Steal in Hemodialysis Patients Depends on Type of Vascular Access

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.

The Role of Ultrasound Examination in the Assessment of Suitability of Calcified Arteries for Vascular Access Creation-Mini Review

Arterial calcifications are present in 20-40% of patients with end-stage kidney disease and are more frequent among the elderly and diabetics. They reduce the possibility of arterio-venous fistula (AVF) formation and maturation and increase the likelihood of complications, especially distal ischemia. This review focuses on methods for detecting arterial calcifications and assessing the suitability of calcified arteries for providing inflow before the construction of an AVF. The importance of a clinical examination is stressed. A grading system is proposed for quantifying the severity of calcifications in the arteries of the arm with B-mode and Doppler ultrasound exams. Functional tests to assess the suitability of the artery to provide adequate inflow to the AVF are discussed, including Doppler indices (peak systolic velocity and resistive index during reactive hyperemia). Possible predictors of the development of distal ischemia are discussed (finger pressure, digital brachial index, acceleration and acceleration time), as well as the outcomes of AVFs placed on calcified arteries. It is concluded that a noninvasive ultrasound examination is probably the best tool for a morphologic and functional assessment of the arteries. An arterial assessment is of utmost importance if we are to create distal radiocephalic AVFs in our elderly patients whenever possible without burdening them with futile surgical attempts.

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

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

Snuff-Box Versus Wrist Radiocephalic Arteriovenous Fistulas for Hemodialysis: Maturation Tend and its Affecting Factors

BACKGROUND

Thanks to its well proved long-term patency rates, native radiocephalic arteriovenous fistula remains the most commonly used vascular access type. Many articles had approached the criteria leading to a mature fistula. The aims of this work are to evaluate variables that may affect the maturation of distal fistulas and to determine if wrist fistulas have less risk of maturation failure than the snuff-box fistulas.

METHODS

We recorded all distal radiocephalic fistulas that had been created from January 2018 to February 2021. Epidemiological and clinical profile of patients, characteristics of performed fistulas and per and post-operative data were recorded and analyzed.

RESULTS

From January 2018 to February 2021, 165 upper limb vascular accesses for hemodialysis had been created including 47 (28.5%) distal radiocephalic fistulas. Among the latter, 39 (83%) fistulas were performed at the wrist and 8 (17%) at snuff-box area. There were 34 men (72.3%). Mean age was 67 years (37-87). Both types of fistulas had approximately an identic frequency of primary maturation failure (50% for radiocephalic versus 47.2% for snuff-box fistulas). Secondary maturation had been achieved in 9 fistulas. Patients with medical history of dyslipidemia, peripheral arterial disease (PAD), central catheter placement, and bad quality of vessels tend to develop an immature fistula.

CONCLUSIONS

No significant differences in maturation tend between snuff-box and wrist fistulas had been demonstrated. Thus, it seems reasonable to privilege the creation of the most distal fistulas allowing preservation of wrist fistulas as a second option in case of snuff-box fistulas maturation failure. However, selection of the most suitable cases for snuff-box fistulas creation, based on clinical and duplex ultrasound data, remains primordial.

The Results of The Interposition Graft-Technique in Treatment of High Flow Vascular Access

OBJECTIVE

High-flow (HF) vascular access (VA) is a fearsome condition potentially responsible for cardiac or pulmonary complications, steal syndrome and hand ischemia. The present study was conducted to report the results achieved in a group of patients undergoing interposition-graft technique to treat HF.

MATERIALS AND METHODS

An analysis of clinical, ultrasound and echocardiography data collected from the review of medical charts was performed. Flow reduction, complications and need for secondary interventions were investigated.

RESULTS

Among a total 498 hemodialysis access interventions performed during a 6-years period, 30 patients (n 15, 50% male, median age 63.5, range 42-91 years) presented with high-flow (median flow 1.9 L/min, range 1.5-4 L/min). 18 patients were asymptomatic (60%); 6 (20%) suffered from a severe distal hand ischemia; 5 (16.6%) developed signs of congestive heart failure and 1 patient (3.3%) presented with pulmonary hypertension. In twenty patients (66.7%) the access was preserved by the interposition of a 6 mm polytetrafluroethylene (PTFE) prosthesis. This approach was used as a primary flow reduction technique in 16 patients (80%) or the failure of a previously attempted procedure in 4 cases. No intraoperative complications were observed. Post-operative median VA flow was 1.1 L/min (range 0.900-2 L/min), with a median flow reduction of 0.770 L/min (range 0.100-2.8 L/min). At a median follow-up of 9 months (range 1-42), 95% (n 19) of patients were free from recurrences.

CONCLUSION

In treatment of HF-VA graft interposition demonstrated satisfactory results at the mid-term follow-up. More data are needed to affirm this technique as the preferential one.

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.

Abnormal preoperative digital brachial index is associated with lower 2-year arteriovenous fistula access patency

OBJECTIVE

The aim of the present study was to assess whether a single measurement of the digital brachial index (DBI; systolic finger pressure/systemic pressure ratio), reflecting the arm's circulation, was associated with access patency in patients with severe chronic kidney disease scheduled for arteriovenous fistula (AVF) creation.

METHODS

A bilateral DBI was obtained using digital plethysmography just before construction of the patient's first AVF from January 2009 to December 2017 at one center. A DBI of 80% to 99% was considered normal, and a DBI of <80% (low) or DBI of ≥100% (high) were considered abnormal. DBI values ipsilateral to the AVF were used for analysis. The primary and secondary access patency rates were calculated using reported standards and compared using standard statistical techniques.

RESULTS

Data sets of 163 patients were obtained (69 women; age, 71 ± 12 years). The median follow-up was 40 weeks (range, 0-104 weeks; follow-up index, 99% ± 1%). Patients with abnormal preoperative DBI values had lower 2-year primary patency rates (low DBI, 25% ± 11%; high DBI, 28% ± 6%; normal DBI, 49% ± 8%; P = .018). After correction for age, sex, hypertension, diabetes mellitus, cardiovascular disease, smoking status, and a history of ipsilateral central venous catheter use, an adjusted model demonstrated that abnormal DBI values conferred an increased risk of primary patency failure (low DBI [<80%]: hazard ratio [HR], 2.25; 95% confidence interval [CI], 1.13-4.48; high DBI [≥100%]: HR, 1.74; 95% CI, 1.06-2.85; P < .030 for both). Patients with a low preoperative DBI had also had diminished secondary patency (HR, 2.86; 95% CI, 1.08-7.59; P = .035). In contrast, the diameters of the outflow veins did not determine access patency.

CONCLUSIONS

Patients with abnormal DBI values before AVF construction for hemodialysis had lower 2-year access patency rates compared with patients with a normal DBI. Plethysmographic finger measurements might have a role in the preoperative counseling of patients with severe chronic kidney disease requiring an AVF.

A modified banding technique: experience of a center

BACKGROUND

A well-functioning vascular access is vital to patients on regular hemodialysis. Banding the access is indicated in high-flow-associated steal syndrome. It allows for the reduction of access flow while maintaining distal limb perfusion. Nonetheless, this procedure has some limitations as it can cause hemorrhage, infection, aneurysm formation, thrombosis of access in cases of overbanding, or otherwise insufficient reduction of vascular flow. Other surgical techniques to achieve the same benefit would be useful.

METHODS

We performed a modified banding technique without endovascular placement of the angioplasty balloon, which is a viable alternative to other techniques. This surgery was performed in patients on chronic dialysis with steal syndrome. Pre- and post-operative access flows were measured and resolution of symptoms was recorded. Primary patency rate was defined as the intervention-free access survival from the operative time.

RESULTS

We verified that this technique allowed for access flow reduction in all our six patients, with total resolution of symptoms in all patients. Primary patency rate at 12 months was 100%. No major complications were noted during our follow-up.

CONCLUSIONS

This technique allows for correction of high-flow arteriovenous fistulas in an efficient and safe way, and can be a viable alternative to other banding procedures.

Avoiding hemodialysis access-induced distal ischemia

Timely creation and maintenance of a safe and reliable vascular access is essential for hemodialysis patients with end-stage renal disease. Hemodialysis access-induced distal ischemia (HAIDI) is a recognized complication of arteriovenous fistulas and grafts that may result in serious or even devastating consequences. Avoiding such complications is clearly preferred over treatment of HAIDI once established. Proper recognition of patients at increased risk of HAIDI includes careful pre-operative evaluation of the patient's medical and surgical history along with physical examination and imaging to determine a plan for creating a functional permanent access while minimizing the risk of distal ischemia. Our aim is to review identifying characteristics of individuals at risk of HAIDI and provide recommendations regarding pre-operative assessment. Vascular access options and techniques are suggested for establishing a functional vascular access without distal ischemia for such patients.

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.

Digital pressure in haemodialysis patients with brachial arteriovenous fistula

Background & objectives

: The pathophysiological mechanisms involved in distal pressure changes following arteriovenous fistula (AVF) creation in patients with end-stage renal disease (ESRD) are not completely understood. This study was aimed to assess digital pressure changes post-AVF creation and to identify the factors that might influence these changes in ESRD patients.

Methods

: In this prospective study, 41 patients with ESRD underwent AVF creation. Basal digital pressure (BDP), digital brachial index (DBI), calcium, phosphorus and blood urea levels were assessed preoperatively. BDP, DBI, vein and artery diameters, and AVF blood flow were also evaluated at one and two month(s) post-AVF creation.

Results

: Mean BDP significantly decreased from 131.64±25.86 mmHg (baseline) to 93.15±32.14 and 94.53±32.90 mmHg at one and two months post-AVF creation, respectively (P <0.001). Mean DBI significantly decreased one month post-AVF creation versus baseline (0.70±0.18 vs. 0.89±0.17 mm, P <0.001) and remained similar at two versus one month(s) postoperatively (0.70±0.23 vs. 0.70±0.18 mm). At both postoperative timepoints, no correlation between DBI decrease and increased artery and vein diameters or fistula blood flow was observed. Mean DBI difference between patients with previous ipsilateral access versus those without was not significant from pre to one month postoperatively. No correlation was observed between baseline phosphorus, calcium and blood urea nitrogen and DBI changes.

Interpretation & conclusions

: Our findings suggest that decrease in distal pressure following AVF creation may not be influenced by the arterial remodelling degree, vein diameter or fistula flow. In uraemic patients, those with low calcium and/or increased phosphorus, no association between these parameters and DBI changes could be observed.

Skin Microcirculatory Changes in Relation to Arteriovenous Fistula Maturation

Maturation of arteriovenous fistula (AVF) involves complex vascular remodeling. In this study, we evaluated the changes of skin microvascular perfusion over the extremity with AVF maturation using the laser Doppler fluximetry (LDF). A total of 45 patients with chronic kidney disease, Stages IV-V, were included; they had undergone AVF creation from July 2014 to June 2016 at our institute. The measurement of skin microvascular perfusion was accomplished proximal and distal to the fistula anastomosis site: pre- and post-operative day 1, week 2, week 6, and week 12. Thirty-two patients with mean age of 55.6 had achieved AVF maturation. There were 40.6% radial-based and 59.4% brachial-based AVF. There was a 32.8% reduction of mean skin perfusion distal to the fistula by day 1 compared to the baseline perfusion; however, perfusion increased 47% by week 2 compared to day 1 and no dramatic change was subsequently noted. There was an increase of mean skin perfusion, proximal to fistula anastomosis, over 12 weeks with 35.8% at day 1 from the baseline. However, the changes of the mean skin perfusion were not statistically significant. There was no significant relation of skin perfusion changes with the type of fistula, diabetes mellitus, hypertension, and hyperlipidemia. LDF successfully detected the subclinical change of skin microvascular perfusion in relation to AVF creation. Reduction of skin perfusion distal to the fistula suggests that in patients with existing perfusion inadequacy of extremities, they may experience ischemic symptoms as early as day 1 postoperation, and require close monitoring for distal limb ischemic-related complications.

Spanish Clinical Guidelines on Vascular Access for Haemodialysis

Vascular access for haemodialysis is key in renal patients both due to its associated morbidity and mortality and due to its impact on quality of life. The process, from the creation and maintenance of vascular access to the treatment of its complications, represents a challenge when it comes to decision-making, due to the complexity of the existing disease and the diversity of the specialities involved. With a view to finding a common approach, the Spanish Multidisciplinary Group on Vascular Access (GEMAV), which includes experts from the five scientific societies involved (nephrology [S.E.N.], vascular surgery [SEACV], vascular and interventional radiology [SERAM-SERVEI], infectious diseases [SEIMC] and nephrology nursing [SEDEN]), along with the methodological support of the Cochrane Center, has updated the Guidelines on Vascular Access for Haemodialysis, published in 2005. These guidelines maintain a similar structure, in that they review the evidence without compromising the educational aspects. However, on one hand, they provide an update to methodology development following the guidelines of the GRADE system in order to translate this systematic review of evidence into recommendations that facilitate decision-making in routine clinical practice, and, on the other hand, the guidelines establish quality indicators which make it possible to monitor the quality of healthcare.

How arteriovenous grafts could help to optimize vascular access management

A one-size-fits-all approach to vascular access for dialysis may be prejudicial. Arteriovenous fistulae (AVF) have high primary failure, failure to mature rate, and late-stage complications making them unsuitable choice for many patients. Aging of population with chronic kidney disease (CKD) coupled with venous injury during CKD stages depletes suitable superficial veins for AVF creation. The National Institutes of Health consortium demonstrated the difficulty in attaining a functional AVF in hemodialysis patients. Recognition of flaws in AVF and the quest to reduce catheter use bring to the fore the benefits of arteriovenous grafts (AVG). Advances in catheter technologies, flow, care, and antibiotic locks have resulted in significant improvement in catheter-related infections. However, widespread recognition of catheter-related complications like central vein stenosis, metastatic infections, and exhaustion of venous access sites preclude their being a viable alternative to AVF, furthering the need to explore AVG as a substitute. Placement of "early cannulation" AVG is a catheter sparing option in patients who are likely to have inadequate fistula maturation. Advances in biohybrid technology and tissue-engineered grafts are providing a robust opportunity to develop biocompatible graft materials with minimal tissue reactivity and thrombogenicity. Xenografts (bovine carotid artery grafts) are proving to be comparable and, in many cases, better than conventional polytetrafluoroethylene material. Older age, dialysis dependence, and smaller vein size are related to the appropriateness of AVG creation. An individualized approach in selecting optimal upper extremity vascular access option using patient-specific factors while incorporating the benefits of an AVG would greatly aid in achieving low catheter usage in the dialysis population.

Decrease of muscle strength in vascular access hand due to silent ischaemia

Background:

Creation of vascular access leads to considerable local haemodynamic changes with decreased hand perfusion. Distal limb tissues then represent a model of hand ischaemia effect on muscles. The aim of our study was to investigate how the presence of vascular access influences the hand muscle strength in end-stage renal disease patients.

Methods:

We included 52 chronically haemodialysed patients with upper limb access without clinical signs of hand ischaemia. Muscle strength was evaluated by dynamometry. Finger pressure was measured on the second and fourth fingers and averaged for further analysis. Thenar tissue oxygenation (rSO2) was analysed using near-infrared spectroscopy. All examinations were performed in both the hands. Basic laboratory analysis was added. Data were processed with unpaired t-test and correlation analysis.

Results:

Hands with dialysis access had lower values of handgrip strength (54.2 ± 29.1 lbs vs 48.6 ± 23.4 lbs, p = 0.0006), systolic finger pressure (127.1 ± 32.0 mmHg vs 101.4 ± 31.6 mmHg, p < 10−8) and of thenar rSO2 (45.8% ± 12.9% vs 42.5% ± 13.3%, p = 0.002). Muscle strength (handgrip) was directly related to the thenar oxygenation ( r = 0.36; p = 0.014) and to the finger systolic pressure ( r = 0.38; p = 0.007) on the access extremity. On the extremity without dialysis access, handgrip strength was inversely related to patient’s age ( r = −0.41, p = 0.003), dialysis vintage ( r = −0.32, p = 0.02) and red cell distribution width ( r = −0.37, p = 0.01).

Conclusion:

The presence of dialysis access leads to the decrease of finger pressure, oxygenation, and also muscle strength even in the absence of clinically overt hand ischaemia. All these parameters are interrelated. This study underlines the consequences of inadequate muscle perfusion.

Flow Interruption of the Distal Radial Artery: Treatment for Finger Ischemia in a Matured Radiocephalic AVF

Purpose

To establish an effective approach for diagnosis and treatment of hand ischemia in matured radiocephalic arteriovenous fistulae (AVF).

Methods

One hundred and fifty end-stage renal disease patients (4% of our practice) presented to our outpatient vascular access facility complaining of a range of symptoms including coldness, numbness and pain in the fingers indicative of ischemia due to steal syndrome. In 15 patients the symptoms of steal syndrome were limited to the fingers, sparing the hand. Physical examination was indicative of steal syndrome caused by shunting of blood from the ulnar artery via the palmar arch, away from the fingers and into the fistula. To confirm the diagnosis, angiography was performed which demonstrated retrograde flow in the distal radial artery (DRA), a hypertrophied palmar arch, and a patent hypertrophied ulnar artery. Ischemia was treated with DRA flow interruption. Transcatheter coil embolization of the DRA (10 patients) was preferred because it proved to be a quick, safe and effective technique. Whenever embolization was not possible ligation of the DRA was performed in accordance with accepted surgical literature (five patients).

Results

DRA flow interruption was effectively accomplished by either ligation or coil embolization in all cases. All patients had symptomatic improvement. Complete symptom resolution was experienced by 100% (10/10) of patients who received DRA embolization and by 3/5 patients who required ligation. The average follow-up period was 9 months. There were no complications during the procedure or during the follow-up period.

Conclusion

Diagnosis using physical examination, angiography and treatment with embolization or ligation of the DRA can be performed with great success in an outpatient setting.

Surgical Banding for Refractory Hemodialysis Access-Induced Distal Ischemia (HAIDI)

Hemodialysis patients may develop distal ischemia in an extremity harboring a functioning arteriovenous access (AVA). Surgery is indicated if conservative treatment including catheter-based therapies fails. The role of surgical banding for refractory hemodialysis access-induced distal ischemia (HAIDI) is systematically reviewed (n=39 articles). If banding is executed without an intraoperative monitoring tool (“blind”), or guided by finger pressures only, clinical success and access patency rates are low (<50%). In contrast, banding is clinically successful when access flow is monitored during the operative procedure, with excellent long-term patency of banded AVA's (97%, 17 ± 3 months). Banding is the method of choice in HAIDI patients with a normal or high access flow (>1.2 l/min) provided that flow and distal perfusion are closely monitored intraoperatively.

Dialysis-associated steal syndrome (DASS)

INTRODUCTION

In this article, we will review the clinical symptoms of dialysis access steal syndrome (DASS), evaluation, treatment options, and our approach and treatment algorithm.

METHODS

We reviewed the literature discussing different aspects of DASS including its epidemiology, pathogenesis, clinical presentation, evaluation and management options.

RESULTS

DASS is the most dreaded complication of access surgery. Although the incidence is low, all providers caring for dialysis patients should be aware of this problem. Symptoms can range from mild to limb threatening. Although various tests are available, the diagnosis of DASS remains a clinical one and requires thoughtful management to have the best outcomes.

CONCLUSIONS

Multiple treatment options exist for steal. We present diagnostic evaluation and management algorithm.

Prosthetic Hemodialysis Access-induced Distal Hand Ischemia and its Contributors in Diabetics

Avoidance of hand ischemia in the construction of prosthetic access for hemodialysis in diabetics that have no suitable vein for arteriovenous fistula is appreciated. Taper type may be an appropriately matched conduit to prevent its occurrence. This is a prospective controlled trial of 38 selected diabetics requiring hemodialysis, who were referred to our clinic during a period of 6 months. The aim of the study was to evaluate the efficacy of tapered grafts in preventing distal hand hypoperfusion and determining its most likely contributors. In 18 intervening cases, taper 4 mm × 7 mm and in twenty cases (control group), standard 6 mm polytetrafluoroethylene as straight Brachial-Axillary access was used. Graft flow rates, artery and vein diameters, and mean arterial pressure were included for evaluation. Within the control group, 11 patients (55%) (7 cases Grade 1, 3 Grade 2, 1 Grade 3) and in intervening group, 2 cases (11%) (Grade 1, Grade 3) developed Steal syndrome. There was no significant difference in the mean flow rates (P = 0.82). Increased risk of distal hypoperfusion was observed in the control group when flow rates were more than 1000 ml/min. Arterial diameters (P = 0.011) and mean arterial pressure (P = 0.05) were found to be important contributing factors. Taper grafts causes reduced incidence of distal hand hypoperfusion. When artery diameter was <6 mm and mean arterial pressure lower than 100 mmHg and the index (brachial artery diameter × mean arterial pressure) was under 500, distal hand ischemia occurred in standard and tapper type. We therefore recommend selective usage of taper grafts in diabetics with diminished distal hand pulses, considering the contributing factors when fistula first is not feasible.

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

Arteriovenous access ischaemic steal (AVAIS) is a serious and not infrequent complication of vascular access. Pathophysiology is key to diagnosis, investigation and management. Ischaemia distal to an AV access is due to multiple factors. Clinical steal is not simply blood diversion but pressure changes within the adapted vasculature with distal hypoperfusion and resultant poor perfusion pressures in the distal extremity. Reversal of flow within the artery distal to the AV access may be seen but this is not associated with ischaemia in most cases.

Terminology is varied and it is suggested that arteriovenous access ischemic steal (AVAIS) is the preferred term. In all cases AVAIS should be carefully classified on clinical symptoms as these determine management options and allow standardisation for studies.

Diabetes and peripheral arterial occlusive disease are risk factors but a ‘high risk patient’ profile is not clear and definitive vascular access should not be automatically avoided in these patient groups.

Multiple treatment modalities have been described and their use should be directed by appropriate assessment, investigation and treatment of the underlying pathophysiology. Comparison of treatment options is difficult as published studies are heavily biased. Whilst no single technique is suitable for all cases of AVAIS there are some that suit particular scenarios and mild AVAIS may benefit from observation whilst more severe steal mandates surgical intervention.

Vascular access should be tailored to the patient

A cornerstone of hemodialysis treatment is the creation of a functional and durable dialysis vascular access. Every patient with chronic kidney disease should have a plan of renal replacement therapy and access site protection. Factors having a crucial impact on vascular access selection include age, comorbidity, vessel quality, prognosis, dialysis urgency, and surgeon's preferences. Our medical group have reviewed these factors in our patients and, based on recently published data, developed a clinical decision tree for dialysis access in the chronic kidney disease patient. Vascular access care should be patient-centered with the aim to maximize patient survival without loss of vascular access options; and not focused only the primary patency rates of dialysis access procedures.

A Systematic Review and Meta-Analysis of Circulating Biomarkers Associated with Failure of Arteriovenous Fistulae for Haemodialysis

BACKGROUND

Arteriovenous fistula (AVF) failure is a significant cause of morbidity and expense in patients on maintenance haemodialysis (HD). Circulating biomarkers could be valuable in detecting patients at risk of AVF failure and may identify targets to improve AVF outcome. Currently there is little consensus on the relationship between circulating biomarkers and AVF failure. The aim of this systematic review was to identify circulating biomarkers associated with AVF failure.

METHODS

Studies evaluating the association between circulating biomarkers and the presence or risk of AVF failure were systematically identified from the MEDLINE, EMBASE and Cochrane Library databases. No restrictions on the type of study were imposed. Concentrations of circulating biomarkers of routine HD patients with and without AVF failure were recorded and meta-analyses were performed on biomarkers that were assessed in three or more studies with a composite population of at least 100 participants. Biomarker concentrations were synthesized into inverse-variance random-effects models to calculate standardized mean differences (SMD) and 95% confidence intervals (CI).

RESULTS

Thirteen studies comprising a combined population of 1512 participants were included after screening 2835 unique abstracts. These studies collectively investigated 48 biomarkers, predominantly circulating molecules which were assessed as part of routine clinical care. Meta-analysis was performed on twelve eligible biomarkers. No significant association between any of the assessed biomarkers and AVF failure was observed.

CONCLUSION

This paper is the first systematic review of biomarkers associated with AVF failure. Our results suggest that blood markers currently assessed do not identify an at-risk AVF. Further, rigorously designed studies assessing biological plausible biomarkers are needed to clarify whether assessment of circulating markers can be of any clinical value. PROSPERO registration number CRD42016033845.

Creating Arteriovenous Fistulas using Surgeon-performed Ultrasound

Purpose

An arteriovenous fistulas (AVF) is the preferred vascular access for hemodialysis and is associated with lower mortality, morbidity and cost when compared with grafts and particularly with central venous dialysis catheters. This study reviews a series of new patients where an autogenous access was constructed for each individual utilizing surgeon-performed ultrasound (SP-US).

Methods

Consecutive new patients referred for a permanent vascular access during an 11-year period were retrospectively reviewed. In addition to physical examination, each patient underwent SP-US evaluation for preoperative vessel mapping and post-operative evaluation for access maturation. SP-US was also used in the evaluation of access dysfunction in mature AVFs.

Results

We identified 1874 patients. Ages were 8-94 years (mean 60 years). Of these, 51% were female and 59% were diabetic; 33% had previous failed access operations. Follow-up was 3-127 months (mean 23 months). An autogenous access was constructed for each individual. No grafts were used. Direct AVFs were constructed in 1240 (66%) patients and 634 (34%) individuals required a transposition or translocation procedure. Primary and cumulative patency rates were 60.0% and 93.0% at 12 months and 47.3% and 90.2% at 24 months, respectively. AVF arterial inflow was most commonly supplied by the proximal radial artery (67%).

Conclusions

Creating a functional autogenous vascular access is possible for most patients. No grafts were used in this series of 1874 consecutive new patients. Important elements for success included SP-US evaluation, utilization of the many vascular access options available, establishing radial artery AVF inflow when feasible, and prompt intervention when indicated.

Access ligation in transplant patients

Access surgeons will encounter patients with functioning transplants who want to lose their fistula, and every dialysis unit sees patients returning after a failed kidney transplant for whom an old fistula is a readily available lifeline. The decision is straightforward in patients with perfectly functioning transplants and disabling complications of their fistula, or in patients with failing transplants and a good fistula. The challenge is to make this decision in patients with good transplant function and an asymptomatic fistula. Despite improvements in one-year survival of renal grafts, the long-term graft survival has improved modestly. This means about half of the patients with a successful kidney transplant will return to dialysis within 10 years. Use of recently developed risk calculators, based on clinical parameters, may help in the decision process. A high flow fistula can lead to heart failure but most fistulae are well tolerated in asymptomatic patients and the effects of closure of the AVF on the heart are modest. Recent evidence suggests that there may be benefits of a functioning AVF that may need to be considered in this decision process. This article reviews the literature and comes to pragmatic recommendations of what to do with this conundrum.

The snuffbox fistula should be preferred over the wrist arteriovenous fistula

OBJECTIVE

The snuffbox arteriovenous fistula (SBAVF) is the most distal native vascular access. Although published data show a favorable outcome, the SBAVF is not strongly recommended by the guidelines. The present study compared the patency of SBAVFs and wrist AVFs (WAVFs).

METHODS

All 416 AVFs created by the same nephrologist from March 2006 to October 2014 were reviewed. From 416 procedures, 47 SBAVFs and 77 WAVFs with vessels suitable for a SBAVF were selected.

RESULTS

Although vessel diameters used for construction of the SBAVFs were smaller than those used for WAVFs, the outcome of vascular access was similar. At 18 months, primary patency was 72% for SBAVF and 65% for WAVF (P = .48), and secondary patency was 93% for SBAVF and 94% for WAVF (P = .89).

CONCLUSIONS

In our experience, a SBAVF performs as well as a WAVF up to 18 months after creation. We suggest favoring SBAVF, especially in young patients without comorbidities, as the primary vascular access.

Neurological Complications of Vascular Access

Neurological problems are common in patients undergoing haemodialysis. Over 60% of patients will suffer from symptoms of underlying polyneuropathy due to uraemia or diabetes. Others will have subclinical disease demonstrable by nerve conduction studies.

Nerve injury following haemodialysis access surgery is underreported. However, sensory nerve lesions are probably common after most vascular access procedures but are rarely debilitating.

Nerve compression syndromes such as carpal tunnel and ulnar compression syndromes are common, especially in patients who have been on dialysis for some years and at least some of these are related to or exacerbated by the access. Recognition is essential as they are eminently treatable by decompression surgery. Tourniquet use appears to be safe for carpal tunnel or ulnar nerve decompression surgery.

Ischaemic monomelic neuropathy (IMN) is rare but follows a period of ischaemia during or as a result of access surgery, most commonly to construct a brachial arteriovenous fistula or graft. It is characterised by intense pain, out of proportion to any ischaemia, involves all of the upper limb nerves and may progress to involve the motor nerves eventually resulting in a useless clawed hand. It requires prompt treatment of any residual ischaemia after access creation, if necessary by access ligation, as in the established syndrome, like the even rarer complication of reflex sympathetic dystrophy, it is very difficult to offer any useful treatment other than symptomatic relief and physiotherapy.

One-Year Efficacy of the RUDI Technique for Flow Reduction in High-Flow Autologous Brachial Artery-Based Hemodialysis Vascular Access

Purpose

Flow reduction is advised in hemodialysis (HD) patients with a high-flow (>2 L/min) arteriovenous fistula (AVF). The revision using distal inflow (RUDI) technique is based on the premise that access flow is attenuated once inflow is provided by a smaller caliber forearm artery. Aim of the study was to evaluate the efficacy of RUDI during a 1-year follow-up.

Methods

All HD patients undergoing a RUDI operation using a greater saphenous vein (GSV) or a basilic vein (BaV) interposition for a high-flow access (HFA, >2 L/min) during a 3.5-year time period were included. Serial access flow, percentage of freedom from recurrent high flow and complications were determined.

Results

A total of 19 HFA patients were studied (11 males, age 55 ± 3 years). All AVFs were brachial artery based (brachiocephalic, n = 14; brachiobasilic, n = 5). RUDI immediately reduced access flow by almost 2 L/min (3,080 ± 200 to 1,170 ± 160 mL/min (p = 0.001)). Access flows at 1, 6 and 12 months were 1,150 ± 160, 1,460 ± 200 and 1,580 ± 260 mL/min, respectively. Postoperative complications included insufficient flow reduction (n = 1, BaV) and occlusion requiring revision (n = 1, GSV). Recurrent HFA occurred three times (n = 2 BaV, n = 1 GSV). Access flows were significantly (p<0.05) higher in the BaV group compared to the GSV group.

Conclusions

RUDI effectively reduces access flow in a brachial artery-based high-flow HD vascular access. A flow-reducing effect is sustained at 1-year follow-up in most patients. GSV is preferred as an interposition graft compared to a BaV.

Preferred strategy for hemodialysis access creation in elderly patients

BACKGROUND

Adequate functioning vascular access is the key to successful hemodialysis. The use of an autologous arteriovenous fistula (AVF) is advised because of good long-term patency and a low incidence of complications. However, the number of patients with AVFs is declining because of the change in the demography of the dialysis population, with increasing numbers of very old patients with multiple comorbidities.

METHODS

In this vignette an elderly patient is described with calcified distal arteries and a small cephalic vein who is referred at a late stage for access creation. The results and performance of different types of vascular access (AVF; arteriovenous graft; central vein catheter), in relation to late referral and patient demographics, are described. In addition, patient morbidity and mortality versus the type of access are discussed.

CONCLUSIONS

The patient described in this vignette appears to be unsuitable for the creation of a forearm AVF because of calcified distal arteries and a small cephalic vein. The risk of non-maturing autologous AVFs is high in elderly patients and this observation might justify the use of early stick grafts. High risk patients may benefit from permanent central vein catheters.

Hemodialysis access-induced ischemia is not related to configuration and access flow rates of upper arm arteriovenous fistulas at the elbow

BACKGROUND

The purpose of the study was to find a relationship between the configuration of autogenous upper arm arteriovenous fistulas (AVFs) at the elbow and high access flow rates.

METHODS

Forty-seven patients with well-functioning autogenous upper arm AVFs at the elbow were included. The configuration of the AVF and access flow rate was determined by duplex scanning.

RESULTS

Hemodialysis access-induced distal ischemia scores and access flow rates were comparable in AVFs with 1 or 2 efferent veins (1829.9 ± 1121.3 mL/min, range [400-5000] vs. 1988.5 ± 1324.5 mL/min, range [130-5000]; P = 0.61). The basilic vein had statistically significant larger diameters than the cephalic vein (8.1 ± 2.7 mm, range [2.7-11.0] vs. 5.8 ± 2.5 mm, range [3.8-13.0]; P = 0.02), but no statistically significant difference in flow rates were observed (1884.5 ± 889.0 mL/min, range [824-3600] vs. 1130.0 ± 1258.4 mL/min, range [400-5000]; P = 0.53). Access flow rates were higher in AVFs with the brachial artery as afferent artery than when the radial artery was used (1909.5 ± 1273.2 mL/min, range [550-5000] vs. 1188.6 ± 642.7 mL/min, range [130-2800]; P = 0.02).

CONCLUSIONS

There is no difference in access flow rates in autogenous AVFs at the elbow with 1 or 2 efferent veins. Autogenous AVFs at the elbow on the radial artery have lower access flow rates than AVFs on the brachial artery.

Elbow Arteriovenous Fistulae

Multiple superficial veins in different anatomical configurations exist in the elbow. The resulting variety of elbow arteriovenous fistulae (AVFs) is described in this paper. A classification of elbow AVF in nontransposed AVF, transposed AVF and multiple outflow AVF is proposed. The nontransposed brachiocephalic AVF has the lowest primary failure rate and a good medium-term survival particularly in the elderly. The simplest technique is an end-to-side anastomosis of the median cubital vein to the brachial artery. In cases of small upper arm veins, a perforating vein AVF, using multiple outflow tracts, may be helpful to lower primary failure risk. In the era of vein mapping with portable ultrasound elbow AVF should be made when forearm veins are exhausted or too small. A side-to-side AVF in order to enhance retrograde flow in the median forearm vein seems rarely indicated, in particular considering the greater risk of steal and venous hypertension. A transposed brachiobasilic AVF is a tertiary access procedure after the simpler alternatives have been exhausted. There is conflicting evidence of the benefits of one-stage versus two-stage procedures. Therefore, the type of operation should be tailored to the individual patient.

Chronic Hemodialysis Access-Induced Distal Ischemia (HAIDI): Distinctive form of a Major Complication

Purpose

Hemodialysis access-induced distal ischemia (HAIDI) is an uncommon but potentially devastating complication. HAIDI is classified as acute, subacute and chronic based upon the time of onset. The aim of this study was to determine the prevalence, severity, patients’ characteristics and the underlying etiologic mechanism of chronic HAIDI using color Doppler ultrasonography (CDUS).

Methods

Between June and August 2010, 676 hemodialysis patients with arteriovenous access (AVA) were evaluated for clinical evidence of chronic HAIDI. In the case–control part of the study, CDUS findings were compared between ischemic patients and asymptomatic matched controls. Also, patients with chronic HAIDI were followed up until February 2014, access ligation, kidney transplantation or death.

Results

Eighteen chronic HAIDI patients were diagnosed (2.66%). Cold hand and cold sensation were the most common signs and symptoms of hand ischemia, respectively. Fifteen patients were classified in stage 1. Patients with proximal autogenous arteriovenous fistula, younger age, more previous AVAs and less access age were more likely to develop chronic HAIDI. Excessive fistula flow was found in the majority of ischemic patients (83.3%). The mean fistula flow was significantly higher in cases compared to controls (p=0.001). Eleven patients with chronic HAIDI were successfully treated by conservative measures alone until the end of follow-up ( n=3), kidney trans-plantation ( n=4) or death ( n=4).

Conclusions

CDUS is a useful adjunctive diagnostic tool to determine the etiology of chronic HAIDI. Conservative measures combined with close follow-up can be used as the first step in the management of chronic HAIDI patients with mild symptoms.

Systemic Effects of a High-Flow Arteriovenous Fistula for Hemodialysis

Purpose

Absolute treatment criteria for reducing the access volume of a high-flow access (HFA, access flow >2 L/min) are absent. Previous studies suggested that a HFA may influence the systemic circulation including blood pressure (BP) and heart rate (HR). The aim of this study was to determine these parameters after access clamping in hemodialysis patients undergoing flow-reducing access surgery.

Methods

Systolic BP (SBP), diastolic BP (DBP) and HR in HFA patients undergoing flow-reducing surgery were measured intraoperatively before and after access clamping. Data were compared to values obtained in patients receiving surgery for severe hand ischemia due to an access (HAIDI, hemodialysis access-induced distal ischemia).

Results

In 8 years, 34 patients underwent surgery for HFA (n=23) or HAIDI (n=11). Preoperative access flows in HFA were larger compared to HAIDI (3,026±147 vs 1,078±139 mL/min, respectively, p<0.001). Temporary clamping (15 sec) caused a 12±2 mm Hg increase in SBP (111±6 to 123±6 mm Hg, p<0.05) and a 6±1 mm Hg rise in DBP (57±4 to 63±5 mm Hg, p<0.05) in HFA patients. In contrast, SBP and DBP increases were not significant in HAIDI patients (+6±3 and +2±2 mm Hg, respectively, p=0.37). HR was modestly reduced in both groups following access clamping (–3±1 beats/min). The relationship between access flow volume and alterations in SBP best fitted a quadratic regression model, suggesting cardiovascular exhaustion with progressively higher access flows > 2-2.5 L/min.

Conclusions

HFA may influence systemic hemodynamics in some hemodialysis patients. The findings of this study may contribute to a tailored management of a high-flow fistula in this population.

Distal ulnar-basilic fistula as the first hemodialysis access

PURPOSE

A distal forearm ulnar-basilic (UB) arteriovenous fistula (AVF) can be chosen if a radial-cephalic (RC)-AVF is not suitable for a primary AVF. However, limited data are available on the feasibility of using a distal forearm UB-AVF as an option for primary AVF.

METHODS

This retrospective analysis included 446 patients for whom AVFs (417 RC and 29 UB) had been newly created from January 2003 to December 2009, at our hospital. Patients in whom the arterial or venous anatomy precluded RC-AVF creation, UB-AVF was established as distally as possible on the forearm. Patency, defined as access survival after creation, was calculated using Kaplan-Meier analysis. The difference in patency between the two groups was examined using log-rank test.

RESULTS

The primary patency of UB-AVFs was significantly lower than that of RC-AVFs (p=0.037, log-rank test). The primary patency rate at 1 year was 25.0% versus 44.7%, respectively. However, there was no significant difference in secondary patency between the two groups. The secondary patency rate at 1 year was 85.5% for UB-AVFs versus 82.9% for RC-AVFs. The incidence rate of percutaneous angioplasty until access abandonment per patient-years was 1.100 for UB-AVFs versus 0.671 for RC-AVFs. There was no difference in the time to maturation between the two groups.

CONCLUSIONS

The secondary patency rate of UB-AVF is similar to that of RC-AVF. We recommend the creation of an UB-AVF when an RC-AVF is not a suitable option for the primary AVF.

Creation of Autogenous Radial Cephalic Direct Wrist Access for Hemodialysis in the Elderly Using Microsurgery

Purpose

Guidelines recommend autogenous radial-cephalic AV fistula (RCAVF) as the first choice for hemodialysis. Concern has been raised that this is not suitable in the elderly. We assessed the results of microsurgery for RCAVF creation comparatively in patients older and younger than 70 years.

Methods

We prospectively followed 126 patients for three years. After systematic clinical and ultrasound assessment, a RCAVF was created using a surgical microscope. Patency was assessed immediately, at one week, one month and one year. Outcomes were recorded and stratified into two groups: <70y and >70y.

Results

RCAVF was created in 75.4% and 70.8% of the <70y and >70y groups, respectively. Incidence of early failure was 11% (<70y) and 13% (>70y). Primary and secondary patency at one year was 67% and 84% (<70y) versus 63% and 80% (>70y).

Conclusions

Microsurgery enabled the creation of RCAVF in >70y with acceptable risk of failure and slight differences by comparison with <70y. Older age should not preclude RCAVF creation.