Prospective multicenter study with a 1-year analysis of a new vascular graft used for early cannulation in patients undergoing hemodialysis

Prospective multicenter study of a novel endovascular venous anastomotic procedure and device for implantation of an arteriovenous graft for hemodialysis

INTRODUCTION

The traditional sutured venous anastomosis used during arteriovenous graft implantation is associated with a high incidence of subsequent stenosis that is attributed to neointimal hyperplasia. Hyperplasia results from multiple factors, including hemodynamic abnormalities and vessel trauma during implantation. A novel anastomotic connector device was designed to provide an alternative, less traumatic, endovascular venous anastomosis that may ameliorate the clinical challenges associated with a sutured anastomosis. A prospective single-arm multicenter study was performed to evaluate safety and effectiveness of graft implantation using the study device.

METHODS

Patients requiring graft creation and who met the study criteria were enrolled between February 2018 and July 2021 and observed for 6 months. Collected data included baseline characteristics, graft patency and use for hemodialysis, graft interventions, and adverse events. The primary study endpoint was cumulative graft patency, compared to a pre-specified Performance Goal of 75%. Secondary endpoints included primary unassisted patency and serious adverse events, defined as the occurrence of death, graft infection, emergent surgery, significant bleeding, and pseudoaneurysm.

RESULTS

A total of 158 patients were enrolled from 10 study sites, among which 144 subjects were evaluable at 6 months and 14 were censored with partial follow-up observation. Three patients died and the graft was abandoned in 12. The primary endpoint was met (p-value < 0.001). By Kaplan Meier survival analysis, cumulative patency was 92.08% with a lower 95% Confidence Bound of 86.98%. Primary unassisted patency was 60.21% with a lower 95% Confidence Bound of 50.84%. Graft infections occurred in six patients, all unrelated to the study device. There were no reports of emergent surgery, significant bleeding or pseudoaneurysm.

CONCLUSION

These results demonstrate that the study device can be used for successful endovascular anastomosis of a vein to a graft for hemodialysis, with acceptable cumulative patency and safety profile at 6 months.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02532621.

Quality assurance in surgical trials of arteriovenous grafts for haemodialysis: A systematic review, a narrative exploration and expert recommendations

BACKGROUND

Introducing new procedures and challenging established paradigms requires well-designed randomised controlled trials (RCT). However, RCT in surgery present unique challenges with much of treatment tailored to the individual patient circumstances, refined by experience and limited by organisational factors. There has been considerable debate over the outcomes of arteriovenous grafts (AVG) compared to AVF, but any differences may reflect differing practice and potential variability. It is essential, therefore, when considering an RCT of a novel surgical procedure or device that quality assurance (QA) is defined for both the new approach and the comparator. The aim of this systematic review was to evaluate the QA standards performed in RCT of AVG using a multi-national, multi-disciplinary approach and propose an approach for future RCT.

METHOD

The methods of this have been previously registered (PROSPERO: CRD420234284280) and published. In summary, a four-stage review was performed: identification of RCT of AVG, initial review, multidisciplinary appraisal of QA methods and reconciliation. QA measures were sought in four areas - generic, credentialing, standardisation and monitoring, with data abstracted by a multi-national, multi-speciality review body.

RESULTS

QA in RCT involving AVG in all four domains is highly variable, often sub-optimally described and has not improved over the past three decades. Few RCT established or defined a pre-RCT level of experience, none documented a pre-trial education programme, or had minimal standards of peri-operative management, no study had a defined pre-trial monitoring programme, and none assessed technical performance.

CONCLUSION

QA in RCT is a relatively new area that is expanding to ensure evidence is reliable and reproducible. This review demonstrates that QA has not previously been detailed, but can be measured in surgical RCT of vascular access, and that a four-domain approach can easily be implemented into future RCT.

Options for Dialysis and Vascular Access Creation

End-stage kidney disease (ESKD) affects nearly 800,000 patients in the United States. The choice of peritoneal dialysis (PD) versus hemodialysis (HD) should be patient centric. An ESKD Life-Plan is crucial with the goal of creating the right access, for the right patient, at the right time, for the right reason. Complex access should be considered when straightforward access options have been exhausted. Evolving techniques such as percutaneous access for HD and PD should be further investigated. Shared decision-making and palliative care is an essential part of the care of patients with CKD and ESKD..

Surgical management of an infected external iliac artery interposition graft with a bioengineered human acellular vessel

Infection of prosthetic vascular grafts can manifest as pain, pseudoaneurysms, or arterial insufficiency in the leg. We present the case of a female patient with a medical history of a right external iliac artery endofibrosis, with a persistently infected synthetic iliofemoral bypass graft, which we replaced with a bioengineered human acellular vessel. At the 12-month follow-up visit, the clinical and radiologic studies demonstrated adequate human acellular vessel patency, with no signs of infection, stenosis, or pseudoaneurysm. Subsequent to the initiation of hormone therapy and cessation of antiplatelet therapy, the patient developed graft thrombosis. She continued to do well after restoration of patency with lytic therapy. At 22 months, secondary patency has been maintained with continued anticoagulation therapy, and the patient has remained asymptomatic.

Pediatric hemodialysis access

Pediatric hemodialysis access is a demanding field. Procedures are infrequent, technically challenging, and associated with high complication and failure rates. Each procedure affects subsequent access and transplants sites. The choice is made easier and outcomes improved when access decisions are made by a multidisciplinary, pediatric, hemodialysis access team. This manuscript reviews the current literature and offers technical suggestions to improve outcomes.

Single-Institution Learning Curve for Management of Mega-Fistulae Revision

Mega-fistulae are generalized aneurysmal dilations of a high flow (1500-4000 mL/min) autogenous arteriovenous (AV) access which may result in hemorrhage and/or high-output cardiac failure. Current treatment options for mega-fistula include ligation with and without prosthetic jump graft, aneurysmorrhaphy, aneurysmectomy with vein transposition, and imbrication. These options may not be suitable for advanced disease; may leave the patient without working AV access, poor cosmetic results, and possible recurrence. We describe our early experience with a technique of complete mega-fistula resection and replacement with an early use prosthetic graft that both maintains existing AV access and eliminates the need for long-term catheter placement; including lessons learned.

Early cannulation versus standard arteriovenous grafts in hemodialysis patients: a randomized clinical study

OBJECTIVE

Arteriovenous grafts (AVGs) are frequently needed in hemodialysis (HD) patients with unsuitable superficial veins. First cannulation of standard arteriovenous grafts (sAVGs) still require about 2 weeks after implantation. Early cannulation arteriovenous grafts (eAVGs) were suggested to overcome this shortcoming. The present randomized study proposed to compare the clinical outcomes of sAVGs and eAVGs in HD patients.

METHODS

The present single-center randomized clinical study recruited 477 HD patients indicated for AVG creation. They included 236 in the sAVG group and 241 in the eAVG group. Eligible patients were simply randomized and allocated to the studied groups using 1:1 allocation ratio. Blinding was secured using the sealed envelope technique. Enrolled patients were followed up for 12 months. The primary outcome in the present study was primary, primary assisted, and secondary patency rates at 12 months. Other outcome parameters included time to first cannulation, graft complications, and mortality.

RESULTS

Comparison between the studied groups regarding the primary outcomes revealed no statistically significant differences. Primary patency rate was 65.7% and 68.0% (P = .58) at 6 months and 53.8% and 56.4% (P = .57) at 12 months in the sAVG and eAVG groups, respectively. Primary assisted patency rate was 70.8% and 69.7% (P = .8) in patients with sAVG and eAVG, whereas the reported rates at 12 months were 59.3% and 61.0% (P = .71), respectively. Secondary patency rate was 78.4% and 73.9% (P = .25) at 6 months and 67.8% and 69.7% (P = .65) at 12 months in the sAVG and eAVG groups, respectively. As expected, patients in the eAVG group experienced significantly earlier cannulation when compared with patients in the sAVG group (median, 3.0 days; range, 1.0-9.0 days vs 19.0 days; range, 15.0-22.0 days; P < .001).

CONCLUSIONS

Patients in the eAVG group have comparable outcomes to those in the sAVG group at 12 months with the added advantage of earlier time to first cannulation.

Early cannulation arteriovenous graft (Acuseal) versus standard arteriovenous graft in patients with end-stage renal disease

INTRODUCTION

The use of Acuseal arteriovenous graft (AAVG) is spreading in end-stage renal disease (ESRD) patients for its advantages in early cannulation. However, comparison of clinical outcomes between AAVGs and standard arteriovenous grafts (SAVGs) is limited. In this study, we compared the performance of AAVGs and SAVGs.

METHODS

Consecutive ESRD patients underwent prosthetic vascular access between October 2017 and May 2019 at a single center were identified. Patients were divided into AAVG group and SAVG group. Patients' demographics, perioperative characteristics, and clinical outcomes were collected. Primary, primary assisted, and secondary patency rates were compared using Kaplan-Meier analyses. Postsurgery complications were compared using chi-square test or the Fisher's exact test.

FINDINGS

A total of 304 arteriovenous grafts (AVGs) were implanted in 145 males and 159 females (mean age, 60.1 years; range, 20-91 years), comprising 143 AAVGs and 161 SAVGs. Median time to first cannulation was 3 days (interquartile range [IQR], 1-15 days) in the AAVG group and 30 days (IQR, 20-52 days) in the SAVG group (P < 0.001). Adjusted primary, primary assisted, and secondary patency at 12 months were not significant different between AAVGs and SAVGs (P = 0.911, P = 0.945, and P = 0.640, respectively). There was no statistical significance in regards to thrombosis (AAVG, 34.3%; SAVG, 26.1%; P = 0.120) and infection (AAVG, 4.9%; SAVG, 2.5%; P = 0.261) between the groups.

DISCUSSION

Acuseal grafts provide comparable patency, and complication rates to SAVGs, with less time to first cannulation from the graft implanted.

Patient characteristics predict patency of early-cannulation arteriovenous grafts

There is a new emphasis on tailoring appropriate vascular access for hemodialysis to patients and their life-plans, but there is little known about the optimal use of newer devices such as early-cannulation arteriovenous grafts (ecAVG), with studies utilising them in a wide variety of situations. The aim of this study was to determine if the outcome of ecAVG can be predicted by patient characteristics known pre-operatively. This retrospective analysis of 278 consecutive ecAVG with minimum one-year follow-up correlated functional patency with demographic data, renal history, renal replacement and vascular access history. On univariate analysis, aetiology of renal disease, indication for an ecAVG, the number of previous tunnelled central venous catheters (TCVC) prior to insertion of an ecAVG, peripheral vascular disease, and BMI were significant associates with functional patency. On multivariate analysis the number of previous TCVC, the presence of peripheral vascular disease and indication were independently associated with outcome after allowing for age, sex and BMI. When selecting for vascular access, understanding the clinical circumstances such as indication and previous vascular access can identify patients with differing outcomes. Importantly, strategies that result in TCVC exposure have an independent and cumulative association with decreasing long-term patency for subsequent ecAVG. As such, TCVC exposure is best avoided or minimised particularly when ecAVG can be considered.

Evaluation of heparin-bonded ePTFE grafts for forearm loop vascular access: Comparison between Gore® PROPATEN vascular graft and ACUSEAL vascular graft

BACKGROUND

This retrospective study evaluates the clinical outcomes of two heparin-bonded expanded polytetrafluoroethylene grafts, PROPATEN and ACUSEAL (W. L. Gore & Associates, Flagstaff, AZ, USA), for forearm loop vascular access.

METHODS

We prospectively collected data on 60 patients who had undergone arteriovenous graft of the forearm loop type between January 2015 and December 2019. The primary endpoints were graft primary, assisted primary, and secondary patency rates. Secondary endpoints were time to first cannulation and postoperative complications.

RESULTS

We enrolled 36 patients in the PROPATEN group (Group P) and 24 in the ACUSEAL group (Group A). All procedures were successful without any 30-day mortality. The median times to first cannulation were 16.5 days and 3 days in Groups P and A, respectively (p < 0.001). Mean follow-up periods were 13.4 ± 14.5 and 17.3 ± 9.3 months, respectively. Primary patency rates were 81% and 64%, respectively, at 6 months, and 60% and 40%, respectively, at 12 months (p = 0.008). Assisted primary patency rates were 96% and 83% at 6 months, 91% and 73% at 12 months, and 81% and 35% at 24 months (p = 0.044). Secondary patency rates were 96% and 81% at 12 months, and 87% and 62% at 24 months (p = 0.207). As a remote-period complication, disruption of the luminal layer of the graft was observed in two patients (4.2%) in Group A due to puncture and thrombectomy.

CONCLUSIONS

Although the ACUSEAL graft offers the advantage of early cannulation, its primary and assisted primary patency outcomes were inferior to those of the PROPATEN graft. It is important for physicians to be aware of the different characteristics of each graft to select the best option for each patient.

Patency of ePTFE Arteriovenous Graft Placements in Hemodialysis Patients: Systematic Literature Review and Meta-Analysis

Arteriovenous grafts (AVGs) are an appropriate option for vascular access in certain hemodialysis patients. Expanded polytetrafluoroethylene (ePTFE) has become the dominant material for such grafts, due in part to innovations in graft design and surgical interventions to reduce complications and improve patency rates. Comprehensive evidence syntheses have not been conducted to update AVG performance in an era in which both access choice and ePTFE graft functioning may have changed. We conducted a systematic review and meta-analysis summarizing outcomes from recent studies of ePTFE AVGs in hemodialysis, following PRISMA standards. Literature searches were conducted in multiple databases to identify observational and interventional studies of AVG patency and infection risk. Primary, primary-assisted, and secondary patency rates were analyzed at 6, 12, 18, and 24 months postplacement. Kaplan-Meier graft survival plots were digitized to recreate individual patient-level data. Patency rates were pooled using a random effects model. We identified 32 studies meeting our selection criteria that were published from 2004 through 2019. A total of 38 study arms of ePTFE grafts were included, representing 3381 AVG accesses placed. The mean primary, primary-assisted, and secondary patency rates at 1 year were 41% (95% CI, 35% to 47%), 46% (95% CI, 41% to 51%), and 70% (95% CI, 64% to 75%), respectively. Mean 24-month patency rates were 28% (95% CI, 22% to 33%), 34% (95% CI, 27% to 41%), and 54% (95% CI, 47% to 61%), respectively. A high degree of heterogeneity across studies was observed. Overall risk of infection was not consistently reported, but among available studies the pooled estimate was 9% per patient-year (95% CI, 6% to 12%). This meta-analysis provides an up-to-date estimate of the performance of ePTFE AVGs, within the context of improved graft designs and improved interventional techniques.

Short- to midterm results of early cannulation arteriovenous grafts (Gore® ACUSEAL) for hemodialysis: Experience with the ACUSEAL in a Japanese cohort

BACKGROUND

In patients without suitable vasculature for autologous arteriovenous fistula, vascular access using a prosthetic graft is an option for hemodialysis. Gore^® ACUSEAL Vascular graft is an early cannulation arteriovenous graft (AVG) that allows early puncture within 24 h after surgery. We aimed to report the outcomes of using this graft in patients from a single center.

METHODS

This study included 113 patients who underwent surgery for a new AVG using ACUSEAL, between December 2015 and December 2017, and were followed up. The primary outcomes were primary patency, assisted-primary patency, and secondary patency. Secondary outcomes were postoperative complications such as graft infection and steal syndrome.

RESULTS

Of the 113 patients, 60 were male and 53 were female. The average age was 74.4 ± 10.7 years. We could cannulate 69.1% of patients within 24 h. The average follow-up period was 20.1 ± 10.8 months. The primary patency rates after 3 months, 6 months, and 1 year were 76.2%, 60.4%, and 33.8%, respectively. The assisted-primary patency rates after 3 months, 6 months, and 1 year were 88.8%, 73.2%, and 58.9%, respectively. The secondary patency rates after 3 months, 6 months, and 1 year were 100%, 100%, and 98.8%, respectively. Fourteen patients (12.4%) developed graft infection and two patients (1.8%) developed steal syndrome.

CONCLUSION

In our study, ACUSEAL showed satisfactory patency and acceptable complication rates in the short to medium term, similar to previous studies. ACUSEAL is beneficial for surgeons who are familiar with using AVG and for medical staff who control bleeding after dialysis. However, due to the large outer diameter of the graft, surgical wounds might become dehiscent, and careful designing of the subcutaneous graft route is necessary. It might be possible to reduce the rate of graft infection by planning the site and skin incision.

Determining the incidence of needle-related complications in hemodialysis access: We need a better system

INTRODUCTION

Hemodialysis access complications are common. We hypothesize that many of these complications can be traced back to needle-related injury from routine cannulation practices or inadvertent cannulation injuries. We set out to compare the rates of hemodialysis access complications under prior and current diagnosis coding systems, determine the incidence of needle-related complications for hemodialysis access, and describe the association of needle-related complications and resulting interventions.

METHODS

Arteriovenous graft and arteriovenous fistula placements occurring in the first 6 months of 2014 and 2016 were identified in the United States Renal Data System Medicare claims data. Placements were followed until end of hemodialysis access life or end of the calendar year. Diagnoses and resulting interventions occurring during placement life were identified and mapped to needle-related complication terms.

RESULTS

Almost 30,000 placements for 27,000 patients were followed in each year, with 67% of all accesses placed being arteriovenous fistula and 33% arteriovenous graft. In both years, 75% of arteriovenous fistulae and arteriovenous grafts required one or more interventions. Stenosis and thrombosis were the most common complications diagnosed and treated (41% and 16%, respectively); however, potential needle-related complications accounted for 6% of this dataset.

DISCUSSION

International Classification of Diseases, 9th Revision, was inadequate for determining the incidence of specific hemodialysis access complications or needle-related complications. International Classification of Diseases, 10th Revision, introduced several more hemodialysis access diagnoses but is still subject to coding confusion and catch-all coding for a variety of common and otherwise well-defined complications, suggesting that the true incidence of needle-related complications is buried in the non-specific diagnosis codes. These findings mark the clear need for an improved diagnosis coding system that consistently represents all common hemodialysis access complications.

Delamination of Acuseal early cannulation arteriovenous graft months after implantation

Arteriovenous fistula is recommended, but arteriovenous graft is acceptable when a fistula is not possible. Acuseal is an early cannulation graft with a trilayer structure. Although primary patency rates of Acuseal appear to be similar to those of other standard grafts, few studies have investigated long-term results and complications. In our series, delamination of the wall structure occurred in 5.1% (6/115) by 21 months after Acuseal implantation. The causes could be divided into cannulation-related and cannulation-unrelated. Here, we describe the six cases in which delamination of the wall structure occurred in the medium term after Acuseal implantation.

Novel Approaches to Arteriovenous Access Creation, Maturation, Suitability, and Durability for Dialysis

Since the arteriovenous fistula (AVF) was first conceived over 50 years ago, the goal to create a vascular conduit with predictable and reproducible maturation and durability continues to elude caregivers. Recently, however, advances in the understanding of vascular biology and new technologies now provides us with some optimism; we are moving toward a viable solution. A quickly maturing, sustainable, and durable arteriovenous access may soon be attainable. This review will discuss these advances. There are novel approaches to AVF creation and devices to enhance maturation, advances in arteriovenous graft material(s), and devices to safely prolong the use of tunneled dialysis catheters. Although hemodialysis (HD) access remains a complex problem, these innovations may lead the way to optimizing the care and the quality of life of those patients who have no choice but to proceed with HD.

Cost-effectiveness analysis of immediate access arteriovenous grafts versus standard grafts for hemodialysis

OBJECTIVE

Immediate-access arteriovenous grafts (IAAVGs), or early cannulation arteriovenous grafts (AVGs), are more expensive than standard grafts (sAVGs) but can be used immediately after placement, reducing the need for a tunneled dialysis catheter (TDC). We hypothesized that a decrease in TDC-related complications would make IAAVGs a cost-effective alternative to sAVGs.

METHODS

We constructed a Markov state-transition model in which patients initially received either an IAAVG or an sAVG and a TDC until graft usability; patients were followed through multiple subsequent access procedures for a 60-month time horizon. The model simulated mortality and typical graft- and TDC-related complications, with parameter estimates including probabilities, costs, and utilities derived from previous literature. A key parameter was median time to TDC removal after graft placement, which was studied under both real-world (7 days for IAAVG and 70 days for sAVG) and ideal (no TDC placed with IAAVG and 1 month for sAVG) conditions. Costs were based on current Medicare reimbursement rates and reflect a payer perspective. Both microsimulation (10,000 trials) and probabilistic sensitivity analysis (10,000 samples) were performed. The willingness-to-pay threshold was set at $100,000 per quality-adjusted life-year (QALY).

RESULTS

IAAVG placement is a dominant strategy under both real-world ($1201.16 less expensive and 0.03 QALY more effective) and ideal ($1457.97 less expensive and 0.03 QALY more effective) conditions. Under real-world parameters, the result was most sensitive to the time to TDC removal; IAAVGs are cost-effective if a TDC is maintained for ≥23 days after sAVG placement. The mean catheter time was lower with IAAVG (3.9 vs 8.7 months; P < .0001), as was the mean number of access-related infections (0.55 vs 0.74; P < .0001). Median survival in the model was 29 months. Overall mortality was similar between groups (76.3% vs 76.7% at 5 years; P = .33), but access-related mortality trended toward improvement with IAAVG (6.1% vs 6.8% at 5 years; P = .052).

CONCLUSIONS

The Markov decision analysis model supported our hypothesis that IAAVGs come with added initial cost but are ultimately cost-saving and more effective. This apparent benefit is due to our prediction that a decreased number of catheter days per patient would lead to a decreased number of access-related infections.

Single-centre experience of an early cannulation graft for haemodialysis access

INTRODUCTION

As the demographics of the population changes, increasing challenges are being faced in providing reliable access for dialysis. This article reports on the outcomes from the largest series to date using the early cannulation graft Flixene in a single centre.

METHODS

Between May 2012 and March 2018, 141 Flixene grafts were placed for dialysis access. The outcomes of the arteriovenous grafts were reviewed retrospectively from electronically held records and imaging.

RESULTS

In 75 patients, placement of Flixene graft was performed on an emergency basis and in 66 patients on a planned elective list. The 12-month primary, assisted primary and secondary patency rates were 48.7%, 56.6% and 83.6%, respectively. Eight (5.7%) patients developed infections of the graft during the follow-up period.

CONCLUSION

In our experience, we have found the use of the early cannulation graft Flixene to be safe with a low complication rate and favourable patency rates. We believe these early cannulation grafts provide a useful addition for vascular access surgeons preventing the use of tunnelled lines and providing more flexibility in the timing of placing a graft for dialysis.

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.

Impact of Early Cannulation Grafts on Quality and Cost of Care for Patients With End-Stage Renal Disease

BACKGROUND

The annual cost of care associated with end-stage renal disease (ESRD) per patient on hemodialysis is approaching $100,000, with nearly $42 billion in national spend per year. Early cannulation arteriovenous grafts (ECAVGs) help decrease the use of central venous catheters (CVCs), thus potentially decreasing the cost of care. However, a formal financial analysis that also includes the cost of CVC-related complications and secondary interventions has not been completed. The purpose of this project is to evaluate the overall financial costs associated with ECAVGs on patients with ESRD during a one-year period.

METHODS

Access modality, complications, secondary interventions, hospital outcomes, and cost of care were determined for 397 sequential patients who underwent access creation between July 2014 and October 2018. A detailed financial analysis was completed, including an evaluation of implant, supplies, medications, laboratories, labor, and other direct costs. All variables were measured at the time of the index procedure, 30 days, 90 days, 180 days, 270 days, and one year.

RESULTS

There were 131 patients who underwent arteriovenous fistula (AVF) and 266 who underwent ECAVG for dialysis access. The average cost of care was $17,523 for AVF and $5,894 for ECAVG at one year (P < 0.01). Fewer CVC-related complications and secondary interventions associated with ECAVGs saved $11,630 per patient with ESRD, primarily in the form of supply costs. Fewer CVCs in the patients receiving ECAVGs led to an additional $1,083 decrease in cost associated with sepsis reduction at one year. A subsequent decrease in length of stay and ICU utilization led to an additional $2.0 million decrease in annual cost of care for patients with ESRD.

CONCLUSIONS

The use of ECAVGs has significant cost savings over using an AVF and CVC for urgent-start dialysis in patients with ESRD. This cost savings is secondary to decreased CVC-related complications and fewer secondary interventions. Significant national savings are possible with appropriate use of ECAVGs in patients with ESRD.

Early Cannulation of Bovine Carotid Artery Graft Reduces Tunneled Dialysis Catheter-Related Complications: A Comparison of Bovine Carotid Artery Graft Versus Expanded Polytetrafluoroethylene Grafts in Hemodialysis Access

INTRODUCTION:

In patients who receive chronic hemodialysis but do not have autogenous venous conduit for a native dialysis access, nonautologous grafts serve as an alternative conduit of choice. This study compared the clinical outcome of hemodialysis access using bovine carotid artery graft (BCAG) and prosthetic polytetrafluoroethylene (PTFE) graft in patients who receive chronic hemodialysis.

METHODS:

An analysis of all patients undergoing hemodialysis using either BCAG or PTFE grafts from 2010 to 2017 was performed. Clinical outcomes were analyzed including graft patency as well as associated complications related to dialysis grafts and tunneled dialysis catheter (TDC).

RESULTS:

During the study period, 142 patients received BCAG and 128 patients received PTFE graft implantation for dialysis access. The mean duration from graft implantation to graft cannulation in the BCAG and PTFE group was 12.3 ± 8.5 days versus 43.5 ± 16.4, respectively ( P = .01). Bovine carotid artery graft group had a higher 2-year primary patency rate (33% vs 14%, P = .03) and assisted primary rate (57% vs 23%, P = .02) compared to the PTFE group. The 2-year secondary patency rates were similar between the 2 groups (56% vs 53%, P = .69). Complication rates in the BCAG and PTFE group was 1.69 ± 0.24 per patient-year versus 2.54 ± 0.48 per patient-year, respectively ( P = .01). Tunneled dialysis catheter-related infection was greater in the PTFE group compared to the BCAG group (10.87 ± 2.61 vs 5.69 ± 0.98 per 1000 TDC days; P = .02). Bovine carotid artery graft cohorts group required a mean of 1.69 interventions per patient-year, compared to 2.76 per patient-year for the PTFE group ( P = .03).

CONCLUSIONS:

Bovine carotid artery graft permits earlier cannulation for hemodialysis access with superior primary and assisted primary patency rates compared to PTFE grafts. Patients with BCAG experienced shorter indwelling TDC duration and less TDC-related complications compared to PTFE cohorts.

Successful use of arterio-venous graft for hemodialysis in patient with hemophilia

Hemodialysis (HD) is not the preferred approach for dialysis in patients with hemophilia. HD in such patients can possess a high risk of bleeding from arterio-venous cannulation and hence peritoneal dialysis is the first choice in patients with hemophilia. The bleeding risk can be overcome by the prophylactic administration of factor VIII, which is a very costly solution. Here, we present a case of hemophilia with successful HD using an arterio-venous graft averting the need for factor VIII. We review the literature on epidemiology and risk factors for chronic kidney disease in patients with hemophilia. We also discuss the dialysis and arterio-venous graft options. In patients with hemophilia who are not candidates for peritoneal dialysis, tri-layered arterio-venous grafts offer distinct advantages.

Immediate-access grafts provide comparable patency to standard grafts, with fewer reinterventions and catheter-related complications

BACKGROUND

No independent comparisons, with midterm follow-up, of standard arteriovenous grafts (SAVGs) and immediate-access arteriovenous grafts (IAAVGs) exist. The goal of this study was to compare "real-world" performance of SAVGs and IAAVGs.

METHODS

Consecutive patients who underwent placement of a hemodialysis graft between November 2014 and April 2016 were retrospectively identified from the electronic medical record and Vascular Quality Initiative database at two tertiary centers. Only primary graft placements were included for analysis. Patients were divided into two groups based on the type of graft implanted. Patients' comorbidities, graft configuration, operative characteristics, and follow-up were collected and analyzed with respect to primary and secondary patency. Additional outcomes included graft-related complications, time to first cannulation, time to tunneled catheter removal, catheter-related complications, and overall survival. Patency was determined from the time of the index procedure; χ², Kaplan-Meier, and Cox regression analyses were used, with the P value set as significant at < .05.

RESULTS

There were 210 grafts identified, 148 SAVGs and 62 IAAVGs. At baseline, the patients' characteristics were similar between groups, except for a greater prevalence of preoperative central venous occlusions in the IAAVG group (16.3% vs 6.8%; P < .04). Of the IAAVG group, 50 were Acuseal (W. L. Gore & Associates, Flagstaff, Ariz) and 12 were Flixene (Atrium Medical Corporation, Hudson, NH). Primary patency was similar at both 1 year (SAVG, 39.4%; IAAVG, 56.7%; P = .4) and 18 months (SAVG, 29.0%; IAAVG, 43.7%; P = .4). Secondary patency was similar at 1 year (SAVG, 50.7%; IAAVG, 52.1%; P = .73) and 18 months (SAVG, 42.3%; IAAVG, 46.3%; P = .73). Overall survival was 48% at 24 months. IAAVG patients required fewer overall additional procedures to maintain patency (mean number of procedures, 0.99 for SAVGs vs 0.61 for IAAVGs; P = .025). There was no difference in occurrence of steal syndrome (SAVG, 6.8%; IAAVG, 8.1%; P = .74) or graft infection (SAVG, 19.0%; IAAVG, 12.0%; P = .276). Seventy-five percent of all grafts were successfully cannulated, with shorter median time to first cannulation in the IAAVG group (6 days; interquartile range [IQR], 1-19 days) compared with the SAVG group (31 days; IQR, 26-47 days; P < .01). Of all pre-existing catheters, 65.75% were removed, with a shorter median time until catheter removal in the IAAVG cohort at 34 days (IQR, 22-50 days) vs 49 days (IQR, 39-67 days) in the SAVG group (P < .01). Catheter-related complications occurred less frequently in the IAAVG group (16.4% vs 2.9%; P < .045).

CONCLUSIONS

IAAVGs allow earlier cannulation and tunneled catheter removal, thereby significantly decreasing catheter-related complications. Patency and infection rates were similar between SAVGs and IAAVGs, but fewer secondary procedures were performed in IAAVGs.

Good long-term patency: 10-year follow-up using the mid-thigh adductor loop arteriovenous graft

Introduction:

Definitive access in patients requiring renal replacement therapy is an ever-increasing challenge. For those where autogenous venous access is no longer a viable option, arteriovenous grafts can be considered. This article describes long-term follow-up, complications and patency rates of the mid-thigh ‘adductor loop’ arteriovenous graft.

Methods:

50 mid-thigh loop arteriovenous grafts have been inserted into 48 patients in our unit over the past 11 years. A prospective database was collected on patients receiving an arteriovenous graft at our unit by the senior author. All remained under the care of our unit ensuring accurate follow-up data collection and database was updated at regular intervals.

Results:

Death-only censored primary patency at 1, 3 and 5 years was 76%, 44% and 23%, respectively. Patients receiving transplants were not censored as follow-up of the arteriovenous grafts was possible. Secondary patency at 1, 3 and 5 years was 95%, 63% and 45%. These rates are higher than previous studies looking at lower limb arteriovenous grafts. Graft thrombosis occurred in 14 patients (28%). Six patients were treated for an infection (12%) but only four grafts were excised; much lower than documented in previous studies.

Conclusion:

Autogenous venous access remains the perceived gold standard for patients requiring dialysis for end stage renal failure, despite some published data reporting poor outcomes. We have shown that adductor loop arteriovenous grafts can be a reliable, safe and long-term alternative in those whom fistula formation is not possible and may have a role earlier in the patient journey than previously thought, as a result of good patency and lower complications.

Current Experience and Midterm Follow-up of Immediate-Access Arteriovenous Grafts

BACKGROUND

No independent reviews, with midterm follow-up, of current experience with immediate-access arteriovenous grafts (IAAVGs) exist. The goal of this project was to assess the real-world performance of 2 different IAAVGs over a 2-year period at a large tertiary referral center.

METHODS

Between January 2014 and April 2016, all consecutive patients who underwent placement of Acuseal (Gore) or Flixine (Maquet) IAAVGs were identified for retrospective analysis from the electronic medical record and Vascular Quality Initiative database. Primary, primary-assisted and secondary patency rates, time to first cannulation, time to tunneled catheter removal, and overall survival were recorded.

RESULTS

Forty-three patients were identified to have undergone placement of IAAVG, 31 Acuseal (72%), and 12 Flixine (28%). Of the Acuseal cohort, 7 were implanted with outflow through a HeRO catheter system (Merit Medical). Mean follow-up time was 8.4 months. Overall survival was 57.4% at 18 months. Overall primary, primary assisted, and secondary patency at 18 months were 33.36%, 34.31%, and 51.03%, respectively. Eighty three percent of grafts were successfully cannulated, and 78% of preexisting catheters were removed. Mean time to successful graft cannulation and catheter removal were 14.85 and 32.26 days, respectively.

CONCLUSIONS

Real-world experience with novel arteriovenous access grafts is consistent with results from industry-sponsored studies. Early cannulation of immediate-access grafts can be successfully performed in a wide variety of patients. However, prolonged catheter dwell times persist despite increased rates of successful early-graft cannulation. Further study of methods for promoting catheter removal in this patient population is warranted.

Early cannulation of bovine carotid artery grafts (Artegraft) after primary vascular access and fistula revision procedures

OBJECTIVE

Tunneled dialysis catheter (TDC) use has been associated with increased infectious complications and mortality in hemodialysis-dependent patients. Unfortunately, patients who undergo fistula revisions or creation of a new arteriovenous fistula frequently require a TDC during the postoperative period. Bovine carotid artery grafts (BCAGs) can be used as an early-access dialysis conduit to reduce TDC dependence. This study describes the performance of BCAGs that were cannulated early (<3 days) after implantation and associated clinical outcomes.

METHODS

BCAGs were implanted in 63 consecutive dialysis-dependent patients. Patients and dialysis centers were directly provided early cannulation instructions; 31 (49%) patients were cannulated early, and of the 31 patients cannulated early, 21 (68%) were cannulated during the first postoperative day. Early complications, primary patency, secondary patency, and TDC incidence were monitored through clinic visits, hospital records, and phone calls to dialysis centers.

RESULTS

The primary patency of BCAGs at 1 year in the early and late cannulation cohorts was 28% and 39%, respectively. The secondary patency of BCAGs at 1 year in the early and late cannulation cohorts was 74% and 77%, respectively. Early complications occurred in 11 (19%) patients who received a BCAG. There were no significant differences in complication rates between early and late cannulation patients. Of the 24 patients who underwent the operation without a pre-existing TDC, only three (13%) required TDC placement during the 30-day postoperative period.

CONCLUSIONS

BCAGs can be cannulated early without increased complication rates or a negative impact on midterm patency. Early cannulation of BCAGs obviates the need for a TDC postoperatively in dialysis-dependent patients undergoing primary vascular access or fistula revision procedures.

How arteriovenous grafts could help to optimize vascular access management

A one-size-fits-all approach to vascular access for dialysis may be prejudicial. Arteriovenous fistulae (AVF) have high primary failure, failure to mature rate, and late-stage complications making them unsuitable choice for many patients. Aging of population with chronic kidney disease (CKD) coupled with venous injury during CKD stages depletes suitable superficial veins for AVF creation. The National Institutes of Health consortium demonstrated the difficulty in attaining a functional AVF in hemodialysis patients. Recognition of flaws in AVF and the quest to reduce catheter use bring to the fore the benefits of arteriovenous grafts (AVG). Advances in catheter technologies, flow, care, and antibiotic locks have resulted in significant improvement in catheter-related infections. However, widespread recognition of catheter-related complications like central vein stenosis, metastatic infections, and exhaustion of venous access sites preclude their being a viable alternative to AVF, furthering the need to explore AVG as a substitute. Placement of "early cannulation" AVG is a catheter sparing option in patients who are likely to have inadequate fistula maturation. Advances in biohybrid technology and tissue-engineered grafts are providing a robust opportunity to develop biocompatible graft materials with minimal tissue reactivity and thrombogenicity. Xenografts (bovine carotid artery grafts) are proving to be comparable and, in many cases, better than conventional polytetrafluoroethylene material. Older age, dialysis dependence, and smaller vein size are related to the appropriateness of AVG creation. An individualized approach in selecting optimal upper extremity vascular access option using patient-specific factors while incorporating the benefits of an AVG would greatly aid in achieving low catheter usage in the dialysis population.

Early cannulation grafts for haemodialysis: An updated systematic review

Purpose:

Early cannulation grafts are specifically designed for dialysis, whereas standard expanded polytetrafluoroethylene grafts were not. There is developing collective experience and literature available to allow the assessment of outcomes of these early cannulation grafts. The aim of this review was to review the evidence for both short- and long-term outcomes of early cannulation grafts.

Methods:

Using standardized searches of electronic databases in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses, the primary outcomes for this study were primary and secondary patency rates for early cannulation grafts for dialysis at 12 months and beyond. Secondary outcomes were timing of first cannulation, rates of access thrombosis, steal syndrome, pseudo-aneurysm and infection.

Results:

A total of 19 studies were identified and included. These were divided into different graft types. Flixene™, Avflo™, Acuseal™ and Vectra™ grafts all showed that early cannulation within 72 h is possible. Twelve-month pooled primary and secondary patency rates were 43.3% (95% confidence interval: 31.6–55.4) and 73.4% (95% confidence interval: 63–82.7) for the Flixene graft, 58.2% (95% confidence interval: 48–68.1) and 79.2% (95% confidence interval: 68–88.7) for the Avflo graft, 43.6% (95% confidence interval: 30.7–56.9) and 70.5% (95% confidence interval: 49.7–87.8) for the Acuseal graft and 63.7% (95% confidence interval: 53.4–73.4) and 85.8% (95% confidence interval: 82.9–88.4) for the Vectra graft. Data for outcome beyond 12 months were limited to the more recent studies.

Conclusion:

This review confirms that early cannulation is not detrimental on the early outcome of early cannulation graft patencies. It has also shown that both Vectra and Avflo grafts have adequate long-term patencies. The data do not allow specific graft recommendations, as comparative trials would be required.

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.

Venous Hemodialysis Catheters and Cardiac Implantable Electronic Devices: Avoiding a High-Risk Combination

End-stage renal disease is frequently accompanied by cardiac comorbidity that warrants treatment with a cardiovascular implantable electronic device (permanent pacemaker or implantable cardioverter-defibrillator). In the United States, chronic hemodialysis (HD) population, cardiac implantable devices are present in up to 10.5% of patients; a venous HD catheter is utilized for blood access in 18% of prevalent patients. The concomitant presence of a venous HD catheter and cardiovascular implantable device creates a high-risk circumstance, with potential for causing symptomatic central venous stenosis, and for developing complicated endovascular infection. This dangerous combination may be avoided for many patients by utilizing nondialysis methods for management of advanced chronic kidney disease, initiating dialysis without venous catheter access, or managing cardiac rhythm disorders without use of transvenous cardiac implantable electronic devices. In those situations where the combination of a venous HD catheter and cardiac implantable device is unavoidable, there are strategies to minimize duration of venous catheter access, and to reduce risks for infectious complications. It is essential for nephrologists and cardiologists to understand the indications, alternatives, and risks involved with venous HD access and cardiac implantable devices. Coordinated management of renal disease and cardiac rhythm disorders has potential to minimize risks, improve outcomes, and substantially reduce the cost of care.

Vascular access should be tailored to the patient

A cornerstone of hemodialysis treatment is the creation of a functional and durable dialysis vascular access. Every patient with chronic kidney disease should have a plan of renal replacement therapy and access site protection. Factors having a crucial impact on vascular access selection include age, comorbidity, vessel quality, prognosis, dialysis urgency, and surgeon's preferences. Our medical group have reviewed these factors in our patients and, based on recently published data, developed a clinical decision tree for dialysis access in the chronic kidney disease patient. Vascular access care should be patient-centered with the aim to maximize patient survival without loss of vascular access options; and not focused only the primary patency rates of dialysis access procedures.

Duplex Ultrasound for the Prediction of Vascular Events Associated with Arteriovenous Fistulas in Hemodialysis Patients

Objective

To determine if duplex ultrasound (US) for arteriovenous fistulas (AVFs) can predict vascular events (VEs; thrombosis and stenosis).

Methods

Duplex US was performed for vascular access evaluation in 2557 maintenance hemodialysis (HD) patients between October 1, 2013 and March 31, 2016. Of these patients, 2184 patients were finally included in this study. AVF dysfunction was assessed using the brachial artery blood flow volume (Qa; mL/min), arterial blood flow resistance index (RI), and residual diameter of the fistula vein (RD; mm). Proximal, midpoint, and distal aspects of the fistulas were measured. The baseline measurements were the US assessments, and the endpoint was VEs requiring vascular access intervention therapy or vascular surgery. Associations of US findings and VEs were assessed with receiver operating characteristic curve analysis, log-rank analysis, and multivariate Cox hazard models.

Results

The mean Qa was 772.8 ± 441.4 mL/min; RI, 0.56 ± 0.1; and RD, 2.37 ± 1.0 mm. The optimal Qa cut-off point was calculated as 581.5 mL/min, RI cut-off as 0.56, and RD cut-off as 1.85 mm. VEs were more frequent in patients with a Qa <581.5 mL/min than in those with a Qa >581.5 mL/min (p<0.001). In multivariate analysis, Qa, ferritin, transferrin saturation, and warfarin use were significantly associated with VEs.

Conclusions

US evaluation of AVFs in HD patients is a simple method to predict the risks of thrombosis and fistula dysfunction. Qa, ferritin, transferrin saturation, and warfarin use might be associated with VEs.

Endovascular Stent Graft Repair is an Effective and Safe Alternative Therapy for Arteriovenous Graft Pseudoaneurysms

OBJECTIVE/BACKGROUND

Pseudoaneurysm formation occurs in 2-10% of hemodialysis arteriovenous grafts (AVGs). Surgical repair often requires pseudoaneurysm resection, interposition graft placement, and insertion of a catheter as a bridge. Endovascular stent graft repair is a controversial alternative therapy. This study was performed to examine the effectiveness and mid-term outcomes of stent graft repair for AVG pseudoaneurysms.

METHODS

All patients who had undergone stent graft repair for AVG pseudoaneurysms between December 2012 and July 2015 were identified from hospital medical records for retrospective analysis. Outcome measures were technical success, early and late complications, and primary and secondary patency rates.

RESULTS

A total of 37 stent graft repairs of AVG pseudoaneurysms were performed in 35 patients (42.9% men; mean age 66.9 years). The mean time from AVG creation to pseudoaneurysm repair was 69 months. The indications of treatment (as per the institutional policy) were large pseudoaneurysm (56.7%), impending rupture (27.1%), and bleeding (16.2%). Mean pseudoaneurysm diameter was 23.0 mm. The most common diameter and length of stent graft used were 7 mm (67.6%) and 50 mm (48.6%), respectively. Technical success was 100%. Only one early complication occurred after stent graft repair, which was due to recurrence of the pseudoaneurysm as a result of a short landing zone. Late complications included infection (17.1%) and thrombosis (37.1%). The 1, 6, and 12 month primary patency rates were 89.2%, 55.5%, and 22.0%, respectively. The 1, 6, and 12 month secondary patency rates were 100%, 88.6%, and 78.6%, respectively. The median follow up was 12.3 months.

CONCLUSIONS

The study demonstrates that endovascular stent graft repair is an effective and safe alternative therapy for AVG pseudoaneurysms. However, the rate of thrombosis and infection was high and needs to be balanced against open surgery in future studies.

Early cannulation of the Flixene™ arteriovenous graft

PURPOSE

The aim of this review was to search for evidence of the efficiency of early cannulation of the Flixene™ (Maquet-Atrium Medical, Hudson, NH, USA) arteriovenous graft (AVG) in the current literature and to assess its patency and complication rates.

METHODS

Searches in Pubmed, Medline, Embase and the Cochrane Library were performed using the following specific search terms: early cannulation AVG and/or Flixene™ graft. The primary outcomes were mean time to first cannulation and patency rates at 12 months. Secondary outcomes were complications.

RESULTS

Six studies reporting outcomes in a total of 260 procedures were included in this review. The median delay from intervention to first cannulation was documented in four studies and was less than 3 days. Primary assisted patency at 12 months ranged from 45% to 53% in the four documented series. In five studies, documented secondary patency at 12 months ranged from 63% to 92%. Two studies compared outcomes between traditional and Flixene™ grafts: one study reported significantly (p&lt;0.01) improved one-year patency using the Flixene™ graft, the two studies did not report significant differences in complication rates between both groups. The rate of infection and pseudo-aneurysm formation ranged from 0 to 11% and 0 to 6%, respectively.

CONCLUSIONS

This review shows that early cannulation of the Flixene™ graft within 3 days following its implantation is feasible with one-year patency and complication rates equivalent to those of conventional grafts which can be cannulated only after 2 weeks.

Early cannulation graft: Acuseal

AIM

To review the published literature on the early cannulation graft, Acuseal.

METHODS

235 reported cases have been published and reviewed. These cases are both prospective and retrospective, from either multicenter or single centers. Patency rates and complication rates were reviewed. Economic value of early cannulation grafts were also analyzed.

RESULTS

Over 135 patients were cannulated within 2.5 days after implantation. No increase in complications were noted and similar primary and secondary patency rates were observed compared to the literature. Economic evaluation both in the UK and US demonstrate benefit of this graft when compared to catheters, fistulas and other grafts.

CONCLUSION

Early stick grafts demonstrate similar patency and complication rates when compared to published literature of standard grafts.Economic benefit is also noted using this graft.