Establishing patient-specific criteria for selecting the optimal upper extremity vascular access procedure.

OBJECTIVE: The Kidney Disease Outcome Quality Initiative and Fistula First Breakthrough Initiative call for the indiscriminate creation of arteriovenous fistulas (AVFs) over arteriovenous grafts (AVGs) without providing patient-specific criteria for vascular access selection. Although the U.S. AVF rate has increased dramatically, several reports have found that this singular focus on increasing AVFs has resulted in increased AVF nonmaturation/early failure and a high prevalence of catheter dependence. The objective of this study was to determine the appropriateness of vascular access procedures in clinical scenarios constructed with combinations of relevant factors potentially influencing outcomes. METHODS: The RAND/UCLA Appropriateness Method was used. Accordingly, a comprehensive literature search was performed and a synthesis of results compiled. The RAND/UCLA Appropriateness Method was applied to 2088 AVF and 1728 AVG clinical scenarios with varying patient characteristics. Eleven international vascular access experts rated the appropriateness of each scenario in two rounds. On the basis of the distribution of the panelists' scores, each scenario was determined to be appropriate, inappropriate, or indeterminate. RESULTS: Panelists achieved agreement in 2964 (77.7%) scenarios; 860 (41%) AVF and 588 (34%) AVG scenarios were scored appropriate, 686 (33%) AVF and 480 (28%) AVG scenarios were scored inappropriate, and 542 (26%) AVF and 660 (38%) AVG scenarios were indeterminate. Younger age, larger outflow vein diameter, normal or obese body mass index (vs morbidly obese), larger inflow artery diameter, and higher patient functional status were associated with appropriateness of AVF creation. Older age, dialysis dependence, and smaller vein size were associated with appropriateness of AVG creation. Gender, diabetes, and coronary artery disease were not associated with AVF or AVG appropriateness. Dialysis status was not associated with AVF appropriateness. Body mass index and functional status were not associated with AVG appropriateness. To simulate the surgeon's decision-making, scenarios were combined to create situations with the same patient characteristics and both AVF and AVG options for access. Of these 864 clinical situations, 311 (36%) were rated appropriate for AVG but inappropriate or indeterminate for AVF. CONCLUSIONS: The results of this study indicate that patient-specific situations exist wherein AVG is as appropriate as or more appropriate than AVF. These results provide patient-specific recommendations for clinicians to optimize vascular access selection criteria, to standardize care, and to inform payers and policy. Indeterminate scenarios will guide future research.

Single-center results of a series of prosthetic axillary-axillary arteriovenous access grafts for hemodialysis.

OBJECTIVE: Prosthetic infraclavicular axillary-axillary arteriovenous access grafts are one of a number of complex dialysis access options in patients when all of the usual upper limb possibilities have been exhausted. We present a follow-up of 35 patients who received this access graft during a 9-year period. METHODS: Patients were identified from our own operation records. Follow-up data were gathered from their locally held electronic medical records. Primary and secondary patency were calculated using the Kaplan-Meier estimate. RESULTS: During the study period, 15 of the 35 patients in our cohort underwent one or more revision operations. Primary patency was estimated at 88% at 6 months, and the secondary patency rate estimate was 54% at 48 months. Twelve patients died during the study period; the grafts in 17 of the 23 remaining patients were in use at the conclusion of the study. CONCLUSIONS: Although this is a small cohort, our results suggest that prosthetic axillary-axillary arteriovenous access should be at least considered as a viable long-term option for hemodialysis patients.

Interobserver Reliability of Three Validated Scoring Systems in the Assessment of Diabetic Foot Ulcers.

Scoring systems for diabetic foot ulcers may be used for clinical purposes, research or audit, to help assess disease severity, plan management, and even predict outcomes. While many have been validated in study populations, little is known about their interobserver reliability. This prospective study aimed to evaluate interobserver reliability of 3 scoring systems for diabetic foot ulceration. After sharp debridement, diabetic foot ulcers were classified by a multidisciplinary pool of trained observers, using the PEDIS (Perfusion, Extent, Depth, Infection, Sensation), SINBAD (Site, Ischemia, Neuropathy, Bacterial infection, Depth), and University of Texas (UT) wound classification systems. Interobserver reliability was assessed using intraclass correlations (0 = no agreement; 1 = complete agreement). Thirty-seven patients (78.4% male) were assessed by a pool of 12 observers. Single observer reliability was slight to moderate for all scoring systems (UT 0.53; SINBAD 0.44; PEDIS 0.23-0.42), but multiple observer reliability was almost perfect (UT 0.94; SINBAD 0.91; PEDIS 0.80-0.90). The worst agreement for single observers was when scoring infection (SINBAD 0.28; PEDIS 0.28), ischemia (SINBAD 0.26; PEDIS 0.23), or both (UT 0.25); however, this improved to almost perfect agreement for multiple observers (infection: 0.83; ischemia: 0.80-0.82; both: 0.81). These classification systems may be reliably used by multiple observers, for example, when conducting research and audit. However, they demonstrate only slight to moderate reliability when used by a single observer on an individual subject and may therefore be less helpful in the clinical setting, when documenting ulcer characteristics or communicating between colleagues.

Surgical Options in the Problematic Arteriovenous Haemodialysis Access.

The aim of the paper is to review surgical options in problematic arteriovenous haemodialysis access--in particular, to explore and discuss some surgical alternatives to interventional radiology in the case of failing, failed or complicated arteriovenous access. There is copious evidence to support endovascular techniques to treat non-maturation, stenosis, thrombosis and other complications of arteriovenous access. However, there may be times when the surgery-first approach might be a useful adjunct, alternative or even preferable, including the creation or revision of an anastomosis in the forearm, which may yield better patency rates than endovascular intervention. The creation and maintenance of haemodialysis access can be a complex process and the surgeon and the interventional radiologist should work closely together. The distinct roles of the surgeon and the interventional radiologist in the treatment of a problematic arteriovenous access remain debatable and the authors suggest a multidisciplinary team approach when planning treatment of access complications, which may require repeated interventions.

The use of the early cannulation prosthetic graft (Acuseal™) for angioaccess for haemodialysis.

OBJECTIVES: Autogenous arteriovenous (AV) accesses are the preferred choice for the delivery of haemodialysis (HD). With an increase in the prevalence of end-stage renal disease and in the life expectancy of these patients, the quality and availability of superficial vessels can be limited and reduced with time. The use of prosthetic AV accesses may therefore become necessary for the delivery of HD. A new early cannulation vascular prosthesis (GORE® ACUSEAL Vascular Graft) has been introduced, developed to hinder suture line and cannulation needle bleeding. The authors report their experience with this new conduit at a London teaching hospital. METHODS: Between May 2011 and June 2013, 52 patients underwent 55 procedures where the ACUSEAL® prosthetic AV access was utilized to facilitate HD. The majority of procedures involved the placement of prosthetic brachio-axillary accesses or prosthetic axillo-axillary chest accesses. RESULTS: The 1-year primary and secondary patency was found to be 46% and 61%, respectively. Successful cannulation of the newly placed AV access was performed with 24 hours of surgery in 40 patients (73%). Tunnelled vascular catheters were required in only 10 (18%) patients. Six (11%) of the patients in the study suffered early complications, and 9 (16%) patients developed AV access infection. CONCLUSIONS: These results show that, while providing patency results that compare favourably to those published for other types of regular prosthetic accesses, the conduits are amenable to very early cannulation with few cannulation-related complications. This leads to a dramatic reduction in the need for temporary or tunnelled catheters.

Volume blood flow, static pressure ratio and venous conductance in native arterio-venous fistulae: three surveillance methods compared.

PURPOSE: Dialysis venous pressure monitoring has been widely recommended as a surveillance method but has not been shown to improve access outcomes in randomised controlled trials. The method has been impaired by the need to either turn off the blood pump or to derive the static venous pressure from the venous pressure measured with the dialysis pump running. We have developed a unique algorithm which converts Doppler-shifted spectral information derived from unscaled pulsatile blood flow waveforms into an estimate of mean blood pressure (MBP) at the point of ultrasound insonation. METHODS: We have devised the unique expression shown here: MBP = MAP/(1 + Pff/Vff) where MAP is the mean arterial pressure, Pff = (systolic - diastolic)/MAP measured on the contralateral arm and Vff = spectral maximum - minimum/mean. Venous conductance (VC) can be measured by combining this pressure data with Duplex ultrasound blood flow data. A new device BlueDop™ has been used to illustrate the potential clinical value of non-invasive static pressure ratio (SPRn) in a monitoring role. Duplex and BlueDop™ technology were tested in an arterio-venous fistula (AVF) study in which VC, Q and SPRn were compared. Thresholds used for detection of ≥60% venous stenosis were VC <10 mL min-1 mm Hg-1, Q <500 mL min-1, SPRn >0.56. RESULTS: The following accuracy was achieved: VC = 96%, Q = 92%, SPRn = 76% with similar accuracy in predicting premature thrombosis. CONCLUSIONS: A new algorithm has been described and its in vivo accuracy in estimating mean 'pressure from flow' has been confirmed. Two new variables and a new dedicated instrument BlueDop™ have been demonstrated in clinical use.

A novel approach of arteriovenous fistula formation in cultivation of an arm vein for use in infrainguinal surgical bypass grafting.

Autologous vein is preferable for use in lower limb arterial bypass rather than synthetic graft material. Suitable vein for grafting is often limited, particularly in patients who have had previous cardiac bypass grafting or varicose veins surgery. This case report describes the use of arteriovenous fistula formation to cultivate an arm vein of a suitable diameter for use in femorotibial bypassing.

Acute limb ischaemia due to focal brachial artery aneurysms complicating brachiocephalic arteriovenous fistula ligation: two recent case reports.

INTRODUCTION: True brachial artery aneurysms are rare, typically occurring secondary to trauma. In this report, we describe two recent cases of patients who presented acutely with upper limb ischaemia due to brachial artery aneurysms. Both patients presented many years after brachiocephalic arteriovenous (AV) fistula ligation in the ipsilateral limb. REPORT: Two male patients, aged 60 and 63 years, respectively, were seen acutely with symptoms of upper limb ischaemia. They had both undergone ligation of AV fistulae many years earlier having received functioning transplants. Subsequently, both patients were found to have true brachial artery aneurysms, which were bypassed in both instances using great saphenous vein grafts. DISCUSSION: Patients undergoing ligation of AV fistulae should receive interval surveillance imaging to detect potential aneurysmal dilatation of upper limb vessels. Little is known about the incidence of aneurysm formation after AV fistula ligation; given the increasing number of patients undergoing dialysis, and hence the burgeoning number of patients who may receive transplants, it is important that upper limb ischaemia is pre-empted by appropriate follow-up.

Is there an optimal interventional device for the salvage of thrombosed native angioaccess for hemodialysis?

The rescue of autogenous angioaccess for hemodialysis can be performed surgically or radiologically. For the latter, there is current debate as to whether a mechanical hydrodynamic device confers a clinical advantage over a rotational thrombectomy. The evaluated article describes a single center retrospective cohort study (275 procedures in 213 patients) assessing the observed outcomes of the AngioJet mechanical and hydrodynamic mechanism versus the rotational percutaneous thrombectomy device (PTD; Arrow-Trerotola). Outcomes measured were complications arising, as well as primary and secondary patency rates. The time taken to perform the PTD method was significantly shorter than for the AngioJet. Despite no significant difference seen between the two techniques for 6-month primary patency (43% PTD vs 45% AngioJet), secondary patency was significantly greater in PTD compared with AngioJet (74 vs 87%, p = 0.01). The authors conclude that the rotational mechanism device was faster and associated with a higher secondary patency rate.

What is happening in the world of vascular access? Research and innovations are flowing through.

Vascular access perfectly reproduces myointimal hyperplasia that can be found in coronary or peripheral arteries and has a major advantage that these other sites cannot match: it is quite superficial and not close to a major vital organ and also affects a population that will attend the hospital for dialysis on a very regular basis. It therefore appears obvious to try and develop a tool that will mitigate myointimal hyperplasia and that could later be tested on coronary or peripheral arteries. Over the past few years several trials have been organized and we are now at a stage where some results have become available.

Early cannulation grafts in straight axillo-axillary angioaccesses avoid central catheter insertions.

The need for early cannulation grafts exists to prevent use of central venous catheters. We report our experience in patients who had a straight axillo-axillary angioaccess. All patients who have undergone an early cannulation axillo-axillary angioaccess between 2008 and 2010 were reviewed. Fifteen patients had 16 procedures. Of these, eight were women and their mean age was 56. All patients had exhausted access options bilaterally. All had previous catheter insertions with either sepsis or jugular veins thrombosis. They all had an axillary artery to axillary vein angioaccess using an early cannulation graft. Flixene(®) (Atrium Medical, Hudson, NH, USA) was used in 10 cases, whereas Rapidax(®) (Vascutek Ltd., Renfrewshire, UK) in 6. In 12 cases, grafts were cannulated after 12 hours, in 4 after 24 hours (12 hours-8 days, mean 1.8 days). For Flixene(®) , mean delay to cannulation was 1.1 days, whereas 2.71 for Rapidax(®) (p < 0.05). Primary patency rates were 92.9% and 65.7% at 6 weeks and 1 year, respectively. Secondary patency rates were 92.9% and 83.5%. There was no significant difference in patency rates between grafts. Early cannulation grafts in a complex position are safe and efficient considering their patency and complication rates. It avoids using central venous catheters.

Retroesophageal internal jugular-to-internal jugular vein bypass for venous occlusion in a patient with complex hemodialysis access.

This report describes a right-hand dominant, self-dialyzing patient whose left brachiocephalic autogenous access was previously rescued for left brachiocephalic vein thrombosis with a bypass to the right internal jugular vein (IJV). After 1 year, the left IJV thrombosed, resulting in painful edema and venous dilatation. A retroesophageal IJV-IJV bypass was created, preserving the left brachiocephalic autogenous access.

Enormous brachio-cephalic arteriovenous fistula aneurysm after renal transplantation: case report and review of the literature.

Creation of arteriovenous fistulae provides readily available vascular access for haemodialysis in patients with end-stage renal disease. However, it is associated with various potentially serious complications if left unattended. We report a case of a 73-year-old male presenting with an enormous brachio-cephalic fistula aneurysm measuring 70-5.4 cm 20 years after successful renal transplantation. Despite attending regular renal outpatient clinic follow-up, this was only noticed as an incidental finding when the patient attended the emergency department after a fall that severely bruised his access. The patient subsequently underwent ligation with complete removal of the aneurismal fistula and discharged to a rehabilitation unit 3 days post-operatively. Systematic closure of an arteriovenous fistula should be considered in all patients after successful renal transplantation to avoid potentially catastrophic complications of an arteriovenous fistula. In patients in whom the closure of vascular access is contraindicated, it is crucial to regularly assess the status of any arteriovenous fistula when following up patients after renal transplantation.

High-output cardiac failure following insertion of right femoral artery to left femoral vein PTFE graft for haemodialysis: a case report.

Arteriovenous grafts used for hemodialysis can produce high-output cardiac failure as a result of shunting of blood through the dialysis access. The following case demonstrates that the problem can occur shortly after graft formation and improved with graft ligation. It caused haemodynamic compromise because of previously undiagnosed, underlying valvular heart disease. It also caused a diagnostic difficulty in the immediate postoperative period as it was mistaken for postsurgical hemorrhage.

Use of the femoral artery route for placement of temporary catheters for emergency haemodialysis when all usual central venous access sites are exhausted.

BACKGROUND: Urgent dialysis via a temporary central line may be impossible when all central veins are obstructed. METHODS: We report 10 patients (7 males and 3 females) over a 5-year period who lost all venous access sites, due to multiple peripheral venous thromboses with a superior vena cava obstruction or stenosis in 50%. These patients required urgent haemodialysis prior to general anaesthetic for a surgical intervention, but in all cases a traditional central venous line could not be used. They were therefore dialysed via a femoral artery catheter (FAC) before surgical rescue or creation of a more definite vascular access (VA). The median age of these patients was 64.7 years. None were suitable for peritoneal dialysis or urgent transplantation. Thirteen FACs (11F dual lumen dialysis catheter) were inserted into the common femoral artery. Both lumens were perfused continuously with heparinized saline (12 000 IU/24 h). All patients underwent a surgical procedure (rescue of previous access/creation of a new exotic one). First dialysis adequacy was assessed and compared to the rescued or new access. RESULTS: All patients had been on haemodialysis for a median period of 4.4 years. The mean number of previous access procedures was 17 (range 10-28). The duration of FAC use ranged from 1 to 12 days (mean 5 days). Dialysis adequacy was satisfactory for all patients. Seven patients had a complex vascular access formed and six had thrombectomy of their previous access. There were two complications related to FAC use, which were distal ischaemia and bleeding. Three patients died from access-related problems at 0, 4.6 and 15.0 months. Seven are still dialysed through their fistula or graft as outpatients with a mean follow-up of 14.0 months (range 0-50.9 months). CONCLUSION: Femoral artery dialysis is an effective means of haemodialysis as a method to bridge the gap before definitive vascular access formation when all other options have been exhausted.

Prosthetic axillary-axillary arteriovenous straight access (necklace graft) for difficult hemodialysis patients: a prospective single-center experience.

BACKGROUND: It is not uncommon for all usual upper limb autogenous access sites to fail, often in patients for whom neither peritoneal dialysis nor transplantation is an appropriate option. Axillary-axillary arteriovenous bypass grafts could be used as the last option before a thigh autogenous access even in case of unilateral central venous stenosis or obstruction. We describe our experience with this procedure in a series of patients. METHODS: A consecutive series of 18 patients for whom all possible arm accesses had failed and neither peritoneal dialysis nor transplantation was possible underwent a necklace graft formation over a 2.5-year period. All grafts implanted were 6 mm, internally reinforced prostheses made of expanded polytetrafluoroethylene (PTFE, Gore-Tex Intering Vascular Graft, W. L. Gore and Associates, Inc, Flagstaff, Ariz) anastomosed end to side the axillary artery and contralateral vein, and tunneled straight in the subcutaneous space before the sternum. All patients had bimonthly clinical examinations in which the thrill, bruit, skin, cannulation sites, and dialysis adequacy were reviewed. They also had at the same time a transonic assessment where graft flows and recirculation rates were measured. In case of low flow (<600 mL/min) or drop of 20% between two measurements or recirculation >5% a fistulogram was obtained, and an intervention was performed to restore patency. RESULTS: We operated on 10 males and 8 females; mean age was 55.1 years. The primary patency was 83% and 72.2%, and the secondary patency was 94.4% and 88.9% at 6 months and 1 year, respectively. Five successful surgical revisions were carried out for four clotted grafts and one post dialysis rupture. One surgical revision for thrombosis failed and one local infection lead to thrombosis and was not amenable to surgical revision. Three patients died of causes unrelated to their vascular access during the study period. CONCLUSION: The reasonable patency and minimal complications associated with these bypasses show that they are a valid option for complex patients. We advocate the use of this bypass in patients with exhaustion of all access possibilities in both arms with a patent superior vena cava, subclavian, and brachiocephalic veins. We also indicate it in case of unilateral central venous stenosis or obstruction with complete exhaustion of all other access possibilities on the contralateral side.

Is basilic vein transposition a real alternative to an arteriovenous bypass graft? A prospective study.

Basilic vein transpositions (BVTs) are considered to be superior to arteriovenous bypass grafts (AVGs). However, for the most part studies comparing BVTs to AVGs have been retrospective in design and without a set follow-up protocol. In this analysis, data were prospectively collected from patients with either a BVT or a brachio-axillary AVG. When all other native options were exhausted a BVT was performed if the vein had a diameter of 3 mm. All patients had bimonthly measurements of access inflow and recirculation using ultrasound dilution and were followed up for 2 years. Of 76 patients, 34 had a BVT and 42 an AVG (p > 0.05). BVT group: 12 were male, 22 female, the mean age was 62 and 26% were diabetic. AVG group: 22 were male, 20 female, the mean age was 57 and 56% were diabetic. The maturation delay was higher in the BVT group (6 weeks vs. 2 weeks). For the BVT and AVG groups, at 6, 12 and 24 months, respectively, primary patency was 90% vs. 76% (p < 0.05), 73% vs. 61% and 69% vs. 54% (p > 0.05). Assisted primary patency was 100% vs. 90% (p = 0.1201), 96% vs. 56% and 74% vs. 40% (p < 0.001). Secondary patency was 100% vs. 83%, 93% vs. 70% (p < 0.025) and 85% vs. 62% (p < 0.01). In the BVT group, 18 patients had 32 interventions for a total cost of $127,800, while in the AVG group, 27 patients had 54 interventions for a total cost of $227,300. This is the first prospective study to confirm that BVTs were cost effective and associated with better outcomes when compared with AVGs.

Does the surgeon's experience impact on radiocephalic fistula patency rates?

Establishing successful long-term hemodialysis access remains a major challenge. The primary aims of this study were to determine whether primary success and primary and secondary patency rates of a series of consecutive radio-cephalic fistulae (RCF) were affected by the experience of the surgeon. The secondary aims were to assess complications, and to compare results with patency rates from the literature. All native fistulae (AVF) created in our unit between January 1, 2002 and December 31, 2005 were analyzed retrospectively. The RCF were identified and divided into group A (RCF fashioned by the consultant surgeon), and group B (fashioned by the junior surgeons within the unit). Demographic characteristics, risk factors, primary success rate (patent fistula at discharge), and primary and secondary patency rates were compared between each group using chi-squared test. During this period, 552 AVF were created. Of the 195 RCF, there were 153 fistulae in group A and 42 in group B. Median follow-up was 22 months for both groups. There was no difference with regards to age, sex ratio, prevalence of diabetes, and cardiovascular disease. The primary success rate in group A and B was 94.2% and 81%, respectively (p < 0.01). Primary and secondary patency rates at 22 months were 80%, 93%* and 74%, 81%* in group A and B, respectively (*p < 0.025). Even within group B, these results compare very favorably with the published literature. These results suggest that the placement of a RCF should be performed by the most experienced member of a team dedicated to vascular access creation or at least under his supervision.

Intraoperative flow measurements are helpful in the treatment of high-inflow steal syndrome on a predialysis patient with a brachiocephalic fistula: a case report.

Distal revascularization and interval ligation (DRIL) is currently one of the mainstay treatments for severe steal syndrome. However, when high inflow is the underlying cause, this technique does not fully address the problem. Here, we describe the use of intraoperative flow measurements using transit time ultrasound technology to help identify the cause of steal syndrome in a predialysis patient (no transonic surveillance) with a brachiocephalic fistula, who then was treated successfully by inflow reduction surgery using a bovine ureter graft. We believe that inflow reduction might be superior to DRIL in treating steal syndrome caused by high inflow and that transit time ultrasound might be helpful when transonic treatment is not possible.