Autologous Fistula Research Articles

Ethnic differences in arm vein diameter and arteriovenous fistula creation rates in men undergoing hemodialysis access

The National Kidney Foundation recommends that arteriovenous fistulas (AVFs) be placed in at least 65% of hemodialysis patients. Some studies suggest that African American patients are less likely to receive a first-time AVF than patients of other ethnicities, although the reason for this disparity is unclear. The purpose of our study is to determine (1) whether there are ethnic differences in AVF creation, (2) whether this may be related to differences in vein diameters, and (3) whether AVF patency rates are similar between African American and non-African American male patients. Consecutive male patients undergoing first-time hemodialysis access from 2006 to 2010 at two institutions were retrospectively reviewed. Data collected included age, ethnicity, weight, height, body mass index, diabetes, hypertension, congestive heart failure, smoking history, intravenous drug abuse, need for temporary access placement, and preoperative venous ultrasound measurements. Categoric variables were compared using χ(2) analysis, and the Wilcoxon rank-sum test was used to compare continuous variables. Of 249 male patients identified, 95 were African American. Median age in African American and non-African American patients was 63 years. Hypertension and hyperlipidemia were statistically significantly greater in African American patients. The need for temporary access before hemoaccess was similar between the cohorts. African American patients demonstrated significantly smaller median basilic and cephalic vein diameters at most measured sites. Overall, 221 of 249 (88.8%) underwent AVF first. An AV graft was created in 17.9% of African American patients vs in only 7.1% of non-African Americans (odds ratio, 2.8; 95% confidence interval, 1.3-6.4; P = .009). The difference between median vein diameters used for autologous fistula creation in African American and non-African American patients was not significant. There was no significant difference in the primary patency (80.8% vs 76.2%; P = .4), primary functional patency (73.1% vs 69.2%; P = .5), or secondary functional patency rates (91.0% vs 96.5%; P = .1). Average primary fistula survival time was 257 days in African American and 256 in non-African American patients (P = .2). African American patients are less likely than non-African American patients to undergo AVF during first-time hemodialysis access surgery. This ethnic discrepancy appears to be due to smaller arm vein diameters in African American patients. In African American patients with appropriate vein diameters who do undergo AVF, primary and functional patencies are equivalent to non-African American patients.

Outcomes of AngioJet® Thrombectomy in Hemodialysis Vascular Access Grafts and Fistulas: Pearl I Registry

Results are reported from the PEARL I Registry for procedures where a mid-length AngioJet catheter was used for thrombosed hemodialysis arteriovenous grafts and fistulae. The PEARL I Registry was a prospective, multicenter, observational database collecting information on the AngioJet procedures for a variety of thrombotic conditions. Patient demographics, procedural information, outcome data, and safety information were collected through 3 months postprocedure on AngioJet procedures. This paper describes the data collected for subjects presenting with hemodialysis access thrombosis. A total of 72 (16%) of the 452 subjects enrolled in the PEARL 1 Registry had thrombosed hemodialysis access sites. Procedural success was reported in 66/72 subjects (92%); surgical interventions were required in 6/72 subjects (8%). There was a statistically significant improvement (p<0.0001) in vessel occlusion from baseline to final angiography. Eighty-eight percent of access sites were patent at the end of the procedure and 97% of vessels showed improved occlusion status of =1 grades. Among prosthetic grafts, 53% (20/38) remained patent at the 3-month follow-up, 18% (7/38) were restenosed, and 29% (11/38) rethrombosed. Among autologous fistulas, 86% (18/21) remained patent without intervention at the 3-month follow-up; 3 fistulas rethrombosed. Four subjects (5%) died; none of the deaths were considered related to the AngioJet device or procedure. Outcomes from the PEARL I registry corroborate other studies of AngioJet thrombectomy and the overall literature of endovascular thrombectomy procedures. A high procedural success rates with acceptable near-term patency rates and low rates of adverse events are achieved with AngioJet thrombectomy.

Early Cannulation Prosthetic Graft (Flixene™) for Arteriovenous Access

Preferred hemodialysis (HD) access is an autologous fistula. Vascular grafts are used in patients with vessels unsuitable to accomplish an arteriovenous fistula (AVF). It is recommended that most current grafts mature in situ for 2-3 weeks before being accessed. Graft complications occur because the structure was not designed for the trauma of repeated cannulation. This study graft has a different structure that enables early use. Its design minimizes weeping through the graft walls and is meant to endure repeated access, thus minimizing the use of HD catheters. The purpose of this study was to show that the Flixene™ graft can be safely placed in patients where fistulas have failed and can be cannulated in 24-72 hr, while maintaining patency rates similar to other polytetrafluoroethylene (PTFE) grafts on the market. Flixene™ configuration should also reduce the incidence of pseudoaneurysms and seromas. A prospective two-center study placed 33 grafts in 33 patients; graft efficacy, post-operative complications, and patency were evaluated. Ease of cannulation and dialysis center complications related to early cannulation were documented. Six month follow-up data was analyzed. Successful access was achieved in all 33 patients within 72 hr (29 patients within 24 hr). Overall primary patency at 6 months was 49%; primary-assisted patency at 6 months was 80%. No pseudoaneurysms or seromas were documented at 6 months. Complications were typical of graft access. Early cannulation was successful in all patients. Primary and secondary patency rates at 6-months were equivalent to other data reported on PTFE grafts. Flixene™ successfully prevented pseudoaneurysm and seroma formation at 6 months of prospective follow-up. This graft is a better last-resort option for patients who cannot receive a fistula, compared to double-lumen cuffed catheters.

New Biological Solutions for Hemodialysis Access

Since Scribner described the first prosthetic chronic dialysis shunt in 1961, the surgical techniques and strategies to maintain vascular access have improved dramatically. Today, hundreds of thousands of patients worldwide are treated with some combination of native vein fistula, synthetic vascular graft, or synthetic semipermanent catheter. Despite significantly lower efficacy compared with autologous fistulae, the basic materials used for synthetic shunts and catheters have evolved surprisingly slowly. The disparity between efficacy rates and concomitant maintenance costs has driven a strong campaign to decrease the use of synthetic grafts and catheters in favor of native fistulae. Whether arguing the benefits of Fistula First or "Catheter Last," the fact that clinicians are in need of an alternative to expanded polytetrafluoroethylene (ePTFE) is irrefutable. The poor performance of synthetic materials has a significant economic impact as well. End-stage renal disease (ESRD) accounts for approximately 6% of Medicare's overall budget, despite a prevalence of about 0.17%. Of that, 15%-25% is spent on access maintenance, making hemodialysis access a critical priority for Medicare. This clinical and economic situation has spawned an aggressive effort to improve clinical care strategies to reduce overall cost and complications. While the bulk of this effort has historically focused on developing new synthetic biomaterials, more recently, investigators have developed a variety of cell-based strategies to create tissue-engineered vascular grafts. In this article, we review the evolution of the field of cardiovascular tissue engineering. We also present an update on the Lifeline™ vascular graft, an autologous, biological, and tissue-engineered vascular graft, which was the first tissue-engineered graft to be used clinically in dialysis patients.

The Brachiobasilic Arteriovenous Fistula: Effect of Patient Variables

The hemodialysis population is constantly expanding as patients on dialysis have increased longevity and the number of kidneys available for transplantation remains static (1). After radiocephalic and brachiocephalic fistulas have been exhausted the use of the autologous brachiobasilic fistula (BBAVF) should be considered prior to use of a synthetic graft. We present our single center experience of 140 brachiobasilic fistulas in a five-year period and examine any factors that influence patency and long-term function. Patients who had undergone formation of a BBAVF between January 2004 and January 2009 were identified; a review of all case notes and databases was undertaken. Details on demographics, cause of renal failure, co-morbidities (including diabetes, cardiac morbidity, hypertension, peripheral vascular disease), dialysis status at the time of fistula creation, hemoglobin, anti-coagulation regimens, and complications from surgery were recorded. Patency (defined as use of AVF for dialysis) was 83% at 3 months, 77% at 6 months, and 69% at 12 months. Length of patency ranged from 0 to 1918 days (at study cut-off) with a mean patency of 532 days. Factors found to significantly affect fistula patency included age over 60 (P=<0.001) and presence of peripheral vascular disease (P=0.048). Our brachiobasilic fistula patency rates are comparable with published literature and other fistulas. Within our population patient variables including age over 60 and the presence of peripheral vascular disease are associated with worse outcomes as would be expected. In spite of these factors we feel the brachiobasilic fistula is an excellent option for patients with more challenging access and should certainly be undertaken prior to the use of prosthetic grafts.

Clinical outcomes following endovascular treatment of the malfunctioning autologous dialysis fistula

There is limited long-term prospective data on the use of endovascular techniques and the use of thrombolysis in malfunctioning autologous haemodialysis fistulas. Prospective assessment of clinical outcomes following angioplasty with or without low-dose thrombolysis was undertaken in patients who presented with malfunctioning autologous haemodialysis fistulas. Consecutive patients referred to our department over a 6-month period were included. Twenty-five patients underwent percutaneous intervention by angioplasty alone (n = 14), angioplasty and stent (n = 2), thrombolysis alone (n = 2), angioplasty, thrombolysis and stent (n = 2) and angioplasty and thrombolysis (n = 5). Patients underwent clinical follow-up and were reviewed at 6, 12, 18 and 24 months to determine fistula status. Thirty-day mortality in the group was two patients. Statistical analysis was performed with Mann-Whitney, chi-squared and Kruskal-Wallis tests. Kaplan-Meier curves were constructed to compare primary and secondary patency rates. Technical success and initial clinical success rates were 88% and 76%, respectively. Primary and secondary clinical success rates at 6 months were 68% and 72%, at 12 months were 68% and 72%, at 18 months were 60% and 68% and at 24 months were 52% and 68%, respectively. There were no major complications following interventional procedures. There were four minor complications. After an initially successful procedure, five patients required subsequent intervention during the follow-up period. The overall fistula event rate was very low (five per 600 patient months or 0.0996 per access year) with a fistula loss rate of 0.14 per access year. Our results confirm that excellent clinical results can be achieved by percutaneous endovascular treatment in malfunctioning autologous fistulas, justifying their continued use as first-line management.

Use of Bovine Mesenteric Vein in Rescue Vascular Access Surgery

We describe a technique for rescue surgery of autologous arterovenous fistula (AVF), using bovine mesenteric vein (BMV), which may be used in patients with autologous AVF malfunction caused by steno-occlusion on the arterial side or by fibrosis of the first portion of the vein. To preserve the autologous AVF, we replaced the diseased portion of the artery, or the first centimeters of the vein, by a segment of BMV, with the aim of saving the patency and functionality of the access. We used this technique in 16 cases. All patients underwent hemodialysis treatment immediately after the procedure. Infection or aneurismal dilatation of the graft in implanted BMV was never observed.

Autologous Arteriovenous Fistula Creation by Nephrologists

In 1966, physicians from the Bronx Veterans Administration Hospital, New York City described the surgical creation of a distal radial artery to cephalic vein AV fistula. This novel configuration, for the first time, allowed effective and reproducible cannulation for hemodialysis access and has remained the gold standard for hemodialysis access since. More than 40 years later, vascular access remains the Achilles' heel of hemodialysis therapy. In this article, we will review the outcomes and techniques of the pre-eminent nephrologist-surgeons from around the world in an attempt to define those elements that are necessary for successful autologous fistula creation. The hope is that these elements may be employed by others in an effort to increase the numbers and durability of autologous fistulae in incident and prevalent hemodialysis patients, particularly in the United States.

Thrombosis in vascular accesses for haemodialysis: rescue treatment using invasive vascular radiological techniques

The purpose of this paper is to communicate our experience in the salvage of thrombosed haemodialysis vascular accesses using interventional radiology techniques. In the last four years, we have treated, by radiological means, 101 thrombosed haemodialysis vascular accesses. There were 44 autologous arteriovenous fistulas (43.56%) and 57 PTFE grafts (56.44%). There were 69 men (68.3%) and 32 women (31.7%). The mean age was 67.73 years (range 33-84). The mean vascular access age was 23.79 months (range 1-132). Manual catheter-directed aspiration was used. Fragmented, triturated or pushed the thrombus against the pulmonary circulation was avoided in all cases. 78 accesses were salvaged (77.2%). Autologous fistulas average and PTFE grafts success rate were 84.44% and 71.42% respectively. Angioplasty in one or more lesions after thromboaspiration was performed in all accesses, except six (5.9%). Metallic endoprostheses were implanted in 14 accesses (13.9%). Mean follow-up was 9 months (range 0-44). Primary patency was 42.3% +/- 5 at 6 months and 32% +/- 4 at one year. Autologous fistulas patency was better than PTFE grafts patency (p < or =0,05). Our results suggest thrombosed autologous arteriovenous fistulas salvage is better than PTFE grafts. This justifies interventional radiology techniques in these situations.

The natural history of autologous fistulas as first-time dialysis access in the KDOQI era

Patients on hemodialysis depend on durable, easily maintained vascular access. The autologous arteriovenous fistula (AVF) has been the gold standard since the introduction of the Brecia-Cimino fistula in 1966 and is echoed in the current Kidney Disease Outcomes and Quality Initiative (KDOQI) guidelines. The purpose of this study is to determine the natural history of AVF in patients requiring first-time permanent access in a large academic vascular surgery practice. We performed a retrospective review of patients undergoing new access creation from January 1, 2005 to June 30, 2005. The study group consisted of patients with no prior permanent access that underwent AVF creation. Categorical data was compared using chi2 analysis, nominal data was compared using Student t-test, and patency was determined by Kaplan-Meier curves. During the 6-month period, there were 80 first time AVF creations. The majority of patients were male (69%), African American (55%), and a history of diabetes (55%) and hypertension (96%). Seventy-five percent of patients were already undergoing hemodialysis via catheter access. Seventy-six percent of patients underwent preoperative vein mapping with a mean vein diameter of 3.1 mm. Twenty-six radiocephalic AVF (RCAVF) and 54 brachiocephalic AVF (BCAVF) were created with a mean follow-up of 278 days. At the end of follow-up, 38 (48%) AVF were being used for hemodialysis and only nine (11%) matured without the need for additional intervention. Mean time for AVF maturation was 146 days. Thirty AVF (37%) were abandoned, 16 (20%) of which were primary failures. Mean time to abandonment was 162 days. Twelve (15%) AVF remained patent but were never cannulated. The intervention rate was 1.33 interventions/patient/year and 75% of interventions were percutaneous. Kaplan-Meier analysis determined primary, primary-assisted, and secondary patency was 36% +/- 8.3, 55% +/- 6.5, and 55% +/- 6.5 at 1 year, respectively. Cumulative functional patency was 63% at 1 year. In patients receiving a first time permanent access, we found that the majority were AVF and they resulted in low primary patency rates at 1 year and long maturation times. KDOQI encourages AVF creation in order to increase AVF use for dialysis, but the strategy of simply increasing the number being created may not lead to the desired result and potentially lead to an increase in catheter dependence.

Invited commentary

In this series of patients receiving an initial, autogenous arteriovenous fistula (AVF), the reported primary patency at 1 year (36%) is low relative to other series. The authors attribute this to an aggressive approach to the placement of autogenous fistulas. In concluding, they note that adherence to the Kidney Disease Outcomes Quality Initiative (K/DOQI) strategy may not result in increased AVF utilization and may prolong catheter dependence. While the manuscript describes their experience after publication of the K/DOQI guidelines, not all elements of the guidelines were followed. For the placement of an AVF to occur in a timely manner: (1) patients must have access to the healthcare system; (2) chronic kidney disease must be recognized by primary providers; (3) patients must be referred to nephrologists for pre-dialysis care; and (4) nephrologists must make timely referral for hemodialysis access assessment and placement. For the patients in this series, there was a breakdown in one or more of these elements, as 78% of those referred for placement of first time vascular access were already dialyzing via central venous catheters. Once surgical referral occurs, K/DOQI emphasizes the importance of preoperative vein mapping, arterial assessment, and the preferred order of access placement to optimize the chance of maturing a functional fistula. Based on current literature and K/DOQI guidelines, arteries should be at least 2 mm and veins at least 2.5 mm, in diameter.1National Kidney Foundation Kidney Disease Outcomes Quality Initiative Clinical Practice Guidelines and Clinical Practice Recommendations.http://www.kidney.org/PROFESSIONALS/kdoqi/guideline_upHD_PD_VA/va_guide1.htmGoogle Scholar, 2Silva Jr, M.B. Hobson 2nd, R.W. Pappas P.J. Jamil Z. Araki C.T. Goldberg M.C. et al.A strategy for increasing use of autogenous hemodialysis access procedures: impact of preoperative noninvasive evaluation.J Vasc Surg. 1998; 27 (discussion 307-8): 302-307Abstract Full Text Full Text PDF PubMed Scopus (479) Google Scholar The order of preferred AVF placement is radiocephalic > brachiocephalic > brachiobasilic > arteriovenous grafts.1National Kidney Foundation Kidney Disease Outcomes Quality Initiative Clinical Practice Guidelines and Clinical Practice Recommendations.http://www.kidney.org/PROFESSIONALS/kdoqi/guideline_upHD_PD_VA/va_guide1.htmGoogle Scholar The authors are to be commended for a critical review of their experience, which highlights opportunities for change that may ultimately impact long-term functional patency. The study indicates that there is, perhaps, a role for a unified approach to dialysis access. It is possible that patency may have been adversely impacted by the disparate approach of the 15 surgeons in this group and their lack of adherence to K/DOQI guidelines. Some of the surgeons proceeded directly to use of a prosthetic graft when patients were not candidates for radiocephalic or brachiocephalic fistulas, instead of attempting a brachiobasilic fistula. Only 76% of patients in this study underwent preoperative mapping. Despite mapping, veins with diameters as small as 1.3 mm were used for fistulas. Even after access had been placed, times to cannulation seem prolonged. While we have a limited understanding of why fistulas fail, we do know that fistulas are more likely to fail when minimum requirements are not met. A standardized approach is crucial not only for clinical outcomes, but for our ability to study access outcomes. The goal is not to simply place an AVF, but to place an access that can be utilized for hemodialysis. The natural history of autologous fistulas as first-time dialysis access in the KDOQI eraJournal of Vascular SurgeryVol. 47Issue 2PreviewPatients on hemodialysis depend on durable, easily maintained vascular access. The autologous arteriovenous fistula (AVF) has been the gold standard since the introduction of the Brecia-Cimino fistula in 1966 and is echoed in the current Kidney Disease Outcomes and Quality Initiative (KDOQI) guidelines. The purpose of this study is to determine the natural history of AVF in patients requiring first-time permanent access in a large academic vascular surgery practice. Full-Text PDF Open Archive

Use of the Vectra Polyetherurethaneurea Graft for Dialysis Access in HIV-Positive Patients With End-Stage Renal Disease

The primary objective of this study was to establish the safety, efficacy, infection rate, and patency of the Vectra graft (polyetherurethaneurea) for dialysis access in patients diagnosed with human immunodeficiency virus (HIV) and end-stage renal disease. The Vectra graft has a unique self-sealing property; therefore we hypothesize that these patients will have fewer infections. A Vectra graft was implanted in 30 consecutive HIV-positive patients without sufficient veins for an autologous fistula. These surgeries were carried out over a 2.5-year period. Primary graft patency was 42% at 12 months and 3 (10%) of the grafts developed infection. This rate of graft infection was less (10% vs 45%) than both our prior experience and published reports using polytetrafluorothene bridge grafts. The unique self-sealing property of the Vectra graft minimizes the development of perigraft hematoma with repetitive needle cannulation and in the immunosuppressed HIV-positive patient, may account for the observed decrease in dialysis access infection.

Forensic issues in cases of fatal hemorrhage from arteriovenous dialysis access sites.

Angioaccess sites to enable repetitive vascular punctures for hemodialysis include temporary or permanent indwelling catheters, port access devices, autogenous vessels in native arteriovenous fistulas, or non-autogenous material in prosthetic arteriovenous grafts. While complications such as thrombosis and infection are well recognized, lethal hemorrhage is much less commonly encountered. In this paper, selected cases are reported to demonstrate the range of situations that may be encountered at autopsy, including hemorrhage from a catheter in a case of suicide, and hemorrhage from an arteriovenous fistula and an arteriovenous graft. Predisposing factors to hemorrhage include coagulation abnormalities due to anticoagulant therapy or to underlying renal failure, stenosis or obstruction that has resulted in increased intraluminal pressure, local sepsis, repeated trauma from venesection and hypertension. An approach to such cases should include careful evaluation of the medical history and death scene, with dissection at autopsy of catheters, grafts and fistulas to demonstrate the condition of anastomosis sites, and the presence or absence of ruptures, perforations, stenoses, and/or thromboses. Histologic sampling of autologous fistula walls and surrounding soft tissues may reveal evidence of sepsis.

Novel thromboresistant materials

The development of a clinically durable small-diameter vascular graft as well as permanently implantable biosensors and artificial organ systems that interface with blood, including the artificial heart, kidney, liver, and lung, remain limited by surface-induced thrombotic responses. Recent breakthroughs in materials science, along with a growing understanding of the molecular events that underlay thrombosis, has led to the design and clinical evaluation of a variety of biologically active coatings that inhibit components of the coagulation pathway and platelet responses by surface immobilization or controlled release of bioactive agents. This report reviews recent progress in generating synthetic thromboresistant surfaces that inhibit (1) protein and cell adsorption, (2) thrombin and fibrin formation, and (3) platelet activation and aggregation.

Definición de procesos e indicadores para la gestión de accesos vasculares para hemodiálisis

The prevalence of renal replacement therapy has increased, affecting 885 patients per million inhabitants. More than 50% of these patients require hemodialysis with permanent vascular access. In our center a multidisciplinary group was organized to manage processes related to vascular access for hemodialysis. To define processes for the management of vascular access for hemodialysis and to evaluate these processes. Setting. Level III hospital in the autonomous community of Madrid serving 485,000 inhabitants. 2002-2004. A multidisciplinary working group was set up. The three most frequent processes were defined and described. Flow charts were used for graphical representation. Quality criteria and indicators were defined with prospective monitoring of electronic medical records, design of a specific surgical protocol, and retrospective analysis. Comparison of the results with the literature. First vascular access. The percentage of patients with arteriovenous fistulas on starting hemodialysis. Percentage of prevalent patients with venous access (autologous fistula, prosthetic device, catheter). Maintenance of access: Rate of thrombosis in autologous-prosthetic arteriovenous fistulas. Percentage of rescued arteriovenous fistulas after thrombosis. Rate of temporary catheters. Resource management. Percentage of ambulatory interventions. Rate of admissions related to arteriovenous fistulas. Arteriovenous fistulas are the main source of morbidity and hospital admission in patients with chronic renal failure in hemodialysis programs. Multidisciplinary management achieves results above the standards described in the literature. There do not appear to be other determining factors for these results, since the technical procedures performed do not differ from those described in the literature.

Vascular Access in Children: The Importance of Microsurgery for Creation of Autologous Arteriovenous Fistulae

Microsurgery gives much better immediate and long term results than classical surgery for the creation of direct arteriovenous fistulae, the best chronic access to blood in children.

A Modified Technique for Endoscopic Transposition of Upper Arm Basilic Vein in Autologous Arteriovenous Fistula Creation

A good functioning arteriovenous (AV) fistula or prosthetic graft is indispensable to a hemodialysis-dependent renal failure patient. The superiority of an autologous AV fistula to a prosthetic graft is well known, but the creation of a native AV fistula is usually difficult in older or re-do patients due to the scarcity of usable superficial veins. The transposition of the upper arm basilic vein for brachiobasilic AV fistula creation provides the advantages of an autologous fistula. However, more pain and wound complications from the larger incision have made this procedure less commonly performed. Presently, endoscopic harvesting of the great saphenous vein employed in coronary bypass surgery is feasible and effective in reducing wound complications. We report the modified technique and cases using endoscopic transposition of the upper arm basilic vein for brachiobasilic fistula creation.

A Modified Technique for Endoscopic Transposition of Upper Arm Basilic Vein in Autologous Arteriovenous Fistula Creation

A good functioning arteriovenous (AV) fistula or prosthetic graft is indispensable to a hemodialysis-dependent renal failure patient. The superiority of an autologous AV fistula to a prosthetic graft is well known, but the creation of a native AV fistula is usually difficult in older or re-do patients due to the scarcity of usable superficial veins. The transposition of the upper arm basilic vein for brachiobasilic AV fistula creation provides the advantages of an autologous fistula. However, more pain and wound complications from the larger incision have made this procedure less commonly performed. Presently, endoscopic harvesting of the great saphenous vein employed in coronary bypass surgery is feasible and effective in reducing wound complications. We report the modified technique and cases using endoscopic transposition of the upper arm basilic vein for brachiobasilic fistula creation.

Haemoglobin level and vascular access survival in haemodialysis patients

A full correction of anaemia in haemodialysis (HD) patients may lead to an increased risk of vascular access (VA) failure. We studied the relationship between haemoglobin (Hb) level and VA survival. Incident patients between January 2000 and December 2002 with <1 month on HD were considered. The relative risk (RR) of access failure was evaluated in four different groups of patients divided according to their Hb level (<10, 10-12, 12-13 and >13 g/dl). Other factors possibly influencing VA survival were also considered: age, gender, diabetes, vascular disease, intact parathyroid hormone (iPTH) and treatment with an angiotensin-converting enzyme (ACE) inhibitor, angiotensin receptor blocker (ARB) or recombinant human erythropoeitin therapy. We studied 1254 patients (1057 with autologous fistulae, 75 grafts and 122 permanent catheters at admission). Based on Cox analysis, we found the next statistically significant RR of VA failure to be 2.3 times higher with grafts than with arterio-venous fistulae (AVFs) and 1.8 times higher in AVFs with Hb <10 g/dl than in AVFs of the next Hb group. There was no statistically significant difference in the RR of VA failure between patients with Hb 10-12 g/dl and those with Hb 12-13 g/dl or >13 g/dl. Diabetes (RR: 1.41, P = 0.06), age >65 years (RR: 1.32; P = 0.11) and iPTH (RR: 1.56; P = 0.01) were identified as predictive factors for VA failure; ACE inhibitors or ARB (RR: 0.69; P = 0.03) were found to be protective factors. In the studied population, the correction of Hb level to >12 g/dl was not associated with a higher incidence of VA thrombosis than in patients with Hb between 10 and 12 g/dl. ACE inhibitors or ARBs were found to be protective factors, and diabetes, age >65 years and iPTH >400 pg/ml were negative predictive factors for VA survival.

Dialysis Shunt Surgery Using Autologous Material

BACKGROUND: In order to enable effective haemodialysis the dialysis shunt should provide function and good puncture capacity. Fistulae with autologous material are the best prerequisites. METHODS: The available vessels must be treated economically. The surgeon works from peripheral to central. The first-order shunt location is the forearm, second the upper arm and third the upper thigh. Cimino fistula in the distal forearm is the golden standard. However, in principle, an autologous fistula is possible at any point on the forearm. The ulnar fistula should also be considered for differential surgery. The brachial fistula affords many possibilities. RESULTS: Shunt revisions should be carried out in the early stage of a failing shunt. At this time, the revisions are still relatively simple in technical terms and avoid damage to the shunt extremity. Reanastomosis (also termed proximal displacement) affords the best preconditions. The aim is to achieve immediate reuse of the old puncture site and avoidance of a Shaldon catheter which is most frequently applied. CONCLUSIONS: Shunt surgery is a highly difficult procedure which requires great vascular surgical skill and the ability to improvise. It is hence not a suitable operation to be embarked on by the beginner in vascular surgery.