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The purpose of this article is to assess the performance and safety of a novel, symmetric, side-hole–free tunneled cuffed catheter hypothesized to sustain adequate flow without the need for side holes. Between November 2016 and January 2019, Pristine hemodialysis catheters were placed de novo in 45 end-stage renal disease patients (27 males and 18 females) at a single investigational site. Forty-one catheters were placed in the right and four in the left internal jugular vein. There were no incidents of insertion failure. Patients had dialysis three times per week and were followed at four investigational sites. Nominal catheter flows, incidence of poor flow, and catheter-related infections were recorded at each dialysis session and analyzed. The average follow-up time was 161.69 days for a total of 7116 catheter days. Nine patients died from reasons unrelated to the catheter and one patient switched to fistula. Four patients had poor flows necessitating catheter replacement. Four patients had catheter-related bloodstream infections which resolved with antibiotics. These equate to 0.56 events per 1000 catheter days. Catheter survival was 100%, 97.6%, and 89.7% at 30, 90, and 180 days, respectively. The initial clinical assessment of the symmetric Pristine hemodialysis catheter featuring a Y-tip devoid of side holes revealed good catheter performance and survival and a low complication rate.

Background: Eighty percent of hemodialysis patients start their dialysis with a tunneled hemodialysis catheter. Catheter related bacteremia is the second most common cause of death in these patients. Side holes near the tips of the tunneled cuffed central venous catheters are associated with accumulation of thrombus, which can lead to catheter dysfunction and, possibly, also to catheter-related infection. To assess the hypothesis that a catheter without side holes would be associated with less bacterial growth, this study compared the susceptibility of a side-hole-free catheter to accumulation of pathogenic bacteria at the catheter tip with that of two catheters which have side holes. Methods: Eight tunneled cuffed double-lumen central venous catheters were inserted into both jugular veins of four sheep; one side-hole-free and one control catheter with side holes at the tip in each animal. Staphylococcus aureus bacteria were then infused intravenously to cause bacteremia. Six hours later, the catheters were removed, the clots that accumulated in their tips were collected and cultured, and the bacterial colonies were counted after additional 12 h of incubation. Results: Bacteria grew on culture plates seeded with the clot homogenate obtained from the tips of all catheters. The colony counts from the catheters with side holes at the tip exceeded the colony counts of bacteria accumulated in the tips of the side-hole-free hemodialysis catheters by one or more orders of magnitude, with a difference of at least two orders of magnitude observed in three of the four intra-animal comparisons. Conclusions: In paired intra-animal post-inoculation comparison made in this limited study, fewer colony forming units of pathogenic bacteria accumulated at the tip of the side-hole-free catheters than at the tips of the catheters which have side holes. This may translate to a decreased rate of catheter-related blood stream infections in the side-hole-free catheters.

Tunneled central venous catheters (TCVCs) are colonized by Gram-positive organisms and form biofilm. Lipoteichoic acid (LTA) is a Gram-positive cell wall component that can be measured in serum. The purpose of this pilot study was to characterize LTA concentrations in hemodialysis (HD) patients with TCVCs compared to other access types and to evaluate biofilm morphology and microbiology in TCVCs removed by clinical decision. The study enrolled patients with TCVCs (18), grafts (19), and fistulas (18). Blood samples were collected before HD, at 30 minutes, 2 hours, and end of HD. Catheters removed by clinical decision were evaluated by scanning electron microscopy (SEM) for biofilm morphology, and portions of the catheter were cultured. LTA was detectable in all samples and concentrations increased significantly in all access types during HD (p0.05 for all comparisons). Patients with TCVCs that had a30% increase in LTA concentration from baseline also had the greatest rate of increase (slope) compared to grafts and fistulas (p = 0.03 and p = 0.04, respectively). Catheters removed by clinical decision (n = 7) and examined by SEM had deposition of fibrin. Cultures revealed polymicrobial colonization. TCVCs had the highest rate of increase of LTA during HD. Further studies to determine the source of LTA in patients with AVG and AVF are warranted.

The National Kidney Foundation's Kidney Disease Outcomes Quality Initiative (KDOQI) has provided evidence-based guidelines for hemodialysis vascular access since 1996. Since the last update in 2006, there has been a great accumulation of new evidence and sophistication in the guidelines process. The 2019 update to the KDOQI Clinical Practice Guideline for Vascular Access is a comprehensive document intended to assist multidisciplinary practitioners care for chronic kidney disease patients and their vascular access. New topics include the end-stage kidney disease "Life-Plan" and related concepts, guidance on vascular access choice, new targets for arteriovenous access (fistulas and grafts) and central venous catheters, management of specific complications, and renewed approaches to some older topics. Appraisal of the quality of the evidence was independently conducted by using a Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach, and interpretation and application followed the GRADE Evidence to Decision frameworks. As applicable, each guideline statement is accompanied by rationale/background information, a detailed justification, monitoring and evaluation guidance, implementation considerations, special discussions, and recommendations for future research.

Despite substantial efforts by nephrology community to reduce utilization of dialysis catheters, majority of end-stage renal disease patients in the USA initiate hemodialysis (HD) with a tunneled dialysis catheter (TDC) with approximately one-quarter of them remaining catheter-dependent thereafter. TDCs are associated with decreased patient survival, as well as multiple complications, such as central venous stenosis, infection, and thrombosis. In this chapter, we provide a general approach to evaluating a poorly functioning TDC at a dialysis unit and an interventional suite, as well as treatment strategies directed at specific TDC-related complications.

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.

The use of tunneled dialysis catheters (TDCs) for patients in need of hemodialysis treatments (HDs) causes a significant number of bloodstream infections (BSIs), with very few viable preventative/treatment methods. Use of antibiotics is relatively ineffective due to the development of multidrug-resistant bacterial strains and the inability to penetrate bacterial biofilms. Nitric oxide (NO) is an endogenous gas molecule that has broad-spectrum antimicrobial/antibiofilm activity. In this study, the potential of creating a NO-releasing insert device that is attached onto the hub region cap of TDCs and locally releases NO within the TDC hub is evaluated for its antimicrobial/antibiofilm effectiveness. The NO-releasing insert contains the natural NO donor S-nitrosoglutathione (GSNO), along with zinc oxide (ZnO) nanoparticles to accelerate NO release from the GSNO, within a short silicone tube that is sealed at both ends and attached to the catheter cap. An in vitro 3-d-long antimicrobial study using catheter hubs yielded >6.6 log reductions of both Pseudomonas aeruginosa and Staphylococcus aureus for the NO-releasing insert device compared to controls. Two 14-d-long sheep studies demonstrated that the NO-releasing insert devices are exceptionally potent at preventing bacteria/biofilm growth on the inner lumen walls of TDCs compared to controls that have no preventative treatment devices as well as implanted TDCs that have commercially available chlorhexidine-treated insert devices placed within the hub regions.

Background: Arteriovenous (AV) access dysfunction is a common complication in hemodialysis patients. Markers of vascular calcification are associated with cardiovascular outcomes and mortality in this population, but their association with vascular access outcomes is unknown. In this study, we aimed to evaluate the association between selected vascular calcification makers and vascular access complications in a cohort of hemodialysis patients. Method: Fetuin-A, osteopontin (OPN), osteoprotegerin (OPG), and bone morphogenetic protein-7 (BMP-7) were measured in blood samples from 219 dialysis patients in the Choice for Healthy Outcomes in Caring for end-stage renal disease study; these patients were using a permanent vascular access. Participants were followed for up to 1 year or until the occurrence of a vascular access intervention or replacement. Associations with AV fistula (AVF) and AV graft (AVG) intervention-free survival were assessed in models adjusted for demographic characteristics, comorbidities, and inflammation. Results: A total of 24 out 103 participants with an AVF and 43 out of 116 participants with an AVG had an intervention during follow-up. Lower fetuin-A, higher OPN, and higher BMP-7 were associated with a higher risk of AVF intervention (adjusted hazard ratios [aHR] for highest versus lowest tertile = 0.30 [95% CI 0.10–0.94]) for fetuin-A, 3.84 (95% CI 1.16–12.74) for OPN, and 3.49 (95% CI 1.16–10.52) for BMP-7. OPG was not significantly associated with the risk of AVF intervention. The associations of OPN and BMP-7 with AVF intervention appeared stronger among participants without diabetes (aHR 8.06; 95% CI 1.11–58.57 for OPN and aHR 2.55; 95% CI 1.08–6.08 for BMP-7, respectively) than among their counterparts with diabetes (p interaction = 0.06). None of the markers studied were significantly associated with AVG interventions. Conclusion: Lower fetuin-A and higher OPN and BMP-7 are associated with complications in AVF but not in AVG, suggesting a role for calcification in the pathogenesis AVF failure.

Rationale & objective Creation of an arteriovenous fistula (AVF), compared to an AV graft (AVG), is associated with longer initial catheter dependence after starting hemodialysis 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 United States Renal Data System (USRDS) who had a first AVF (n=14,532) or AVG (n=3391) placed within 1 year after HD initiation between May 2012 and May 2017. Exposure AVF versus AVG placement in first year of hemodialysis. 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 was associated with greater catheter dependence at one month (95.6% vs. 92.5%) and at three months (82.8% vs. 41.2%), but lower catheter dependence at 12 months (14.2% vs. 15.8%) and at 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 three 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 dependency of an AVF are not realized in many elderly patients, specific patient characteristics should be considered when making decisions regarding vascular access.

Background: Tunneled hemodialysis catheter-related bloodstream infection is a major cause of morbidity and mortality in end-stage renal disease patients. Side holes positioned near the tip of catheters have been linked to formation of thrombi, which, in turn, have been implicated in predisposition to infection. In addition, side holes allow spillage of catheter locking solution, including antibiotics, thereby minimizing the lock solution’s effect on the catheter tip. This study assessed the infection events that occurred in a series of hemodialysis patients using a non-side-hole catheter. Methods: Over a period of 2 years, a novel symmetric-tip non-side-hole catheter was placed in 60 patients. Hemodialysis was performed thrice weekly. Prescribed dialyzer flows were 300–350 mL/min. Catheters were routinely locked with heparin 5000 units/mL between treatments. Patients were followed up for any catheter related complications, specifically infection events. Results: Seven events of catheter-related bloodstream infection occurred for a rate of 0.76 events per 1000 catheter-days, with the first event occurring 9 weeks after insertion. These events were treated by locking the affected catheter with 2 g of clindamycin in 2 mL of heparin 1000 units/mL and administration of intravenous antibiotics, in most cases, for 7–14 days. Two catheters were removed due to infection. Conclusions: Catheter-related bloodstream infections with non-side-hole hemodialysis catheters do occur at a relatively low rate and in this initial preliminary study it seems that most of these infections can be successfully treated without removal of the affected catheters.

PurposeTo assess the safety and efficacy of an expanded polytetrafluoroethylene stent graft versus balloon angioplasty for the treatment of in-stent restenosis in the venous outflow of hemodialysis access grafts and fistulae.Materials and MethodsTwo hundred seventy-five patients were randomized at 23 US sites to stent-graft placement or percutaneous transluminal angioplasty (PTA). Primary study endpoints were access circuit primary patency (ACPP) at 6 months and safety through 30 days; secondary endpoints were evaluated through 24 months.ResultsACPP at 6 months was significantly higher in the stent-graft group (18.6%) versus the PTA group (4.5%; P < .001), and freedom from safety events (30 days) was comparable (stent graft, 96.9%; PTA, 96.4%; P = .003 for noninferiority). The separation in ACPP survival curves remained through 12 months (stent graft, 6.2%; PTA, 1.5%). Treatment area primary patency (TAPP) was superior for the stent-graft group (66.4%) versus the PTA group (12.3%) at 6 months (P < .001), with a survivorship difference in favor of stent-graft placement maintained through 24 months (stent graft, 15.6%; PTA, 2.2%). ACPP and TAPP for the stent-graft group were better than those for the PTA group when compared within central and peripheral vein subgroups (P < .001). In central veins, TAPP was 13.6% in the stent-graft group versus 4.3% in the PTA group at 24 months (P < .001).ConclusionsStent-graft use provided better ACPP and TAPP than PTA when treating in-stent restenosis in patients receiving dialysis with arteriovenous grafts and fistulae.

Patients with end-stage renal disease (ESRD) on chronic hemodialysis (HD) suffer accelerated morbidity and mortality rates caused by cardiovascular disease and infections. Chronic inflammation plays a critical role in these poor outcomes. The activated monocyte (MO) has become a prime therapeutic target to modulate this inflammatory process. A selective cytopheretic device (SCD) was evaluated to assess its effects on the circulating MO pool. A pilot trial was undertaken in 15 ESRD patients on HD with C-reactive protein (CRP) levels greater than 5 mg/dl. An excellent safety profile was observed with no decline in leukocyte (LE) or platelet counts. The effect of SCD therapy on MO phenotypes in these patients was determined on peripheral blood MO utilizing flow cytometry. SCD therapy promoted a shift in MO phenotype from predominantly CD14hi expressing MO at baseline/pre-SCD therapy to CD14low expressing MO post-SCD therapy. A significant shift in MO population phenotype afforded by a single SCD therapy session was observed (p < 0.013). In a subset of patients (n = 7) presenting with type 2 diabetes mellitus (T2D), this persistent decline in MO CD14 expression was sustained as long as 2 weeks posttherapy. These results demonstrate that the SCD therapy has the potential to modulate the chronic proinflammatory state in ESRD patients.

Vascular access dysfunction is a major cause of morbidity in patients with end-stage renal disease (ESRD) on chronic hemodialysis. The effects of abnormalities in mineral metabolism on vascular access are unclear. In this study, we evaluated the association of mineral metabolites, including 25-hydroxy vitamin D (25(OH)D) and fibroblast growth factor-23 (FGF-23), with vascular access complications.We included participants from the Choices for Healthy Outcomes in Caring for ESRD (CHOICE) Study who were using an arteriovenous fistula (AVF; n = 103) or arteriovenous graft (AVG; n = 116). Serum levels of 25(OH)D, FGF-23, parathyroid hormone (PTH), calcium, phosphorus, C-reactive protein (CRP) and interleukin-6 (IL-6) were assessed from stored samples. Participants were followed for up to 1 year or until a vascular access intervention or replacement.A total of 24 participants using an AVF and 43 participants using an AVG experienced access intervention. Those with 25(OH)D level in the lowest tertile (11 ng/mL) had an increased risk of AVF intervention compared to those with higher 25(OH)D levels (adjusted relative hazard [aHR] = 3.28; 95% confidence interval [CI]: 1.31, 8.20). The highest tertile of FGF-23 (3750 RU/mL) was associated with greater risk of AVF intervention (aHR = 2.56; 95% CI: 1.06, 6.18). Higher PTH was associated with higher risk of AVF intervention (aHR = 1.64 per SD of log(PTH); 95% CI: 1.02, 2.62). These associations were not observed in participants using an AVG. None of the other analytes were significantly associated with AVF or AVG intervention.Low levels of 25(OH)D and high levels of FGF-23 and PTH are associated with increased risk of AVF intervention. Abnormalities in mineral metabolism are risk factors for vascular access dysfunction and potential therapeutic targets to improve outcomes.

Purpose A lengthy healing and maturation period follows standard surgical preparation of a permanent arteriovenous access, often requiring or extending use of a venous catheter (VC) for hemodialysis. The InterGraft™ Anastomotic Connector System was developed for minimally invasive anastomosis of an arteriovenous graft (AVG). The venous and arterial InterGraft™ connectors are designed to provide optimized flow dynamics and may result in reduction of AVG stenosis. This pilot study evaluated placement procedure success, patency and safety of the InterGraft™ connectors. Methods Nine AVGs were implanted in nine patients currently receiving dialysis with a VC. The study allowed use of both connectors (n = 5) or use of the venous connector with a sutured arterial anastomosis (n = 4). Monthly ultrasound examinations were performed throughout the six-month follow-up. AVG angiography was performed at five months. Endpoints included procedure success (acceptable graft flow at end of procedure, without significant bleeding or need for emergent surgery), patency, and device-related major adverse events. Results Procedure success was attained in all patients. AVGs were used for dialysis within 17 days, on average, and VCs were removed. Three patients exited the study early for reasons unrelated to the InterGraft™ connectors. The remaining six patients had patent grafts: two with assisted and four with unassisted patency. AVG flow rates were greater than 1 L/minute. No dilatations or aneurysms were observed by angiography. There were no device-related major adverse events. Conclusions The InterGraft™ connectors can be safely and successfully used for AVG anastomoses, with acceptable near-term patency. Further clinical evaluation is warranted.

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%, pConclusions 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.

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.

Historically, the placement and maintenance of dialysis access has been an integral part of nephrology training. However, in recent years, a big debate has ensued regarding whether this should be limited to trainees' understanding and counseling the patients regarding indications, alternatives, risks and possible complications of these procedures or should it actually involve more of a hands-on experience for the trainees. Some of the barriers in making these procedures a requirement across the board are the lack of standardization of procedural training across various training programs and the absence of consensus on what achieving competency in these procedures looks like. However, in the era of declining interest in nephrology, giving up "ownership" of nephrology procedures and increasing reliance on other sub specialties might be a deterrent in attracting residents to this field; we have to make a concerted effort to increase the exposure and opportunities for the trainees to perform these procedures. Moreover, we need to emphasize the implementation of a curriculum for nephrology fellows to evaluate access properly in order to decrease the burden of access related complications. Lastly, we need to continue working towards a more structured curriculum for a dedicated interventional nephrology fellowship for trainees who want to focus on procedures for their long-term career goals.

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%, pConclusions 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.

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.

Congestive heart failure (CHF) is an important source of morbidity and mortality in end-stage renal disease patients. Although CHF is commonly associated with low cardiac output (CO), it may also occur in high CO states. Multiple conditions are associated with increased CO including congenital or acquired arteriovenous fistulae or arteriovenous grafts. Increased CO resulting from permanent AV access in dialysis patients has been shown to induce structural and functional cardiac changes, including the development of eccentric left ventricle hypertrophy. Often, the diagnosis of high output heart failure requires invasive right heart monitoring in the acute care setting such as a medical or cardiac intensive care unit. The diagnosis of an arteriovenous access causing high output heart failure is usually confirmed after the access is ligated surgically. We present for the first time, a case for real-time hemodynamic assessment of high output heart failure due to AV access by interventional nephrology in the cardiac catheterization suite.

The rope-ladder (RL) technique is the most common technique used for cannulation of arteriovenous fistulae (AVF). Buttonhole cannulation (BHC), or constant-site technique, is recommended by the National Kidney Foundation's Kidney Disease Outcome Quality Initiative (NKF/KDOQI) vascular access guidelines. We compared outcomes of primary patency, episodes of bacteremia, access blood flow (Qa), and quality of life (QoL) scores between RL and BHC patients. Using a prospectively collected, vascular access database, a total of 45 prevalent dialysis patients using BHC were compared with 38 patients using the RL technique over a median of 12 months (inter-quartile range: 4-27 months). The two groups did not differ significantly in demographics except that diabetes was more common in those using BHC as compared to rope-ladder (69% vs. 34%; p = 0.002). Risk factors associated with lack of primary patency were age (hazards ratio [HR] = 1.02 per decade; 95% CI: 1.00-1.03; p = 0.04) and female gender (HR = 1.92; 95% CI: 1.08-3.40; p = 0.03). Use of the buttonhole technique was not associated with improved primary patency (HR = 1.22, 95% CI: 0.65-2.28; p = 0.53). Episodes of bacteremia and mean scores from KDQOL-36 did not differ significantly between the groups. This study demonstrates for the first time that BHC use is not associated with improved access patency.

The minimal decrease in cardiac output with occlusion of the fistula and evidence suggested that the arteriovenous fistula was not contributing to the patient’s heart failure. Intriguingly, she did have multiple areas of dilation with tortuosity generating a natural flow reduction. The decision was made to proceed with the mitral valve replacement but leave the AVF in place.

This chapter discusses the case of a patient with a left upper-arm arteriovenous fistula (AVF) that was referred for evaluation of left hand pain on hemodialysis. A detailed history and physical examination ruled out the possibility of nonischemic hand pain due to carpal tunnel syndrome or neuropathy. Preoperative evaluation revealed poor distal pulses in the left hand, as well as the contralateral arm.

This chapter discusses the case of a patient with focal arterial lesion of the upper extremity. Recent data have emphasized that significant (≥50%) arterial stenoses are commonly seen in dialysis patients presenting with symptoms of hand ischemia. These lesions can occur anywhere within the arteries of the upper extremities including the proximal arteries and have been demonstrated to cause peripheral ischemia in haemodialysis (HD) patients. Using arteriography, the incidence of arterial stenosis in patients with peripheral ischemia has been reported to range from 62% to 100%. Arteriography is the most important tool in making the diagnosis as well as developing a treatment strategy for hand ischemia.

This chapter addresses the case presentation of a 55-year-old woman, who was diagnosed with IgG lambda multiple myeloma and was referred to Interventional Nephrology for evaluation of arm swelling on the ipsilateral side of a recently created arteriovenous fistula (AVF). She had been receiving hemodialysis for the past 3 months via right internal jugular vein tunneled catheter. Two prior left upper extremity attempts at AVF placement had failed. A right upper extremity brachial artery to cephalic vein perforator AVF was created several weeks prior to presentation.

This chapter discusses the case of a patient with a glomerular filtration rate (GFR) of 7 ml/min who was referred to Interventional Nephrology for placement of a tunneled hemodialysis catheter due to the onset of uremic symptoms.

This chapter discusses the case of a patient with end-stage renal disease (ESRD) who presented with a femoral tunneled hemodialysis catheter that “fell out.” The patient has had multiple previous access surgeries and multiple central catheters with known left and right subclavian vein occlusion. She had been dialyzing via right femoral tunneled catheter for the past 3 months with no infectious complications noted. The patient is known to have a contrast allergy.

This chapter discusses the case of a patient referred for hemodialysis initiation in the setting of multiple myeloma requiring chemotherapy.

This chapter discusses the case of a patient with type I diabetes since early childhood who presented with an infected groin hemodialysis (HD) catheter. She had multiple failed HD and peritoneal dialysis (PD) accesses and was not a transplant candidate due to a high panel reactive antibody (PRA).

Acute kidney injury (AKI) is characterized by deterioration in kidney function resulting in multisystem abnormalities. Much of the morbidity and mortality associated with AKI result from a systemic inflammatory response syndrome (SIRS). This study described herein is a prospective, single-arm, multicenter US study designed to evaluate the safety and efficacy of the Selective Cytopheretic Device (SCD) treatment on AKI requiring continuous renal replacement therapy (CRRT) in the ICU. The study enrolled 35 subjects. The mean age was 56.3 ± 15. With regard to race, 71.4% of the subjects were Caucasian, 22.9% were Black, and 5.7% were Hispanic. Average SOFA score was 11.3 ± 3.6. Death from any cause at Day 60 was 31.4%. Renal recovery, defined as dialysis independence, was observed in all of the surviving subjects at Day 60. The results of this pilot study indicate the potential for a substantial improvement in patient outcomes over standard of care therapy, which is associated with a greater than 50% 60-day mortality in the literature. The SCD warrants further study in scientifically sound, pivotal trial to demonstrate reasonable assurance of safety and effectiveness.

Peripheral arterial disease (PAD) is a cardiovascular disease risk equivalent and is a common problem in chronic kidney disease patients. Unlike in the general population, PAD in CKD occurs due to medial calcification as opposed to intimal atherosclerotic process. PAD intervention should be performed in select symptomatic patients, as described by the guidelines, and CVD risk factor modification should occur in all CKD patient, regardless of the presence of PAD. As a discipline, Interventional Nephrology has emerged out of a desire to create better outcomes for our patients and to "fix a problem." The core values of our discipline have evolved out of this fundamental desire to meet an unmet clinical need, to provide insight into a disease state specific to our patients, and to offer clinical/academic excellence in doing so. We must endeavor to follow a similar path in our approach to PAD. The purpose of this review is to educate interventional nephrologists in the diagnosis and treatment of PAD in their CKD patients.

Conventional treatment of acute and chronic renal diseases has focused on solute removal. Novel strategies aim to treat the multifactorial disease states of acute kidney injury and chronic kidney disease by mitigating inflammation. Cell-based technologies for the treatment of kidney dysfunction fall under two broad categories: cell therapy and cell processing. Cell therapy utilizes cells that are isolated, cultured outside of the body, and reintroduced as therapy, leveraging beneficial metabolic and synthetic functions. For example, renal tubule cells have been used to provide gluconeogenesis, ammoniagenesis, metabolism of glutathione, catabolism of important peptide hormones, growth factors, and cytokines critical to multiorgan homeostasis and immunomodulation to treat renal dysfunction. Cell processing focuses on altering the characteristics of cell populations inside the body to provide therapy. The selective cytopheretic device is an example of this novel therapeutic strategy that aims to modulate the innate immune response during organ dysfunction, additional organ injury, by binding and deactivating leukocytes. In this review, both cell therapy and cell processing approaches will be discussed in the context of acute kidney injury and chronic renal disease.

The development of interventional nephrology has undoubtedly led to an improvement in patient care at many facilities across the United States. However, these services have traditionally been offered by interventional nephrologists in the private practice arena. While interventional nephrology was born in the private practice setting, several academic medical centers across the United States have now developed interventional nephrology programs. University Medical Centers (UMCs) that offer interventional nephrology face challenges, such as smaller dialysis populations, limited financial resources, and real or perceived political "turf" issues." Despite these hurdles, several UMCs have successfully established interventional nephrology as an intricate part of a larger nephrology program. This has largely been accomplished by consolidating available resources and collaborating with other specialties irrespective of the size of the dialysis population. The collaboration with other specialties also offers an opportunity to perform advanced procedures, such as application of excimer laser and endovascular ultrasound. As more UMCs establish interventional nephrology programs, opportunities for developing standardized training centers will improve, resulting in better quality and availability of nephrology-related procedures, and providing an impetus for research activities.

Purpose The right internal jugular (RIJ) vein is preferred for placement of long-term venous catheters (CVC) for hemodialysis (HD). Use of left IJ vein potentially depletes the access site for arteriovenous fistula (AVF) or arteriovenous graft (AVF) placement because of the high rates of central venous stenosis. The right external jugular (EJ) vein is a viable alternative to the LIJ. The purpose of this study is to compare blood flow outcomes in a series of percutaneously placed external jugular (EJ), LIJ and RIJ HD catheters. Methods Using a prospectively collected database, we identified 46 hemodialysis patients who received a tunneled catheter during a 4-year period. Blood flow outcomes of RIJ, LIJ, and EJ catheters that were date-matched over the study period were compared. Using ANOVA, the blood flow outcomes of the 3 tunneled catheter techniques at 30-d and 90-d were compared. Results The 90-d blood flow outcomes of the 3 groups did not differ significantly. The 30-d blood flow was found to be 348.5± 56.62, 341± 22.42, and 365.7± 71.76 mL/min for RIJ, LIJ, and EJ respectively (PConclusions EJ blood flow outcomes at 30-d and 90-d were comparable to both LIJ and RIJ historic data. Further prospective investigation is required to define the role of EJ CVC placement as another potential long-term access modality.

Even though many positive changes were ushered in by the KDOQI guidelines and the Fistula First Breakthrough Initiative, tunneled hemodialysis catheters remain an essential piece of the dialysis access puzzle. Their use is, however, attended by a multitude of complications and morbidity of which the general nephrologist must be aware. The purpose of this article is to review for the general nephrologist the infectious and non-infectious problems that often complicate the use of hemodialysis catheters.

Once thought to be a minor player in hemodialysis (HD) access dysfunction relative to outflow stenosis, inflow stenosis has recently come to be viewed as a major cause of access failure. Indeed, recent literature has shown that up to 40% of all accesses referred for dysfunction have an inflow lesion. Imaging of the inflow segment has been traditionally performed by interventional nephrologists via retrograde occlusive arteriography (ROA). Recent advances in our understanding of ROA have cast the technique in a negative light, with the possibility of vascular complications and poor diagnostic yield coming to the fore. Using a prospectively collected, vascular access database, we identified 18 consecutive patients who received imaging of inflow lesions by ROA and direct arteriogram (DA). The mean percent luminal stenoses were found to be 59.89 ± 24 and 79.06 ± 17.8 (p = 0.009) for the ROA vs. DA groups, respectively. Using multiple regression analysis, DA was found to be associated with detecting higher degree of luminal stenosis (β = 19.17, 95% CI 6.28-32.05, p = 0.006). This small case series provides evidence on the theoretical concern that ROA does not adequately evaluate inflow lesions. We may conclude that by relying solely on ROA, interventional nephrologists may be failing to detect a subset of hemodynamically significant inflow lesions.

Purpose Endovascular stents have recently been shown to extend access patency in thrombosed and stenotic arteriovenous grafts. Given this improved patency, stent placement has outpaced balloon angioplasty in hemodialysis (HD) access interventions. However, concern remains over localized corrosion and increased neointimal hyperplasia of overlapping stents in the access circuit and whether this promotes premature stent failure. Methods This is a retrospective analysis of HD patients referred for access dysfunction during a 2-yr period. Using a prospectively collected, vascular access database, we identified 76 patients seen for follow-up angiography due to access dysfunction after stent placement. We compared the outcomes of overlapping vs. non-overlapping stents in measured primary assisted patency and mean percent luminal diameter as a marker of lesion severity. Results The two groups did not differ significantly in demographics or comorbid conditions. Only gender had a significant discrepancy between the two groups, with 65.5% vs. 42.9% male (p=0.01) in the overlapping vs. non-overlapping stent groups, respectively. The mean percent luminal stenosis was found to be 83.7 ± 17.3 and 85.5 ± 12.6 (p=0.55) for the overlapping vs. non-overlapping stent groups, respectively. For overlapping and non-overlapping stents, 30-day primary patency was 94% and 89%, respectively, 60-day primary patency was 77% and 63%, respectively, and 90-day primary patency was 68% and 50%, respectively. Using multiple regression analysis, no risk factors were identified to be associated with the severity of luminal stenosis. No identifiable risk factors were found to be associated with improved primary patency. In particular, overlapping vs. non-overlapping stents were not identified as a statistically significant factor influencing primary (assisted) patency (hazards ratio 0.60; 95% cI 0.34 to 1.06; p>0.05). Conclusions This study provides evidence that the theoretical concern of metal on metal corrosion and increased neointimal hyperplasia that can be seen with overlapping stents does not play a significant clinical role.

A new educational document titled "Coding Procedures in Interventional Nephrology 2010" has been published by ASDIN for 2010. The purpose of this communication is to present a review of these new regulations issued by CMS to take effect January 1, 2010, and how they will affect the coding of interventional procedures used in vascular access maintenance.

Arteriovenous fistulae (AVF) outcomes in the United States continue to fall short of expectations and continue to compare disfavorably to European AVF outcomes. This study presents the early experience of nephrologist created AVF outcomes in the U.S. hemodialysis population. A retrospective analysis of a prospectively collected vascular access database was performed. All patients who were referred for vascular access placement over a 1-year period were eligible for inclusion. One hundred five (n = 105) patients were initially included in the database. An AVF was placed in 100% of patients referred for vascular access. Two complications were identified (one steal syndrome and one infection) for a rate of 1.9%. The patient demographics included 38.7% female, age 63.6 + or - 14.8, 50.0% diabetic, 66.0% hypertensive, with 65.1% of patients in stage 5 chronic kidney disease at the time of AVF placement. Average target artery diameter was 4.09 + or - 1.16 mm while average target vein diameter was 3.66 + or - 1.20. Twenty-one AVF were placed in the forearm (19.8%) with the remainder being placed in the upper arm vessels. Eighteen patients (18.56%) failed to mature at 6 weeks. Sixty-four patients (65.98%) required revision or intervention of their AVF between 12 weeks postoperatively and the endpoint of the study. Eighty patients (84.21%) had patent AVF at an average follow-up of 286.2 + or - 98.14 days. No identifiable risk factors among those listed above were associated with a significant impact on AVF outcomes. AVF outcomes that compare favorably to those of Europe can be achieved by U.S. interventional nephrologists. Furthermore, the dictum that distal is better needs to be re-examined if the United States hopes to achieve the goal of 66% AVF prevalence.

A case is presented and a novel technique is described by which an endovascular stent is deployed in the venous outflow system of an arteriovenous fistula without the traditional exchange to a larger diameter introducer sheath.

Arterial stenoses in patients with arteriovenous dialysis access can create a variety of problems including access dysfunction, thrombosis, and hand ischemia. While percutaneous balloon angioplasty is largely successful in the management of arterial stenoses, elastic recoil can present a real predicament to this treatment. In this report, we present two cases of arterial stenosis that demonstrated elastic recoil after angioplasty and required endovascular stent insertion. Both cases were treated successfully without any complications on an outpatient basis. This report describes arterial stent placement in patients with arteriovenous access and discusses anticoagulation considerations in such cases.

Despite aggressive efforts to increase autogenous fistula prevalence primarily from recommendations by the NKF and the Fistula First National Vascular Access Improvement Initiative, catheters remain an essential access modality for a large percentage of the hemodialysis population. Tunneled dialysis catheters or chronic catheters are associated with a multitude of complications including infections, stenosis, thrombosis, and increased morbidity and mortality even after adjustment for potential confounding variables. Also, given the blood flow rates of catheters, dialysis adequacy is compromised as compared with arteriovenous fistulae and arteriovenous grafts. This review endeavors to provide an update on catheter outcomes in the Fistula First and Kidney Disease Outcomes Quality Initiative era in relation to the increasing fistula prevalence and decline in graft placements. The conflicting view of whether catheters are increasing concurrently with the increase in fistula prevalence is discussed. The management of tunneled dialysis catheter-related complications is considered with a review of the most recent data. Future research strategies and innovations in catheter design are also addressed. This review provides a comprehensive update of tunneled hemodialysis catheters, their necessity and pitfalls, and novel directions for future investigation.

The purpose of this review is to explore the pathophysiology, epidemiology, and interventional treatment of central vein stenosis (CVS) that may result from central vein catheter (CVC) placement. The precise mechanism of CVC-associated CVS remains largely undefined, though anatomic considerations appear to play a prominent pathologic role. The impact of CVC-associated CVS on arteriovenous fistula outcomes is reviewed. The percutaneous treatment of CVS, observation, angioplasty, or angioplasty with stent placement is reviewed, along with potential surgical treatment options. As the treatment outcomes of CVC-associated CVS have been disappointing, catheter avoidance remains the best strategy.