The Natural History of Tunneled Hemodialysis Catheters Removed or Exchanged: A Single-Institution Experience

Long-Term Durability of Tunneled Hemodialysis Catheters: Outcomes from a Single Institution 22-Year Experience

PURPOSE

To describe long-term physical durability of tunneled hemodialysis catheters, highlighted in the 2019 Kidney Disease Outcomes Quality Initiative (KDOQI) guidelines as a specific area for future research.

MATERIALS AND METHODS

Tunneled hemodialysis catheters with known outcomes and dwell times > 1 year were entered into this retrospective study. Data includes demographics, complications, catheter type, dwell time, reason for removal, access site, and placement via exchange or de novo. Catheter durability < 1 year dwell was analyzed as a secondary aim.

RESULTS

272 catheters in 229 patients were included. Dwell times ranged from 366 to 3,802 days (median 504), totaling 162,439 catheter days. 17 (6%) catheters > 1 year dwell had broken external components. For these, dwell times until breaking ranged from 377 to 1,436 days (median 489), totaling 10,434 catheter days. 5 had a broken hub, 11 had a broken clamp, and 1 had broken hub and clamp. 12 were Ash Split Cath (n = 240) and 5 were Arrow-Clark VectorFlow (n = 32). In the durability < 1 year sub-analysis, 6,515 catheters with dwell times < 1 year in 3,693 patients were included, totaling 425,018 catheter days. 48 were damaged, with 24 broken hubs, 17 broken clamps, and 7 holes. Median time to breakage was 110 days. 38 were Ash Split Cath (n = 5,636) and 10 Arrow-Clark VectorFlow (n = 812). In both analyses, breakage was limited to hubs, clamps, and extensions.

CONCLUSIONS

Tunneled hemodialysis catheters are exceptionally durable, rarely requiring removal for hub-related issues after one year. Breakdown was not observed as a long-term durability issue. Further, broken external components can be replaced using external repair kits.

LEVEL OF EVIDENCE

Level 2b, Retrospective Study.

Long-Term Tunneled Hemodialysis Catheters: Achieving Efficiency Through Tip Position Optimization

BACKGROUND

This retrospective study assesses the influence of tunneled hemodialysis catheter tip location and lateralization on catheter-related complications, including dysfunction and catheter-related bloodstream infection.

METHODS

Using data from 162 patients who underwent catheter placement between January 2017 and December 2020, postoperative chest X-rays and clinical records were reviewed. Outcomes were assessed based on catheter removal duration and complication incidence.

RESULTS

Out of 177 catheter placements, 56 (32%) patients experienced complications during an average 530-day follow-up. Catheters placed in the superior vena cava (SVC) exhibited more severe complications with shorter dwell times compared with those in the pericavoatrial junction (pCAJ) or right atrium (RA). Moreover, complication rates were significantly higher (P < 0.01) in the SVC (1.91 per 1000 catheter days) compared with the pCAJ (0.54) or RA (0.47). Lateralization (right or left internal jugular vein) did not significantly affect the complication rates (0.60 vs. 0.58; P = 0.90). However, in subgroup analysis, a significantly higher complication rate was observed for catheters with tips inserted from the left side into the SVC than for those inserted from the right side (6.6 vs. 1.5; P < 0.01).

CONCLUSIONS

Catheters with tips in the SVC exhibited more severe complications than those in the pCAJ or RA, with left-side insertion of SVC-tipped catheters resulting in significantly higher complication rates compared with right-side insertion. These findings highlight the importance of optimal catheter tip positioning in long-term hemodialysis care to minimize complications and enhance patient outcomes.

Infectious outcomes of fibrin sheath disruption in tunneled dialysis catheters

BACKGROUND AND OBJECTIVES

Fibrin sheath (FS) formation around tunneled central venous catheters (CVC) increases the risk of catheter-related bloodstream infections due to bacterial adherence to a biofilm. We sought to investigate whether FS disruption (FSD) at the time of CVC removal or exchange affects infectious outcomes in patients with CVC-related infections.

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

Retrospective cohort study of 307 adult maintenance hemodialysis patients aged 18 years or older at a single center academic-based hemodialysis program (UHN, Toronto) who developed CVC-related infections requiring CVC removal or exchange between January 2000 and January 2019. Exposure was FSD at the time of CVC removal or exchange. Outcomes were infectious metastatic complications, recurrent infection with the same organism within 1 year, or death due to infection. We created a Markov Multi-State Model (MMSM) to assess patients' trajectories through time as they transitioned between states. A time-to-event analysis was performed, adjusted for clinically relevant factors.

RESULTS

There was no significant relationship between FSD status at the time of CVC removal, the development of infectious complications in the multivariable model (adjusted HR = 0.71, 95% CI 0.09-5.80, p = 0.76), or mortality from infection (HR = 0.84, 95% CI 0.34-2.11, p = 0.73).

CONCLUSIONS

FSD at the time of CVC removal was not associated with increased risk of infectious complications or death due to infection. Further prospective study is needed to determine whether FSD contributes to reducing CVC infectious related complications.

Efficacy and Safety of Bedside Removal of Tunnelled Hemodialysis Catheter by Noninterventional Nephrologists among Adult Patients in the King Abdulaziz University Hospital Hemodialysis Centre in Jeddah: A Retrospective Cohort Study

This study aimed to assess the efficacy and safety of bedside removal of tunnelled hemodialysis catheter (TDC) by noninterventional nephrologists among adult patients. It is a retrospective study that involved 53 patients from March 2020 to February 2022 at the King Abdulaziz University Hospital (KAUH) Hemodialysis Centre in Jeddah, Saudi Arabia. Of the 53 participants, 60.4% were male and 40.6% female, and their mean age was 50.94 ± 18.89 years. The most common comorbidities were hypertension (HTN) in 47 (88.7%), diabetes mellitus (DM) in 24 (45.3%), and DM and HTN together in 23 (43.4%) patients. The most common site of TDC removal was the right internal jugular vein (77.4%). In 84.9% of the cases, the TDC was removed as an inpatient procedure, and in the majority of the cases (64.2%), the TDC was removed by a noninterventional nephrologist. The most common reasons for TDC removal were sepsis or clinical concerns for infection (64.2%) and TDC not needed (20.8%) due to recovery of the renal function or access maturation. Most patients (96.2%) suffered no complications; only one of 34 (%) patients with catheter removal by a noninterventional nephrologist had bleeding, which required more observation and monitoring before discharge on the same day. Our study revealed that the bedside TDC removal was well tolerated with a minimal complication rate.

Cationic Alternating Polypeptide Fixed on Polyurethane at Multiple Sites for Excellent Antibacterial and Antifouling Properties

Bacterial infection and blockage are severe problems for polyurethane (PU) catheters and there is an urgent demand for surface-functionalized polyurethane. Herein, a cationic alternating copolymer comprising allyl-substituted ornithine and glycine (allyl-substituted poly(Orn-alter-Gly)) with abundant carbon-carbon double bond functional groups (C═C) is designed. Polyurethane is prepared with a large quantity of C═C groups (PU-D), and different amounts of allyl-substituted poly(Orn-alter-Gly) are grafted onto the PU-D surface (PU-D-2%AMPs and PU-D-20%AMPs) via the C═C functional groups. The chemical structures of the allyl-substituted poly(Orn-alter-Gly) and polyurethane samples (PU, PU-D, PU-D-2%AMPs, and PU-D-20%AMPs) are characterized and the results reveal that allyl-substituted poly(Orn-alter-Gly) is decorated on the polyurethane. PU-D-20%AMPs shows excellent antibacterial activity against Escherichia coli, Enterococcus faecalis, and Staphylococcus aureus because of the high surface potential caused by cationic allyl-substituted poly(Orn-alter-Gly), and it also exhibits excellent long-term antibacterial activity and antibiofilm properties. PU-D-20%AMPs also has excellent antifouling properties because the cationic copolymer is fixed at multiple reactive sites, thus avoiding the formation of movable long chain brush. A strong surface hydration barrier is also formed to prevent adsorption of proteins and ions, and in vivo experiments reveal excellent biocompatibility. This flexible strategy to prepare dual-functional polyurethane surfaces with antibacterial and antifouling properties has large potential in biomedical implants.

Fibrin sheath disruption during guidewire exchange for bacteremia: Low recurrence of infection and preservation of vascular access sites

BACKGROUND

Catheter-associated bacteremia (CAB) often leads to removal of tunneled dialysis catheters with delayed insertion (RDI). Exchange over a guidewire (ExW) can be considered for access site preservation. Fibrin sheath disruption (FSD) during exchange is not standard practice for infected catheters. Here we present the first analysis of outcomes after such exchanges (ExW-FSD).

METHODS

Retrospective analysis of catheter exchanges and removals performed by interventional nephrology for bacteremia in 2008-2011 observed for 20.5 months. Charts were reviewed for recurrent or new bacteremia and death at 3 months, and for occurrence of thrombosis or stenosis along the catheter site. Catheter exchange with central venogram and fibrin sheath disruption was our standard of care in all patients presenting for CAB. RDI was performed either for tunnel infection, non-clearing of infection or at the request of referring physicians.

RESULTS

Over 4 years, 66 patients were treated for CAB. Forty-two patients underwent ExW-FSD, which was performed even for Staph. aureus, gram negative bacteremia or candidemia. RDI was performed in 24 cases. Bacteremia recurred in 3 (7%) patients after ExW-FSD, and in 7 (30%) cases after RDI (p = 0.02). There was no significant difference in new infections: 5 (12%) after ExW-FSD and 2 (8%) after RDI. There was no death within 3 months after ExW-FSD and 4 (27%) (p = 0.005) deaths in the RDI group.There was one new central venous stenosis in the ExW-FSD group (2%) with no loss of access site, and 8 (33%) patients developed thrombosis/stenosis along the prior catheter track after RDI (33%) (p = 0.006) with loss of access site in (21%).

CONCLUSIONS

In this retrospective analysis of treatment of CAB, ExW-FSD was associated with lower recurrence of bacteremia, lower death rate and a lower incidence of access site loss compared to RDI. These data support ExW-FSD use in patients with CAB.

Presence of retained calcified fibrin sheath after central venous catheter removal: A systematic literature review

Central venous catheters (CVC) are used in many clinical settings for a variety of indications. We performed a systematic literature review concerning case reports of retained calcified fibrin sheaths after dialysis CVC removal. The aim of our study was to systematize the knowledge regarding clinical management of this phenomenon, placing special emphasis on diagnostic radiological features in different imaging modalities, including chest radiography, echocardiography, computed tomography, and magnetic resonance imaging. We discuss the most common risk factors associated with this CVC complication. In our review, we found eight cases of hemodialysis patients. The most common risk factors associated with calcified fibrin sheath formation in the analyzed cases were pro-thrombotic and pro-calcification factors related to patient comorbidities, and prolonged catheter dwell time. Differentiating between a calcified fibrin sheath (present in about 6% of patients with long-term indwelling CVC as diagnosed by computed tomography) and a retained catheter tip can be challenging. The initial diagnosis based on imaging methods was incorrect in most of the analyzed cases. This suggests that some cases of retained fibrin sheaths may remain undetected or misinterpreted. This is important in patients with known pro-thrombotic and pro-calcification risk factors and prolonged catheter dwell time. Therefore, implementation of preventive strategies, familiarity with radiological findings of this phenomenon, comparison with previous imaging studies, and an overall comprehensive assessment with clinical data is imperative.

Ghost Catheter Fibrin Sleeve: Case Report and Literature Review

•

Prolonged indwelling CVC leads to the formation of a GCFS.

•

GCFS can persisit in the venous system after removal of CVC.

•

GCSF can be a nidus of infection or thrombus formation.

•

TEE can be used to diagnose the presence of GCSF.

Spontaneous Dislodgement of Tunneled Dialysis Catheters after De Novo versus Over-The-Wire-Exchange Placement

PURPOSE

To evaluate dislodgement of tunneled dialysis catheters (TDCs) in de novo (DN) placement with ultrasound versus over-the-wire exchange (OTWE).

MATERIALS AND METHODS

Data were collected retrospectively on all TDC placements at this institution from 2001 to 2019 and were excluded if no removal date was recorded or if dwell time was more than 365 days. Information on TDC brand, placement, insertion/removal, and removal reason were collected. Multiple logistic regression evaluated factors associated with TDC dislodgement. DN placement and OTWE were compared for rate of dislodgement (generalized estimating equations method) and TDC dwell time (survival analysis).

RESULTS

In total, 5328 TDCs were included with 66% (3522) placed DN and 32% (1727) via OTWE. Mean dwell time was 65 ± 72 days, and dislodgement occurred in 4% (224). TDC dislodgement rates in the DN and OTWE groups were 0.48 and 0.93 per 1000 catheter days, respectively. Brand (Ash Split vs. VectorFlow), placement technique (OTWE vs. DN), laterality (left vs. right), and site (left vs. right internal jugular vein) were significant predictors of dislodgement. OTWE placement exhibited 1.7 times the odds of dislodgement (95% confidence interval, 1.2-2.6; P = .004) compared to DN and had significantly higher probability of dislodgement across time (hazard ratio = 2.0; P < .001) compared to DN. Dislodgement rates for OTWE vs. DN were 8% vs. 3% (3 months), 13% vs. 6% (6 months), and 38% vs. 17% (1 year).

CONCLUSIONS

TDC spontaneous dislodgement rates were significantly and consistently higher after OTWE compared to DN placement. These data support more careful attention to catheter fixation after OTWE placement.

Minimising Blood Stream Infection: Developing New Materials for Intravascular Catheters

Catheter related blood stream infection is an ever present hazard for those patients requiring venous access and particularly for those requiring long term medication. The implementation of more rigorous care bundles and greater adherence to aseptic techniques have yielded substantial reductions in infection rates but the latter is still far from acceptable and continues to place a heavy burden on patients and healthcare providers. While advances in engineering design and the arrival of functional materials hold considerable promise for the development of a new generation of catheters, many challenges remain. The aim of this review is to identify the issues that presently impact catheter performance and provide a critical evaluation of the design considerations that are emerging in the pursuit of these new catheter systems.

The fibroblastic sleeve, the neglected complication of venous access devices: A narrative review

The presence of a vascular access device (or of any intravascular foreign body) inside the bloodstream is often associated with the formation of a connective tissue sleeve around the catheter (often named-erroneously-"fibrin sleeve"). Such sleeve is usually a physiological phenomenon with little or no clinical relevance, but its pathogenesis is still unclear, so that it is frequently confused with venous thrombosis; also, its relationship with other major catheter-related complications, such as venous thrombosis and bloodstream infection, is uncertain. This narrative review tries to convey in a systematic form the current knowledge about pathogenesis, incidence, clinical manifestations, diagnosis, and management of this phenomenon.

Lewitus D. The Grafting of Multifunctional Antithrombogenic Chemical Networks on Polyurethane Intravascular Catheters

Intravascular catheters (IVCs) and other medical tubing are commonly made of polymeric materials such as polyurethane (PU). Polymers tend to be fouled by surface absorption of proteins and platelets, often resulting in the development of bacterial infections and thrombosis during catheterization, which can lead to embolism and death. Existing solutions to fouling are based on coating the IVCs with hydrophilic, anti-thrombogenic, or antimicrobial materials. However, the delamination of the coatings themselves is associated with significant morbidity, as reported by the United States Food and Drug Administration (FDA). We developed a lubricious, antimicrobial, and antithrombogenic coating complex, which can be covalently attached to the surface of industrial PU catheters. The coating complex is pre-synthesized and comprises 2-methacryloyloxyethyl phosphorylcholine (MPC) as an antifouling agent, covalently attached to branched polyethyleneimine (bPEI) as a lubricating agent. The two-step coating procedure involves PU-amine surface activation using a diisocyanate, followed by chemical grafting of the bPEI-S-MPC complex. Compared with neat PU, the coating was found to reduce the coefficient of friction of the IVC surface by 30% and the hemolysis ratio by more than 50%. Moreover, the coating exhibited a significant antimicrobial activity under JIS Z2801:2000 standard compared with neat PU. Finally, in in-vivo acute rabbit model studies, the coating exhibited significant antithrombogenic properties, reducing the thrombogenic potential to a score of 1.3 on coated surfaces compared with 3.3 on uncoated surfaces. The materials and process developed could confer lubricious, antithrombogenic, and antimicrobial properties on pre-existing PU-based catheters.

KDOQI Clinical Practice Guideline for Vascular Access: 2019 Update

The National Kidney Foundation's Kidney Disease Outcomes Quality Initiative (KDOQI) has provided evidence-based guidelines for hemodialysis vascular access since 1996. Since the last update in 2006, there has been a great accumulation of new evidence and sophistication in the guidelines process. The 2019 update to the KDOQI Clinical Practice Guideline for Vascular Access is a comprehensive document intended to assist multidisciplinary practitioners care for chronic kidney disease patients and their vascular access. New topics include the end-stage kidney disease "Life-Plan" and related concepts, guidance on vascular access choice, new targets for arteriovenous access (fistulas and grafts) and central venous catheters, management of specific complications, and renewed approaches to some older topics. Appraisal of the quality of the evidence was independently conducted by using a Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach, and interpretation and application followed the GRADE Evidence to Decision frameworks. As applicable, each guideline statement is accompanied by rationale/background information, a detailed justification, monitoring and evaluation guidance, implementation considerations, special discussions, and recommendations for future research.

Spanish Clinical Guidelines on Vascular Access for Haemodialysis

Vascular access for haemodialysis is key in renal patients both due to its associated morbidity and mortality and due to its impact on quality of life. The process, from the creation and maintenance of vascular access to the treatment of its complications, represents a challenge when it comes to decision-making, due to the complexity of the existing disease and the diversity of the specialities involved. With a view to finding a common approach, the Spanish Multidisciplinary Group on Vascular Access (GEMAV), which includes experts from the five scientific societies involved (nephrology [S.E.N.], vascular surgery [SEACV], vascular and interventional radiology [SERAM-SERVEI], infectious diseases [SEIMC] and nephrology nursing [SEDEN]), along with the methodological support of the Cochrane Center, has updated the Guidelines on Vascular Access for Haemodialysis, published in 2005. These guidelines maintain a similar structure, in that they review the evidence without compromising the educational aspects. However, on one hand, they provide an update to methodology development following the guidelines of the GRADE system in order to translate this systematic review of evidence into recommendations that facilitate decision-making in routine clinical practice, and, on the other hand, the guidelines establish quality indicators which make it possible to monitor the quality of healthcare.

Location and structure of fibrous sheath formed after placing a tunneled hemodialysis catheter in a large pig model

BACKGROUND AND OBJECTIVES

We evaluated the location and structure of the fibrous sheath formed after the placement of tunneled, cuffed hemodialysis catheters in large animals, 70 kg pigs. We focused on describing the location of the fibrous sheath in relation to the catheter. Its location explains the fibrous sheath's ability to cause catheter dysfunction by covering the catheter exit ports located at the catheter's tip.

DESIGN

We used three animals. Each animal had a tunneled, cuffed, 15-French diameter hemodialysis catheter placed in the external jugular vein, with the tip at the junction of the superior vena cava and the right atrium. Two animals were sacrificed at 5 weeks and one animal at 17 weeks after catheter placement. The catheter and surrounding tissues were removed in one block. The fibrous sheath was dissected and longitudinally cut along the catheter to evaluate its extension in relation to the catheter. Relevant portions of the fibrous sheath were sent for pathology examination.

RESULTS

The fibrous sheath covered the catheter in its entire length and circumference. It started at the entry site and continued without any interruption along the entire length of the catheter, including the tip. Its average thickness is 1 mm and has an inner cellular/inflammatory layer comprising lymphocytes, plasma cells, neutrophils, macrophages, multinucleated giant cells, and spindled cells and an outer layer comprising a mixture of collagen and fibroblasts.

CONCLUSION

Our model showed that the fibrous sheath forms around all catheters and covers them in their entire length and circumference without any gaps.

Longitudinal dialysis adequacy and clinical performance of the VectorFlow hemodialysis catheter: a prospective study

PURPOSE

To report clinical performance and longitudinal assessment of hemodialysis adequacy with the Arrow-Clark VectorFlow catheter, a symmetrical-tip device with a distal lumen configuration designed to reduce platelet shear stress and catheter thrombosis.

METHODS AND MATERIALS

We prospectively enrolled patients who required de novo placement of a chronic tunneled catheter for hemodialysis or exchange of a dysfunctional catheter as part of an Institutional Review Board (IRB)-approved protocol. Catheter patency, Kt/V, mean blood-flow (Qb), and pump pressures were obtained at baseline and at monthly intervals to 90 days.

RESULTS

Forty-six subjects were enrolled into the study. During the 90-day observation period, maximum blood-flow rate averaged 355-398 mL/minute; mean Qb averaged 333-392 mL/minute. Mean Kt/V values were consistently ≥1.5. Dwell-time was 15-114 days, for a total of 2997 catheter days (mean 71.4 days). Excluding patients who died during the study and those receiving surgical access, overall intervention-free catheter patency rate was 94.9%, 92.2% and 88.8% at days 30, 60, 90, respectively. There were no acute complications. During the follow-up period, three patients developed complications (6.5%). Two catheter infections occurred (0.7/1000 catheter days) and one catheter malfunctioned; a rate of 1.0/ 1000 catheter days for all complications.

CONCLUSIONS

The VectorFlow catheter produced safe, effective hemodialysis with Kt/V ≥1.5. A single catheter occlusion occurred and a low rate of infection was seen. Results support the hypothesis that the VectorFlow design reduces thrombogenic risk during clinical performance.

Interventions for treating central venous haemodialysis catheter malfunction

BACKGROUND

Adequate haemodialysis (HD) in people with end-stage kidney disease (ESKD) is reliant upon establishment of vascular access, which may consist of arteriovenous fistula, arteriovenous graft, or central venous catheters (CVC). Although discouraged due to high rates of infectious and thrombotic complications as well as technical issues that limit their life span, CVC have the significant advantage of being immediately usable and are the only means of vascular access in a significant number of patients. Previous studies have established the role of thrombolytic agents (TLA) in the prevention of catheter malfunction. Systematic review of different thrombolytic agents has also identified their utility in restoration of catheter patency following catheter malfunction. To date the use and efficacy of fibrin sheath stripping and catheter exchange have not been evaluated against thrombolytic agents.

OBJECTIVES

This review aimed to evaluate the benefits and harms of TLA, preparations, doses and administration as well as fibrin-sheath stripping, over-the-wire catheter exchange or any other intervention proposed for management of tunnelled CVC malfunction in patients with ESKD on HD.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Specialised Register up to 17 August 2017 through contact with the Information Specialist using search terms relevant to this review. Studies in the Specialised Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal, and ClinicalTrials.gov.

SELECTION CRITERIA

We included all studies conducted in people with ESKD who rely on tunnelled CVC for either initiation or maintenance of HD access and who require restoration of catheter patency following late-onset catheter malfunction and evaluated the role of TLA, fibrin sheath stripping or over-the-wire catheter exchange to restore catheter function. The primary outcome was be restoration of line patency defined as ≥ 300 mL/min or adequate to complete a HD session or as defined by the study authors. Secondary outcomes included dialysis adequacy and adverse outcomes.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed retrieved studies to determine which studies satisfy the inclusion criteria and carried out data extraction. Included studies were assessed for risk of bias. Summary estimates of effect were obtained using a random-effects model, and results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes, and mean difference (MD) and 95% CI for continuous outcomes. Confidence in the evidence was assessed using GRADE.

MAIN RESULTS

Our search strategy identified 8 studies (580 participants) as eligible for inclusion in this review. Interventions included: thrombolytic therapy versus placebo (1 study); low versus high dose thrombolytic therapy (1); alteplase versus urokinase (1); short versus long thrombolytic dwell (1); thrombolytic therapy versus percutaneous fibrin sheath stripping (1); fibrin sheath stripping versus over-the-wire catheter exchange (1); and over-the-wire catheter exchange versus exchange with and without angioplasty sheath disruption (1). No two studies compared the same interventions. Most studies had a high risk of bias due to poor study design, broad inclusion criteria, low patient numbers and industry involvement.Based on low certainty evidence, thrombolytic therapy may restore catheter function when compared to placebo (149 participants: RR 4.05, 95% CI 1.42 to 11.56) but there is no data available to suggest an optimal dose or administration method. The certainty of this evidence is reduced due to the fact that it is based on only a single study with wide confidence limits, high risk of bias and imprecision in the estimates of adverse events (149 participants: RR 2.03, 95% CI 0.38 to 10.73).Based on the available evidence, physical disruption of a fibrin sheath using interventional radiology techniques appears to be equally efficacious as the use of a pharmaceutical thrombolytic agent for the immediate management of dysfunctional catheters (57 participants: RR 0.92, 95% CI 0.80 to 1.07).Catheter patency is poor following use of thrombolytic agents with studies reporting median catheter survival rates of 14 to 42 days and was reported to improve significantly by fibrin sheath stripping or catheter exchange (37 participants: MD -27.70 days, 95% CI -51.00 to -4.40). Catheter exchange was reported to be superior to sheath disruption with respect to catheter survival (30 participants: MD 213.00 days, 95% CI 205.70 to 220.30).There is insufficient evidence to suggest any specific intervention is superior in terms of ensuring either dialysis adequacy or reduced risk of adverse events.

AUTHORS' CONCLUSIONS

Thrombolysis, fibrin sheath disruption and over-the-wire catheter exchange are effective and appropriate therapies for immediately restoring catheter patency in dysfunctional cuffed and tunnelled HD catheters. On current data there is no evidence to support physical intervention over the use of pharmaceutical agents in the acute setting. Pharmacological interventions appear to have a bridging role and long-term catheter survival may be improved by fibrin sheath disruption and is probably superior following catheter exchange. There is no evidence favouring any of these approaches with respect to dialysis adequacy or risk of adverse events.The current review is limited by the small number of available studies with limited numbers of patients enrolled. Most of the studies included in this review were judged to have a high risk of bias and were potentially influenced by pharmaceutical industry involvement.Further research is required to adequately address the question of the most efficacious and clinically appropriate technique for HD catheter dysfunction.

Catheter Failure and Mortality in Hemodialysis Patients with Tunneled Cuffed Venous Catheters in a Single Center

Background: As of now, only a few studies have focused on the failure of tunneled cuffed venous catheter (tCVC) and mortality of hemodialysis (HD) patients using tCVC as long-term vascular access, whose vascular condition for arteriovenous fistula was not very satisfactory. In this study, we aimed to provide information about the first tCVC failure and survival rates of patients in this population. Methods: Fifty-nine patients who used tCVC from January 1, 2009 to December 31, 2014 in our HD center were analyzed in this retrospective study and followed up either until their death or until December 31, 2015. The first tCVC and patient survival rates were analyzed. Results: The incidence of catheter-related infections was 0.3 per 1,000 patient-days. The median survival duration of first tCVC was 45.0 (95% CI 29.3-69.7) months and the median survival time of all patients was 56.3 (95% CI 34.1-78.5) months by Kaplan-Meier analysis. Advanced age (hazard ratio [HR] 1.055, p < 0.05) and diabetic mellitus (HR 4.147, p < 0.05) at the initiation of HD were significant risk factors of first tCVC failure, while male (HR 2.712, p < 0.05) and cardiovascular diseases (CVDs; HR 4.139, p < 0.05) were significant risk factors for patient mortality as deduced by Cox proportional hazards methods. Conclusions: The study highlighted that first tCVC survival rates and patient survival rates were high in HD patients who were using tCVCs as long-term vascular access, with low incidence of catheter-related infections. In the study it was found that advanced age and diabetic mellitus at the initiation of HD influenced first tCVC failure, whereas male and CVDs seemed to be risk factors for patient mortality.

Complications in Percutaneous Dialysis Interventions: How to Avoid Them, and How to Treat Them When They do Occur

Because of the increasing prevalence of end-stage renal disease, more percutaneous interventions are being performed. They serve an important role, allowing for restoration of access function, which is achieved with high level of technical success. However, complications are inevitable during any types of procedure, and percutaneous dialysis interventions are no exception. To provide safe and effective care these patients need, anyone performing endovascular dialysis interventions needs to understand the possible complications, how they can be avoided, and how they can be addressed if they are to occur. Topics in this article include complications seen while intervening on the thrombosed access, complications of angioplasty, potentially devastating complications of central venous interventions, and complications of dialysis catheter placement. Further, patients with end-stage renal disease are generally sicker than the average patient, usually afflicted by multiple comorbidities and are therefore more complicated from a medical perspective. This places them at higher risk for acute cardiopulmonary decompensation or arrest than any other interventional radiology patient subset. As result, we also briefly review general medical complications in this population.

Treatment of Tunneled Dialysis Catheter Malfunction: Revision versus Exchange

Introduction

Exchange procedures involve tunneled dialysis catheter (TDC) removal and exchange over a wire, using the same exit site and venotomy site. Diagnostic imaging or intervention was generally not performed in exchange procedures. Revision procedures involve placement of new TDC using the previous venotomy site and a new tunnel and exit site. The majority of revisions usually include diagnostic imaging and intervention in the central circulation if needed.

Methods

A retrospective single review of 70 patients who underwent 97 TDC replacements from 2010 to early 2012 because of catheter malfunction was evaluated for either infection or malfunction within 30 days of the procedure.

Results

There were 41 exchanges and 56 revisions out of the 97 procedures performed. There were eight infections (documented by positive blood culture) in the exchanges (19.5%) and one in the revision group (1.8%). The need for an additional procedure due to malfunction was 10 in the exchange (24.4%) and 10 (17.8%) in the revision group.

Conclusions

Revision is a clearly superior procedure with regard to infection and more data need to be gathered as to whether it will decrease repeat procedures.

The safety and efficacy of bedside removal of tunneled hemodialysis catheters by nephrology trainees

BACKGROUND

Some nephrologists remove tunneled hemodialysis catheters (TDC) at the bedside, but this practice has never been formally studied. Our hypothesis was that bedside removal of TDC is a safe and effective procedure affording prompt removal, including in cases of suspected infection.

METHODS

We reviewed our consecutive 3-year experience (2007-2009) with bedside TDC removal at the University of Mississippi Renal Fellowship Program. Data were collected on multiple patients and procedure-related variables, success and complication rates. Association between clinical characteristics and biomarkers of inflammation and myocardial damage was examined using correlation coefficients.

RESULTS

Of 55 inpatient TDC removals (90.9% from internal jugular location), 50 (90.9%) were completed without hands-on assistance from faculty. Indications at the time of removal included bacteremia, fever or clinical sepsis with hemodynamic instability or respiratory failure. All procedures were successful, with no cuff retention noted; one patient experienced prolonged bleeding which was controlled with local pressure. Peak C-reactive protein (available in 63.6% of cohort) was 12.9 ± 8.4 mg/dL (reference range: <0.49) and median troponin-I (34% available) was 0.534 ng/mL (IQR 0.03-0.9) (reference range: <0.034) and they did not correlate with each other. Abnormal troponin-I was associated with proven bacteremia (p < 0.05) but not with systolic and diastolic BP or clinical sepsis.

CONCLUSION

Our results suggest that bedside removal of TDC remains a safe and effective procedure regardless of site or indications. Accordingly, TDC removal should be an integral part of competent Nephrology training.

A single institutional experience of conversion of non-tunneled to tunneled hemodialysis catheters: a comparison to de novo placement

PURPOSE

To compare the outcomes of conversion of non-tunneled to tunneled hemodialysis catheters with de novo placement of tunneled catheters and to determine the effect of time to conversion of non-tunneled to tunneled catheters on the incidence of complications.

MATERIALS AND METHODS

A retrospective data analyses was performed on 1,154 patients who had de novo placement of tunneled hemodialysis catheters (control group) and 254 patients who underwent conversion of non-tunneled to tunneled catheters (study group). The outcomes including technical complications, infection, and catheter dysfunction were compared between the two groups.

RESULTS

The technical success rate was 100 % in both the groups with no complications recorded at the time of procedure or within 24 h of insertion. The most common complication encountered in both the groups was catheter dysfunction (15.6 % in controls and 18.1 % in study). Infection rates/100 catheter days for the control and study groups were 0.17 and 0.19, respectively. Infection-free survival was not statistically different between the two groups. The time spent with non-tunneled catheter prior to conversion did not significantly alter the rates of catheter dysfunction and infection in the study group.

CONCLUSION

The efficacy and safety of conversion of non-tunneled to tunneled hemodialysis catheters are similar to de novo placement with no difference in the rates of technical success, catheter dysfunction, or infection. However, the exchange of non-tunneled to tunneled catheter can help in preservation of veins for future vascular access, which is of vital importance in patients with chronic renal disease.

Natural history of tunneled dialysis catheters placed for hemodialysis initiation

PURPOSE

More than 80% of hemodialysis recipients in the United States initiate hemodialysis with a tunneled dialysis catheter (TDC). Published data on TDC outcomes are based on a case mix of prevalent and incident TDCs. The present study analyzes factors affecting patency and complications of first TDCs placed in a large cohort of incident hemodialysis recipients.

MATERIALS AND METHODS

A prospective, computerized vascular access database was retrospectively queried to identify 472 patients receiving a first-ever TDC. Multiple-variable survival analysis was used to identify clinical parameters affecting TDC patency (from placement to nonelective removal) and infection (from placement to first episode of catheter-related bacteremia [CRB]).

RESULTS

The median patency of all TDCs was 202 days. Left-sided placement of TDCs was the only variable associated with inferior TDC patency (hazard ratio, 1.98; 95% confidence interval, 1.39-2.81; P < .0001). The 6-month TDC patency rate was 37% for left internal jugular vein (LIJV) catheters, versus 54% for right internal jugular vein (RIJV) catheters. The 1-year patency rate was 6% for LIJV catheters, versus 35% for RIJV catheters. Catheter patency was not associated with patient age, sex, race, hypertension, diabetes, coronary artery disease, peripheral vascular disease, cerebrovascular disease, or heart failure. The median time to the first episode of CRB was 163 days. None of the clinical variables was associated with TDC infection.

CONCLUSIONS

TDCs are plagued by high rates of infection. RIJV TDCs should be used preferentially to maximize catheter patency.

Staphylococcus-infected tunneled dialysis catheters: is over-the-wire exchange an appropriate management option?

PURPOSE

Over-the-wire exchange of tunneled dialysis catheters is the standard of care per K/DOQI guidelines for treating catheter-related bacteremia. However, Gram-positive bacteremia, specifically with staphylococcus species, may compromise over-the-wire exchange due to certain biological properties. This study addressed the effectiveness of over-the-wire exchange of staphylococcus-infected tunneled dialysis catheters compared with non-staphylococcus-infected tunneled dialysis catheters.

METHODS

Patients who received over-the-wire exchange of their tunneled dialysis catheter due to documented or suspected bacteremia were identified from a QA database. Study patients (n = 61) had positive cultures for Staphylococcus aureus, Staphylococcus epidermidis, or coagulase-negative staphylococcus not otherwise specified. Control patients (n = 35) received over-the-wire exchange of their tunneled dialysis catheter due to infection with any organism besides staphylococcus. Overall catheter survival and catheter survival among staphylococcal species were assessed.

RESULTS

There was no difference in tunneled dialysis catheter survival between study and control groups (P = 0.46). Median survival time was 96 days for study catheters and 51 days for controls; survival curves were closely superimposed. There also was no difference among the three staphylococcal groups in terms of catheter survival (P = 0.31). The median time until catheter removal was 143 days for SE, 67 days for CNS, and 88 days for SA-infected catheters.

CONCLUSIONS

There is no significant difference in tunneled dialysis catheter survival between over-the-wire exchange of staphylococcus-infected tunneled dialysis catheters and those infected with other organisms.

Interventions for preventing infectious complications in haemodialysis patients with central venous catheters

BACKGROUND

Central venous catheters (CVC) continue to play a prominent role in haemodialysis vascular access with 46% to 70% of patients commencing haemodialysis via a CVC. CVC access is associated with catheter-related infections, increased patient hospitalisations and death due to infection. A variety of interventions are used to prevent CVC infection.

OBJECTIVES

To evaluate the benefits and harms of prophylactic topical antimicrobials, topical antiseptics, medicated and non-medicated dressings on infectious complications among haemodialysis patients with CVC.

SEARCH STRATEGY

We searched the Cochrane Renal Group's specialised register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and reference lists of articles without language restriction.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs investigating any intervention that prevented infectious complications among haemodialysis patients with CVC. We excluded antimicrobial impregnated CVC or CVC using locking solutions with antimicrobial properties.

DATA COLLECTION AND ANALYSIS

Two authors assessed study quality and extracted data. Dichotomous outcomes were expressed as risk ratios (RR) with 95% confidence intervals (CI) and continuous outcomes as mean differences (MD).

MAIN RESULTS

Ten studies (786 patients) were included. Mupirocin ointment reduced the risk of catheter-related bacteraemia (RR 0.17, 95%CI 0.07 to 0.43) and had a significant effect on catheter-related infections caused by S. aureus. The risk of catheter-related bacteraemia was reduced by polysporin (RR 0.40, 95%CI 0.19 to 0.86) and povidone-iodine ointment (RR 0.10, 95%CI 0.01 to 0.72). Subgroup analysis suggested mupirocin (RR 0.12, 95%CI 0.01 to 2.13) and povidone-iodine ointment (RR 0.84, 95%CI 0.24 to 2.98) had no effect on all-cause mortality while polysporin ointment showed a significant reduction (RR 0.22, 95%CI 0.07 to 0.74). Mortality related to infection was not reduced by mupirocin, polysporin or povidone-iodine ointment. Topical honey did not reduce the risk of exit site infection (RR 0.45, 95%CI 0.10 to 2.11) or catheter-related bacteraemia (RR 0.80, 95%CI 0.37 to 1.73). Transparent polyurethane dressing compared to dry gauze dressing did not reduce the risk of CVC or exit site infection, or catheter-related bacteraemia.

AUTHORS' CONCLUSIONS

Mupirocin ointment appears effective in reducing the risk of catheter-related bacteraemia. Insufficient reporting on mupirocin resistance was noted and needs to be considered in future studies. A lack of high quality data on the routine use of povidone-iodine ointment, polysporin ointment and topical honey warrant larger RCTs. Insufficient data were available to determine which dressing type (transparent polyurethane or dry gauze dressing) has the lowest risk of catheter-related infections.

Malfunction of dialysis catheters: management of fibrin sheath and related problems

Suitable central venous access for hemodialysis is frequently required in patients with end-stage renal disease, whenever an arteriovenous fistula or peritoneal dialysis fails or is not a possibility. Ultimately, long-term dialysis via central access may result in dysfunctional catheter with problems such as malpositioning of catheter tip, fibrin sheath formation, thrombosis, infection, and bleeding. The role of interventional radiology is to deliver appropriate treatment to maintain patent and functional access, while minimizing the risk of venous occlusive disease. This article aims at describing different techniques and approaches for management of fibrin sheath associated with malfunctioning tunneled dialysis catheters, as well as to provide scientific evidence from the current literature.

The great saphenous vein for central venous access and haemodialysis

BACKGROUND

Utilising an open surgical technique the Great Saphenous vein in the proximal thigh can be used for the insertion of central venous catheters for haemodialysis. This approach is safe and efficacious, and may be performed under local or general anaesthesia. This technique is of particular importance in patients requiring vascular access for haemodialysis in whom the upper central veins are stenosed and the femoral vessels are not amenable to percutaneous cannulation.

METHODS

The Great saphenous vein is exposed via a surgical incision in the thigh. The central venous catheter is then inserted and advanced until in the desired position, as confirmed on fluoroscopy.

RESULTS

Seven Great saphenous catheters were placed over a period of six months. All catheters insertions were technical successes with completion of at least one dialysis session. Primary patency rates were 57%, 49%, 23% at 30, 60 and 90 days respectively.

CONCLUSION

The great saphenous vein offers an additional site for the insertion of central venous catheters. These data demonstrate equivalence in patency between this novel technique and percutaneous femoral vein cannulation.