Time of onset in haemodialysis access-induced distal ischaemia (HAIDI) is related to the access type

Hand acceleration time (HAT) as a diagnostic tool in the assessment of haemodialysis access-induced distal ischaemia (HAIDI): study protocol for a prospective cohort study in the Barcelona south metropolitan area

INTRODUCTION

Chronic hand ischaemia may affect some haemodialysis patients with an arteriovenous fistula (AVF) or graft (AVG), a condition known as haemodialysis access-induced distal ischaemia (HAIDI). Duplex ultrasonography (DUS) can provide comprehensive insights into anatomical and perfusion properties, and measuring the hand acceleration time (HAT) has been demonstrated to be sensitive within the framework of chronic upper limb ischaemia.

METHODS AND ANALYSIS

This single-centre, prospective cohort study will involve adult end-stage renal disease (ESRD) patients requiring either AVF or AVG for haemodialysis. The primary outcome will be HAT values (measured at the radial, ulnar and four hand arteries) before and after surgery. Secondary outcomes will include the incidence of HAIDI, vascular access patency, and the incidence of complications. A sample size of 126 subjects will be required to estimate HAIDI incidence with a 95% CI and ±5% precision. Statistical analyses will involve paired t-tests to compare preoperative and postoperative HAT values and determine optimal HAT cut-off values for diagnosing HAIDI.

ETHICS AND DISSEMINATION

This study was approved by the Bellvitge University Hospital Institutional Review Board (PR 201/23). Written informed consent will be obtained from all study participants before any study-related procedure is performed. Results will be published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ClinicalTrial.gov: NCT06187207. Pre Results.

Arterial revascularization in patients with hand pain dialyzing with upper arm Arteriovenous (AV) fistulas: A single center experience

BACKGROUND

Distal hand ischemia syndrome (DHIS) is a well reported adverse outcome in patients with upper arm AV access. 25%-40% of these patients have been reported to be due to primary arterial disease complicated with significant arterial calcification. The effectiveness of revascularization of the distal arterial circulation on symptom resolution has not been reported yet.

METHODS

Retrospective single center analysis of patients evaluated for hand/forearm pain in patients with upper arm AV access who had arterial revascularization between 01/2016 and 12/2020 were included for the analysis. Fifty-one patients met inclusion criteria. Stenotic lesions greater than 70% in the subclavian, axillary, brachial, radial, or ulnar artery were treated with balloon angioplasty. Institutional approval was obtained to review charts.

OUTCOMES

Successful revascularization, improvement in pain in 48 h, 1 month, and 3 months.

RESULTS

Seventy six percent of patients had an upper arm Arteriovenous Fistula (AVF) and 24% patients had an upper arm Arteriovenous Graft (AVG). Mean access flow was 1210 (556) ml/min. 55% of patients had radial or ulnar arterial stenosis, 45% had brachial/axillary or subclavian artery stenosis. 45% patients had lesions in both radial and ulnar arteries, 88% of patients were successfully revascularized. 76% (18) of patients had improvement in symptoms within 48 h and 68% remained symptom free in 3 months. Mean DHIS stage was 3.1 before intervention and improved to 1.1 post intervention (p < 0.001). Patient satisfaction with their AV access improved from 34% to 72% (p < 0.01). Multiple regression analysis did not reveal statistically significant correlations between time on dialysis vintage and other chronic medical conditions on post procedure symptom improvement.

CONCLUSIONS

DHIS with occlusive arterial disease can be successfully revascularized to improve symptoms. Complete evaluation of the inflow arterial segment and optimal endovascular revascularization could decrease the need for access revision procedures or access abandonment.

Zero upper arm hemodialysis fistulas: utopian or realistic goal?

BACKGROUND

Although distal native fistula is the best first-line vascular access (VA), upper arm fistula (UAF) prevalence is increasing worldwide, except in Japan. Our previous survey on 50% of hemodialysis patients (HP) revealed a prevalence of UAF of less than 5%, which is lower than the findings published by the DOPPS 5 study in our country. We analyzed the VA prevalence on 100% of HPs from our department.

METHODS

In December 2021, we investigated the prevalence of vascular access of 1295 hemodialysis patients from 17 dialysis factories. VAs were classified according to location into distal forearm fistula (DFF), middle-proximal forearm fistula (MPFF), and UAF. The department manages VA using a Hub and Spoke model. The hub performs simple and complex VA including Graft placement, the Percutaneous Transluminal Angioplasty (PTA) of fistulas and central stenosis, and the surgical and endovascular rescue of thrombosed or stenotic fistulas. The spokes perform mainly simple DFFs.

RESULTS

The mean age of 1295 HP (35% females and 21% diabetics) was 69 ± 12.4 years; 506 (39%) were over 75 years old. The prevalence of DFF, MPFF, UAF, GRAFT, and CVC was 63.5%, 10.1%, 3%, 0.7%, and 22.5%, respectively. Data comparison between our two surveys revealed a lower MPFF, UAF, and GRAFT prevalence and increased CVC prevalence. Patients aged 75 years or older, women, and diabetics showed a higher frequency of CVC and a lower prevalence of DFF.

CONCLUSIONS

The findings confirm the low prevalence of UAF found in our prior survey, demonstrating that UAFs can be reduced to 5% or less, as seen in Japanese experience.

Implanted blood vessel external support device for the treatment of distal hypoperfusion ischemic syndrome in arteriovenous fistulas and high-frame-rate Vector Flow quality assessment

INTRODUCTION

Distal hypoperfusion ischemic syndrome (DHIS) is a complication occurring after arteriovenous fistula (AVF) creation. Different surgical alternatives haves been proposed in case of severe DHIS. Aim of the present paper is to present a new technique for DHIS treatment.

MATERIAL AND METHODS

Between the 1st of January 2021 and the 31st December 2021 all the patients referred to our center for DHIS grade 2-4 were treated with a new surgical technique. It consists of AVF remodeling using an external nitinol support (VasQ®) to reduce the risk of outflow vein enlargement and DHIS recurrence. To better appreciate the hemodynamic effects of the surgery, a new ultrasound technique called high-frame-rate Vector Flow (HiFR-VF) was used.

RESULTS

Seven patients (M:F 1:3; mean age 43 ± 12 years, range 29-65) were included in this study. Central line was never necessary, and technical success was 100% at 12 months. The comparison with historical data demonstrated lower recurrence of symptoms in comparison to simple artery-to-vein redo (p 0.50). The HiFR-VF showed flow with limited turbulent characteristics at the anastomosis site.

DISCUSSION AND CONCLUSION

The new technique proposed demonstrated to be safe and effective for treatment of DHIS, preventing symptoms recurrence. Ultrasound examination and HiFR-VF can be considered a valuable method to evaluate complex flows at the levels of vascular anastomosis.

Vascular Access-Related Distal Ischemia Requiring Intervention: Frequency, Risk Factors, and Consequences

BACKGROUND

Distal ischemia is a rare complication in patients undergoing placement of an arteriovenous (AV) fistula or AV graft. There are limited studies on its frequency, risk factors, clinical consequences, or feasibility of subsequent access.

METHODS

A prospective vascular access database from a large academic medical center was queried retrospectively to identify 1498 patients (mean age 56±15 years, 48% female patients, 73% Black patients) undergoing placement of at least one vascular access from 2011 to 2020. For patients who developed access-related distal ischemia requiring surgical intervention, we determined the frequency of distal ischemia, clinical risk factors, and subsequent outcomes.

RESULTS

Severe access-related distal ischemia occurred in 28 patients (1.9%; 95% confidence interval, 1.3% to 2.7%). The frequency was 0.2% for forearm AV fistulas, 0.9% for upper arm AV fistulas, 2.4% for forearm AV grafts, 2.2% for upper arm AV grafts, and 2.8% for thigh AV grafts. Risk factors independently associated with distal ischemia included female sex (odds ratio [OR], 3.64 [95% confidence interval, 1.52 to 8.72]), peripheral vascular disease (OR, 6.28 [2.84 to 13.87]), and coronary artery disease (OR, 2.37 [1.08 to 5.23]). Surgical interventions included ligation, excision, plication (banding), and other surgical procedures. Five patients developed tissue necrosis. A subsequent AV graft was placed in 13 patients, of whom only one (8%) developed distal ischemia requiring intervention.

CONCLUSIONS

Access-related distal ischemia requiring intervention was rare in this study and more common in women and patients with peripheral vascular disease or coronary artery disease. In some cases, a subsequent vascular access could be placed with a low likelihood of recurrent distal ischemia.

A Case of Ischemic Monomelic Neuropathy following Endovascular Arteriovenous Fistula Creation and Assisted Maturation

Dialysis access steal syndrome (DASS) is a phenomenon known to occur following creation of an arteriovenous fistula or arteriovenous graft. The clinical presentation of DASS is characterized by symptoms of limb ischemia due to diversion of arterial flow from the distal extremity. Ischemic monomelic neuropathy (IMN) is a rare subtype of DASS classically described as an acute, isolated presentation of peripheral neuropathy following dialysis access creation. Although the underlying pathophysiology is not entirely understood, the clinical manifestation of IMN is often described as severe distal limb pain that progresses to motor and sensory defects. The onset of IMN may occur immediately following dialysis access creation or intervention. Here, we present a case of IMN following assisted maturation of an endovascular fistula.

The intraoperative intravascular lithotripsy to recruit a calcified radial artery for creating a distal radio-cephalic fistula

Guidelines for vascular access recommend that the distal autogenous arteriovenous fistula (AVF) should be the first choice-access procedure for patients starting dialysis. Arteriosclerosis of radial artery may cause early failure, as well as failure of maturation of distal arteriovenous fistulas. To increase the incidence of distal AVFs, our team, specialized in vascular access surgery from 2004 onwards, has introduced Intraoperative Transluminal Angioplasty (ITA) under ultrasound (UG) or fluoroscopic guidance, to recruit inadequate arterials for creating distal fistulas. Intravascular lithotripsy (IL) is a novel approach to treat luminal and medial calcifications in patients with peripheral arterial disease and coronary disease. We believe that intraoperative IL may be an opportunity to recruit calcified radial arteries for creating distal radio-cephalic fistulas. Purpose of this study is to describe the intraoperative IL technical applied in our clinical experience. A 37-year-old diabetic patient with distal radio-cephalic fistula was recruited for the first IL experience. One year ago, a wrist radio-cephalic fistula was created in the right upper limb, with intraoperative UG radial artery angioplasty for extensive calcifications. The fistula was functioning but showed a delay in maturation. An angioplasty was unsuccessfully attempted to facilitate the maturation. Subsequently, a surgical revision of the fistula was performed, creating a new anastomosis immediately upstream of the previous one by performing an intraoperative IL UG of the radial artery. The fistula was immediately well functioning, and was cannulated with two needles after 1 month. It is currently being used with intradialytic adequate blood flow. The positive outcome of the case described in this paper, even if only anecdotal, could act as a trigger for further experiences with IL.

Digital pressure with laser Doppler flowmetry is better than photoplethysmography to characterize peripheral arterial disease of the upper limbs in end-stage renal disease patients

OBJECTIVE

There is no consensual definition of significant peripheral arterial disease of the upper limbs. Patients with end-stage renal disease are usually explored with Doppler ultrasound, which seems insufficient to characterize and quantify the arterial disease in this anatomic site. Candidates for haemodialysis access tend to be increasingly older and have polyvascular disease, and a better assessment of the vascular status of their upper limbs with finger systolic blood pressure is necessary. Photoplethysmography is simple and currently used in practice, but laser Doppler flowmetry may be more sensitive for low values. Our objective is to investigate additional information in the digit assessment over the ultrasound assessment of the upper limbs of patients awaiting haemodialysis and compare digital pressure values taken by photoplethysmography and laser Doppler.

METHODS

All included patients with end-stage renal disease scheduled for haemodialysis access received a prospective evaluation of their upper limbs with a clinical examination of the hands, an arterial upper limb Doppler ultrasound, and finger systolic blood pressure using photoplethysmography and laser Doppler flowmetry. Significant upper limb arterial disease was defined by a finger systolic blood pressure below 60 mm Hg or a finger brachial pressure index below 0.7.

RESULTS

Twenty-four patients were included in the study. In all, 41.7% of patients (n = 10) had parietal calcifications to the antebrachial arteries on Doppler ultrasound, 8.3% of patients (n = 2) had bilateral finger systolic blood pressure values below 60 mm Hg with laser Doppler flowmetry (but not confirmed with photoplethysmography), and 16.6% of patients (n = 4) had a finger brachial pressure index below 0.7 on both laser Doppler flowmetry and photoplethysmography. While there was an agreement between these two methods, higher values were recorded with photoplethysmography. The Pearson coefficient was 0.493 for the median of basal digital pressures in absolute values and 0.489 for finger brachial pressure index (p < 0.001).

CONCLUSION

Our study confirms the need to evaluate significant upper limb arterial disease in patients with end-stage renal disease not only with Doppler ultrasound but also with an evaluation of the finger systolic blood pressure. The correlation of the finger systolic blood pressure values using laser Doppler flowmetry and photoplethysmography was poor, which was probably due to an overestimation of the pressures with photoplethysmography. Despite the absence of a gold standard, we suggest that Laser Doppler flowmetry should be used rather than photoplethysmography to better characterize significant peripheral arterial disease of the upper limbs in patients with end-stage renal disease, particularly before creation of a new haemodialysis access. Protocol Record on clinical trial 38RC19.285.

Timing of the first cannulation and survival of arteriovenous grafts in hemodialysis patients: a multicenter retrospective cohort study

Arteriovenous graft (AVG) is an important vascular access route in hemodialysis patients. The optimal waiting time between AVG creation and the first cannulation is still undetermined, therefore the current study investigated the association between ideal timing for cannulation and AVG survival. This retrospective cohort study used data from the Taiwan National Health Insurance Database, which included 6,493 hemodialysis patients with AVGs between July 1^st 2008 and June 30^th 2012. The waiting cannulation time was defined as the time from the date of shunt creation to the first successful cannulation. Patients were categorized according to the waiting cannulation time of their AVGs as follows: ≤30 days, between 31 and 90 days, between 91 and 180 days, and >180 days. The primary outcome was functional cumulative survival, measured as the time from the first cannulation to shunt abandonment. The AVGs which were cannulated between 31 and 90 days (reference group) after construction had significantly superior functional cumulative survival compared with those cannulated ≤30 days (adjusted HR = 1.651 with 95% CI 1.482–1.839; p < 0.0001) and >180 days (adjusted HR = 1.197 with 95% CI 1.012–1.417; p = 0.0363) after construction. An analysis of the hazard ratios in patients with different demographic characteristics, revealed that the functional cumulative survival of AVGs in most groups was better when they received cannulation >30 days after construction. Consequently, in order to achieve the best long-term survival, AVGs should be cannulated at least 1 month after construction, but you should avoid waiting for >3 months.

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.

Dialysis associated steal syndromes. A narrative review

BACKGROUND

To review contemporary concepts in the genesis of Dialysis Access Steal Syndrome (DASS) and its current management.

METHODS

An electronic search of literature from 1960 to 2020 in Pubmed and the Cochrane library was conducted and practice guidelines were examined. Search terms included dialysis, steal, ischemia, access and ESRD. Clinical presentation, pathophysiology, risk factors, diagnostic techniques and management outcomes of extremity ischemia following dialysis access creation were reviewed.

RESULTS

Symptomatic steal occurs in 4-10% of patietns after creation of hemodialysis access creation. Risk factos include brachial based fistula, diabetes, female sex, coronary heart disease, cerebrovascular disease, tobacco use, age more than 60 and hypertension. Diagnosis is mainly clinical and can be aided by non invasive testing. Correction o finflow stenosis, Distal revasulatisation with interval ligation, revision using distal inflow or other techniques are useful for fistula preservation.

CONCLUSIONS

Dialysis associated steal syndromes have a complex haemodynamic causation. Clinical presentation is diagnostic; however when the diagnosis is uncertain adjunctive noninvasive perfusion tests, duplex and other imaging amy be required. Management is guided by anatomic, patient and disease-related considerations.

Does a failed DRIL mean the end for a fistula? A case report in the use of an Amplatzer plug post DRIL procedure for ongoing steal syndrome

Dialysis access steal syndrome is a well-recognised complication, affecting 1%-8% of all patients who undergo arteriovenous fistula formation particularly those that are brachial based. We present a case of ongoing steal syndrome following a DRIL procedure via retrograde flow in the ulnar artery. This was managed via a hybrid procedure and the use of an Amplatzer plug. This case demonstrates a novel use for the Amplatzer occlusion device, it is also a reminder that failure to occlude the vessel close to the fistula anastomosis can result in continued steal despite a functioning DRIL bypass.

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.

The Pre-dilatation of vessels: A simple method to recruit small caliber veins for creating distal fistulas

Maturation failure remains a major clinical problem of distal arteriovenous fistula (AVF). Early failure (EF) is associated with the small size of the veins. For about 10 years we have used in more than 1000 fistulas, the Vessels Pre-Dilatation (VPD) to increase the recruitment of small veins for creating distal AVFs. The purpose of this study is to highlight if the VPD can reduce the incidence of EF or failure to mature (FTM) in AVFs created with small veins. Data of all the consecutive patients directly admitted to our Department for their first distal AVF from January to December 2019 were collected. The patients were divided in two groups, one with a vein diameter after the tourniquet ⩽2.0 mm (G1) and one >2 mm (G2). Both in G1 then in G2 the vessels had undergone VPD. Immediate failure (IF), EF, FTM, delayed or arrested maturation rate (DAM), unassisted AVFs and matured AFVs were evaluated. The patients recruited totalled 104, 37 in G1, and 67 in G2. The two groups were homogeneous in age, incidence of diabetes, obesity, heart disease, peripheral vasculopathy, and race. Female were more numerous in G1 (51% vs 12%, p < 0.001). In G1 and G2 occurred respectively 3 IF versus zero ( p < 0.05), 10 EF (29%) versus 6 (9%) ( p < 0.05), 6 DAM (16%) versus 6 (9%), 21 unassisted AVFs (57%) versus 57 (85%) ( p < 0.01). Dividing the patients into groups of unassisted and assisted AVFs, female and low vein diameter are more represented in the assisted group. There were 32 matured AVFs (86%) in G1 and 65 (97%) in G2. In order to increase the incidence of the distal AVF, the PDV allows to include small veins. However, more patients require further interventions to achieve maturation of the fistula.

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.

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.

Two-year cumulative patency of endovascular arteriovenous fistula

BACKGROUND AND OBJECTIVES

The recent advent of a device to create a proximal radial artery arteriovenous fistula using an endovascular approach to create the anastomosis represents a significant advance in dialysis access creation. This endovascular arteriovenous fistula offers the beneficial attributes of the proximal radial artery arteriovenous fistula while adding the advantages of avoiding a surgical procedure. The endovascular arteriovenous fistula can be created safely, functions well, has excellent patency, and has a high degree of patient satisfaction. The purpose of this study is to report the 2-year cumulative patency rate for a large multicenter cohort of endovascular arteriovenous fistula cases.

DESIGN

An endovascular arteriovenous fistula was created in 105 patients using either local or regional anesthesia and conscious sedation. Patient data were obtained from each program's electronic health record system. Data collection was truncated at 2 years postprocedure and used to calculate cumulative patency. Post-access creation patient satisfaction was assessed.

RESULTS

A physiologically mature arteriovenous fistula (blood flow ⩾500 mL/min and a target vein internal diameter ⩾4 mm) was obtained in 98%. A clinically functional arteriovenous fistula (supporting two-needle dialysis according to the patient's dialysis prescription) was demonstrated in 95%. Access failure resulting in the loss of access occurred in eight cases during the study period. The cumulative patency rate at 6, 12, 18, and 24 months was 97.1%, 93.9%, 93.9%, and 92.7%, respectively. The post-procedure patient evaluation emphasized a high level of patient satisfaction.

CONCLUSION

The proximal radial artery arteriovenous fistula created using an endovascular approach for the anastomosis is associated with excellent 2-year cumulative patency and is associated with a high level of patient satisfaction.

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.

The Prognostic Significance of Puncture Timing to Survival of Arteriovenous Fistulas in Hemodialysis Patients: A Multicenter Retrospective Cohort Study

(1) Background: A functional shunt is critical to hemodialysis, but the ideal timing of shunt cannulation is still not established. In this study, we assessed the association between ideal puncture timing and shunt survival. (2) Methods: This retrospective cohort study using data from the Taiwan Health and Welfare database, which included 26885 hemodialysis patients with arteriovenous fistulas from 1 July 2008 to 30 June 2012. Fistulas were categorized by functional maturation time, defined as the time from the date of shunt construction to the first successful cannulation. Functional cumulative survival, measured as the duration from the first puncture to shunt abandonment, was mainly regarded. (3) Results: The fistulas created between 91 and 180 days prior to the first cannulation had significantly greater cumulative functional survival (HR 0.883; 95% CI 0.792–0.984), and there was no more benefit on their survival from waiting more than 180 days (HR 0.957; 95% CI 0.853–1.073) for shunt maturity. (4) Conclusions: Our results showed that to achieve better long-term shunt survivals, fistulas should be constructed at least 90 days before starting hemodialysis. Notably, there was no additional benefit on waiting more than 180 days prior to cannulation.

Pilot study using intraoperative fluorescence angiography during arteriovenous hemodialysis access surgery

INTRODUCTION:

In this pilot study, we used indocyanine green fluorescence angiography during hemodialysis access surgery. The aim was to evaluate its relevance as a diagnostic tool to visualize changes in hand microperfusion.

PATIENTS AND METHODS:

In this prospective single-center study, 47 adult patients (33 male, 14 female) with renal disease (24 preemptive, 23 endstage) were enrolled. Surgical creation of an arteriovenous fistula was performed (22 forearm, 25 upper arm). Microperfusion of the ipsilateral hand and fingers was evaluated intraoperatively using indocyanine green fluorescence angiography. We compared the cumulated microperfusion parameters ingress (In) and ingress rate (InR) before and after opening of the anastomosis. To compare the dimension of microcirculatory decline, we calculated the ratios of the parameters (RatioIn and RatioInR) after to those before anastomosis opening.

RESULTS:

The cumulated microperfusion parameters In and InR showed a significant decrease after completion of anastomosis and declamping. This effect has been seen in all patients for the hand and for each finger consecutively. During follow-up (mean 4.6, range 3-11 months), 5 patients (10.6%) complained about hemodialysis access-induced distal ischemia. The ratio of intraoperative microperfusion in those five hemodialysis access-induced ischemia patients was significantly lower compared to asymptomatic patients (RatioIn 0.23 vs 0.58, p = 0.001, and RatioInR 0.25 vs 0.62, p = 0.003).

CONCLUSION:

Intraoperative fluorescence angiography could visualize the deterioration of ipsilateral hand microperfusion after surgical creation of an arteriovenous fistula. It seems to be a promising tool to detect patients at risk for hemodialysis access-induced distal ischemia early in the peri- or even intraoperative stage.

Arteriovenous Fistula Maturation Failure in a Large Cohort of Hemodialysis Patients in the Netherlands

Objectives

Radiocephalic arteriovenous fistulas (RCAVF) are the preferred vascular access (VA) for hemodialysis (HD). Cohort studies from North America revealed that nonmaturation is a significant disadvantage of RCAVFs compared to other VAs. DESIGN: This present retrospective study describes the incidence of nonmaturation of AVFs and functional failure of arteriovenous grafts (AVG) in a multicentre cohort in the Netherlands and attempts to create a prediction model for nonmaturation of RCAVFs. Furthermore, the efficacy of interventions to promote maturation as well as the variability between hemodialysis centers was evaluated.

Materials

Medical records from 8 hospitals from 1997 to 2016 were retrospectively evaluated for VA type, maturation/primary success and demographics and comorbidities.

Methods

A prediction model was created for RCAVF nonmaturation using multivariate logistic regression analysis, selecting significant predictors using backward selection. Discrimination and calibration of the model were assessed.

Results

1383 AVFs and 273 AVGs were included in 1221 patients. Overall nonmaturation was 24% for RCAVFs, and 11% for upper arm AVFs. The functional failure rate for AVGs was 6%. The nonmaturation rate of contralateral RCAVFs after failure of an RCAVF was 22%. Procedures to improve RCAVF maturation were successful in 98/142 cases (69%). Predictors for nonmaturation were female gender, peripheral vascular disease, cerebrovascular disease and a cephalic vein diameter <2.5 mm, but the prediction model lacked sensitivity and specificity predicting individual RCAVF nonmaturation (C-statistic 0.629).

Conclusion

Nonmaturation rates are highest for RCAVFs, but nonmaturation could not be predicted with demographic parameters.

Electronic supplementary material

The online version of this article (10.1007/s00268-017-4382-z) contains supplementary material, which is available to authorized users.

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.

Graft Inclusion Technique: A New Flow Reduction Procedure for High Flow Arteriovenous Fistulae

Objective: Flow reduction is required to preserve vascular access in cases with high flow access (HFA). We report a new flow reduction procedure, the graft inclusion technique (GIT).

Methods: The GIT procedure developed by us involves the intraluminal placement and suturing of a 4-mm polytetrafluoroethylene graft to the anastomosis and outflow tract to plicate the enlarged anastomosis and maintain lower flow volumes. Flow reduction for HFA was retrospectively assessed in a series of 25 patients (age 65±12 years; 17 males and 8 females) to evaluate flow volume and patency rate, wherein 10 patients underwent conventional methods of flow reduction and 15 underwent GIT.

Results: Compared with preprocedure values, mean flow volume (MFV) was significantly lower after the procedure with both the conventional methods (1,817 vs. 586 ml/min; P<0.05) and the GIT (2,262 vs. 890 ml/min; P<0.05). An increase in MFV occurred during follow-up after conventional flow reduction (586 vs. 1,036 ml/min), while GIT could maintain lower MFV (890 vs. 791 ml/min), suggesting that GIT can significantly lower MFV levels (2,262 vs. 791 ml/min; P<0.05) and maintain these lower MFV levels during follow-up. Secondary patency rate for the GIT was 100% at 1 year and 83% at 3 years.

Conclusion: The GIT may be used as an access-preserving, reliable, long-term, and stable flow-reducing procedure that does not require flow adjustment during surgery.

Definitions and End Points for Interventional Studies for Arteriovenous Dialysis Access

This paper is part of the Clinical Trial Endpoints for Dialysis Vascular Access Project of the American Society of Nephrology Kidney Health Initiative. The purpose of this project is to promote research in vascular access by clarifying trial end points which would be best suited to inform decisions in those situations in which supportive clinical data are required. The focus of a portion of the project is directed toward arteriovenous access. There is a potential for interventional studies to be directed toward any of the events that may be associated with an arteriovenous access' evolution throughout its life cycle, which has been divided into five distinct phases. Each one of these has the potential for relatively unique problems. The first three of these correspond to three distinct stages of arteriovenous access development, each one of which has been characterized by objective direct and/or indirect criteria. These are characterized as: stage 1-patent arteriovenous access, stage 2-physiologically mature arteriovenous access, and stage 3-clinically functional arteriovenous access. Once the requirements of a stage 3-clinically functional arteriovenous access have been met, the fourth phase of its life cycle begins. This is the phase of sustained clinical use from which the arteriovenous access may move back and forth between it and the fifth phase, dysfunction. From this phase of its life cycle, the arteriovenous access requires a maintenance procedure to preserve or restore sustained clinical use. Using these definitions, clinical trial end points appropriate to the various phases that characterize the evolution of the arteriovenous access life cycle have been identified. It is anticipated that by using these definitions and potential end points, clinical trials can be designed that more closely correlate with the goals of the intervention and provide appropriate supportive data for clinical, regulatory, and coverage decisions.

[Vascular steal syndrome due to the creation of an arteriovenous shunt for hemodialysis, patient information and nephrologist responsibility]

Although responsibility is a fundamental determinant in medical practice, physicians are generally unfamiliar with its principles. The same is true for disclosure requirements and requests for compensation in the event of physical injury. We report on a representative survey of iatrogenic complications that may arise after the implementation of vascular access for haemodialysis and that illustrate's the physician's responsibility and obligation to inform the patient. Vascular access steal syndrome is a serious complication of arteriovenous fistulas, and physicians may not be sufficiently aware of the likelihood of its occurrence. Diabetes (via medial calcific sclerosis) and placement in the brachial artery (with excessively high flow rates) are the main risk factors. The precariousness of vascular status in dialysis patients threatens to increase the incidence of this complication. The therapeutic challenge is to resolve ischemic events while maintaining vascular access. The presence of gangrene of the fingers is a formal indication for surgery. The borderline between therapeutic risk (the risk inherent in a medical procedure and which cannot be controlled) and liability for injury is blurred. The French Patient's Rights Act (voted on March 4th, 2002) emphasizes the physician's duty to inform the patient of treatment-associated risks and the fact that the physician now bears the burden of proof. We suggest that a patient information sheet on the benefits and risks of vascular access should be published on the French Society of Nephrology, Dialysis and Transplantation's website.

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.

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.

Gangrene of the Hand Following a Haemodialysis Access: Lessons to be Learnt

Renal replacement therapy is a "way of life" for patients with chronic kidney disease (CKD), and haemodialysis forms their "lifeline". Haemodialysis access, via a small surgery, to anastomose an artery and a vein in the arm or forearm, is the universally accepted standard of care. However, even this minor surgical intervention can lead to devastating complications without adequate pre-operative evaluation and apt intra-operative decision making. The following article pictorically exemplifies the most dreaded complication of a gangrenous hand as well as highlights the lessons to be learnt, in order to avoid this infirmity.

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.

Access-related hand ischemia and the Hemodialysis Fistula Maturation Study

OBJECTIVE

Access-related hand ischemia (ARHI) is a major complication after hemodialysis access construction. This study was designed to prospectively describe its incidence, predictors, interventions, and associated access maturation.

METHODS

The Hemodialysis Fistula Maturation Study is a multicenter prospective cohort study designed to identify predictors of autogenous arteriovenous access (arteriovenous fistula [AVF]) maturation. Symptoms and interventions for ARHI were documented, and participants who received interventions for ARHI were compared with other participants using a nested case-control design. Associations of ARHI with clinical, ultrasound, vascular function, and vein histologic variables were each individually evaluated using conditional logistic regression; the association with maturation was assessed by relative risk, Pearson χ(2) test, and multiple logistic regression.

RESULTS

The study cohort included 602 participants with median follow-up of 2.1 years (10th-90th percentiles, 0.7-3.5 years). Mean age was 55.1 ± 13.4 (standard deviation) years; the majority were male (70%), white (47%), diabetic (59%), smokers (55%), and on dialysis (64%) and underwent an upper arm AVF (76%). Symptoms of ARHI occurred in 45 (7%) participants, and intervention was required in 26 (4%). Interventions included distal revascularization with interval ligation (13), ligation (7), banding (4), revision using distal inflow (1), and proximalization of arterial inflow (1). Interventions were performed ≤7 days after AVF creation in 4 participants (15%), between 8 and 30 days in 6 (23%), and >30 days in 16 (63%). Female gender (odds ratio, 3.17; 95% confidence interval, 1.27-7.91; P = .013), diabetes (13.62 [1.81-102.4]; P = .011), coronary artery disease (2.60 [1.03-6.58]; P = .044), higher preoperative venous capacitance (per %/10 mm Hg, 2.76 [1.07-6.52]; P = .021), and maximum venous outflow slope (per [mL/100 mL/min]/10 mm Hg, 1.13 [1.03-1.25]; P = .011) were significantly associated with interventions; a lower carotid-femoral pulse wave velocity and the outflow vein diameter in the early postoperative period (days 0-3) approached significance (P < .10). Intervention for ARHI was not associated with AVF maturation failure (unadjusted risk ratio, 1.18 [0.69-2.04], P = .56; adjusted odds ratio, 0.97 [0.41-2.31], P = .95).

CONCLUSIONS

Remedial intervention for ARHI after AVF construction is uncommon. Diabetes, female gender, capacitant outflow veins, and coronary artery disease are all associated with an increased risk of intervention. These higher risk patients should be counseled preoperatively, their operative plans should be designed to reduce the risk of hand ischemia, and they should be observed closely.

Efficacy of the Ulnar-Basilic Arteriovenous Fistula for Hemodialysis: A Systematic Review

BACKGROUND

The fistula first initiative has promoted arteriovenous fistulas (AVFs) as the vascular access of choice. To preserve as many future access options as possible, multiple guidelines advocate that the most distal AVF possible should be created in the first place. Generally, snuff box and radiocephalic (RC) are accepted and well-described sites for AVFs; however, the forearm ulnar-basilic (UB) AVF is seldom used or recommended. The aim of this study is to assess and systematically review the evidence base for the creation of the UB fistula and to critically appraise whether more attention should be given to this site.

METHODS

Electronic databases were searched for studies involving the creation of UB fistulas for dialysis in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The primary outcomes for this study were 1-year primary and secondary patency rates. Secondary outcomes were rates of hemodialysis access-induced distal ischemia (HAIDI) and infection.

RESULTS

After strict inclusion and/or exclusion criteria by 2 reviewers, 8 studies were included in our review. Weighted-pooled data reveal 1-year primary patency rate for UB AVFs of 53.0% (95% confidence interval [CI]: 40.1-65.8%) with a secondary patency rate of 72.0% (95% CI: 59.2-83.3). HAIDI and infection rates were low.

CONCLUSIONS

Our review has shown that the UB AVF may be a viable alternative when a RC AVF is not possible, and dialysis is not required urgently. It has adequate 1-year primary and secondary patency rates and extremely low risk of HAIDI. While it may be more challenging for both surgeons and dialysis nurses to make it a successful vascular access it offers a further option of distal access which may be overlooked.

Intervention for Access-Induced Ischemia: Which Option is the Best?

Introduction

Access-induced ischemia is a rare but important surgical complication with potentially devastating long-term results. The question remains which therapeutic option is the best for the different forms of ischemia.

Method

A review of the literature concerning access-induced ischemia (classification, treatment) was performed; furthermore, our own experience of more than 300 cases with ischemia was discussed.

Results

There are four different stages of dialysis access-induced ischemia syndrome (DAIIS) that need adequate treatment: stage I conservatively, stage II fistula banding, stage III proximalization operation or distal revascularization interval ligation and stage IV closure of the access.

Discussion

According to the many publications and to our own experience, there are good therapeutic options for many of the patients with DAIIS. However, in case of extended lesions/gangrene, closure of the access should be discussed in time before major amputation becomes necessary.

Digital infarction in a hemodialysis patient due to embolism from a thrombosed brachial arteriovenous fistula

Acute onset of digital ischemia and infarction is an unusual complication in patients undergoing hemodialysis. This is a report of a patient on regular hemodialysis who presented with acute distal extremity ischemia, progressing to digital infarction and on evaluation was found to have thrombosis of brachial arteriovenous fistula with embolization to the distal arteries causing digital artery occlusion.

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.

Arteriovenous fistulas and digital hypoperfusion ischemic syndrome in patients on hemodialysis

AIM: To determine survival parameters as well as characteristics of patients with this syndrome.

METHODS: The investigation was conducted over a period of eight years, as a prospective, non-randomized, clinical study which included 204 patients, treated by chronic hemodialysis. Most patients received hemodialysis 12 h per week. As vascular access for hemodialysis all subjects had an arteriovenous fistulae. Based on surveys the respondents were divided into groups of patients with and without digital hypoperfusion ischemic syndrome. Gender, demographic and anthropometric characteristics, together with comorbidity and certain habits, were recorded. During this period 34.8% patients died.

RESULTS: Patients with digital hypoperfusion ischemic syndrome were older than those without ischemia (P = 0.01). Hemodialysis treatment lasted significantly longer in the patients with digital hypoperfusion ischemic syndrome (P = 0.02). The incidence of cardiovascular disease (P < 0.001) and diabetes mellitus (P = 0.01), as well as blood flow through the arteriovenous fistula (P = 0.036), were higher in patients with digital hypoperfusion ischemic syndrome. Statistically significant differences also existed in relation to oxygen saturation (P = 0.04). Predictive parameters of survival for patients with digital hypoperfusion ischemic syndrome were: adequacy of hemodialysis (B = -3.604, P < 0.001), hypertension (B = -0.920, P = 0.018), smoking (B = -0.901, P = 0.049), diabetes mellitus (B = 1.227, P = 0.005), erythropoietin therapy (B = 1.274, P = 0.002) and hemodiafiltration (B = -1.242, P = 0.033). Kaplan-Meier survival analysis indicated that subjects with and without digital hypoperfusion ischemic syndrome differed regarding the length of survival (P < 0.001), i.e., patients with confirmed digital hypoperfusion ischemic syndrome died earlier.

CONCLUSION: Survival was significantly longer in the patients without digital hypoperfusion ischemic syndrome.

Most important chronic complications of arteriovenous fistulas for hemodialysis

The aim of this review was to highlight the most important complications of arteriovenous fistulas (AVFs) for hemodialysis (HD). The quality of vascular access for HD should be suitable for repeated puncture and allow a high blood flow rate for high-efficiency dialysis with minimal complications. The dialysis staff must be well versed in manipulation of the AVF, and there should be a minimal need for corrective interventions. Construction of an AVF creates conditions for increasing the flow of blood through the venous system. Fulfillment of these conditions reduces the risk of turbulence and endothelium injury, which, in turn, minimizes the potential for stenosis. An AVF is closest to the ideal model of vascular access. The most important complications of fistulae for HD are lymphedema, infection, aneurysm, stenosis, congestive heart failure, steal syndrome, ischemic neuropathy and thrombosis. In HD patients, the most common cause of vascular access failure is neointimal hyperplasia. It is important to gain information about early clinical symptoms of AVF dysfunction in order to prevent and adequately treat potential complications.

Side branch ligation for haemodialysis-access-induced distal ischaemia

OBJECTIVE

Chronic hand ischaemia is occasionally observed in haemodialysis patients with a brachiocephalic fistula using the Gracz technique. Open venous side branches of the access may contribute to lower peripheral perfusion pressures. This study reports on the effects of access side branch ligation (SBL) on ischaemia in patients with haemodialysis access induced distal ischaemia (HAIDI).

DESIGN, MATERIALS AND METHODS

Hand ischaemia was quantified using a published questionnaire (HIQ, minimal 0 points: no ischaemia, maximal 500: excruciating ischaemia). Finger pressures (P(dig), mmHg), digital brachial index (DBI) and access flow were measured before and after SBL.

RESULTS

Twenty-two patients were operated for grade 2-4 HAIDI during 7 years, and 12 underwent SBL (as single procedure n = 5, preceeding banding/DRIL n = 7). Hand ischaemia was attenuated after SBL only (n = 5, HIQ 216 ± 39 vs. 73 ± 26, P = 0.04). A 25% increase was observed in both P(dig) (n = 12, before SBL: 57 ± 8 mmHg, after: 72 ± 8 mmHg, P = 0.012) and DBI (before SBL: 0.49 ± 0.06, after: 0.61 ± 0.04, P = 0.006). Access flow did not change. All patients successfully resumed dialysis.

CONCLUSION

SBL may be effective as single or adjunctive surgical procedure in the treatment of HAIDI in the presence of a Gracz fistula.

Predictors of steal syndrome in hemodialysis patients

Steal syndrome is a feared complication of dialysis vascular access in a population becoming older and frailer. The aim of this study was to determine the predictor factors of steal syndrome. All proximal arteriovenous fistulas (AVFs), patent at day 30, inserted between January 2008 and December 2009 were studied. Data on age, gender, diabetes mellitus (DM) status, presence of coronary or peripheral artery disease, date of initiation of renal replacement therapy, date of access construction, localization, type of anastomosis, previous interventions, and outcome for AVF and patients were analyzed. There were 324 AVFs placed into 309 individual patients. The mean age was 66.7 ± 15.3 years, and the majority (53.7%) of the patients was male. Mean follow-up of all 324 fistulas was 18.6 ± 8.5 months. During follow-up, steal syndrome occurred in 26 (8%) of the AVFs. Univariate analysis revealed correlations between steal syndrome and DM (P = 0.002), brachiomedian fistulas (P = 0.016), and side-to-side (STS) anastomosis (P = 0.003). However, in multivariate analysis, the presence of DM, STS anastomosis, and female gender were found to be the independent risk factors. The strongest predictive factor was DM (odds ratio: 6.7; 95% confidence interval: 2.5-17.9). Being diabetic is the factor most predictive of having steal syndrome. In diabetic women, with a proximal access, it seems preferable to construct fistulas with end-to-side anastomosis to minimize the risk.

Should the arteriovenous fistula be created before starting dialysis?: a decision analytic approach

Background

An arteriovenous fistula (AVF) is considered the vascular access of choice, but uncertainty exists about the optimal time for its creation in pre-dialysis patients. The aim of this study was to determine the optimal vascular access referral strategy for stage 4 (glomerular filtration rate <30 ml/min/1.73 m²) chronic kidney disease patients using a decision analytic framework.

Methods

A Markov model was created to compare two strategies: refer all stage 4 chronic kidney disease patients for an AVF versus wait until the patient starts dialysis. Data from published observational studies were used to estimate the probabilities used in the model. A Markov cohort analysis was used to determine the optimal strategy with life expectancy and quality adjusted life expectancy as the outcomes. Sensitivity analyses, including a probabilistic sensitivity analysis, were performed using Monte Carlo simulation.

Results

The wait strategy results in a higher life expectancy (66.6 versus 65.9 months) and quality adjusted life expectancy (38.9 versus 38.5 quality adjusted life months) than immediate AVF creation. It was robust across all the parameters except at higher rates of progression and lower rates of ischemic steal syndrome.

Conclusions

Early creation of an AVF, as recommended by most guidelines, may not be the preferred strategy in all pre-dialysis patients. Further research on cost implications and patient preferences for treatment options needs to be done before recommending early AVF creation.