Arteriovenous access ischemic steal (AVAIS) in haemodialysis: a consensus from the Charing Cross Vascular Access Masterclass 2016

Long term outcomes of 'Christmas Tree' banding for haemodialysis access induced distal ischemia: A 13-year experience

BACKGROUND

The reduction in distal arterial flow following arteriovenous fistula (AVF) creation can cause a perfusion deficit known as haemodialysis access induced distal ischemia (HAIDI). Various techniques have been advocated to treat this difficult problem with varying success. We present the long-term outcomes following a novel banding technique.

METHODS

46 patients in this cohort from 2008 to 2021 underwent a novel banding procedure using a Dacron™ patch shaped with one slit-end and saw-tooth edges (resulting in a 'Christmas-tree' pattern) to provide a ratchet mechanism to progressively constrict the fistula outflow. Real-time finger perfusion pressure monitoring allowed an accurate reduction in AVF flow whilst increasing distal arterial perfusion pressure. Baseline characteristic were recorded and Kaplan-Meier survival curves were obtained to calculate the post-intervention primary, assisted primary and secondary patency.

RESULTS

29 patients presented with rest pain and 11 presented with tissue loss due to distal ischemia. The post-intervention primary access patency was 100%, 98%, 78% and 61% at 30, 60 and 180 days and 1 year respectively. Complete resolution of symptoms was achieved in 74% (n = 34) of patients and a partial response needing no further intervention was achieved in 11% (n = 5) of patients. A Youden index calculation suggested that digital pressures of 41 mm Hg or lower in an open AVF were highly sensitive for symptomatic hand ischemia whereas pressures greater than 65 mm Hg ruled out distal ischemia.

CONCLUSION

'Christmas-tree' banding with on table finger systolic pressures is not only an efficacious and durable method for treating HAIDI but also preserves fistula patency.

Small Caliber Distal Cephalic Veins Undergo Significant Dilation under Anesthesia and Can Successfully Be Used for Arteriovenous Fistula Creation

BACKGROUND

Successful arteriovenous fistula (AVF) maturation and use for dialysis is highly dependent on preoperative diameter. Small veins (<2 mm) exhibit high failure rates and are typically avoided. This study investigates the effects of anesthesia on the distal cephalic vein diameter as compared to preoperative outpatient vein mapping for the purpose of hemodialysis access creation.

METHODS

One hundred eight consecutive procedures for dialysis access placement met inclusion criteria and were reviewed. All patients received preoperative venous mapping and postanesthesia ultrasound mapping (PAUS). All patients received either regional and/or general anesthesia. A multiple regression was conducted to determine predictors of venous dilatation. The independent variables included both demographical and operative-specific variables such as the type of anesthesia. Outcomes of fistula maturation (successful cannulation and dialysis) were analyzed.

RESULTS

In this cohort, the mean preoperative vein diameter was 1.85 mm and the mean PAUS diameter was 3.45 mm, a 2.21× increase, with only 2 patient veins failing to increase in diameter. Smaller veins (<2 mm) exhibited significantly more dilation than larger veins after anesthesia (2.73 vs. 1.47×, P < 0.001). In the multiple regression analysis, smaller vein diameter was correlated with a significantly greater degree of dilation (P < 0.001). The degree of venous dilation was not affected by patient demographic-specific factors or by the type of anesthesia (regional block versus general) in the multiple regression analysis. 6 month follow-up data for fistula maturation was available for 75 of 108 patients. Small veins (<2 mm) on preoperative ultrasound matured at a similar rate as larger veins (90% vs. 91.4%, P = 0.833).

CONCLUSIONS

Small caliber distal cephalic veins experience a significant degree of dilation under regional and general anesthesia and can successfully be used for AVF creation. Consideration should be made to perform a postanesthesia vein mapping for all patients undergoing access placement despite preoperative venous mapping results.

Painless ulceration due to digital hypoperfusion ischaemic syndrome: case report and literature review

Digital hypoperfusion ischaemic syndrome (DHIS), also known as steal syndrome, is a well recognised serious complication of haemodialysis (HD) access creation. The clinical presentation varies from cyanosis to tissue loss due to necrosis or gangrene. In this article, we present a case of painless digital ulceration due to DHIS and provide a review of the literature. A 40-year-old-female presented with multiple painless digital ulcerations of the left hand. Her medical profile included atherosclerotic disease, hypertension, hyperparathyroidism and type I diabetes causing retinopathy, peripheral neuropathy, gastroparesis and end-stage renal disease (ESRD). Her ESRD required HD with the construction of a left-arm basilic vein transposition arteriovenous fistula (AVF). A year later, she developed intermittent, painless ulcerations of the left hand. A Doppler ultrasound confirmed the diagnosis of DHIS. The patient was treated with AVF ligation surgery. At six months postoperatively, she had near complete re-epithelialisation of her ulcers. This case is unique in that the patient did not have preceding pain, likely due to her underlying diabetic neuropathy. While DHIS in haemodialysis patients with AVF is well documented in literature, digital ulceration in this context is an advanced form of this condition. Early recognition of digital ulceration as a complication of DHIS may enable early intervention and prevent permanent damage.

MILLER Banding Procedure for Treatment of Dialysis Access-Related Steal Syndrome, Pulmonary Hypertension, and Heart Failure

A Minimally Invasive Limited Ligation Endoluminal-assisted Revision (MILLER) banding procedure has been used for treating patients with dialysis access-related steal syndrome (DASS) and high-flow vascular access-related pulmonary hypertension (PHT) and heart failure (HF).We performed a retrospective analysis of patients undergoing the MILLER procedure performed for DASS, HF, and PHT from our Vascular Access Database from September 2017 to October 2019. Outcomes included primary patency of banding, primary assisted patency, and secondary patency, using time-to-event analyses with Kaplan-Meier curves and life tables to estimate 6- and 12-month rates.A total of 13 patients (6 men and 7 women, mean age 60 ± 14 years) underwent the MILLER procedure, 6 patients for DASS and 7 patients for pulmonary hypertension and heart failure (PHT/HF). Technical success was achieved in all patients. The longest duration of follow-up was 28 months (median 12 months [IQR 7, 19]). One patient died at 1 month after the intervention due to stroke. One patient developed access thrombosis of the graft 3 days after the procedure. Repeat banding was required in 1 patient 8 months after the first procedure. The 6-month primary patency rate of banding following this procedure was 83% while the 12-month rate was 66%. The 6- and 12-month secondary patency rates were 87% and 75%, respectively.The MILLER procedure can be performed for DASS and PHT/HF with improvement of symptoms and good long-term patency rates. Additional interventions to maintain patency and efficacy are required on long-term follow-up.

Systolic finger pressures during an Allen test before hemodialysis access construction predict severe postoperative hand ischemia

OBJECTIVE

The Allen Test is a simple bedside method for determining hand perfusion. Earlier studies in hemodialysis (HD) patients found that an Allen Test before access construction did not predict hand ischemia later on. The study aimed to assess whether an Allen test combined with finger plethysmography before access surgery has a potential to predict the onset of severe hemodialysis access induced distal ischemia (HAIDI).

METHODS

Prior to the first access construction in chronic kidney disease (CKD) patients, systolic finger pressures (Pdig, mmHg) were obtained using plethysmography at rest and following serial compression of the radial and ulnar artery. A drop in Pdig (∂Pdig) was calculated as the difference between Pdig-rest and Pdig-compression. Severity of postoperative HAIDI was graded as suggested by a 2016 consensus meeting. Patients with a severe type of HAIDI (grade 2b-4, intolerable pain, invasive treatment required) were compared with controls not having HAIDI.

RESULTS

A total of 105 CKD patients (age 70 ±13, 65% males) receiving their first access between January 2009 and December 2018 in one center fulfilled study criteria. Ten patients (10%) developed severe HAIDI 14 ±5 months after access construction. Prior to access creation, all HAIDI patients demonstrated a radial or ulnar dominant hand perfusion pattern compared to just 57% in controls (p=.010). Compression resulted in an almost two-fold greater ∂Pdig in patients with severe HAIDI (51 ±8 mm Hg vs. 27 ±3 mm Hg, p=.005). A 40 mm Hg ∂Pdig cut-off value demonstrated optimal tests characteristics, (sensitivity 80%, specificity 77%, PPV 27%, NPV 97%) indicating a 10 times greater risk of developing severe HAIDI.

CONCLUSIONS

Finger plethysmography quantifying ∂Pdig during an Allen test prior to access creation may identify patients who have a substantially increased risk of developing severe hand ischemia following hemodialysis access surgery.

Ultrasound evaluation of dialysis access-related distal ischaemia

Dialysis access-related distal ischaemia is a rare yet potentially rather risky complication of haemodialysis angioaccess. Timely diagnosis is crucial to target both the goals of the access team: first of all to preserve the function of the hand ideally along with angioaccess patency. Unfortunately for some patients, urgent access ligation and central vein catheter insertion would be needed to save the hand. After a first clinical examination to determine the diagnostic suspicion, the ultrasound evaluation would provide nearly all the needed information to confirm the diagnosis and to determine the most appropriate procedure to rescue the patient from distal ischaemia. In some cases, photoplethysmography would help in the differential diagnosis of other non-ischaemic causes of similar signs and symptoms. Angiography would complete the preoperative evaluation for some.Dialysis access-related distal ischaemia would be briefly reviewed, and a deep description of the ultrasound examination tools and findings would be provided for a tailored therapeutic approach.

Monitoring the Patient Following Radio-Cephalic Arteriovenous Fistula Creation: Current Perspectives

Autogenous radial–cephalic direct wrist arteriovenous fistula (RC-AVF) in the non-dominant arm is the gold standard for dialysis vascular access. However, the RC-AVF non-maturation rate is significant (≃ 40%) due to an increasingly elderly and comorbid population incidence. A detailed identification of the biological cascade underlying arteriovenous fistula (AVF) maturation could be the key to clinical research aimed at identify the group of patients at risk of primary AVF failure. Currently, careful post-operative monitoring remains the most crucial aspect to overcome the problem of impaired maturation. Up to 80% of patients with immature RC-AVF have problems potentially solvable with early endovascular or surgical correction. Physical examination by experienced practitioners in conjunction with duplex ultrasound examination (DUS) can identify physical signs of non-maturation, understand the underlying cause, and drive for a tailored early planning to treat the complication. New approaches for the early assessment of AVF maturation are under study. Techniques to promote RC-AVF maturation performed through the administration of pre-or peri-operative drugs have missed up to now to prove an efficacy in improving fistula success. The new techniques tested after surgery appear to hold future promise for improving fistula maturation.

Skin perfusion pressure for predicting access-related hand ischemia following arteriovenous fistula surgery based on the brachial artery

BACKGROUND

Access-related hand ischemia (ARHI) is a major complication of arteriovenous fistula (AVF). This study aimed to assess the predictive efficacy of skin perfusion pressure (SPP) measurement for ARHI by examining the relationship between SPP and ARHI development and progression after AVF surgery.

METHODS

Twenty-five patients (16 men and 9 women) who underwent AVF surgery based on the brachial artery between January 2018 and December 2018 were included. The pre- and postoperative SPP values were measured on the day of surgery. ARHI occurrence and severity were measured within 3 days and at 6 months after surgery. Receiver operating characteristic curve analysis was used to evaluate the prediction model of ARHI, and the cutoff points for the calculated coefficients were determined.

RESULTS

There was a significant correlation between the occurrence of immediate ARHI and the SPP gradient (p = 0.024). An SPP gradient value >50 mmHg had sensitivity and specificity values of 53.85% and 91.67%, respectively, in predicting the occurrence of immediate ARHI. A postoperative SPP <48 mmHg was significantly correlated with the occurrence of 6-month ARHI (p = 0.005), with sensitivity and specificity values of 71.43% and 83.33%, respectively.

CONCLUSION

The SPP gradient and postoperative SPP values may be effective clinical predictors of ARHI occurring immediately and 6 months after surgery, respectively, with high specificity. These findings could allow clinicians to diagnose and begin early interventions to help prevent ischemic tissue damage in hemodialysis patients following AVF surgery.

Distal radial artery ligation for treatment of steal syndrome associated with radiocephalic arteriovenous fistula

We present a case of dialysis associated steal syndrome in a hemodialysis patient with left radiocephalic arteriovenous fistula that caused him severe rest pain. Angiography showed retrograde flow from the ulnar artery to the distal radial artery through a hypertrophied palmar arch. The problem was solved by surgical ligation of the distal radial artery leading to complete relief of patient symptoms without any notable complications.

Retrospective Analysis of 77 Hemodialysis Patients Shows No Cases of Steal Syndrome from Graft Taper Reduction

PURPOSE

To review the immediate flow response and incidence of steal syndrome after taper reduction of tapered dialysis grafts.

MATERIAL AND METHODS

This was a retrospective review of a quality assurance database of all hemodialysis access interventions performed between 2005 and 2017. It identified 77 patients who underwent a taper reduction procedure, involving angioplasty of the arterial limb of the graft and the arterial anastomosis for graft thrombosis/poor flow. A subset of patients underwent 5-, 6-, or 7-mm balloon taper reduction angioplasty coupled with intravascular direct flow measurement (n = 15 with 16 dialysis grafts). A two-tailed Wilcoxon matched-pairs signed-rank test was used to compare pre- and post-taper reduction flows. Mean duration of follow-up was 3.5 years (range, 0-12.5 years).

RESULTS

Mean access survival after taper reduction was 20.2 months (range, 0.10-94.4 months). Pre- and post-taper reduction access flows (mean Qb ± standard deviation) were 574 ± 315 ml/min and 929 ± 352 ml/min, respectively (P < .0001). The mean ratio of post- to pre-taper reduction flows was 1.6 (range, 1.1-10.2). No patients developed steal syndrome within 6 months after taper reduction.

CONCLUSIONS

Dialysis graft arterial anastomotic taper reduction did not result in the development of steal syndrome within 6 months. In the subset of patients who underwent flow measurements, taper reduction was associated with nearly a 2-fold improvement in access flow, which is a key predictor of access function.

Determining the incidence of needle-related complications in hemodialysis access: We need a better system

INTRODUCTION

Hemodialysis access complications are common. We hypothesize that many of these complications can be traced back to needle-related injury from routine cannulation practices or inadvertent cannulation injuries. We set out to compare the rates of hemodialysis access complications under prior and current diagnosis coding systems, determine the incidence of needle-related complications for hemodialysis access, and describe the association of needle-related complications and resulting interventions.

METHODS

Arteriovenous graft and arteriovenous fistula placements occurring in the first 6 months of 2014 and 2016 were identified in the United States Renal Data System Medicare claims data. Placements were followed until end of hemodialysis access life or end of the calendar year. Diagnoses and resulting interventions occurring during placement life were identified and mapped to needle-related complication terms.

RESULTS

Almost 30,000 placements for 27,000 patients were followed in each year, with 67% of all accesses placed being arteriovenous fistula and 33% arteriovenous graft. In both years, 75% of arteriovenous fistulae and arteriovenous grafts required one or more interventions. Stenosis and thrombosis were the most common complications diagnosed and treated (41% and 16%, respectively); however, potential needle-related complications accounted for 6% of this dataset.

DISCUSSION

International Classification of Diseases, 9th Revision, was inadequate for determining the incidence of specific hemodialysis access complications or needle-related complications. International Classification of Diseases, 10th Revision, introduced several more hemodialysis access diagnoses but is still subject to coding confusion and catch-all coding for a variety of common and otherwise well-defined complications, suggesting that the true incidence of needle-related complications is buried in the non-specific diagnosis codes. These findings mark the clear need for an improved diagnosis coding system that consistently represents all common hemodialysis access complications.

Severe hemodialysis access-induced distal ischemia may be associated with poor survival

BACKGROUND

Some hemodialysis patients develop hemodialysis access-induced distal ischemia due to insufficient loco-regional perfusion pressure and consequent poor arterial flow. We hypothesized that patients with severe hemodialysis access-induced distal ischemia had worse survival compared with patients with mild or no hemodialysis access-induced distal ischemia.

METHODS

This single-center retrospective observational cohort study included three groups of prevalent hemodialysis patients with an upper extremity vascular access between 2006 and 2018. Symptomatic patients had signs and symptoms of hemodialysis access-induced distal ischemia and low digital brachial indices (<60%) and were divided into a mild (Grade I-IIa) and a severe hemodialysis access-induced distal ischemia (IIb-IV) group. The control group consisted of hemodialysis patients without signs of hemodialysis access-induced distal ischemia with digital brachial indices ≥60%. Factors potentially related to 4-year survival were analyzed.

RESULTS

Mild hemodialysis access-induced distal ischemia-patients displayed higher digital brachial indices (n = 23, 41%, ±3) compared with severe hemodialysis access-induced distal ischemia-patients (n = 28, 24%, ±4), whereas controls had the highest values (n = 48, 80%, ±2; p < .001). A total of 44 patients (44%) died during follow-up. Digital brachial index (hazards ratio 0.989 [0.979-1.000] p = .046) was related to overall mortality following correction for presence of arterial occlusive disease (hazards ratio 2.28 [1.22-4.29], diabetes (hazards ratio 2.00 [1.07-3.72], and increasing age (hazards ratio 1.03 [1.01-1.06] as was digital pressure (hazards ratio 0.990 [0.983-0.998], p = .011). Overall survival was similar in mild hemodialysis access-induced distal ischemia and controls (2-year, 79% ±5; 4-year, 57% ±6, p = .818). In contrast, 4-year survival was >20% lower in patients with severe hemodialysis access-induced distal ischemia (2-year 62%± 10; 4-year 34% ± 10; p = .026).

CONCLUSION

Presence of severe hemodialysis access-induced distal ischemia may be associated with poorer survival in hemodialysis patients. Lower digital brachial index values are associated with higher overall mortality, even following correction for other known risk factors.

ASDIN white paper: Assessment and management of hemodialysis access-induced distal ischemia by interventional nephrologists

Although not common, hemodialysis access-induced distal ischemia is a serious condition resulting in significant hemodialysis patient morbidity. Patients with signs and symptoms suggestive of hand ischemia frequently present to the general and interventional nephrologist for evaluation. In order to care for these cases, it is necessary to understand this syndrome and its management. Most cases can be managed conservatively without intervention. Some cases requiring intervention may be treated using techniques within the scope of practice of the interventional nephrologists while other cases require vascular surgery. In order for the interventional nephrologists to evaluate and manage these cases in a timely and appropriate manner, practice guidelines are presented.

Preoperative assessment for percutaneous and open surgical arteriovenous fistula creation in patients for haemodialysis

Preoperative assessment prior to surgical arteriovenous fistulas (AVFs) including ultrasound-guided mapping has been shown to have beneficial effects on their immediate success as well as early outcomes. This has led to their wide acceptance and adoption however clinical practice criteria is variable and is reflected in variabilities in practice. When transposing this to percutaneously created endovascular AVFs (endoAVFs), variable preoperative assessment criteria could equally result in variable practice and potentially subsequent and expectant outcomes. We aimed to review literature on reported validated methodologies and workflows of preoperative assessment for surgical AVF creation as reported in highest levels of available evidence, specifically randomized controlled trials. Published practice recommendations and guidelines on best clinical practice as well as systematic reviews and meta-analyses of published studies were also reviewed. Data on practice methodology from identified trial publications and protocols was collated and a summative narrative synthesis was carried out which compared these methodologies to additional assessments that may be required when targeting assessment for percutaneous endoAVF formation, based on our units experience as part of an international multicentre trial. In this review we present a brief overview of published literature and guidelines and propose a unified and uniform workflow for preoperative assessment for surgical AVFs and endoAVFs to aide clinical and imaging practice.

A percutaneous endovascular technique for reducing arteriovenous fistula flow

Reduction of arteriovenous access flow is usually performed by tightening the inflow lumen through an open surgical procedure. A percutaneous endovascular approach can provide a precise and effective reduction of access flow without making a skin incision. After placing a vascular introducer sheath toward the inflow direction of an arteriovenous fistula, a small stent (5 mm diameter × 25 mm length) was deployed in the target area near the anastomosis. A second stent (10 mm × 60 mm) was then deployed inside the first stent, making a corset-shape constraint on the access flow. This newly described endovascular procedure was utilized to reduce the excessive flow of arteriovenous fistula in three patients. Deployment of the constrained stent-graft resulted in reducing the estimated access flow from 1900, 1600, and 1500 mL/min to 1100, 900, and 900 mL/min, respectively. Percutaneous endovascular placement of a constrained stent-graft can narrow the inflow lumen of arteriovenous access to a desired precise diameter of 5 mm and effectively reduce access flow over a long-term period.

Pseudo-aneurysm caused from banding failure

Background:

To present a case of banding failure with vessel wall erosion and pseudo-aneurysm creation caused by the suture.

Case report:

A 75-year-old male patient was operated for a high-flow fistula (>2 L/min). This was overall the third time that the patient was operated for the same indication since he started dialysis 5 years ago. Standard banding technique with perioperative flow measurements was used, and three separate Prolene sutures tied over 5 and 4.5 mm probes to achieve flow reduction. The operation was successful and first few weeks were uneventful. However, 5–6 weeks postoperatively, the patient felt locally an acute pain that lasted only few seconds and a voluminous aneurysm occurred progressively within the next few weeks. He was observed 2 months after the first operation where a recurrent high-flow fistula was diagnosed and ultrasound examination revealed that the sutures used for banding were into the vessel lumen while a pseudo-aneurysm had occurred at the same level. The patient was re-operated for excision of the aneurysm and flow reduction with tapering of the anastomosis.

Conclusion:

Under certain conditions, the suture used for banding may erode through the vessel wall and get into the lumen. This will result in recurrence of a high-flow fistula. While this has been previously described, the phenomenon was otherwise uneventful. In contrary, in the case presented herein, a potentially threatening pseudo-aneurysm has occurred.

Utility of perioperative skin perfusion pressure measurement for treatment of ulcers caused by arteriovenous access ischaemic steal

Arteriovenous access ischaemic steal is a serious complication following arteriovenous fistula (AVF) construction. The aim of treatment is to improve distal circulation without impairing the function of the fistula. Therefore, any repair should be performed with intraoperative monitoring. We report 2 cases of this disorder treated using perioperative measurement of skin perfusion pressure (SPP) for preoperative surgical planning and intraoperative guidance. A 73-year-old woman with a left cubital AVF developed gangrene of the tip of the left little finger. Arteriovenous access ischaemic steal was suspected. The SPP of the little finger was 18 mm Hg, which increased to 65 mm Hg after manual occlusion of the fistula. A 58-year-old woman with a left antebrachial AVF had gangrene of the tip of the left middle finger. The SPP was 19 mm Hg, and steal syndrome was suspected based on angiography and the SPP with manual occlusion of the fistula. In both cases, serial plication of the fistula was performed based on intraoperative perfusion pressure monitoring, leading to the successful resolution of the ischaemic steal syndrome. In both cases, haemodialysis could be continued through the repaired fistula.

The formulation and characterization of 3D printed grafts as vascular access for potential use in hemodialysis

Arteriovenous graft (AVG) failure continues to be a life-threatening problem in haemodialysis. Graft failure can occur if the implanted graft is not well-matched to the vasculature of the patient. Likewise, stenosis often develops at the vein-graft anastomosis, contributing to thrombosis and early graft failure. To address this clinical need, a novel ink formulation comprised of ACMO/TMPTA/TMETA for 3D printing a AVG was developed (ACMO-AVG), in which the printed AVG was biocompatible and did not induce cytotoxicity. The ease of customizing the ACMO-AVG according to different requirements was demonstrated. Furthermore, the AVG displayed similar mechanical properties to the commercially available arteriovenous ePTFE graft (ePTFE-AVG). Unlike ePTFE-AVG, the ACMO-AVG displayed excellent anti-fouling characteristics because no plasma protein adsorption and platelet adhesion were detected on the luminal surfaces after 2 h of incubation. Similarly, exposure to human endothelial cells and human vascular smooth muscle cells did not result in any cell detection on the surfaces of the ACMO-AVG. Thus, the present study demonstrates a newly developed 3D printing ink formulation that can be successfully 3D printed into a clinically applicable vascular access used for haemodialysis.

An arteriovenous graft that was successfully 3D printed with a novel printing ink formulation that displayed excellent mechanical and anti-fouling properties.

Novel use of infrared thermal imaging to predict arteriovenous fistula patency and maturation

OBJECTIVE

The arteriovenous fistula (AVF) is the preferred method of long-term haemodialysis. However, it has been shown to have a substantial rate of maturation failure. The formation of an AVF creates haemodynamic changes to blood flow in the arm with diversion of blood away from the distal circulation into the low pressure venous system, in turn, leading to thermal changes distally. In this study, we aimed to assess the novel use of infrared thermal imaging as a predictor of arteriovenous maturation.

METHODS

A prospective cohort study was conducted on 100 consecutive patients who had AVF formation from December 2015 to June 2016. Infrared thermal imaging was undertaken pre- and post-operatively on the day of surgery to assess thermal changes to the arms and to assess them as predictors of clinical patency and functional maturation.

RESULTS

For clinical patency, infrared thermal imaging was found to have a positive predictive value of 88% and a negative predictive value of 86%. For functional maturation, it was found to have a positive predictive value of 84%, a negative predictive value of 95%. In addition, it was shown to have superiority to the commonly used intra-operative predictor of thrill as well as other independent pre-operative patient factors.

CONCLUSIONS

Infrared thermal imaging has been found to be a very useful tool in accurately predicting fistula patency and maturation.

Arteriovenous access banding revisited

Purpose

The aim of this study is to validate the current applicability of arteriovenous access banding in high flow access (HFA) and/or haemodialysis access-induced distal ischaemia (HAIDI).

Methods

This retrospective study was conducted at the GEV (Grupo de Estudos Vasculares) vascular access centre. The clinical records of consecutive patients undergoing banding for HAIDI and HFA symptoms, between June 2011 and January 2015, were reviewed until April 2015. All vascular access patients’ consultation records and surgical notes were reviewed. We analysed and compared patients’ age, gender, comorbidities, symptoms and intraoperative ultrasound control. We defined technical failure as recurrence of symptoms, requiring new banding. Excessive banding, access thrombosis, rupture and false aneurysm development were registered as complications. Primary clinical success was defined as improvement of symptoms or effective flow reduction after banding, with no need for reintervention. If one reintervention was necessary, we have defined it as secondary clinical success.

Results

Overall, 119 patients underwent banding: 64 (54%) with HAIDI and 55 (46%) with HFA. The HAIDI group was significantly older (65 ± 13 years compared with 56 ± 22 years, p = 0.001) and had significantly greater number of patients with diabetes (56% vs 24%, p = 0.004). Primary success was achieved in 85 patients (71.4%) and the secondary success rate was 84.9%. Older age (p = 0.016) and intraoperative ultrasound control (p = 0.012) were significantly associated with primary success.

Conclusions

Our results do not corroborate the high incidence of thrombosis previously reported as associated with AV access banding and suggest that ultrasound control is crucial for preventing technical failure. The procedure was effective on both compared groups.