Comparison between transposed arteriovenous fistulas and arteriovenous graft for the hemodialysis patients: A meta-analysis and systematic review

It is challenging for a surgeon to determine the appropriate vascular access for hemodialysis patients whose cephalic vein is usually inaccessible. The purpose of the study is to compare the complications and patency rates between transposed arteriovenous fistulas (tAVF) and arteriovenous graft (AVG) for the hemodialysis patients. Studies were recruited from PubMed, Cochrane library, EMBASE, the web of science databases, and reviewing reference lists of related studies from the inception dates to September 2, 2021. Statistical analyses were conducted using the statistical tool Review Manager version5.3 (Cochrane Collaboration, London, UK). I2 > 50% was defined as a high degree of heterogeneity, and then a random-effects model was used. Otherwise, the fixed-effects model was used. Odds ratio with its 95% confidence interval (95% CI) was used. Thirty-three trials (26 retrospective studies, four randomized controlled trials, two prospective trials, and one controlled-comparative study) with 6430 enrolled participants were identified in our analysis. The results showed that tAVF was accompanied with lower thrombosis rate (103/1184 (8.69%) vs 257/1367 (18.80%); I2 = 45%; 95% CI, 0.34 (0.26, 0.45)) and infection rate (43/2031 (2.12%) vs 180/2147 (8.38%); I2 = 0%; 95% CI, 0.20 (0.14, 0.30)) than arteriovenous graft. The significantly better primary patency rates, secondary patency rates, and primary assisted patency rates during follow-up were found in tAVF. However, the failure rate and the prevalence of hematoma were significantly lower in AVG group. No evidence showed the rate of overall mortality, steal syndrome, and aneurysm reduced in tAVF. Our results showed that tAVF is a promising vascular access technique for hemodialysis patients whose cephalic vein is inaccessible. Our data showed that tAVF has less thrombosis, infection risk, and better patency rates when compared with AVG. However, more attentions need to be paid to transposed arteriovenous fistulas maturation and hematoma.

Comparison of Lower and Upper Extremity Arteriovenous Graft: A Retrospective Clinical Analysis with 5-Year Follow-Up

BACKGROUND

For patients in whom an upper extremity (UE) vascular access cannot be established, the lower extremity (LE) arteriovenous graft (AVG) could be selected. However, the application of LE AVG is limited owing to its high infection rate, uncertain patency time, and technical difficulties. This study aimed to compare the long-term patency rates and the incidence of vascular access complications of AVG in the LE and UE to provide a reference for the applications of AVG, especially in the LEs.

METHODS

This was a retrospective analysis of patients who successfully underwent LE or UE AVG placement from March 2016 to October 2021. Patient characteristics were collected and compared using parameter or nonparameter tests according to data type. Postoperative patency was evaluated using Kaplan-Meier test. Postoperative complication incidence density and intergroup comparison were estimated using the Poisson distribution.

RESULTS

Twenty-two patients with LE AVG and 120 patients with UE AVG were included. The 1-year primary patency rate was 67.4% (±11.0% standard error [SE]) in the LE group and 30.1% (±4.5% SE) in the UE group (P = 0.031). The assisted primary patency rate at postoperative months 12, 24, and 36 was respectively 78.6% (±9.6% SE), 65.5% (±14.4% SE), and 49.1% (±17.8% SE) in the LE group and 63.3% (±4.6% SE), 47.5% (±5.4% SE), and 30.4% (±6.1% SE) in the UE group (P = 0.137). The secondary patency rate at postoperative months 12, 24, and 36 remains 95.5% (±4.4% SE) in the LE group and 89.3% (±2.9% SE), 83.7% (±3.9% SE), and 73.0% (±6.2% SE), respectively, in the UE group (P = 0.200). Postoperative complications included stenosis, occlusion/thrombosis, infection, steal syndrome, pseudoaneurysm, severe postoperative serum swelling, and AVG exposure. The total incidence rates of postoperative complications were 0.87 (95% confidence interval [CI] 0.59-1.23) versus 1.61 (95% CI 1.45-1.79) (P = 0.001) cases/person-year, the incidence rates of stenosis were 0.45 (95% CI 0.26-0.73) versus 0.92 (95% CI 0.80-1.06) (P = 0.005) cases/person-year and the incidence rates of occlusion/thrombosis were 0.34 (95% CI 0.17-0.59) versus 0.62 (95% CI 0.52-0.74) cases/person-year in the LE group compared to those in the UE group (P = 0.041).

CONCLUSIONS

LE AVG had higher primary patency rate and lower postoperative complication incidence than UE AVG. With the development of interventional technology, both LE AVG and UE AVG exhibited high secondary patency rates. LE AVG can be a reliable and long-term alternative for appropriately selected patients with unusable UE vessels.

Six-year outcomes of a phase II study of human-tissue engineered blood vessels for peripheral arterial bypass

Objective

The human acellular vessel (HAV) was evaluated for surgical bypass in a phase II study. The primary results at 24 months after implantation have been reported, and the patients will be evaluated for ≤10 years.

Methods

In the present report, we have described the 6-year results of a prospective, open-label, single-treatment arm, multicenter study. Patients with advanced peripheral artery disease (PAD) requiring above-the-knee femoropopliteal bypass surgery without available autologous graft options had undergone implantation with the HAV, a bioengineered human tissue replacement blood vessel. The patients who completed the 24-month primary portion of the study will be evaluated for ≤10 years after implantation. The present mid-term analysis was performed at the 6-year milestone (72 months) for patients followed up for 24 to 72 months.

Results

HAVs were implanted in 20 patients at three sites in Poland. Seven patients had discontinued the study before completing the 2-year portion of the study: four after graft occlusion had occurred and three who had died of causes deemed unrelated to the conduit, with the HAV reported as functional at their last visit. The primary results at 24 months showed primary, primary assisted, and secondary patency rates of 58%, 58%, and 74%, respectively. One vessel had developed a pseudoaneurysm deemed possibly iatrogenic; no other signs of structural failure were reported. No rejections or infections of the HAV occurred, and no patient had required amputation of the implanted limb. Of the 20 patients, 13 had completed the primary portion of the study; however, 1 patient had died shortly after 24 months. Of the remaining 12 patients, 3 died of causes unrelated to the HAV. One patient had required thrombectomy twice, with secondary patency achieved. No other interventions were recorded between 24 and 72 months. At 72 months, five patients had a patent HAV, including four patients with primary patency. For the entire study population from day 1 to month 72, the overall primary, primary assisted, and secondary patency rate estimated using Kaplan-Meier analysis was 44%, 45%, and 60% respectively, with censoring for death. No patient had experienced rejection or infection of the HAV, and no patient had required amputation of the implanted limb.

Conclusions

The infection-resistant, off-the-shelf HAV could provide a durable alternative conduit in the arterial circuit setting to restore the lower extremity blood supply in patients with PAD, with remodeling into the recipient's own vessel over time. The HAV is currently being evaluated in seven clinical trials to treat PAD, vascular trauma, and as a hemodialysis access conduit.

Successful Use of Arteriovenous Graft for Hemodialysis Access After Left Ventricular Assist Device Placement

Kidney replacement therapy is required in up to one-third of patients after left ventricular assist device (LVAD) placement. A subset of these patients requires long-term maintenance hemodialysis and therefore needs durable vascular access but the ideal access in such patients has not been established. We present a series of 3 patients in whom arteriovenous grafts (AVGs) were successfully used for long-term kidney replacement therapy after LVAD placement. The maximum time from AVG placement to first successful AVG use was 40 days, and the longest AVG use duration was more than 2 years. 2 patients required AVG excision due to infection but both had successful placement of a second AVG. Total time on kidney replacement therapy was 993, 1,055, and 956 days for the 3 cases, of which dialysis catheter use was required for only 23%, 6.5%, and 27%, respectively. These cases suggest that AVG placement is a viable option for dialysis access in patients with LVADs.

Clinical characteristics and outcomes of infective endocarditis: impact of haemodialysis status, especially vascular access infection on short-term mortality

BACKGROUND

Patients on haemodialysis (HD) are at high risk of infective endocarditis (IE). Research comparing the microbiological features as well as clinical characteristics and outcomes of HD and non-HD patients with IE is limited. Specifically, no data focussed on vascular access infections (VAIs) have been reported.

METHODS

The medical records of patients with IE were retrospectively reviewed from January 2010 to February 2020 in a referral hospital in Korea. Those with definite or possible IE by modified Duke criteria were included in the study. The clinical characteristics, microbiological features, echocardiographic findings and outcomes of the patients were analysed.

RESULTS

Of the 80 patients with IE, 34 had undergone HD and 46 had not. HD patients with IE had a higher in-hospital mortality rate (50% vs. 17.4%, p = .004) than non-HD patients. In multivariable stepwise Cox proportional hazards regression analysis, HD (hazard ratio = 2.633; 95% confidential interval: 1.053-6.582; p = .038) was predictors of 60-day mortality in IE patients. In HD patients, the presence of VAI was associated with a high in-hospital mortality rate (70.59% vs. 29.41%, p = .039) and all of the patients with VAIs (100%) had methicillin-resistant S. aureus (MRSA) as a causative pathogen.

CONCLUSIONS

HD patients with IE showed high in-hospital mortality. HD, high C-reactive protein levels and lower left ventricular ejection fraction were predictors of 60-day mortality in IE patients. In particular, HD patients with VAIs had higher mortality rates and MRSA should be considered as the causative microorganism.

Long-term outcomes of transposed femoral vein arteriovenous fistula for abandoned upper extremity dialysis access

BACKGROUND

The number and longevity of patients with end-stage renal disease requiring dialysis access have continued to increase, leading to challenging situations, including exhausted upper extremity access and severe central venous stenosis. This has led to an increase in the use of alternative access sites, including the lower extremities. The transposed femoral vein arteriovenous fistula for dialysis access is a previously described alternative, although limited data are available on its long-term patency.

METHODS

Patients treated with a transposed femoral vein fistula were retrospectively reviewed. A transposed femoral vein fistula was created by harvesting the femoral vein and transposing it to the distal superficial femoral artery at the level of the adductor canal. The demographic information, perioperative characteristics, complications, and long-term outcomes were recorded and analyzed.

RESULTS

A total of 21 patients had undergone transposed femoral vein fistula for dialysis access after an average of 5.3 ± 2.8 failed dialysis access procedures and a duration of 6.1 ± 4.9 years from the initiation of dialysis. The average age at the procedure was 53.5 ± 12.8 years. Ten patients (47.6%) had a history of diabetes mellitus and nine (42.9%) had a history of coronary artery disease. Technical success was achieved in 100% of cases, and 16 patients (76.2%) were discharged with anticoagulation therapy. The primary patency at 1, 3, and 5 years was 93%, 74%, and 74%, respectively. The secondary patency at 1, 3, and 5 years was 100%, 89%, and 89%, respectively. Two patients had compartment syndrome requiring fasciotomy, and six patients experienced wound complications.

CONCLUSIONS

Transposed femoral vein fistula for dialysis access is a viable alternative for patients with an exhausted upper extremity access, with good long-term patency.

Single Asian Center Experience Using the Flixene™ Early Cannulation Graft for Hemodialysis Access Creation

BACKGROUND

The aim of this study was to review the efficacy of the Flixene™ (Atrium™, Hudson, NH, USA) hemodialysis arterio-venous graft (AVG) in a multiethnic Asian cohort of patients with end-stage renal failure (ESRF). Primary outcome was graft primary patency rate and secondary end points included graft usability, time to cannulation, reinterventions required for access salvage, complications, and patient mortality.

METHODS

Single-center, single-arm, multi-investigator nonrandomized retrospective study. Patients with ESRF who underwent Flixene™ graft implantation over a two-year period (January 2017 - December 2018) were included to allow at least one-year follow-up. Demographics, procedural and follow-up data were collected from the hospital electronic medical records.

RESULTS

About 48 patients (49 AVG) were included. There were 24 (50%) men; mean age 63.7 (IQR 58.2-71.3) years. Technical success rate was 45/49 (91.8%); 4/49 (8.2%) AVG created did not reach cannulation. 11/49 (22.4%) and 28/49 (57.1%) achieved cannulation within 1 and 2 weeks, respectively. 6- and 12- month primary patencies were 33.5% and 19.6%, respectively. Primary-assisted patency rates were 46.6% and 29.6% at the same time intervals. Secondary patency rate was 77.6% and 63.9% at 6 and 12 months, respectively. There were 6 (12.2%) graft infections requiring explant and one-year mortality was 14%.

CONCLUSIONS

Our experience with the Flixene™ early cannulation graft is comparable with other AVGs in terms of patency and infection rates. However, early cannulation rates are lower than in other case series.

The utility of portable negative pressure wound therapy in the management of prosthetic dialysis arteriovenous graft infection

The management of prosthetic dialysis arteriovenous graft infection comprises antibiotic treatment and total or partial excision of infected grafts for infectious source control. Partial excision with graft bypass is an important graft preservation strategy for localized infection but carries a higher reinfection risk. Here, we report a case of prosthetic graft infection that was successfully treated with partial excision, a graft bypass procedure, and a portable negative pressure wound therapy system, PICO, applied to the open wound postoperatively. The combined approach may be a useful strategy that decreases reinfection risk, shortens the length of hospital stay, and preserves graft patency.

KDOQI Clinical Practice Guideline for Vascular Access: 2019 Update

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

Current Concepts in Hemodialysis Vascular Access Infections

Infection-related causes are second only to cardiovascular events for mortality among end-stage renal disease patients. This review will provide an overview of hemodialysis catheter-, graft-, and fistula-related infections with emphasis on diagnosis and management in specific settings. Use of catheters at the initiation of dialysis has remained unchanged at 80%. Of all access-related bloodstream infections (BSIs), 70% occur in patients with catheters. The risk factors for BSIs in tunneled, cuffed catheters include the duration of the catheter, past catheter-related bacteremia, left-sided internal jugular vein catheters, hypoalbuminemia, and immunosuppression. Surprisingly, human immunodeficiency virus infection has not been associated with a higher risk of catheter-related bacteremia. Catheter-related bloodstream infection is a clinical definition that requires specific laboratory testing to identify the catheter as the source of the BSI. A central line-associated bloodstream infection is a primary BSI in a patient who had a catheter within the 48-h period before the development of the BSI with no other identifiable source. Guidewire exchange of catheter is a viable alternative in select patients to aid in preserving venous access sites. Catheter lock therapy can decrease infectious complications and mortality. Arteriovenous graft infections are prevalent with significant morbidity. Studies evaluating the impact of stent use in infection risks of the arteriovenous graft are sorely needed.

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.

A rare fatal complication of bleeding immediately following polytetrafluoroethylene arteriovenous grafting in a lady with Goodpasture syndrome

We report a 28-year-old female with no history of allergies and recent onset of Goodpasture syndrome who developed life-threatening bleeding immediately after placement of a polytetrafluoroethylene (PTFE) graft as an access for hemodialysis in the left upper limb by an experienced vascular surgeon. In spite of transfusing fresh frozen plasma, packed cells and cryoprecipitate, her prothrombin time (PT), activated partial thromboplastin time and international normalized ratio became progressively worse which were normal at the beginning of the surgery. She had profound hypotension and succumbed within 8 hours. We suspect a rare phenomenon of the interaction of her blood with the PTFE graft causing activation of bleeding and coagulation factors leading to disseminated intravascular coagulation (DIC).

Spanish Clinical Guidelines on Vascular Access for Haemodialysis

Vascular access for haemodialysis is key in renal patients both due to its associated morbidity and mortality and due to its impact on quality of life. The process, from the creation and maintenance of vascular access to the treatment of its complications, represents a challenge when it comes to decision-making, due to the complexity of the existing disease and the diversity of the specialities involved. With a view to finding a common approach, the Spanish Multidisciplinary Group on Vascular Access (GEMAV), which includes experts from the five scientific societies involved (nephrology [S.E.N.], vascular surgery [SEACV], vascular and interventional radiology [SERAM-SERVEI], infectious diseases [SEIMC] and nephrology nursing [SEDEN]), along with the methodological support of the Cochrane Center, has updated the Guidelines on Vascular Access for Haemodialysis, published in 2005. These guidelines maintain a similar structure, in that they review the evidence without compromising the educational aspects. However, on one hand, they provide an update to methodology development following the guidelines of the GRADE system in order to translate this systematic review of evidence into recommendations that facilitate decision-making in routine clinical practice, and, on the other hand, the guidelines establish quality indicators which make it possible to monitor the quality of healthcare.

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.

Thigh arteriovenous grafts. Quantitative comparison with alternative options: A meta-analysis

Thigh arteriovenous grafts are required in a number of patients with exhausted upper extremity veins and comprise 1%-5% of the total access procedures performed. Alternative autogenous lower extremity options are the rarely used sapheno-tibial arteriovenous fistulae, the saphenous vein transpositions, and the femoral vein transpositions. The latter have proven to be the most durable lower limb access procedures, with low infection rates and their primary patency rates ranged from 74% up to 87% at 2 years. Synthetic thigh grafts are suitable for patients who are not good candidates for any upper limb or any autogenous lower limb access and their secondary patency rates ranged from 54% up to 83% at 2 years. Thigh grafts often get infected and their average weighed infection rate in 920 such grafts included in eight large series was 22.9%. A literature search was performed to evaluate thigh grafts compared with alternative options using meta-analysis. Lower limb accesses were found superior compared to HeRO^® device regarding 1-year primary failure rate (odds ratio = 0.28, confidence interval = 0.09-0.88, p = 0.03) and additionally autogenous lower limb accesses were found superior compared to thigh grafts regarding the 1-year primary failure rate (odds ratio = 6.54, confidence interval = 2.29-18.72, p = 0.0005).

How to treat arteriovenous graft infection: total versus partial graft excision

Introduction:

Arteriovenous graft (AVG) infection can result in life-threatening sepsis and loss of vascular access. A retrospective study was performed to establish an appropriate treatment strategy for AVG infection.

Methods:

A total of 50 cases of AVG infection were treated between January 2005 and June 2016. The surgical methods used were total graft excision (TGE) (n = 34), or partial graft excision (PGE) with interposition graft (n = 16).

Results:

Infection was noted at a puncture site (n = 22), a prior incision for surgery or endovascular therapy (n = 20), and abandoned (currently unused) grafts (n = 5). Infection occurred within 1 month after AVG creation (n = 1), or any intervention (n = 14), and more than 1 month after creation or intervention (n = 35). Simultaneous remote infection was identified in 7 patients, 2 of whom underwent an operation for infective endocarditis and spondylitis. After PGE, 5 patients (5/16, 31.2%) having recurrent infection were treated with further graft excision; however, no patient showed life-threatening complications. After TGE, a central venous catheter (CVC) was inserted and used for a median period of 90 days. Among 34 patients who underwent TGE, new vascular access was created in 18 patients at a median period of 2 months later, and 12 patients continued to use a CVC until last follow-up or death.

Conclusions:

PGE could be a treatment option for AVG infection to achieve both infection eradication and vascular access preservation in selected patients. Because of a higher risk of recurrent infection, sufficient surgical removal and careful postoperative management are warranted.

Susceptibility of ePTFE vascular grafts and bioengineered human acellular vessels to infection

BACKGROUND

Synthetic expanded polytetrafluorethylene (ePTFE) grafts are routinely used for vascular repair and reconstruction but prone to sustained bacterial infections. Investigational bioengineered human acellular vessels (HAVs) have shown clinical success and may confer lower susceptibility to infection. Here we directly compared the susceptibility of ePTFE grafts and HAV to bacterial contamination in a preclinical model of infection.

MATERIALS AND METHODS

Sections (1 cm²) of ePTFE (n = 42) or HAV (n = 42) were inserted within bilateral subcutaneous pockets on the dorsum of rats and inoculated with Staphylococcus aureus (10⁷ CFU/0.25 mL) or Escherichia coli (10⁸ CFU/0.25 mL) before wound closure. Two weeks later, the implant sites were scored for abscess formation and explanted materials were halved for quantification of microbial recovery and histological analyses.

RESULTS

The ePTFE implants had significantly higher abscess formation scores for both S. aureus and E. coli inoculations compared to that of HAV. In addition, significantly more bacteria were recovered from explanted ePTFE compared to HAV. Gram staining of explanted tissue sections revealed interstitial bacterial contamination within ePTFE, whereas no bacteria were identified in HAV tissue sections. Numerous CD45⁺ leukocytes, predominantly neutrophils, were found surrounding the ePTFE implants but minimal intact neutrophils were observed within the ePTFE matrix. The host cells surrounding and infiltrating the HAV explants were primarily nonleukocytes (CD45^-).

CONCLUSIONS

In an established animal model of infection, HAV was significantly less susceptible to bacterial colonization and abscess formation than ePTFE. The preclinical findings presented in this manuscript, combined with previously published clinical observations, suggest that bioengineered HAV may exhibit low rates of infection.

Femoral Arteriovenous Grafts for Hemodialysis: Retrospective Comparison With Upper Extremity Grafts and Fistulas

Background:

Femoral arteriovenous grafts are rarely used to provide vascular access for dialysis patients. This is likely due, in part, to historically high rates of graft loss from infection and thrombosis. However, for selected patients who have exhausted all access options in the upper extremity, femoral grafts can provide additional sites for access creation and may be preferred over central venous catheters.

Objective:

We sought to demonstrate that femoral grafts can provide a reliable and safe alternative to central venous catheters for selected patients.

Methods:

A single-center retrospective review in Vancouver, Canada, from April 1, 2008, to March 31, 2012, was conducted. All patients with new arteriovenous access (grafts and fistulas) created during the study period were included in the study population and followed for a minimum of 2 years. Comparisons of patency (primary, secondary, and functional) and complications (infectious and noninfectious) were made between the different access types.

Results:

Thirteen patients with femoral grafts were compared with 22 patients with arm grafts and 384 patients with fistulas. Femoral grafts had higher rates of thrombosis (46% with a thrombotic event) and a higher requirement for interventions (1.3 angioplasties and 0.12 thrombolytic procedures per patient per year). However, compared with arm grafts, femoral grafts had superior secondary and functional patency. No difference in patency was seen when comparing femoral grafts with upper extremity fistulas. Only 2 patients with femoral grafts required antibiotics for infection, and no grafts were lost to infection.

Conclusions:

For patients with limited access options remaining, femoral grafts may provide an additional form of vascular access before resorting to catheter use. Our study shows that with appropriate patient selection, femoral grafts have low infection rates and patency that is comparable with other access types.

The Clinical and Economic Effect of Vascular Access Selection in Patients Initiating Hemodialysis with a Catheter

Patients in the United States frequently initiate hemodialysis with a central venous catheter (CVC) and subsequently undergo placement of a new arteriovenous fistula (AVF) or arteriovenous graft (AVG). Little is known about the clinical and economic effects of initial vascular access choice. We identified 479 patients starting hemodialysis with a CVC at a large medical center (during 2004-2012) who subsequently had an AVF (n=295) or AVG (n=105) placed or no arteriovenous access (CVC group, n=71). Compared with patients receiving an AVG, those receiving an AVF had more frequent surgical access procedures per year (1.01 [95% confidence interval, 0.95 to 1.08] versus 0.62 [95% confidence interval, 0.55 to 0.70]; P<0.001) but a similar frequency of percutaneous access procedures per year. Patients receiving an AVF had a higher median annual cost (interquartile range) of surgical access procedures than those receiving an AVG ($4857 [$2523-$8835] versus $2819 [$1411-$4274]; P<0.001), whereas the annual cost of percutaneous access procedures was similar in both groups. The AVF group had a higher median overall annual access-related cost than the AVG group ($10,642 [$5406-$19,878] versus $6810 [$3718-$13,651]; P=0.001) after controlling for patient age, sex, race, and diabetes. The CVC group had the highest median annual overall access-related cost ($28,709 [$11,793-$66,917]; P<0.001), largely attributable to the high frequency of hospitalizations due to catheter-related bacteremia. In conclusion, among patients initiating hemodialysis with a CVC, the annual cost of access-related procedures and complications is higher in patients who initially receive an AVF versus an AVG.

Long Term Outcomes of Arteriovenous Grafts for Hemodialysis in Lower Extremities

Purpose:

The lower extremity has received its fair share of attention as a vascular access site in patients who have exhausted their upper arm vessels. However, experiences with lower extremity arteriovenous grafts (AVGs) have so far been disappointing because of high infection rates and severe limb ischemia. We report our experience with hemodialysis access from the lower extremity.

Materials and Methods:

A retrospective review of 60 lower extremity AVGs created between January 2003 and December 2011 was performed. Age, sex, etiology of end-stage renal disease and complications were tabulated. Primary and secondary patency rates were determined.

Results:

The average age of the study population was 56 years and 38 patients were female. Renal failure was associated with hypertension in 40 (66.7%) patients, diabetes in 28 (46.7%) patients and cardiovascular disease in 9 (15.0%) patients. The follow-up period was 8–108 months. Fifty-four patients had bilateral central vein stenosis. Seven (11.7%) patients had primary failure of their AVG. There was no operation-related death. Primary and secondary patency rates were: 66% and 90% at 1 year, 40% and 90% at 2 years, 27% and 87% at 3 years, and 18% and 87% at 5 years, respectively. There were 105 postoperative complications that developed in 67 patients. Postoperative complications were: thrombosis (30), proximal vein stenosis (56), infection (9), bleeding with hematoma (1), perigraft seroma (3), steal syndrome (2), and pseudoaneurysm (4).

Conclusion:

A lower extremity AVG seems to be a viable option in patients with unusable upper extremity veins.

A Rare Case of Fatal Endocarditis and Sepsis Caused by Pseudomonas aeruginosa in a Patient with Chronic Renal Failure

Nosocomial catheter-related and Arteriovenous fistula (AV)-related infections are significant concern in patients undergoing haemodialysis. These infections are associated with multiple complications as well as mortality and demands immediate and appropriate management. While coagulase-negative staphylococci, S.aureus, and Escherichia coli are the most common causes of catheter-related infections in haemodialysis patients, such infections caused by Pseudomonas aeruginosa are relatively rare. Here, we present an unusual case of 36-year-old male patient with chronic renal failure, who developed endocarditis and sepsis from Pseudomonas aeruginosa infection of the left hand arteriovenous fistula. The bacteraemia in the present case caused multiple complications including dry gangrene of bilateral lower limbs, stroke, endophthalmitis, left brachial artery thrombosis and vegetations on the interventricular septum and aortic wall. Despite antibiotic treatment, the patient suffered a cardiac arrest and could not be revived.

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.

Prosthetic Arteriovenous Graft Contact Dermatitis Masquerading as an Arteriovenous Graft Infection in a Hemodialysis Patient

Prosthetic arteriovenous (AV) graft is the second most common vascular access of choice in hemodialysis patients. Rare complications of such grafts are increasingly seen due to rising population of patients on hemodialysis. Infections and thrombosis are the most common complications. Though metallic implants are known to cause hypersensitivity skin reactions, prosthetic AV grafts are rarely known to cause such kind of reactions due to inert nature of materials used in their preparation. We present a case of 54-year-old male who developed contact dermatitis after AV graft creation which was mistreated initially as infection.

We Underutilize the Leg Graft

Once hemodialysis patients have exhausted all option for a permanent vascular access in both upper extremities, they are often relegated at many dialysis centers to permanent catheter dependence with all its attendant complications, including infections, frequent dysfunction, and central vein stenosis. This commentary makes the case that thigh grafts are a far superior alternative to dialysis catheters in many of these patients. Technical graft failure may occur in some patients due to severe femoral artery calcification, but screening for calcification by ultrasound or computerized tomography can reduce the likelihood of a technical failure. Placement of a thigh graft may lead to critical lower extremity ischemia, but preoperative screening for peripheral vascular disease should minimize this possibility. Thigh grafts have comparable secondary patency to that obtained with upper extremity grafts. Finally, although the risk of infection is somewhat higher for thigh grafts than upper extremity grafts, it is still much lower than the risk of catheter-related bacteremia. In summary, thigh grafts should be used much more frequently in patients without an option for an upper extremity access.

Operative and perioperative management of infected arteriovenous grafts

Vascular graft infections are a particularly troublesome complication for dialysis patients, many of whom are in an already immunocompromised state. The objective of this review is to detail the risk factors, etiology, diagnosis, perioperative and operative management of vascular graft infections.

Use of biosynthetic grafts (Omniflow II) for high infection risk haemodialysis vascular access

PURPOSE

Infective complications of patients requiring insertion of arteriovenous grafts for hemodialysis remain a challenge. In particular, patients who have exhausted autologous options and have had recent infective complications relating to alternative dialysis modalities such as peritonitis or central venous catheter-associated bacteremia can pose a significant dilemma. We present a series of challenging cases that represent examples of the use of biosynthetic grafts in patients with on-going infective risks. A review of available literature for the use of the Omniflow II graft in dialysis access is included.

METHODS

Electronic databases were searched for studies assessing the use of the Omniflow II graft for dialysis in accordance with PRISMA published up to 31st March 2014. The primary outcomes for this study were 1-year primary and secondary patency rates. Secondary outcomes were rates of infection and aneurysmal degeneration.

RESULTS

Three cases are described that were considered at high risk of infection and all successfully managed with the Omniflow II arteriovenous graft (AVG). None showed signs of infection and all grafts were patent at three months' follow-up. On review of the literature and following strict criteria, four studies were included with a total of 236 procedures. We found that the one-year primary patency rate for Omniflow II AVGs was 60.1% (53.6-66.5) with a secondary patency rate of 82.1% (76.7-86.9). Infection rates are reported at 0% to 5.7%, with aneurysmal rates ranging between 0% and 6.8%.

CONCLUSIONS

This small series reports on the successful use of the Omniflow II graft in patients with high risk of infection and, whilst limited in its size and scientific design, it does support the limited existing literature for the potential benefits of the biosynthetic approach where concerns regarding infective complications of synthetic material exist.

Risk Evaluation of Immediate Surgical Failure During Thigh Hemodialysis Graft Placement by Sonographic Screening

OBJECTIVES

The purpose of this study was to determine whether preoperative sonographic evaluation of vascular diameters and calcification identifies patients at risk for immediate technical failure of thigh hemodialysis grafts.

METHODS

A retrospective analysis of 143 chronic hemodialysis patients who underwent thigh graft placement was performed. All patients underwent preoperative sonography to assess arterial and venous waveforms and vascular diameters. The degree of arterial calcification was assessed retrospectively. Patient characteristics and graft outcomes were examined. Statistical analyses were performed, with P< .05 considered clinically significant.

RESULTS

Sonography identified no or mild arterial calcification in 113 of 143 patients (79%) and moderate to severe calcification in 30 of 143 patients (21%). Primary surgical technical failure occurred in 23% of patients (7 of 30) with moderate to severe calcification, compared to 3.5% (4 of 113) of those with no or mild calcification (hazard ratio, 6.59; 95% confidence interval, 2.06-21.05; P = .002). Cumulative graft survival (time to permanent failure) was shorter in patients with moderate to severe arterial calcification (3-year graft survival, 37% versus 56%; hazard ratio, 2.32; 95% confidence interval, 1.48-6.69; P= .003) but was not significantly associated with venous (P= .82) or arterial (P = .43) diameters.

CONCLUSIONS

Preoperative sonographic assessment of thigh vessel diameters and calcification can identify patients who may be at risk for immediate technical graft failure and decreased cumulative graft survival. The use of sonography as a screening examination may improve preoperative assessment and surgical planning of hemodialysis thigh grafts.

Current Outcomes and Indications for Cryopreserved Vein Allografts in Hemodialysis Access Surgery

Introduction

Cryopreserved vein allografts (cadaveric vein) have emerged as an option for arteriovenous graft reconstruction; however, indications for their use in hemodialysis access remains to be clearly defined. Observations from our own experience have suggested that cadaveric vein grafts (CVGs) provide good outcomes, particularly in patients with a history of infection, recurrent access failure and advanced age.

Methods

This is a 10-year retrospective study. Primary outcomes were ( 1 ) to identify characteristics specific to this patient population and ( 2 ) to better define indications for use of cadaveric vein in hemodialysis access creation.

Results

Indications for creation of CVGs included patient history of either active or recent infection (41.5%), recurrent access failure (43.4%) or surgeon preference secondary to patients’ advanced age (9.4%). Observed primary patency rates were 84.9% (30 days), 22.6% (1 year) and 16.0% (2 years). Secondary patency was 93.4% (30 days), 66.0% (1 year) and 52.8% (2 years). Patient death was the highest cause of graft abandonment (52.9%) followed by thrombosis (19.1%), infection (11.7%) and rupture (11.7%). CVG patency at the time of patient death was 83.7%.

Conclusions

The rates of both primary and secondary patency in CVGs are highly comparable to the reported patency rates of polytetrafluoroethylene (PTFE) grafts and allow for lifelong maintenance of dialysis access. Our observed outcome suggests that CVGs should be considered for patients needing vascular access in the presence of infection. CVGs may likewise be viable alternatives to PTFE grafts in the elderly and patients with limited access options.

Immediate access arteriovenous grafts versus tunnelled central venous catheters: study protocol for a randomised controlled trial

BACKGROUND

Autologous arteriovenous fistulae (AVF) are the optimal form of vascular access for haemodialysis. AVFs typically require 6 to 8 weeks to "mature" from the time of surgery before they can be cannulated. Patients with end-stage renal disease needing urgent vascular access therefore traditionally require insertion of a tunnelled central venous catheter (TCVC). TCVCs are associated with high infection rates and central venous stenosis. Early cannulation synthetic arteriovenous grafts (ecAVG) provide a novel alternative to TCVCs, permitting rapid access to the bloodstream and immediate needling for haemodialysis. Published rates of infection in small series are low. The aim of this study is to compare whether TCVC ± AVF or ecAVG ± AVF provide a better strategy for managing patients requiring immediate vascular access for haemodialysis.

METHODS/DESIGN

This is a prospective randomised controlled trial comparing the strategy of TCVC ± AVF to ecAVG ± AVF. Patients requiring urgent vascular access will receive a study information sheet and written consent will be obtained. Patients will be randomised to receive either: (i) TCVC (and native AVF if this is anatomically possible) or (ii) ecAVG (± AVF). 118 patients will be recruited. The primary outcome is systemic bacteraemia at 6 months. Secondary outcomes include culture-proven bacteraemia rates at 1 year and 2 years; primary and secondary patency rates at 3, 6, 12 and 24 months; stenoses; re-intervention rates; re-admission rate; mortality and quality of life. Additionally, treatment delays, impact on service provision and cost-effectiveness will be evaluated.

DISCUSSION

This is the first randomised controlled trial comparing TCVC to ecAVG for patients requiring urgent vascular access for haemodialysis. The complications of TCVC are considered an unfortunate necessity in patients requiring urgent haemodialysis who do not have autologous vascular access. If this study demonstrates that ecAVGs provide a safe and practical alternative to TCVC, this could instigate a paradigm shift in nephrology thinking and access planning.

TRIAL REGISTRATION

This study has been approved by the West of Scotland Research Ethics Committee 4 (reference no. 13/WS/0087, 28 August 2013) and is registered with the International Standard Randomised Controlled Trial Number Register (reference no. ISRCTN80588541 , 27 May 2014).

Bilateral Central Vein Stenosis: Options for Dialysis Access and Renal Replacement Therapy when all upper Extremity Access Possibilities have been Lost

Purpose

Patients with bilateral central vein stenosis present a unique challenge: treatment options are limited, largely unproven and associated with reputedly poor outcomes. Our aim was to compare patency rates of different access and renal replacement treatment (RRT) modalities in patients with bilateral central vein stenosis/occlusion.

Material and methods

Data on all patients presenting to a tertiary referral vascular access centre with end-stage vascular access (defined by bilateral central vein stenosis/occlusion with loss of upper limb access) over a 5-year period were included. 3, 6 and 12-month patencies of translumbar catheters (TLs), tunnelled femoral catheters (Fem), native long saphenous vein loops (SV), prosthetic mid-thigh loop grafts (ThGr), peritoneal dialysis (PD), and expedited donation after cardiac death (DCD) cadaveric renal transplants (Tx) via local allocation policies were compared using log-rank test. Kaplan–Meier survival analysis was used to estimate long-term access survival.

Results

One hundred forty-six vascular access modalities were attempted in 62 patients (62 Fem, 25 TL, 15 SV, 25 ThGr, 8 PD, 11 Tx). Median follow-up was 876±57 days. Three, 6 and 12-month primary-assisted patencies for each modality were as follows: Fem: 75.4%, 60% and 28%; TL: 88%, 65% and 50%; SV: 87.5%, 60% and 44.6%; ThGr: 64%, 38% and 23.5%; PD: 62.5%, 62.5% and 50%; Tx: 72.7%, 72.7% and 72.7%. SV had better secondary patency at 900 days (76.9%) than ThGr (49.2%) or Fem (35.8%) (p<0.01). No patients died as a result of loss of access.

Conclusion

Patients with bilateral central vein stenosis often require more than one vascular access modality to achieve a “personal access solution.” Native long saphenous vein loops provided the best long-term patency. Expedited renal transplantation with priority local allocation of DCD organs to patients with precarious vascular access provides a potential solution to this difficult problem.

Early Cannulation Prosthetic Graft (Acuseal™) for Arteriovenous Access: A useful option to provide a Personal Vascular access Solution

Purpose

Early cannulation arteriovenous grafts (ecAVGs), such as the GORE® Acuseal™, have “low bleed” properties permitting cannulation within 24 hours of insertion. They may provide an alternative to tunneled central venous catheters (and associated line complications) in patients requiring urgent vascular access.

Methods

We present our early experience of 37 patients treated with the GORE® Acuseal™ ecAVG.

Results

A total of 11 upper limb, 24 lower limb and 2 complex graft procedures were performed. Indications for ecAVG were as follows: bridge to transplantation (21.6%); bridge to arteriovenous fistula (AVF) maturation (8.1%); AVF salvage (8.1%); no native options (67.6%, including 17 patients with bilateral central vein stenosis); 36 AVGs (97.3%) were successfully cannulated. Mean time to first cannulation: 30.4±23.4 hours (range: 2–192). Primary and secondary patency rates at 3, 6 and 12 months were 64.9%, 48.6%, 32.4% and 70.2%, 59.4%, 40.5% respectively. The systemic bacteremia rate was 0.2 per 1,000 access days. There was one perioperative death. Other complications included hematoma at cannulation sites (n=9), pseudoaneurysm (n=3) and local infection at graft site (n=6). A total of 26 of 37 patients (70.6%) achieved a “personal vascular access solution”: bridge to transplantation (n=8), bridge to functioning AVF/interposition AVG (n=5), maintenance hemodialysis via ecAVG (n=13); death with functioning AVG (n=1).

Conclusions

Early experience with the GORE® Acuseal™ is encouraging. Patency and bacteremia rates are at least comparable to standard polytetrafluoroethylene grafts. ecAVGs have permitted cannulation within 24 hours of insertion and line avoidance in the majority of patients. Nearly three-quarters of patients achieved a definitive “personal vascular access solution” from their ecAVG.

The end stage of dialysis access: femoral graft or HeRO vascular access device

BACKGROUND

Maintaining and establishing vascular access in end-stage renal disease (ESRD) patients is complicated when they are poor candidates for traditional upper extremity access. Our objective was to compare our experience with 2 alternative dialysis accesses, the femoral arteriovenous graft (fAVG) and the Hemodialysis Reliable Outflow (HeRO), in patients with limited remaining options.

METHODS

A single institution, retrospective review of ESRD patients with fAVG or HeRO placed between May 2009 and February 2013 was performed. Adult patients were selected by reviewing all arteriovenous grafts placed at a single institution. Patient demographics, medical history, access characteristics, and outcomes were recorded from both institutional and dialysis center databases. Data were evaluated using Fisher's exact test, unpaired t-test for continuous variables, log-rank test, and univariate analysis.

RESULTS

A total of 56 accesses in 43 unique patients met these criteria: 35 fAVG and 21 HeRO; with 1 HeRO patient lost immediately to follow-up. Clinical variables were similar except the HeRO group had more diabetic patients (60% HeRO, 22.9% fAVG; P = 0.01). The average number of years on hemodialysis was 7.0 ± 1.0 for fAVG and 5.7 ± 0.9 for HeRO (P = 0.41). Primary patency was 40.5%, 18.7%, and 14.9% for fAVG and 29.0%, 29.0%, and 0% for HeRO at 6 months, 12 months, and 2 years (P = 0.67), respectively. Assisted primary patency was also similar, with 43.8%, 29.4%, and 13.8% for fAVG and 34.8%, 34.8%, and 17.4% for HeRO at 6 months, 12 months, and 2 years (P = 0.81), respectively. Secondary patency was 62.6%, 50.6%, 19.3% for fAVG and 68.0%, 53.5%, 38.3% for HeRO at 6 months, 12 months, and 2 years (P = 0.69), respectively. Average number of interventions to maintain patency for fAVG was 1.1 ± 1.47 and 1.65 ± 2.52 for HeRO (P = 0.35). Infectious complications occurred in 29% of fAVG and 15% of HeRO (P = 0.33).

CONCLUSIONS

Patients who received either fAVG or HeRO experience poor access patency. ESRD patients who receive either of these procedures appear to be at the end stage of available access options.

Lower limb access

Lower limb vascular access is used as an access site in patients in whom all upper limb possibilities for arteriovenous access creation are exhausted or with bilateral upper limb central vein occlusions. Autologous arteriovenous fistulae (AVF) using the greater saphenous vein have disappointing results apart from the isolated success. Autologous AVF using the femoral vein transposition have good results both in terms of long-term patency and are associated with a 10-fold reduction in infection risk compared with arteriovenous grafts (AVGs). However, a femoral vein transposition is a major undertaking and is associated with an increased risk of ischaemic complications. It is not a good option for patients with established peripheral arterial disease, but may be a good alternative for the younger patient with a high infection risk. The type of lower-extremity vascular access should be carefully tailored to the individual patient.

Long-term outcomes of arteriovenous thigh grafts in hemodialysis patients: a comparison with tunneled dialysis catheters

BACKGROUND AND OBJECTIVE

Arteriovenous thigh grafts are a potential vascular access option in hemodialysis patients who have exhausted all upper-limb sites. This study compared the outcomes of thigh grafts with outcomes obtained with dialysis catheters.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A prospective vascular access database was queried to identify 209 thigh grafts placed from January 1, 2003, to June 30, 2011. The following were calculated: secondary graft survival (from graft creation to permanent failure), assisted primary graft survival (from graft creation to first thrombosis), and infection-free graft survival (from graft creation to first graft infection). Graft outcomes were compared with those observed with 472 tunneled internal jugular dialysis catheters.

RESULTS

The median duration of patient follow-up was 340 days for grafts and 91 days for catheters. The surgical technical failure rate of thigh grafts was 8.1% and was higher in patients with vascular disease (hazard ratio [HR], 2.94; 95% confidence interval [CI], 1.07-8.04; P=0.03). Secondary and assisted primary graft survival rates at 1, 2, and 5 years were 62%, 54%, and 38% and 38%, 27%, and 17%, respectively. Infection-free graft survival rates at 1, 2, and 5 years were 79%, 73%, and 61%. Secondary survival was much worse for dialysis catheters than thigh grafts (HR, 4.44; 95% CI, 3.65-5.22; P<0.001). Likewise, infection-free survival was far worse for catheters than for thigh grafts (HR, 3.77; 95% CI, 2.80-4.82; P<0.001).

CONCLUSIONS

Thigh grafts are a viable vascular option in patients who have exhausted upper-extremity options. Outcomes with thigh grafts are superior to those obtained with dialysis catheters.