Evaluating Short-Term Outcomes of Tunneled and Non-Tunneled Central Venous Catheters in Hemodialysis

Background: The necessity of using central venous catheters (CVCs) in hemodialysis, coupled with their associated complications, remains a critical concern in nephrology. This study aims to compare the short-term prognosis of tunneled (T-CVC) and non-tunneled (NT-CVC) CVCs in acute hemodialysis patients, specifically focusing on infection rates, malpositioning, and lumen thrombosis within the first three weeks post-insertion. Methods: A retrospective analysis was conducted on 176 CVCs placed between January and December 2023 at the Policlinico di Modena and the Ospedale Civile di Baggiovara. Patient demographics, CHA2DS2-VASc scores, and comorbid conditions were recorded at the time of catheter placement. Outcomes assessed included catheter-related infections, malpositioning, and lumen thrombosis. Statistical analyses, including Chi-square tests, Fisher's exact tests, and Kaplan-Meier survival analysis, were performed to evaluate differences between T-CVCs and NT-CVCs. Results: The sample comprised 43% females with a mean age of 69.3 years (SD 13.9) and a mean CHADS-VASC score of 3.72 (SD 1.4). Hypertension (90%) was the most prevalent comorbidity. Of the 176 CVCs, 127 were T-CVCs and 49 were NT-CVCs. Infection rates were 3.15% for T-CVCs and 8.16% for NT-CVCs (p = 0.07). Malpositioning occurred in 0.79% of T-CVCs and 4.08% of NT-CVCs (p = 0.47). There was one case of lumen thrombosis in the NT-CVC group. Kaplan-Meier analysis indicated a significant divergence in infection-related catheter survival favoring T-CVCs after ten days (p = 0.034). Conclusions: While non-tunneled CVCs do not significantly alter short-term prognosis compared to tunneled CVCs, the latter show a better infection-related survival rate beyond ten days. Therefore, primary insertion of T-CVCs may be preferable when resources and clinical conditions permit, although NT-CVCs remain a viable option when immediate T-CVC insertion is challenging.

Interleukin-6 and Outcome of Chronic Hemodialysis Patients with SARS-CoV-2 Pneumonia

Background and Objectives: Chronic hemodialysis (CHD) patients are at increased risk of SARS-CoV-2 infection and the related complications and mortality of COVID-19 due to the high rate of comorbidities combined with advanced age. This observational study investigated the clinical manifestations of SARS-CoV-2 infection in CHD and the risk factors for patients′ death. Materials and Methods: The study included 26 CHD patients with SARS-CoV-2 pneumonia detected by positive RT-PCR on nasopharyngeal swabs and high-resolution computed tomography at hospital admission, aged 71 + 5.9 years, 14 of which (53.8%) were male, 20 (77%) under hemodiafiltration, and 6 (23%) on standard hemodialysis, with a median follow-up of 30 days. Results: Simple logistic regression analysis revealed that the factors associated with a higher risk of death were older age (OR: 1.133; 95%CI: 1.028−1.326, p = 0.0057), IL-6 levels at admission (OR: 1.014; 95%CI: 1.004−1.028, p = 0.0053), and C-reactive protein (OR: 1.424; 95%CI: 1.158−2.044, p < 0.0001). In the multiple logistic regression model, circulating IL-6 values at admission remained the only significant prognosticator of death. The ROC curve indicated the discriminatory cut-off value of 38.20 pg/mL of blood IL-6 for predicting death in chronic hemodialysis patients with SARS-CoV-2 pneumonia (sensitivity: 100%; specificity: 78%; AUC: 0.8750; p = 0.0027). Conclusions: This study identified a threshold of IL-6 levels at hospital admission for death risk in CHD patients with SARS-CoV-2 pneumonia. This might represent a valuable outcome predictor, feasibly better than other clinical, radiological, or laboratory parameters and preceding the IL-6 peak, which is unpredictable.

Pathology of catheter-related complications: what we need to know and what should be discovered

Despite the considerable efforts made to increase the prevalence of autogenous fistula in patients on hemodialysis, tunneled cuffed catheters are still an important access modality and used in a high percentage of the hemodialysis population. However, because of the conundrum posed by tunneled cuffed catheters, patients can develop a multitude of complications, including thrombosis, infections, formation of a fibrin sheath, and central vein stenosis, resulting in increased morbidity and mortality as well as placing a heavy burden on the healthcare system. However, with an increasing number of studies now focusing on how to manage these catheter-related complications, there has been less translational research on the pathology of these complications. This review of the most recent literature provides an update on the pathological aspects of catheter-related complications, highlighting what we need to know and what is yet to be discovered. The future research strategies and innovations needed to prevent these complications are also addressed.

Prevention of tunneled cuffed catheter dysfunction with prophylactic use of a taurolidine urokinase lock: A randomized double-blind trial

Background

The efficacy and cost-effectiveness of prophylactic thrombolytic locks in hemodialysis patients at high-risk of thrombotic dialysis catheter dysfunction is uncertain. We investigated this question in a double-blinded randomized controlled study.

Methods

Prevalent hemodialysis patients from 8 Belgian hemodialysis units, with ≥2 separate episodes of thrombotic dysfunction of their tunneled cuffed catheter during the 6 months before inclusion, were randomized to either: taurolidine heparin locks thrice weekly (control arm) or the same locks twice a week combined with taurolidine urokinase locks once a week before the longest interval without HD (TaurolockU arm). The primary efficacy outcome was the incidence rate of catheter thrombotic dysfunction requiring thrombolytic locks to restore function.

Results

68 hemodialysis patients (32 controls, 36 urokinase) were followed during 9875 catheter days between May 2015 and June 2017. Incidence rate of thrombotic catheter dysfunction was 4.8 in TaurolockU vs 12.1/1000 catheter days in control group (rate ratio 0.39; 95%CI 0.23–0.64). 15/36 (42%) catheters in the treatment group required at least one therapeutic urokinase lock vs 23/32 (72%) in the control group (P = 0.012). The two groups did not differ significantly in catheter-related bloodstream infection and combined cost of prophylactic and therapeutic catheter locks. The TaurolockU group had a numerically higher number of episodes of refractory thrombosis.

Conclusions

Prophylactic use of urokinase locks is highly effective in reducing the number of thrombotic catheter dysfunctions in catheters with a history of recurring dysfunction. Prophylactic use of urokinase locks did not reduce the overall costs associated with catheter locks and was associated with a numerically higher number of episodes of refractory thrombosis.

Trial registration

ClinicalTrials.gov Identifier: NCT02036255.

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.

Comparative efficacy and safety of lock solutions for the prevention of catheter-related complications including infectious and bleeding events in adult haemodialysis patients: a systematic review and network meta-analysis

BACKGROUND

Central venous catheters are used extensively as temporary or permanent vascular access for haemodialysis patients. Catheter-related bloodstream infections are the main complication of central venous catheters and increase morbidity and mortality in haemodialysis patients.

OBJECTIVES

The aim was to assess the most appropriate lock solution for central venous catheters to prevent catheter-related bloodstream infections and other complications.

DATA SOURCES

Medline, Embase and the Cochrane Central Register of Controlled Trials from the date of their inception to August 2018 were used as data sources. The reference lists of eligible studies and relevant reviews were also checked.

STUDY ELIGIBILITY CRITERIA AND PARTICIPANTS

Randomized controlled trials (RCTs) comparing different lock solutions for the prevention of central venous catheter-related infectious and bleeding complications for adult dialysis patients were included.

INTERVENTIONS

Interventions were lock solutions for haemodialysis catheters.

METHODS

The primary outcomes were catheter-related bloodstream infections and bleeding events. The secondary outcomes were catheter malfunction, exit-site infection, and all-cause mortality. We estimated summary risk ratios (RRs) using pairwise and network meta-analysis. We assessed the risk of bias of individual studies with the Cochrane risk of bias tool.

RESULTS

Forty-nine trials (7020 patients) were included for this study. Compared with heparin 5000 U/mL, antibiotic locks (antibiotics with trisodium citrate (TSC), ethylenediamine tetraacetic acid (EDTA), heparin 5000 U/mL, low-dose heparin or urokinase) and ethanol locks were more effective in preventing catheter-related bloodstream infections. Antimicrobial agents plus low-dose heparin (500-2500 U/mL), TSC and low-dose heparin locks had lower risk of bleeding events than heparin 5000 U/mL. None of the lock solutions reduced rates of catheter malfunction and all-cause mortality compared with heparin 5000 U/mL. In summary, antibiotics plus low-dose heparin was ranked as the best lock solution. The overall results were not materially changed in sensitivity analyses.

CONCLUSIONS

Taking into account both efficacy and safety, antibiotics plus low-dose heparin (500-2500 U/mL) may be the preferred lock solution.

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.

Efficacy of urokinase lock to treat thrombotic dysfunction of tunneled hemodialysis catheters: A retrospective cohort study

BACKGROUND:

There are few data to inform decisions about the optimal management of occluded tunneled cuffed hemodialysis catheters with thrombolytic locking solutions. The effect of dose, dwell-time, and number of administrations remains controversial.

METHODS:

In this retrospective single-center review of tunneled cuffed catheters used between 2010 and 2014, restoration of blood flow as well as pre- and post-pump pressures after either short (30 min) or prolonged (48-72 h) administration of 100,000 IU of urokinase locking solution was evaluated in all thrombotic dysfunctions. We also assessed if multiple urokinase locks for the same thrombotic dysfunction event were more efficient to restore catheter performance than single administration.

RESULTS:

Data on 773 thrombotic events in 148 patients (236 catheters) were collected during observation period. After urokinase treatment, blood flow and pre-pump pressure improved (median of 50 mL/min and 20 mmHg) whereas post-pump pressure decreased (median of 15 mmHg) (all P < 0.0001). The short thrombolytic procedure, used in more severely dysfunctional catheters, resulted in significantly larger improvements in catheter function than the long procedure. Multiple administrations for the same thrombotic event further improved access function in case of persisting dysfunction after first lock but had no added beneficial effect if blood flow and/or pump pressures were normalized after first urokinase lock.

CONCLUSION:

Both short and prolonged administration of urokinase locks were efficient in restoring blood flow and pre- and post-pump pressures in dialysis catheters with thrombotic dysfunction. Multiple urokinase locks provide added benefit on these outcomes only in case of persisting dysfunction after the first lock.

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.

Microstructural evaluation by confocal and electron microscopy in thrombi developed in central venous catheters

Abstract OBJECTIVE Evaluating thrombi microstructure developed in central venous catheters using confocal and electron microscopy. METHOD An experimental, descriptive study carrying out a microstructural evaluation of venous thrombi developed in central venous catheters using Scanning Electron Microscopy and Confocal Laser Scanning Microscopy. RESULTS A total of 78 venous catheters were collected over a period of three months. Different fibrin structures were distinguished: fibrin plates, fibrin network, and fibrin fibers. It was observed that the thrombus had thick fibrin plates adhered to the catheter wall openings in both a catheter with three days of permanence as well as in a catheter with 20 days of insertion in the patient. However, a greater amount of erythrocytes and fibrin fibers were found in the central region of the thrombus. CONCLUSION This study contributes to improving health care and can have a positive impact on clinical practice, as easy adherence of platelets and fibrins to the catheter wall demonstrated in this study makes it possible to adopt thrombus prevention strategies such as therapy discontinuation for an extended period, blood reflux by a catheter, slow infusion rate and hypercoagulo pathyclinical conditions.

Urokinase-containing locking solution in the prevention of dialysis catheter dysfunction: a double blind randomized controlled trial

INTRODUCTION

The prophylactic use of recombinant tissue plasminogen activator once weekly reduces the incidence rate of tunneled cuffed catheter (TCC) malfunction and bacteremia as compared to the exclusive use of heparin as locking solution. Restricting the use of prophylactic thrombolytic agents to patients with a history of thrombotic TCC malfunction could be more cost effective. We conduct a multicenter, double-blind, randomized controlled trial and test the hypothesis that weekly use of urokinase lock will reduce the incidence of thrombotic malfunction by 50% in prevalent hemodialysis patients with a history of thrombotic malfunction.

METHODS

Patients with a history of at least two separate TCC thrombotic dysfunctions treated with urokinase lock during the 6 months preceding inclusion are recruited in eight Belgian dialysis units. Patients are randomized in two groups: the control group receiving Taurolock™-HEP500 (heparin 500 IU/mL, taurolidine, citrate 4%) after each hemodialysis session and the treatment group receiving Taurolock-U 25,000 (urokinase 25,000, taurolidine, citrate 4%) once a week and the standard Taurolock-HEP500 at the end of the two others sessions. The primary outcome is the incidence rate of TCC thrombotic dysfunction defined by the use of urokinase. The secondary outcomes are the incidence rate of TCC removal and systemic thrombolysis. For the study, both patients and healthcare staff are blinded to treatment allocation.

CONCLUSIONS

The present trial is the first to investigate the effect of Taurolock-U 25,000 catheter lock once a week as secondary prevention in hemodialysis patients with the highest risk of TCC-related thrombotic dysfunction.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02036255.

Vascular Access for Placement of Tunneled Dialysis Catheters for Hemodialysis: A Systematic Approach and Clinical Practice Algorithm

The role of interventional radiology in the overall management of patients on dialysis continues to expand. In patients with end-stage renal disease (ESRD), the use of tunneled dialysis catheters (TDCs) for hemodialysis has become an integral component of treatment plans. Unfortunately, long-term use of TDCs often leads to infections, acute occlusions, and chronic venous stenosis, depletion of the patient's conventional access routes, and prevention of their recanalization. In such situations, the progressive loss of venous access sites prompts a systematic approach to alternative sites to maximize patient survival and minimize complications. In this review, we discuss the advantages and disadvantages of each vascular access option. We illustrate the procedures with case histories and images from our own experience at a highly active dialysis and transplant center. We rank each vascular access option and classify them into tiers based on their relative degrees of effectiveness. The conventional approaches are the most preferred, followed by alternative approaches and finally the salvage approaches. It is our intent to have this review serve as a concise and informative reference for physicians managing patients who need vascular access for hemodialysis.

Hemodialysis catheter thrombi: visualization and quantification of microstructures and cellular composition

PURPOSE

Despite the increasing use of central venous catheters (CVC) for hemodialysis in clinical practice, the role of CVC in thrombus development is poorly understood. This work aims at defining new methods and protocols for assessing the micromorphology and composition of thrombi formed into tunneled and non-tunneled hemodialysis CVC removed from patients. 


METHODS

Twenty-nine CVCs were collected and the microscopic features of intra-luminal thrombi were quantified by scanning electron microscopy (SEM) and visualized by two photon laser scanning microscopy (TPLSM). 


RESULTS

SEM quantification showed that fibrin was the most abundant structure in CVC thrombi. Specifically, the median micromorphologic composition of the surface layer resulted in: 42.6% of fibrin plaque, 16.3% of fibrin network, 0.4% of fibrin fibers, 9.3% of platelets, 10.3% of erythrocytes and 1.7% of white blood cells. TPLSM showed that sub-surface layers were instead composed by smaller amounts of fibrin and platelets and higher amounts of blood cells.


CONCLUSIONS

Integration of SEM and TPLSM was found to be an excellent tool for characterizing thrombi in hemodialysis CVC removed from patients. Protocols and techniques presented here may be useful in the development and testing of new strategies for limiting thrombus formation on vascular access because of CVC.