Overview of regular dialysis treatment in Japan (as of 31 December 2008)

Current dialyzer classification in Japan and mortality risk in patients undergoing hemodialysis

Dialyzers are classified into five types based on their β2-microglobulin clearance rate and albumin sieving coefficient: Ia, Ib, IIa, and IIb. In addition, a new classification system introduced a type S dialyzer. However, limited information is available regarding the impact of dialyzer type on patient outcomes. A cohort study was conducted using data from the Japanese Society for Dialysis Therapy Renal Data Registry database. Total 181,804 patients on hemodialysis (HD) were included in the study, categorized into four groups (type Ia, IIa, IIb, and S). The associations between each group and two-year all-cause mortality were assessed using Cox proportional hazard models. Furthermore, propensity score-matching analysis was performed. By the end of 2019, 34,185 patients on dialysis had died. After adjusting for all confounders, the risk for all-cause mortality was significantly lower in the type IIa, and S groups than in the type Ia group. These significant findings were consistent after propensity score matching. In conclusion, our findings suggest that super high-flux dialyzers, with a β2-microglobulin clearance of ≥ 70 mL/min, may be beneficial for patients on HD, regardless of their albumin sieving coefficient. In addition, type S dialyzers may be beneficial for elderly and malnourished patients on dialysis.Trial registration number: UMIN000018641.

Birth cohort effects in incident renal replacement therapy in Japan, 1982-2021

BACKGROUND

This study aimed to investigate the long-term trends of incident end-stage kidney disease (ESKD) requiring renal replacement therapy (RRT) in Japan using age-period-cohort analysis and evaluated birth cohort effects for incident ESKD requiring RRT.

METHODS

The number of incident RRT patients aged between 20 and 84 years by sex from 1982 to 2021 was extracted from the Japanese Society of Dialysis Therapy registry data. Annual incidence rates of RRT were calculated using census population as denominators, and changes in the incidence rates were evaluated using an age-period-cohort model. The age and survey year period categories generated 20 birth cohorts with 5-year intervals (from 1902-1907 to 1997-2001).

RESULTS

The incidence rates of RRT in both sexes initially rose in the birth cohorts born in the early 1900s, and then decelerated and peaked during 1940-1960s in men and 1930-1940s in women, following a steady decline in both sexes. Compared with the reference 1947-1951 birth cohort, the highest cohort rate ratio was 1.14 (95% CI, 1.04-1.25) in the 1967-1971 birth cohort in men and 1.04 (95% CI, 0.98-1.10) in the 1937-1941 birth cohort in women.

CONCLUSIONS

Significant cohort effects were identified in both sexes, but the peak of RRT was different for each sex. Our findings suggest that men born between 1940 and 1960s and women born between 1930 and 40 s may be important target populations to consider when decreasing incidence rates of RRT among the general Japanese population.

Kidney transplant access for children and young adults with congenital anomalies of the kidney and urinary tract

PURPOSE

Although congenital anomalies of the kidney and urinary tract (CAKUT) are among the leading causes of end-stage kidney disease (ESKD) in children and young adults, kidney transplantation access for this population has not been well studied in the US. We compared transplantation access in the US based on whether the etiology of kidney disease was secondary to CAKUT, and additionally by CAKUT subgroups (anatomic vs. inherited causes of CAKUT).

METHODS

Using the United States Renal Data System, we conducted a retrospective cohort study of 80,531 children and young adults who started dialysis between 1995 and 2015. We used adjusted Cox models to examine the association between etiology of kidney disease (CAKUT vs. non-CAKUT, anatomic vs. inherited) and receipt of kidney transplantation, and secondarily, receipt of a living vs. deceased donor kidney transplant.

RESULTS

Overall, we found an increased likelihood of kidney transplantation access for participants with CAKUT compared to those without CAKUT (HR 1.23; 95% CI 1.20-1.27). Among the subset of individuals with CAKUT as the attributed cause of ESKD, we found a lower likelihood of kidney transplantation in those with anatomic causes of CAKUT compared to those with inherited causes of CAKUT (adjusted HR 0.85; 0.81-0.90).

CONCLUSION

There are notable disparities in kidney transplantation rates among CAKUT subgroups. Those with anatomic causes of CAKUT started on dialysis have significantly reduced access to kidney transplantations compared to individuals with inherited causes of CAKUT who were initiated on dialysis. Further studies are needed to understand barriers to transplantation access in this population.

Usefulness of a Novel Vascular Access Management Method Using a Laser Blood Flowmeter

INTRODUCTION

Various methods for vascular access (VA) management have been studied. We investigated the usefulness of a new, simple, and quantitative VA management method using the Pocket LDF® laser blood flowmeter (hereinafter "LDF") that noninvasively measures peripheral circulation flow.

METHODS

Peripheral circulation flow was measured in 82 patients (43 men) on maintenance hemodialysis with an arteriovenous fistula (AVF). The shunt symmetry index (SSI) was calculated as peripheral circulation flow in the AVF limb divided by that in the non-AVF limb. SSI was used for microcirculation evaluation and also compared by AVF site. Patients undergoing vascular access interventional therapy (VAIVT) underwent ultrasound evaluation (Doppler ultrasonography) of the AVF and SSI measurement before and after VAIVT. SSI was compared between those who did and did not require VAIVT, and the cutoff value for SSI was determined by receiver operating characteristic curve (ROC) analysis.

RESULTS

As many as 86% of the patients who were measured peripheral circulation flow had SSI <1.0, which indicates that AVF reduced peripheral circulation flow. All patients who underwent VAIVT showed a decrease in SSI to <1.0 after VAIVT, probably due to improvement of stenosis. SSI differed significantly between patients who did and did not require VAIVT (1.20 ± 0.49 vs. 0.65 ± 0.33, p < 0.001), which indicates that SSI is affected by the presence of stenosis in the proximal vein of the VA anastomosis. In patients with SSI ≥1.0, stenosis of the proximal vein of the AVF caused stasis of blood flow, resulting in increased peripheral blood flow. AVF site seems to have no impact on peripheral circulation flow. The SSI cutoff value for the screening of proximal vein stenosis was 1.06 (sensitivity: 0.69, specificity: 0.93, area under the curve: 0.81).

CONCLUSION

Based on the ROC analysis, we recommend considering AVF ultrasound for SSI >1.06. Our results suggest the usefulness of the described VA management method using the LDF.

Lethal ventricular arrhythmia can be prevented by adjusting the dialysate potassium concentration and the use of anti-arrhythmic agents: a case report and literature review

Background

Hypokalemia is common in patients with malnutrition undergoing hemodialysis and is often involved in the development of lethal arrhythmia. Moreover, hemodialysis therapy decreases the serum potassium concentration due to potassium removal to the dialysate. However, it is difficult to adjust the dialysate potassium concentration owing to the use of the central dialysate delivery system in Japan. Here, we have presented a case undergoing hemodialysis with dialysate potassium concentration adjustment to prevent ventricular arrhythmia.

Case presentation

A 56-year-old man with Emery-Dreifuss muscular dystrophy and chronic heart failure was admitted to our hospital and needed subsequent hemodialysis therapy due to renal dysfunction. During hemodialysis, the cardiac resynchronization therapy defibrillator was activated to the treatment of his lethal ventricular arrhythmia. Decreases in serum potassium concentration after hemodialysis and changes in serum potassium concentration during HD were considered the causes of lethal ventricular arrythmia. Therefore, along with using anti-arrhythmic agents, the dialysate potassium concentration was increased from 2.0 to 3.5 mEq/L to minimize changes in the serum potassium concentration during hemodialysis. Post-dialysis hypokalemia disappeared and these changes during hemodialysis were minimized, and no lethal ventricular arrhythmia occurred thereafter.

Conclusions

In this case, we prevented lethal arrhythmia by maintaining the serum potassium concentration by increasing the dialysate potassium concentration, in addition to the use of anti-arrhythmic agents. In the acute phase of patients with frequent lethal arrhythmia undergoing hemodialysis, an increase in dialysate potassium concentration may be an effective method for preventing arrhythmogenic complications.

Impact of Hemodialysis on Clinical Outcomes in Patients Undergoing Lower Extremity Bypass Surgery for Peripheral Artery Disease-10-year Follow-Up Study

We investigated the clinical impact of hemodialysis on long-term outcomes of bypass surgery in patients with peripheral artery disease. We evaluated 660 consecutive patients who underwent successful bypass surgery (392 hemodialysis and 268 non-hemodialysis). The endpoint was amputation-free survival (AFS). To minimize differences in clinical characteristics between the 2 groups, propensity score matching was performed. The AFS rates for 10-year follow-up were 39.3% and 67.7% in hemodialysis and non-hemodialysis patients [hazard ratio (HR) 2.21, 95% confidence interval (CI) 1.65-3.01, P < .0001]. Cumulative incidence of amputation was higher in the hemodialysis group than in the non-hemodialysis group [(19.4 vs 8.4%, HR 2.15, 95% CI 1.29-3.74, P = .0027). In a matched cohort (n = 210 each), AFS was still lower in the hemodialysis patients (53.1 vs 66.3%, HR 1.94, 95% CI 1.36-2.82, P = .0003). However, there was no significant difference in amputation rate between the groups (10.5 vs 10.6%, HR .97, 95% CI 0.49-1.87, P = .93). In a sub-analysis of patients with critical limb ischemia, similar results were obtained. The 10-year AFS was consistently lower in the hemodialysis group than in the non-hemodialysis group. However, the amputation rate was comparable between the groups when matched for the differences in clinical characteristics.

Brachial artery transposition versus catheters as tertiary vascular access for maintenance hemodialysis: a single-center retrospective study

Some hemodialysis patients are not suitable for creation of an arteriovenous fistula (AVF) or arteriovenous graft (AVG). However, they can receive a tunneled cuffed central venous catheter (tcCVC), but this carries risks of infection and mortality. We aimed to evaluate the safety and effectiveness of brachial artery transposition (BAT) versus those of tcCVC. This retrospective study evaluated hemodialysis patients who underwent BAT or tcCVC placement because of severe heart failure, hand ischemia, central venous stenosis or occlusion, inadequate vessels for creating standard arteriovenous access, or limited life expectancy. The primary outcome was whole access circuit patency. Thirty-eight patients who underwent BAT and 25 who underwent tcCVC placement were included. One-year patency rates for the whole access circuit were 84.6% and 44.9% in the BAT and tcCVC groups, respectively. The BAT group was more likely to maintain patency (unadjusted hazard ratio: 0.17, 95% confidence interval: 0.05–0.60, p = 0.006). The two groups did not have significantly different overall survival (log-rank p = 0.146), although severe complications were less common in the BAT group (3% vs. 28%, p = 0.005). Relative to tcCVC placement, BAT is safe and effective with acceptable patency in hemodialysis patients not suitable for AVF or AVG creation.

Sex differences in the 10-year survival of patients undergoing maintenance hemodialysis in the Q-Cohort Study

Women have a longer life expectancy than men in the general population. However, it has remained unclear whether this advantage is maintained in patients undergoing maintenance hemodialysis. The aim of this study was to compare the risk of mortality, especially infection-related mortality, between male and female hemodialysis patients. A total of 3065 Japanese hemodialysis patients aged ≥ 18 years old were followed up for 10 years. The primary outcomes were all-cause and infection-related mortality. The associations between sex and these outcomes were examined using Cox proportional hazards models. During the median follow-up of 8.8 years, 1498 patients died of any cause, 387 of whom died of infection. Compared with men, the multivariable-adjusted hazard ratios (95% confidence interval) for all-cause and infection-related mortality in women were 0.51 (0.45–0.58, P < 0.05) and 0.36 (0.27–0.47, P < 0.05), respectively. These findings remained significant even when propensity score-matching or inverse probability of treatment weighting adjustment methods were employed. Furthermore, even when the non-infection-related mortality was considered a competing risk, the infection-related mortality rate in women was still significantly lower than that in men. Regarding all-cause and infection-related deaths, women have a survival advantage compared with men among Japanese patients undergoing maintenance hemodialysis.

Super high-flux membrane dialyzers improve mortality in patients on hemodialysis: a 3-year nationwide cohort study

Introduction

In Japan, dialyzers are classified based on β₂-microglobulin clearance. Type I dialyzers are classified as low-flux dialyzers (<10 mL/min clearance), type II and III as high-flux dialyzers (≥10 to <30 mL/min and ≥30 to <50 mL/min clearance, respectively), and type IV and V as super high-flux dialyzers (≥50 to <70 mL/min and ≥70 mL/min clearance, respectively). Super high-flux dialyzers are commonly used, but their superiority over low-flux dialyzers is controversial.

Methods

In this nationwide prospective cohort study, we analyzed Japanese Society for Dialysis Therapy Renal Data Registry data collected at the end of 2008 and 2011. We enrolled 242,467 patients on maintenance hemodialysis and divided them into five groups by dialyzer type. We assessed the associations of each dialyzer type with 3-year all-cause mortality using Cox proportional hazards models and performed propensity score matching analysis, adjusting for potential confounders.

Results

By the end of 2011, 53,172 (21.9%) prevalent dialysis patients had died. Mortality significantly decreased according to dialyzer type. Hazard ratios (HRs) were significantly higher for type I, II and III compared with type IV (reference) after adjustment for basic factors and further adjustment for dialysis-related factors. HR was significantly higher for type I, but significantly lower for type V, after further adjustment for nutrition- and inflammation-related factors. These significant findings were also evident after propensity score matching.

Conclusions

Hemodialysis using super high-flux dialyzers might reduce mortality. Randomized controlled trials are warranted to clarify whether these type V dialyzers can improve prognosis.

New Estimation Formulas for Daily Sodium Intake in Hemodialysis Patients by a Duplicate Portion Method

OBJECTIVE

Excess sodium intake is associated with volume overload and increased blood pressure. Therefore, to prevent future cardiovascular events, a sodium-restricted diet is strongly recommended for patients on maintenance hemodialysis (HD). However, only one formula for estimating dietary sodium intake in HD patients is available, and its validity has not been adequately evaluated. This study aimed to measure daily sodium intake using the duplicate portion method and provide a new formula for estimating dietary sodium intake.

DESIGN AND METHODS

Nineteen Japanese patients undergoing HD were enrolled in this cross-sectional multicenter study. The daily sodium intake of these patients was measured directly using the duplicate portion method. Two formulas for estimating sodium intake were developed by stepwise regression analysis. Their validities were compared with the validity of the previous formula. Furthermore, using these new formulas, we estimated the daily consumption of sodium in a large number of Japanese HD patients.

RESULTS

The previous formula underestimated true sodium intake using Bland-Altman diagrams. No significant correlation was noted between the measured sodium intake and the estimated intake (r = 0.30, P = .23, Fisher's Z-transformation). The new formulas 1 and 2, which included age, predialysis and postdialysis serum sodium levels, predialysis body weight, and interdialytic body weight gain, accurately estimated sodium consumption. The coefficients of correlation between the estimated values and the true sodium intake were r = 0.858 and r = 0.805, respectively. The simulation model using data from the Japanese Society for Dialysis Therapy showed that the distribution of the estimated sodium intake using the previous formula shifted left compared with that using the new formulas.

CONCLUSIONS

The new formulas accurately estimated the daily sodium consumption in HD patients. Further longitudinal studies are required to determine whether the estimated sodium intake level calculated using the new formulas would serve as a potential marker and/or therapeutic target to prevent cardiovascular events in HD patients.

Impact of a change in vascular access flow volume after percutaneous transluminal angioplasty on cardiac function

Vascular access (VA) is necessary for patients on hemodialysis, and percutaneous transluminal angioplasty (PTA) is a useful treatment for maintaining VA function. PTA immediately increases the VA flow volume, which can affect cardiac function. We investigated the relationship between changes in VA flow volume and cardiac function in patients who underwent PTA. This was a single-center retrospective observational study, including patients who underwent PTA between June 2016 and August 2016. VA flow volume and cardiac function were measured by sonography before and 1 h after PTA. This study included 50 PTA procedures in 50 cases. PTA significantly increased the median VA flow volume from 445 (range, 150-1229) to 725 (350-1268) mL/min. Although the ejection fraction and diameter of the inferior vena cava were unchanged, the cardiac output (CO) and cardiac index increased significantly in most cases. Surprisingly, the CO was decreased in 18% of cases despite the increased VA flow volume. In this atypical group, a high CO before PTA was found to be a significant factor for the decrease in CO by PTA. In most cases, both VA flow volume and CO were increased by PTA, whereas in some cases, the CO was decreased despite an increase in VA flow volume. This atypical phenomenon may be due to the insufficient adaptive response in the peripheral artery and heart and could predict risks for future cardiac events. Therefore, it is important that such patients are carefully followed up on.

High-performance dialyzers and mortality in maintenance hemodialysis patients

Few data are available regarding the association of dialyzer type with prognosis. In Japan, dialyzers are classified as types I, II, III, IV, and V based on β₂-microglobulin clearance rates of < 10, < 30, < 50, < 70, and ≥ 70 mL/min, respectively. We investigated the relationship of the 5 dialyzer types with 1-year mortality. This nationwide cohort study used data collected at the end of 2008 and 2009 by the Japanese Society for Dialysis Therapy Renal Data Registry. We enrolled 203,008 patients on maintenance hemodialysis who underwent hemodialysis for at least 1 year and were managed with any of the 5 dialyzer types. To evaluate the association of dialyzer type with 1-year all-cause mortality, Cox proportional hazards models and propensity score-matched analyses were performed. After adjustment of the data with clinicodemographic factors, the type I, II, and III groups showed significantly higher hazard ratios (HRs) than the type IV dialyzers (reference). After adjustment for Kt/V and β₂-microglobulin levels, the HRs were significantly higher in the type I and II groups. After further adjustment for nutrition- and inflammation-related factors, the HRs were not significantly different between the type IV and type I and II groups. However, type V dialyzers consistently showed a significantly lower HR. With propensity score matching, the HR for the type V dialyzer group was significantly lower than that for the type IV dialyzer group. Additional long-term trials are required to determine whether type V dialyzers, which are high-performance dialyzers, can improve prognosis.

Multicentre Study on the Efficacy of Brachial Artery Transposition Among Haemodialysis Patients

OBJECTIVE

Brachial artery transposition (BAT) is not a well known method for obtaining vascular access (VA) for maintenance haemodialysis. This study evaluated the outcomes of BAT.

METHODS

This multicentre retrospective cohort study included 233 consecutive patients who underwent BAT between January 2012 and December 2013. The indications were inadequate vessels for obtaining VA, severe heart failure, hand ischaemia, central vein stenosis/occlusion, or a history of catheter/graft infection. The transposed brachial artery was used only for arterial inflow and other routes were used for outflow.

RESULTS

BAT was successful in 227 patients, and adequate blood flow was achieved during dialysis sessions. The first successful cannulation was after a median of 18 days. BAT was performed using superficial veins as the return route in 127 patients and arteriovenous fistula (AVF) creation in 63 patients to prevent maturation failure. In 41 patients with central venous catheterisation, the transposed brachial artery was used for arterial inflow. The complications of BAT were impaired wound healing in 14 patients, including skin necrosis in two; large aneurysms in six, including a mycotic pseudo-aneurysm in one; arterial thrombosis in five; hand ischaemia in five; lymphorrhoea in four; and haematoma/bleeding in three. The transposed brachial artery was abandoned in four, three, three, and one case of arterial thrombosis/stenosis, haematoma/bleeding, skin necrosis, and large aneurysm, respectively. Access to the return routes failed in 48 cases because of vein damage caused by cannulation in 22, AVF thrombosis/stenosis in 14, catheter infection in six, and catheter occlusion in six. At two years, the primary patency rates of the transposed brachial artery and access circuit were 88% and 54%, respectively.

CONCLUSION

BAT is a safe and effective technique. The patency was high for the transposed brachial artery but adequate for the access circuit. BAT can be considered for patients with an unobtainable standard arteriovenous access.

Relationship between intraoperative measured parameters of parathyroid gland and pathological patterns in patients with secondary hyperparathyroidism

Background

The hyperplastic patterns of parathyroid glands (PTGs) in secondary hyperparathyroidism (SHPT) are critical for surgical indication and deciding on the approach. Earlier histopathological investigations have suggested the occurrence of an initial increase in the parathyroid cells, with a normal lobular structure (diffuse hyperplasia, DH). After this, the PTGs become hyperplastic with some nodules (nodular hyperplasia, NH). The current study aimed to explore the relationship between the intraoperative measurements of weight, volume, and maximal diameter of dissected PTGs and the histopathological diagnosis of SHPT patients with end-stage renal disease.

Methods

A total of 182 SHPT patients who received parathyroidectomy (PTX) were retrospectively enrolled. Altogether 21 patients were selected as having at least one diffuse polyclonal hyperplasia PTG. Intraoperative measurements of weight, volume, and maximal diameter of dissected PTGs were compared between tissues with DH and NH.

Results

Intraoperative dissected PTGs were verified histologically. The differences in the intraoperative measurements of weight, volume, maximal diameter, and the combination of the three measurements between the DH and the NH PTGs groups were significant (P=0.000), and the values of area under the ROC curve (AUCs) were 0.824 (95% CI: 0.731–0.918), 0.812 (95% CI: 0.716–0.908), 0.746 (95% CI: 0.633–0.860), and 0.851 (95% CI: 0.768–0.935), respectively, with cut-off values of the three parameters being 0.19 g, 206.3 mm³, and 10.5 mm, respectively.

Conclusions

The measurement of weight, volume, and maximal diameter of dissected PTGs is a possible alternative to assess the hyperplasia patterns of the dissected PTGs. It is a promising reference for the ultrasound prediction of pathological patterns of PTGs.

Long-Term Prognosis of Hyperferritinemia Induced by Intravenous Iron Therapy in Patients Undergoing Maintenance Hemodialysis: A 10-Year, Single-Center Study

Optimal ferritin level in hemodialysis patients between Japan and other countries is controversial. Long-term side effects of iron supplementation in these patients remain unclear. We aimed to elucidate whether past hyperferritinemia in hemodialysis patients was associated with high risk of death and cerebrovascular and cardiovascular diseases (CCVDs). This small retrospective cohort study included approximately 44 patients unintentionally supplemented with excessive intravenous iron. A significantly higher risk of CCVDs was observed in patients with initial serum ferritin levels ≥1000 ng/mL than in the remaining patients. High ferritin levels slowly decreased to <300 ng/mL in a median of 24.2 (10.5–46.5) months without treatment. However, compared with the remaining patients, only patients whose ferritin levels did not decrease to <300 ng/mL steadily had a significantly higher risk of all-cause death (hazard ratio, 9.6). Long-term hyperferritinemia due to intravenous iron therapy is a risk factor for death in maintenance hemodialysis patients. For a prolonged better prognosis, intravenous iron should be carefully administered so as to avoid hyperferritinemia in patients with hemodialysis.

Pre-dialysis Hyponatremia and Change in Serum Sodium Concentration During a Dialysis Session Are Significant Predictors of Mortality in Patients Undergoing Hemodialysis

Background

Previous studies have shown that hyponatremia is associated with greater mortality in hemodialysis (HD) patients. However, there have been few reports regarding the importance of the change in serum sodium (SNa) concentration (ΔSNa) during dialysis sessions. To investigate the relationships of pre-dialysis hyponatremia and ΔSNa during a dialysis session with mortality, we analyzed data from a national registry of Japanese patients with end-stage kidney disease.

Methods

We identified 178,114 patients in the database who were undergoing HD 3 times weekly. The study outcome was 2-year all-cause mortality, and the baseline SNa concentrations were categorized into quintiles. We evaluated the relationships of SNa concentration and ΔSNa with mortality using Cox proportional hazards models.

Results

During a 2-year follow-up period, 25,928 patients died. Each 1-mEq/l reduction in pre-HD SNa concentration was associated with a cumulatively greater risk of all-cause mortality (hazard ratio [HR], 1.05; 95% confidence interval [CI], 1.05–1.06). In contrast, a larger ΔSNa was associated with higher all-cause mortality (HR for a 1-mEq/l increase in ΔSNa, 1.02; 95% CI 1.01–1.02). The combination of low pre-HD SNa concentration and large ΔSNa was also associated with higher mortality (HR 1.09; 95% CI 1.05–1.13). Participants with the lowest SNa concentration (≤136 mEq/L) and the highest ΔSNa (>4 mEq/L) showed higher mortality than those with an intermediate pre-HD SNa concentration (137–140 mEq/L) and the lowest ΔSNa (≤2 mEq/L).

Conclusions

Lower pre-HD SNa concentration and higher ΔSNa are associated with a greater risk of mortality in patients undergoing HD.

Association of normalized protein catabolic rate (nPCR) with the risk of bone fracture in patients undergoing maintenance hemodialysis: The Q-Cohort Study

BACKGROUND & AIMS

Normalized protein catabolic rate (nPCR) is used as a surrogate for daily dietary protein intake and nutritional status in patients receiving maintenance hemodialysis. It remains uncertain whether the nPCR level is associated with the incidence of bone fracture.

METHODS

A total of 2869 hemodialysis patients registered in the Q-Cohort Study, a multicenter, prospective, observational study, were followed up for 4 years. The primary outcome was bone fracture at any site. The main exposure was the nPCR level at baseline. Patients were assigned to four groups based on their baseline nPCR levels (G1: <0.85, G2: 0.85≤, <0.95, G3: 0.95≤, <1.05 [reference], G4: ≥1.05 g/kg/day). We examined the relationship between the nPCR levels and the risk for bone fracture using Cox proportional hazards models.

RESULTS

During the follow-up period, 136 patients experienced bone fracture at any site. In the multivariable analyses, the risk for bone fracture was significantly higher in the lowest (G1) and highest (G4) nPCR groups than the reference (G3) group (hazard ratio [95% confidence intervals]: G1, 1.93 [1.04-3.58]; G2, 1.27 [0.67-2.40]; G3 1.00 (reference); G4, 2.21 [1.25-3.92]). The association remained almost unchanged, even when patients were divided into sex-specific nPCR quartiles, when analysis was limited to patients with a dialysis vintage ≥2 years, assumed to have lost residual kidney function, or when a competing risk model was applied.

CONCLUSIONS

Our results suggest that both lower and higher nPCR levels are associated with an increased risk for bone fracture in hemodialysis patients.

In vivo evaluation of drug dialyzability in a rat model of hemodialysis

It is important to calculate the drug removal by hemodialysis (HD) for drug dosing regimens in HD patients. However, there are limited and inconsistent information about the dialyzability of drugs by HD. Therefore, the aim of our study is to evaluate drug removal by utilizing a rat model of HD (HD rat) and to extrapolate this result to the drug removal rate in HD patients. HD rats received bilateral nephrectomy and HD for 2 h. The dialysis removal of 6 drugs was evaluated in HD rats. Dialysis efficiency, plasma protein binding rate (PBR) and distribution volume (Vd) of drugs were also measured. Furthermore, we examined the correlation between the dialyzability of drug in HD rats and humans and constructed the prediction formula of the drug dialyzability in HD patients. The clearance of urea and creatinine and normalized dialysis dose in HD rats were 0.83 ± 0.07 mL/min, 0.70 ± 0.08 mL/min, and 0.13 ± 0.06, respectively. The drug dialyzability in HD rats was similar to reported clinical data except for doripenem. A higher correlation was observed between drug dialyzability in reported clinical data and HD rats which were adjusted for PBR (r² = 0.936; p < 0.001) compared to unadjusted (r² = 0.812; p = 0.009). Therefore, we constructed the prediction formula of the drug dialyzability in HD patients by utilizing the HD rat model and PBR. This study is useful for evaluating the dialyzability of high-risk drugs in a clinical setting and might provide appropriate preclinical dialyzability data for new drug.

Comparison of the pain-reducing effects of EMLA cream and of lidocaine tape during arteriovenous fistula puncture in patients undergoing hemodialysis: A multi-center, open-label, randomized crossover trial

Arteriovenous fistula puncture pain is a serious problem for patients undergoing dialysis and a good indication for topical anesthetics. No previous study has compared lidocaine/prilocaine cream (EMLA) with lidocaine tape for pain relief during arteriovenous fistula puncture in patients undergoing maintenance hemodialysis. To this end, we conducted a multicenter randomized crossover study including 66 patients (mean age, 65.8 years; males, 57.6%) undergoing maintenance hemodialysis thrice/week. Subjects were assigned to Sequence EL (EMLA administration followed by lidocaine, with 1-week wash-out) or Sequence LE (reverse administration, first lidocaine then EMLA). All subjects completed the study. At each puncture site, 1 g EMLA (25 mg lidocaine + 25 mg prilocaine) or one sheet of lidocaine tape (18 mg lidocaine) was applied 1 h or 30 min prior to arteriovenous fistula puncture, respectively. The primary endpoint was puncture pain relief, which was measured using a 100-mm visual analog scale. The secondary endpoints included quality of life, which was measured by SF-36, and safety. EMLA produced a 10.1-mm greater visual analog scale improvement than lidocaine tape (P = 0.00001). However, there was no statistically significant difference in the quality of life between the two groups, and no significant carryover/period effect was observed in any analysis. Further, no drug-related adverse events were observed. Taken together, these results suggest that EMLA cream is superior to lidocaine tape for the relief of arteriovenous fistula puncture pain in patients undergoing maintenance hemodialysis. Trial registration: University Hospital Medical Information Network Clinical Trials Registry (UMIN000027885).

Modified creatinine index and risk for long-term infection-related mortality in hemodialysis patients: ten-year outcomes of the Q-Cohort Study

Modified creatinine (Cr) index, calculated by age, sex, pre-dialysis serum Cr concentration, and Kt/V for urea, is an indicator of skeletal muscle mass in hemodialysis (HD) patients. It remains unknown whether the modified Cr index predicts infection-related mortality in this population. We investigated the association between the modified Cr index and infection-related mortality. A total of 3046 patients registered in the Q-Cohort Study, a multicenter, observational study of HD patients, were analyzed. Associations between sex-specific quartiles (Q1–Q4) of the modified Cr index and the risk for infection-related mortality were analyzed by Cox proportional hazard model. During a median follow-up of 8.8 years, 387 patients died of infection. The estimated risk for infection-related mortality was significantly higher in the lower quartiles (Q1, Q2, and Q3) than in the highest quartile (Q4) as the reference group (hazard ratios and 95% confidence intervals [CI]: Q1, 2.89 [1.70–5.06], Q2, 2.76 [1.72–4.62], and Q3, 1.79 [1.12–2.99]). The hazard ratio (95% CI) for a 1 mg/kg/day decrease in the modified Cr index was 1.18 (1.09–1.27, P < 0.01) for infection-related mortality. In conclusion, a lower modified Cr index is associated with an increased risk for long-term infection-related mortality in the HD population.

Survival comparison between superficialization of the brachial artery and tunneled central venous catheter placement in hemodialysis patients with heart failure: A retrospective study

It remains unclear which vascular access provides better survival in hemodialysis patients with heart failure, superficialization of the brachial artery (SBA), or tunneled central venous catheter (TCVC). We retrospectively followed up 60 hemodialysis patients with heart failure who underwent SBA (n = 36) or TCVC placement (n = 24). During the median 2.2-year follow-up period, 36 patients died. The median survival time was significantly longer for the SBA group than for the TCVC group (5.7 vs 1.7 years; P < .05, log-rank test). A multivariate-adjusted Cox regression analysis showed that SBA was associated with a reduced risk of all-cause death (hazard ratio [HR] 0.30; 95% confidence interval [CI] 0.14-0.65). In the cohort of propensity score-matched 15 pairs, patients with SBA experienced fewer all-cause deaths (HR 0.29; 95% CI 0.10-0.77). Our study suggests that SBA is an alternative option in hemodialysis patients with heart failure.

Postdialysis Hypokalemia and All-Cause Mortality in Patients Undergoing Maintenance Hemodialysis

BACKGROUND AND OBJECTIVES

Almost half of patients on dialysis demonstrate a postdialysis serum potassium ≤3.5 mEq/L. We aimed to examine the relationship between postdialysis potassium levels and all-cause mortality.

DESIGN, SETTING, PATIENTS, & MEASUREMENTS

We conducted a cohort study of 3967 participants on maintenance hemodialysis from the Dialysis Outcomes and Practice Patterns Study in Japan (2009-2012 and 2012-2015). Postdialysis serum potassium was measured repeatedly at 4-month intervals and used as a time-varying variable. We estimated the hazard ratio of all-cause mortality rate using Cox hazard regression models, with and without adjusting for time-varying predialysis serum potassium. Models were adjusted for baseline characteristics and time-varying laboratory parameters. We also analyzed associations of combinations of pre- and postdialysis potassium with mortality.

RESULTS

The age of participants at baseline was 65±12 years (mean±SD), 2552 (64%) were men, and 96% were treated with a dialysate potassium level of 2.0 to <2.5 mEq/L. The median follow-up period was 2.6 (interquartile range, 1.3-2.8) years. During the follow-up period, 562 (14%) of 3967 participants died, and the overall mortality rate was 6.7 per 100 person-years. Compared with postdialysis potassium of 3.0 to <3.5 mEq/L, the hazard ratios of postdialysis hypokalemia (<3.0 mEq/L) were 1.84 (95% confidence interval, 1.44 to 2.34) in the unadjusted model, 1.44 (95% confidence interval, 1.14 to 1.82) in the model without adjusting for predialysis serum potassium, and 1.10 (95% confidence interval, 0.84 to 1.44) in the model adjusted for predialysis serum potassium. The combination of pre- and postdialysis hypokalemia was associated with the highest mortality risk (hazard ratio, 1.72; 95% confidence interval, 1.35 to 2.19, reference; pre- and postdialysis nonhypokalemia).

CONCLUSIONS

Postdialysis hypokalemia was associated with mortality, but this association was not independent of predialysis potassium.

Current status of vascular access in Japan-from Dialysis Access Symposium 2017

At the second Dialysis Access Symposium held in Nagoya, Japan, a proposal was made to investigate the differences in vascular access methods used in different countries. In this article, we describe the management of vascular access in Japan. The Japanese population is rapidly aging, and the proportion of elderly patients on dialysis is also increasing. There were 325,000 dialysis patients in Japan at the end of 2015, of whom 65.1% were aged 65 years or above. The number of patients with diabetic nephropathy or nephrosclerosis as the underlying condition is also increasing, whereas the number with chronic glomerulonephritis is steadily decreasing. The Japanese health insurance system enables patients to undergo medical treatment at almost no out-of-pocket cost. Percutaneous transluminal angioplasty suffers from a severe device lag compared with other countries, but although there are limitations on permitted devices, the use of those that have been authorized is covered by medical insurance. One important point that is unique to Japan is that vascular access is performed and managed by doctors involved in dialysis across a wide range of disciplines, including nephrologists, surgeons, and urologists. This may be one factor contributing to the good survival prognosis of Japanese dialysis patients.

The association of the difference in hemoglobin levels before and after hemodialysis with the risk of 1-year mortality in patients undergoing hemodialysis. Results from a nationwide cohort study of the Japanese Renal Data Registry

Background

Few clinical studies have directly examined the associations of hemoglobin (Hb) levels after hemodialysis (HD) and of the difference in Hb levels before and after HD (ΔHb) with patient outcomes. The present study aimed to determine ΔHb and post-HD Hb levels with nationwide data and to examine their associations with all-cause mortality in patients undergoing HD.

Methods

This study is based on data from 2008 and 2009 recorded in the Japanese Renal Data Registry. Study endpoints were all-cause mortality within 1-year. The ΔHb and post-HD Hb level as categorical variables using Cox regression for 1-year mortality, adjusting for potential confounders.

Results

The median ΔHb was 1.0 g/dl, and the post-HD Hb level was 11.3 g/d. The median pre-HD Hb level was 10.4 g/dl. The risk of mortality was lower with a ΔHb of 0 to 1.0 g/dl (adjusted hazard ratio [aHR], 0.90; 95% confidence interval [CI], 0.70–1.01) or > 1.0 g/dl (aHR, 0.73; 95% CI, 0.64–0.84) than with a ΔHb < 0 g/dl. The risk for mortality was also lower with a post-HD Hb of 10 to 11 g/dl (aHR, 0.82; 95% CI, 0.73–0.92), 11 to 12 g/dl (aHR, 0.77; 95% CI, 0.68–0.87), or > 12 g/dl (aHR, 0.77; 95% CI, 0.68–0.87) than with a post-HD Hb < 10 g/dl.

Conclusions

Both a low ΔHb and a low post-HD Hb level were associated with a higher risk of 1-year mortality.

Changes to indications for tunneled cuffed catheter use in hemodialysis patients: A single-center experience

INTRODUCTION

As the number of elderly end-stage renal disease patients lacking suitable vessels for arteriovenous fistula (AVF) is increasing, indications for tunnel cuffed catheters (TCCs) may be expanding. This study aimed to clarify changes over time in the number of patients with TCC and indications for TCCs.

METHODS

This single-center retrospective study analyzed 143 catheters for 95 patients who inserted TCCs between July 2005 and July 2017. Patients were divided into two groups (early- and late-phase groups) based on the median observational period. Demographic data and clinical information were then compared.

FINDINGS

Fifty TCCs were inserted in the early phase group, and 93 TCCs were inserted in the late-phase group. The late-phase group was older (77 vs. 70 years; P = 0.003) and showed a higher frequency of hypertensive nephropathy (29% vs. 14%; P < 0.05) and a lower frequency of a history of cardiovascular disease (52.7% vs. 70.0%; P = 0.045). In the late-phase group, indications for bridge vascular access (0% vs. 11.8%; P < 0.05) or severe cardiac dysfunction (8.0% vs. 20.5%; P < 0.05) were increased. In addition, the late-phase group showed increases in percentage of patients with the catheter inserted in the femoral vein (10.0% vs. 23.7%; P = 0.047), nephrologists performing catheter insertion (56.0% vs. 87.1%; P < 0.001), and the patients who underwent superficialization of the brachial artery (28.0% vs. 46.2%; P = 0.034). Significant differences in catheter survival, incidence of complications, reasons for catheter removal, or incidence of catheter-related infection were not observed between groups.

DISCUSSION

Patients with indications for TCC may be increasing due to an increase in elderly end-stage renal disease patients whose activities of daily living have decreased. In addition, indications for bridge vascular access were widely accepted in the late-phase group.

Current approaches to middle molecule removal: room for innovation

Aggressive removal of middle molecules or larger low-molecular-weight proteins (LMWPs) has been a growing concern following studies on their harmful effects on the mortality and morbidity of chronic dialysis patients. To remove larger LMWPs and some protein-bound uremic toxins (PBUTs), high- and medium-cutoff (HCOs and MCOs, respectively) membranes, convective therapy and protein adsorptive membranes are available. When we use HCO or MCO membranes for convective therapy, we have to take care to avoid massive albumin leakage during a dialysis session. Convection volume is an important element to increase middle molecule removal; however, a larger convection volume has a risk of larger leakage of albumin. Predilution hemodiafiltration is a useful measurement to increase larger LMWPs without massive albumin leakage. β2-microglobulin (B2M), α1-microglobulin (A1M) and albumin leakage during a dialysis session are useful parameters for assessing middle-molecule removal. Reduction ratios of B2M >80% and of A1M >35% are favorable to improve severe dialysis-related symptoms. The efficacy of middle molecule removal should be evaluated in comparison with clinical outcomes, mortality, morbidity and the improvement of dialysis-related symptoms. Recently some dialysis-related symptoms such as sleep disturbance, skin itchiness and dialysis hypotension have been recognized as good surrogate makers for mortality. Further studies to evaluate the relationship between middle molecule or PBUTs removal and the improvement of patient symptoms should be performed in well-designed randomized controlled trials.

Risk factors for severe hypocalcemia after parathyroidectomy in dialysis patients with secondary hyperparathyroidism

Severe hypocalcemia (SH) is a common and serious complication in dialysis patients with secondary hyperparathyroidism (SHPT) after parathyroidectomy (PTX). The aim is to explore the risk predictors of SH in post-PTX dialysis ESRD patients with SHPT. 129 consecutive dialysis patients with SHPT underwent PTX were retrospectively reviewed. A total of 22 clinical parameters were included in the study. SH was defined as the minimum values of serum calcium lower than 1.875 mmol/L (7.5 mg/dL) after surgery. Univariate analysis showed that pruritus, lumbar X-ray changes of renal osteodystrophy, pre- and post-operative intact parathyroid hormone (iPTH), Calcium, alkaline phosphatase, and gland mass were significantly different between SH and non-SH groups. In the multivariate logistic regression model, the pre-operative serum iPTH, calcium, and pruritus were independent risk predictors of SH. AUCs for pre-operative serum iPTH, calcium and pruritus were 0.810, 0.714 and 0.591, respectively. Patients with higher level of pre-operative serum iPTH, lower level of serum calcium and with no/mild symptoms of pruritus are at greater risk of developing SH after PTX.

Systemic Inflammatory Response Syndrome Is Not an Indicator of Bacteremia in Hemodialysis Patients With Native Accesses: A Multicenter Study

Bloodstream infection (BSI) in hemodialysis (HD) patients is often difficult to diagnose. Systemic inflammatory response syndrome (SIRS) is a sensitive predictor of BSI in the general population. We aimed to assess the usefulness of SIRS in predicting BSI in HD patients. We designed a multicenter retrospective observational study of adult (age > 18 years) HD patients who underwent two sets of blood cultures for suspected BSI at first hospital visit from August 2011 to July 2012. Clinical, biological, and microbial data were evaluated to evaluate SIRS as a predictor of BSI upon initial presentation to the hospital. Data were obtained from 279 HD patients. Vascular access other than arteriovenous fistula and subcutaneously fixed superficial artery, and those administered antimicrobial drugs before visit were excluded; thus, a total of 202 patients were finally enrolled. Mean patient age was 71 years, 67.3% were male, 49.3% had diabetes, 28.2% had indwelling hardware, and 18.3% patients had BSI. Endocarditis and vertebral osteomyelitis were common infection sites, and Staphylococcus aureus was the most common pathogen. Of those with SIRS, 25.3% had BSI and 74.7% did not (odds ratio for SIRS, 2.10; 95% confidence interval, 0.90-4.91; p = 0.11). Thus, SIRS had a low sensitivity for predicting BSI in HD patients (sensitivity, 71.9%; specificity, 45.2%; positive likelihood ratio, 1.31; negative likelihood ratio, 0.62). Systemic inflammatory response syndrome has low sensitivity in identifying BSI in HD patients. A low threshold for drawing blood cultures and initiating antibiotic treatment should be considered for HD patients.

Body Mass Index Change and Hospitalization Risk in Elderly Hemodialysis Patients: Results from Japanese Dialysis Outcomes and Practice Patterns Study

BACKGROUND

Short-term weight gains and losses are associated with a lower and higher mortality risk, respectively, in patients undergoing hemodialysis (HD). However, little is known about their association with the risk of subsequent hospitalization.

METHODS

In a prospective cohort of 1,804 HD patients aged ≥65 years enrolled in the Japanese Dialysis Outcomes and Practice Patterns Study phases 3 (2005-2008) and 4 (2009-2011), we examined the associations between changes in body mass index (BMI) over a 4-month baseline period (<-3%, -3 to <-1%, -1 to <1% [reference], 1 to <3%, and ≥3%) and subsequent risk of all-cause, cardiovascular, and noncardiovascular hospitalization using Cox models with adjustment for potential confounders.

RESULTS

During a median follow-up of 1.2 years, we noted 1,028 incident hospitalizations for any cause, including 275 and 753 hospitalizations for cardiovascular and noncardiovascular causes, respectively. An L-shaped association was observed between BMI change and all-cause hospitalization. The multivariable-adjusted hazard ratios (HRs; 95% CI) of all-cause hospitalization associated with BMI changes of <-3%, -3 to <-1%, 1 to <3%, and ≥3% (vs. -1 to <1%) were 1.29 (1.01-1.65), 1.22 (0.98-1.51), 1.04 (0.83-1.29), and 1.10 (0.83-1.45), respectively. Qualitatively similar associations were present for cardiovascular-related hospitalization (corresponding HRs [95% CI]: 1.58 [1.06-2.37], 1.09 [0.75-1.58], 0.99 [0.72-1.36], and 0.91 [0.51-1.64], respectively) but not for noncardiovascular-related hospitalization (corresponding HRs [95% CI]: 1.19 [0.90-1.57], 1.26 [0.99-1.59], 1.06 [0.84-1.35], and 1.18 [0.86-1.63], respectively).

CONCLUSIONS

Decreases in BMI over a relatively short-term period were independently associated with higher risk of subsequent hospitalization, particularly cardiovascular-related hospitalization, among elderly HD patients.

Clinical Outcomes after Isolated Infrapopliteal Revascularization in Hemodialysis Patients with Critical Limb Ischemia: Endovascular Therapy versus Bypass Surgery

AIM

To investigate the long-term clinical outcome of endovascular therapy (EVT) or bypass surgery in patients on hemodialysis (HD) with critical limb ischemia due to isolated infrapopliteal disease.

METHODS

We enrolled 254 consecutive HD patients successfully undergoing infrapopliteal revascularization by EVT (126 patients) and bypass surgery (128 patients). They were followed up for five years. Amputation-free survival (AFS) and incidence of any re-intervention were evaluated. A propensity score from all baseline variables was incorporated into Cox analysis.

RESULTS

In the EVT group, age was higher (p=0.039), diabetes and coronary artery disease were more frequent (p=0.004 and p=0.0052, respectively), and tissue loss was more rarely observed (p＜ 0.0001) than in the bypass group. During the follow-up period, 21 major amputations and 64 deaths occurred. The propensity score-adjusted AFS rate at 5 years was comparable between groups (61.0% in EVT group vs. 55.1% in the bypass group, adjusted hazard ratio [HR] 0.87, 95% confidence interval [CI] 0.52-1.42, p=0.58). The adjusted survival rates were also similar between groups for amputation and all-cause mortality. However, freedom from any re-intervention was markedly lower in the EVT than in the bypass group (48.6% vs. 84.6%, adjusted-HR, 3.56, 95% CI 1.95-6.75, p＜ 0.0001).

CONCLUSIONS

The rate of AFS was broadly comparable between the two strategies, although compared with bypass surgery, EVT had much higher rates for re-intervention.

Comparison of accuracy between pre-hemodialysis and post-hemodialysis levels of nutritional factors for prediction of mortality in hemodialysis patients

BACKGROUND

The nutritional status of hemodialysis (HD) patients is usually assessed using pre-HD laboratory data. However, it remains unclear whether the most diluted laboratory value is appropriate for assessment. We compared the pre-HD and post-HD laboratory data for their accuracy in predicting mortality.

METHODS

Maintenance HD patients (n = 96 700; men, 61.5%) were enrolled. The outcome events were one-year and five-year mortalities. Their laboratory data included body mass index (BMI), and serum albumin, creatinine, and blood urea nitrogen (BUN) levels. Bootstrap resampling was used to compare the accuracy in predicting the mortalities between pre-HD and post-HD levels using area under receiver operating characteristic curves (AUCs) adjusted for baseline characteristics.

RESULTS

The mean age ± standard deviation was 65.7 ± 12.2 years, and the vintage was 8.3 ± 6.7 years. The numbers of patients who died were 6442 (6.7%) in one year and 30 965 (32.0%) in five years. The adjusted AUCs for predicting the one-year and five-year mortalities showed that the pre-HD albumin and creatinine levels and the pre-HD BMI and BUN levels were more accurate than the post-HD levels (each p < 0.0001). The pre-HD albumin and creatinine levels showed the highest adjusted AUC for predicting one-year mortality [0.613 (95% CI 0.598, 0.629)] and five-year mortality [0.591 (95% CI 0.586, 0.595)], respectively.

CONCLUSIONS

Pre-HD albumin and creatinine levels are more accurate than post-HD levels and other nutritional indices in predicting one-year and five-year mortalities in HD patients.

Effect of dialyzer membrane materials on survival in chronic hemodialysis patients: Results from the annual survey of the Japanese Nationwide Dialysis Registry

BACKGROUND

Little information is available regarding which type of dialyzer membrane results in good prognosis in patients on chronic hemodialysis. Therefore, we conducted a cohort study from a nationwide registry of hemodialysis patients in Japan to establish the association between different dialyzer membranes and mortality rates.

METHODS

We followed 142,412 patients on maintenance hemodialysis (female, 39.1%; mean age, 64.8 ± 12.3 years; median dialysis duration, 7 [4-12] years) for a year from 2008 to 2009. We included patients treated with seven types of high-flux dialyzer membranes at baseline, including cellulose triacetate (CTA), ethylene vinyl alcohol (EVAL), polyacrylonitrile (PAN), polyester polymer alloy (PEPA), polyethersulfone (PES), polymethylmethacrylate (PMMA), and polysulfone (PS). Cox regression was used to estimate the association between baseline dialyzers and all-cause mortality as hazard ratios (HRs) and 95% confidence intervals for 1-year mortality adjusting for potential confounders, and propensity score matching analysis was performed.

RESULTS

The distribution of patients treated with each membrane was as follows: PS (56.0%), CTA (17.3%), PES (12.0%), PEPA (7.5%), PMMA (4.9%), PAN (1.2%), and EVAL (1.1%). When data were adjusted using basic factors, with PS as a reference group, the mortality rate was significantly higher in all groups except for the PES group. When data were further adjusted for dialysis-related factors, HRs were significantly higher for the CTA, EVAL, and PEPA groups. When the data were further adjusted for nutrition-and inflammation-related factors, HRs were significantly lower for the PMMA and PES groups compared with the PS group. After propensity score matching, HRs were significantly lower for the PMMA group than for the PS group.

CONCLUSION

The results suggest that the use of different membrane types may affect mortality in hemodialysis patients. However, further long-term prospective studies are needed to clarify these findings, including whether the use of the PMMA membrane can improve prognosis.

High-Performance Membrane Dialyzers and Mortality in Hemodialysis Patients: A 2-Year Cohort Study from the Annual Survey of the Japanese Renal Data Registry

BACKGROUND

Little information is available regarding the type of dialyzer which results in good prognosis. This study is aimed at investigating the association between 7 types of dialyzers and 2-year mortality.

METHODS

We conducted a cohort study using data from a nationwide registry of the Japanese Society for Dialysis Therapy. Subjects were 136,676 patients on maintenance hemodialysis (HD) between 2009 and 2011 who underwent maintenance HD for at least 2 years and were treated with one of the following 7 types of high-performance membrane dialyzers: cellulose triacetate (CTA), ethylene vinyl alcohol (EVAL), polyacrylonitrile (PAN), polyester polymer alloy (PEPA), polyethersulfone (PES), polymethylmethacrylate (PMMA), and polysulfone (PS). Cox regression was used to estimate the association between baseline dialyzers and all-cause 2-year mortality, adjusting for potential confounders.

RESULTS

Data were adjusted using basic factors, with PS as a reference group, and the hazard ratio (HR) was significantly higher in CTA, PMMA, PAN, and EVAL groups. Further data adjustment for Kt/V yielded the same results as were obtained from data adjusted for basic factors. After further adjustment for nutrition- and inflammation-related factors, HR was significantly lowered for the PES and PMMA groups compared with the PS group (HR 0.88; 95% CI 0.82-0.94 and HR 0.84 95% CI 0.76-0.93, respectively). After propensity score matching, HR for the PES and PMMA groups was significantly lowered compared with the PS group.

CONCLUSIONS

The use of different membrane types may affect mortality. Further long-term prospective studies are needed to clarify whether the PES and PMMA membranes can improve prognosis.

Introduction of arteriovenous grafts with graft insertion anastomosis for hemodialysis access

OBJECTIVE

An arteriovenous bridging graft is a viable option for patients with compromised arteries or veins because of advanced age or diabetes. Arteriovenous graft with graft insertion anastomosis (AVGI) is the novel technique for graft-vein anastomosis where the prosthesis is inserted into the vein, and the anastomosis is performed on the surface of the prosthesis. This study assessed the short-term and long-term results of AVGI to clarify the efficacy of this technique.

METHODS

Between 2010 and 2015, AVGI was performed in graft-vein anastomosis of prosthetic forearm loop access. Characteristics and level of complications were assessed. To evaluate the long-term results, functional graft patency and frequency of percutaneous transluminal angioplasty were examined.

RESULTS

The study comprised 58 patients. There were no deaths related to the surgery. The time of hemostasis after AVGI was recorded at 0 seconds because no bleeding from the suture holes was seen. At 1, 2, and 3 years, primary patency were 45.1% ± 7.5%, 23.1% ± 7.5%, and 23.1% ± 7.5%, respectively, and assisted primary patency rates were 59.4% ± 7.2%, 50.8% ± 7.6%, and 50.8% ± 7.6%, respectively. Secondary patency rates at 4 and 5 years were 100% ± 0% and 94.1% ± 5.7%, respectively. The frequency of percutaneous balloon angioplasty to maintain the patency was 1.61 ± 0.53 times per year. Graft infection occurred in four patients (6.9%).

CONCLUSIONS

AVGI is an advantageous technique for graft vein anastomosis in an arteriovenous bridging graft in both the short-term and long-term.

To assess the effects of parathyroidectomy (TPTX versus TPTX+AT) for Secondary Hyperparathyroidism in chronic renal failure: A Systematic Review and Meta-Analysis

BACKGROUND

Secondary Hyperparathyroidism (SHPT) requiring parathyroidectomy (PTX) occurs more commonly in patients with progressive chronic kidney disease and in those on long-term lithium therapy. Successful PTX often results in a dramatic drop of parathyroid hormone level, relieves the patient from clinical symptoms, and reduces mortality. However, there is an ongoing debate on the optimal surgical treatment of SHPT. Currently, no clinical guidelines or trials have definitely answered the question of whether Total Parathyroidectomy (TPTX) is superior or equal to Total Parathyroidectomy with Autotransplantation (TPTX + AT).

OBJECTIVE

The aims of the study were to compare the efficacy of two different surgical procedures and to develop evidence-based practice guidelines for the treatment of SHPT.

METHODS

Citations were identified in the Medline, Cochrane, EMBASE, and Chinese Biomedical Literature databases through November 2016. The Newcastle-Ottawa Scale (NOS) score was used to assess the methodological quality of the studies included. All data were analyzed using Review Manager 5.3.

RESULTS

A total of nine cohort studies and one Randomized Controlled Trials (RCT), comprising 1283 patients, were identified. The NOS score of all the studies included was 5 or above. Compared with TPTX + AT, patients in the TPTX group had lower rates of "recurrence" (OR = 0.20; 95%CI, 0.11-0.38; P < 0.01), "recurrence or persistence" (OR = 0.18; 95%CI, 0.10-0.33; P < 0.01), "reoperation due to recurrence or persistence" (OR = 0.17; 95%CI, 0.06-0.54; P = 0.002), and shorter "operative time" (WMD = -17.30; 95%CI, -30.53 to -4.06; P < 0.05), except for a higher risk of "hypoparathyroidism" (OR = 2.97; 95%CI, 1.09-8.08; P = 0.01). However, none of the patients had developed permanent hypocalcemia or adynamic bone disease. No significant difference was found for "symptomatic improvement", "complications", "drug requirements", and "hospital stay" (P > 0.05).

CONCLUSION

The findings indicate that TPTX is superior to TPTX + AT, while referring to the rate of recurrent SHPT. However, this conclusion needs to be tested in large-scale confirmatory trials. TPTX seems to be a feasible alternative therapeutic option for the surgical treatment of refractory SHPT.

Early use of autogenous arteriovenous fistula in patients with urgent hemodialysis

PURPOSE

This study was designed to evaluate the long-term patency rate and complications associated with early use of the autogenous forearm arteriovenous fistula (AFAVF) in patients needing urgent hemodialysis.

METHODS

The clinical data of all patients undergoing AFAVFs for hemodialysis access between June 1996 and June 2016 were retrospectively evaluated. The primary and secondary patencies were estimated using the life table method.

RESULTS

A total of 104 AFAVFs were created for 102 patients. All patients had entered hemodialysis when fistulas were constructed. The mean time to the first cannulation of the AFAVF was 17.33 ± 4.60 (5-27 days). Four AFAVFs (3.8%) became occluded within 30 days of creation of the access, and five AFAVFs (4.8%) had hematomas after cannulation. There were no cases of infection of the wound or steal syndrome or prolonged arm edema. The primary patency rate was 77.81% at 1 year, 73.05% at 2 years, 64.64% at 3 years, 60.75% at 5 years and 47.48% at 10 years. The secondary patency rate was 96.78% at 1 year, 95.18% at 5 years and 85.81% at 10 years.

CONCLUSIONS

In this study, the patency rates following the early use of the AFAVFs were not inferior to the previously reported patency rates in the literature. For patients entering hemodialysis with an inserted central catheter, the early use of the AFAVFs decreases the complications associated with catheters.

An Overview of Regular Dialysis Treatment in Japan (As of 31 December 2013)

A nationwide survey of 4325 dialysis facilities was conducted at the end of 2013, among which 4268 (98.7%) responded. The number of new dialysis patients was 38,095 in 2013. Since 2008, the number of new dialysis patients has remained almost the same without any marked increase or decrease. The number of dialysis patients who died in 2013 was 30,751. The dialysis patient population has been growing every year in Japan; it was 314,438 at the end of 2013. The number of dialysis patients per million at the end of 2013 was 2470. The crude death rate of dialysis patients in 2013 was 9.8%. The mean age of new dialysis patients was 68.7 years and the mean age of the entire dialysis patient population was 67.2 years. The most common primary cause of renal failure among new dialysis patients was diabetic nephropathy (43.8%). The actual number of new dialysis patients with diabetic nephropathy has almost been unchanged for the last few years. Diabetic nephropathy was also the most common primary disease among the entire dialysis patient population (37.6%), followed by chronic glomerulonephritis (32.4%). The percentage of dialysis patients with diabetic nephropathy has been increasing continuously, whereas the percentage of dialysis patients with chronic glomerulonephritis has been decreasing. The number of patients who underwent hemodiafiltration (HDF) at the end of 2013 was 31,371, a marked increase from that in 2012. This number is more than twice that at the end of 2011 and approximately 1.5 times the number at the end of 2012. In particular, the number of patients who underwent online HDF increased approximately fivefold over the last 2 years. Among 151,426 dialysis patients with primary causes of renal failure other than diabetic nephropathy, 10.8% had a history of diabetes. Among those with a history of diabetes, 26.8% used glycoalbumin as an indicator of blood glucose level; and 33.0 and 27.6% were administered insulin and dipeptidyl peptidase (DPP)-4 inhibitor, respectively, as a medication of diabetes. The facility survey showed that 9392 patients underwent peritoneal dialysis (PD). The patient survey revealed that 1920 of these PD patients also underwent another dialysis method using extracorporeal circulation, such as hemodialysis (HD) or HDF. The number of patients who underwent HD at home at the end of 2013 was 461, a marked increase from that at the end of 2012 (393).

Mortality trends among Japanese dialysis patients, 1988-2013: a joinpoint regression analysis

BACKGROUND

Evaluation of mortality trends in dialysis patients is important for improving their prognoses. The present study aimed to examine temporal trends in deaths (all-cause, cardiovascular, noncardiovascular and the five leading causes) among Japanese dialysis patients.

METHODS

Mortality data were extracted from the Japanese Society of Dialysis Therapy registry. Age-standardized mortality rates were calculated by direct standardization against the 2013 dialysis population. The average annual percentage of change (APC) and the corresponding 95% confidence interval (CI) were computed for trends using joinpoint regression analysis.

RESULTS

A total of 469 324 deaths occurred, of which 25.9% were from cardiac failure, 17.5% from infectious disease, 10.2% from cerebrovascular disorders, 8.6% from malignant tumors and 5.6% from cardiac infarction. The joinpoint trend for all-cause mortality decreased significantly, by -3.7% (95% CI -4.2 to -3.2) per year from 1988 through 2000, then decreased more gradually, by -1.4% (95% CI -1.7 to -1.2) per year during 2000-13. The improved mortality rates were mainly due to decreased deaths from cardiovascular disease, with mortality rates due to noncardiovascular disease outnumbering those of cardiovascular disease in the last decade. Among the top five causes of death, cardiac failure has shown a marked decrease in mortality rate. However, the rates due to infectious disease have remained stable during the study period [APC 0.1 (95% CI -0.2-0.3)].

CONCLUSIONS

Significant progress has been made, particularly with regard to the decrease in age-standardized mortality rates. The risk of cardiovascular death has decreased, while the risk of death from infection has remained unchanged for 25 years.

Early Mortality Was Highly and Strongly Associated with Functional Status in Incident Japanese Hemodialysis Patients: A Cohort Study of the Large National Dialysis Registry

Background

Although dialysis is typically started in an effort to prolong survival, mortality is reportedly high in the first few months. However, it remains unclear whether this is true in Japanese patients who tend to have a better prognosis than other ethnicities, and if health conditions such as functional status (FS) at initiation of dialysis influence prognosis.

Methods

We investigated the epidemiology of early death and its association with FS using Japanese national registry data in 2007, which included 35,415 patients on incident dialysis and 7,664 with FS data. The main outcome was early death, defined as death within 3 months after initiation of hemodialysis (HD). The main predictor was FS at initiation of HD. Levels of functional disability were categorized as follows: severe (bedridden), moderate (overt difficulties in exerting basic activities of daily living), or mild/none (none or some functional disabilities).

Results

Early death remained relatively common, especially among elderly patients (overall: 7.1%; those aged ≥80 years: 15.8%). Severely and even only a moderately impaired FS were significantly associated with early death after starting dialysis (adjusted risk ratios: 3.93 and 2.38, respectively). The incidence of early death in those with impaired FS increased with age (36.5% in those with severely impaired FS and aged ≥80 years).

Conclusions

Early death after starting dialysis was relatively common, especially among the elderly, even in Japanese patients. Further, early death was significantly associated with impaired FS at initiation of HD.

Serum Creatinine Modifies Associations between Body Mass Index and Mortality and Morbidity in Prevalent Hemodialysis Patients

Background

High body mass index (BMI) is paradoxically associated with better outcomes in hemodialysis (HD) patients. This study aimed to examine whether serum creatinine (Cr), a marker of muscle mass, could modify the association between BMI, and mortality and morbidity in prevalent HD patients.

Methods

A retrospective study was conducted using a nationwide database from the registry of the Japanese Society for Dialysis Therapy. A total of 119,099 patients were selected (age: 65±12 years; median time on HD: 5.6 years; male: 62%), and we examined the association of basal BMI with mortality and morbidity after a 1-year period. Patients were stratified either by BMI into 4 groups or by serum Cr levels into 3 tertiles. Odds ratio (OR) [95% confidence interval] was calculated by multivariate logistic regression analysis.

Results

Higher BMI did not predict a higher 1-year total mortality. However, when we stratified the patients by serum Cr levels, the risk of cardiac death became significantly higher in obese patients with the lowest Cr levels, in both males (OR 2.82 [1.51–5.27], p<0.01) and females (OR 2.00 [1.03–3.90], p<0.05). The risk of new cerebral infarction was also higher in obese male patients within the lowest Cr tertile. In contrast, there was a significantly lower risk of cardiac, cerebrovascular, and infection-related death in non-obese patients with higher levels of Cr. Higher serum Cr was also related to a lower risk of cardiovascular events and hip fracture in non-obese HD patients.

Conclusions

The obesity paradox was found to be present in HD patients only when obesity was defined by BMI. Decreased serum Cr levels were found to be positively associated with clinical poor outcomes in all BMI groups. Thus, irrespective of BMI, the evaluation of serum Cr levels is important to predict mortality and morbidity in patients receiving regular HD.

Low parathyroid hormone status induced by high dialysate calcium is an independent risk factor for cardiovascular death in hemodialysis patients

Here we studied a possible association between low parathyroid hormone (PTH) status and mortality in incident patients undergoing hemodialysis . A total of 1983 patients were included at baseline and prospectively followed for 24 months. Patients were classified according to their Kidney Disease: Improving Global Outcomes PTH status at baseline and at 12 months, and mortality evaluated at 12 to 24 months using adjusted Cox analysis. Factors potentially involved in PTH status variability between baseline and 12 months were analyzed. A decrease in serum PTH from normal or high to low values between baseline and 12 months was associated with significantly increased cardiovascular mortality at 12 to 24 months (hazard ratio, 2.03; 95% confidence interval, 1.22-3.36). For patients with high or normal baseline PTH levels, the main independent factor at 6 months for a decrease to low PTH levels at 12 months was high dialysate calcium (1.75 mmol/L), whereas prescription of non-calcium-based phosphate binders was associated with a lower risk of PTH decrease. In the high cardiovascular (CV) mortality risk subgroup of patients who acquired a low PTH status at 12 months, the main independent factor at 12 months associated with significant 12- to 24-month CV mortality was high dialysate calcium (odds ratio, 5.44; 95% CI, 2.52-11.75). Thus, patients with a serum PTH decrease to low values after 1 year of hemodialysis treatment are at high risk of short-term CV death. High dialysate calcium was an important contributor to PTH oversuppression, and continued use was associated with increased CV mortality.

Dialyzer-related Thrombocytopenia due to a Polysulfone Membrane

A 72-year-old Japanese woman was admitted to our hospital with rapidly progressive glomerulonephritis associated with anti-glomerular basement membrane antibody. Hemodialysis (HD) therapy was initiated on the day of admission using a biocompatible polysulfone (PS) membrane. Her platelet count (PLT; ×10(4)/μL) decreased gradually from 58.7 (day 1) to 5.8 (day 25). Considering the possibility of dialyzer-related thrombocytopenia (DRT), we measured her PLT count before and after the HD session on day 72, which revealed a dramatic decrease of 7.5 to 4.3. This finding suggested that the PS dialyzer caused PLT depletion. After discontinuation of the PS dialyzer, DRT was resolved.