Effect of End-Stage Renal Disease Prospective Payment System on Utilization of Peritoneal Dialysis in Patients with Kidney Allograft Failure.

INTRODUCTION: The Center for Medicare and Medicaid Services (CMS) introduced an End Stage Renal Disease (ESRD) Prospective Payment System (PPS) in 2011 to increase the utilization of home dialysis modalities, including peritoneal dialysis (PD). Several studies have shown a significant increase in PD utilization after PPS implementation. However, its impact on patients with kidney allograft failure remains unknown. METHODS: We conducted an interrupted time series (ITS) analysis using data from the United States Renal Data System (USRDS) that include all adult kidney transplant recipients with allograft failure who started dialysis between 2005 and 2019. We compared the PD utilization in the pre-PPS period (2005-2010) to the fully implemented post-PPS period (2014 - 2019) for early (within 90 days) and late (91-365 days) PD experience. RESULTS: 27507 adult recipients with allograft failure started dialysis during the study period. There was no difference in early PD utilization between the pre-PPS and the post-PPS period in either immediate change (0.3% increase; 95%CI: -1.95%, 2.54%; p=0.79) or rate of change over time (0.28% increase per year; 95%CI: -0.16%, 0.72%; p=0.18). Subgroup analyses revealed a trend toward higher PD utilization post-PPS in for-profit and large-volume dialysis units. There was a significant increase in PD utilization in the post-PPS period in units with low PD experience in the pre-PPS period. Similar findings were seen for the late PD experience. CONCLUSION: PPS did not significantly increase the overall utilization of PD in patients initiating dialysis after allograft failure.

ASDIN white paper: Management of cephalic arch stenosis endorsed by the American Society of Diagnostic and Interventional Nephrology.

Brachiocephalic arteriovenous fistulas (AVF) makeup approximately one third of prevalent dialysis vascular accesses. The most common cause of malfunction with this access is cephalic arch stenosis (CAS). The accepted requirement for treatment of a venous stenosis lesion is ⩾50% stenosis associated with hemodynamically abnormalities. However, the correlation between percentage stenosis and a clinically significant decrease in access blood flow (Qa) is low. The critical parameter is the absolute minimal luminal diameter (MLD) of the lesion. This is the parameter that exerts the key restrictive effect on Qa and results in hemodynamic and functional implications for the access. CAS is the result of low wall shear stress (WSS) resulting from the effects of increased blood flow and the unique anatomical configuration of the CAS. Decrease in WSS has a linear relationship to increased blood flow velocity and neointimal hyperplasia exhibits an inverse relationship with WSS. The result is a stenotic lesion. The presence of downstream venous stenosis causes an inflow-outflow mismatch resulting in increased pressure within the access. Qa in this situation may be decreased, increased, or within a normal range. Over time, the increased intraluminal pressure can result in marked aneurysmal changes within the AVF, difficulties with cannulation and the dialysis treatment, and ultimately, increasing risk of access thrombosis. Complete characterization of the lesion both hemodynamically and anatomically should be the first step in developing a strategy for management. This requires both access flow measurement and angiographic imaging. Patients with CAS present a relatively broad spectrum as relates to both of these parameters. These data should be used to determine whether primary treatment of CAS should be directed toward the anatomical lesion (small MLD and low Qa) or the pathophysiology (large MLD and high Qa).

Impact of COVID-19 pandemic on hemodialysis access thrombosis.

BACKGROUND: Delay in care of suspected stenosis or thrombosis can increase the chance of losing a functioning hemodialysis access. Access to care and resources were restricted during the COVID-19 pandemic. To evaluate the impact of the pandemic on arteriovenous fistula (AVF) and arteriovenous graft (AVG) procedures we have assessed the number and success of thrombectomies done before and during the COVID-19 pandemic. METHODS: We examined all AVF and AVG angiograms with and without interventions, including thrombectomies, performed at a single center during April 2017-March 2021 (pre-COVID-19 era) and April 2020-March 2021 (COVID-19 era). RESULTS: The proportion of procedures that were thrombectomies was higher during the COVID-19 era compared to the pre-COVID-19 era (13.3% vs 8.7%, p = 0.009). The proportion of thrombectomy procedures was higher during COVID-19 for AVF (8.2% vs 3.0%, p < 0.001) but there was no difference for AVG (26.5% vs 27%, p = 0.99). There was a trend toward a higher likelihood of unsuccessful thrombectomy during COVID-19 (33.3% vs 20.4%, p = 0.08). CONCLUSIONS: More dialysis access thromboses and unsuccessful thrombectomies were noted during the COVID-19 pandemic. This difference could be due to a delay in patients getting procedures to maintain their dialysis accesses.

Arteriovenous Access Type and Risk of Mortality, Hospitalization, and Sepsis Among Elderly Hemodialysis Patients: A Target Trial Emulation Approach.

RATIONALE & OBJECTIVE: Evidence is mixed regarding the optimal choice of the first permanent vascular access for elderly patients receiving hemodialysis (HD). Lacking data from randomized controlled trials, we used a target trial emulation approach to compare arteriovenous fistula (AVF) versus arteriovenous graft (AVG) creation among elderly patients receiving HD. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: Elderly patients included in the US Renal Data System who initiated HD with a catheter and had an AVF or AVG created within 6 months of starting HD. EXPOSURE: Creation of an AVF versus an AVG as the incident arteriovenous access. OUTCOMES: All-cause mortality, all-cause and cause-specific hospitalization, and sepsis. ANALYTICAL APPROACH: Target trial emulation approach, high-dimensional propensity score and inverse probability of treatment weighting, and instrumental variable analysis using the proclivity of the operating physician to create a fistula as the instrumental variable. RESULTS: A total of 19,867 patients were included, with 80.1% receiving an AVF and 19.9% an AVG. In unweighted analysis, AVF creation was associated with significantly lower risks of mortality and hospitalization, especially within 6 months after vascular access creation. In inverse probability of treatment weighting analysis, AVF creation was associated with lower incidences of mortality and hospitalization within 6 months after creation (hazard ratios of 0.82 [95% CI, 0.75-0.91] and 0.82 [95% CI, 0.78-0.87] for mortality and all-cause hospitalization, respectively), but not between 6 months and 3 years after access creation. No association between AVF creation and mortality, sepsis, or all-cause, cardiovascular disease-related, or infection-related hospitalization was found in instrumental variable analyses. However, AVF creation was associated with a lower risk of access-related hospitalization not due to infection. LIMITATIONS: Potential for unmeasured confounding, analyses limited to elderly patients, and absence of data on actual access use during follow-up. CONCLUSIONS: Using observational data to emulate a target randomized controlled trial, the type of initial arteriovenous access created was not associated with the risks of mortality, sepsis, or all-cause, cardiovascular disease-related, or infection-related hospitalization among elderly patients who initiated HD with a catheter.

Catheter Dependence After Arteriovenous Fistula or Graft Placement Among Elderly Patients on Hemodialysis.

RATIONALE & OBJECTIVE: Creation of an arteriovenous fistula (AVF), compared with an arteriovenous graft (AVG), is associated with longer initial catheter dependence after starting hemodialysis (HD) but longer access survival and lower long-term catheter dependence. The extent of these potential long-term benefits in elderly patients is unknown. We assessed catheter dependence after AVF or AVG placement among elderly patients who initiated HD without a permanent access in place. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: Patients≥67 years of age identified in the US Renal Data System who had a first AVF (n=14,532) or AVG (n=3,391) placed within 1 year after HD initiation between May 2012 and May 2017. EXPOSURE: AVF versus AVG placement in the first year of HD. OUTCOME: Catheter dependence after AVF or AVG placement assessed using CROWNWeb data. ANALYTICAL APPROACH: Generalized estimating equations and negative binomial regression for catheter use over time and Cox proportional hazards models for mortality. RESULTS: Creation of an AVF versus AVG placement was associated with greater catheter dependence at 1 month (95.6% vs 92.5%) and 3 months (82.8% vs 41.2%), but lower catheter dependence at 12 months (14.2% vs 15.8%) and 36 months (8.2% vs 15.0%). Creation of an AVF, however, remained significantly associated with greater cumulative catheter-dependent days (80.1 vs 54.6 days per person-year) and a lower proportion of catheter-free survival time (78.1% vs 85.1%) after 3 years of follow-up. LIMITATIONS: Potential for unmeasured confounding and analyses limited to elderly patients. CONCLUSIONS: Creation of an AVF was associated with significantly greater cumulative catheter dependence than placement of an AVG in an elderly population initiating HD without a permanent access. As the long-term benefits in terms of catheter dependence of an AVF are not realized in many elderly patients, specific patient characteristics should be considered when making decisions regarding vascular access.

Mega Fistulae! A case series.

A mega fistula can be defined as generalized aneurysmal dilatation of arteriovenous fistula. Mega fistulae can lead to complications like high output cardiac failure, steal syndrome, skin ulceration and rupture. We describe a series of ten patients who were referred to our interventional nephrology practice for evaluation of mega fistula which had not been in use for a long time. Nine out of ten patients were post-transplant while one was pre dialysis. Five patients had Radiocephalic while four had Brachiocephalic and one had Brachial artery to Median Cubital vein fistula. All except one patient had severe outflow stenosis. The most common site of stenosis in Radiocepahlic and Brachiocepahlic fistula was cephalic vein at the elbow and cephalic arch respectively. Half of the patients had chronic total occlusion of the outflow vein. Successful angioplasty was done in only two patients. Seven patients underwent ligation while one had spontaneous thrombosis of the fistula. None of the patients had regular surveillance of their access for a long time as they were not on dialysis. Unrecognized and uncorrected outflow stenosis over a long time period can lead to creation of mega fistula. Once a mega fistula develops there are not many treatment options other than ligation. This leads to loss of the access which might be needed in future. Continuous access surveillance in patients who are not on dialysis is important to prevent complications like mega fistula.

Perspectives in Individualizing Solutions for Dialysis Access.

The vascular access is the lifeline for the hemodialysis patient. Previous national vascular access guidelines have emphasized placement of arteriovenous fistulas in most hemodialysis patients. However, the new Kidney Disease Outcomes Quality Initiative guidelines for vascular access, soon to be published, will focus on a patient's end-stage kidney disease "life plan" and take a patient "first" approach. One of the major themes of the new Kidney Disease Outcomes Quality Initiative guidelines is selecting the "right access, for the right patient, at the right time, for the right reason". Given the availability of new advances in biomedical technologies, techniques, and devices in the vascular access field, this shift to a more patient-centered vascular access approach presents unique opportunities to individualize the solutions and care for patients requiring a dialysis vascular access. This review article will address 3 potential areas where there is an unmet need to individualize solutions for dialysis vascular access care: (1) biological approaches to improve vascular access selection and selection of therapies, (2) vascular access care for the post-transplant patient, and (3) vascular access disparities in race, gender, and the elderly patient.

Teriparatide Treatment for Hypercalcemia Associated With Adynamic Bone Disease.

Hypercalcemia most often results from primary hyperparathyroidism and malignancy. Adynamic bone disease (ABD) is a form of renal osteodystrophy characterized by reduced bone turnover, which can limit the ability of bone to release or store calcium, potentially leading to low, normal, or high serum calcium levels. We describe a 51-year-old dialysis-dependent female with hypercalcemia after parathyroidectomy. A demeclocycline-labeled bone biopsy confirmed adynamic bone disease. Teriparatide, a recombinant form of parathyroid hormone (PTH) used to treat postmenopausal osteoporosis, was prescribed for 12 months and normalized serum calcium levels. Although previous case reports and series have described favorable changes in spine bone mineral density when teriparatide was prescribed for ABD, ours is the first documented case in which teriparatide resolved hypercalcemia due to ABD. © 2019 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

Association of Pre-Transplant Dialysis Modality and Post-Transplant Outcomes: A Meta-Analysis.

♦ BACKGROUND: It remains unclear whether post-transplant outcomes differ according to the pre-transplant dialysis modality (peritoneal dialysis [PD] versus hemodialysis [HD]). We performed a meta-analysis of studies that assessed either post-transplant mortality, graft survival, or delayed graft function (DGF) in both PD and HD patients. ♦ METHODS: Two independent authors searched English-language literature from January 1, 1980, through August 31, 2014, national conference proceedings, and reference lists. We used combinations of terms related to dialysis (hemodialysis, peritoneal dialysis, or renal replacement therapy), kidney transplant, and outcomes. Studies were included if they measured any of the 3 post-transplant study outcomes in both pre-transplant HD and PD. ♦ RESULTS: A total of 16 studies were included in the final analysis. Of these, 6 studies reported adjusted hazard ratio for mortality, pooled adjusted risk ratio: 0.89 (95% confidence interval [CI] 0.82 - 0.97) in favor of PD (p = 0.006). The same 6 studies reported adjusted hazard ratio for graft survival, pooled adjusted risk ratio: 0.97 (95% CI 0.92 - 1.01, p = 0.16). A total of 13 studies reported unadjusted DGF. Pooled odds ratio: 0.5 (95% CI 0.41 - 0.63) in favor of PD (p < 0.005). Significant heterogeneity observed for all outcomes: I2 = 72.7%, I2 = 59.9%, and I2 = 66.8%, respectively. ♦ CONCLUSIONS: Based on these results, pre-transplant PD is associated with better post-transplant survival than HD. Pre-transplant PD was also associated with decreased risk for DGF compared with HD, although these results were unadjusted. There was no significant difference in graft survival between pre-transplant HD and PD. These results suggest that PD may be the preferred dialysis modality for patients expected to receive a transplant.

Hand Ischemia in a Patient With an Arteriovenous Fistula.

An ischemic digit causes significant morbidity due to its associated discomfort and potential for tissue necrosis. Historically, when this phenomenon was peripheral to an ipsilateral arteriovenous access in a hemodialysis patient, it was called "steal syndrome" and was usually treated with access ligation, resulting in loss of the access. We present a dialysis patient with hand pain due to ischemia that was referred for access ligation. Instead, a minimally invasive banding procedure was performed that resulted in access salvage and resolution of symptoms. We present images and a discussion of the diagnosis and treatment of distal hypoperfusion ischemia syndrome in this Imaging Teaching Case.

Erosion of the Silicone Peritoneal Dialysis Catheter with the Use of Gentamicin Cream at the Exit Site.

Infection remains the leading complication of peritoneal dialysis (PD). Topical mupirocin and gentamicin are frequently used to prevent infections. Mupirocin ointment has been reported to cause damage to both polyurethane and silicone PD catheters. Gentamicin cream has not been associated with physical damage to catheters.A 64-year-old woman on PD developed relapsing peritonitis with Staphylococcus epidermidis. Because of a drainage problem and white discoloration at the exit site, which is known as " frosting," she underwent catheter exchange. The catheter was found to be fractured within the area of frosting. Four more patients with frosting of the catheter were identified. On further questioning, it was recognized that they were applying excessive amounts of gentamicin cream directly on the catheter surface rather than at the exit site. All patients in the program were educated about the correct method of topical antibiotic application. After the change in practice, no further cases of catheter frosting were identified.Polyurethane catheters can undergo oxidation, mineralization, and environmental stress cracking, leading to physical damage such frosting, ballooning, and fracture. Polyethylene glycol, a component of the mupirocin ointment base, is thought to cause plasticization of polyurethane, reducing its tensile strength. Similar damage has been observed in silicone catheters. Previous reports have not found gentamicin cream to cause that type of damage. We observed that excessive amounts of cream applied directly to the catheter surface can damage it. Damage did not recur once patients had been educated about the proper method of application.

A Multi-Center, Randomized, Controlled, Pivotal Study to Assess the Safety and Efficacy of a Selective Cytopheretic Device in Patients with Acute Kidney Injury.

OBJECTIVE: Acute kidney injury (AKI) is a highly morbid condition in critically ill patients that is associated with high mortality. Previous clinical studies have demonstrated the safety and efficacy of the Selective Cytopheretic Device (SCD) in the treatment of AKI requiring continuous renal replacement therapy in the intensive care unit (ICU). DESIGN, SETTING, PATIENTS: A randomized, controlled trial of 134 ICU patients with AKI, 69 received continuous renal replacement therapy (CRRT) alone and 65 received SCD therapy. RESULTS: No significant difference in 60-day mortality was observed between the treated (27/69; 39%) and control patients (21/59; 36%, with six patients lost to follow up) in the intention to treat (ITT) analysis. Of the 19 SCD subjects (CRRT+SCD) and 31 control subjects (CRRT alone) who maintained a post-filter ionized calcium (iCa) level in the protocol's recommended range (≤ 0.4 mmol/L) for greater or equal to 90% of the therapy time, 60-day mortality was 16% (3/19) in the SCD group compared to 41% (11/27) in the CRRT alone group (p = 0.11). Dialysis dependency showed a borderline statistically significant difference between the SCD treated versus control CRRT alone patients maintained for ≥ 90% of the treatment in the protocol's recommended (r) iCa target range of ≤ 0.4 mmol/L with values of, 0% (0/16) and 25% (4/16), respectively (P = 0.10). When the riCa treated and control subgroups were compared for a composite index of 60 day mortality and dialysis dependency, the percentage of SCD treated subjects was 16% versus 58% in the control subjects (p<0.01). The incidence of serious adverse events did not differ between the treated (45/69; 65%) and control groups (40/65; 63%; p = 0·86). CONCLUSION: SCD therapy may improve mortality and reduce dialysis dependency in a tightly controlled regional hypocalcaemic environment in the perfusion circuit. TRIAL REGISTRATION: ClinicalTrials.gov NCT01400893 http://clinicaltrials.gov/ct2/show/NCT01400893.

Percutaneous versus surgical insertion of PD catheters in dialysis patients: a meta-analysis.

PURPOSE: Several small studies have suggested that the percutaneous method of peritoneal dialysis (PD) catheter insertion is effective and has a lower complication rate than surgical techniques (open, laparoscopic or peritoneoscopic), although no randomized, controlled study has compared these methods. Our objective was to compare percutaneous PD catheter insertion vs surgical placement in terms of 1-year catheter survival, catheter dysfunction, fluid leak and incidence of peritonitis. METHODS: We searched Medline for English-language literature from 1966 through June 2014, along with national conference proceedings and reference lists of all included publications to identify relevant studies. Inclusion criteria were having a measure of catheter survival at 1 year, catheter dysfunction, peritonitis rate per patient-month or fluid leak as outcomes. Studies were excluded if they were not in English or if they included pediatric patients. Random effects models were used to derive the pooled risk ratios, differences in patency and their variations. RESULTS: Thirteen studies with a total of 2,681 subjects met the inclusion criteria. There was no significant difference in 1-year catheter survival in percutaneous vs surgical PD catheter placement (relative risk [RR] = 0.81; 95% confidence interval [CI]: 0.59-1.11, p = 0.19). Catheter dysfunction also did not differ significantly between the groups (pooled odds ratio [OR] = 0.86; 95% CI: 0.57-1.29, p = 0.46). The prevalence of peritoneal fluid leak also was similar for percutaneous and surgical groups (OR = 1.10; 95% CI: 0.58-2.09, p = 0.77). However, there was a significant lower incidence of peritonitis among those with percutaneous placement (incidence rate ratio [IRR] = 0.77; 95% CI: 0.62-0.96, p = 0.02). Significant heterogeneity was detected across studies (I2 = 78.4%, p<0.0001). CONCLUSIONS: Our results suggest that there is no significant difference in catheter survival between percutaneous and surgical placement of PD catheters. Whether there are significant benefits from percutaneous placement in terms of peritonitis rates requires further robust studies. These findings have significant implications for future design of clinical trials in the placement of PD catheters and the delivery of dialysis-related services.

Prediction of Arteriovenous Fistula Dysfunction: Can it be Taught?

Physical examination (PE) is an excellent means of predicting arteriovenous fistula (AVF) dysfunction. Although quick and inexpensive, PE is seldom used as a tool to assess stenosis by general nephrologists, dialysis nurses, and dialysis technicians. Previous studies have demonstrated that PE can be taught to interventional specialists, but the perception remains that it is too complex to be performed by other health care professionals. We hypothesized that the physical exam can be taught to a nonmedical professional, and that, with time, it would be comparable to the physical exam performed by a full-time interventional specialist. An undergraduate student and an interventional specialist (MD) examined AVF for dysfunction in a tertiary care hospital over a 6-month period. PE was performed on patients who were suspected of having dialysis access dysfunction and were referred for angiography and intervention (n = 49). Physical exam findings were categorized blindly by each examiner into four categories of lesion location: inflow, outflow, both, or neither. Data were privately recorded and compared to the gold standard of angiographic results. Potential confounding variables, including age, gender, diabetic status, and location of AVF were recorded. Weighted Cohen's kappa value was used as a measurement of the level of agreement beyond chance between the diagnoses made by physical exam and angiography. The full-time interventional specialist demonstrated correct prediction of lesion location of 89.8% (kappa = 0.850), while the undergraduate student had a correct prediction of 77.6% (kappa = 0.625). The student's performance, however, differed significantly over time. The student correctly predicted the location of the lesion in 6 (42.9%) of the first 14 patients (kappa = 0.082), compared to 32 (91.4%) of the last 35 patients (kappa = 0.855). We suggest that physical exam of AVF can be taught to a nonmedical professional in a short duration of time and the predictive value of the exam can be similar to that of an interventional specialist.

Hemodialysis catheter locking solutions and the prevention of catheter dysfunction: a meta-analysis.

PURPOSE: Tunneled dialysis catheters (TDCs) continue to be utilized at an alarming rate despite having a higher rate of complications when compared to fistulas and grafts. One of the primary complications of TDCs involves catheter dysfunction resulting in reduced blood flow and poor dialysis adequacy, often requiring catheter removal in addition to thrombolytic therapy. Our objective was to compare the use of locking solutions containing heparin versus all other locking solutions for primary prevention of TDC dysfunction. METHODS: We searched Medline for English language literature from 1980 through December 2013, along with national conference proceedings and reference lists of all included publications to identify relevant studies. Inclusion criteria were a measure of incidence of catheter dysfunction, catheter exchange or use of thrombolytic therapy. Studies were excluded if they were not in English or if they included pediatric patients. Random effects models were used to derive the pooled risk ratios. RESULTS: Thirteen studies with a total of 1,883 subjects met the inclusion criteria. There was no significant difference in catheter patency in those receiving heparin versus those treated with other lock solutions (incidence rate ratio [IRR] 0.99; 95% confidence interval [CI] 0.66-1.48, p = 0.96). Catheter patency did not differ between treatments in experimental studies (n = 10; IRR = 0.89; 95% CI: 0.56-1.39, p = 0.60) or observational design (n = 3; IRR = 1.64; 95% CI 0.40-6.85, p = 0.50). Significant heterogeneity was detected across studies (I2 = 84.4%, p<0.001). CONCLUSIONS: Our results suggest that there is no substantial difference between heparin lock solutions versus all other types of catheter lock solutions for catheter dysfunction. Whether there are significant benefits of citrate or other novel lock solutions requires further robust studies. These findings have significant implications for future design of clinical trials in TDCs and the delivery of dialysis-related services.

Tunneled dialysis catheter exchange with fibrin sheath disruption is not associated with increased rate of bacteremia.

PURPOSE: Tunneled dialysis catheters are the most common form of vascular access among incident dialysis patients in the United States. Fibrin sheath formation is a frequent cause of late catheter dysfunction requiring an exchange procedure with balloon disruption of the fibrin sheath. It is unknown whether fibrin sheath disruption is associated with increased incidence of bacteremia or catheter failure. METHODS: We reviewed all tunneled dialysis catheter exchange procedures at the University of Wisconsin between January 2008 and December 2011. The primary outcome was incidence of bacteremia, defined as positive blood cultures within 2 weeks of the procedure. Catheter failure, requiring intervention or replacement, was examined as a secondary outcome. Baseline characteristics examined included diabetic status, gender, race and age. RESULTS: A total of 163 procedures were reviewed; 67 (41.1%) had fibrin sheath disruption and 96 did not. Bacteremia occurred in 4.5% (3/67) of those with and 3.1% (3/97) of those without fibrin sheath disruption (p=0.65). Fibrin sheath disruption was not significantly associated with the risk of catheter failure (adjusted hazard ratio [aHR]=1.34; 95% confidence interval [CI]: 0.87-2.10; p=0.18). Diabetes was associated with greater risk of catheter failure (aHR=1.88; 95% CI: 1.19-2.95; p=0.006), whereas higher age was associated with a lower risk of catheter failure (aHR per 10 years=0.83; 95% CI: 0.72-0.96; p=0.01). CONCLUSIONS: This study demonstrates that there is no significant increase in bacteremia and subsequent catheter dysfunction rates after fibrin sheath disruption compared to simple over the wire exchange. These results are encouraging given the large numbers of patients utilizing tunneled catheters for initial hemodialysis access and the known rates of fibrin sheath formation leading to catheter failure.

Dialysis access venous stenosis: treatment with balloon angioplasty 30-second vs. 1-minute inflation times.

Percutaneous balloon angioplasty is the standard of care in the endovascular treatment of dialysis access venous stenosis. The significance of balloon inflation times in the treatment of these stenoses is not well defined. Our objective was to examine the outcomes of 30-second vs. 1-minute balloon inflation times on primary-assisted patency of arteriovenous fistulae and grafts. Using a prospectively collected vascular access database, we identified a total of 75 patients referred for access dysfunction during a 5-year period. These patients received 223 interventions (178 with 30-second inflations and 45 with 1-minute inflations). We compared primary-assisted patency during the subsequent 9 months across groups defined by inflation times. Demographics and baseline characteristics were similar across groups. Immediate technical success and patency in the first 3 months were similar across groups (hazard ratio [HR] = 0.86; 95% confidence interval [CI]: 0.34-2.20). After 3 months, however, a 1-minute inflation time was associated with greater incidence of access failure (adjusted HR [aHR] = 1.74; 95% CI: 1.09-2.79). Other predictors of access failure included age over 60 (aHR = 1.02; 95% CI: 1.01-1.04), central location of the lesion (aHR = 2.49; CI: 1.27-4.89), and three or more prior procedures (aHR 2.48; CI: 1.19-5.16). Our data suggest that shorter balloon inflation times may be associated with improved longer term access patency, although the benefit was not observed until after 3 months. Given the increasing demands of maintaining access patency in the era of the National Kidney Foundation Kidney Disease Outcomes Quality Initiative and Fistula First, the role of angioplasty times requires further study.

A Meta-analysis of Stent Placement vs. Angioplasty for Dialysis Vascular Access Stenosis.

Dysfunction of arteriovenous fistulas (AVF) and arteriovenous grafts (AVG) contribute significantly to morbidity and hospitalization in the dialysis population. Despite advances in endovascular techniques, the incidence of vascular access stenosis remains problematic. Currently, the role of endovascular stent placement in the treatment of vascular access stenosis is poorly defined. This meta-analysis compares the primary patency rates of stenotic vascular access treated with stent placement vs. angioplasty. We searched Medline for English language publications from 1980 through December 2013, along with national conference proceedings and reference lists of all included publications. Inclusion criteria were a measure of primary patency, secondary patency, or access dysfunction. Studies were excluded if they were not in English or if they included pediatric patients. Ten studies with a total of 860 subjects met the inclusion criteria, including six experimental studies and four observational studies. There was significantly higher overall primary patency in those receiving stent placement than in those treated with angioplasty (pooled relative risk [RR] = 0.79; 95% confidence interval [CI]: 0.65-0.96). The estimate did not differ by study design. The effect of treatment differed significantly (p = 0.001) by the type of stents used, however. In studies including nitinol stents (six studies, 678 patients), 6-month patency was significantly better for stent placement than angioplasty (pooled RR = 0.67; 95% CI: 0.54-0.84), whereas there was no significant differences between stent placement and angioplasty in those studies using bare metal stents exclusively (four studies, 182 patients; pooled RR = 1.09; 95% CI: 0.91-1.32). There was significant heterogeneity between studies (I(2)  = 70.6%; p < 0.0001). Our results suggest that stent placement may confer an advantage over balloon angioplasty in primary patency of dialysis access stenoses.

Pilot Study of the Effect of Lanthanum Carbonate (Fosrenol®) In Patients with Calciphylaxis: A Wisconsin Network for Health Research (WiNHR) Study.

BACKGROUND: Currently there is a lack of effective treatment options for patients with calciphylaxis. There is anecdotal evidence that non-calcium based phosphorus binders may offer some benefit. The aim of this pilot study is to determine if lanthanum carbonate is effective in inducing remission of calciphylaxis lesions and demonstrate an improved DLQI (Dermatology Life Quality Index). METHODS: This is a multi-site exploratory pilot study conducted through the Wisconsin Network for Health Research (WiNHR), a collaboration of health services researchers across the state of Wisconsin. Dialysis patients were recruited from in-center dialysis units, clinics and hospital admissions over a period of 24-months. RESULTS: Due to the low inclusion rate, the trial was terminated after which 4 patients were prospectively analyzed. Dose of lanthanum carbonate was escalated to 3750 mg divided into 3 meals and titrated according to level of serum phosphorus. Gastrointestinal symptoms were the most common adverse effect. All 4 patients achieved complete remission by definition of skin re-epithelialization. Secondary outcome measurements showed a significant improvement in serum albumin (B coeff 0.17, 95% CI 0.002-0.031; p=0.023) and a significant improvement in overall DLQI score (B coeff -0.46, 95% CI -0.85- -0.08; p=0.019). CONCLUSIONS: Lanthanum carbonate appears to be efficacious as an adjunctive therapy to improve calciphylaxis lesions and symptom burden. More prospective clinical trials are warranted to determine the feasibility of this novel treatment strategy.

Initial vascular access type in patients with a failed renal transplant.

BACKGROUND AND OBJECTIVES: Permanent hemodialysis vascular access is crucial for RRT in ESRD patients and patients with failed renal transplants, because central venous catheters are associated with greater risk of infection and mortality than arteriovenous fistulae or arteriovenous grafts. The objective of this study was to determine the types of vascular access used by patients initiating hemodialysis after a failed renal transplant. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Data from the US Renal Data System database on 16,728 patients with a failed renal transplant and 509,643 patients with native kidney failure who initiated dialysis between January 1, 2006, and September 30, 2011 were examined. RESULTS: At initiation of dialysis, of patients with a failed transplant, 27.7% (n=4636) used an arteriovenous fistula, 6.9% (n=1146) used an arteriovenous graft, and 65.4% (n=10,946) used a central venous catheter. Conversely, 80.8% (n=411,997) of patients with native kidney failure initiated dialysis with a central venous catheter (P<0.001). Among patients with a failed transplant, predictors of central venous catheter use included women (adjusted odds ratio, 1.75; 95% confidence interval, 1.63 to 1.87), lack of referral to a nephrologist (odds ratio, 2.00; 95% confidence interval, 1.72 to 2.33), diabetes (odds ratio, 1.14; 95% confidence interval, 1.06 to 1.22), peripheral vascular disease (odds ratio, 1.31; 95% confidence interval, 1.16 to 1.48), and being institutionalized (odds ratio, 1.53; 95% confidence interval, 1.23 to 1.89). Factors associated with lower odds of central venous catheter use included older age (odds ratio, 0.85 per 10 years; 95% confidence interval, 0.83 to 0.87), public insurance (odds ratio, 0.74; 95% confidence interval, 0.68 to 0.80), and current employment (odds ratio, 0.87; 95% confidence interval, 0.80 to 0.95). CONCLUSIONS: Central venous catheters are used in nearly two thirds of failed renal transplant patients. These patients are usually followed closely by transplant physicians before developing ESRD after a failed transplant, but the relatively low prevalence of arteriovenous fistulae/arteriovenous grafts in this group at initiation of dialysis needs to be investigated more thoroughly.