research is focused on re-engineering that surface at the molecular level. Existing catheters are made of silicone or polyurethane, materials that blood proteins and bacteria readily stick to. Researchers have experimented with coatings that release nitric oxide, a molecule the body naturally uses to keep blood vessels slippery and inhospitable to clots. One approach layers an antimicrobial peptide alongside a nitric oxide-generating compound on the catheter surface, creating a dual defense that resists both bacterial adhesion and platelet activation.34Bioactive Materials. Engineering anti-thrombogenic and anti-infective catheters through a stepwise metal-catechol-(amine) surface engineering strategy These technologies are still largely in the laboratory and animal-testing phases, but they represent the most promising direction for making catheters fundamentally safer rather than relying solely on external infection-prevention bundles and clot-busting drugs after problems develop.35PubMed Central. A review of evolving dialysis catheter technologies
Other design innovations over the past decade have focused on tip geometry. Various split-tip, symmetric-tip, and step-tip configurations aim to reduce recirculation and improve flow rates, but head-to-head clinical comparisons have not shown any single design to be clearly superior.36PubMed Central. Practical Aspects of Nontunneled and Tunneled Hemodialysis Catheters The field’s hope is that combining better tip design with bioactive surface coatings will eventually produce a catheter that closes the outcomes gap with fistulas, at least for patients who have no surgical alternative.