A Prospective Comparison of Two Types of Tunneled Hemodialysis Catheters: The Ash Split Versus the PermCath

Tunneled Hemodialysis Catheter Tip Design and Risk of Catheter Dysfunction: An Australian Nationwide Cohort Study

RATIONALE & OBJECTIVE

Hemodialysis catheter dysfunction is an important problem for patients with kidney failure. The optimal design of the tunneled catheter tip is unknown. This study evaluated the association of catheter tip design with the duration of catheter function.

STUDY DESIGN

Observational cohort study using data from the nationwide REDUCCTION trial.

SETTING & PARTICIPANTS

4,722 adults who each received hemodialysis via 1 or more tunneled central venous catheters in 37 Australian nephrology services from December 2016 to March 2020.

EXPOSURE

Design of tunneled hemodialysis catheter tip, classified as symmetrical, step, or split.

OUTCOME

Time to catheter dysfunction requiring removal due to inadequate dialysis blood flow assessed by the treating clinician.

ANALYTICAL APPROACH

Mixed, 3-level accelerated failure time model, assuming a log-normal survival distribution. Secular trends, the intervention, and baseline differences in service, patient, and catheter factors were included in the adjusted model. In a sensitivity analysis, survival times and proportional hazards were compared among participants' first tunneled catheters.

RESULTS

Among the study group, 355 of 3,871 (9.2%), 262 of 1,888 (13.9%), and 38 of 455 (8.4%) tunneled catheters with symmetrical, step, and split tip designs, respectively, required removal due to dysfunction. Step tip catheters required removal for dysfunction at a rate 53% faster than symmetrical tip catheters (adjusted time ratio, 0.47 [95% CI, 0.33-0.67) and 76% faster than split tip catheters (adjusted time ratio, 0.24 [95% CI, 0.11-0.51) in the adjusted accelerated failure time models. Only symmetrical tip catheters had performance superior to step tip catheters in unadjusted and sensitivity analyses. Split tip catheters were infrequently used and had risks of dysfunction similar to symmetrical tip catheters. The cumulative incidence of other complications requiring catheter removal, routine removal, and death before removal were similar across the 3 tip designs.

LIMITATIONS

Tip design was not randomized.

CONCLUSIONS

Symmetrical and split tip catheters had a lower risk of catheter dysfunction requiring removal than step tip catheters.

FUNDING

Grants from government (Queensland Health, Safer Care Victoria, Medical Research Future Fund, National Health and Medical Research Council, Australia), academic (Monash University), and not-for-profit (ANZDATA Registry, Kidney Health Australia) sources.

TRIAL REGISTRATION

Registered at ANZCTR with study number ACTRN12616000830493.

PLAIN-LANGUAGE SUMMARY

Central venous catheters are widely used to facilitate vascular access for life-sustaining hemodialysis treatments but often fail due to blood clots or other mechanical problems that impede blood flow. A range of adaptations to the design of tunneled hemodialysis catheters have been developed, but it is unclear which designs have the greatest longevity. We analyzed data from an Australian nationwide cohort of patients who received hemodialysis via a tunneled catheter and found that catheters with a step tip design failed more quickly than those with a symmetrical tip. Split tip catheters performed well but were infrequently used and require further study. Use of symmetrical rather than step tip hemodialysis catheters may reduce mechanical failures and unnecessary procedures for patients.

Comparative effectiveness and safety among different tip-design hemodialysis long-term catheters: A meta-analysis

PURPOSE

The aim of this meta-analysis is to compare effectiveness and safety among different tip-design long-term hemodialysis (HD) catheters.

MATERIALS AND METHODS

PubMed, Embase, and Cochrane Library databases were searched until 8 December 2021 to identify randomized controlled trials (RCTs) and cohort studies comparing step-tip, split-tip, or symmetrical-tip design catheters in patients undergoing HD will be included. The Cochrane Risk of Bias tool and the Newcastle-Ottawa Scale were used to evaluate the quality of RCTs and cohort studies. Data extracted from the articles were integrated to determine mean effective blood pump velocity (Qb), blood recirculation rates, secondary patency, catheter-related infection, catheter-related blood stream infection (CRBSI), thrombosis rates, and all-cause mortality for the three tip-designs. We performed meta-analysis on dichotomous outcomes using a random-effects model to evaluate risk ratios (RRs) and 95% confidence intervals (Cls). The effect sizes of continuous outcomes were reported as the mean difference (MD). Sensitivity and subgroup analyses were also performed. The study was registered in the PROSPERO (CRD42021297069).

RESULTS

Six RCTs and 11 cohort studies of 2617 individuals were included in our meta-analysis, of which 1088 individuals inserted split-tip catheters, 897 individuals inserted step-tip catheters and 650 received symmetrical-tip design catheters. Sym-tip performed better in mean Qb (MD = 43.85, 95% Cl = 18.13-69.56, p = 0.0008) than step-tip. Split-tip had better outcomes vs step-tip in blood recirculation (RR = 3.44, 95% Cl = 2.49-4.39, p < 0.00001). Sym-tip had significantly better outcomes compared with step-tip (RR = 0.28, 95%Cl = 0.09-0.81, Z = 2.34, p = 0.02) and split-tip (RR = 0.19, 95% Cl = 0.09-0.43, p < 0.0001) in thrombotic events. No significant difference was found in secondary patency, infection rates, CRBSI, and all-cause mortality among the three tip-designs.

CONCLUSION

The sym-tip of tunneled cuffed catheters performed better mean Qb, lower thrombotic events, and lower blood recirculation when blood line reversed, which may have an advantage over other two catheter-tips.

Factors influencing the long-term outcome of tunneled hemodialysis catheters

PURPOSE

To review the incidence and type of tunneled hemodialysis catheter (THC) complications in a large cohort of patients with end-stage renal disease. Additionally, the longevity of the THC and factors predicting high risk for catheter complications were assessed.

MATERIAL AND METHODS

Between August 2009 and December 2016, a cohort of 538 patients underwent primary THC insertion; in 119 patients, THC was inserted after failed arteriovenous fistula or graft. Patients without available clinical follow-up data (n = 67) were excluded for further analysis. The Charlson comorbidity index (CCI) was calculated for each patient. The cumulative incidence function (CIF) was used for THC overall longevity, while Cox proportional hazards models were used for risk factor analysis.

RESULTS

In 352 patients, THC was inserted in a virgin neck. THC-related complications were observed in n = 104 (29.55%) of the patients. Infection occurred in n = 38 (10.80%) and malfunction, related to thrombosis or mechanical damage, in n = 45 (12.78%). Removal of the THC for the purpose of switching to alternative dialysis methods was planned in n = 135 (38.4%). The remaining patients were still alive with a functioning THC (n = 18; 5.11%) or died (n = 95; 27%) with a functioning THC. The THC survival rate was 82.67%, 78.13%, 74.15%, 72.96%, 71.02%, and 70.63% on follow-up after 6 months, and after 1-5 years, respectively. Gender, CCI, age, and site of placement of the catheter were found not to affect the life of the catheter.

CONCLUSION

The overall complication rate in primary inserted THC was nearly 30% and mainly related to infection and malfunction. THC survival was more than 70% after 5 years, which supports its use for permanent dialysis access, irrespective of gender, CCI, age, and jugular side of THC placement.

Dialysis Vascular Access: Where do Tunneled Catheters Stand? - A Single-Center Experience

Introduction

Tunneled cuffed catheters (TCC) provides a short and intermediate-term access solution for dialysis patients who fail to get an arteriovenous fistula (AVF). They are associated with high morbidity and mortality along with high rates of infectious complications.

Methods

We present a single-center prospective cohort of 159 TCCs inserted over one year. Patients were dialyzed in-hospital and in various peripheral dialysis units attached to the institute. The primary endpoint was catheter drop-out.

Results

The mean age of patients was 41.8 ± 16.9 years. The right internal jugular vein was the commonest site of TCC insertion (66%). The absence of suitable veins was the predominant reason for TCC insertion. The mean time to catheter drop-out was 134.4 ± 83.3 days (5-399 days). Death with a working catheter was the most common cause of catheter drop-out (22.6%). About 25% of catheters were lost to catheter-related bloodstream infections (CRBSI), either alone or as overlap with poor flow. CRBSI rates were 3.74 episodes per 1000 catheter-days. No difference in survival between the staggered tip and split-tip catheters was found.

Conclusions

With the advent of the "hub and spoke" model for dialysis in the public sector healthcare, TCCs are suboptimal with regards to patient and catheter survival, with high infection rates. It must be regarded as a temporary solution and AVF creation should be prioritized.

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.

Catheter type, placement and insertion techniques for preventing catheter-related infections in chronic peritoneal dialysis patients

BACKGROUND

Peritonitis is one of the limiting factors for the growth of peritoneal dialysis (PD) worldwide and is a major cause of technique failure. Several studies have examined the effectiveness of various catheter-related interventions for lowering the risk of PD-related peritonitis. This is an update of a review first published in 2004.

OBJECTIVES

To evaluate the role of different catheter implantation techniques and catheter types in lowering the risk of PD-related peritonitis in PD patients.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 15 January 2019 through contact with the Information Specialist using search terms relevant to this review. Studies in the 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

Studies comparing different catheter insertion techniques, catheter types, use of immobilisation techniques and different break-in periods were included. Studies of different PD sets were excluded.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study quality and extracted data. Statistical analyses were performed using a random effects model and the results expressed as risk ratio (RR) with 95% confidence intervals (CI).

MAIN RESULTS

Forty-two studies (3144 participants) were included: 18 evaluated techniques of catheter implantation, 22 examined catheter types, one assessed an immobiliser device, and one examined break-in period. In general, study quality was variable and almost all aspects of study design did not fulfil CONSORT standards for reporting.Catheter insertion by laparoscopy compared with laparotomy probably makes little or no difference to the risks of peritonitis (RR 0.90, 95% CI 0.59 to 1.35; moderate certainty evidence), exit-site/tunnel infection (RR 1.00, 95% CI 0.43 to 2.31; low certainty evidence), catheter removal/replacement (RR 1.20, 95% CI 0.77 to 1.86; low certainty evidence), technique failure (RR 0.71, 95% CI 0.47 to 1.08; low certainty evidence), and death (all causes) (RR 1.26, 95% CI 0.72 to 2.20; moderate certainty evidence). It is uncertain whether subcutaneous burying of catheter increases peritonitis (RR 1.16, 95% CI 0.37 to 3.60; very low certainty evidence). Midline insertion compared to lateral insertion probably makes little or no difference to the risks of peritonitis (RR 0.65, 95% CI 0.32 to 1.33; moderate certainty evidence) and may make little or no difference to exit-site/tunnel infection (RR 0.56, 95% CI 0.12 to 2.58; low certainty evidence). Percutaneous insertion compared with open surgery probably makes little or no difference to the exit-site/tunnel infection (RR 0.16, 95% CI 0.02 to 1.30; moderate certainty evidence).Straight catheters probably make little or no difference to the risk of peritonitis (RR 1.04, 95% CI 0.82 to 1.31; moderate certainty evidence), peritonitis rate (RR 0.91, 95% CI 0.68 to 1.21; moderate certainty evidence), risk of exit-site infection (RR 1.12, 95% CI 0.94 to 1.34; moderate certainty evidence), and exit-site infection rate (RR 1.05, 95% CI 0.77 to 1.43; moderate certainty evidence) compared to coiled catheter. It is uncertain whether straight catheters prevent catheter removal or replacement (RR 1.11, 95% CI 0.73 to 1.66; very low certainty evidence) but straight catheters probably make little or no difference to technique failure (RR 0.82, 95% CI 0.51 to 1.31; moderate certainty evidence) and death (all causes) (RR 0.95, 95% CI 0.62 to 1.46; low certainty evidence) compared to coiled catheter. Tenckhoff catheter with artificial curve at subcutaneous tract compared with swan-neck catheter may make little or no difference to peritonitis (RR 1.29, 95% CI 0.85 to 1.96; low certainty evidence) and incidence of exit-site/tunnel infection (RR 0.96, 95% CI 0.77 to 1.21; low certainty evidence) but may slightly improve exit-site infection rate (RR 0.67, 95% CI 0.50 to 0.90; low certainty evidence).

AUTHORS' CONCLUSIONS

There is no strong evidence that any catheter-related intervention, including the use of different catheter types or different insertion techniques, reduces the risks of PD peritonitis or other PD-related infections, technique failure or death (all causes). However, the numbers and sizes of studies were generally small and the methodological quality of available studies was suboptimal, such that the possibility that a particular catheter-related intervention might have a beneficial effect cannot be completely ruled out with confidence.

Precurved non-tunnelled catheters for haemodialysis are comparable in terms of infections and malfunction as compared to tunnelled catheters: A retrospective cohort study

Background:

The main limitations of central venous catheters for haemodialysis access are infections and catheter malfunction. Our objective was to assess whether precurved non-tunnelled central venous catheters are comparable to tunnelled central venous catheters in terms of infection and catheter malfunction and to assess whether precurved non-tunnelled catheters are superior to straight catheters.

Materials and methods:

In this retrospective, observational cohort study, adult patients in whom a central venous catheter for haemodialysis was inserted between 2012 and 2016 were included. The primary endpoint was a combined endpoint consisting of the first occurrence of either an infection or catheter malfunction. The secondary endpoint was a combined endpoint of the removal of the central venous catheter due to either an infection or a catheter malfunction. Using multivariable analysis, cause-specific hazard ratios for endpoints were calculated for tunnelled catheter versus precurved non-tunnelled catheter, tunnelled catheter versus non-tunnelled catheter, and precurved versus straight non-tunnelled catheter.

Results:

A total of 1603 patients were included. No difference in reaching the primary endpoint was seen between tunnelled catheters, compared to precurved non-tunnelled catheters (hazard ratio, 0.91; 95% confidence interval, 0.70–1.19, p = 0.48). Tunnelled catheters were removed less often, compared to precurved non-tunnelled catheters (hazard ratio, 0.65; 95% confidence interval, 0.46–0.93; p = 0.02). A trend for less infections and catheter malfunctions was seen in precurved jugular non-tunnelled catheters compared to straight non-tunnelled catheters (hazard ratio, 0.60; 95% confidence interval, 0.24–1.50; p = 0.28) and were removed less often (hazard ratio, 0.41; 95% confidence interval, 0.18–0.93; p = 0.03).

Conclusion:

Tunnelled central venous catheters and precurved non-tunnelled central venous catheters showed no difference in reaching the combined endpoint of catheter-related infections and catheter malfunction. Tunnelled catheters get removed less often because of infection/malfunction than precurved non-tunnelled catheters.

ACR Appropriateness Criteria® Radiologic Management of Central Venous Access

Obtaining central venous access is one of the most commonly performed procedures in hospital settings. Multiple devices such as peripherally inserted central venous catheters, tunneled central venous catheters (eg, Hohn catheter, Hickman catheter, C. R. Bard, Inc, Salt Lake City UT), and implantable ports are available for this purpose. The device selected for central venous access depends on the clinical indication, duration of the treatment, and associated comorbidities. It is important for health care providers to familiarize themselves with the types of central venous catheters available, including information about their indications, contraindications, and potential complications, especially the management of catheters in the setting of catheter-related bloodstream infections. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

The Vascular Access Questionnaire: Assessing Patient-Reported Views of Vascular Access

Background

The use of central venous catheters for vascular access in hemodialysis (HD) patients is associated with an increased risk of complications compared to arteriovenous fistulas (AVF). Despite this, catheter use remains high and patient satisfaction may be an important driver of catheter use.

Methods

We developed the Vascular Access Questionnaire (VAQ) to measure patient-reported views of their vascular access. Chronic HD patients at two centers were asked to rate how bothered they were by 17 access-related problems. VAQ symptom scores were compared between patients using catheters and those using fistulas for vascular access.

Results

Two hundred and twenty-two patients were eligible for the study. Symptom score was not different between patients using catheters and those using fistulas (p=0.36). However, patients using fistulas were more likely to be at least moderately bothered by pain, bleeding, bruising, swelling, and the appearance of their access than patients using catheters. Elderly patients reported lower symptom scores with catheters than fistulas.

Conclusions

Patients appear to be primarily concerned with the appearance of their access and cannulation-related complications, particularly the elderly. Better education about the risk of adverse events with catheters and the implementation of measures aimed at reducing cannulation-related complications may help to increase fistula rates and improve patient satisfaction with their vascular access.

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.

A prospective comparison of the performance and survival of two different tunnelled haemodialysis catheters: SplitCath® versus DuraMax®

BACKGROUND

Despite their well-recognised shortcomings, haemodialysis catheters (HDCs) remain an important form of haemodialysis access for many patients. There are several HDCs commercially available, each differing considerably in design, which is known to significantly influence performance and survival. We sought to determine which of two tunnelled HDCs, DuraMax® (Angiodynamics, NY, USA) or SplitCath® (MedComp, PA, USA) delivers the best performance, safety and reliability for dialysis patients.

METHODS

Eighty-six patients were prospectively randomised to receive either DuraMax® (DM) or SplitCath® (SC). Outcomes included: (i) mean flow rates (mL/min) averaged over the first 10 weeks of dialysis, and urea reduction ratio (URR); and (ii) long-term catheter survival with appraisal of any events leading to catheter dysfunction and early removal.

RESULTS

Median flow rates (interquartile range) in the DM and SC groups were 321 (309-343) and 309 (294-322) mL/min, respectively (p = 0.002). URR values for the DM and SC groups were 71 (65-76) and 74 (70-78), respectively, (p = 0.094). There was no significant difference in long-term survival or frequency of incidents that required early HDC removal (9/43 in the DM group, 5/43 patients SC). A slightly higher incidence of HDC dislodgement was noted in the DM group, although this study was not statistically powered to determine its significance.

CONCLUSIONS

We conclude that DM yields slightly higher flow rates in the first 10 weeks of dialysis, and a similar low incidence of complications and long-term survival for both DM and SC HDCs.

Comparison of Tesio and LifeCath Twin Permanent Hemodialysis Catheters: The VyTes Randomized Trial

Purpose

Central venous catheters for maintenance hemodialysis (HD) are designed to attain the required dialysis dose through sustained high blood flow rates (BFR). The authors studied the immediate and long-term performance and complications of two twin-catheter systems, the Tesio catheter (TC) and the LifeCath Twin (LC), to inform clinical practice.

Methods

This single-center randomized controlled parallel-group trial allocated 80 incident patients (1:1) to receive either a TC (MedComp) or LC (Vygon). Patients were dialyzed to target BFR 450 mL/min and followed up for 12 months. The primary outcome was achievement of target BFR during the first HD session. Secondary outcomes included thrombotic dysfunction, displacement and catheter-related infection. Catheter dysfunction was defined by a BFR ≤ 250 mL/min.

Results

More LCs reached the primary endpoint (44% vs. 10%, p=0.001) delivering a higher BFR (mean 383±82 vs. 277±79 mL/min, p<0.001). Significant differences in BFR persisted until the fourth dialysis session. Rates of catheter-related bacteremia (0.40 vs. 0.51/1,000 catheter days, p=0.7) and exit site infection were similar between groups (0.24 vs. 0.09/1,000 catheter days, p=0.4). Overall rates of catheter dysfunction were 2.8/1,000 catheter days (95% CI 2.1-3.5), with no differences in thrombolytic lock use although the LC group required more thrombolytic infusions (6 vs. 0, p=0.01).

Conclusions

The LC can deliver greater BFRs in the first three HD sessions following insertion although this did not translate into differences in performance, dialysis adequacy or complication rates with long-term use. Both catheter types can consistently deliver high BFRs over an extended period of time.

[Central venous catheters as access for acute and long-term dialysis]

Central venous dialysis catheters are indispensible as a rapid large lumen access to the blood compartment. If such a central venous catheter is necessary for longer than 2-3 weeks it is better to implant a tunnelled cuffed catheter initially or to switch early from the non-tunnelled acute catheter to a tunnelled cuffed catheter. Tunnelled cuffed catheters can be used for many weeks or even years and the complication rate is less than that of non-tunnelled acute catheters. The proportion of dialysis patients with long-term dialysis using tunnelled cuffed catheters has increased rapidly in recent years and now stands at approximately 20 % in Germany. These catheters are, however, prone to more infectious complications and more thromboses than native arteriovenous fistulas or prosthetic shunts. The mortality of patients with long-term dialysis catheters is also higher than those with arteriovenous shunts. For these reasons central venous catheters will always be regarded as the third choice dialysis access when arteriovenous fistulas are not possible. Catheters are available in a wide variety of designs but the individual advantages are still unclear. In order to avoid short-term and long-term complications a variety of measures for implantation and use during dialysis treatment have been developed which make the use safer.

[Tunneled hemodialysis catheters complications: a retrospective and monocentric comparative study of two devices]

PURPOSE

In a monocentric retrospective study, two tunneled hemodialysis catheters have been compared: a twin cylinder catheter (Dualcath) and a split tip catheter (Hemosplit).

PATIENTS AND METHODS

Patients who got catheters from January 1st 2007 to December 31st 2008 have been selected. Thrombotic events, as well as infectious events, were recorded in their dialysis file during this period of time.

MAIN RESULTS

The study was carried out on 50 patients. Thirty of them were given Dualcath, 23 were given Hemosplit, and three both of them. A Kaplan-Meier analysis has enabled to draw up the catheter survival curves, and the log-rank test enables to establish a survival of 93.1% at 20 months for Dualcath while 42.2% for Hemosplit. As far as the thrombotic complications with catheter incident are concerned, their incidence is 25.5 and 46.4 out of 1000 catheter-days (P<0,0001). The ones with catheter manipulation have incidences of 6.78 and 9.33 out of 1000 catheter-days, respectively for Dualcath and Hemosplit (NS). Dualcath presents catheter-related infections with a rate of 4.38 out of 1000-catheter days while 5.07 for Hemosplit (NS).

CONCLUSION

The Dualcath catheter presents a better survival than the Hemosplit catheter as well as weaker incident type thrombotic complications.

Tunneled central venous catheters: Experience from a single center

In the past vascular surgeons were called in to place tunneled central venous catheter (TVC) for hemodialysis patients. Advent of percutaneous technique has resulted in an increasing number of interventional nephrologists inserting it. A single centre three year audit of 100 TVCs with a cumulative follow up of 492 patient months is presented here. From 2007 to 2010, 100 TVCs were placed by nephrologists in a percutaneous fashion in the operative room or the interventional nephrology suite. Those who completed minimum of three months on the catheter were included in analysis. There were 69 males and 31 females with a mean age of 52.3±13.6 years.(range: 25-76). Chronic glomerulonephritis was the commonest cause of CKD (45%) followed by diabetes (39%).Right internal jugular vein was the preferred site (94%). TVC was utilized as the primary access to initiate dialysis in 25% of patients in whom a live donor was available for renal transplant. The blood flow was 250-270 ml/min. The Kaplan-Meier analysis showed that 3 months and 6 months catheter survival rates were 80% and 55%, respectively. The main complications were exit site blood ooze, catheter block and kink. Catheter related bacteremia rate was low at 0.4/1000 patient days. Primary cause of drop out was patient death unrelated to the TVCs. Those under the age of 40 years showed better survival, but there was no bearing of gender, catheter site, and etiology of CKD on survival. Tunneled central venous catheters could find a niche as the primary access of choice for pretransplant live donor renal transplants in view of its immediate usage, high blood flows, low infection rates and adequate patency rates for 3-6 months.

Large-bore tunneled central venous catheter insertion in patients with coagulopathy

PURPOSE

To evaluate the safety of tunneled central venous catheter (TCVC) insertion in patients with an International Normalized Ratio (INR) of greater than or equal to 1.5 or a platelet count lower than 50,000/dL.

MATERIALS AND METHODS

Our division's criteria for acceptable coagulation parameters in patients undergoing TCVC insertion is INR no greater than 2 and platelet count of at least 25,000/dL. Three-thousand one-hundred and eighty-eight TCVCs (8-14.5 F) placed between July 2001 and July 2008 were identified. After excluding incomplete records, 2,514 patients undergoing 3,170 TCVC placements were identified. The most current platelet count and INR at the time of TCVC insertion were identified. Bleeding complications were compared between patients with platelet counts lower than 50,000/dL and/or INR of at least 1.5 and published standards for complication rates for TCVC insertion.

RESULTS

Of the total of 3,170 TCVCs placed, 428 were in patients whose most current platelet count was lower than 50,000/dL and 361 were in patients with an INR of 1.5 or greater. After exclusion of intercurrent blood product transfusion, 626 TCVCs placed in 567 patients with a platelet count lower than 50,000/dL and/or an INR of at least 1.5 were identified. There were 27 complications in the entire study population (0.85%); three were in patients with platelet counts lower than 50,000/dL and/or INR of at least 1.5. There were three bleeding complications in the study population (0.095%), none in patients with platelet count lower than 50,000/dL and/or INR of at least 1.5.

CONCLUSIONS

Placement of TCVCs in patients with a platelet count between 25,000/dL and 50,000/dL and/or an INR between 1.5 and 2 is safe even without coagulation product transfusions.

Do AshSplit haemodialysis catheters provide better flow rates in the long term?

BACKGROUND

Recently, interventional radiologists have adopted an increasingly prominent role in the placement and management of hemodialysis catheters, as well as in the research and development of new and better catheters. The purpose of this study was to evaluate the viability and hemodialysis efficiency of the AshSplit catheter and the Permcath catheter.

METHODS

204 consecutive patients requiring radiological insertion of hemodialysis catheters were followed, retrospectively, over a 42-month period. Both hemodialysis catheters were placed using a combination of ultrasonic and fluoroscopic guidance and tunneled appropriately. Information collected included catheter insertion sites, insertion complications, catheter duration, and final outcome.

RESULTS

Over the study period of two years, 269 catheters were placed into 204 patients with end stage renal failure. Patients received either an AshSplit (101 patients, 127 catheters) or a Permcath (103 patients, 142 catheters). Vascular access route of choice was the right internal jugular vein (67% AshSplit, 71% Permcath). Insertion complications occurred in 18 patients overall (6.6%), with only 1 requiring further intervention (hemopneumothorax). Flow rates averaged 259 mls/min for AshSplits and 248 mls/min for Permcaths (p < 0.001). Follow-up of catheter viability for 42 months yielded a mean AshSplit catheter duration of 246 days (range 6-932) and 239 days (range 1-1,278) for Permcath (p = 0.46). Reasons for catheter failure and elective catheter removal were similar in both groups; however, Permcaths required significantly more thrombolysis than AshSplits, p < 0.001.

CONCLUSION

The AshSplit provides significantly better flow rates and less thrombolysis compared to the Permcath, with similar catheter dwell times.

Bilateral duplicated internal jugular veins: Case study and literature review

A rare bilateral duplication of the internal jugular vein (IJV) was discovered during cadaveric dissection. From each jugular foramen, a single IJV descended to the level of the hyoid bone then divided into medial and lateral veins. The medial IJVs traveled in the carotid sheath; the lateral IJVs coursed posterolateral to the sheath across the lateral cervical region (posterior triangle) of the neck. On the right side, medial and lateral IJVs entered the subclavian vein separately. C2-C3 anterior rami and the suprascapular artery passed between the medial and lateral IJVs. The right external jugular vein passed aberrantly between the heads of the sternocleidomastoid muscle (SCM) into the subclavian vein anterior to the lateral IJV. On the left side, the medial IJV drained into a large bulbous jugulovertebrosubclavian (JVS) sinus that received six main vessels. The lateral IJV diverged posterolaterally toward the border of the trapezius muscle, received the transverse cervical vein, and then turned sharply anteromedially to drain into the JVS sinus. The lateral IJV also gave an aberrant additional large vein that passed laterally around the omohyoid muscle before entering the JVS sinus. The left external jugular vein paralleled the anterior border of SCM before passing posterolaterally to terminate in the JVS sinus. Jugular vein anomalies of this magnitude are very rare. Determining the frequency of multiple IJVs is hampered by inconsistent terminology. We suggest that IJV duplication differs from fenestration anatomically and, potentially, developmentally. Criteria for characterizing IJV duplication and fenestration are proposed. The mechanism of development and the clinical significance of multiple IJVs are discussed.