Catheter-related mortality among ESRD patients

Self-healing and cell-free vascular grafts

We developed an innovative self-healing tissue engineering vessel (SH-TEV) that heals fast after repeated needle punctures, while maintaining artery like mechanical strength and toughness even under wet conditions. The SH-TEV is designed as a bilayer tube engineered by electrospinning an autonomous self-healing polyurethane, PU-DAA, around a tube of a native biomaterial, small intestinal submucosa (SIS), that can be functionalized with biomolecules to recruit host cells and promote endothelialization. The self-healing PU-DAA was designed to incorporate multi-strength H-bonds and reversible hydrazone bonds and exhibited high strength (3.95 ± 0.16 MPa), toughness (23.01 ± 2.37 MJ/m3), and fast autonomous self-healing (86.44 ± 6.65 % after 12 h) under physiological conditions. The self-healing layer supported attachment, spreading and proliferation of fibroblasts, indicating biocompatibility. When SH-TEVs were implanted as interpositional grafts into the rat aorta for 4 weeks, they remained patent without any thrombosis (100 % animal survival and 100 % graft patency), were endothelialized and developed a smooth muscle cell containing vascular wall. In addition, they showed excellent self-healing ability following needle puncture (hemostatic time <40 s) immediately after implantation and four weeks later. Collectively, these results demonstrate the potential of SH-TEVs as vascular access conduits for hemodialysis applications.

Challenges surrounding hemodialysis initiation faced by undocumented immigrants

OBJECTIVE

Hemodialysis (HD) care in the United States for undocumented immigrants remains a challenging issue. The objective of this study is to evaluate the timeliness of nephrology and vascular surgery care provided to undocumented immigrants with end-stage renal disease compared with their documented counterparts. Additionally, we evaluate catheter-related complications in undocumented patients on HD.

METHODS

A retrospective chart analysis was performed of patients undergoing first-time arteriovenous access (AVA) creation at a single center from 2012 to 2018 to compare outcomes between documented and undocumented patients. Additionally, within the undocumented group, we compared outcomes between patients dependent on a central venous catheter (CVC group) to patients with a CVC and transition to an AVA (CAV group). The primary outcomes were time to initial evaluation by nephrology, vascular surgery, and AVA creation, as well as complications associated with long-term CVC use within the undocumented patients.

RESULTS

A total of 290 patients underwent first-time AVA creation (62 undocumented; 228 documented). Undocumented patients were younger at the time of surgery and, more commonly, Hispanic. Undocumented patients were more likely to receive their first nephrology evaluation upon HD initiation (59.7% vs 25.4%; P < .001). Regarding vascular access surgery initial evaluation for AVA creation, undocumented patients were more likely to be evaluated after initiating HD (74.2% vs 38.6%; P < .001). After being evaluated for AVA creation, there was no difference in time from vascular surgery evaluation to surgery (25 days vs 20 days; P = .95) or from surgery to AVA maturation (77 days vs 57 days; P = .31). As a result, undocumented patients were more likely to start dialysis with a CVC (90.3% vs 66.7%; P = .0004). Undocumented patients in the CVC group were more likely to experience catheter-related complications compared with their undocumented counterparts in the CAV group (CVC 72.5% vs CAV 45.9%; P = .032). The CAV patients were found to have an earlier occurrence of their first catheter-related complications, driving an earlier evaluation for AVA creation and subsequent CVC removal.

CONCLUSIONS

Due to limited access to health care, undocumented immigrants with end-stage renal disease had a significant delay in evaluation by nephrologists and vascular access surgeons for AVA creation with a higher use of CVC for dialysis initiation. CVC-related complications are highly frequent and avoidable in undocumented patients with an earlier referral for creation of appropriate AVA.

Management of thrombosed or failed dialysis access

Hemodialysis (HD) access for patients with end-stage renal disease is a steadily increasing necessity, and maintaining patency of native or synthetic fistulas can be challenging. The main physiologic changes of an HD access that cause it to fail are inflow or outflow vessel stenosis or access thrombosis. These are propagated by factors intrinsic to end-stage renal disease, altered hemodynamics from a fistula, and typically further exacerbated by associated comorbidities. Diagnosis of fistula dysfunction can be made with a combination of history, physical examination, HD dynamic measurements, laboratory findings, and invasive or noninvasive imaging. Stenoses can be managed with endovascular interventions, including angioplasty with or without stenting, or open operations. Thrombosis of HD access, which is most often a result of an underlying stenosis, can be managed similarly with either endovascular or surgical thrombectomy with adjunctive treatment. Our goal was to review the pathophysiology of the most common forms of fistula failure, diagnosis, and endovascular and surgical options for flow restoration.

Accuracy of physical examination versus Doppler ultrasonography for determining maturity in postoperative arteriovenous fistula formation

BACKGROUND

Differentiating between arteriovenous fistula (AVF) maturation and failure can help determine which AVF will undergo successful canulation and which ones will require immediate rescue.

METHODS

A prospective observational study was conducted at Vajira Hospital in Bangkok, Thailand, between October 2020-November 2022. A single vascular surgeon performed a physical examination on patients with chronic kidney disease undergoing AVF placement, and a radiologist conducted Doppler ultrasonography during the second and sixth postoperative weeks. Dialysis nurses determined AVF maturity by performing cannulation. The study compared the accuracy of physical examination and Doppler ultrasonography. A model was developed to predict the success of AVF use.

RESULTS

Out Of the 125 recruited patients, 81% demonstrate unassisted maturation of their AVF. The male sex and brachiocephalic type are associated with AVF maturation. The physical examination findings of palpable thrill and the absence of a strong pulse at the 6th week show an area under the receiver operating curve (AUC) value of 0.79. Similarly, arterial end-diastolic velocity on ultrasonography at the 6th week also demonstrates a comparable predictive value with an AUC of 0.82 (p = 0.697). Meanwhile, the model that combined end-diastolic velocity and venous volume flow yields the best results for predicting AVF maturation, with an AUC of 0.92. These models provide more accurate predictions compared to physical examination alone (AUC: 0.92 vs. 0.79; p < 0.01).

CONCLUSION

Although a prudent physician predicts AVF maturation through a thorough physical examination, Doppler ultrasonography is preferred in anticipating the success of postoperative AVF placement.

VasQ U.S. pivotal study demonstrates the safety and effectiveness of an external vascular support for arteriovenous fistula creation

OBJECTIVE

Arteriovenous fistula (AVF) creation is a commonly performed vascular operation that reports 6-month functional success rates as low as 50%. Recently, a nitinol external vascular support device, VasQ, has shown potential in studies outside the United States (U.S.) to improve AVF outcomes when implanted at creation. Here, the pivotal study results of this novel technology in treating patients in the U.S. are described.

METHODS

VasQ was implanted in 144 patients at 16 centers across the U.S. who were referred for creation of a new AVF and consented for enrollment in a 2-year, prospective, multicenter, single-arm, open-label study. Brachiocephalic (n = 129) and radiocephalic (n = 15) AVFs were analyzed. The primary endpoint was primary patency at 6 months compared against a performance goal of 55% derived from a systematic literature search. Safety endpoints included device-related events, ischemic steal, infection, aneurysm, and seroma at up to 6 months. Minimum arterial size was 2.0 mm; target veins were required to measure 2.5 to 6 mm. Key exclusion criteria were patients <18 or >80 years, those with known ipsilateral central venous occlusion, target cannulation zone venous depth greater than 8 mm, and New York Heart Association class 3 or 4.

RESULTS

Patients were 61% male, 53% White, 35% African American, and 14% Hispanic. Mean age was 60 years, and median body mass index was 30.4. Of the patients, 69% were diabetic, 66% were on dialysis at the time of creation, and 70% had a prior access surgery. At 6 months, steal was observed in 2.1%, infection in 0.7%, and no aneurysms or seromas were seen. Primary patency at 6 months was 66% (P < .021 vs performance goal). Physiological maturation was achieved in 92.4% of patients. Successful two-needle cannulation for patients that entered the study on dialysis was achieved in 88% of VasQ AVFs at a median of 56 days. Pre-dialysis patients who initiated dialysis during the study achieved two-needle cannulation in 81.6% VasQ AVFs. Interventions were required at a rate of 1.07 per patient year over the entire study period. Two-year cumulative patency was 76.6% (95% confidence interval, 67.9%-83.4%) with no statistical difference between patients requiring interventions and those that did not. No patency differences were observed between brachiocephalic and radiocephalic AVFs.

CONCLUSIONS

The U.S. pivotal study results demonstrated improved AVF outcomes and an excellent safety profile with VasQ use relative to traditional AVFs. Under the conditions of this trial, VasQ shows great promise in expeditiously and efficiently enhancing AVF functional success.

Management of concomitant central venous disease

Symptomatic central venous disease (CVD) is a significant common problem in patients with end-stage renal disease given its adverse impact on hemodialysis (HD) vascular access (VA). The current mainstay management is percutaneous transluminal angioplasty (PTA) with or without stenting which is typically reserved for unsatisfactory angioplasty or more challenging lesions. Despite factors such as target vein diameters and lengths and vessel tortuosity that may determine the choice of bare-metal versus covered stents (CS), current scientific literature is pointing out the superiority of the latter one. Alternative management options such as hemodialysis reliable outflow (HeRO) graft showed favorable results in terms of high patency rates and fewer infections, however, complications such as a steal syndrome and, to a lesser extent, graft migration and separation are major concerns. The surgical reconstruction approaches such as bypass, patch venoplasty, or chest wall arteriovenous graft with or without endovascular interventions as a hybrid procedure are still viable options and may be considered. However, further long-term investigations are needed to highlight the comparative outcomes of these approaches. Open surgery might be an alternative before proceeding to more unfavorable approaches such as lower extremity vascular access (LEVA). The appropriate therapy should be selected based upon a patient-centered interdisciplinary discussion utilizing the locally available expertise in the area of VA creation and maintenance.

Revision of Aneurysmal Arteriovenous Access with Immediate Use Graft Is Safe and Avoids Prolonged Use of Tunneled Hemodialysis Catheters

INTRODUCTION

Aneurysmal AVF can pose a difficult treatment dilemma for the vascular surgeon. Prolonged tunneled dialysis catheters (TDC) in patients requiring long-term dialysis are associated with significantly increased mortality compared to arteriovenous fistulas (AVF). We aimed to elucidate the outcomes of aneurysmal AV access revision with aneurysm resection and Artegraft® (LeMaitre, New Brunswick, NJ) Collage Vascular Graft placement to avoid prolonged use of TDCs.

METHODS

We reviewed all patients with aneurysmal AV access in which the access was revised with aneurysm resection and jump graft placement at a single institution from 2018 to 2021. Outcomes were time to cannulation, reintervention rates, time to reintervention and patency (primary, primary assisted and secondary). Patency rates were estimated with Kaplan-Meier Survival analysis.

RESULTS

A total of 51 revised aneurysmal AV access in 51 patients were studied, of which 23.5% (n=12) had perioperative TDC placement. Three patients were done for emergent bleeding. The cohort was 62.8% male (n=32) with a median age of 58 years (IQR: 49-67). Most patients had brachiocephalic AVF (n=37 [72.6%]). Median follow up time was 280 days. Median time to cannulation was 2 days. Time to cannulation was significantly longer in patients with perioperative TDC as compared with those without TDC (24 days vs 2 days, P<0.001). Reintervention was required in 41.2% of patients (n=21), at median time of 47 days. At 30, 90, 180, and 365 days, primary patency rates were 84.3%, 78.3%, 66.6%, and 54.9%; primary assisted patency rates were 94.1%, 88.1%, 79.4%, and 79.4% and secondary patency rates were 100%, 97.8%, 91.6% and 91.6% respectively.

CONCLUSIONS

Revision of aneurysmal AV access (urgent or elective) with Artegraft as jump graft is safe, with acceptable short and mid-term patency results. This allows dialysis patients to continue to have a functional access, decreasing the need for a tunneled catheter and reducing the associated risk of sepsis and increased mortality. This should be considered for all patients with aneurysmal, dysfunctional fistulas to maintain AV access and avoid TDC placement.

Drug-eluting balloon (DEB) versus plain old balloon angioplasty (POBA) in the treatment of failing dialysis access: A prospective randomized trial

Objective

To compare the efficacy of angioplasty using drug-eluting balloons (DEB) compared with plain old balloon angioplasty (POBA) to reduce the rate of restenosis.

Methods

This prospective, single-centre, single-blinded, 1:1 randomized, clinical trial enrolled patients that had primary or restenotic lesions in native upper extremity arteriovenous (AV) fistulas or at the graft-venous anastomosis. Patients were randomized to angioplasty with a POBA or a DEB. The primary effectiveness endpoints were freedom from target lesion revascularization (TLR) and functional status of access circuit at 12 months.

Results

A total of 42 (28 male, 14 female; age range, 42–83 years) patients were enrolled. Patients were followed for 12 months. No significant differences were detected between the POBA and DEB groups regarding total number of TLR procedures (31 versus 36, respectively), freedom from TLR (3 versus 4, respectively) and functional status of the access circuit at 12 months (14 of 20 patients [70%] versus 17 of 22 patients [77%], respectively).

Conclusion

This clinical trial did not demonstrate any significant differences between DEB angioplasty and standard balloon angioplasty when treating dysfunctional haemodialysis access.

Sterile inflammation in the pathogenesis of maturation failure of arteriovenous fistula

Chronic kidney disease is a widespread terminal illness that afflicts millions of people across the world. Hemodialysis is the predominant therapeutic management strategy for kidney failure and involves the external filtration of metabolic waste within the circulation. This process requires an arteriovenous fistula (AVF) for vascular access. However, AVF maturation failures are significant obstacles in establishing long-term vascular access for hemodialysis. Appropriate stimulation, activation, and proliferation of smooth muscle cells, proper endothelial cell orientation, adequate structural changes in the ECM, and the release of anti-inflammatory markers are associated with maturation. AVFs often fail to mature due to inadequate tissue repair and remodeling, leading to neointimal hyperplasia lesions. The transdifferentiation of myofibroblasts and sterile inflammation are possibly involved in AVF maturation failures; however, limited data is available in this regard. The present article critically reviews the interplay of various damage-associated molecular patterns (DAMPs) and the downstream sterile inflammatory signaling with a focus on the NLRP3 inflammasome. Improved knowledge concerning AVF maturation pathways can be unveiled by investigating the novel DAMPs and the mediators of sterile inflammation in vascular remodeling that would open improved therapeutic opportunities in the management of AVF maturation failures and its associated complications.

Drug-Coated Balloons for Dysfunctional Dialysis Arteriovenous Fistulas

BACKGROUND

Standard percutaneous transluminal angioplasty is the current recommended treatment for dysfunctional hemodialysis fistulas, yet long-term outcomes of this treatment are poor. Drug-coated balloons delivering the antirestenotic agent paclitaxel may improve outcomes.

METHODS

In this prospective, single-blinded, 1:1 randomized trial, we enrolled 330 participants at 29 international sites. Patients with new or restenotic lesions in native upper-extremity arteriovenous fistulas were eligible for participation. After successful high-pressure percutaneous transluminal angioplasty, participants were randomly assigned to receive treatment with a drug-coated balloon or a standard balloon. The primary effectiveness end point was target-lesion primary patency, defined as freedom from clinically driven target-lesion revascularization or access-circuit thrombosis during the 6 months after the index procedure. The primary safety end point, serious adverse events involving the arteriovenous access circuit within 30 days, was assessed in a noninferiority analysis (margin of noninferiority, 7.5 percentage points). The primary analyses included all participants with available end-point data. Additional sensitivity analyses were performed to assess the effect of missing data.

RESULTS

A total of 330 participants underwent randomization; 170 were assigned to receive treatment with a drug-coated balloon, and 160 were assigned to receive treatment with a standard balloon. During the 6 months after the index procedure, target-lesion primary patency was maintained more often in participants who had been treated with a drug-coated balloon than in those who had been treated with a standard balloon (82.2% [125 of 152] vs. 59.5% [88 of 148]; difference in risk, 22.8 percentage points; 95% confidence interval [CI], 12.8 to 32.8; P<0.001). Drug-coated balloons were noninferior to standard balloons with respect to the primary safety end point (4.2% [7 of 166] and 4.4% [7 of 158], respectively; difference in risk, -0.2 percentage points; 95% CI, -5.5 to 5.0; P = 0.002 for noninferiority). Sensitivity analyses confirmed the results of the primary analyses.

CONCLUSIONS

Drug-coated balloon angioplasty was superior to standard angioplasty for the treatment of stenotic lesions in dysfunctional hemodialysis arteriovenous fistulas during the 6 months after the procedure and was noninferior with respect to access circuit-related serious adverse events within 30 days. (Funded by Medtronic; IN.PACT AV Access Study ClinicalTrials.gov number, NCT03041467.).

Association of Dysfunction of Vascular Access for Hemodialysis With Major Adverse Cardiovascular Events - A Group-Based Trajectory Model Analysis

BACKGROUND

An unconventional risk factor, "dysfunction of hemodialysis vascular access", was demonstrated to be associated with subsequent major adverse cardiovascular events (MACE) in our previous study. However, applying this suggestion in a clinical scenario may be not intuitive. A group-based trajectory model was applied to further recognize those patients with the highest risks for MACE.

METHODS AND RESULTS

In a cohort of patients who received hemodialysis from 2001 to 2010, we identified 9,711 cases that developed MACE in the stage of stable maintenance dialysis, and 19,422 randomly selected controls matched to cases on age, gender and duration of dialysis. Events of vascular access dysfunction in the 6-month period before MACE for cases and index dates for controls were evaluated. By group-based trajectory modeling, patients according to their counts of vascular access dysfunction in each month over the 6-month period prior to MACE or index dates were categorized. There were 26,744 patients in group 1 (no dysfunction), 650 in group 2 (escalating dysfunction) and 1,739 in group 3 (persistent dysfunction). Logistic regression analysis indicated that patients in group 3 had the highest chance of subsequent MACE (odds ratio 2.47, in comparison with group 1) after controlling for all the available potential confounders.

CONCLUSIONS

Uninterrupted clusters of vascular access dysfunction are associated with a higher risk of subsequent MACE.

Causes of the delay in creating permanent vascular access in hemodialysis patients

Majority of the chronic kidney disease (CKD) patients undergo hemodialysis (HD) with central venous catheter which has multiple complications. This study aims to identify the physicians' perspectives regarding the reasons of delayed arteriovenous fistula (AVF) creation in the Kingdom of Saudi Arabia to improve the quality of CKD patients' care and prognosis and prevent complications. A cross-sectional descriptive study was conducted on KSA nephrologists using a questionnaire which includes factors associated with delay in AVF creation, which were categorized into patient, physician, and hospital factors. The optimal timing of starting dialysis was also assessed. In a total of 212 participants, 131 (61.8%) were of consultant level, with the largest numbers being from the Central region (52.4%). The most important patient factors associated with delay in AVF creation were denial of kidney disease or the need of AVF (76.4%), dialysis fears and practical concern (75.9%), and patient refusal (73.1%). The most important physician and hospital factors were insufficient conduction of predialysis care and education (63.7%) and late referral to a nephrologist (56.6%). Participants would create AVF when the patient reaches Stage 4 CKD (69.3%) or Stage 5 (27.4%), and 88.7% of the participants would do so 3-6 months before the anticipated start of HD. Over two-thirds of the participants (68.4%) chose patient as the main factor contributing to the delay of permanent vascular access. A validated approach to patient selection, patient-centered predialysis care, and referral to vascular access creation that could be applied on different types of patients in different regions is required.

Risk and complications of venous thromboembolism in dialysis patients

Background

Contemporary data on venous thromboembolism (VTE) risk in dialysis patients are limited. Our objective was to determine the risk and complications of VTE among incident maintenance dialysis patients.

Methods

We performed a retrospective cohort study using administrative databases. We included adult incident dialysis patients from 2004 to 2010 (n = 13 315). Dialysis patients were age- and sex-matched to individuals of the general population using a 1:4 ratio (n = 53 260). We determined the 3-year cumulative incidence and incidence rate (IR) of VTE, pulmonary embolism (PE) and deep venous thrombosis (DVT). We examined outcomes of bleeding and all-cause mortality following a VTE event among matched dialysis patients who did and did not experience a VTE. We used Cox proportional hazards regression models, stratified on matched sets, to calculate the hazard ratios (HRs) for all outcomes of interest.

Results

VTE occurred in 1114 (8.4%) dialysis patients compared with 1233 (2.3%) individuals in the general population {IR 37.1 versus 8.1 per 1000 person-years; HR 4.5 [95% confidence interval (CI) 4.1-4.9]; adjusted HR 2.9 (95% CI 2.6-3.4)}. Both components of VTE [PE and DVT; adjusted HR 4.0 (95% CI 2.9-5.6) and HR 2.8 (95% CI 2.4-3.2), respectively] occurred more frequently in dialysis patients. Compared with dialysis patients without a VTE, those with a VTE had a higher risk of bleeding [adjusted HR 2.0 (95% CI 1.3-2.9)] and all-cause mortality [adjusted HR 2.4 (95% CI 2.0-2.8)].

Conclusions

VTE is common in dialysis patients and confers a high risk of major bleeding and all-cause mortality. Thromboprophylaxis and VTE treatment studies in dialysis patients are needed.

A demonstration project on the impact of safety culture on infection control practices in hemodialysis

BACKGROUND

Infections among hemodialysis patients continues to be major causes of morbidity and mortality despite advances in the science of infection prevention. Many infections are potentially preventable, yet research suggests that evidence-based interventions are not uniformly practiced in dialysis settings. The purpose of the project was to reduce the risk of infection among hemodialysis patients in an outpatient dialysis clinic in upstate New York through the development of an enhanced patient safety culture.

METHODS

A survey was used to assess the safety culture of a large outpatient dialysis program. A Comprehensive Unit-based Safety Program was instituted to enhance infection prevention practices. Evidence-based checklists and audit tools were used to track staff adherence to protocols.

RESULTS

Scores on the survey were strongly correlated with bloodstream infection rates. Adherence to infection control standards improved when the End Stage Renal Disease Safety Program was implemented, with audits improving from 27%-82% of procedures performed correctly. Bloodstream infection rates decreased from 2.33-1.07 events per 100 patient months, and the standardized infection ratios decreased from 1.960-0.985 in the 12-months after implementation.

CONCLUSIONS

The Comprehensive Unit-based Safety Program model and implementation of the safety program may be effective in improving the culture of safety and adherence to evidence-based practices in hemodialysis. Enhanced patient safety culture is correlated with improved patient outcomes.

Early cannulation of the Hemodialysis Reliable Outflow graft

OBJECTIVE

In complex dialysis patients, central venous stenosis may preclude additional upper extremity access options. The Hemodialysis Reliable Outflow graft (Merit Medical Systems, Inc.) can bypass this stenosis providing patients with an additional upper extremity long-term access option. We report our experience with early-cannulation Hemodialysis Reliable Outflow grafts and compare them to traditional Hemodialysis Reliable Outflow grafts.

METHODS

We retrospectively reviewed all patients undergoing Hemodialysis Reliable Outflow graft placement from 1 January 2013 through 15 August 2017 at our institution and compared those undergoing placement of traditional Hemodialysis Reliable Outflow grafts and simultaneous tunneled dialysis catheter insertion to those undergoing Hemodialysis Reliable Outflow graft placement using an early-cannulation Hemodialysis Reliable Outflow graft without a tunneled dialysis catheter.

RESULTS

A total of 88 patients had 98 Hemodialysis Reliable Outflow grafts inserted throughout this time period. Of these, 61 (62%) were early-cannulation Hemodialysis Reliable Outflow grafts, while 37 (38%) were traditional Hemodialysis Reliable Outflow grafts. Primary, primary-assisted, and secondary patency rates at 1 year were higher for the traditional Hemodialysis Reliable Outflow graft cohort (53.1% vs 25.2%, p < 0.01; 70.1% vs 30.5%, p < 0.01; and 80.4% vs 55.4%, p = 0.07, respectively). There was no difference in the rate of postoperative hematoma, seroma, pseudoaneurysm formation, steal syndrome, or overall graft thrombosis between the two cohorts. Early-cannulation Hemodialysis Reliable Outflow grafts required earlier reintervention for thrombosis and earlier reintervention for any cause when compared to traditional Hemodialysis Reliable Outflow grafts (146 ± 184 days vs 417 ± 272 days, p < 0.01, and 123 ± 169 days vs 401 ± 311 days, p < 0.01, respectively).

CONCLUSION

In complex dialysis patients, early-cannulation Hemodialysis Reliable Outflow grafts have significantly lower 1-year primary and primary-assisted patency rates and require earlier reintervention to maintain this patency compared to traditional Hemodialysis Reliable Outflow grafts.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A randomized trial of vonapanitase (PATENCY-1) to promote radiocephalic fistula patency and use for hemodialysis

OBJECTIVE

Arteriovenous fistulas created in patients with chronic kidney disease often lose patency and fail to become usable. This prospective trial evaluated the efficacy of vonapanitase, a recombinant human elastase, in promoting radiocephalic fistula patency and use for hemodialysis.

METHODS

PATENCY-1 was a double-blind, placebo-controlled trial that enrolled 349 patients on or approaching hemodialysis and being evaluated for radiocephalic arteriovenous fistula creation. Of these, 313 were randomized and 311 treated. Patients were assigned to vonapanitase (n = 210) or placebo (n = 103). The study drug solution was applied topically to the artery and vein for 10 minutes immediately after fistula creation. The primary and secondary end points were primary patency (time to first thrombosis or corrective procedure) and secondary patency (time to abandonment). Tertiary end points included use of the fistula for hemodialysis, fistula maturation by ultrasound, and procedure rates.

RESULTS

The Kaplan-Meier estimates of 12-month primary patency were 42% (95% confidence interval [CI], 35-49) and 31% (95% CI, 21-42) for vonapanitase and placebo (P = .25). The Kaplan-Meier estimates of 12-month secondary patency were 74% (95% CI, 68-80) and 61% (95% CI, 51-71) for vonapanitase and placebo (P = .048). The proportions of vonapanitase and placebo patients were 39% and 25% (P = .035) with unassisted use for hemodialysis and 64% and 44% (P = .006) with unassisted plus assisted use.

CONCLUSIONS

Vonapanitase treatment did not significantly improve primary patency but was associated with increased secondary patency and use for hemodialysis. Further research is needed to evaluate these end points.

Outcomes of tunneled internal jugular venous catheters for chronic haemodialysis at the University College Hospital, Ibadan, Nigeria

Introduction

vascular access is an important aspect of haemodialysis treatments and determinant of patient outcomes. Arteriovenous (AV) fistula has been described as the preferred haemodialysis vascular access for patients on chronic dialysis. There continues to be a challenge with the creation of AV fistula, due to shortage of vascular surgeons skilled in the AV fistula creation particularly in source limited setting. We described the outcomes of the tunneled internal jugular venous catheters amongst our patients at the University College Hospital (UCH) Ibadan.

Methods

a retrospective study of patients on maintenance haemodialysis at the UCH, Ibadan, we reviewed the records of all patients on chronic dialysis over a period of 5 years. Information obtained include demographics, types and aetiology of renal failure, types of vascular access, observed complications and outcomes.

Results

a total number of 147 catheters were inserted during the period under review, 94 were males while 53 were females. The age range was 18-85 years while the mean age was 46.3 ± 17.2 years. The range and mean duration for Tunneled Dialysis Catheter (TDC) carriage were (30 - 1,440) and 220±185 days respectively. The observed immediate complications of TDCs were failed first attempt 7(4.7%), reactionary haemorrhage 5(3.4%), arrhythmia 3(2.0%), haemothorax 2(1.4%) while death during catheter placement was recorded in 2(1.4%) cases. Catheter related infection was the commonest long-term complications and occurred in 15 cases (10.1%), while being diabetic increased the risk of developing catheter related complications. One tenth of our patients with End Stage Renal Disease on TDC had kidney transplantation while catheter related mortality was 16.3%.

Conclusion

internal jugular tunneled dialysis catheters despite its shortcomings, has been a safe procedure with good outcomes among our patients on maintenance haemodialysis.

Flow Rates at Thirty Days after Construction of Radiocephalic Arteriovenous Fistula Predict Hemodialysis Function

BACKGROUND

Construction of radiocephalic arteriovenous fistula (RC-AVF) results in successful hemodialysis (HD) in approximately 40% of end-stage renal disease patients. We investigated whether RC-AVF flow measured by ultrasound 30 days postoperative predicted successful HD.

METHODS

In this prospective study, color Doppler ultrasound was used to measure cephalic vein outflow volume at 3 forearm sites at 1 and 3 months postoperatively.

RESULTS

Of 45 consecutive patients screened for feasibility of RC-AVF by physical examination and US arterial and vein mapping, 41 were considered suitable for construction of RC-AVF. Mean age was 70 (60-78) years. Of the 41 patients who had a forearm RC-AVF, 25 (61%) proceeded to successful AVF dialysis, 4 (10%) had HD via central venous catheter, and 12 (29%) ceased function within the first 30 days postoperatively. The mean flow at 30 days for patent fistulas was 629 ± 305 ml/min and by the third month had increased to 663 ± 367 mL/min. At 1 month, 8/29 (27.6%) patients had a flow rate <400 mL/min. Two (25%) of these clotted, 2 of 3 with closed revisions went on to HD, and 1 died. Of the 21 patients with a flow rate ≥400 mL/min, 19 (90%) functioned for HD, and 2 (10%) AVF occluded before 1 year, resulting in 17 functioning at 1 year (81% 1-year patency). Sixty-two percent of the low-flow fistulas had successful patency within 1 year.

CONCLUSIONS

An RC-AVF flow rate of ≥400 mL/min in the first month predicted more successful HD than low flow (<400 mL/min) (81% vs. 62%). Without intervention, low flow rates do not improve significantly and maturation is unlikely. We recommend imaging for all patients at 30 days to identify and promptly correct stenosis in those with low flow rates.

Central venous catheters for chronic hemodialysis: Is "last choice" never the "right choice"?

Since the publication of the first vascular access clinical practice guidelines in 1997, the global nephrology community has dedicated significant time and resources toward increasing the prevalence of arteriovenous fistulas and decreasing the prevalence of central venous catheters for hemodialysis. These efforts have been bolstered by observational studies showing an association between catheter use and increased patient morbidity and mortality. To date, however, no randomized comparisons of the outcomes of different forms of vascular access have been conducted. There is mounting evidence that much of the difference in patient outcomes may be explained by patient factors, rather than choice of vascular access. Some have called into question the appropriateness of fistula creation for certain patient populations, such as those with limited life expectancy and those at high risk of fistula-related complications. In this review, we explore the extent to which catheters and fistulas exhibit the characteristics of the "ideal" vascular access and highlight the significant knowledge gaps that exist in the current literature. Further studies, ideally randomized comparisons of different forms of vascular access, are required to better inform shared decision making.

Bilateral Arteriovenous Shunts as a Method for Evaluating Tissue-Engineered Vascular Grafts in Large Animal Models

There remains a need for large animal models to evaluate tissue-engineered vascular grafts (TEVGs) under arterial pressure to provide preclinical data for future potential human clinical trials. We present a comprehensive method for the interrogation of TEVGs, using an ovine bilateral arteriovenous (AV) shunt implantation model. Our results demonstrate that this method can be performed safely without complications, specifically acute heart failure, steal syndrome, and hypoxic brain injury, and it is a viable experimental paradigm. Our method allows for a non-invasive evaluation of TEVGs in terms of graft flow, graft diameter, and graft patency, while also allowing for graft needle puncture under ultrasound guidance. In addition, traditional pathological analysis, histology, and immunohistochemistry may be performed with the contralateral side providing paired control data to eliminate inter-subject variability while reducing the total number of animals. Further, we present a review of existing literature of preclinical evaluation of TEVGs in large animal models as AV conduits.

Safety and efficacy of a modified HeRO dialysis device in achieving early graft cannulation: A single-institution experience

Hemodialysis Reliable Outflow (HeRO) grafts (Merit Medical Systems, Inc, South Jordan, Utah) provide a means for access in catheter-dependent hemodialysis patients but typically require several weeks for tissue incorporation. Modifying the HeRO graft with an ACUSEAL graft (W. L. Gore & Associates, Newark, Del) can allow immediate cannulation, thus reducing catheter dependence time and its associated complications. A retrospective review of patients at our institution from 2013 to 2016 who underwent placement of a modified HeRO dialysis system with ACUSEAL graft was performed. Complications and outcomes were analyzed, with patency rates and hours to successful cannulation being major end points. Modified HeRO grafts were successfully placed in 10 catheter-dependent patients. Postoperative complications included two thromboses and one hematoma. At 6 months of follow-up, mean time to graft cannulation was 33.7 hours, with 100% success; the primary and secondary patency rates were 70% and 90%, respectively. Our modification allows an accelerated use of the HeRO system, reducing catheter dependence time with acceptable postoperative complications and patency rates.

Predictors of nonfunctional arteriovenous access at hemodialysis initiation and timing of access creation: A registry-based study

Determinants of nonfunctional arteriovenous (AV) access, including timing of AV access creation, have not been sufficiently described. We studied 29 945 patients who had predialysis AV access placement and were included in the French REIN registry from 2005 through 2013. AV access was considered nonfunctional when dialysis began with a catheter. We estimated crude and adjusted odds ratio (OR) with 95% confidence intervals (CI) of nonfunctional versus functional AV access associated with case-mix, facility characteristics, and timing of AV access creation. Analyses were stratified by dialysis start condition (planned or as an emergency) and comorbidity profile. Overall, 18% patients had nonfunctional AV access at hemodialysis initiation. In the group with planned dialysis start, female gender (OR 1.43, 95% CI 1.32–1.56), diabetes (OR 1.28, 95% CI 1.15–1.44), and a higher number of cardiovascular comorbidities (OR 1.27, 95% CI 1.09–1.49, and 1.31, 1.05–1.64, for 3 and >3 cardiovascular comorbidities versus none, respectively) were independent predictors of nonfunctional AV access. A higher percentage of AV access creation at the region level was associated with a lower rate of nonfunctional AV access (OR 0.98, 95% CI 0.98–0.99 per 1% increase). The odds of nonfunctional AV access decreased as time from creation to hemodialysis initiation increased up to 3 months in nondiabetic patients with fewer than 2 cardiovascular comorbidities and 6 months in patients with diabetes or 2 or more such comorbidities. In conclusion, both patient characteristics and clinical practices may play a role in successful AV access use at hemodialysis initiation. Adjusting the timing of AV access creation to patients’ comorbidity profiles may improve functional AV access rates.

Risk factors for in-hospital mortality in patients starting hemodialysis

BACKGROUND

Incident hemodialysis patients have the highest mortality in the first several months after starting dialysis. This study evaluated the in-hospital mortality rate after hemodialysis initiation, as well as related risk factors.

METHODS

We examined in-hospital mortality and related factors in 2,692 patients starting incident hemodialysis. The study population included patients with acute kidney injury, acute exacerbation of chronic kidney disease, and chronic kidney disease. To determine the parameters associated with in-hospital mortality, patients who died in hospital (nonsurvivors) were compared with those who survived (survivors). Risk factors for in-hospital mortality were determined using logistic regression analysis.

RESULTS

Among all patients, 451 (16.8%) died during hospitalization. The highest risk factor for in-hospital mortality was cardiopulmonary resuscitation, followed by pneumonia, arrhythmia, hematologic malignancy, and acute kidney injury after bleeding. Albumin was not a risk factor for in-hospital mortality, whereas C-reactive protein was a risk factor. The use of vancomycin, inotropes, and a ventilator was associated with mortality, whereas elective hemodialysis with chronic kidney disease and statin use were associated with survival. The use of continuous renal replacement therapy was not associated with in-hospital mortality.

CONCLUSION

Incident hemodialysis patients had high in-hospital mortality. Cardiopulmonary resuscitation, infections such as pneumonia, and the use of inotropes and a ventilator was strong risk factors for in-hospital mortality. However, elective hemodialysis for chronic kidney disease was associated with survival.

Major bleeding events and risk stratification of antithrombotic agents in hemodialysis: results from the DOPPS

Benefits and risks of antithrombotic agents remain unclear in the hemodialysis population. To help clarify this we determined variation in antithrombotic agent use, rates of major bleeding events, and factors predictive of stroke and bleeding in 48,144 patients in the Dialysis Outcomes and Practice Patterns Study (DOPPS) phases I-IV. Antithrombotic agents including oral anticoagulants (OACs), aspirin (ASA), and anti-platelet agents (APAs) were recorded along with comorbidities at study entry, and clinical events including hospitalization due to bleeding were then collected every 4 months. There was wide variation in OAC (0.3-18%), APA (3-25%), and ASA use (8-36%), and major bleeding rates (0.05-0.22 events/year) among countries. All-cause mortality, cardiovascular mortality, and bleeding events requiring hospitalization were elevated in patients prescribed OACs across adjusted models. The CHADS2 score predicted the risk of stroke in atrial fibrillation patients. Gastrointestinal bleeding in the past 12 months was highly predictive of major bleeding events; for patients with previous gastrointestinal bleeding, the rate of bleeding exceeded the rate of stroke by at least twofold across all categories of CHADS2 score, including patients at high stroke risk. Appropriate risk stratification and a cautious approach should be considered before OAC use in the dialysis population.

Accumulation of retained nonfunctional arteriovenous grafts correlates with severity of inflammation in asymptomatic ESRD patients

BACKGROUND

The contribution of multiple retained nonfunctional arteriovenous grafts (AVGs) to the burden of chronic inflammation in chronic hemodialysis patients has not been well studied. Here, we sought to evaluate the association between plasma levels of C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-alpha) and albumin and the number of retained nonfunctional AVGs.

METHODS

This cross-sectional study enrolled 91 prevalent patients undergoing in-center hemodialysis without evidence of infection or inflammation. A baseline blood sample was obtained at study enrollment. A general linear model (GLM) was used to compare levels of biomarkers of systemic inflammation across groups defined by the number of retained, nonfunctional AVGs.

RESULTS

A total of 43 patients had one or more retained thrombosed AVG and had significantly greater plasma log-CRP levels compared with patients without a previous AVG (P= 0.036), regardless of the current AV access type. Using a GLM, we found that for every additional retained thrombosed AVG, plasma log-CRP, log-IL-6 and TNF-alpha concentrations increased significantly by 0.30 mg/L (P= 0.011), 0.18 pg/mL (P= 0.046) and 0.72 pg/mL (P= 0.046), respectively, following adjustment.

CONCLUSIONS

Hence, the severity of inflammation increases with the number of retained nonfunctional AVG's, suggesting that AVG accumulation may contribute to the cardiovascular morbidity and mortality associated with chronic inflammation in asymptomatic end-stage renal disease (ESRD) patients. Further study is indicated to determine whether patients with one or more thrombosed, retained AVG may benefit from periodic screening with CRP monitoring to identify those patients who may benefit from AVG resection.

Vascular access type, health-related quality of life, and depression in hemodialysis patients: a preliminary report

PURPOSE

Arteriovenous fistulas (AVF) are the vascular access of choice for hemodialysis (HD) compared with arteriovenous grafts (AVG) and central venous catheters (CVC). In spite of increasing recognition of importance of a patient's perception of health-related quality of life (HRQOL) and depression, few studies have assessed the association of vascular access type with HRQOL and depression. The purpose of our study was to examine HRQOL and depression among patients with different vascular access.

METHODS

Severity of symptoms of depression and HRQOL were assessed by Beck Depression Inventory (BDI) and Short Form-36 (SF-36), respectively. Vascular access was reported as one of three options; AVF, AVG, and CVC.

RESULTS

In total, 136 patients were included; 104 had AVF, 15 had AVG, and 17 had CVC. BDI and HRQOL parameters differed among patients with different vascular access types. In post hoc analysis, BDI and HRQOL subscales were not different between patients with AVF and AVG. Patients with CVC had lower physical functioning (P:.001), role-physical limitation (P:.015), general health perception (P:.017), vitality (P:.010), social functioning (P:.004), role-emotional (P:.008), mental health (P:.001), physical component summary score (P:.017), and mental component summary score (P:.006) when compared to patients with AVF. Patients with CVC had lower physical functioning (P:.044), role-emotional (P:.044) and mental health scores (P:.04) when compared to patients with AVG.

CONCLUSIONS

Having a CVC may negatively influence HRQOL in HD patients. Vascular access type does not seem to be related to depressed mood in HD.

CathAway fistula vascular access program achieves improved outcomes and sets a new standard of treatment for end-stage renal disease

Hemodialysis patients using central venous catheters (CVCs) for vascular access are at greater risk of infection and death vs. arterial venous fistula (AVF). In 2008, DaVita initiated the CathAway quality improvement initiative, a multidisciplinary program to reduce CVC use in favor of AVF. Our retrospective analysis examined CVC use for incident (≤90 days) and prevalent (>90 days) patients receiving hemodialysis in the years 2006 to 2010. Outcomes included annual mean percentage of patients with CVCs, new CVC placements per 100 patient years, CVC survival, and percentage patient days with CVC. Over 152,000 patient records were reviewed. Between 76.2% and 79.7% of incident patients used a CVC annually, but for prevalent patients, the proportion decreased from 41.1% in 2006 to 33.5% in 2010. The number of new CVC placements per 100 patient years increased slightly for incident patients but fell annually from 64.8 in 2006 to 55.2 in 2010 for prevalent patients. The percentage of treatment days with CVCs was stable among incident patients (70.4%-74.3%) but fell among prevalent patients from 26.1% in 2006 to 16.5% in 2010. The mean duration of CVC use in incident patients was between 53.0 days (SD, 27.8) in 2006 and 54.1 days (SD, 28.1) in 2009, and for prevalent patients between 158.9 days (SD, 123.0) in 2006 and 128.1 days (SD, 112.0) in 2010. CathAway significantly decreased CVC use in prevalent hemodialysis patients. Decreasing incident patient use will require improvements in predialysis care.

Patterns and predictors of early mortality in incident hemodialysis patients: new insights

BACKGROUND

Incident hemodialysis patients have the highest mortality in the first several months after starting dialysis treatments. We hypothesized that the patterns and risk factors associated with this early mortality differ from those in later dialysis therapy periods.

METHODS

We examined mortality patterns and predictors during the first several months of hemodialysis treatment in 18,707 incident patients since the first week of hemodialysis therapy and estimated the population attributable fractions for selected time periods in the first 24 months.

RESULTS

The 18,707 incident hemodialysis patients were 45% women and 54% diabetics. The standardized mortality ratios (95% confidence interval) in the 1st to 3rd month of hemodialysis therapy were 1.81 (1.74-1.88), 1.79 (1.72-1.86), and 1.34 (1.27-1.40), respectively. The standardized mortality ratio reached prevalent mortality only by the 7th month. No survival advantage for African Americans existed in the first 6 months. Patients with low albumin <3.5 g/dl had the highest proportion of infection-related deaths while patients with higher albumin levels had higher cardiovascular deaths including 76% of deaths during the first 3 months. Use of catheter as vascular access and hypoalbuminemia <3.5 g/dl explained 34% (17-54%) and 33% (19-45%) of all deaths in the first 90 days, respectively.

CONCLUSIONS

Incident hemodialysis patients have the highest mortality during the first 6 months including 80% higher death risk in the first 2 months. The presence of a central venous catheter and hypoalbuminemia <3.5 g/dl each explain one third of all deaths in the first 90 days.

Seeing Eye to Eye: The Key to Reducing Catheter Use

Purpose

Hemodialysis central venous catheters (CVCs) are increasingly used, despite a prevalence target of <10%. The primary aim of our study was to understand why patients persistently use their CVCs.

Methods

A multicenter prospective observational study surveyed 322 patients and their vascular access coordinators (VACs) to determine the reasons patients use CVCs. Their responses were compared using multirater kappa statistics. An 18–month follow-up survey was applied to a subgroup of patients consistently using their CVCs, and correlated with the VACs' and patients' previous responses. Predictive associations for specific reasons for CVC use were explored.

Results

Patients indicated “non-medical” reasons (34.8%), having previously failed fistulas/grafts (25.8%), and fear of disfiguration (11.5%) as the main reasons for CVC use. The VAC was in agreement with the patient 16.5% of the time, in partial agreement 37.0%, and in disagreement 46.5%. Twelve percent of patients indicated a desire to change their CVC, yet the VAC was unaware of this 78% of the time.

Conclusions

The primary reasons patients use CVCs are “non-medical” followed by concerns with the complications and esthetic appearance associated with fistulas/grafts. The significant discordance between the reasons the patients give and the VACs view of patient reasons for CVC use suggests a gap in knowledge, understanding, or communication between patients and their VACs. Timely predialysis education to address this gap and realistic targets are necessary to reduce CVC prevalence.

Tunneled dialysis catheters: recent trends and future directions

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.