Fistula First Initiative: Historical Impact on Vascular Access Practice Patterns and Influence on Future Vascular Access Care

Maturation Rates of Arteriovenous Fistulas Using Small Veins in the Era of Endovascular Interventions

BACKGROUND

Traditional practice suggests the abandonment of veins smaller than 3 mm in diameter for arteriovenous fistula (AVF) creation because of a low rate of maturation. This study aims to show that with balloon-assisted maturation (BAM), undersized veins can be used to create functional AVFs with a high rate of success.

METHODS

All patients who underwent AVF creation between 2014 and 2018 at a tertiary academic medical center were retrospectively reviewed. The patients without preoperative vein mapping, those who failed to follow-up, and the patients who were not on dialysis were excluded. A fistula was considered to be mature if it was successfully cannulated for dialysis. A total of 596 patients were identified for analysis. The cohort was divided into the small-vein group (SVG, <2.5 mm) and large-vein group (LVG, ≥2.5 mm) based on preoperative vein size. Categorical variables were analyzed with the chi-squared test for their association with maturation status. Continuous variables were analyzed with the Wilcoxon rank sum test. A P-value less than 0.05 was considered significant.

RESULTS

In the study cohort, 61.9% of the patients were male, with an average age of 62.8 ± 13.7 years, and an average preoperative vein size of 2.9 ± 1.1 mm. With similar demographic distribution, the participants in the SVG (n = 216) had significantly smaller preoperative vein size of 1.9 ± 0.4 mm than the patients in the LVG (n = 380), 3.5 ± 0.8 mm (P = 0.001). There were significantly more radio-cephalic AVFs created in the SVG (77.8% versus 48.7%, P < 0.0001). The overall maturation rate was 83.1% (n = 495), 219 fistulas (36.7%) matured primarily and 276 (46.3%) required interventions. Ninety-one percent of the patients required only 1 or 2 BAMs to achieve maturation. The SVG achieved a maturation rate of 75.9% as compared with 87.1% in the LVG (P = 0.002). A significantly higher number of patients in the SVG required BAM for maturation as compared with the LVG (67.7% versus 49.9%, P = 0.0002); however, there was no difference in the average number of BAMs required for fistula maturation between the groups (1.5 ± 0.8 for the SVG vs. 1.4 ± 0.7 for the LVG). In multivariable logistic regression analysis, vein size ≥2.5 mm (odds ratio (OR) = 2.11, confidence interval (CI): 1.36-3.27, P = 0.0009) and male sex (OR = 2.30, CI: 1.49-3.57, P = 0.0002) were independent predictors of maturation.

CONCLUSIONS

Small veins can be used for AVF creation with lower but still favorable maturation rates using BAM interventions, especially in male patients. This practice can increase the creation of autogenous dialysis access and potentially reduce complications related to prosthetic dialysis access.

Supply and Distribution of Vascular Access Physicians in the United States: A Cross-Sectional Study

Background

Because functioning permanent vascular access (arteriovenous fistula [AVF] or arteriovenous graft [AVG]) is crucial for optimizing patient outcomes for those on hemodialysis, the supply of physicians placing vascular access is key. We investigated whether area-level demographic and healthcare market attributes were associated with the distribution and supply of AVF/AVG access physicians in the United States.

Methods

A nationwide registry of physicians placing AVFs/AVGs in 2015 was created using data from the United States Renal Data System and the American Physician Association's Physician Masterfile. We linked the registry information to the Area Health Resource File to assess the supply of AVF/AVG access physicians and their professional attributes by hospital referral region (HRR). Bivariate analysis and Poisson regression were performed to examine the relationship between AVF/AVG access physician supply and demographic, socioeconomic, and health resource conditions of HRRs. The setting included all 50 states. The main outcome was supply of AVF/AVG access physicians, defined as the number of physicians performing AVF and/or AVG placement per 1000 prevalent patients with ESKD.

Results

The majority of vascular access physicians were aged 45-64 (average age, 51.6), male (91%), trained in the United States (76%), and registered in a surgical specialty (74%). The supply of physicians varied substantially across HRRs. The supply was higher in HRRs with a higher percentage white population (β=0.44; SEM=0.14; P=0.002), lower unemployment rates (β=-10.74; SEM=3.41; P=0.002), and greater supply of primary care physicians (β=0.18; SEM=0.05; P=0.001) and nephrologists (β=15.89; SEM=1.22; P<0.001).

Conclusions

Geographic variation was observed in the supply of vascular access physicians. Higher supply of such specialist physicians in socially and economically advantaged areas may explain disparities in vascular access and outcomes in the United States and should be the subject of further study and improvement.

The safety of bovine tissue arterial repair in removal of infected prosthetic hemodialysis grafts

BACKGROUND

More than 400,000 Americans require dialysis, and many receive it via a prosthetic arteriovenous graft. Infection of these grafts is rare, but associated with significant morbidity and mortality. The gold standard is total graft excision with arteriotomy closure. This was previously done with autologous vein, but bovine tissue offers a reasonable alternative. The objective of this article is to evaluate a community hospital experience with bovine tissue arterial repair after total graft excision of infected prosthetic arteriovenous graft.

METHODS

A retrospective review was performed of all cases of infected prosthetic arteriovenous graft removal with bovine tissue arterial repair was performed. Thirteen cases were identified. Presentation, location of graft, and causative organism were reviewed; outcomes including reoperation and mortality were recorded.

RESULTS

Of the 13 patients, 12 (92%) had positive cultures of the graft, bloodstream, or wound. Methicillin-resistant Staphylococcus aureus was the most commonly isolated organism (54%). There were two unplanned reoperations including hematoma drainage and wound debridement within the first year. Over the 1-year follow-up period, 1 patient died for a mortality of 8%. There were no re-infections during follow-up.

DISCUSSION

Prosthetic arteriovenous graft infection remains a difficult challenge and is associated with significant morbidity and mortality. It presents in a variety of ways, including within an old thrombosed graft. Over the last several years, the causative organism has increasingly become drug resistant. Treatment with total graft excision requires arteriotomy closure, and for this bovine tissue has been demonstrated to be a viable option.

Total Resection of Infected Peripheral Hemodialysis Grafts Has a Favorable Impact on Outcomes

BACKGROUND

Surgical resection could be an eradication treatment for patients with infected hemodialysis arteriovenous grafts (AVGs). This study aimed to investigate the outcomes of 3 surgical methods, including total resection, subtotal resection, and revision.

METHODS

The patients who underwent surgical excision of infected AVGs performed at a single center from August 2012 to March 2019 were retrospectively analyzed. The following 3 surgical methods were used in our study: revision, subtotal resection, and total resection. Patients' demographics, medical history, perioperative details, reconstruction time, and follow-up data were collected. The outcomes including perioperative complications (within 30 days), mortality, reinfection rate of AVGs, with new access reconstruction or not, and the outcomes between reconstruction and nonreconstruction in the follow-up period were evaluated.

RESULTS

Forty-one patients had infected AVGs in our study. Patients' mean age was 62 years, and 65.9% of the patients were female. The mean duration from the time of diagnosis to the operation was 14.4 days. Signs and symptoms at presentation included fever (51.2 %), swelling (43.9%), pain (58.5%), erythematous change (92.7%), and more severe features, such as altered consciousness (14.6%) and hypotension (12.2%). The pathological changes in the infected grafts included bleeding (29.3%), pus formation (73.2%), pseudoaneurysm (26.8%), and graft exposure (17.1%). Wound and graft cultures revealed an infectious etiology with fungi (7.3%), Pseudomonas aeruginosa (12.2%), Enterococcus spp. (2.4%), and Staphylococcus spp. (58.5%), with methicillin-resistant Staphylococcus aureus accounting for only 7.3%. Total resection, subtotal resection, and revision surgery were performed in 17.1%, 63.4%, and 19.5% of patients, respectively. Seven patients with complications required reoperation (17.1%), and adhesion ileus and hospital-acquired pneumonia occurred in only 2.4% and 7.3% of patients, respectively. During follow-up, most patients (82.9%) had reconstruction of the peripheral hemodialysis access with mean time of 64.3 (range: 21-92) days; mean time of use of new access was 90.5 days; and mean time of removal of catheter was about 106.3 days. Mortality rates in patients without and with reconstructed AV access during follow-up were 50% and 18%, respectively (P < 0.004). Eight cases (19.5%) had recurrence of AV access infections during follow-up; of these, 2 had revision surgery and 6 had subtotal resection. However, no patient with total resection had recurrent infections.

CONCLUSIONS

The total resection group had no recurrent infection compared to the subtotal and revision groups. In addition, patients with reconstruction of peripheral hemodialysis access had a low mortality rate during the follow-up period.

Reasons for long-term tunneled dialysis catheter use and associated morbidity

OBJECTIVE

Tunneled dialysis catheters (TDCs) are generally used as a temporary means to provide hemodialysis until permanent arteriovenous (AV) access is established. However, some patients may have long-term catheter-based hemodialysis because of the lack of alternatives for other dialysis access. Our objective was to evaluate characteristics of patients with, reasons for, and mortality associated with long-term TDC use.

METHODS

A retrospective single-institution analysis was performed. Long-term TDC use was defined as >180 days without more than a 7-day temporary removal time. Reasons for long-term TDC use and complications were recorded. Summary statistics were performed. Kaplan-Meier analysis compared mortality between patients with long-term TDC use and a comparison cohort who underwent AV access creation with subsequent TDC removal.

RESULTS

We identified 50 patients with long-term TDC use from 2013 to 2018. The average age was 63 years, 44% were male, and 76% were African American. Previous TDC use was found in 42% of patients with subsequent removal after alternative access was established. Median TDC duration was 333 days (range, 185-2029 days). The primary reasons for long-term TDC use were failed (occluded) AV access (34%), nonmaturing AV (nonoccluded) access (32%), delayed AV access placement (14%), no AV access options (10%), patient refusal for AV access placement (6%), and medically high risk for AV access placement (4%). In 46% of patients, TDC complications including central venous stenosis (33.4%), TDC-related infections (29.6%), TDC displacement (27.8%), and thrombosis (7.9%) occurred. Overall, 47.6% required a catheter exchange during the prolonged TDC period. The majority (76.4%) had the catheter removed because of established alternative access during follow-up. The long-term TDC group, in relation to the comparator group (n = 201), had fewer male patients (44% vs 61.2%; P = .028) and higher proportion of congestive heart failure (66% vs 40.3%; P = .001). Kaplan-Meier analysis showed no significant difference in survival at 24 months for the long-term TDC group compared with the comparator group (93.6% vs 92.7%; P = .28).

CONCLUSIONS

Patients with long-term TDCs experienced significant TDC-related morbidity. Whereas permanent access is preferable, some patients may require long-term TDC use because of difficulty in establishing a permanent access, limited access options, and patient preference. There was no difference in survival between the groups.

Meeting Treatment Goals in Patients on Extramural Dialysis in Health Social Security in Mexico

INTRODUCTION

For the majority of renal replacement therapy history, the main treatment option for patients with end-stage renal disease (ESRD) in Mexico has been peritoneal dialysis. However, the use of hemodialysis is overwhelmingly increasing, driving public health care institutions to subrogate this service. Even when the actual hiring model for subrogation is accurate, there is a lack of quality control points in the hemodialysis prescription, poor adherence to clinical practice guidelines, and a few or no record of outcomes in hemodialysis patients of these subrogated services. The objective of this work is to fill this information gap to allow for uniform and safe hemodialysis for patients of Mexico.

MATERIAL AND METHODS

An observational and cross-sectional study was performed, including all patients receiving chronic hemodialysis treatment in subrogated units of Mexican Social Security Institute (IMSS) in the northern region of Mexico City. Clinical and biochemical data as well as hemodialysis dose by Kt/V and urea reduction rate were collected and evaluated. To determine distribution, mean or median and SD or interquartile range were used; for nominal variables, the difference in proportions was estimated using the χ2 test; proportions were analyzed for biochemical values using the statistical package SPSS version 25.

RESULTS

In our study, >60% (485) of the patients were anemic with an average hemoglobin of 9.39 mg/dL (SD ± 1.83); serum calcium was found below 8.4 mg/dL in 51.3% (383) of patients, and only in 45.8% (342) was at an optimal level of this parameter. Only 33.5% of patients have arteriovenous fistula for dialysis access. The hemodialysis dose was optimal in >75% of patients.

CONCLUSIONS

It is necessary to enhance and monitor treatment of comorbidities in patients with ESRD in subrogated hemodialysis units in México. We observed adequate prescription of hemodialysis in a majority of patients, achieving quality control points for removal of nitrogen products. Yet, there is a lack of quality control of comorbidities; therefore, we should aim to optimize treatment for mineral-bone disorder, anemia, and nutritional status.

A randomized pilot study to evaluate graft versus fistula vascular access strategy in older patients with advanced kidney disease: results of a feasibility study

BACKGROUND

Although older adults encompass almost half of patients with advanced chronic kidney disease, it remains unclear which long-term hemodialysis vascular access type, arteriovenous fistula or arteriovenous graft, is optimal with respect to effectiveness and patient satisfaction. Clinical outcomes based on the initial AV access type have not been evaluated in randomized controlled trials. This pilot study tested the feasibility of randomizing older adults with advanced kidney disease to initial arteriovenous fistula versus graft vascular access surgery.

METHODS

Patients 65 years or older with pre-dialysis chronic kidney disease or incident end-stage kidney disease and no prior arteriovenous vascular access intervention were randomized in a 1:1 ratio to undergo surgical placement of a fistula or a graft after providing informed consent. Trial feasibility was evaluated as (i) recruitment of ≥ 70% of eligible participants, (ii) ≥ 50 to 70% of participants undergo placement of index arteriovenous access within 90 to 180 days of enrollment, respectively, (iii) ≥ 80% adherence to study-related assessments, and (iv) ≥ 70% of participants who underwent index arteriovenous access placement will have a follow-up duration of ≥ 12 months after index surgery date.

RESULTS

Between September 2018 and October 2019, 81% (44/54) of eligible participants consented and were enrolled in the study; 11 had pre-dialysis chronic kidney disease, and 33 had incident or prevalent end-stage kidney disease. After randomization, 100% (21/21) assigned to arteriovenous fistula surgery and 78% (18/23) assigned to arteriovenous graft surgery underwent index arteriovenous access placement within a median (1st, 3rd quartile) of 5.0 (1.0, 14.0) days and 13.0 (5.0, 44.3) days, respectively, after referral to vascular surgery. The completion rates for study-specific assessments ranged between 40.0 and 88.6%. At median follow-up of 215.0 days, 5 participants expired, 7 completed 12 months of follow-up, and 29 are actively being followed. Assessments of grip strength, functional independence, and vascular access satisfaction were completed by > 85% of patients who reached pre-specified post-operative assessment time point.

CONCLUSIONS

Results from this study reveal it is feasible to enroll and randomize older adults with advanced kidney disease to one of two different arteriovenous vascular access placement surgeries. The study can progress with minor protocol adjustments to a multisite clinical trial.

TRIAL REGISTRATION

Clinical Trials ID, NCT03545113.

Vascular Access and Risk of Bloodstream Infection Among Older Incident Hemodialysis Patients

Rationale & Objective

Most new patients with end-stage renal disease (ESRD) initiate hemodialysis (HD) with a central venous catheter (CVC) and later transition to a permanent vascular access with lower infection risk. The benefit of early fistula use in preventing severe infections is incompletely understood. We examined patients' first access and subsequent transitions between accesses during the first year of HD to estimate the risk for bloodstream infection (BSI) associated with incident and time-dependent use of HD access.

Study Design

A retrospective cohort study using enhanced 5% Medicare claims data.

Setting & Participants

New patients with ESRD initiating HD between January 1, 2011, and December 31, 2012, and having complete pre-ESRD Medicare fee-for-service coverage for 2 years.

Exposure

The incident and prevalent use of CVC, graft, or fistula as determined from monthly reports to the Centers for Medicare & Medicaid Services by HD providers.

Outcome

Incident hospitalization with a primary/secondary diagnosis of BSI (International Classification of Diseases, Ninth Revision, Clinical Modification code 038.xx or 790.7).

Analytical Approach

Extended survival analysis accounting for patient confounders.

Results

Of 2,352 study participants, 1,870 (79.5%), 77 (3.3%), and 405 (17.2%) initiated HD with a CVC, graft, and fistula, respectively. During the first year, the incident BSI hospitalization rates per 1,000 person-days were 1.3, 0.8, and 0.3 (P<0.001) in patients initiating with a CVC, graft, and fistula, respectively. After adjusting for confounders, incident fistula use was associated with 61% lower risk for BSI (HR, 0.39; 95% CI, 0.28-0.54; P<0.001) compared with incident CVC or graft use. The prevalent fistula or graft use was associated with lower risk for BSI compared with prevalent CVC use (HRs of 0.30 [95% CI, 0.22-0.42] and 0.47 [95% CI, 0.31-0.73], respectively).

Limitations

Restricted to an elderly population; potential residual confounding.

Conclusions

Incident fistula use was associated with lowest rates of BSI, but the majority of beneficiaries with pre-ESRD insurance initiated HD with a CVC. Strategies are needed to improve pre-ESRD fistula placement.

Smart Flow for the evaluation of the hemodialysis arteriovenous fistula

BACKGROUND

Smart Flow is an innovative tool available on the Carestream Touch Prime Ultrasound machines, which provides automated blood flow measurement and shows the vectors that form the blood flow in the vessel. We compared the use of Smart Flow with traditional Duplex Doppler Ultrasound to evaluate blood flow of arteriovenous fistulas in prevalent hemodialysis patients.

METHODS

A total of 31 chronic patients on hemodialysis were enrolled. Blood flow was measured on the brachial artery with Smart Flow and duplex Doppler ultrasound. In a subset of 26 patients, a video of the juxta-anastomotic efferent vein was recorded and analyzed to calculate an index of flow turbulence.

RESULTS

We enrolled 21 males and 10 females aged 68.52 ± 11.64 years at the time of evaluation with an average arteriovenous fistulas vintage of 50.23 ± 47.42 months and followed them up for 18.03 ± 5.18 months. Smart Flow and Duplex Doppler Ultrasound blood flow measurements positively correlated (p < 0.0001) in the same patient but Smart Flow gave higher blood flow values (995.0 vs 730.3 mL/min, p < 0.0001), and the Duplex Doppler Ultrasound blood flow standard deviation was similar to Smart Flow (125.4 vs 114.4 mL/min, p < 0.0001). The time needed to evaluate arteriovenous fistulas with Smart Flow was significantly shorter than Duplex Doppler Ultrasound (67.58 ± 19.89 vs 146.3 ± 26.35 s, p < 0.0001). No correlation was found between blood flow turbulence and the subsequent access failure.

CONCLUSION

Smart Flow is reliable, reproducible, and faster than traditional duplex ultrasound. However, the additional information given by the Smart Flow technique does not seem to add any further benefits in terms of prediction of the access failure.

A Primer on Quality Assurance and Performance Improvement for Interprofessional Chronic Kidney Disease Care: A Path to Joint Commission Certification

Interprofessional care for chronic kidney disease facilitates the delivery of high quality, comprehensive care to a complex, at-risk population. Interprofessional care is resource intensive and requires a value proposition. Joint Commission certification is a voluntary process that improves patient outcomes, provides external validity to hospital administration and enhances visibility to patients and referring providers. This is a single-center, retrospective study describing quality assurance and performance improvement in chronic kidney disease, Joint Commission certification and quality outcomes. A total of 440 patients were included in the analysis. Thirteen quality indicators consisting of clinical and process of care indicators were developed and measured for a period of two years from 2009–2017. Significant improvements or at least persistently high performance were noted for key quality indicators such as blood pressure control (85%), estimation of cardiovascular risk (100%), measurement of hemoglobin A1c (98%), vaccination (93%), referrals for vascular access and transplantation (100%), placement of permanent dialysis access (61%), discussion of advanced directives (94%), online patient education (71%) and completion of office visit documentation (100%). High patient satisfaction scores (94–96%) are consistent with excellent quality of care provided.

Cefazolin-gentamicin versus taurolidine-citrate for the prevention of infection in tunneled central catheters in hemodialysis patients: A quasi-experimental trial

BACKGROUND

Catheter-related bloodstream infection (CR-BSI) is one of various complications related to hemodialysis (HD). As a result of the high rate of infection, the use of lock solutions for the prevention of CR-BSI has been studied. However, adverse effects of lock solution, such as increased emergence of strains resistant to antibiotics, which is an important concern, need to be investigated further. The aim of this study was to compare the efficacy of lock solution using a combination of cefazolin and gentamicin versus taurolidine and citrate in reducing CR-BSI in patients undergoing HD and to identify any adverse effects.

METHODS

A prospective observational study was performed at two dialysis centers. Patients using new tunneled central venous catheters (CVC) for HD were included. Patients with a tunneled CVC were assigned to receive either antibiotic lock solution (group 1: gentamicin 7mg/ml+cefazolin 12mg/ml+heparin 3500IU/ml) or lock solution with TauroLock-Hep500 (group 2: taurolidine citrate 4%+heparin 500 IU/ml) during the inter-dialysis period. The patients were allocated to these groups according to the hemodialysis center they were attending.

RESULTS

A total of 145 CVCs were implanted in 127 patients and were followed for 15 months: 77 CVCs (65 patients) were placed in group 1 and 68 CVCs (62 patients) in group 2. There was no difference between the two groups with regard to CR-BSI (events per 1000 catheter-days: group 1=0.79, group 2=1.10; p=0.18) or exit site infection rates (events per 1000 catheter-days: group 1=2.45, group 2=1.83; p=0.37). The groups differed in ESI pathogens, with gram-positive oxacillin-resistant pathogens more frequent in group 1 (31.8% vs. 5.0%; p=0.003). The two groups were similar in mechanical complications. In the Cox regression analysis, the internal jugular vein site was a protective factor for all catheter removal complications (hazard ratio (HR) 0.41, 95% confidence interval (CI) 0.19-0.91) and mechanical complications (HR 0.16, 95% CI 0.065-0.41); only ESI was a risk factor for all catheter removal complications (HR 1.79, 95% CI 1.04-3.07) and mechanical complications (HR 5.64, 95% CI 1.65-19.3).

CONCLUSIONS

The efficacy of both lock solutions was similar in preventing infections related to tunneled CVCs for HD. However, there were more oxacillin-resistant strains in patients who received antibiotic lock solution. Further studies are required to determine the optimal drug regimen and concentrations for lock solution and the associated adverse effects.

Determinants and outcomes of access-related blood-stream infections among Irish haemodialysis patients; a cohort study

Background

Infections are the second leading cause of death and hospitalisation among haemodialysis (HD) patients. Rates of access-related bloodstream infections (AR-BSI) are influenced by patient characteristics and local protocols. We explored factors associated with AR-BSI in a contemporary cohort of HD patients at a tertiary nephrology centre.

Methods

A retrospective cohort of 235 chronic HD patients was identified from a regional dialysis programme between Jan 2015 and Dec 2016. Data on demographics, primary renal disease, comorbid conditions and dialysis access type were obtained from the Kidney Disease Clinical Patient Management System (KDCPMS). Data on blood cultures were captured from the microbiology laboratory. Poisson regression with robust variance estimates was used to compare infection rates and relative risk of AR-BSI according to the site and type of vascular access.

Results

The mean age was 65 (± 15) years, 77% were men, and the median follow up was 19 months (IQR: 10–24 months), accumulating 2030 catheter-months and 1831 fistula-months. Overall rates of AR-BSI were significantly higher for central venous catheter (CVC) compared to arteriovenous fistula (AVF), (2.22, 95% (CI): 1.62–2.97) versus 0.11 (0.01–0.39) per 100 patient-months respectively), with a rate ratio of 20.29 (4.92–83.66), p < 0.0001. This pattern persisted across age, gender and diabetes subgroups. Within the CVC subgroup, presence of a femoral CVC access was associated with significantly higher rates of AR-BSI (adjusted RR 4.93, 95% CI: 2.69–9.01). Older age (75+ versus < 75 years) was not associated with significant differences in rates of AR-BSI in the unadjusted or the adjusted analysis. Coagulase negative Staphylococcus (61%) and Staphylococcus aureus (23%) were the predominant culprits. AR-BSIs resulted in access loss and hospitalisation in 57 and 72% of events respectively, and two patients died with concurrent AR-BSI.

Conclusions

Rates of AR-BSI are substantially higher in CVC than AVF in contemporary HD despite advances in catheter design and anti-infective protocols. This pattern was consistent in all subgroups. The policy of AVF preference over CVC should continue to minimise patient morbidity while at the same time improving anti-infective strategies through better care protocols and infection surveillance.

Electronic supplementary material

The online version of this article (10.1186/s12882-019-1253-x) contains supplementary material, which is available to authorized users.

Early cannulation grafts for haemodialysis: An updated systematic review

Purpose:

Early cannulation grafts are specifically designed for dialysis, whereas standard expanded polytetrafluoroethylene grafts were not. There is developing collective experience and literature available to allow the assessment of outcomes of these early cannulation grafts. The aim of this review was to review the evidence for both short- and long-term outcomes of early cannulation grafts.

Methods:

Using standardized searches of electronic databases in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses, the primary outcomes for this study were primary and secondary patency rates for early cannulation grafts for dialysis at 12 months and beyond. Secondary outcomes were timing of first cannulation, rates of access thrombosis, steal syndrome, pseudo-aneurysm and infection.

Results:

A total of 19 studies were identified and included. These were divided into different graft types. Flixene™, Avflo™, Acuseal™ and Vectra™ grafts all showed that early cannulation within 72 h is possible. Twelve-month pooled primary and secondary patency rates were 43.3% (95% confidence interval: 31.6–55.4) and 73.4% (95% confidence interval: 63–82.7) for the Flixene graft, 58.2% (95% confidence interval: 48–68.1) and 79.2% (95% confidence interval: 68–88.7) for the Avflo graft, 43.6% (95% confidence interval: 30.7–56.9) and 70.5% (95% confidence interval: 49.7–87.8) for the Acuseal graft and 63.7% (95% confidence interval: 53.4–73.4) and 85.8% (95% confidence interval: 82.9–88.4) for the Vectra graft. Data for outcome beyond 12 months were limited to the more recent studies.

Conclusion:

This review confirms that early cannulation is not detrimental on the early outcome of early cannulation graft patencies. It has also shown that both Vectra and Avflo grafts have adequate long-term patencies. The data do not allow specific graft recommendations, as comparative trials would be required.

Improved Patency of ePTFE Grafts as a Hemodialysis Access Site by Seeding Autologous Endothelial Cells Expressing Fibulin-5 and VEGF

Small caliber synthetic vascular grafts used for dialysis access sites have high failure rates due to neointima formation and thrombosis. Seeding synthetic grafts with endothelial cells (ECs) provides a biocompatible surface that may prevent graft failure. We tested the use of ePTFE grafts seeded with autologous ECs expressing fibulin-5 and vascular endothelial growth factor (VEGF), as a dialysis access site in a porcine model. We connected the carotid arteries and jugular veins of 12 miniature pigs using 7-mm ePTFE grafts; five grafts were seeded with autologous venous ECs modified to express fibulin-5 and VEGF, and seven unseeded grafts were implanted at the same location and served as controls. At 6 months, after completion of angiography, the carotid arteries and jugular veins with the connecting grafts were excised and fixed. Autologous EC isolation and transduction and graft seeding were successful in all animals. At 3 months, 4 of 5 seeded grafts and 3 of 7 control grafts were patent. At 6 months, 4 of 5 (80%) seeded grafts and only 2 of 7 (29%) control grafts were patent. Seeding ePTFE vascular grafts with genetically modified ECs improved long term small caliber graft patency. The biosynthetic grafts offer a novel therapeutic modality for vascular access in hemodialysis.

Prevalence and correlates of central venous catheter use among haemodialysis patients in the Irish health system - a national study

Background

Central venous catheters (CVC) are associated with substantial morbidity and mortality among patients undergoing haemodialysis (HD), yet they are frequently used as the primary vascular access for many patients on HD. The goal of this study was to determine the prevalence and variation in CVC use across centres in the Irish health system.

Methods

Data from the National Kidney Disease Clinical Patient Management System (KDCPMS) was used to determine CVC use and patterns across centres. Data on demographic characteristics, primary cause of end-stage kidney disease (ESKD), comorbid conditions, laboratory values and centre affiliation were extracted for adult HD patients (n = 1, 196) who were on dialysis for at least three months up to end of December 2016. Correlates of CVC use were explored using multivariable logistic regression.

Results

Overall prevalence of CVC use was 54% and varied significantly across clinical sites from 43% to 73%, P < 0.001. In multivariate analysis, the likelihood of CVC use was lower with increasing dialysis vintage, OR 0.40 (0.26–0.60) for 4 years vs 1 year vintage, rising serum albumin, OR 0.73 (0.59–0.90) per 5 g/L), and with cystic disease as a cause of ESKD, OR 0.38 (95% CI 0.21–0.6). In contrast, catheter use was greater for women than men, OR 1.77 (1.34–2.34) and for 2 out of 10 regional dialysis centres, OR 1.98 (1.02–3.84) and OR 2.86 (1.67–4.90) respectively compared to referent group).

Conclusions

Catheters are the predominant type of vascular access in patients undergoing HD in the Irish health system. Substantial centre variation exists which is not explained by patient-level characteristics.

Electronic supplementary material

The online version of this article (10.1186/s12882-018-0873-x) contains supplementary material, which is available to authorized users.