Treatment of Tunneled Dialysis Catheter Malfunction: Revision versus Exchange

Placement of tunnelled haemodialysis catheters-interventional standard

While the native arteriovenous fistula remains the first choice in vascular access for most haemodialysis patients, tunnelled haemodialysis catheters (tHDCs) continue to be an option in selected patients. Since timely access to vascular surgery-due to delayed referral or resource limitations-is not always possible, nephrologists have to become more actively involved in planning, creation and monitoring of vascular access. Moreover, this approach could also strengthen patient-centred care in nephrology. This article reviews the current standard in tHDC creation, patient selection and strategies to mitigate the risk of infectious complications and catheter thrombosis. Presentation of novel developments in catheter placement with ultrasound-guided or electrocardiogram-guided positioning, their benefits and possible disadvantages emphasizes the complexity of vascular access planning. We offer an approach for the choice of insertion method, depending on selected side and existing resources and focus on the necessity and required resources of 'interventional nephrology' training programs.

Replacement Strategies for Tunneled Hemodialysis Catheters with Complications: A Nationwide Cohort Study

Key Points

Replacement strategies for hemodialysis catheters with mechanical failure differed widely between services, which suggests clinical equipoise. For mechanical hemodialysis catheter failure, exchange did not result in more dysfunction or infection than removal and separate replacement. In Australia, infected catheters were almost universally removed and then replaced through a separate tunnel tract.

Background

Tunneled hemodialysis catheters often have infectious or mechanical complications that require unplanned removal and replacement, but the optimal replacement strategy is unknown. This study described the real-world use of two strategies in Australia and compared the survival of replacement catheters inserted by either strategy.

Methods

Observational data from the REDUcing the burden of dialysis Catheter ComplicaTIOns: a National approach trial, which enrolled a nationwide cohort of 6400 adults who received an incident hemodialysis catheter (2016–2020), was used for this secondary analysis. Tunneled catheters were replaced by either catheter exchange through the existing tunnel tract or removal and replacement through a new tract. The effect of the replacement strategy on the time to catheter removal because of infection or dysfunction was estimated by emulating a hypothetical pragmatic randomized trial among a subset of 434 patients with mechanical tunneled catheter failure.

Results

Of 9974 tunneled hemodialysis catheters inserted during the trial, 380 had infectious and 945 had mechanical complications that required replacement. Almost all infected hemodialysis catheters (97%) were removed and separately replaced through a new tunnel tract, whereas nephrology services differed widely in their replacement practices for catheters with mechanical failure (median=50% guidewire exchanged, interquartile range=30%–67%). Service-level differences accounted for 29% of the residual variation after adjusting for patient factors. In the target trial emulation cohort of patients with mechanical catheter failure (n =434 patients), catheter exchange was not associated with lower complication-free survival at 1, 6, or 12 months (counterfactual survival difference at 1 month=5.9%; 95% confidence interval, −2% to 14%).

Conclusions

Guidewire exchange for mechanical failure of catheter was not associated with lower catheter survival and may be preferable for patients.

Trial registration and protocol:

The trial was registered in the Australia and New Zealand clinical trials registry on the June 23, 2016 (ACTRN12616000830493).

Early identification of local infections in central venous catheters for hemodialysis: A systematic review

BACKGROUND

The use of central venous catheters (CVC) is associated with higher morbidity and mortality, related to infectious complications, contributing to poorer clinical outcomes and increased healthcare costs. According to the literature, the incidence of local infections related to CVC for hemodialysis is highly variable. This variability is related to differences in definitions of catheter-related infections.

OBJECTIVE

To identify signs and symptoms for determining local infections (exit site and tunnel tract infections) used in the literature in tunnelled and nontunnelled CVC for hemodialysis.

DESIGN

Systematic review METHODS: Structured electronic searches were conducted in five electronic databases, from 1 January 2000-31 August 2022, using key words and specific vocabulary, as well as manual searches in several journals. Additionally, vascular access clinical guidelines and infection control clinical guidelines were reviewed.

RESULTS

After validity analysis, we selected 40 studies and seven clinical guidelines. The definitions of exit site infection and tunnel infection used in the different studies were heterogeneous. Among the studies, seven (17,5 %) used the definitions of exit site and tunnel infection based on a clinical practice guideline. Three of the studies (7.5 %) used the Twardowski scale definition of exit site infection or a modification. The remaining 30 studies (75 %) used different combinations of signs and symptoms.

CONCLUSIONS

Definitions of local CVC infections are highly heterogeneous in the revised literature. It is necessary to establish a consensus regarding the definitions of hemodialysis CVC exit site and tunnel infections.

REGISTRATION

PROSPERO (CRD42022351097).

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.

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.

Effects of different catheter replacement methods on catheter service time and complications in hemodialysis patients: A cohort study

INTRODUCTION

Central venous catheter insertion for long-term vascular access is not recommended in clinical practice. However, since arteriovenous fistula creation is difficult to perform in some patients, central venous catheter insertion for long-term vascular access is performed. This study aimed to assess the complications and service time of central venous catheters replaced using different methods and to determine the influencing factors of service time.

METHODS

Study design: A retrospective observational cohort study. Setting and participants: Patients who underwent tunneled dialysis catheter malfunction (2009-2019) and had to undergo another dialysis catheter insertion were enrolled. Exposures: Ectopic replacement and in situ replacement. Outcomes: Factors such as age, sex, primary patency rate, secondary patency rate, early complications, and late complications were considered. Analytical approach: This study used a Cox proportional hazards regression model.

RESULTS

The first and the newly replaced catheter service time were 37.779 ± 24.563 months and 32.468 ± 26.638 (25) months in the ectopic group and 37.075 ± 20.550 months and 26.349 ± 22.672 months in the in situ group, respectively. In the early service time, the newly replaced catheter resulted in significant bleeding from the tunnel. The first catheter had the least complications, most adequate blood flow, and longest service time. Ectopic catheter replacement and the tip shape of the catheter were the independent factors for catheter service time. Catheter service time increased with age.

CONCLUSION

Ectopic catheter replacement can improve the primary patency rate and auxiliary primary patency rate of catheters. Ectopic catheter replacement may require sufficient surgical skills with digital subtraction angiography, resulting in a better prognosis.

Exchange over the guidewire from non-tunneled to tunneled hemodialysis catheters can be performed without patency loss

PURPOSE

The exchange from a non-tunneled hemodialysis catheter to a tunneled one over a guidewire using a previous venotomy has been reported to be safe. However, some concerns that it may increase infection risk prevent its clinical application. This approach seems particularly useful for acute kidney injury patients requiring initial renal replacement therapy, in whom we frequently worry about the choice of non-tunneled versus tunneled catheters.

MATERIALS AND METHODS

From March 2012 to February 2016, 88 cases to receive the over-the-guidewire exchange method from a non-tunneled to a tunneled catheter and 521 cases to receive de novo tunneled catheter placement from the hemodialysis vascular access cohort were compared retrospectively.

RESULTS

The immediate complication, later catheter dysfunction requiring replacement, and infection rates were comparable between the two groups. Newly placed tunneled catheter survival in the over-the-guidewire exchange group was comparable with survival in the de novo tunneled catheter group (p = 0.24). In addition, when we compared the same two methods among only intensive care unit patients; they remained similar (p = 0.19).

CONCLUSION

An exchange with the over-the-guidewire method from a non-tunneled to a tunneled catheter was comparable to a de novo catheter placement technique. Therefore, this method should be viewed more favorably and should especially be considered for acute kidney injury patients.

Optimization of Dialysis Catheter Function

Central venous catheters (CVCs) are essential in the management of hemodialysis patients, but they also carry unintended negative consequences and in particular thrombosis and infection, adversely affecting patient morbidity and mortality. This review will focus on the etiology, prevention, and management of CVC-related dysfunction, which is mainly associated with inadequate blood flow. CVC dysfunction is a major cause of inadequate depuration. Thrombus, intraluminal and extrinsic, as well as fibrous connective tissue sheath (traditionally indicated as fibrin sheath) formation play a central role in establishing CVC dysfunction. Thrombolysis with urokinase or recombinant tissue plasminogen activator (rTPA) can be undertaken in the dialysis unit, restoring adequate blood flow in most patients, preserving the existing catheter, and avoiding an interventional procedure. If thrombolytics fail, mainly because of the presence of fibrous connective tissue sheath, catheter exchange with fibrin sheath disruption may be successful and preserve the venous access site. Prevention of CVC dysfunction is important for containing costly pharmacologic and interventional treatments, which also affect patients’ quality of life. Prevention is based on the use of anticoagulant and/or thrombolytic CVC locks, which are only partially effective. Chronic oral anticoagulation with warfarin has also been proposed, but its use for this indication is controversial and its overall risk-benefit profile has not been clearly established.