Maintaining vascular access: the management of hemodialysis arteriovenous grafts

Anticoagulation Therapy is Associated with Increased Access-related Wound Infections after Hemodialysis Access Creation

BACKGROUND

The effect of anticoagulation therapy (AC) on hemodialysis access patency and related complications is not well defined. Patients on long-term or chronic AC due to their underlying comorbid conditions may be particularly susceptible to access-related bleeding and complications from repetitive cannulation. Our goal is to assess the effect of anticoagulation therapy on outcomes after access creation.

METHODS

The Vascular Quality Initiative (VQI) database was queried for patients undergoing arteriovenous fistula (AVF) or graft (AVG) placement, from 2011 to 2019. Only patients with data on post-procedural AC status were included. Anticoagulation use was defined as patients on warfarin, dabigatran, or rivaroxaban after access creation at postoperative follow up. Demographic and procedural details were analyzed. Wound infection and patency rates at six months were assessed. Binomial logistic regression analysis was performed to assess the association of anticoagulation use with these outcomes.

RESULTS

A total of 27,757 patients underwent access creation, with the majority undergoing AVF creation (78.8%). The average age was 61.4 years and 55.3% were male. 12.9% of patients were on postoperative AC. The wound infection rate was 2.3- 3.8% in the no AC and AC cohorts, respectively (P < 0.001). At six months follow-up, patency was 85.7- 84.3% in the no AC and AC cohorts, respectively (P = 0.044). Expectedly, grafts had lower patency rates compared to AVF; those within the no AC cohort had a patency of 83.0% compared to 81.2 % in those on AC (P = 0.106). On multivariable analysis, anticoagulation use was associated with a higher risk of wound infections (odds ratio [OR] 1.513, 95% confidence interval [CI] 1.160-1.973, P = 0.002). AC use did not significantly affect access patency.

CONCLUSION

Anticoagulation therapy was associated with a higher rate of wound infections but did not affect short-term access patency within six-months. These patients warrant close surveillance of their access for signs of infection. Furthermore, long-term implications of anticoagulation needs further evaluation.

Relationship between hemodialysis patients' educational level and arteriovenous fistula patency

OBJECTIVES

Vascular access is a lifeline for the patients who are in need of long-term hemodialysis. Native arteriovenous fistula is the most intensively preferred vascular access method owing to its longevity and convenience of use. Therefore, in this study, we aimed to determine whether there might be a relationship between hemodialysis patients' educational levels and arteriovenous fistula patency.

METHODS

A total of 349 patients who were attending in a chronic hemodialysis program between June 2018 and September 2018 at Bursa Uludağ University, Faculty of Medicine Dialysis Unit and in a private dialysis center in İstanbul were included in this study. The patients were grouped into two: those who have had arteriovenous fistula primary failure at least once and those who have never had arteriovenous fistula primary failure. Educational levels of the patients were classified according to Turkish National Education system (illiterate, primary school graduate, secondary school graduate, high school graduate, and university graduate). Mann-Whitney U and Chi-square tests were performed for statistical analyses. Risk factors were determined by applying backward binary logistic regression analysis.

RESULTS

A total of 349 patients, 161 (46.1%) females and 188 (53.9%) males, were examined retrospectively. The median age of the patients was 64 years (range: 18-90 years). Educational level comparison revealed statistically significant difference in terms of fistula patency (p = 0.016). In particular, fistula patency was significantly lower in illiterate, primary, secondary, and high school graduates in comparison with university graduates (p = 0.001, p = 0.015, p = 0.003, and p = 0.018, respectively). When each group of educational level was analyzed separately in terms of fistula patency, it was observed that the higher the educational level was, the lower arteriovenous fistula primary failure rates were.

CONCLUSIONS

In this study, we observed a lower rate of fistula patency in patients with a low level of education. Hence, we are of the opinion that the trainings delivered on arteriovenous fistula care in dialysis centers are required to be shaped in accordance with educational levels of patients.

Quality indicators of vascular access procedures for hemodialysis

Improved quality of surgical procedures can minimize complications, the morbidity and mortality of patients, and in addition decrease costs. Quality indicators in angioaccess surgery are, however, not clearly defined. The aim of this review article is therefore to find the most important factors affecting quality in vascular access procedures. Even though autogenous arteriovenous fistula has been recognized as the best vascular access for hemodialysis, the high percentage of unsuccessful attempts associated with it raises the question about quality assessment in angioaccess procedures. Unfortunately, quality indicators in vascular access surgery are difficult to define and measure. Among those that can be obtained are: the time between the presentation of patients to a vascular access surgeon and the construction of a fistula, the percentage of autogenous fistulas, the percentage of functional fistulas in prevalent and incident hemodialysis patients, the percentage of creation of a functional fistula in the first attempt, and durability of an access. Organizational improvement and educational programs are also necessary at institutions with inferior quality indicators of vascular access care, as even small increase in quality may mean the survival of an individual patient. Quality indicators in angioaccess surgery can also serve as a helpful tool in choosing the best vascular access surgeon or vascular access center. The choice can consequently reflect on increased survival and quality of life in patients needing hemodialysis.

Pull-through technique combined with percutaneous angioplasty for treating high-grade arteriovenous fistula stenosis

PURPOSE

The aim of this study was to investigate the effectiveness of a new pull-through technique through a brachial artery approach combined with angioplasty for the treatment of arteriovenous fistula.

METHODS

In this retrospective study, a total of 56 arteriovenous fistula patients with high-grade stenosis induced by arteriovenous fistula, which was divided into pull-through technique through a brachial artery approach (pull-through group, n = 28) and solely through a venous approach (control group, n = 28), were analyzed. Both groups underwent percutaneous transluminal angioplasty treatments simultaneously.

RESULTS

The success rate of the pull-through group (89.3%, 25 out of 28) was similar to that of the control group (75.0%, 21 out of 28, p = 0.296). Fistula restenosis occurred with time in both groups but no significant differences in the post-operative fistula patency were found between the pull-through and control groups in follow-ups at 3, 6, and 12 months (71.4% vs 67.9%, 57.1% vs 60.7%, and 20.0% vs 30.0%, respectively, p > 0.05). No significant difference in the post-operative patency rate in patients with diabetes, hypertension, or coronary disease was found between the pull-through and control groups in the follow-ups at 3 and 12 months, respectively. The pull-through group had significantly shorter operation times compared with the control group (45 ± 9 min vs 65 ± 15 min, p < 0.001). No surgical complications were reported in the pull-through group in contrast to three cases (11%, 3 out of 28) with puncture hematoma and acute occlusion in the control group.

CONCLUSION

The pull-through technique combined with percutaneous transluminal angioplasty is an effective, safe and lasting option to treat high-grade arteriovenous fistula stenosis in the upper limb.

Quality of Life of Patients Using the Hemodialysis Reliable Outflow (HeRO) Graft in Hemodialysis

End-stage renal disease (ESRD) is one of the most feared consequences of kidney disease. A large number of patients with ESRD require long-term hemodialysis. Vascular access options for hemodialysis include the placement of arteriovenous (AV) fistulas, AV grafts, and tunneled dialysis catheters (TDCs). An alternative to the TDC is the Hemodialysis Reliable Outflow (HeRO; Cryolife Inc., Eden Prairie, MN, USA) Graft. The HeRO Graft has been designed to overcome the development of central venous stenosis or occlusion. The objective is to evaluate the quality of life of patients using the HeRO Graft in end-stage renal disease for hemodialysis. We searched PubMed, Medical Literature Analysis and Retrieval System Online (MEDLINE), Excerpta Medica dataBASE (EMBASE), Cumulative Index to Nursing and Allied Health Literature (CINHAL), Directory of Open Access Journals (DOAJ), Pubpsych, and Google Scholar on October 30, 2018. We included published articles in the English language that used the HeRO Graft for ESRD. The adequacy of dialysis and bacteremia rates proved to be equal to those of conventional AV grafts. It turned out that 2.21 interventions per year were needed to maintain the patency of the HeRO Graft while only 1.17 interventions were needed to maintain the patency of the lower extremity graft. Mortality, ischemia, and infection rates were similar for both groups. The tunneled dialysis catheters have a higher incidence of infection as compared to the HeRO Graft. The initial device and placement costs for the HeRO Graft were higher than those for TDCs but savings from the lower incidence of device complications and longer effective device patency make it cost-effective. Based on the limited evidence, it has been discerned that the HeRO Graft is an optimal option for hemodialysis in patients of ESRD who have exhausted all means of upper extremity access. Though almost similar to the AV grafts in terms of complications and less functional than femoral grafts, it still outclasses them in improving the quality of life of such patients.

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.

Contribution of monoamine oxidases to vascular oxidative stress in patients with end-stage renal disease requiring hemodialysis

Arteriovenous fistula (AVF) is the "lifeline" for patients with end-stage renal disease (ESRD) undergoing hemodialysis. AVF maturation failure is a poorly understood process, one of the contributors being endothelial dysfunction due to oxidative stress. Monoamine oxidases (MAOs) A and B were recently identified as novel sources of vascular oxidative stress. The aim of the present study was to assess the contribution of MAOs to the endothelial dysfunction in patients with ESDR with indication of hemodialysis. Fragments of brachial artery collaterals were harvested from ESRD patients during the surgical procedure aimed at creating the vascular access in the cubital fossa. The effect of increasing concentrations (10, 30, 100 μmol/L) of the irreversible MAO-A inhibitor, clorgyline, and MAO-B inhibitor, selegiline, on endothelial-dependent relaxation (EDR) in response to cumulative doses of acetylcholine was studied in isolated phenylephrine-preconstricted vascular rings. Hydrogen peroxide (H₂O₂) production was assessed using ferrous oxidation xylenol orange assay. We showed that incubation of brachial rings with MAO inhibitors significantly improved EDR and attenuated H₂O₂ generation in patients with ESRD. MAO-related oxidative stress might contribute to the primary dysfunction/non-maturation of the AVF and MAO inhibitors could improve maturation and long-term patency of the vascular access in dialysis patients.

Aortic Arch Calcification as a Predictor of Repeated Arteriovenous Fistula Failure within 1-Year in Hemodialysis Patients

Objectives

The aim of the study was to identify the factors associated with repeated arteriovenous fistula (AVF) failure within 1-year, especially the impact of aortic arch calcification (AAC) on patency of AVF.

Materials and Methods

We retrospectively assessed chest radiography in hemodialysis patients who had undergone initial AVF. The extent of AAC was categorized into four grades (0–3). The association between AAC grade, other clinical variables, and repeated failure of AVF was then analyzed by binary logistic regression analysis.

Results

This study included 284 patients (158 males, mean age 61.7 ± 13.1 years). Patients with higher AAC grade were older, had more frequently diabetes mellitus and cardiovascular disease, had lower diastolic blood pressure, and had higher corrected calcium and lower intact parathyroid hormone levels. In multivariate analysis, the presence of higher AAC grade (odds ratio (95% confidence interval): 2.98 (1.43–6.23); p = 0.004), lower mean corrected calcium (p = 0.017), and mean serum albumin level (p = 0.008) were associated with repeated failure of AVF.

Conclusions

The presence of higher AAC grade, lower mean corrected calcium and mean serum albumin level were independently associated with repeated AVF failure within 1 year in hemodialysis patients.

Are early cannulation arteriovenous grafts (ecAVG) a viable alternative to tunnelled central venous catheters (TCVCs)? An observational "virtual study" and budget impact analysis

BACKGROUND

Early cannulation arteriovenous grafts (ecAVGs) are advocated as an alternative to tunnelled central venous catheters (TCVCs). A real-time observational "virtual study" and budget impact model was performed to evaluate a strategy of ecAVG as a replacement to TCVC as a bridge to definitive access creation.

METHODOLOGY

Data on complications and access-related bed days was collected prospectively for all TCVCs inserted over a six-month period (n = 101). The feasibility and acceptability of an alternative strategy (ecAVGs) was also evaluated. A budget impact model comparing the two strategies was performed. Autologous access in the form of native fistula was the goal wherever possible.

RESULTS

We found 34.7% (n = 35) of TCVCs developed significant complications (including 17 culture-proven bacteraemia and one death from line sepsis). Patients spent an average of 11.9 days/patient/year in hospital as a result of access-related complications. The wait for TCVC insertion delayed discharge in 35 patients (median: 6 days). The ecAVGs were a practical and acceptable alternative to TCVCs in over 80% of patients. Over a 6-month period, total treatment costs per patient wereGBP5882 in the TCVC strategy and GBP4954 in the ecAVG strategy, delivering potential savings ofGBP927 per patient. The ecAVGs had higher procedure and re-intervention costs (GBP3014 vs. GBP1836); however, these were offset by significant reductions in septicaemia treatment costs (GBP1322 vs. GBP2176) and in-patient waiting time bed costs (GBP619 vs. GBP1870).

CONCLUSIONS

Adopting ecAVGs as an alternative to TCVCs in patients requiring immediate access for haemodialysis may provide better individual patient care and deliver cost savings to the hospital.

Aortic Arch Calcification Predicts Patency Loss of Arteriovenous Fistula in End-Stage Renal Disease Patients

Aortic arch calcification (AAC) is recognized as an important cardiovascular risk factor in patients with end-stage renal disease (ESRD). The aim of the study was to evaluate the impact of AAC grade on patency rates of arteriovenous fistula (AVF) in this specific population. The data of 286 ESRD patients who had an initial AVF placed were reviewed. The extent of AAC identified on chest radiography was divided into four grades (0–3). The association between AAC grade, other clinical factors, and primary patency of AVF was then analyzed by Cox proportional hazard analysis. The multivariate analysis demonstrated that the presence of AAC grade 2 (hazard ratio (95% confidence interval): 1.80 (1.15–2.84); p = 0.011) and grade 3 (3.03 (1.88–4.91); p < 0.001), and higher level of intact-parathyroid hormone (p = 0.047) were associated with primary patency loss of AVF. In subgroup analysis, which included AVF created by a surgeon assisted with preoperative vascular mapping, only AAC grade 3 (2.41 (1.45–4.00); p = 0.001), and higher intact-parathyroid hormone (p = 0.025) level were correlated with AVF patency loss. In conclusion, higher AAC grade and intact-parathyroid hormone level predicted primary patency loss of AVF in an ESRD population.

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).

Two-stage Hemodialysis Reliable Outflow (HeRO) graft implantation technique that avoids the use of a femoral bridging dialysis catheter

PURPOSE

The purpose of this study is to report a novel two-stage Hemodialysis Reliable Outflow (HeRO) graft implantation technique that avoids the use of a femoral bridging hemodialysis catheter in internal jugular vein (IJV) catheter-dependent patients with contralateral central venous occlusion.

METHODS

The first stage is to implant the ePTFE component and consists of: 1) performing two to three incisions in the upper arm ipsilateral to the preexisting IJV catheter, 2) tunneling the expanded polytetrafluoroethylene (ePTFE) component through these incision sites, and 3) placing the ePTFE component in the subcutaneous tissue without anastomosing it to the target artery. The preexisting IJV catheter is maintained to provide continuous dialysis access. The second stage is initiated in 4 weeks and includes: 1) thrombectomy and anastomosing the ePTFE component arterial end to the target artery, 2) insertion of the venous outflow component using the preexisting IJV catheter access site, and 3) connecting the venous outflow component to the ePTFE component in the standard fashion.

RESULTS

The HeRO graft was successfully implanted in two stages without using a femoral bridging catheter. Immediate postimplant cannulatabilty was achieved upon completion of the second stage procedure.

CONCLUSION

This novel two-stage HeRO implantation technique is simple, yet allows immediate cannulation upon completion of the second stage procedure while avoiding the need of a femoral bridging catheter in IJV catheter- dependent patients with contralateral central venous occlusion, and thus lowering the risk of infection related to a femoral bridging catheter.

Arteriovenous graft for hemodialysis, graft venous anastomosis closure - current state of knowledge. Minireview

Backround. The use of artificial vascular grafts (arteriovenous graft, AVG) is indicated in patients in hemodialysis programs if the subcutaneous venous bed is exhausted or unsuitable for arteriovenous fistula (AVF) creation. The native fistula should be the hemodialysis access of first choice: AVF has better results in terms of function and potential complications. However, the use of AVG is necessary in some patients. In these patients, extensive clinical examination, color duplex sonography and angiography should be performed prior to indication. The technique of graft implantation requires respect for geometric relations for the graft anastomoses to minimize the formation of intimal hyperplasia mainly on the venous anastomosis. The main complications of AVG are stenosis on the venous anastomosis (VAG), causing closure of graft and graft infection. The cumulative function of AVG is 59-90% in the first year and 50-82% in the second year. Arteriovenous graft stenosis leading to thrombosis is a major cause of complications in patients undergoing hemodialysis. The purpose of this review is to summarise current knowledge of the diagnostics and treatment of graft thrombosis and discuss the issue in combination with relevant publications via Pubmed database.

CONCLUSION

The most frequent cause of failure of AVG for hemodialysis is stenosis and closure by VAG. AVG closure can be addressed surgically, endovascularly (amenable to thrombectomy by radiological or surgical means) and by hybrid performance.

Hybrid Simultaneous Treatment of Thrombosed Prosthetic Grafts for Hemodialysis

Purpose

The aim of the study was to evaluate our experience in the hybrid simultaneous treatment (open and endovascular) of acute thrombosis of prosthetic grafts for hemodialysis.

Methods

Between January 2011 and June 2013, 23 patients with acute thrombosis of a prosthetic graft for hemodialysis were urgently treated with a hybrid simultaneous treatment in order to obtain a prompt restoration of the flow. A new puncture of the graft was scheduled after 24 hours.

Results

Intraoperative technical success was 100% with a completion angiography showing the restored patency of the graft. As adjunctive procedures, in 6 patients (26.1%) locoregional thrombolysis was necessary and in all cases further endovascular manoeuvres (angioplasty/stenting) were immediately performed to solve a significant stenosis of the venous anastomosis/first tract of the vein. At 24 hours when the first puncture was done, three grafts were occluded resulting in a primary patency of 87%. During the follow-up (mean duration 5.6 months) four reocclusions occurred. In-stent restenosis occurred in all patients undergone stenting. At 1 year the rates of primary patency, primary assisted patency and secondary patency were 58.7%, 78.3% and 87%, respectively.

Conclusions

In our series the combined simultaneous hybrid approach in urgency maximizes the use of different available techniques, which appeared to improve overall success rate to save a thrombosed graft for hemodialysis. The great difference showed between primary and primary assisted patency demonstrates the necessity of a close follow-up.

Effect of the time to intervention on the outcome of thrombosed dialysis access grafts managed percutaneously

PURPOSE

We aimed to investigate the effect of the time interval from the clinical presentation of a thrombosed dialysis access graft to intervention on procedure success.

MATERIALS AND METHODS

Records from two academic institutions for patients who underwent percutaneous thrombectomy of occluded surgical hemodialysis graft access sites in interventional radiology from 2006 to 2011 were reviewed retrospectively. The following data were recorded: gender, age, time and date of the initial request for a thrombectomy and the procedure, age of the surgical access, angiographic outcome, and clinical outcome (successful or unsuccessful postinterventional dialysis). Univariate and multivariate logistic regression were used to evaluate whether the time to intervention significantly affected the study endpoint.

RESULTS

In total, 268 percutaneous thrombectomies were performed in 139 patients. Of these 224 (83.5%) were categorized as successful and 44 (16.4%) as unsuccessful. The time to intervention was 19.9±30.1 vs. 22±35 hours for successful and unsuccessful procedures, respectively. The difference between the two was not significant, and there were also no significant differences in covariate distributions between successful and unsuccessful outcomes.

CONCLUSION

During the first 72 hours following clinical presentation of a thrombosed dialysis access graft, time to intervention may be considered independent of procedure outcome.

Hemodialysis catheter thrombi: visualization and quantification of microstructures and cellular composition

PURPOSE

Despite the increasing use of central venous catheters (CVC) for hemodialysis in clinical practice, the role of CVC in thrombus development is poorly understood. This work aims at defining new methods and protocols for assessing the micromorphology and composition of thrombi formed into tunneled and non-tunneled hemodialysis CVC removed from patients. 


METHODS

Twenty-nine CVCs were collected and the microscopic features of intra-luminal thrombi were quantified by scanning electron microscopy (SEM) and visualized by two photon laser scanning microscopy (TPLSM). 


RESULTS

SEM quantification showed that fibrin was the most abundant structure in CVC thrombi. Specifically, the median micromorphologic composition of the surface layer resulted in: 42.6% of fibrin plaque, 16.3% of fibrin network, 0.4% of fibrin fibers, 9.3% of platelets, 10.3% of erythrocytes and 1.7% of white blood cells. TPLSM showed that sub-surface layers were instead composed by smaller amounts of fibrin and platelets and higher amounts of blood cells.


CONCLUSIONS

Integration of SEM and TPLSM was found to be an excellent tool for characterizing thrombi in hemodialysis CVC removed from patients. Protocols and techniques presented here may be useful in the development and testing of new strategies for limiting thrombus formation on vascular access because of CVC.

Most important chronic complications of arteriovenous fistulas for hemodialysis

The aim of this review was to highlight the most important complications of arteriovenous fistulas (AVFs) for hemodialysis (HD). The quality of vascular access for HD should be suitable for repeated puncture and allow a high blood flow rate for high-efficiency dialysis with minimal complications. The dialysis staff must be well versed in manipulation of the AVF, and there should be a minimal need for corrective interventions. Construction of an AVF creates conditions for increasing the flow of blood through the venous system. Fulfillment of these conditions reduces the risk of turbulence and endothelium injury, which, in turn, minimizes the potential for stenosis. An AVF is closest to the ideal model of vascular access. The most important complications of fistulae for HD are lymphedema, infection, aneurysm, stenosis, congestive heart failure, steal syndrome, ischemic neuropathy and thrombosis. In HD patients, the most common cause of vascular access failure is neointimal hyperplasia. It is important to gain information about early clinical symptoms of AVF dysfunction in order to prevent and adequately treat potential complications.

Flash pulmonary oedema after relief of haemodialysis graft stenosis

Heart failure (HF) and chronic kidney disease (CKD) are undoubtedly very much interrelated, especially in patients with end-stage renal disease (ESRD) who are dependent on renal replacement therapy. Haemodialysis (HD) is of particular interest in cardiovascular patients due to the creation of a haemodialysis vascular access and the haemodynamic changes associated with it. Adequate HD though is very dependent on a properly functioning vascular access. Unfortunately, these surgical vascular accesses are vulnerable to stenoses and occlusions. Percutaneous endovascular treatment of these stenoses is often performed and has been found to be safe and effective. Despite its frequent use, acute medical complications of this percutaneous procedure have not been well-documented. In this report, we describe a patient who developed flash pulmonary oedema after balloon angioplasty treatment of an arteriovenous graft (AVG) stenosis.

Retroperitoneal approach for lower extremity arteriovenous graft as long-term vascular access in a complex case

A 76-year-old woman with stage 5 chronic kidney disease requiring hemodialysis had a long history of hypertension and diabetes. Her venous access was exhausted because of several previous access procedures including autogenous arteriovenous fistula operations and central venous catheter placements. After evaluating the function of her vessels when she was transferred to Renji hospital, we created an arteriovenous graft via a retroperitoneal approach in her right lower extremity. We inserted two grafts into her right thigh, a straight external ring and a loop graft. Twenty days after operation the patient's new access was successfully used in the treatment of hemodialysis. She has been followed up to now without occurrence of any graft-related events.

Effect of timing of the first cannulation on survival of arteriovenous hemodialysis grafts

The use of an arteriovenous graft as vascular access for hemodialysis is associated with a high rate of patency loss. The influence of timing of the first cannulation of the graft on graft survival has not been sufficiently studied. The purpose of this study was to investigate an association between the timing of the first cannulation of the polytetrafluoroethylene arteriovenous graft and the incidence of 12-month failure. This is a retrospective study on a cohort of chronic hemodialysis patients treated in a single center. According to the time, in weeks, between graft construction and its first successful cannulation, the grafts were divided into six groups: 2nd, 3rd, 4th, 5th, 6th and 7th or more week after surgery. The primary outcome was primary graft failure at 12 months, defined as the first occurrence of graft thrombosis or any invasive access procedure. The secondary outcome was cumulative graft failure at 12 months, defined as complete loss of the access site for dialysis. Fifty-eight patients with 64 newly-created arteriovenous grafts were included in the study. In the whole cohort, the incidence of primary graft failure at 12 months was 72.2%, and the incidence of cumulative graft failure at 12 months was 40.7%. The incidences of primary graft failure and cumulative graft failure at 12 months did not differ significantly between the study groups. In our study, timing of the first cannulation of a new arteriovenous polytetrafluoroethylene graft had no significant impact on graft survival.

Vascular access today

The number of patients with chronic kidney disease requiring renal replacement therapy has increased worldwide. The most common replacement therapy is hemodialysis (HD). Vascular access (VA) has a key role for successful treatment. Despite the advances that have taken place in the field of the HD procedure, few things have changed with regards to VA in recent years. Arteriovenous fistula (AVF), polytetrafluoroethylene graft and the cuffed double lumen silicone catheter are the most common used for VA. In the long term, a number of complications may present and more than one VA is needed during the HD life. The most common complications for all of VA types are thrombosis, bleeding and infection, the most common cause of morbidity in these patients. It has been estimated that VA dysfunction is responsible for 20% of all hospitalizations. The annual cost of placing and looking after dialysis VA in the United States exceeds 1 billion dollars per year. A good functional access is also vital in order to deliver adequate HD therapy. It seems that the native AVF that Brescia and Cimino described in 1966 still remains the first choice for VA. The native forearm AVFs have the longest survival and require the fewest interventions. For this reason, the forearm AVF is the first choice, followed by the upper-arm AVF, the arteriovenous graft and the cuffed central venous catheter is the final choice. In conclusion, VA remains the most important issue for patients on HD and despite the technical improvements, a number of problems and complications have to be resolved.

Hemodialysis Graft Resistance Adjustment Device

Up to eight percent of patients develop steal syndrome after prosthetic dialysis access graft placement, which is characterized by low blood flow to the hand. Steal syndrome results in a cold hand, pain, and in extreme cases, loss of function and tissue damage. A practical and easy way of adjusting the fluidic resistance in a graft to attenuate the risk of steal physiology would greatly benefit both surgeons and patients. This paper describes the design and development of a device that can be attached to a dialysis access graft at the time of surgical implantation to enable providers to externally adjust the resistance of the graft postoperatively. Bench level flow experiments and magnetic setups were used to establish design requirements and test prototypes. The Graft Resistance Adjustment Mechanism (GRAM) can be applied to a standard graft before or after it is implanted and a non-contact magnetic coupling enables actuation through the skin for graft compression. The device features a winch-driven system to provide translational movement for a graft compression unit. We expect such a device to enable noninvasive management of steal syndrome in a manner that does not change the existing graft and support technologies, thus reducing patient complications and reducing costs to hospitals.