Home haemodialysis in the Netherlands: State of the art.

Home haemodialysis (HHD) has gained popularity in recent years, due to improved clinical outcomes associated with frequent or prolonged haemodialysis sessions, best achievable at home. However, several barriers to HHD are perceived by the physician and patient, among which lack of experience and education, logistic difficulties and reimbursement issues seem to be the most important ones. HHD, in particular when performed with intensified frequency or duration, is associated with improved quality of life, blood pressure control and survival. Serious adverse events are rare; however, more vascular access complications arise due to frequent needling. This emphasises the importance of comprehensive education and training. This review aims to provide the physician with a detailed state of the art overview on HHD in the Netherlands, discussing potential barriers and benefits, and offering practical advice.

Unraveling the relationship between mortality, hyponatremia, inflammation and malnutrition in hemodialysis patients: results from the international MONDO initiative.

BACKGROUND/OBJECTIVES: Hyponatremia is a risk factor for mortality in hemodialysis (HD) patients. It is not well known to which extent the comorbidities, malnutrition, fluid status imbalance and inflammation are related to hyponatremia and affect outcomes. SUBJECTS/METHODS: We studied 8883 patients from the European subset of the international MONitoring Dialysis Outcomes initiative. Nutritional and fluid statuses were assessed by bioimpedance spectroscopy. Fluid depletion was defined as overhydration⩽-1.1 l and fluid overload as overhydration>+1.1 l, respectively. Malnutrition was defined as a lean tissue index below the 10th percentile of age- and gender-matched healthy controls. Hyponatremia and inflammation were defined as serum sodium levels <135 mEq/l and C-reactive protein levels>6.0 mg/l, respectively. We used logistic regression to test for predictors of hyponatremia and Cox proportional hazards analysis to assess the association with all-cause mortality. RESULTS: Hyponatremia was predicted by the presence of malnutrition (odds ratio (OR)=1.49 (95% confidence interval (CI)=1.30-1.70), inflammation (OR=1.44 (95% CI=1.26-1.64)) and fluid overload ((>+1.1 l to +2.5 l) OR=0.73 (95% CI=0.62-0.85)) but not by fluid depletion (OR=1.34 (95% CI=0.92-1.96)). Malnutrition, inflammation, fluid overload, fluid depletion and hyponatremia (hazard ratio=1.70 (95% CI=1.46-1.99)) were independent predictors for all-cause mortality. CONCLUSIONS: In HD patients, hyponatremia is associated with malnutrition, inflammation and fluid overload. Hyponatremia maintained predictive for all-cause mortality after adjustment for malnutrition, inflammation and fluid status abnormalities. The presence of hyponatremia may assist in identifying HD patients at increased risk of death.

Association between pre hemodialysis serum sodium concentration and blood pressure: results from a retrospective analysis from the international monitoring dialysis outcomes (MONDO) initiative.

A recent study from the United Kingdom indicates an association between pre hemodialysis (HD) serum sodium (SNa(+)) and systolic and diastolic blood pressure (SBP and DBP) in chronic HD patients. We extend this analysis to an international cohort of incident HD patients. The Monitoring Dialysis Outcomes initiative encompasses patients from 41 countries. Over 2 years monthly pre-HD SNa(+) levels were used as predictors of pre-HD SBP and DBP in a linear mixed model (LMM) adjusted for age, gender, interdialytic weight gain, diabetes, serum albumin and calcium. Similar models were constructed with DBP as outcome. Analyses were carried out stratified by continent (North and South America; Europe and Asia). LMMs were also constructed for the entire observation period of 2 years, and separately the first and the second year after HD initiation. We studied 17 050 incident patients and found SNa(+) to have a significant slope estimate in the LMM predicting pre-HD SBP and DBP (ranging from 0.22 to 0.29 and 0.10 to 0.21 mm Hg per mEq l(-1), respectively, between the continents). The findings were similar in subsets of SBP and SNa(+) tertiles, and separately analyzed for the first and second year. Our analysis shows an independent association between SNa, SBP and DBP in a large intercontinental database, indicating that this relation is a profound biological phenomenon in incident and prevalent HD patients, generalizable to an international level and independent of SBP and DBP magnitude.

Cost-effectiveness of vascular access for haemodialysis: arteriovenous fistulas versus arteriovenous grafts.

BACKGROUND: The use of an arteriovenous fistula (AVF) for haemodialysis treatment may be associated with a high early failure rate, but usually good long-term patency, while using an arteriovenous graft (AVG) yields a lower early failure rate with worse long-term patency. The aim of this study was to calculate and compare the costs and outcome of AVF and AVG surgery in terms of early and long-term patencies. METHODS: A decision tree and a Markov model were constructed to calculate costs and performance of AVFs and AVGs. The model was populated with a retrospective cohort of HD patients receiving their first VA. The outcomes were determined probabilistically with a 5-year follow-up. RESULTS: AVFs were usable for a mean (95% CI) of 28.5 months (24.6-32.5 months), while AVGs showed a patency of 25.5 months (20.0-31.2 months). The use of AVFs was the dominant type of VA and € 631 could be saved per patient/per month patency compared to AVG use. Regardless of the willingness to pay, the use of AVFs yielded a higher probability of being cost-effective compared to AVGs. CONCLUSIONS: AVFs are more cost-effective than AVGs. Nonetheless, early failure rates significantly influence AVF performance and initiatives to reduce early failure can improve its cost-effectiveness.

Peritoneal dialysis in patients with heart failure.

Both in dialysis patients and non-uremic patients heart failure is associated with an adverse prognosis. In a state of abrupt worsening of cardiac function, acute cardiogenic shock or decompensated congestive heart failure, acute kidney injury may occur, whereas in a more chronic worsening of cardiac function chronic kidney injury may occur. Recently, the term cardiorenal syndrome was adopted and defined as "a pathophysiological disorder of the heart and kidneys whereby acute or chronic dysfunction in one organ may induce acute or chronic dysfunction in the other organ". Despite better treatment techniques and the continuous development of new medications volume overload in patients with cardiorenal syndrome is difficult to treat. Especially treatment of cardiorenal syndrome type I and II is notoriously difficult. Peritoneal dialysis might be, because of the gradual fluid removal, a therapeutic option in these patients. However, data on the effect of peritoneal dialysis in patients with heart failure with fluid overload and/or renal impairment are scarce. In this review, the role of peritoneal dialysis in the treatment cardiorenal syndrome type I, II and IV will be discussed.

Feasibility of non-contrast-enhanced magnetic resonance angiography for imaging upper extremity vasculature prior to vascular access creation.

OBJECTIVES: Preoperative mapping of arterial and venous anatomy helps to prevent postoperative complications after vascular access creation. The use of gadolinium in contrast-enhanced (CE) magnetic resonance angiography (MRA) has been linked to nephrogenic systemic fibrosis in patients with end-stage renal disease (ESRD). The purpose of this study was to evaluate non-contrast-enhanced (NCE) MRA for assessment of upper extremity and central vasculature and to compare it with CE-MRA. METHODS: NCE and CE-MRA images were acquired in 10 healthy volunteers and 15 patients with ESRD. In each data set, two observers analysed 11 arterial and 16 venous segments with regard to image quality (0-4), presence of artefacts (0-2) and vessel-to-background ratio. RESULTS: More arterial segments were depicted using CE-MRA compared to NCE-MRA (99% vs. 96%, p = 0.001) with mean image quality of 3.80 vs. 2.68, (p < 0.001) and mean vessel-to-background ratio of 6.47 vs. 4.14 (p < 0.001). Ninety-one percent of the venous segments were portrayed using NCE-MRA vs. 80% using CE-MRA (p < 0.001). Mean image quality and vessel-to-background ratio were 2.41 vs. 2.21 (p = 0.140) and 5.13 vs. 3.88 (p < 0.001), respectively. CONCLUSIONS: Although arterial image quality and vessel-to-background ratios were lower, NCE-MRA is considered a feasible alternative to CE-MRA in patients with ESRD who need imaging of the upper extremity and central vasculature prior to dialysis access creation.

Management of encapsulating peritoneal sclerosis: a guideline on optimal and uniform treatment.

Encapsulating peritoneal sclerosis (EPS) represents a rare complication of long-term peritoneal dialysis (PD). It is characterised by diffuse peritoneal membrane fibrosis, progressive intestinal encapsulation and the clinical spectrum of intestinal obstruction. The pathogenesis is as yet not well understood but includes inflammation, angiogenesis and fibrosis. The current diagnosis of EPS lacks specificity and relies on clinical, radiographic or macroscopic evaluation. There is no general agreement on managing EPS although accumulating clinical data suggest drug treatment (steroids, tamoxifen), surgery (enterolysis) or a combination of both. Here, we provide a short overview on the current knowledge of EPS, with a focus on treatment. Moreover, we present a diagnostic and a therapeutic algorithm for EPS based on the best available published data and our combined experience.

Peritoneal dialysis in patients with primary cardiac failure complicated by renal failure.

BACKGROUND/AIMS: Clinical outcome in cardiorenal syndrome type II and treated with peritoneal dialysis (PD). METHODS: Retrospective analysis over a period of 10 years. RESULTS: Twenty-four patients with mean age at start of dialysis of 67 ± 10 years had mean survival on dialysis of 1.03 ± 0.84 years (median survival 1.0 year). The number of hospitalizations for cardiovascular causes were reduced (13.7 ± 26.5 predialysis vs. 3.5 ± 8.8 days/patient/month postdialysis, p = 0.001). Patients who survived longer than the median survival time (n = 12) also had a reduced number of hospitalizations for all causes (3.7 ± 3.8 predialysis vs. 1.4 ± 2.1 days/patient/month postdialysis, p = 0.041), a lower age (62 ± 10 vs. 71 ± 8 years, p = 0.013) and fewer had diabetes (2 vs. 7 patients, p = 0.039), but left ventricular ejection fraction was not different. CONCLUSION: After starting PD for cardiorenal syndrome, hospitalizations for cardiovascular causes were reduced for all patients. Survival after starting PD is highly variable. Age and diabetes seem to be significant prognostic factors, but not left ventricular ejection fraction.

Surgical techniques to improve cannulation of hemodialysis vascular access.

OBJECTIVE: Successful access cannulation is of utmost importance for adequate hemodialysis treatment. Upper arm fistulae, obesity and deep or tortuous veins may impair needling and can cause significant complications and inconvenience for the patient. In the ultimate case, cannulation problems lead to temporary central vein catheter use for dialysis or even to irreversible access loss. Surgical access revision may enhance successful cannulation. METHODS: A systematic literature review of all publications related to hemodialysis vascular access, cannulation complications and treatment was performed. RESULTS: A total of 384 publications were identified, of which only 17 were related to treatment of cannulation complications in large patient populations. The clinical success rate of surgical intervention with vein elevation or transposition ranges from 85% to 91%. The 1-year primary and secondary patencies are 60% and 71%, respectively. Lipectomy results in an initial success rate of 100% with a primary and secondary patency of 71% and 98%, respectively, after 1 year of follow-up. CONCLUSION: Surgical revision to improve hemodialysis vascular access cannulation has a high clinical success rate with good long-term patency.

Patients' representations of their end-stage renal disease: relation with mortality.

BACKGROUND: Self-regulation theory explains how patients' illness perceptions influence self-management behaviour (e.g. via adherence to treatment). Following these assumptions, we explored whether illness perceptions of ESRD-patients are related to mortality rates. METHODS: Illness perceptions of 182 patients participating in the NECOSAD-2 study in the period between December 2004 and June 2005 were assessed. Cox proportional hazard models were used to estimate whether subsequent all-cause mortality could be attributed to illness perception dimensions. RESULTS: One-third of the participants had died at the end of the follow-up. Mortality rates were higher among patients who believed that their treatment was less effective in controlling their disease (perceived treatment control; RR = 0.71, P = 0.028). This effect remained stable after adjusting for sociodemographic and clinical variables (RR = 0.65, P = 0.015). CONCLUSIONS: If we consider risk factors for mortality, we tend to rely on clinical parameters rather than on patients' representations of their illness. Nevertheless, results from the current exploration may suggest that addressing patients' personal beliefs regarding the effectiveness of treatment can provide a powerful tool for predicting and perhaps even enhancing survival.

Contrast-enhanced magnetic resonance angiography findings prior to hemodialysis vascular access creation: a prospective analysis.

PURPOSE: To determine prospectively the clinical value of contrast-enhanced magnetic resonance angiography (CE-MRA) for assessment of the arterial inflow and venous outflow prior to vascular access (VA) creation. METHODS: Seventy-three patients underwent duplex ultrasonography (DUS) and CE-MRA prior to VA creation for detection of stenoses and occlusions. Two observers read the CE-MRA images for determination of inter-observer agreement. A VA was considered functional if it could be used for successful two-needle hemodialysis therapy within 2 months after creation. RESULTS: CE-MRA detected 6 stenosed, 8 occluded arterial vessel segments and 12 stenosed and 41 occluded venous vessel segments in 70 patients. Inter-observer agreement for detection of upper extremity arterial and venous stenoses and occlusions with CE-MRA was substantial to almost perfect (kappa values 0.76-0.96). CE-MRA detected lesions, not detected by DUS, that were associated with VA early failure and non-maturation in 33% of patients (7/21). Accessory veins detected preoperatively were the cause of VA non-maturation in a substantial group of patients (47%: 7/15). CONCLUSION: CE-MRA enables accurate detection of upper extremity arterial and venous stenosis and occlusions prior to VA creation. Preoperative CE-MRA identified arterial and venous stenoses, not detected by DUS that were associated with VA early failure and non-maturation. However, the use of gadolinium containing contrast media is currently contraindicated due the reported incidence of nephrogenic systemic fibrosis.

Prospective evaluation of ischemia in brachial-basilic and forearm prosthetic arteriovenous fistulas for hemodialysis.

UNLABELLED: Ischemia is a devastating complication after arteriovenous fistula (AVF) creation. When not timely corrected, it may lead to amputation. Symptomatic ischemia occurs in 3.7-5% of the hemodialysis population. Upper arm AVFs have a higher incidence of ischemia compared to forearm AVFs. As more patients may need upper arm AVFs in the growing and older hemodialysis population, occurrence of symptomatic ischemia may increase. The purpose of this study is to identify predictors for occurrence of ischemia. METHODS: A prospective evaluation of ischemia was performed in patients randomised for either a brachial-basilic (BB-) AVF or a prosthetic forearm loop AVF. Clinical parameters, preoperative vessel diameters, access flows, digital blood pressures, digit-to-brachial indices (DBI) and interventions for ischemia were recorded. RESULTS: Sixty-one patients (BB-AVF 28) were studied. Seventeen patients (BB-AVF 8) developed ischemic symptoms. Six patients (BB-AVF 3) needed interventions for severe symptoms. Age, history of peripheral arterial reconstruction and radial artery volume flow were significant predictors for the occurrence of ischemia. CONCLUSION: Symptomatic ischemia occurred in 28% of patients with brachial-basilic and prosthetic forearm AVFs. Age, history of peripheral arterial reconstruction and radial artery volume flow might be important for prediction of ischemia.

Accessory veins and radial-cephalic arteriovenous fistula non-maturation: a prospective analysis using contrast-enhanced magnetic resonance angiography.

PURPOSE: To determine if large caliber accessory veins are associated with radial-cephalic arteriovenous fistula (RC-AVF) non-maturation. METHODS: RC-AVFs were created in 15 consecutive patients (radial artery and cephalic vein diameter > 2 mm, in the absence of arterial inflow or venous outflow stenoses or occlusions). Contrast-enhanced magnetic resonance angiography (CE-MRA) was performed preoperatively for the determination of vessel diameters, stenoses and occlusions. The location and caliber of accessory veins was determined. Vascular access (VA) function was monitored and all interventions required to obtain a functioning VA were recorded. Non-maturation was defined as a nonfunctional VA at 2 months after creation. The predictive value of accessory vein caliber for prediction of RC-AVF non-maturation was evaluated using receiver operating characteristic (ROC) analysis. RESULTS: Non-maturation occurred in 10 (67%) out of 15 RC-AVFs. Large caliber accessory veins (n = 4), venous stenosis (n = 3) or both (n = 2) were associated with RC-AVF non-maturation. The presence of large caliber accessory veins was the only significant predictor for RC-AVF non-maturation (p = 0.01). Preoperatively detected accessory veins with a diameter > 70% of the cephalic vein diameter, had a sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 80, 100, 100 and 91% for prediction of RC-AVF non-maturation on patient level. Accessory vein ligation and dilatation of venous stenosis resulted in an overall salvage success rate of 89% (8/9). CONCLUSION: Large caliber accessory veins are associated with RC-AVF non-maturation. Ligation of large caliber accessory veins is a successful salvage procedure in a substantial group of patients. Furthermore, ligation of these accessory veins during initial RC-AVF creation can potentially reduce non-maturation rates; and therefore, preoperative assessment of accessory veins is recommended.

Effect of upper arm brachial basilic and prosthetic forearm arteriovenous fistula on left ventricular hypertrophy.

BACKGROUND: Creation of an arteriovenous fistula (AVF) may increase left ventricular hypertrophy in the hemodialysis population. Aim of this study was to compare the effects of a brachial-basilic (BB) AVF and the prosthetic brachial-antecubital forearm loop access (PTFE) on cardiac performance. METHODS: Patients were randomized to receive BB-AVF or prosthetic brachial-antecubital forearm loop access. Before and three months after AVF creation patients underwent an echocardiographic examination. Mann-Whitney U-test was used to compare relative increase between the measured cardiac parameters for the two groups. RESULTS: Twenty-seven patients participated in the study. The relative increase in left ventricular parameters was not significantly different between the two groups. Only left ventricular end-diastolic diameter tended to be of significance. Mean blood flow through the brachial artery was 1680+/-156 and 1450+/-221 mL/min three months after surgery for the PTFE and the BB-AVF group, respectively. CONCLUSION: After three months of follow-up, changes in cardiac structure were comparable between patients with BB and PTFE AVFs. Also access flow was comparable at this time. In general, the effects of creation of a fistula on LV structure were limited. Longer follow up time may be needed to explore the long term effects of different vascular accesses on cardiac function.

Access flow measurement by indicator dilution without indicator injection: effect of switch location.

It is well known that the measurement of access flow by one of the various dilution techniques requires the reversal of blood flow drawn from and returned to the peripheral vascular access. But it was only recently recognized that the line switch itself constitutes a dilution experiment for certain blood and dialysate components and properties, so that a subsequent injection of indicator is no longer required. New switches introduced at different locations in the extracorporeal circulation not only simplify manual operation for standard access flow measurement but also provide an essential tool for the new technique, which is based on continuously measuring certain blood and/or dialysate characteristics and their changes caused by switching the bloodlines. In this study, the effects of switching the bloodlines at two different locations were studied when extracorporeal temperatures were used as a marker. The study shows that the temperature changes depend on the location of the switch relative to the extracorporeal temperature sensors, and that different algorithms to calculate access flow have to be used for the two possible switching positions to account for this dependence.

Measurement of hemodialysis vascular access flow using extracorporeal temperature gradients.

A reduction in vascular access flow poses a risk for thrombosis. We present a new technique to measure vascular access flow during dialysis based on extracorporeal temperature gradients, and their changes, on reversing the extracorporeal bloodlines without having to inject an indicator. Fistula temperatures were measured by the blood temperature monitor with normal line position and after manual switching of the bloodlines using the same extracorporeal blood flow. The access flow by our temperature gradient method (TGM) was compared to access flow derived by saline dilution with measurements in the same patients repeated in subsequent weeks. In 70 pairs of TGM and saline dilution measurements in 35 patients, the repeatability of the TGM measurements was not significantly different from that of saline dilution. There was a highly significant correlation between the two techniques with an acceptable confidence level for limits of agreement for the difference between them. It took about 9 min to complete the TGM method and about 5 min for saline dilution. Our studies show that the novel TGM method showed excellent agreement and reproducibility with the saline dilution method without the need for indicator dilution.

Implementation of a vascular access quality programme improves vascular access care.

INTRODUCTION: In the Netherlands an access quality improvement plan (QIP) was introduced by vascular access coordinators (VAC) with the aim to decrease vascular access-related complications by preemptive intervention of malfunctioning accesses. A vascular access QIP was established in 24 centres (46% of all Dutch facilities) and a structural multidisciplinary vascular access meeting was instituted. In these centres, including 2300 patients, a protocol for enhancement of fistula creation and access surveillance programme was implemented, with instruction of physicians and nurses, and rounds to discuss complications and evaluate vascular access interventions. The number and type of vascular access, permanent catheters, thrombosis rates and number of interventions were evaluated at the start and end of the study period. RESULTS: After the surveillance programme, the number of autogenous arterio-venous fistulas (AVFs) had increased significantly from 69 to 77% (P < 0.01), while the use of temporary subclavian vein catheters declined (34% vs 11%) (P < 0.01), with a substantially higher percentage of jugular vein catheters (from 23 to 35%). Interventional treatment of malfunctioning accesses by percutaneous transluminal angioplasty (PTA) (from 0.39 to 0.50 patient/year; P < 0.001)) and surgical revisions (from 0.06 to 0.12 per patient/year; P < 0.001) also increased. CONCLUSION: These data demonstrate that a vascular access QIP resulted in placement of more autogenous AVFs, increased number of PTAs and surgical interventions. These findings suggest that a vascular access care QIP is worthwhile to improve dialysis patients' care and access morbidity.

Association of serum fetuin-A levels with mortality in dialysis patients.

Calcifying atherosclerosis is an active process, which is controlled by calcification inhibitors and inducers. Fetuin-A, an acute phase glycoprotein, is one of the more powerful circulating inhibitors of hydroxyapatite formation. A prospective multicenter cohort study was initiated to include both hemodialysis (HD) and peritoneal dialysis (PD) patients in an evaluation of the association of serum fetuin-A levels with both cardiovascular (CV) and non-CV mortality. An increase in the serum fetuin-A concentration of 0.1 g/l was associated with a significant reduction in all-cause mortality of 13%. There was a significant 17% reduction in non-CV mortality and a near significant reduction in CV mortality. This association of fetuin-A and mortality rates was comparable in both HD and PD patients even when corrected for factors, including but not limited to age, gender, primary kidney disease, C-reactive protein levels, and nutritional status. We conclude that serum fetuin-A concentrations may be a general predictor of mortality in dialysis patients.