Comparison of Ellipsys Percutaneous and Proximal Forearm Gracz-Type Surgical Arteriovenous Fistulas.

RATIONALE & OBJECTIVE: Percutaneous arteriovenous fistulas (AVF) are created by establishing a proximal forearm anastomosis and offer a safe and reliable vascular access. This study compares the Ellipsys percutaneous AVF with a proximal forearm Gracz-type surgical AVF, chosen for comparison as it is constructed at the same anatomical site. STUDY DESIGN: Retrospective study of prospectively collected clinical data. SETTING & PARTICIPANTS: All vascular access procedures conducted during a 34-month period were reviewed. The study groups comprised 89 percutaneous AVFs and 69 surgical AVFs. EXPOSURE: Percutaneous or surgical AVF placement. OUTCOME: AVF patency, function, and complications. ANALYTICAL APPROACH: Patency rates for each AVF group were evaluated by competing risk survival analysis using a cumulative incidence function. Association of primary, primary assisted, and secondary patency with the AVF groups was examined by Cox proportional hazard models. RESULTS: Technical success was 100% for both groups. Average procedure times were 14 minutes for percutaneous AVFs and 74 minutes for surgical AVFs (P < 0.001). Proximal radial artery (PRA) was used in all percutaneous AVF cases. Inflow for surgical AVFs included radial (30%), ulnar (12%), and brachial (58%) arteries. Outflow veins for both groups were the cephalic and/or basilic veins. Access flow volumes, times to maturation, and overall numbers of interventions per patient-year were not significantly different. Cumulative incidence of primary patency failure at 12 months was lower for surgical AVF (47% vs 64%, P = 0.1), but secondary patency failure was not different between groups (20% vs 12%, P = 0.3). PRA surgical AVFs had similar primary patency (65% vs 64%, P = 0.8) but higher secondary patency failure rates than percutaneous AVFs at 12 months (34% vs 12%, P = 0.04). LIMITATIONS: Retrospective study with a relatively short follow-up period, and not all patients required hemodialysis at the end of study. CONCLUSIONS: Both percutaneous and surgical AVFs demonstrated high rates of technical success and secondary patency. Percutaneous AVFs required shorter procedure times. The rate of intervention was similar. When a distal radial artery AVF is not feasible, percutaneous AVF might offer an appropriate procedure for creating a safe and functional access, maintaining further proximal forearm surgical AVF creation options.

Placing a primary arteriovenous fistula that works--more or less known aspects, new ideas.

Despite the pre-operative availability of well-defined criteria to create a primary arteriovenous fistula (AVF) a high early failure/missing maturation is complained worldwide. Based on new results from basic research using numerical techniques, the authors try to guide attention to a widely neglected field in published data: the unremarkable, small, but essential surgical details in creating a successful AVF. The aim is to describe their significance and to give them a place in a cross-border context.

Gracz fistula is a feasible option after two failed percutaneous arteriovenous fistulae.

Two devices for the creation of an endovascular percutaneous (pAVF) endovascular (endoAVF) arteriovenous fistulae (AVF) are available: the Ellipsys and the WavelinQ-4F systems. The main difference is the location of the anastomosis, making it feasible to use both pAVFs and surgical Gracz-type AVF in an algorithm sequence. A 66-year-old male patient with end-stage kidney disease and HIV was referred for a creation of a dialysis access after failed peritoneal dialysis. A radial-radial WavelinQ-pAVF with simultaneous coil embolization of a brachial vein was created but failed within 4 weeks. Therefore, an Ellipsys-pAVF was successfully created between the proximal radial artery and perforating vein on the same arm. After 2 days, however, the Ellipsys-pAVF anastomosis occluded. The ipsilateral Gracz-AVF was created, anastomosing perforating vein with the antecubital brachial artery. Cannulations were started 28 days later. During the follow up of 807 days, the AVF remained patent with last known volume flow of 1500 ml/min and no need for secondary interventions. We report a successful creation of a Gracz-AVF after primary failed pAVFs created with both pAVF-systems in a single patient and in the same arm. Thus, based on that case we recommend creation of pAVF prior to Gracz-AVF as integral part of Vascular Access creation algorithm, based on each patient's life plan.

Novel classification of proximal forearm perforator vein in the planning and creation of percutaneous and surgical Gracz-type arteriovenous fistulae.

BACKGROUND: The perforator vein determines whether it is feasible to create a percutaneous (pAVF) or surgical "Gracz-type" arteriovenous fistula (sAVF). Creating a standard anatomic classification of the antecubital region is beneficial to both the selection of the appropriate device and/or procedure and technical outcomes. Accordingly, an analysis of a large cohort of patients undergoing pAVF/sAVF was performed, focusing on perforator vein anatomical suitability, and a novel anatomical classification of the antecubital region was developed and proposed. METHODS: Between August 2018 and July 2022, chronic or end-stage kidney disease patients as well as patients anticipated an initiation of apheresis, who were referred for vascular access planning, underwent a standardized evaluation of upper extremities. A vessel mapping summary detailing the vasculature and the access creation plan was completed, indicating the anatomical suitability for sAVF and pAVF (Ellipsys and WavelinQ) techniques. RESULTS: Of 524 patients, 36.5% were female (average age 65 years). 53.2% were on dialysis, 41.6% had diabetes, and 13.2% had a previously failed permanent dialysis access. The anatomy for successful pAVF creation was judged to be suitable in 54% of patients for an Ellipsys-pAVF, and 29.8% for WavelinQ-pAVF. Of the WavelinQ group, 54.4% had suitable anatomy for ulnar, 26.9% for radial, and 18.6% for both ulnar/radial anastomoses. Additionally, 60.7% had suitable anatomy for pAVF creation with at least one of the systems, while 22.5% were suited for both types of pAVF-systems. 80.3% were candidates for creation of a Gracz-AVF. CONCLUSION: Overall, we found that about 60% of patients are likely candidates for a pAVF, with 80% being candidates for creation of a Gracz-AVF. Male patients have significantly higher suitability for most types of AVF creation, and younger patients are more suitable for Ellipsys-pAVF and RCAVFs. Most importantly, a universal classification of perforator vein was developed, which is indispensable in modern vascular access planning.

Perforating vein fistula is superior to forearm fistula in elderly haemodialysis patients with diabetes and arterial hypertension.

BACKGROUND: Access-related problems are one of the major causes of morbidity in elderly patients with chronic kidney disease. The aim of this study was to assess potential risks and benefits in elderly patients comparing forearm arteriovenous fistula (AVF) and perforating vein AVF below the elbow for primary vascular access. METHODS: A retrospective comparison of elderly patients (65.7 ± 9.3 years, 70.4% male patients, 36.2% late referral) undergoing primary vascular access surgery using forearm AVF (n = 50) and perforating vein AVF (n = 55) was performed over a 2-year period, including a multivariate analysis of potential risk factors and benefits of primary patency (PP = intervention-free access survival) and secondary patency (SP = access survival until abandonment). RESULTS: Patency rates after 24 months were significantly higher in patients with perforating vein AVF (PP + SP: 78.2%) compared to forearm AVF (PP: 62%, SP: 56%, P = 0.04). Presence of diabetes mellitus in patients with forearm AVF was associated with a decreased PP [odds ratio (OR): 3.6, 95% confidence interval (CI): 0.9-13.8] and SP (OR: 4.8, 95% CI: 1.3-17.9), and arterial hypertension was associated with a lower PP (OR: 6.7, 95% CI: 0.8-53.9), whereas the presence of hyperparathyroidism was associated with higher PP and SP (OR: 0.2, 95% CI: 0.1-0.7). In contrast, PP and SP in patients with perforating vein AVF were not influenced by comorbidities. CONCLUSIONS: Perforating vein AVF is superior to forearm AVF in elderly patients with diabetes and arterial hypertension due to the proximal fistula location, probably caused by an improved artery distensibility during fistula maturation.

The past and the future of vascular access surgery: Creation of percutaneous arteriovenous fistula using Ellipsys vascular access system in a patient with previous ipsilateral Scribner-shunt.

BACKGROUND: Sixty years after the first description of Scribner-shunt, and 54 years after publication of the first radio-cephalic arterio-venous fistula (AVF), endovascular percutaneous AVF (pAVF) was introduced. We report a successful case of Ellipsys-pAVF creation and use for hemodialysis in a patient with a previous ipsilateral Scribner-shunt. CASE: A 72-year old female patient with chronic kidney disease (CKD), previous right-sided Scribner-shunt and kidney transplant, underwent a successful creation of right-sided Ellipsys-pAVF. The procedure time was 12 min with intraoperative brachial artery volume flow of 720 ml/min. At 39 days, an ultrasound-guided balloon-angioplasty of the outflow cephalic vein stenosis was performed. Cannulations were started 41 days after the creation of pAVF. No additional interventions were required during the follow-up of 258 days with last follow-up volume flow of 1400 ml/min. CONCLUSIONS: This is the first report of the creation of pAVF in a patient with previous "traumatic" ipsilateral placement of a Scribner-shunt. It allows the creation of a small anastomosis in very short time, which can be successfully used for hemodialysis treatment on the same day, if necessary, and reduces the expected risk of high-flow AVF with associated peripheral steal and cardiac outcomes (especially in a patient with cardiomyopathy such this one).

Over-expression of IGF-related peptides in stenoses of native arteriovenous fistulas in hemodialysis patients.

INTRODUCTION: Insulin-like growth factors (IGFs) are known to play an important role in atherogenesis. The aim of our study was to assess the local expression of IGF-related peptides in stenosed hemodialysis fistulas and compare these with their respective serum levels. METHODS: We investigated 15 stenosed vein segments of primary arteriovenous fistulas, 29 non-stenosed control vein segments from uremic patients and 15 non-stenosed control saphenous vein segments. Immunohistochemistry was performed for IGF-I, insulin, IGF-binding proteins (IGFBPs)-1, -2, -3 and -4, the acid labile subunit (ALS) and type 1 IGF-receptor (IGF-R). Serum levels were measured by specific radioimmunoassays. RESULTS: Compared to both control groups, a significantly higher expression of the following IGF-related peptides was seen in the stenotic (neo)intima: IGF-I, IGFBP-1, -2, -3, -4 and IGF-R; in the stenotic media: IGF-I and IGFBP-3 and in the endothelium of stenotic fistulas: IGF-I (all p<0.05). Staining against ALS and insulin was negative in all vessels. Serum IGF-I levels did not differ. Serum levels of IGFBP-1, -2, -3 and -4 were significantly higher in patients with renal disease (all p<0.05). There were no correlations between local and systemic IGF-related peptide levels. There were correlations of neointimal expression of IGF-I, IGFBP-1, -2, -3, -4 and IGF-R with both hypercellularity and the presence of inflammatory cells (p<0.05). CONCLUSION: In the stenotic arteriovenous fistula of hemodialysis patients, expression of the peptides IGF-I, IGFBP-1, -2, -3, -4 and IGF-R was significantly increased and showed a positive correlation with neointimal inflammation and hypercellularity (all p<0.05). IGF-related peptides are most likely synthesized locally and might be involved in the initiation and/or progression of neointimal thickening of primary arteriovenous fistulas.

AV fistula creation in paediatric patients: outcome is independent of demographics and fistula type reducing usage of venous catheters.

PURPOSE: Even though early transplantation is still the first-line therapy in paediatric patients with end-stage renal disease (ESRD), up to 30% of these patients still require haemodialysis (HD). Creating an arteriovenous fistula (AVF) is quite challenging, particularly in children, leading to disproportional use of catheters. In this paper, we describe our experience in the creation of AVF with currently no in-dwelling catheters in children and adolescents on HD. METHODS: From January 2009 to December 2013, there were 34 patients rated as unfit for transplantation for at least the next 6 months or who had already been on HD through a central venous catheter (CVC). Three patients aged between 12 months and 3 years and weighing 9-12 kg were not suitable for AVF. Finally 31 patients, from 6 to 19 years of age with a mean weight of 43.3 ± 14.5 kg (19-80 kg), were assigned to the alternative of AVF. RESULTS: During the above-mentioned time period, 31 patients were provided with 32 AVFs; 26 received a distal radiocephalic fistula, five a Gracz-type fistula and one a brachio-basilic fistula. All but two fistulae matured primarily, within an average time of 45 (range: 16-191) days until the first dialysis. The fistula's 1-year primary and primary assisted patency rates were 78% and 94%, respectively. CONCLUSIONS: The creation of a native vascular access is an effective and durable procedure in paediatric and adolescent patients. It reduces using of CVCs and is appropriate both for long-term treatment and as a bridging procedure until renal transplantation.

Vascular access in the 21st century.

Worldwide, aged diabetic patients represent the most rapidly growing group of patients treated for endstage renal disease (ESRD). Pre-existing arterial as well as venous problems have led to a pessimistic view on the creation of vascular access in the future. In addition, more and more patients undergo hemodialysis therapy for twenty or thirty years with obvious vascular wastage. Personal experience in the interdisciplinary field of vascular access covering nephrology, vascular surgery and radiology clearly show that history is a good teacher. Since the introduction of the surgically created arterio-venous fistula by Brescia and Cimino in 1966, only minor progress has been seen; widespread use of different graft materials has produced mainly disappointing results, thus contributing to more temporary or permanent central venous catheters. Despite better catheter technology, essential problems like infection and thrombosis have not changed. The challenge for the 21st century is to find strategies and solutions to face these deteriorated conditions. The factors contributing to adequate vascular access are: an individually tailored approach with clear preference for native vessels, respecting basic hemodynamic rules, analysing past failures, combining careful preoperative investigations and meticulous surgical technique; continuous surveillance of fistula function and early, elective revision to prolong the lifespan of vascular access. An interdisciplinary team will be essential to achieve this goal.

Vascular access in the hemodialysis patient--personal experience and review of the literature.

There is consensus that arteriovenous (AV) fistulae represent the best choice for initial vascular access in patients suffering from chronic renal insufficiency (CRI) or end-stage renal disease (ESRD) approaching the need of initiating hemodialysis therapy. However, this is a challenging task in the rapidly growing population of diabetic, aged, and hypertensive patients. The preexisting damage of the vascular anatomy and the high cardiovascular comorbidity hinder construction of a well functioning arteriovenous fistula. Late referrals to the nephrologist delay access surgery and increase the use of temporary and cuffed tunneled catheters with all their potential risks. Nevertheless, various strategies and tools exist to overcome these problems. Early referral results in venous preservation and early selection of side, site, and type of initial vascular access. Ultrasound findings are essential components of preoperative investigations. Special attention should be paid to the quality of the arteries at each section along the forearm, the elbow region, and the upper arm. Dedicated, meticulous surgery is mandatory. Fistula monitoring and elective revision of the failing AV fistula will result in increasing longevity of the blood access, and will reduce morbidity and costs.

History of vascular access for haemodialysis.

The history of vascular access is a history of vascular surgery as well as a history of dialysis therapy. This survey is a personal view on the history of vascular access without the ambition to cover every detail, but with an effort to mention the major steps in a fascinating panorama.

Should nephrologists be in charge?

Once, vascular access (VA) for hemodialysis treatment was initiated by nephrologists: Scribner introduced the arteriovenous shunt, Shaldon the central-venous catheters and Brescia-Cimino the arteriovenous fistula. Later on, creating VA became a domain of surgery. Many nephrologists felt out of responsibility. Interventional procedures, angioplasty and stent insertion are mostly performed by radiologists. In 2005, the role of the nephrologist in comprehensive VA care must be newly identified. We know about the value of early referral to nephrologist and access surgeon to preserve venous vasculature. The nephrologist cares for clinical examination of vessels, for an ultrasound Doppler evaluation before the creation of primary VA with clear preference to native arteriovenous fistulae to aim at an early failure rate. Surveillance and monitoring require the exclusive responsibility of the nephrologist and his team. Early diagnosis of VA dysfunction allows elective revision before the onset of thrombosis. There should be an agreement on strategies between nephrology, surgery and radiology. Surgical techniques and skills are to be assessed from time to time. Worldwide, new organizational structures in creation, control and documentation of VA are needed. Flexibility between the disciplines involved as well as educational programs for nephrologists, surgeons and radiologists are future challenges.

The initial creation of native arteriovenous fistulas: surgical aspects and their impact on the practice of nephrology.

A highly welcomed, increasing number of arteriovenous fistulas (AVFs) has been noted in recent years as has a high rate of early failure. The latter is not an inevitable consequence of the former. Potential contributors may be identified by an analysis of surgical strategies and details of the creation of arteriovenous (AV) anastomoses. The "simple" AVF is all but simple. Construction of the anastomosis is a tool, not the aim of access surgery. The aim is a rapidly maturing and well-functioning fistula, a high flow construct that can be cannulated easily and repeatedly for adequate hemodialysis (HD) therapy. Surgical details are illustrated to clarify verbal descriptions. The impact of a high quality of initial vascular access on the practice of nephrology is mentioned. Closing remarks try to define a vascular access team as the optimal option for future management of vascular access.

Tailoring the initial vascular access for dialysis patients.

BACKGROUND: Creating a functioning initial arteriovenous (AV) access for aging and diabetic end-stage renal disease (ESRD) hemodialysis patients has been a challenge. METHODS: This study describes 748 consecutive primary AV access creations and their primary (unassisted) and secondary (assisted) access survival at a single center. Twenty-four percent of the patients had diabetes as their cause of ESRD and the average age was 59.6 years. No patient receiving an initial AV access required synthetic graft material. All received an AV fistula. Three types of fistulae were created and their distribution varied significantly for diabetic and non-diabetic patients (respective percentages): forearm AV fistula (24%, 62%), perforating vein fistula (PVF) at the elbow (48%, 21%) and non-PVF at the elbow (29%, 17%). RESULTS: Results of access survival for age groups <65 and 65+ years, male and female, diabetic and non-diabetic subgroups ranged from 51 to 75% for unassisted and from 75 to 96% for assisted two year access survival. PVF appeared to be advantageous over non-PVF access at the elbow. First intervention for peripheral steal syndrome was required at a rate of 7 and 0.6 per 100 patient-years at risk for diabetic and non-diabetic patients, respectively. The thrombosis rates per patient year of 0.03 for non-diabetics and 0.07 for diabetics are superior to previously published results for AV fistulae or for a combined AV fistula-AV graft approach. CONCLUSIONS: Potential explanations for these excellent results among elderly and diabetic patients include preoperative evaluation, exclusive use of native vessels, a variable surgical approach including PVF, and the experience of a single operator.

Increased expression of TGF-beta1 and IGF-I in inflammatory stenotic lesions of hemodialysis fistulas.

BACKGROUND: Hemodialysis fistula dysfunction due to stenotic lesions remains a frequent cause of hospitalization for hemodialysis patients. Transforming growth factor-beta(TGF-beta) and insulin-like growth factor-I (IGF-I) are known to be involved in atherogenesis. The latent TGF-beta1 binding protein-1 (LTBP-1) targets extracellular matrix (ECM) interactions and is involved in the regulation of TGF-beta latency. METHODS: We investigated the expression of TGF-beta1, LTBP-1 and IGF-I in 15 occluded or severely narrowed vein segments of primary arteriovenous fistulas, in 29 non-stenosed control veins from uremic, pre-dialysis patients, and in 15 non-stenosed control saphenous veins obtained from patients undergoing aortocoronary bypass grafting. Immunohistochemistry was performed on snap-frozen tissue specimens using antibodies recognizing either the latency-associated peptide of TGF-beta1 (96-1), LTBP-1 (Ab39) or IGF-I. Serum levels of TGF-beta1 and IGF-I were determined by commercially available IRMA. RESULTS: In stenosed hemodialysis fistulas, a pronounced intimal thickening with deposition of ECM was observed with light and electron microscopy. Infiltrating cells were seen in stenosed vessels, mostly in areas of intimal hyperplasia and in the media. TGF-beta1, LTBP-1 and IGF-I expression were mostly localized in the neointimal and medial layers, and were significantly higher than in the control groups. A positive correlation between the presence of inflammatory cells and the staining intensity for TGF-beta1, LTBP-1 and IGF-I was found in all vessels analyzed. CONCLUSION: Neointimal thickening of primary arteriovenous fistulas represents a local inflammatory process and appears to be associated with increased protein expression of TGF-beta1 and IGF-I. While local IGF-I is likely to stimulate smooth muscle cell proliferation in this setting, TGF-beta1 may be an important trigger of ECM production and deposition.