Statement of significance
Central venous access devices are indispensable in dialysis and cancer care, yet their long-term performance remains limited by infection and thrombosis. This review highlights that these complications are critically shaped by biomaterial composition and surface properties at the blood–device interface. By integrating evidence from nephrology and oncology settings, this review shows how material selection, surface engineering, and multifunctional coating strategies can improve hemocompatibility, limit microbial colonization, and enhance device durability. It also underscores a key translational challenge: many promising technologies remain uni-functional or insufficiently validated clinically. These insights provide a biomaterials-focused framework for the design of safer and longer-lasting vascular access devices.
1. Introduction
Central venous access devices (CVADs), including central venous catheters (CVCs), peripherally inserted central catheters (PICCs), and implantable ports (PORTs), are widely used across diverse clinical settings, as life-threatening conditions for patients in intensive care, parenteral nutrition, or long-term intravenous therapies.1,2 CVADs serve as key vascular access for patients with chronic kidney disease (CKD) and cancer, enabling effective delivery of hemodialysis and systemic anticancer therapy (SACT). CKD affects more than 800 million people globally,3 with prevalence increasing by more than 30% over the last three decades.4 New cases more than doubled between 1990 and 2019, reaching 18.99 million in 2019,5 while CKD-related deaths are projected to rise from 1.2 million in 2017 to over 1.8 million by 2030.6 In 2010, more than 2.6 million people with CKD progressed to end-stage renal disease (ESRD), undergoing dialysis or receiving a renal transplant, and this number is expected to reach 5.4 million by 2030.4,7 In nephrology, reliance on central vascular access has increased over the past decade: between 2018 and 2022, the proportion of patients initiating hemodialysis with a catheter rose by 3.9%, reaching 84.7% in 2022.8
Globally, cancer incidence is also rising. According to recent estimates by the International Agency for Research on Cancer (IARC) and the American Cancer Society (ACS), 20 million new cancer cases and 9.7 million deaths occurred in 2022,9 with projections suggesting approximately 35 million new cases and 18.5 million deaths annually by 2050.9,10 The number of patients requiring SACT as first-line therapy is expected to increase from 9.8 million in 2018 to 15 million annually by 2040.11 These trends highlight CKD and cancer populations as relevant case studies to examine the challenges and optimization strategies for CVAD use. While CVADs improve patient comfort, minimize repeated procedures, and support consistent treatment delivery, their use is frequently accompanied by adverse events (AEs) that can compromise outcomes. Due to direct and prolonged blood contact, they introduce significant risks that must be carefully considered, including thrombosis, infection, and hemolysis. These complications are influenced not only by procedural and patient-specific factors but critically by device design and material properties. Understanding how CVADs materials affect blood compatibility, thrombogenicity, and infection risk is crucial not only for preventing AEs, but also for optimizing therapy, improving patient outcomes, and guiding the development of safer vascular access technologies.12 This review focuses on recent advances in CVAD biomaterials, emphasizing surface modification strategies, durability, and multifunctional design aimed at mitigating device-related complications, with CKD and cancer used as case studies to demonstrate how targeted material selection and engineering can optimize device performance in high-risk populations, while also identifying current challenges, knowledge gaps, and opportunities for future innovation.
2. Landscape of vascular access in kidney failure and cancer CVADs: type of devices and uses
According to the CVAA Occlusion Management Guideline for Central Venous Access Devices (CVAA),13 there are four main types of CVADs: peripherally inserted central catheters (PICCs), non-tunnelled central venous catheters (CVCs), tunnelled CVCs, and implantable venous access devices, also known as PORTs, port-a-cath or totally implantable venous access ports (TIVAPs). CVADs are routinely used in patients with ESRD and cancer to perform hemodialysis and SACT, particularly when urgent dialysis is needed, or creation of a permanent access (arteriovenous fistula or graft) is not feasible due to comorbid conditions.14–16 While fistulas and grafts generally carry lower risks, they have important limitations, non-maturation, thrombosis, and infection, although these risks are lower than with catheters.17 Across all CVAD types, thrombosis and infections remain the most frequent complications.18 In nephrology, CVCs are the intervention used to initiate hemodialysis in approximately 80% of ESRD patients in the USA14 and nearly 60% in France,19 with similar trends reported in the United Kingdom (UK), where patients begin hemodialysis with either temporary (i.e., non-tunnelled) or tunnelled CVCs.20 The start of dialysis with the two types of hemodialysis catheters was evaluated using survey-based data from the International Society of Nephrology Global Kidney Health Atlas (ISN-GKHA), reflecting differences between regions across the world. For example, tunnelled catheters were frequently used to start dialysis in North America, whereas non-tunnelled catheters were more commonly used in Latin America and Africa.21 In oncology, PICCs and PORTs are the most commonly employed CVADs. Studies have documented the widespread use of PICCs, or PICC lines,22–25 which are often preferred for ease of insertion, management, and lower costs.26 However, TIVAPs offer significant advantages for intravenous SACT, supporting prolonged treatment while enhancing patients’ quality of life (QoL)27 and providing a safer and more comfortable access route compared to PICCs.28 Estimates indicate that by 2012, over 400.000 TIVAPs were implanted annually in the USA,29 with similarly high numbers reported in Germany.30 Since then, the use of PORTs has continued to grow globally, reflecting their clinical utility.31
Table 1 summarizes the different types of CVADs and their respective clinical uses. This overview sets the stage for discussing how device choice, materials, and surface engineering strategies can influence complications and optimize outcomes in high-risk populations.
Table 1. Central venous access devices: types and uses.
| Device type | Description | Duration of use | Applications |
|---|
| CVC | Tunneled | Catheter is inserted subcutaneously (tunneled) under the skin for a tract before exiting the skin | Prolonged access, long-term therapy | Drug administration, hemodialysis, nutritional support |
| Non tunneled | Catheter is inserted percutaneously via direct puncture and insertion into the vein | Temporary access, short-term therapy | Emergency dialysis (e.g., acute kidney injury) when immediate vascular access is required |
| PORT | Small self-sealing reservoir that is subcutaneously implanted under the skin and a tunneled connects the reservoir with central venous system through a deep vein of the chest | Prolonged, intermittent access, long-term therapy | Fluid or nutrition administration, drug administration (cancer treatment) |
| PICC | Catheter is inserted into a peripheral vein and advanced to the superior or inferior vena cava | Mid-term access, short- intermediate therapy | Nutrition administration, drug administration (cancer treatment) |
3. Challenges in kidney and cancer care: Device-related infections and thrombosis
All types of devices used in hemodialysis and oncology tunnelled and non-tunnelled CVCs, PORTs, and PICCs – are susceptible to device-related complications. Procedure-related events may occur shortly after hemodialysis catheter placement34 or surgical implantation of a venous port,35,36 and can include pneumothorax, embolism, arrhythmias, catheter misplacement, or dislodgement. Device-related infection and thrombosis remain the most common late and long-term complications associated with CVADs use, particularly in patients requiring CVCs and PORTs.32,34,37 These complications are tightly linked to the blood–device interface, where protein adsorption, biofilm formation, and endothelial trauma initiate inflammatory and coagulation pathways, creating a nidus for thrombosis and infection. Thus, the intrinsic interplay between blood components and catheter materials acts as a critical driver of both thrombogenicity and infective risk, particularly during prolonged indwelling times.38,39 These AEs are typically related to prolonged catheterization and correlate with increased morbidity and mortality risk.19 It should also be acknowledged that infections and thrombosis may occur with peripherally inserted devices, such as midlines, generally used for short dwelling time,40 or when surgical accesses like arteriovenous fistula or grafts are created.18,41
3.1 Local and bloodstream infections
Catheter-related infections (CRIs) can present as either local or bloodstream infections.37,42,43 Local infections typically occur at the catheter exit site, along the tunnel tract, or at the pocket/reservoir. Patients experiencing a local infection typically exhibit inflammatory signs such as erythema, warmth, and pus formation. As reported by Cobo-Sanchez et al, the incidence of exit site infections for hemodialysis catheters varies, partly due to inconsistent definitions in the literature. For tunnelled catheters, exit site infections range from 0.35 to 8.3/1,000 catheter-days, while for non-tunneled catheters they span from 8.2 to 16.75/1,000 catheter-days.44 In totally implanted PORTs, local infection signs are reported in only 7-12% of bloodstream infection cases.45
Catheter-related bloodstream infections (CRBSIs) are defined by the presence of clinical symptoms combined with at least one positive blood culture, in the absence of another identifiable infection source, alongside a matching positive culture at the catheter tip.19,46 Bloodstream infections are frequent in patients on haemodialysis47 and constitute a major concern for cancer patients with implanted port systems.37 Microorganisms can colonize indwelling catheters within 24 hours of insertion, forming biofilms on the catheter surface. These biofilms act as reservoirs for pathogens, which may subsequently enter the bloodstream, leading to infection. Common causative microorganisms include Staphylococcus aureus, coagulase-negative Staphylococcus, Enterococcus, Pseudomonas, or Candida.37,47–49 Infections spreading can cause severe complications such as infective endocarditis, septic arthritis, and septic shock,14,50 requiring catheter removal when antibiotic therapy is not effective.34,51 Reported infection rates for hemodialysis catheters and PORTs are highly variable. In hemodialysis patients, reviews indicate CRBSI rates between 0.6 and 6.5 per 1,000 catheter-days,14 and between 0.4 and 32.4 per 100 patients-months.47 One study reported up to 16.5% of patients developing CRBSIs within one year of catheter placement.34 Tunnelled hemodialysis catheters are consistently associated with lower infection rates than non-tunnelled devices: a 2006 systematic review reported device- related bloodstream infection rates of 1.6 per 1.000 intravenous device days for long-term, tunnelled, cuffed hemodialysis catheters, compared to 4.8 per 1.000 intravenous device days for temporary, non-cuffed catheters,52 and such a trend aligns with more recent studies.53 In oncology, infections associated with implanted ports range between 3 and 10%,54 consistent with global estimates.55,56 In Taiwan, a study of 586 ports in oncological population described a 5.6% infection rate and 0.15 infections per 1,000 device-days.57 An Indian retrospective study (2020 to 2023) registered 7.5% infections (9 out of 119 patients),58 while a pediatric oncology center in Saudi Arabia documented a lower infection rate of 3.13%, aligning with contemporary rates of 3–4%, markedly lower than earlier reports of up to 16%.59,60 A retrospective comparison of PORTs and PICCs in patients with solid or hematological tumors highlighted infection rates of 6.4% for ports (158 out of 2475 enrolled patients), and 11.9% for PICCs (106 out of 809 enrolled patients).61 As pointed out by Rieger et al, such findings were somewhat contrasting with other studies, such as the CAVA trial62 and the PICCPORT trial.63 The observed infection patterns emphasize the pivotal role of the blood–device interface, where rapid biofilm development and complex host–material interactions sustain pathogen reservoirs, driving CRIs and reinforcing the imperative for improved catheter materials and targeted preventive strategies.
3.2 Catheter-related thrombosis
Multiple processes contribute to the pathogenesis of thrombi associated with CVADs/catheters.64 Catheter placement can cause endothelial trauma, which, combined with increased catheter-induced blood flow, activates the coagulation cascade and promotes thrombus formation (blood clots), potentially leading to lumen occlusion.34 Thrombosis may occur within the catheter lumen (intraluminal), resulting in lumen obstruction, or around the catheter (mural), causing partial vein occlusion and increasing the consequent risk of deep vein thrombosis.65 Related complications include the formation of a fibrin sheath or sleeve along the catheter surface, where fibrotic material accumulates.36 Catheter-related thrombosis is typically defined as a mural thrombus extending from the catheter into the vessel lumen, as outlined in the CVAA13 and Gavecelt66 guidelines. It most commonly involves the deep venous system of the upper extremities, although other districts may be affected depending on the catheter placement.65 Thrombi migration to the right atrium or superior vena cava can result in serious complications, such as pulmonary embolism and superior vena cava syndrome.67 Despite its potential severity, catheter-related thrombosis is often asymptomatic, with only about 5% of cases presenting clinical symptoms, which can delay diagnosis. In hemodialysis patients, thrombotic events represent major complications, with highly variable incidence rates reported across studies.34 A recent review outlined that CVC thrombosis in hemodialysis patients ranges from 12% to as high as 52%, reflecting differences in study design, clinical settings, and patient-related risk factors.68 In cancer patients, symptomatic catheter-related thrombosis occurs in approximately 2–5% of PORTs, while overall thrombotic complications typically range between 5% and 13%.29,69 Earlier reports showed rates up to 28%, though advances in catheter materials and insertion techniques have reduced incidence to below 13% in recent years.29,69,70 Comparing PICCs and PORTs, Rieger et al revealed similar thrombosis rates (3.4% vs 3%),61 whereas other studies consistently find higher rates associated with PICCs. The CAVA trial reported venous thrombosis rates of 11% for PICCs versus 2% for ports,62 while the PICCPORT trial found rates of 8% versus 1% for deep vein thrombosis.63 Overall, the incidence of catheter-related thrombosis and bloodstream infections varies widely across devices and patient populations. Contributing factors include the investigated population (e.g. adults or pediatric), the stage and the type of disease (e.g. dialysis duration, hematological or solid tumors), the patient clinical history (e.g. comorbidities, body mass index), clinical center resources, infrastructures and adherence to aseptic procedures and care guidelines, as well as the specific design type of catheter or the anticipated period of use.71–73 These patterns highlight the central role of the blood–device interface in thrombus formation, where endothelial trauma, altered flow, and material–blood interactions converge to drive thrombogenicity, reinforcing the need for optimized catheter design and evidence-based preventive strategies.
4. Selection of devices for hemodialysis and cancer treatment: multiple factors guide the choice
The spectrum and frequency of device-related complications are influenced by patient characteristics, disease-specific considerations, device type, and duration of use. Understanding these factors is essential to optimize outcomes and minimize infection and thrombosis in high-risk populations.
4.1 Patient-related factors
Patient characteristics critically shape both device selection and the risk of catheter-related complications, particularly in high-risk populations such as patients with CKD/ESRD or cancer (
Table 2). These factors interact closely with the blood–device interface, where endothelial trauma, altered flow, and biofilm formation drive thrombogenicity and infection, as described in the preceding sections. Disease-induced alterations in coagulation and immune function further amplify susceptibility to both thrombosis and CRBSIs.74,75 Comorbidities are major determinants of risk. In ESRD, diabetes mellitus is frequently associated with higher CRI incidence.64,67,76,77 A history of prior CRI64,78 and nasal colonization with Staphylococcus aureus79 further elevates infection susceptibility. Advanced age and female sex are additional well-documented risk factors for CRBSIs in hemodialysis patients, while laboratory markers, including low serum haemoglobin and albumin levels, and elevated levels of procalcitonin and C-reactive protein (CRP), also correlate with increased complication rates.80 In hemodialysis, cardiovascular comorbidity, age, obesity, hypertension, and body mass index (BMI) influence the likelihood of catheter-related thrombosis.65,68,81 A study by Mohazzab et al76 investigated tunnelled hemodialysis catheters, and identified hypertensive, female and obese individuals as those with higher predisposition for catheter thrombosis. Notably, the development of an infective status in patients may represent a risk factor for catheter-related thrombosis, and the inflammation response triggered by infection can promote the development of the disorder.68
Table 2. Patient- and disease-related factors influencing catheter-associated infections and thrombosis, with reported complication rates.
| Patient population | Risk factors | Infection risk (CRBSI) | Thrombosis risk | Representative studies |
|---|
| ESRD patients on hemodialysis
| Diabetes mellitus, prior CRI, advanced age, female sex, low hemoglobin/albumin, elevated CRP/procalcitonin77,78,80 | • Moderate–High: 0.6–6.5/1,000 catheter-days; up to 16.5% within 1 year14 | • High: 12–52% (varies by study, comorbidities, catheter type)68 | 64,65,67,76–78,80,81 |
| Cancer patients undergoing SACT
| Immunosuppression, neutropenia, tumor type/location, histology, stage82 | • Moderate: 3–10% (PORTs), pediatric 3–4%,54 PORT vs PICC 6.4% vs 11.9%61 | • Moderate: 2–5% symptomatic PORTs, overall 5–13%; PICCs generally higher (CAVA, PICCPORT)29,62,63,69 | 36,82–84 |
In oncology, catheter-related thrombosis and infection are often driven by the prothrombotic and immunosuppressive nature of malignancy, while the immunocompromised state induced by both the disease and SACT further increases the risk of infection. Moreover, cancer patients exhibit higher risk of thrombosis,36 primarily due to a hypercoagulability status influenced by tumor biology, cancer treatment and tumor effects on procoagulant factors release, vascular endothelial cells and platelets.83 Specific anticancer drugs can influence the risk of thrombosis,84 while additional contributing factors include tumor type (solid tumor vs hematologic), tumor location, histology features, and disease stage of cancer.82 Patient-related variables such as age, lifestyle, body mass, and comorbid conditions further modulate the overall risk profile. These findings underscore the intricate interplay between patient-specific vulnerabilities, disease-driven alterations, and the blood–device interface in shaping thrombosis and infection outcomes. Integrating this knowledge into device choice, insertion protocols, and preventive care can markedly improve safety in vulnerable patients.
4.2 Catheter-related factors
Catheter-related factors broadly include device materials and design features, such as length, tip configuration, and number of lumens, as well as the placement technique and choice of access site (
Table 3). These factors play a critical role in catheter performance, durability, and risk of infection and thrombosis. In the following subsections, we examine how biomaterial composition, device design, and clinical context influence clinical outcomes in patients undergoing prolonged hemodialysis or chemotherapy.
Table 3. Catheter-related and procedure-related factors in hemodialysis and cancer treatment.
| Type of CVADs used in hemodialysis and SACT | Key considerations and impact |
|---|
| CVCs (Tunnelled/non tunneled) |
PORTs |
PICCs |
|---|
|
Material34 | Tunneled: silicone, polyurethane, carbothane (copolymer)
Non tunneled: silicone, polyurethane | Implantable port: titanium, polymers (Port bodies)
Silicone, polyurethane (catheter) | silicone, polyurethane |
|
| Catheter design (e.g. tip, lumen, diameter)14,32,85 |
▪ Tip shapes: symmetrical, step-tip, split-tip, Y-tip or self-centering (tunneled) ▪ Number of lumens: single, double, triple (tunneled/non tunneled) ▪ Catheter size diameter: 12-16 Fr (hemodialysis tunneled catheters)86
|
▪ Presence of valves: valved or open-ended catheters ▪ Number of lumens: single or double port ▪ Catheter size diameter:5-9 Fr
|
▪ Presence of valves: valved or open-ended catheters ▪ Number of lumens: single, double, triple ▪ Catheter size diameter:3-5 Fr
|
▪ Further studies on impact of tip design on device performance and functionality, to consider with other contributing factors ▪ No significant correlation to the presence of valves ▪ Multiple lumens may represent a risk factor for complications such as bloodstream infections ▪ Evaluation of catheter size and catheter-to-vein ratio for adequate blood flow, but avoid risk of thrombotic-related catheter occlusions
|
| Access/placement site14,33,87 |
▪ Insertion into internal jugular vein mainly, if not accessible use of femoral vein and lastly subclavian vein ▪ Right-side of internal jugular vein preferred to left-side ▪ Catheter tip positioning: into superior vena cava vs pericavoatrial junction or right atrium
|
▪ Insertion into peripheral veins – e.g. brachial, cephalic, balisic- and advanced to superior or inferior vena ▪ Right-side arm for catheter insertion
|
|
▪ Internal jugular vein as preferred access route associated to fewer infections, catheter dysfunction/device removal and number of catheterization ▪ Lateralization and preference for right-side insertion for fewer infection and dysfunction complications ▪ Evaluate catheter tip positioning
|
| Insertion procedure88,89 |
▪ Various placement methods (surgical procedures or not) ▪ Use of ultrasound guidance versus landmark anatomical procedures ▪ Clinical use of techniques fluoroscopy, ECG or radiography
|
▪ Education and training of clinical staff ▪ Key imaging support to guide insertion and minimize complications related to procedure such as pneumothorax, embolism
|
4.2.1 Biomaterial composition
Hemodialysis catheters are primarily made of polyurethane, silicone, or carbothane (a polyurethane/polycarbonate blend),90,91 while PICCs typically use silicone or polyurethane, with a tendency towards polyurethane due to its handling characteristics and performance.33,92 PORT reservoirs combine titanium, stainless steel, or polycarbonate with silicone or polyurethane catheters.69,93 Silicone’s softness and flexibility are favourable to minimize endothelial damage during insertion, but it can make the insertion procedure more challenging.34 Conversely, polyurethane is characterised by rigidity during insertion, facilitating the placement, but it softens at body temperature. Carbothane, a polyurethane/polycarbonate copolymer, combines strength and softness to enhance durability and flexibility.94 Polyurethane and carbothane are frequently used for hemodialysis catheters,90 especially for tunnelled long-term use catheters.94 Recent evidence highlights the increasing utilization of hemodialysis catheters, associated complications, and the role of optimized catheter designs and functional coatings in reducing adverse outcomes and improving patient management.95 Although studies have not conclusively established a link between silicone and increased infection risk,90,96 one investigation on tunnelled hemodialysis catheters reported a higher incidence of kinking in silicone-based catheters compared to those made of polyurethane.91 In cancer patients, prevention of catheter-related bloodstream infections remains a priority: systematic reviews have assessed non-drug interventions, including coated CVCs, highlighting limited but promising evidence for efficacy in hematological malignancy patients.97 Similarly, recent reviews summarize strategies to prevent catheter-related infections, emphasizing antimicrobial-coated catheters and insertion/maintenance bundles.98 Cochrane studies have examined the impact of different materials and designs on PICC-related complications, highlighting the need for additional high-quality trials to strengthen the evidence and guide clinical decision-making.92,99 In cancer patients using implantable venous-access ports, some studies have found that silicone catheters are more prone to mechanical instability and breakdowns, while polyurethane catheters are more frequently associated to infections and thrombotic complications.100–102 In paediatric oncology, studies evaluating long-term venous port use have suggested that polyurethane catheters may be more susceptible to breakage and can be more difficult to remove.103,104
4.2.2 Device design features
Catheter architecture can differ by its manufacturing design, including catheter tip shape, lumen number, and diameter size. The type and design of catheters usually depend on clinicians’ choice, as reported in the current 2019 Kidney Disease Outcomes Quality Initiative guidelines on vascular access.46 Tunnelled catheters used for long-lasting hemodialysis in patients with ESRD are typically cuffed, with a polyester cuff (i.e. Dacron) that promotes growth of tissue around it, prevents catheter displacement, and potentially reduces infection risk.14,34,105 Over the years, different types of shapes have been developed for the tip of hemodialysis catheters,34,105 particularly to prevent backflow.96 Common tip configurations—referring to the distal end of the catheter placed within the bloodstream—include symmetrical, step-tip, split-tip, Y-tip, and self-centering.34,105 Recent studies have investigated interactions between catheter materials and vessel walls, highlighting the importance of mechanical and surface considerations to reduce thrombosis and endothelial damage: interactions between catheter surfaces and vascular tissue can induce localized stress and protein adhesion, which are mitigated by hydrophilic or anti-adhesive coatings.106 Hydrophilic-coated intermittent catheters (HCICs) have been shown to improve QoL, reduce urinary tract infections, and may be cost-effective compared with uncoated catheters.107 An Australian cohort study by Lazarus et al.108 evaluated tunnelled hemodialysis catheter performance, focusing on tip design and blood flow adequacy.109 Step-tip catheters showed shorter functional lifespans compared to symmetrical tips, while split-tip catheters performed well, albeit in limited numbers.108 Overall, as noted by Prasad & Vachharajani,109 catheter tip design influences dysfunction and performance, but further studies are needed to clarify additional contributing factors. Valved catheters, with a closed tip to prevent blood reflux and allow heparin flushing,32 and not valved/open-end catheters,110 show similar complication profiles. Early and later studies indicate no significant differences in infection, thrombosis, or catheter removal between valved and non-valved central venous ports,111,112 and comparable findings have been reported for PICCs in cancer patients.86 Conversely, it has been demonstrated that PICCs with proximal valves were associated with a higher incidence of unplanned removal compared to open-ended devices, a difference particularly marked in patients without malignancy.113 Other key design features include the diameter size and the number of lumens. CVADs are available in a wide variety of sizes, typically measured using the French (Fr) scale. As summarised by Kehagias et al,32 Hickman (tunneled) catheters usually range from 7 to 9 Fr, PICCs from 3 to 6 Fr, and IPs from 5 to 9 Fr. Hemodialysis tunneled catheters are generally larger, with external diameters ranging from 12 to 16 Fr.14,85 Diameter size is a critical factor in ensuring adequate blood flow85 and must be taken into consideration within the catheter caliber-to-vein ratio.64 Indeed, catheter size can affect the development of catheter-related thrombotic occlusions, as observed in TIVAD used in breast cancer patients.114 CVADs are available in various lumen configurations: single, double, and triple lumens are used in tunnelled catheters and PICCs, whereas implantable venous access systems can have a single or double port.13 Multi-lumen designs can contribute to optimizing blood flow during dialysis and allow simultaneous administrations; however, they may also increase the risk of complications such as catheter-related bloodstream infections, as highlighted in a recent meta-analysis.115 Specifically, for CVCs, multiple lumens may slightly increase the risk of infections.116 In hemodialysis patients, no differences in complications due to the presence of multiple lumens are known,117 while in cancer patients, double-ports have been observed to be associated with an increased risk of complications such as bloodstream infections118 and catheter malfunction or related thrombosis.119 Overall, the 2024 Infusion Therapy Standards of Practice recommend, for general patients, an optimal assessment of catheter-to-vein ratio, and the use of the smallest catheter diameter and the fewest number of lumens during infusion therapy.120
4.2.3 Clinical context and biomaterial performance
While patient-specific factors shape the baseline risk for complications, biomaterial properties and catheter design determine how these risks translate into clinical outcomes, particularly in prolonged hemodialysis or chemotherapy. Biomaterial and design choices must align with patient condition and therapy type. In prolonged hemodialysis, durability, thrombotic resistance, and flow optimization are critical, whereas in chemotherapy, device stability, infection resistance, and compatibility with cytotoxic drugs are critical.91,100–104,121 The blood–device interface, governed by material surface properties, protein adsorption, and flow dynamics, dictates thrombogenic and infective potential.34,115–120,122 Integrating patient-specific risk factors, careful insertion, maintenance, and monitoring enables clinicians to maximize CVADs performance, minimize complications, and optimize treatment outcomes. Specifically, material and design considerations should be tailored to the clinical context: ensuring durability and thrombotic resistance in prolonged hemodialysis, while prioritizing stability, infection prevention, and drug compatibility in oncology patients. While biomaterial properties and catheter design establish baseline performance and influence thrombosis and infection risk, the overall success of CVADs use in high-risk populations also critically depends on procedural factors.
4.3 Procedure-related factors
Procedure-related factors play a pivotal role in the performance of CVADs and in the risk of associated complications (
Table 3). Numerous studies highlight that both the choice of access vein and the final catheter tip position significantly influence device performance and safety.87,123 Non-Tunneled Central Venous Catheters (NTCVCs), typically used for short-term (<14 days) and urgent hemodialysis, are most commonly inserted percutaneously via the right internal jugular vein (IJV), with the terminal catheter tip reaching the superior vena cava.14,33 Tunneled Central Venous Catheters (TCVCs), employed for long-term vascular access and ongoing haemodialysis, also rely on the IJV as the preferred entry site.14 PICCs are introduced through peripheral veins, such as the basilic, brachial, or cephalic vein, finally reaching the superior or inferior vena cava.32,33 PORTs consist of a surgically placed reservoir, typically located in a tissue pocket in the arm or chest of patients, and a catheter, connected to the port, usually advanced until the superior or inferior vena cava.33 The choice of access route is a critical step, since the access type may correlate with complication risks.124 For instance, in NTCVCs, the skin exit site lies in proximity to the venous entry point, and this position can heighten the risk of catheter-related infections. In contrast, the tunnelling procedure, which involves the subcutaneous passage of the catheter beneath the skin, can be a challenging phase for clinicians91; however, by creating spatial separation between the skin entry site and the venous insertion point, it significantly reduces the risk of infection.33 When the jugular vein is unavailable in hemodialysis patients, due to occlusions or other catheterizations, alternative access sites such as the femoral or subclavian veins might be considered. Nevertheless, these routes are often associated with higher complication risks, as reported by Sohail et al.14 The lateralization represents another factor in clinical decision-making: the right side of the IJV is often recognised as preferable access,14 and left-sided access has been linked to increased infection, catheter dysfunction, and need for repeat catheterizations in hemodialysis patients.87,125,126 Similar findings have been reported in oncology, where right-sided PORT insertion showed lower rates of both early and late complications,127 and right-arm PICC placement was associated with fewer AEs.128 Following insertion, a crucial factor is the optimal position of the catheter tip within the vascular system, with current evidence supporting placement into the superior vena cava,129,130 compared to other options as the pericavoatrial junction or right atrium. However, case studies point out contrasting findings, suggesting the necessity of a case-by-case evaluation of vein accessibility. CVAD placement techniques range from minimally invasive procedures under local anesthesia to complex surgical interventions requiring specialized personnel and equipment.33,131,132 Procedural success is contingent on clinician expertise, training, and access to appropriate technological support, to avoid repeated venepuncture attempts or risk complications such as pneumothorax, embolism, arterial puncture, or hematoma. The introduction of ultrasound guidance into clinical practice has significantly improved placement outcomes, and it is now recommended by major vascular access guidelines.33,88 A Cochrane systematic review demonstrated that 2D ultrasound guidance increases placement success rate and reduces hematoma formation compared with anatomical landmark techniques.133 Beyond facilitating catheter insertion, ultrasound is also valuable for pre-procedural assessment of vascular access in hemodialysis patients88 and in the placement of totally implantable venous ports.89 Clinical practice is oriented to further advancements in placement procedures techniques and to increase the success rate of CVADs placement, with literature also highlighting the role of fluoroscopic, radiological, and electrographic guidance methods.134–136
5. Surface modification strategies to improve CVADs use in kidney and cancer care
Materials engineering and surface modification are pivotal to ensuring the safe and effective use of CVADs in high-risk populations. Surface modifications are broadly classified as passive or active, employing physical, chemical, or combined approaches to impart antimicrobial/antibacterial, anti-thrombogenic, anti-fouling, and anti-adhesive properties, thereby minimizing device-related infections and thrombotic complications.137–139
5.1 Functional goals of surface modification in CVADs
Blood-contacting surfaces of CVADs rapidly interact with proteins and cells, triggering thrombotic cascades, clot formation, and providing a substrate for bacterial adhesion and biofilm formation.137 Optimally engineered surfaces must therefore be biocompatible, hemocompatible, durable, safe, and functionally optimized. Key surface characteristics, including wettability, charge, roughness, and chemical composition, strongly influence protein adsorption, cellular interactions, bacterial adhesion, and bio- and hemocompatibility, directly affecting the risk of device-related infections.140
5.2 Surface-engineering strategies: the biomaterials toolbox against complications
From a biomaterials engineering perspective, CVAD surface modifications can be organized into complementary strategies that address the mechanistic pathways leading to infection, thrombosis, and device failure. Together, these surface-engineering approaches constitute a biomaterials toolbox to mitigate CVAD-related complications. These modifications yield direct clinical outcomes in hemodialysis and oncology, such as reduced heparin needs and prolonged patency in hemodialysis trials, and lower CRBSI in cancer cohorts.141
Table 4 summarizes the main surface modification strategies investigated for CVADs, highlighting their key features, intended functional goals, and the principal limitations associated with each approach.
Table 4. Overview of main types of surface modification strategies.
|
Type of surface modification | Features | Main concerns |
|---|
| Antiseptics impregnation/coatings142,143 |
|
|
| Silver-based144–146 |
|
|
| Heparin-bonded coatings90,147,148 |
|
|
| Hydrophilic polymers137,149,150 |
• Studies on use PEG, zwitterionic polymers • Anti adhesive/adsorption properties, to prevent fouling and thrombosis
|
|
| Surface pattern modifications137,151 |
• Studies on micro, nanopatterning, bioinspired surface changes • Mimicking natural surface properties against bacterial colonization and platelet adhesion
|
|
| NO-releasing surfaces152 |
|
|
| SLIPS137,149 |
• Introduction of liquid on surface porous material
Potential anti-thrombosis and anti-infection, with self-cleaning properties
|
|
Passive Physicochemical Modifications- tuning surface properties such as wettability, roughness, charge, or elemental composition to influence protein adsorption, cellular interactions, bacterial adhesion, and hemocompatibility.137,140 Recent studies on fluorinated polyphosphazene coatings have demonstrated improved mechanical stability while maintaining antithrombogenic performance, making them promising passive surface modifications for CVCs.153 In oncology, hydrophilic and PEG-based surface modifications have been investigated to reduce catheter occlusion and improve short-term patency, although robust clinical evidence in CVAD-specific settings is still emerging.154
Covalent Immobilization of Biomolecules or Polymers– permanent attachment of functional agents to confer biofunctional properties such as anticoagulation or antifouling behavior.149,155 Bioinspired zwitterionic NO-generating coatings have been shown to provide long-term antimicrobial and antithrombogenic activity through covalent attachment of functional polymers and catalytic components on CVC surfaces.156 Similarly, chitosan-based coatings have demonstrated biocompatible and bactericidal properties when immobilized on catheter surfaces, representing a “green” biofunctional approach.157 Additionally, dual-functional coatings integrating lysine and Cu2+ with zwitterionic polymers have shown both antibacterial and antithrombotic effects, providing a multifunctional covalent approach for improving long-term CVC performance.158 Clinically, covalent immobilization strategies such as heparinized surfaces have demonstrated improved hemocompatibility in hemodialysis applications by reducing protein adsorption, platelet adhesion, and clot formation. Advances in plasma activation, polymer grafting, and nanotechnology enhance coating stability, although long-term clinical validation remains limited.159
Drug- and Ion-Releasing Coatings– controlled local release of antimicrobial or antithrombotic agents, including antibiotics (e.g., minocycline/rifampin) and silver-based coatings. These strategies address infection prevention and thrombosis. Polymer-drug coatings specifically designed to reduce thrombogenicity and improve hemocompatibility represent an advanced approach to locally deliver antithrombotic agents while preserving systemic safety.160 In addition, phyto-assisted ZnO nanoparticles provide non-antibiotic antibiofilm activity via slow ion release, representing a promising drug-free antimicrobial strategy.161 In clinical studies, surfaces engineered to release drugs or ions have demonstrated improved hemocompatibility and reduced thrombogenicity in hemodialysis-related applications; although these results come from stent-based devices, they highlight the potential of similar surface chemistries for CVADs.162
Topographical and Nano-Structured Surfaces – micro- and nanoscale features (e.g., micropatterning, SLIPS, nitric oxide-releasing surfaces) that modulate bacterial adhesion, platelet activation, and host–material interactions.137,149,152–163 Water-infused surface protection (WISP) has been proposed to prevent fibrin sheath formation by creating a dynamic blood-free interface, representing an innovative surface-driven approach to reduce thrombosis and biofilm-related failures.164 Clinically, pilot RCTs (CASCADE, 2025), testing CVAD securement and dressing strategies including sutureless devices and tissue adhesive, demonstrate feasibility and reduced device failure, highlighting how interface optimization complements surface-engineering approaches.165
5.3 Antimicrobial surface strategies
Antimicrobial surface modifications leverage antibiotics (e.g. minocycline/rifampin), antiseptics (e.g. chlorhexidine), and other metal ions (e.g., silver) to inhibit microbial colonization and biofilm formation. Commercially available catheters include chlorhexidine/silver sulfadiazine-coated devices (C-SS) (e.g., Arrowg+ard® Blue Plus CVC, Teleflex), and antibiotic-impregnated catheters with minocycline/rifampin (Spectrum®, Cook Medical). According to CDC’s 2011 guidelines, these strategies have proven efficacy against CRBSIs in multiple clinical settings166:
• Minocycline/rifampin-impregnated CVADs reduce infection rates in hemodialysis142 and cancer patients.143
• First-generation chlorhexidine/silver sulfadiazine–coated catheters (CHSS) reduce CRBSIs compared to non-coated devices167,168; CHSS may provide better protection against central line–associated bloodstream infections (CLABSIs) than silver iontophoretic (SI) catheters.169
• Second-generation CHSS catheters show reduced colonization, but randomized controlled trials (RCTs) were underpowered to show significant CRBSI reduction.170–173
• Systematic reviews and meta-analyses support antiseptic/antibiotic coatings as generally more effective than standard catheters174; however, inconsistencies exist for hemodialysis catheters.171
A Cochrane review further concluded that impregnated catheters reduce CRBSI and colonization, particularly for critically patients in intensive care, though benefits may not extend to all care settings.138 CDC’s 2011 and DGHO/AGIHO 2020 guidelines note that the higher cost and risk of microbial resistance should be considered, with priority given to high-risk patients or situations where standard preventive measures, such as strict adherence to antiseptic skin protocols, have failed.166,175 Owing to silver’s biocidal properties, catheters have been developed using silver-impregnated materials or compounds, including silver nanoparticles.144 Silver-based approaches are being explored across various clinical settings, including hemodialysis.144,176 Temporary hemodialysis catheters coated with silver nanoparticles demonstrate antibacterial activity without cytotoxic effects, though higher concentrations may induce bacterial activity and cytotoxicity.145,177 Clinical evidence is controversial: some studies show reduced catheter- and port-related infections, while others report no significant benefit. No significant reduction of infection was observed in a retrospective study evaluating silver-coated and uncoated catheters in hemodialysis and apheresis.178 Similarly, a meta-analysis observed that silver-impregnated CVCs did not correlate with lower rates of catheter-related bloodstream infections.179 Overall, silver-based surface modifications are emphasized due to their broad-spectrum antimicrobial activity, clinical evidence, and increasing use in vascular access devices. Consistent with this, silver-coated central venous catheters and silver-mixed ports have been shown to reduce catheter- and port-related infections, supporting both the clinical effectiveness and the growing focus on silver-based surface strategies.56,174 Additional biofunctional coatings, including enzymatic surfaces, have shown promise in preclinical studies. Surface-bound enzymatic coatings have demonstrated in vivo efficacy against Pseudomonas biofilms, providing a drug-free antibiofilm strategy,180 while chlorhexidine-silver coatings, although widely used, exhibit limited long-term efficacy and underscore the need for alternative topographical or chemical modifications.181 These innovations highlight the ongoing exploration of multifunctional antimicrobial strategies beyond conventional drug or silver-based coatings. Challenges remain in long-term use of silver-based and other antimicrobial coatings, including risk of promoting antibiotic resistance, potential loss of antimicrobial efficacy over time, limitations in coating durability and retention of active agents, and the need for more data on biocompatibility and inflammatory responses, particularly for patients requiring prolonged catheter use, such as those on dialysis or receiving chemotherapy.182
5.4 Approaches for anti-thrombogenic surface modifications
In addition to infection prevention, strategies against the development of device-related thrombosis are under investigation.183 Heparin-bonded catheters, featuring covalently attached heparin, inhibit thrombin formation and clotting, and may reduce biofilm nidus.90 A clinical study showed that heparin-coated tunnelled dialysis catheters maintain similar patency to standard catheters, resulting in significantly fewer catheter-related bacterial infections.147 Commercially available products include i) Palindrome precision H (heparin bonded, Mozarc Medical), ii) BioFloDuraMax (with proprietary technology, Angiodynamics), indicated to prevent blood clotting and for use in hemodialysis; iii) Palindrome™ Precision SI Chronic Catheter (Silver Ion, Mozarc Medical), combining heparin coating with a silver ion subcutaneous sleeve for hemodialysis. Heparin use carries risks, including bleeding, allergic reactions, and thrombocytopenia. Innovative dual-function coating combining heparin sodium with organosilicon quaternary ammonium surfactant has demonstrated in vitro and in vivo stability under extreme conditions, 60% thrombus adhesion reduction, and >97% broad-spectrum antibacterial activity.148 However, other studies found no significant difference in infection or mechanical complication rates between heparin-coated and uncoated catheters.184 Literature reflects variability in heparin coatings efficacy,149 highlighting the need for further studies across clinical settings and patient groups.138,185 Passive anti-thrombogenic strategies also employ hydrophilic and antifouling materials, such as hydrogels or hydrophilic polymers, like polyethylene glycol (PEG) and zwitterionic polymers, that prevent protein and cell adsorption, reducing catheter thrombogenicity.137,149 As reviewed by Balikci et al,176 there are studies exploring the use of PEG coating in hemodialysis catheters155 and totally implantable venous port systems.150 However, clinical data on long-term efficacy of these anti-thrombogenic coatings in CVADs remain limited, particularly in high-risk populations. Key concerns surrounding these approaches involve their long-term durability, particularly due to the potential for desorption, hydrolysis and oxidation.149
5.5 Novel approaches for surface modifications
Micropatterning modifies the surface topography to inhibit bacterial adhesion without the use of pharmacological agents. Inspired by natural surfaces such as shark skin and lotus leaves,137 these microtextures have been shown to reduce both bacterial colonization and platelet adhesion, as demonstrated in shark-skin-inspired micropattern CVCs.151 Micropatterning approaches suggest promising implications for the prevention of CRIs and thrombosis without drug-eluting agents. Further research is needed to optimize the manufacturing process, assess compatibility across various catheter types, and ensure comprehensive safety and efficacy in clinical use. Additional strategies include the use of nitric oxide (NO)-releasing materials and antimicrobial peptides, or Slippery Liquid-Infused Porous Surfaces (SLIPS). NO-based approaches exploit its properties as an antimicrobial agent and inhibitor of platelet aggregation, by mimicking the physiological release of NO from vascular endothelium.149 Experimental studies are oriented to identify NO-releasing donors that could be effective in the long term, and there are examples of investigations on charging catheter surfaces.152 SLIPS are based on creating porous surfaces able to hold introduced liquids with specific properties,137 and research is advancing through studies on slippery liquid-infused fluoropolymer in commercial central venous devices, such as PICCs, with potential antithrombogenic and infection-resistant properties.163 Ongoing research is increasingly focused on developing more effective technologies and solutions to prevent catheter-related bloodstream infections and thrombosis, both individually and in combination, given their mechanistic interplay and frequent clinical co-occurrence. Collectively, these approaches highlight the breadth of surface-engineering strategies under investigation.
Table 4 summarizes those that have reached a sufficient level of technological maturity for clinical consideration, together with their key features and main limitations.
6. Optimizing central venous access in kidney and cancer care: Best practices and the role of surface-modified devices
Several clinical guidelines address the use of CVADs in hemodialysis and oncology, with shared goals of minimizing infectious and thrombotic complications, preserving vascular access, and ensuring continuity of care (
Table 5). Proper device management throughout the lifecycle, combined with adherence to recommended protocols, improves clinical outcomes, maintains vascular access, and reduces mortality. Additionally, preventing complications can significantly lower healthcare costs associated with therapies such as hemodialysis and SACT.
Table 5. Clinical guidance practices for CVADs management.
| Applications |
Title | Provider | Year |
Main indications |
Reference |
|---|
| Hemodialysis | KDOQI vascular access guidelines | KDOQI | 2019 |
• ESKD Life-Plan supports an individualized approach to vascular access choice and location; Indications for use of hemodialysis CVC • CVC Care to Prevent Infection: aseptic measures and hygiene, flushing protocols e.g. 0.9% normal saline
| (Lok et al., 2020)46 |
| Spanish Clinical Guidelines on Vascular Access for Haemodialysis | GEMAV | 2017 |
• Recommended a non-tunnelled CVC in situations in which the catheter has to remain in place for under two weeks. For longer periods tunnelled CVC can be used • No specific tunnelled CVC model is preferred over others for haemodialysis. • CVC handling have to be performed under strict aseptic conditions • Assess the CVC exit site dressing at each haemodialysis session. Change it if wet, stained, detached or presents signs of infection; otherwise, change weekly. • Initial treatment of thrombosed or dysfunctional tunnelled CVCs should include vigorous saline flushing, guidewire-based mechanical intervention, or intraluminal fibrinolytic infusion; systemic fibrinolytics or catheter replacement. • Between haemodialysis sessions, tunnelled CVCs should be locked with heparin, citrate, or tPA, alternating with heparin as needed. • Catheter-related infections: routine antibiotic prophylaxis is not recommended before insertion or handling of CVC • Catheter-related infections: infection-treatment protocol after assessment of complicated/uncomplicated infections. Immediate withdrawal e.g. non tunnelled catheters, signs of septic shock
| (Ibeas et al., 2019)186 |
| Editor's Choice - Vascular Access: 2018 Clinical Practice Guidelines of the ESVS | ESVS | 2018 |
• Tunnelled cuffed CVCs as a long standing haemodialysis modality should be considered when the creation of arteriovenous fistulas or grafts is impossible or in patients with limited life expectancy. • Skin preparation for insertion of all type of access/cannulization • All vascular access late infections should be treated with antibiotics to cover both gram positive and gram negative organisms.
| (ESVS Guidelines) (Schmidli et al., 2018)187 |
| Guidelines for the Prevention of Intravascular Catheter-Related Infections | CDC | 2011 |
• Avoid the subclavian site in hemodialysis patients and patients with advanced kidney disease, to escape subclavian vein stenosis • Antibiotic/Antiseptic Ointments: apply at the catheter exit site after insertion and post-dialysis only if compatible with catheter material per manufacturer guidelines. • Antibiotic Lock/Flux Prophylaxis: use in long-term catheter patients with recurrent CRBSIs despite strict aseptic practices. • Anticoagulants: do not routinely use anticoagulant therapy to reduce the risk of catheter-related infection in general patient populations
| (Guidelines for the Prevention of Intravascular Catheter-Related Infections, 2011)166 |
| Hemodialysis clinical practice guidelines | CSN | 2006 |
• Catheter position should be confirmed using radiography, and the catheter tip should be readjusted as necessary to ensure proper position. • Change catheter exit site dressings at each hemodialysis treatment (Grade D, opinion) • Treat dysfunctional tunneled hemodialysis catheters with instillation/infusion of tPA using a protocol (Grade D, opinion) • Treat central venous catheter-related bacteremia with systemic antibiotics and catheter exchange over a wire (Grade D) • Treat catheter tunnel infections without bacteremia with parenteral antibiotics and appropriate local measures. • Catheter removal is indicated if the infection fails to respond to 2 wk of therapy.
| (Culleton, 2006)188 |
| Cancer | International experts consensus on optimal central vascular access device selection and management for patients with cancer | Panel of oncologists and healthcare professionals | 2024 |
• Totally implantable ports are preferred for infrequent long-term vascular access (>3–4 months duration, access every 2–3 weeks) • Patient lifestyle patients assessment and use of ports • Equipment for port placement and healthcare staff specialised in venous access procedures • Ports should be flushed at intervals ranging from 4 to 12 weeks according to specific local protocol • For all types of CVADs, use of ultrasound guided venipuncture for lower attempts and minimized risk (mechanical, thrombotic, and infectious complications)
| (Jahanzeb et al., 2024)189 |
| Clinical practice guidelines for breast cancer implantable intravenous infusion ports: Chinese Society of Breast Surgery practice guidelines 2021 | CSBrS | 2021 |
| (Ma et al., 2021)190 |
| Central venous access in oncology: ESMO clinical practice guidelines. | ESMO | 2015 |
• Attention to the placement of tip of the central venous catheter • Antimicrobial prophylaxis is not recommended as well as extensive routine prophylaxis with anticoagulants, or thrombolytic agents • No strong recommendation for use of antibiotic coated catheters, except than in clinical settings with high rates of bloodstream infections • Recommended neutral pressure mechanical valve connectors against risk of infections • Routine replacement of central venous catheters is not a preventive measure against infections • Routine maintenance and flushing protocols to prevent occlusions and aseptic practice (skin preparation) as Infection prevention strategies. • Implementation of bundle strategies including procedural guidelines for hygiene, dressing changes, and access as well as specific timeframes • Education and training of health care personnel, education of patients
| (Sousa et al., 2015)43 |
| Central venous catheter–related infections in hematology and oncology: 2020 updated guidelines on diagnosis, management, and prevention by the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO) | AGIHO of DGHO | 2020 |
• Infection Prevention: ensure strict hygiene and aseptic technique during catheter insertion and handling. Use chlorhexidine-based antiseptics, antimicrobial dressings (preferably transparent gel types), and consider antimicrobial-impregnated CVCs for long-term use if high CRI rates persist despite training efforts. • Implement education programs and bundles for nurses and physicians including continuous surveillance and feedback to reduce the incidence of CRIs
| (Böll et al., 2021)175 |
6.1 Device selection and clinical considerations
A primary focus of guidance documents is device selection, which requires careful assessment of patient- and catheter-related factors. Clinicians can rely on tools such as checklists, algorithms, and stepwise protocols to guide decision-making.33 Selection depends on clinical urgency,46 healthcare setting,189 and expected type of therapy and duration, as for non-tunneled versus tunneled hemodialysis catheters.14 Fully implantable venous ports are preferred to allow long-term, intermittent vascular access (>3–4 months duration, access every 2–3 weeks).189 Although catheter material and design (e.g. polyurethane versus silicone) have been widely studied, there is currently no consensus regarding their influence on infection or thrombosis risk.191,192 For instance, the Spanish Multidisciplinary Group on Vascular Access reported insufficient evidence to recommend any preferable catheter material.186 Device placement is equally critical: insertion site selection (e.g., internal jugular, subclavian, femoral veins) should consider patient anatomy, therapy duration, and clinical context, with the tip positioning ideally at the junction of the superior vena cava and right atrium to minimize arrhythmias and thrombosis.190 Imaging guidance, including ultrasound or fluoroscopy, is broadly recommended for all CVADs placements.43,46,189 Kidney Foundation guidelines46 suggest vascular access via arteriovenous fistulas and grafts over hemodialysis- central vascular catheters, due to a lower risk of catheter-related bloodstream infections.14,34,42 Nonetheless, CVCs remain common, as highlighted from an Italian study reporting a 61.8% prevalence among dialysis patients.193 In oncology, fully implantable catheters are recognised as associated with a lower risk of infections, as emerged from ESMO Clinical Practice Guidelines.43 A meta-analysis comparing PICCs with PORTs found PORTs to be safe and effective vascular access for SACT26; however, PICCs remain widely used due to their lower cost and ease of placement.
Following placement, maintenance and prophylactic care of CVADs are essential to prevent complications.194 Strategies include strict hand hygiene, maximal sterile barriers, and adherence to aseptic techniques such as the Aseptic Non-Touch Technique.195 Additional measures involve skin antisepsis with agents as 2% chlorhexidine, alcohol solutions, catheter hub decontamination, and the use of sterile dressings for exit sites and catheter securement.14,33,43 Regular flushing with 0.9% saline is recommended to maintain CVAD patency and prevent fibrin-related occlusion. Flushing intervals vary by device type and usage: while tunneled catheters and PICCs typically require weekly flushing when not in use, PORTs may only need flushing every four weeks or longer.43,46 Locking solutions, instilled into the catheter lumen and including anticoagulants, thrombolytics, or antibiotic/antiseptics, are applied based on patient risk and device type.46 Prophylactic use of antimicrobials is not recommended in cancer43 or hemodialysis patients,14,46 primarily due to concerns over antimicrobial resistance. Use of antimicrobial locks is generally reserved for patients with recurrent catheter-related bloodstream infections. Recent advances include the 2024 approval of a novel lock solution combining an antimicrobial agent and coagulant -taurolidine-heparin (Defencath), designed to reduce infection risk in hemodialysis patients with central venous catheters.196 The prophylaxis to prevent catheter-related thrombosis remains crucial. In cancer patients, anticoagulants prophylaxis is not routinely recommended as a standard approach, but is subject to case-by-case evaluation.43 A Cochrane review assessing anticoagulant agents such as unfractionated heparin, low-molecular-weight heparin, and vitamin K antagonists emphasized the need to balance thromboembolic risk reduction against potential AEs.197 Similarly, in the Kidney Disease Foundation guidelines, there is strong advice against routine use of prophylactic systemic anticoagulants for maintaining or improving patency of tunnelled hemodialysis catheters, considering limited evidence in support of to benefit and potential side effects.46 Intermittent heparin flushing is common practice, but evidence comparing it to saline is inconclusive. A Cochrane review by López-Briz et al. found no clear difference in occlusion prevention between heparin and 0.9% saline locking.198 Advances include the FDA-approved taurolidine-heparin lock solution Defencath, shown to significantly reduce catheter-related bloodstream infections in hemodialysis patients compared to heparin alone, though risks such as heparin-induced thrombocytopenia and sensitivity reactions must be considered.199,200 Use of thrombolytic-based prophylaxis with agents such as urokinase, streptokinase, and alteplase is also not routinely recommended in cancer care.43 However, selective use, such as weekly thrombolytic agent (recombinant TPA) locks in high-infection-rate units, is supported in nephrology guidelines.46
6.2 Implementation strategies and multidisciplinary care
Guidelines are most effective when combined with structured implementation strategies. Evidence shows that multidisciplinary teams, standardized care bundles, and continuous performance feedback are key to improving outcomes and ensuring safe vascular access management.46 Effective teams often include nephrologists or oncologists, nurses, pharmacists, vascular access specialists, and infection-prevention experts, enabling shared decision-making and timely interventions. Education is a key pillar: structured programs for healthcare providers, patients, and caregivers improve safe CVAD use and early recognition of complications.43,46 Although guidelines can provide a useful framework for clinicians when using CVADs, their implementation can be challenging and not straightforward. Patient-specific conditions, clinical judgement, cost considerations, clinical ease of management, resource availability, and staff expertise are factors that can limit the guidelines' implementation. Effective implementation of best practices for central CVAD management requires a coordinated, system-level approach. Evidence shows that multidisciplinary teams, the adoption of standardized care bundles, and continuous performance feedback are associated with reduced complication rates and improved patient outcomes. Beyond nursing and medical staff, the involvement of pharmacists, infectious disease specialists, infection-prevention teams, and vascular access experts ensures rigorous monitoring and timely, shared decision-making.201 Education remains a fundamental pillar of implementation strategies. Both nephrology and oncology guidelines emphasize the need for structured educational programs targeting not only healthcare professionals but also patients and families, intending to promote safe and informed CVAD use. Despite the benefits of guidelines as a framework for clinical decision-making, translating recommendations into daily practice remains challenging. Patient-specific conditions, clinical judgment, cost considerations, availability of technology and supplies, and varying levels of staff expertise can influence and sometimes limit the application of recommended practices. Organizational barriers, such as high workload, staff turnover, and differences in local care models, may further hinder full adoption. Consequently, many institutions have implemented phased or adaptive strategies, incorporating strong clinical leadership, ongoing quality-indicator monitoring, and continuous review cycles to tailor guideline implementation to the needs and constraints of the local context.202 Within this framework, surface-modified CVADs offer a strategic advantage for high-risk populations. By reducing thrombosis and infection risk, these devices complement guideline-based care and support improved vascular access outcomes. While surface-engineered catheters often involve higher initial costs, potential long-term savings arise from fewer complications, reduced device replacements, and lower hospitalization rates. Their successful integration requires alignment with multidisciplinary care bundles, staff training, careful patient selection, and adherence to maintenance protocols. Thus, surface-modified CVADs should be viewed not only as a biomaterial innovation but also as a practical tool for implementing best practices, bridging technology, clinical protocols, and patient-centered care. Long-term clinical validation, cost-effectiveness assessments, and real-world implementation studies remain essential to guide widespread adoption and maximize patient benefit.203
7. Challenges and perspectives
CVADs remain essential for life-saving therapies such as hemodialysis and chemotherapy. Despite decades of technological evolution, CVADs are not exempt from complications, and bloodstream infections and thrombosis continue to represent the most frequent complications in kidney and cancer patients, driving morbidity and imposing significant burdens on healthcare systems.204 Outcomes are influenced by both patient-specific factors and device-intrinsic properties, including material composition, surface characteristics, and design features, highlighting the need for an integrated, biomaterials-focused approach to improve vascular access safety. While clinical guidelines provide evidence-based recommendations for device selection, placement, maintenance, and complication prevention, persistent high rates of infection and thrombosis indicate that adherence to best practice alone is insufficient. While evidence on surface modification strategies is constrained by small, single-center studies, emphasizing the need for large multicenter trials, their challenging implementation underscores the importance of technological improvement in device design and materials, and highlights biomaterial innovation as a key strategy to bridge the gap between guidelines and real-world outcomes. Current technological approaches in surface modification represent a step forward, with some promising options already available in clinical practice, although most remain limited to addressing either infection or thrombosis. Most current solutions are limited in scope, applying only to certain types of catheters, and are often hampered by concerns regarding durability, cost-effectiveness, microbial resistance, and limited safety or efficacy data.205 More research is therefore necessary to optimise the technological development of CVADs and to find effective solutions that could help minimise the risk of device-related infections and thrombosis. Future biomaterials research should focus on developing multifunctional, durable, and clinically validated surface technologies that can be applied to both external and internal CVAD surfaces to improve long-term outcomes for patients requiring vascular access.
7.1 Limitations
This review has several limitations. As a narrative synthesis, it may be subject to selection bias, while heterogeneity in study design, populations, and outcome definitions limits comparability across trials. Most evidence on surface modification strategies comes from small, single-center studies with short follow-up, reducing the strength of clinical inferences. Moreover, guideline implementation across healthcare systems was not systematically assessed, potentially affecting the generalizability of some recommendations.
8. Conclusions
CVADs are indispensable for life-saving therapies but continue to be challenged by complications, primarily infection and thrombosis. While clinical guidelines help mitigate these risks, technological innovation, particularly in biomaterials and surface modification, remains critical to overcoming current limitations. Most existing strategies are uni-functional or lack long-term clinical validation, emphasizing the need for durable, multifunctional, and clinically tested surface technologies. Interdisciplinary biomaterials research integrating engineering, chemistry, and clinical science will be key to advancing the safety, efficacy, and long-term performance of CVADs, ultimately improving patient outcomes.
Ethics and consent
Ethical approval and consent were not required.
Declaration of AI and AI-assisted technologies in the writing process
During the preparation of this work, the authors used ChatGPT by OpenAI to support language refinement. After using this tool/service, the authors critically reviewed and edited the content as needed and take full responsibility for the content of the publication.
