Outcomes of tunneled femoral hemodialysis catheters: Comparison with internal jugular vein catheters

Case study: first implantation of a frozen, devitalized tissue-engineered vascular graft for urgent hemodialysis access

Previously we reported on the mid- to long-term follow-up in the first clinical trial to use a completely autologous tissue-engineered graft in the high pressure circulation. In these early studies, living grafts were built from autologous fibroblasts and endothelial cells obtained from small skin and vein biopsies. The graft was assembled using a technique called tissue-engineering by self-assembly (TESA), where robust conduits were grown without support from exogenous biomaterials or synthetic scaffolding. One limitation with this earlier work was the long lead times required to build the completely autologous vascular graft. Here we report the first implant of a frozen, devitalized, completely autologous Lifeline™ vascular graft. In a departure from previous studies, the entire fibroblast layer, which provides the mechanical backbone of the graft, was air-dried then stored at -80°C until shortly before implant. Five days prior to implant, the devitalized conduit was rehydrated, and its lumen was seeded with living autologous endothelial cells to provide an antithrombogenic lining. The graft was implanted as an arteriovenous shunt between the brachial artery and the axillary vein in a patient who was dependent upon a semipermanent dialysis catheter placed in the femoral vein. Eight weeks postoperatively, the graft functions without complication. This strategy of preemptive skin and vein biopsy and cold-preserving autologous tissue allows the immediate availability of an autologous arteriovenous fistula, and is an important step forward in our strategy to provide allogeneic tissue-engineered grafts available "off-the-shelf".

Does the heparin lock concentration affect hemodialysis catheter patency?

BACKGROUND AND OBJECTIVES

Concentrated heparin solutions are instilled into the catheter lumens after each hemodialysis session to prevent catheter thrombosis. The heparin lock concentration at many centers has been decreased recently to reduce the risk of systemic bleeding and contain costs. However, the effect of this change on catheter patency is unknown. We compared catheter patency between two heparin lock solutions: 1000 versus 5000 units/ml.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

With use of a prospective, computerized, vascular access database, 105 patients with newly placed tunneled hemodialysis catheters, including 58 patients receiving a 5000 units/ml heparin lock and 47 patients receiving a 1000 units/ml heparin lock, were retrospectively identified. The primary endpoint was cumulative catheter patency and the secondary endpoint was frequency of thrombolytic instillation.

RESULTS

Cumulative catheter survival was similar in the two groups, being 71% versus 73% at 120 days in the low- and high-concentration heparin lock groups (hazard ratio of catheter failure, 0.97; 95% confidence interval, 0.45 to 2.09; P = 0.95). The frequency of tissue plasminogen activator instillation was significantly greater in the low-concentration heparin group (hazard ratio, 2.18; 95% CI, 1.26 to 3.86; P = 0.005). No major bleeding complications were observed in either treatment group. The overall drug cost for maintaining catheter patency was 23% lower with the low-concentration heparin lock ($1418 versus $1917) to maintain catheter patency for 1000 days.

CONCLUSIONS

Low-concentration heparin lock solutions do not decrease cumulative dialysis catheter patency, but require a twofold increase in thrombolytic instillation to maintain long-term patency.

Thigh grafts contribute significantly to patients' time on dialysis

BACKGROUND AND OBJECTIVES

Thigh grafts are placed in hemodialysis patients who have exhausted all arm access sites. The goal of this study was to compare the survival, complication rates, and overall contribution of thigh grafts with arm grafts and fistulas in patients with at least one functional thigh graft during their dialysis history.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This longitudinal review of a prospectively acquired clinical database included 85 thigh graft recipients. The rates of survival, thrombosis, infection, and other complications were determined for a total of 268 fistulas, arm grafts, and thigh grafts placed in these patients.

RESULTS

In this patient subset, thigh graft primary failure rate was lower than arm grafts and fistulas (3 versus 13 and 61%, respectively). Excluding primary failures, thigh grafts survived longer than both arm grafts and mature fistulas (53 versus 14 and 32%, at 3 years; 47 versus 3 and 11% at 5 years). Thigh grafts had a lower thrombosis rate than arm grafts (0.543 versus 1.457/patient-year) but similar rates of loss as a result of infection and surgical revision. In patients with previous arm accesses, thigh grafts contributed 51% of total dialysis time compared with 38 and 11% for arm grafts and fistulas.

CONCLUSIONS

Thigh grafts provide long-term, thrombosis- and infection-free dialysis access for patients with exhausted arm access sites. The decision for thigh graft placement should, therefore, be made as soon as there is evidence for unavailability of arm access sites so that catheter use can be minimized.

Catheter dysfunction and dialysis performance according to vascular access among 736 critically ill adults requiring renal replacement therapy: a randomized controlled study

OBJECTIVE

To compare dialysis catheter function according to catheter site.

DESIGN

Multicenter, open, randomized controlled trial.

SETTING

Nine university-affiliated hospitals and three general hospitals in France.

PATIENTS

Seven hundred thirty-six patients in intensive care units who required a first venous catheterization to perform either intermittent hemodialysis (470 patients with 1275 sessions) or continuous renal replacement therapy (266 patients with 1003 days).

INTERVENTION

Patients randomly received either femoral (n = 370) or jugular (n = 366) catheterization. For the jugular site, right-side position (n = 252) was recommended.

MEASUREMENTS AND MAIN RESULTS

Time to catheter ablation for dysfunction, urea reduction ratio (intermittent hemodialysis), and downtime (continuous renal replacement therapy) were assessed for all participants and evaluated by randomly assigned catheterization site (femoral or jugular). Baseline demography and dialysis prescriptions were similar between the site arms. In modified intent-to-treat, catheter dysfunction occurred in 36 of 348 (10.3%) and 38 of 342 (11.1%) patients in the femoral and jugular groups, respectively. The risk of catheter dysfunction did not significantly differ between randomized groups (hazard ratio, 1.06; 95% confidence interval, 0.67-1.68; p = .80). Compared to the femoral site, the observed risk of dysfunction decreased in the right jugular position (15 of 226; 6.6%; adjusted hazard ratio, 0.58; 95% confidence interval, 0.31-1.07; p = .09) and significantly increased in the left jugular position (23 of 118; 19.5%; adjusted hazard ratio, 1.89; 95% confidence interval, 1.12-3.21; p < .02). The postintermittent hemodialysis mean urea reduction ratio per session was 50.8% (standard deviation, 16.1) for femoral vs. 52.8% (standard deviation, 15.8) for jugular (p = .30) sites, and the median continuous renal replacement therapy downtime per patient-day was 1.17 hrs (interquartile range, 0.75-1.50) for both sites (p = .98).

CONCLUSIONS

In terms of catheter dysfunction and dialysis performance among critically ill adults requiring acute renal replacement therapy, jugular site did not significantly outperform femoral site placement.

Translumbar central venous catheters for long-term haemodialysis

BACKGROUND

Vascular access for haemodialysis is achieved by tunnelled central venous catheter (CVC) in at least 23% of prevalent patients in the UK, Canada and the USA. Use of CVCs is associated with an increased incidence of venous stenosis that can progressively limit future vascular access routes. Lack of conventional venous access routes mandates the use of alternative strategies such as the translumbar approach.

METHODS

We retrospectively analysed patients at our centre requiring translumbar inferior vena caval CVCs (TesioCath) for haemodialysis in the period 1999-2008. Written and electronic records capturing dialysis adequacy and complications, hospital admissions and laboratory data were examined.

RESULTS

Thirty-nine pairs of translumbar CVCs were inserted in 26 patients with 15 864 catheter days follow-up, mean patient age 61.9 +/- 12.1 years, 31% diabetic, 15% with ischaemic heart disease. All insertions were successful. Insertion of one CVC was associated with a self-limiting retroperitoneal haematoma. No patients died of a catheter-related cause or through lack of vascular access. Cumulative assisted primary catheter site patency was 81% at 6 months and 73% at 1 year (median 18.5 months). Good dialysis adequacy was achieved throughout (mean single-pool Kt/V 1.5 +/- 0.4). The incidence of access-related infection was 2.84/1000 catheter days (exit site infection rate 2.02/1000 catheter days; catheter-related bacteraemia rate 0.82/1000 catheter days). Catheter dysfunction (need for thrombolytic infusion or catheter change) led to 0.88 admissions per 1000 catheter days.

CONCLUSION

Translumbar inferior vena caval CVCs can offer relatively safe and effective long-term haemodialysis access in patients with no other options.

Experience of 70-cm-long femoral tunnelled twin Tesio catheters for chronic haemodialysis

BACKGROUND

Tunnelled femoral catheters with their tip in the lower inferior vena cava (IVC) are proposed only in few cases, but they often provide less than optimal blood flows and frequently have complications. The aim of this prospective observational study is to evaluate the use of 70-cm-long tunnelled cuffed femoral twin Tesio catheters with their tip in the upper IVC for haemodialysis.

METHODS

Between May 2007 and May 2009, 25 tunnelled femoral catheters (fCVC) have been placed in 25 patients (77.7 +/- 10.8 years) with exhausted thoracic venous accesses or old patients with several comorbidities. Two 10 Fr carbothane 70-cm-long Tesio catheters with a Dacron cuff at 45 cm from the tip were placed in the femoral vein of each patient and then tunnelled; tips were in the upper third of the IVC. fCVCs were removed for either malfunction (Qb < 200 ml/min) or infection that did not resolve with antibiotics.

RESULTS

Technical success of placement was 100%. The 6- and 12-month assisted primary patency rate were respectively 67 +/- 13% and 54 +/- 17%. The mean session Kt/V was 1.45 +/- 0.19, and the blood flow was 270 +/- 17 ml/min. Six fCVCs have been removed: three for infection, one for accidental damaging and two for the making of a different vascular access. The main complications were 2 catheter tip thrombi, 3 tunnel infections and 11 fCVC-related bacteraemia (1.77 episodes per 1000 CVC-days).

CONCLUSION

The placement of twin fCVCs with their tip in the high IVC can provide an adequate dialysis and can be considered for patients with no remaining thoracic accesses.

Does heparin coating improve patency or reduce infection of tunneled dialysis catheters?

BACKGROUND AND OBJECTIVES

Tunneled dialysis catheters are prone to frequent malfunction and infection. Catheter thrombosis occurs despite prophylactic anticoagulant locks. Catheter thrombi may also serve as a nidus for catheter infection, thereby increasing the risk of bacteremia. Thus, heparin coating of catheters may reduce thrombosis and infection. This study evaluated whether heparin-coated hemodialysis catheters have fewer infections or greater cumulative survival than noncoated catheters.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We retrospectively queried a prospective access database to analyze the outcomes of 175 tunneled dialysis catheters placed in the internal jugular vein, including 89 heparin-coated catheters and 86 noncoated catheters. The primary outcome was cumulative catheter survival, and the secondary outcome was infection-free catheter survival.

RESULTS

The two patient groups were similar in demographics and clinical and catheter features. Catheter-related bacteremia occurred less frequently with heparin-coated catheters than with noncoated catheters (34 versus 60%, P < 0.001). Cumulative catheter survival was similar in heparin-coated and noncoated catheters (hazard ratio, 0.87; 95% confidence interval, 0.55 to 1.36; P = 0.53). On multiple variable survival analysis including catheter type, age, sex, diabetes, coronary artery disease, peripheral vascular disease, cerebrovascular disease, catheter location, and previous catheter, only catheter location predicted cumulative catheter survival (hazard ratio, 2.03; 95% CI, 1.27 to 3.25, with the right internal jugular location being the reference group, P = 0.003). The frequency of thrombolytic instillation was 1.8 per 1000 catheter-days in both groups.

CONCLUSIONS

Heparin coating decreases the frequency of catheter-related bacteremia but does not reduce the frequency of catheter malfunction.

Thigh grafts: a preferable alternative to catheters when upper extremity access sites are exhausted

Hemodialysis patients with failed upper extremity (arm) access sites comprise 5-10% of the dialysis population. In these patients, arm vessels are either unsuitable for access placement due to trauma or peripheral vascular disease, or have been exhausted following dialysis usage. Synthetic grafts in the lower extremity (thigh) would benefit these patients, but surgeons are often reluctant to place them, due to concerns of infection and vascular complications. As a result, these patients receive tunneled central venous catheters as their permanent dialysis access. Recent studies have shown, however, that survival and complication rates of thigh grafts are similar to arm grafts and fistulas. Moreover, thigh grafts have lower infection and mortality rates than catheters and provide higher blood flows and dialysis adequacy. In this editorial we argue that thigh grafts are the better option in patients who have lost all arm access sites; they should be placed in preference to tunneled central venous catheters.

Vascular access-related infections: definitions, incidence rates, and risk factors

Hemodialysis is associated with a high risk of morbidity and mortality, often caused by infections. Infections account for approximately 15% of all deaths in this patient population (the second leading cause after cardiovascular events) and for about one-fifth of admissions. Approximately one-fourth of infection-related admissions are caused by dialysis-associated peritonitis or vascular access infection that may lead to such significant complications as endocarditis or death. Published studies that assessed the determinants of hemodialysis-related vascular infections reported inconsistent findings. Variations in the definitions of infection among these studies despite the existence of standard guidelines proposed by at least 3 major work groups may explain, at least in part, these inconsistencies. A comprehensive in-depth review of those studies is needed to examine the inconsistencies in the published results. We first revised the existing vascular access-related infection definitions, then conducted a narrative review of the published literature that examined predictors of vascular access-related infections, highlighting the heterogeneity in methods and findings. Better understanding of the risk factors for vascular access-related infections may inform efficacious prevention strategies and lead to early detection of infections and improved patient care.

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.

Factors affecting long-term survival of tunnelled haemodialysis catheters--a prospective audit of 812 tunnelled catheters

BACKGROUND

In 2001, in the US, 23% of haemodialysis patients were dialysing through tunnelled venous catheters (TVCs), and in the UK (2006) there were 28% of prevalent patients using catheters. It is unlikely that numbers will significantly decrease. We present the results of a prospective audit of the survival of 812 TVCs placed in 492 patients at our institution over a 6-year period (comprising 212 048 patient catheter days or 7068 patient catheter months of follow-up). Four different designs of catheter were studied: Split-Cath III (Medcomp), HemoSplit (Bard), Tesio twin catheter (Medcomp) and Permcath (Quinton).

METHODS

We used Kaplan-Meier survival analysis with log-rank test, to compare the effect of different parameters on catheter survival. The relative importance of significant parameters was determined by Cox regression analysis.

RESULTS

We have shown a significant catheter survival advantage of first catheters over second and subsequent insertions, of right internal jugular site over left internal jugular and thereafter over femoral site, and of non-diabetic over diabetic patients. Patient age, sex and operator (physician in ward-based procedure room under ultrasound control or surgeon in operating theatre under fluoroscopic assistance) did not significantly affect survival. The Permcath design demonstrated inferior survival in all but first catheter insertions in catheter-naïve patients. The HemoSplit and Tesio twin catheter designs demonstrated best survival overall. By Cox proportional hazard modelling the design and the position of the TVC seemed to be the most significant independent survival factors.

CONCLUSIONS

Clinicians need accurate data regarding catheter survival, mode of insertion and design, to inform practice.

Current management of vascular access

Optimizing vascular access outcomes remains an ongoing challenge for clinical nephrologists. All other things being equal, fistulas are preferred over grafts, and grafts are preferred over catheters. Mature fistulas have better longevity and require fewer interventions, as compared with mature grafts. The major hurdle to increasing fistula use is the high rate of failure to mature of newly created fistulas. There is a desperate need for enhanced understanding of the mechanisms of failure to mature and the optimal type and timing of interventions to promote maturity. Grafts are prone to frequent stenosis and thrombosis. Surveillance for graft stenosis with preemptive angioplasty may reduce graft thrombosis, but recent randomized clinical trials have questioned the efficacy of this approach. Graft stenosis results from aggressive neointimal hyperplasia, and pharmacologic approaches to slowing this process are being investigated in clinical trials. Catheters are prone to frequent thrombosis and infection. The optimal management of catheter-related bacteremia is a subject of ongoing debate. Prophylaxis of catheter-related bacteremia continues to generate important clinical research. Close collaboration among nephrologists, surgeons, radiologists, and the dialysis staff is required to optimize vascular access outcomes and can be expedited by having a dedicated access coordinator to streamline the process. The goal of this review is to provide an update on the current status of vascular access management.

Use of the femoral vein as insertion site for tunneled hemodialysis catheters

PURPOSE

To determine the outcome of tunneled hemodialysis catheters inserted through the common femoral vein.

MATERIALS AND METHODS

From April 2000 to June 2003, 33 consecutive patients had 86 tunneled hemodialysis catheters inserted through the femoral vein. There were 14 male and 19 female patients with a mean age of 56 years. Seventeen patients had bilateral central venous and/or superior vena cava (SVC) occlusions, 12 patients had unilateral central venous occlusions and were to receive contralateral arteriovenous fistulas or arteriovenous polytetrafluoroethylene grafts, and 4 patients received femoral catheters for other reasons. The technical success, complications, and clinical outcomes of these procedures were retrospectively evaluated.

RESULTS

All procedures were technically successful. Fifty-seven catheters were inserted into the right femoral vein and 29 into the left femoral vein. This included 25 catheter exchanges in 13 patients. Two patients developed thigh hematomas. Follow-up data were available for 68 catheters; mean follow-up period was 51 days with a total of 3,484 catheter days. The catheter-related infection rate was 6.3 per 1,000 catheter days; 22 catheters were removed for infection. Eighteen catheters were removed because of poor blood flows (<200 mL/min). Thirteen catheters were removed because they had become retracted. Primary catheter patency was 44% at 1 month.

CONCLUSIONS

The femoral vein provides an alternative access site for insertion of tunneled hemodialysis catheters when conventional sites are not available. However, tunneled femoral hemodialysis catheters have low primary patency rates and significant complications. Catheter retraction is a unique and common problem.

Central venous catheter-related bacteremia in chronic hemodialysis patients: epidemiology and evidence-based management

Central venous catheter-related blood stream infection (CRBSI) is a major cause of morbidity and mortality in patients with end-stage renal disease treated with chronic hemodialysis. Risk factors include Staphylococcus aureus nasal colonization, longer duration of catheter use, previous bacteremia, older age, higher total intravenous iron dose, lower hemoglobin and serum albumin levels, diabetes mellitus and recent hospitalization. Symptoms that raise clinical suspicion of bacteremia in chronic hemodialysis patients are fevers and chills. When CRBSI is suspected, blood cultures should be obtained and empirical therapy with broad spectrum intravenous antibiotics initiated. The diagnosis of CRBSI is confirmed by isolation of the same microorganism from quantitative cultures of both the catheter and the peripheral blood of a patient that has clinical features of infection without any other apparent source. Gram-positive cocci, predominantly S. epidermidis and S. aureus, cause bacteremia in two-thirds of cases. Among the various approaches to management of CRBSI, removal and delayed replacement of the catheter, catheter exchange over a guidewire in selected patients, and the use of antimicrobial/citrate lock solutions have all been found to be promising for treatment and/or prevention; however, resolution of issues regarding selection, dose, duration and emergence of antibiotic-resistant organisms with chronic use of antibiotic lock solutions, as well as the safety of long-term use of trisodium citrate lock solutions, await further randomized, multicenter trials involving larger samples of hemodialysis patients.

Displacement of the inferior vena cava as a factor limiting catheter performance in long-term hemodialysis patients

We report a case of a lady affected by autosomal dominant polycystic kidney disease who had been on hemodialyis for 24 years. She has exhausted all options for arterious-venous fistula. The presence of an acquired anatomical abnormality was an obstacle in order to get appropriate blood flow from standard tunnelled femoral catheters. The enlarged right kidney was pushing the inferior vena cava to the left side of the abdomen, and the abnormality was demonstrated by phlebography. Only after placing a cuffed catheter 53 cm long in her left femoral vein we could dialyze efficiently. Venography is mandatory before placing a cuffed catheter especially in uremic patients with long history of access failure, because it saves costs.

Complications, Effects on Dialysis Dose, and Survival of Tunneled Femoral Dialysis Catheters in Acute Renal Failure

BACKGROUND

Availability of a functional vascular access is a mandatory prerequisite for extracorporeal renal replacement therapy in patients with acute renal failure. The femoral site of insertion commonly is chosen because it is an easy and convenient access. However, an array of complications may substantially alter the quality of treatment, and it appears that catheter-related morbidity and dysfunction are more frequent with the femoral than internal jugular site. This study is designed to evaluate the potential benefits of using soft silicone tunneled catheters ((ST)Caths) at the femoral site.

METHODS

Thirty patients with acute renal failure treated by intermittent hemodialysis (IHD) and/or continuous venovenous hemodiafiltration (CVVHDF) were assigned to either twin (ST)Caths or twin polyurethane nontunneled femoral catheters. Time necessary for catheter insertion, catheter-related complications, and catheter lifespan were monitored. Catheter performance during IHD and the effect of catheter type on dialysis dose were evaluated.

RESULTS

The time necessary for (ST)Cath insertion was significantly longer. The incidence of vein thrombosis and catheter-related infection was lower, and the ratio of venous return pressure to catheter blood flow was better with an (ST)Cath. Recirculation rates were similar for both types of catheters. Whether treated by using IHD or CVVHDF, patients with an (ST)Cath benefited from a greater delivered dialysis dose. Multivariate analysis confirmed that (ST)Cath use was a determinant factor to optimize dialysis dose delivery. (ST)Cath patency was significantly longer.

CONCLUSION

In patients with acute renal failure, use of an (ST)Cath minimizes catheter-related morbidity and improves dialysis efficiency compared with conventional femoral catheters.

Care of the end-stage renal disease patient on dialysis in the ED

End-stage renal disease is a major public health problem. In the United States, more than 350,000 patients are being treated with either hemodialysis or continuous ambulatory peritoneal dialysis. Given the high burden of comorbidities in these patients, it is imperative that emergency physicians be aware of the complexities of caring for acute illnesses in this population. This article reviews the common medical problems that bring patients with end-stage renal disease to the emergency department, and their evaluation and management.

Central venous catheter-associated bloodstream infections in hemodialysis patients: Another patient safety bundle?

In a previous issue ofThe Canadian Journal of Infectious Diseases & Medical Microbiology, we reviewed the 'Safer Healthcare Now!' campaign's focus on reducing central venous catheter (CVC)-associated bloodstream infections (BSIs) as a way of improving patient safety (1). This initiative is focused on preventing CVC-associated BSIs in intensive care units. However, other patient groups are also at risk for CVC-related BSIs, suggesting that there are other individuals who would benefit from preventive efforts. A 1996 hospital-wide survey of nosocomial bacteremia in an Israeli university hospital (2) found that 9% of infected patients were on chronic hemodialysis. Surveillance in 73 hospitals in England between 1997 and 2001 found a CVC BSI rate of 21/1000 nephrology patients at risk who were hospitalized in teaching hospitals (3). This rate was similar to that found in special care neonatal units, although not quite one-half that of patients in a general intensive care unit. In a population-based survey performed in the Calgary Health Region from 2000 to 2002 (4), hemodialysis (HD) posed the greatest risk (RR 208.7; 95% CI 142.9 to 296.3) for acquiring severe BSI.