Understanding strategies for the treatment of ischemic steal syndrome after hemodialysis access

Arterial diameter ratio as a reliable predictor for upper limb steal syndrome in patients with arteriovenous fistula for hemodialysis

OBJECTIVES

The aim of this study is to assess the association between the anastomosis diameter enlargement and steal syndrome incidence in patients with upper limb arteriovenous fistula using ratios as reliable predictors.

MATERIAL AND METHODS

An analytical cross-sectional prospective study was conducted. A total of 49 patients with AVF hemodialysis access were recruited. Twenty-four participants with positive steal syndrome and 25 control were enrolled in the study. Anastomosis diameter, anastomosis diameter ratio, and volume flow ratio were measured ultrasonographically by two expert vascular sonographers. These clinical parameters were recorded and analyzed to assess the difference and association. Patient risk factors and steal syndrome association were emphasized.

RESULTS

The study analysis indicates a strong association in the anastomosis diameter and anastomosis diameter ratio between steal and non-steal patients with a p-value ≤0.05. Additionally, there was a significant increase in the volume flow ratio in the patients with steal syndrome compared to the control group (p-value ≤0.05). There was a strong relationship between steal syndrome and the presence of peripheral arterial disease (73.9%, p = 0.001). The ICC index of absolute agreement between the two observers was ICC= 0.99 (95% CI 0.99-0.99, n = 10), indicating excellent agreement between observers.

CONCLUSION

Anastomosis diameter and volume flow ratio strongly suggest that steal syndrome is associated with the increased diameter of anastomosis. Patients with a≥1.05 anastomosis diameter ratio have a greater risk of developing steal syndrome than those with an anastomosis ratio of ≤0.8. In addition, patients with a volume flow ratio ≥0.98 have an increased risk of developing steal syndrome than those with a volume flow ratio of ≤0.75.

Dialysis Access-Associated Steal Syndrome and Management

Dialysis-associated steal syndrome (DASS) occurs in 1-8% of hemodialysis patients with arteriovenous (AV) access. Major risk factors include use of the brachial artery for access creation, female sex, diabetes, and age > 60 years. DASS carries severe patient morbidity including tissue or limb loss if not recognized and managed promptly, as well as increased mortality. Diagnosis of DASS requires a directed history and physical exam supported by non-invasive testing. Prior to definitive therapy, detailed arteriography, fistulography, and flow measurements are performed to delineate underlying etiologies and guide management. To optimize success, DASS treatment should be individualized according to access location, underlying vascular disease, flow dynamics, and provider expertise. Possible causes of DASS include extremity inflow or outflow arterial occlusive disease, high AV access flow rate, and reversal of distal extremity arterial blood flow; DASS may also exist without any of the prior features. Depending on the DASS etiology, various endovascular and/or surgical interventions should be considered. Regardless, in the majority of patients presenting with DASS, access preservation can be achieved.

Pledgeted plication: A novel technique to treat dialysis access-related steal syndrome

Steal syndrome is a potential complication of surgically created arteriovenous fistulas that can result in sensory and/or motor deficits, or tissue loss in the affected limb. Several surgical techniques have been developed to treat steal syndrome, but all have potential drawbacks. We detail a novel, modified plication technique which involves sequential, longitudinal application of pledgets along the venous outflow to gradually narrow it, and consequently decrease flow. Its potential benefits include protection of the vein from bare suture, less turbulent flow, and thus lower risk of thrombosis. Implementation of this technique in two patients resulted in symptomatic relief and continuation of uninterrupted hemodialysis at 9- and 12-month follow-up, respectively.

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.

Proximal Arteriovenous Fistulas in Hemodialysis Patients: Advantages and Disadvantages

Introduction: The main objective of the present study is to investigate the advantages and disadvantages of proximal arteriovenous native fistulas. Hemodialysis is indispensable for patients with end-stage renal disease. For this purpose, arteriovenous fistulas (AVFs) are used. Among the native fistulas, distal radiocephalic AVF is the most preferred. However, brachiocephalic AVF (BCAVF) and brachiobasilic AVF with basilic vein transposition (basilic vein transposition arteriovenous fistula [BVTAVF]) can be used for a long time in dialysis patients whose distal vascular bed is depleted.

Methods: This is a retrospective study of 117 AVFs (BCAVF and BVTAVF), in patients with end-stage chronic renal disease, that were opened with a surgical technique (2012-2018). The postoperative two-year patency rates, AVF locations, complications, and the advantages and disadvantages of these fistulas are reviewed and recorded in the light of the literature.

Results: The mean age of the patients (52 men and 65 women) was 60.6 ± 13.6 years. The percentages of primary patency rates at 3, 6, 9, 12, and 24 months were 96.6%, 93.1%, 92%, 87.4%, and 82.8% in BCAVF patients, and 96.7%, 93.3%, 90%, 86.7%, and 80% in BVTAVF patients, respectively. The percentages of secondary patency rates at 6, 12, and 24 months were 100%, 93.3%, and 86.7% in BCAVF patients, and 100%, 100% and 87.7% in BVTAVF patients, respectively. Fistula thrombosis was seen as the most common complication. The early complication was bleeding/hematoma. As late complications, we encountered steal syndrome, ischemic pain in the relevant extremity, pseudoaneurysm, and high-output heart failure.

Conclusion: Proximal AVFs are preferable fistulas with early maturation and high primary patency rates. We believe that relatively high complications can be avoided by opening fistulas with an appropriate surgical technique.

Feasibility of a 3 mm arteriotomy for brachiocephalic fistula formation

BACKGROUND

The arteriovenous fistula is the modality of choice for long-term haemodialysis access. We describe the feasibility of routinely fashioning a brachiocephalic fistula utilising a 3 mm long arteriotomy in an attempt to reduce the incidence of symptomatic steal syndrome yet while maintaining satisfactory clinical outcomes.

METHODS

All patients who underwent brachiocephalic fistula formation using a routine 3 mm long arteriotomy within Hammersmith Hospital between January 2017 and March 2018 were included. Primary outcomes included primary failure, failure of maturation, secondary patency and steal syndrome.

RESULTS

Sixty-eight brachiocephalic arteriovenous fistula were fashioned utilising a 3 mm long arteriotomy during the study period. Mean age was 60.5 years with 59% having a history of diabetes mellitus. Mean followup was 368 days. Primary failure occurred in 10 (14.7%) patients. Cannulation was achieved in 67.3% of remaining fistula within 3-months, rising to 87.3% by 6-months. Primary patency at 6 and 12 months was 76% and 69%, respectively. Secondary patency at 6 and 12 months was 94% and 91%, respectively. Dialysis access steal syndrome was clinically apparent in three (4.4%) patients with all cases being managed conservatively.

CONCLUSION

A 3 mm long arteriotomy may be routinely utilised for brachiocephalic fistula creation in an attempt to limit the incidence of steal syndrome yet while maintaining clinical patency outcomes.

Coil Embolization of Tributaries of Brachiocephalic Fistula is Effective in the Management of Vascular Steal

BACKGROUND

To determine if an aggressive approach to occlude all or majority of the tributaries of the cephalic vein is effective in eliminating signs and symptoms of vascular steal in patients with brachiocephalic fistula.

METHODS

Retrospective chart review over a 15-month period of all patients managed with coil embolization of tributaries of brachiocephalic fistulae.

RESULTS

A total of 19 patients (11 females, age 65 ± 9.7 years), presented with signs and symptoms of vascular steal. All patients had a brachiocephalic fistula with a 6.3 month average fistula age. Overall, a total of 111 coils were used to occlude 42 tributaries. Two patients had concomitant surgical ligation of 3 tributaries. Postoperative pain at the site of coiled tributaries was reported by two patients. A single patient suffered a major postprocedure complication (delayed hypotension), requiring hospital admission. All but one patient had significant improvement in symptoms of vascular steal postintervention.

CONCLUSIONS

An aggressive approach to coil embolization of all major tributaries of a brachiocephalic fistula is effective in eliminating signs and symptoms of vascular steal.

Arterial percutaneous angioplasty in hemodialysis access: Endovascular treatment of hand ischemia

BACKGROUND

Hemodialysis access-induced distal ischemia consists of symptomatic extremity malperfusion after vascular access creation. It is usually caused by discordant vascular resistance, with arteriovenous shunting of a high blood volume from arterial into venous system and subsequent hand hypoperfusion. Less often, hemodialysis access-induced distal ischemia is caused by arterial stenosis. In these cases, access frequently has normal/low flow, radial pulse is usually absent and not recoverable with vascular access digital compression, diabetes is often present, and percutaneous transluminal angioplasty can be critical for access and limb salvage.

METHODS

Retrospective study conducted between June 2011 and February 2018 of patients with vascular access submitted to arterial percutaneous transluminal angioplasty for limb-threatening ischemia.

RESULTS

Twenty-nine patients were referred for arterial angiography after hemodialysis access-induced distal ischemia diagnosis and physical examination or ultrasound findings suggestive of arterial disease. In 11 patients, percutaneous transluminal angioplasty was not technically feasible. Among 18 treated patients, 83.3% had diabetes and 60% had skin ulcerations. Target arteries were radial (11), brachial (7), axillar (2), ulnar (2), and subclavian (1). Clinical success, defined as arteriovenous maintenance and wound healing/pain resolution, was observed in 12 patients (66.7%). Concomitant procedures included adjuvant banding (n = 2) and finger amputation (n = 1), and one reintervention was performed. No intra- or postoperative complications were reported.

CONCLUSION

Hemodialysis access-induced distal ischemia is a serious complication of hemodialysis vascular access, with multifactorial etiology. Correct and timely diagnosis is crucial for maintaining access and limb salvage. Percutaneous transluminal angioplasty is a minimally invasive procedure that may be effective and long-lasting in carefully selected patients with ischemic complaints.

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.

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.

Short interposition with a small-diameter prosthetic graft for flow reduction of a high-flow arteriovenous fistula

OBJECTIVE

The objective of this study was to evaluate the outcome of a short interposition using a small-diameter prosthetic graft as a flow-limiting procedure to manage symptomatic high-flow arteriovenous fistula (AVF).

METHODS

A retrospective review of medical records on a case series was conducted. From June 2004 to April 2017, there were 25 patients with clinical symptoms of high output cardiac failure and progressive dilation of aneurysmal fistula vein due to high-flow AVF (≥1.5 L/min) who underwent short interposition with a 5-mm prosthetic graft at Saitama Medical Center. The primary outcome was the relief of clinical symptoms; other outcome measures included technical success, surgical complications, patency of vascular access, and postoperative changes in local and systemic hemodynamics as assessed by Doppler ultrasound.

RESULTS

Twenty-five patients underwent short interposition for cardiac indications (n = 16) and aneurysmal dilation (n = 9). The technical success rate was 100%. The clinical symptoms were relieved in 24 patients (96.0%). Mean reduction in access blood flow was 52.4%. Cumulative primary unassisted patency rates (± standard error) at 1 year, 2 years, and 3 years were 76.2% ± 9.3%, 70.4% ± 10.3%, and 58.1% ± 11.6%, respectively. Secondary patency rates (± standard error) at 1 year, 2 years, and 3 years were 81.8% ± 8.2%, 71.5% ± 9.9%, and 71.5% ± 9.9%, respectively. Complications included access occlusion due to late thrombosis (n = 5 [21.7%]) and graft infection (n = 1 [4.3%]) in the median follow-up period of 3.9 years.

CONCLUSIONS

Short interposition with a prosthetic graft is a simple, effective, and durable treatment option for end-stage renal disease patients with cardiac symptoms and progressive dilation of the fistula vein due to high-flow AVF, offering clinical symptom resolution while preserving the autologous behavior of the initial access.

The Clinical Relevance and Management of High-Flow Arteriovenous Access

Obtaining an arteriovenous (AV) access for initiation of hemodialysis is considered the gold standard as it reduces risks of infections, hospitalizations, and need for interventions. It is well documented that creation of AV access can cause or aggravate heart failure. Once AV access is created, blood volume, cardiac contractility, and left ventricular end-diastolic volume increase in a nonphysiologic fashion resulting in an overall increase in cardiac output. Left ventricular hypertrophy, diastolic dysfunction, pulmonary hypertension, and high-output cardiac failure can occur. AV accesses that have blood flows greater than 1.5 L per minute are of high risk. When access flow exceeds 25% to 30% of cardiac output, the risk of developing high-output heart failure increases. Studies suggest that a blood flow (Qa)/cardiac output (CO) ratio of greater than 0.30 should be used as a screening tool to perform further cardiac testing. Depending on the severity of symptoms, management can range from banding procedure (flow reduction) or need for total abandonment of the AV access. The complications associated with high-flow AV accesses are often overlooked. Nephrologists and vascular access experts should work in tandem to mitigate potential harm to patients on dialysis who are afflicted by this condition.

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.

Operative Techniques to Prevent Dialysis Access-associated Steal Syndrome in High-risk Patients Undergoing Surgery for Hemodialysis Access: A Systematic Review

Up to 10% of patients suffer from various degrees of dialysis access-associated steal syndrome (DASS) after surgery for hemodialysis access. This systematic review was conducted to find out optimal intra-operative techniques to prevent DASS in high-risk patients.

This systematic review is registered with PROSPERO (2017:CRD42017060804). It was conducted at Department of Surgery, Aga Khan University Hospital, Karachi. All types of studies conducted on intra-operative techniques to prevent DASS in high-risk population (Age > 60 years, female gender, diabetes mellitus, peripheral arterial disease and previous DASS) undergoing access creation from January 1990 till April 2019 were included in the systematic review. Thorough search was conducted on Pubmed, Google Scholar and Cochrane databases to identify relevant articles. Included studies reviewed for success of various techniques to prevent dialysis access steal syndrome are summarized.

Out of 125 studies in the initial search, six met the inclusion criteria. Five were retrospective case series while one was a case report. The largest study sample size was 32. All but one study had arterio-venous access creation on an arm. “Proximalization of arterial inflow” was described in three and “prophylactic distal revascularization and interval ligation (DRIL) procedure” in two studies to prevent DASS. Only one patient out of these studies developed DASS at an overall follow-up of 7-42 months.

Proximalization of inflow has been reported as the most common procedure performed to prevent DASS followed by extension technique and DRIL procedure. All three procedures have satisfactory outcome with no clear superiority of one over the other.

Creating arteriovenous fistulas for children in Guatemala

OBJECTIVE

The Guatemalan Foundation for Children with Kidney Diseases was established in 2003 as the first and only comprehensive pediatric nephrology program and hemodialysis unit in Guatemala. Bridge of Life (BOL) is a not-for-profit charitable organization focused on chronic kidney disease and supplied equipment, training and support during formation of the hemodialysis unit. Pediatric permanent vascular access (VA) expertise had not been established and noncuffed dialysis catheters provided almost all VA, many through subclavian vein access sites. BOL assistance was requested for establishing a VA surgical program, resulting in recurring BOL surgical missions to create arteriovenous fistulas (AVF) in these children. This study analyzes the BOL pediatric VA missions to Guatemala.

METHODS

Three surgical pediatric VA missions were conducted in Guatemala from 2015 to 2017. Each mission was led by two or three surgeons. All supplies and equipment (including ultrasound units) were taken as part of each mission. The BOL surgical VA mission teams work with local pediatric surgeons, pediatric nephrologists, and dialysis nurses to establish collegial relationships and foster teaching interactions. We retrospectively reviewed the patient demographic data, procedures, and outcomes for these missions.

RESULTS

AVFs were created in 54 new pediatric patients. Ages were 8 to 19 years (13.4 ± 2.8 years) and 29 patients (54%) were male. Patient weights were 28 to 50 kg (30.8 ± 8.3 kg) with body mass indexes of 12 to 25 kg/m² (17.9 ± 2.9 kg/m²). Radiocephalic AVFs were created in 21 children (39%), proximal radial artery AVFs in 12 (22%). and brachial artery inflow AVFs in 5 (9%). Sixteen patients (30%) required transpositions and one a translocation; two of these were femoral procedures. Primary and cumulative patency rates were 83% and 85% at 12 months and 62% and 85% at 36 months, respectively. The median follow-up was 17 months. Interventions with fistulagram and balloon angioplasty options were not available for AVF dysfunction or access salvage during the study period. However, six patients underwent an AVF revision and salvage during subsequent missions or by one of the Guatemalan surgeons (R.S.). Four individuals underwent successful transplantation during the study period. There were no operative deaths or major complications.

CONCLUSIONS

Pediatric VA missions to Guatemala created safe and functional AVFs in concert with local pediatric surgeons and pediatric nephrologists. Three surgical missions included access operations in 54 new patients. Cumulative AVF patency was 85% at 36 months.

The efficacy of the secondary Extension Technique in the management of arterio-venous fistula-associated steal syndrome

BACKGROUND

Dialysis-associated steal syndrome remains a difficult clinical scenario for vascular access surgeons. The ideal treatment would improve blood flow to the hand without compromising the fistula; however, most treatment options rarely allow for both. The study describes an innovative technique used in clinical practice over a 17-year period for the treatment of dialysis-associated steal syndrome. The procedure and long-term results are discussed.

METHODS

27 patients with dialysis-associated steal syndrome were recruited over 17 years at two large UK University Teaching Hospitals and treated with the extension technique. All patients included were assessed for resolution of their symptoms, patency of the fistula and adequacy of needling.

RESULTS

27 patients were admitted with dialysis-associated steal syndrome and underwent surgery using the extension technique. Complete symptom resolution was seen in 26 of the 27 patients (96%), with improvements in pain, sensori-motor disturbance and temperature. All 26 patients had a patent fistula at 6-months' follow-up. At 12 months, 3 of 27 (11.1%) developed fistula thrombosis which could not be salvaged and 2 of 27 (7.4%) developed thrombosis successfully salvaged by fistulaplasty.

CONCLUSION

Our study shows that the Extension Technique is an effective treatment method for dialysis-associated steal syndrome and results have demonstrated a high level of fistula patency and a low rate of complications. It has several advantages when compared with other established treatment methods and has the versatility to be used as a method for dialysis-associated steal syndrome prevention in high-risk groups as well as treatment.

Long-term outcomes of the 'primary extension technique' in the prevention of Steal syndrome

PURPOSE

To report our 13 years of experience with the 'primary extension technique' for the prevention of dialysis-associated steal syndrome.

METHODS

All diabetic patients undergoing upper arm autogenous elbow fistula formation using the primary extension technique between September 2001 and September 2014 at a single centre were included. At follow-up all patients were evaluated for patency, adequacy of needling and the presence or absence of steal symptoms. In primary extension technique, the fistula is formed by anastomosing the median cubital vein with the proximal radial or ulnar artery just below the brachial artery bifurcation.

RESULTS

In total, 64 operations of the primary extension technique were included in this study. All patients were diabetic. Primary failure was 5%, follow-up 23-84 months. Nine patients (14%) developed cephalic vein thrombosis. In these cases, the basilic vein was successfully transposed to the existing fistula. In eight patients (12.5%), the cephalic vein required superficialisation. In three patients, the flow was preferentially into the basilic vein with poor maturation of cephalic vein. Of these three patients, there was a small proximal cephalic vein in one patient and stenosis in the other two patients. One patient who developed dialysis-associated steal syndrome is included in the results as they were listed for primary extension technique fistula formation but in fact did not have their fistula formed using primary extension technique. Instead, the anastomosis was formed proximal to the bifurcation of the brachial artery. Symptoms improved with revision of the fistula.

CONCLUSION

Our 13-year experience demonstrates that the primary extension technique is a safe and effective procedure for fistula formation. Patency rates are comparable to brachio-cephalic and brachio-basilic fistulas and primary extension technique is effective in the prevention of dialysis-associated steal syndrome.

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.

Understanding the Dialysis access Steal Syndrome. A Review of the Etiologies, Diagnosis, Prevention and Treatment Strategies

Distal hypoperfusion ischemic syndrome (DHIS), commonly referred to as hand ischemia or “steal” after dialysis access placement, occurs in 5–10% of cases when the brachial artery is used, or 10 times that of wrist arteriovenous fistulas (AVFs) using the radial artery. It is typically seen in elderly women with diabetes, and may carry severe morbidity including tissue or limb loss if not recognized and treated. Three distinct etiologies include (1) blood flow restriction to the hand from arterial occlusive disease either proximal or distal to the AV access anastomosis, (2) excess blood flow through the AV fistula conduit (true steal), and (3) lack of vascular (arterial) adaptation or collateral flow reserve (ie atherosclerosis) to the increased flow demand from the AV conduit. These three causes of steal may occur alone or in concert. The diagnosis of steal is based on an accurate history and physical examination and confirmed with tests including an arteriogram, duplex Doppler ultrasound (DDU) evaluation with finger pressures and waveform analysis. Treatment of steal includes observation of developing symptoms in mild cases. Balloon angioplasty is the appropriate intervention for an arterial stenosis. At least three distinct surgical corrective procedures exist to counteract the pathophysiology of steal. The ultimate treatment strategy depends on severity of symptoms, the extent of patient co-morbidity, and the local dialysis access technical team support and skills available.

A mechanism of banding failure in excessively dilated fistulas

Introduction:

We present an unreported cause of banding failure for flow restriction in dramatically enlarged arteriovenous fistulas (AVFs).

Case series:

Four patients operated in different institutions by two different surgeons experienced band failure within 6 months of the initially successful operation for AVF flow restriction. Prior to the initial banding procedure, each patient’s AVF was noted to have major dilatation of the post-anastomotic segment (>2 cm). All patients required a second operation for flow reduction with reconstruction of the AVF anastomosis to a tapered, smaller size. During this second procedure, the suture tie used for banding in each patient was found to have eroded a portion of the vessel wall and was extending into the fistula lumen. No thrombosis or bleeding was encountered and all AVFs have remained functional after revision.

Conclusions:

Identical findings in these four patients suggest that the extensive infolding and caliber diameter reduction created by banding these massively dilated fistulas, when combined with the pulsatility induced in the pre-banding segment, leads to a gradual incorporation of the suture tie into the vessel wall and finally within the lumen. We suggest erosion of banding material and failure of flow reduction may occur with any technique but may be more likely with a single polypropylene suture restricting very large AVF. We suggest such excessively dilated fistulas requiring flow reduction may be successfully treated by reconstruction of the AVF anastomosis to a much smaller size with tapering of the outflow vein to accommodate the revision.

Hemodynamic Impact of Anastomosis Size and Angle in Side-to-End Arteriovenous Fistulae: A Computer Analysis

Purpose

An arteriovenous fistula (AVF) is the first choice vascular access for hemodialysis. The AVF pathway can be seen as consisting of seven segments: proximal artery, distal artery, arterial collaterals, proximal vein, distal vein, venous collaterals, and the anastomosis. While most studies describe access complications without considering the impact of the anastomosis (7th segment), the present mathematical study investigated the hemodynamic impact of anastomosis size and angle on pressure drop and flow distribution.

Methods

A side-to-end AVF model was developed, consisting of an anastomosis with a given cross-sectional area (substudy 1) and angle (substudy 2). Starting from two reference cases (one for each substudy) with fixed flow distribution, pressure drop over the anastomosis was calculated for an arterial inflow in the range 600 to 1200 ml/min. The same reference cases, subsequently with fixed pressure boundary conditions, were further used to assess flow distribution over the proximal vein and distal artery.

Results

Pressure drop decreased with a larger anastomosis cross-sectional area and an angle wider than 43°, while it was almost stable for smaller angles. Although proximal arterial inflow increased for larger anastomosis areas, the overall flow distribution shifted almost totally to the proximal vein. When the anastomosis angle exceeded 58°, the proximal arterial inflow was not sufficient to deliver enough flow, leading to distal arterial flow reversal.

Conclusion

Despite the underestimation of the hemodynamic impact of the anastomosis size and angle in the literature, this study showed major influences on the pressure drop over the anastomosis and, with it, on flow distribution towards the arterial and venous outflow.

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.

[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 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.

Modified Distal Revascularization with Interval Ligation Procedure for Steal Syndrome after Arteriovenous Fistula Creation for Hemodialysis Access

Patients diagnosed with steal syndrome after hemodialysis access surgery have a few options for symptom relief while maintaining vascular access. These include fistula lengthening, banding, distal revascularization with interval ligation (DRIL), revision using distal inflow (RUDI) or proximalization of the arterial inflow (PAI). Two cases are described in which a modified DRIL procedure without interval ligation was used to relieve steal syndrome, leaving the arterial supply of an ischemic hand not entirely dependent upon a bypass. Furthermore, a review of the literature is presented in order to elucidate this relatively new treatment option as a viable means to improve hand perfusion while maintaining a functional fistula.

[Management of complications of arteriovenous fistulas for chronic hemodialysis]

La fistule artério-veineuse native est l'accès vasculaire de choix pour l'hémodialyse chronique en raison de sa longévité, son taux faible de complication et de mortalité par rapport aux pontages artério-veineux et aux cathéters. Cependant, il arrive assez souvent que l'on assiste à des complications qui sont dominées par la sténose et la thrombose. C'est une étude rétrospective des complications ayants survenues pour 31 fistules artério-veineuses pour hémodialyse chronique des 200 fistules réalisées chez 200 patients au sein du service de chirurgie vasculaire du CHU Hassan II de Fès sur une période de trois ans, étendue de Janvier 2007 à Décembre 2009. Ces complications ont été présentés par les thromboses dans 14 cas soit 45,15% de l'ensemble des complications, les sténoses dans 4 cas (12,90%,) les anévrismes dans 4 cas (12,90%), les complications ischémiques dans 3 cas (9,67%), l'infection dans 3 cas (9,67%), l'hémorragie dans 2 cas (6,45%) et l’ hyperdébit dans un seul cas soit 3,22%. On a pu conserver 22 fistules soit 70,96% par traitement chirurgical ou endovasculaire, on a confectionné une nouvelle fistule dans 8 cas soit 25,80%, et on a adressé une patiente (3,22%) pour pose d'un cathéter veineux tunnelisé permanent. Les complications des fistules artério-veineuses pour l'hémodialyse chronique sont la principale cause de morbidité chez les patients hémodialysés, il est donc important de s'impliquer lors de leur création, et de donner un maximum d'attention quand ils sont manipulés. Ceci suggère la mise en place d'un programme de surveillance de ces fistules en raison de l'impact des complications sur la morbi-mortalité du patient hémodialysé et sur le plan financier.

Radiological diagnosis of dialysis-associated complications

In daily clinical practice, the radiologist in the context of diagnosis often faces dialysis-associated complications. The complications are numerous and range from infections, catheter dysfunctions, haematomas, cardiovascular diseases, digital ischaemia, and pseudoaneurysms to shunt stenosis. In this pictorial essay, we take a close look at the imaging diagnostics of the most common complications in dialysis patients. Teaching Points • The occurrence of venous stenosis in haemodialysis patients is up to 41 %. • Catheters usually have a fibrin sheath that can be rinsed but not aspirated. • The steal phenomenon occurs in 75-90 % of patients with a shunt system. • Arterial pseudoaneurysms can cause a number of complications.

Adjuvant spinal cord stimulation improves wound healing of peripheral tissue loss due to steal syndrome of the hand: clinical challenge treating a difficult case

Hand ischaemia due to arterial steal syndrome is an infrequent, but potentially serious complication of arteriovenous fistula (AVF) for haemodialysis. We present a case of hand ischaemia caused by steal syndrome in a 69-year-old haemodialysis patient, 10 months after a brachiobasilic fistula creation. The patient underwent multiple operations without resolution of hand pain and tissue loss. The implantation of an adjuvant cervical spinal cord stimulator allowed the patient to obtain complete hand pain relief and wound healing. Probably, the diffuse microangiopathy typical of haemodialysis patients could be responsible for the persistence of ischaemic signs and symptoms after a surgical revascularisation. The effect of sympathetic blockade and the subsequent improvement of the arterial blood flow and tissue oxygenation because of spinal cord stimulation (SCS) can be useful to achieve complete ischaemic pain relief in order to enhance wound healing and to limit the tissue loss. In conclusion, the association of cervical spinal cord stimulation and surgical revascularisation could represent a valid option to treat a critical upper limb ischaemia following steal syndrome due to AVF.

Consider use of a collateral venous circuit before abandoning the arteriovenous fistula--the experience of a complex vascular access case

We describe a 65-year-old woman with diabetes on hemodialysis maintenance, with a number of complications associated with high-flow arteriovenous fistula (AVF, anastomosis between brachial artery and medial vein of the forearm) requiring an extended diagnostic and individual approach. The patient was admitted to our hospital because of pain, edema of the limb, hand ischemia, and infection caused by steal syndrome. To reduce fistula flow, banding of the proximal cephalic vein was performed. Simultaneously because of necrosis, amputation of the fifth finger was necessary. Following this procedure, the cephalic vein on the arm thrombosed. The fistula was patent through the collateral circuit, which was diagnosed in detail during the late course. A long course of antibiotics and sessions in a hyperbaric chamber allowed limb rescue. Single-needle dialysis was carried out because of problems in finding an appropriate second place. After an episode of bleeding from the puncture site caused by ulceration, we were forced to search for an alternative needling point. On the basis of ultrasound scans, an anatomic schema of the blood circuit was created. The fistula demonstrated flow from the brachial artery resulting in retrograde flow in the section of the cephalic vein distal to the anastomosis in the upper forearm. This was then seen to drain in an antegrade direction via the median vein of the forearm after the 2 vessels connected in the mid forearm. Using the diagram, 2 alternative places for needling were found and it allowed the adequate hemodialysis to be continued. Complex and complicated cases associated with native AVF could be resolved using simple diagnostic tools to preserve the fistula use for hemodialysis. Both clinical examination and ultrasound scan with the Doppler option appear to be valuable methods for finding the optimal cannulation place.

Inflow stenosis as a contributing factor in the etiology of AV access-induced ischemic steal

OBJECTIVE

To determine how frequent inflow stenosis is a contributing factor in the etiology of arteriovenous access-induced steal (AVAIS).

METHODS

A retrospective review of hemodialysis patients who underwent interventions from October 1998 to December 2011 for AVAIS was conducted at Mount Sinai Hospital. Patients with grade 3 AVAIS and complete arch and upper extremity vascular imaging were included. Demographics, access history, time to AVAIS, preoperative angiographic imaging and interventions performed were analyzed.

RESULTS

A total of 52 patients were diagnosed with grade 3 (severe) AVAIS requiring intervention over the study period. Forty-seven percent of the patients were male, average age was 62 years, 47% were of African American race and 88% were diabetic. Seventeen consecutive patients, with imaging, were included in this study. The average time to presentation of steal symptoms was 147±228 days. All of the accesses were proximal, and 65.7% were autogenous. Imaging studies consisted of angiography (14) and computed tomography angiography (3). Five patients had imaging evidence of >50% luminal inflow stenosis (29.4%). The location of stenosis was the subclavian (3 cases) and brachial (2 cases) arteries. Patients underwent distal revascularization and interval ligation (3), ligation (1) and angioplasty/stenting (1).

CONCLUSION

In our population, nearly one-third of the patients with severe AVAIS had a significant subclavian or brachial artery stenosis. The implications of this finding suggest the importance of complete preoperative imaging. The treatment of the inflow stenosis by itself may not be curative, but the correction may serve as an adjunct and contribute to the success of other therapeutic procedures.

Volume Flow Measurements in Arteriovenous Dialysis Access in Patients with and without Steal Syndrome

Introduction. Dialysis associated steal syndrome (DASS) constitutes a serious risk for patients undergoing vascular access operations. We aim to assess the measured volume flow using ultrasound in patients with clinically suspected steal syndrome and determine differences in flow among types of arteriovenous (AV) access. Methods. Patients with permanent hemodialysis access with and without ischemic steal underwent duplex ultrasound (US) exams for the assessment of volume flow and quantitative evidence of hemodynamic steal. Volume flow was measured in the proximal feeding artery. Results. 118 patients underwent US of which 82 (69.5%) had clinical evidence of steal. Women were more likely to develop steal compared to men (chi-squared test P < 0.04). Mean volume flow in patients with steal was 1542 mL/min compared to 1087 mL/min (P < 0.002) in patients without evidence of steal. A significant difference in flow volumes in patients with and without steal was only seen in patients with a brachial-cephalic upper arm AV fistula (AVF) (P < 0.002). When comparing different types of access with steal, brachial-cephalic upper arm AVFs had higher volume flows than the upper extremity AV graft (AVG) group (P = 0.04). Conclusion. In patients with DASS, women were more likely to develop steal syndrome. Significantly higher volume flows were seen with brachial-cephalic upper arm AVF in patients with steal compared to those without. A physiologic basis of this US finding may be present, which warrants further study into the dynamics of flow and its relationship to the underlying peripheral arterial pathology in the development of ischemic steal.

Prevention of vascular access hand ischemia using the axillary artery as inflow

BACKGROUND

Avoiding dialysis access-associated ischemic steal syndrome (DASS) in patients with upper extremity peripheral vascular occlusive disease while creating a functional hemodialysis vascular access may be challenging. We constructed an autogenous access with primary proximalization of the arterial inflow to prevent hand ischemia in patients at high risk for this complication.

METHODS

Patients requiring hemodialysis access with physical findings suggesting a high risk of access-related hand ischemia (absent radial, ulnar, and brachial palpable pulses associated with small calcified vessels by ultrasound examination) underwent a primary arteriovenous fistula transposition procedure utilizing the axillary artery for inflow. The arteriovenous fistula was either a reversed flow basilic vein transposition supplemented by valvulotomy (n = 22); a translocated reversed basilic vein (n = 4); a cephalic vein harvested into the forearm and placed in a loop configuration for axillary artery inflow (n = 3); or a translocated reversed saphenous vein (n = 1).

RESULTS

Thirty patients with a mean age of 60 years (range, 31-83 years) underwent successful primary axillary artery inflow procedures during a 3-year period. Of these, 23 (77%) were female and 25 (83%) were diabetic. Twenty-one (70%) had previous vascular access procedures and 10 (33%) were obese. No patient developed postoperative ischemia. Three individuals died 2, 14, and 19 months following surgery, none related to vascular access. Three accesses failed after 1, 5, and 7 months and could not be salvaged. Life-table primary, primary assisted, and cumulative patency rates were 57%, 78%, and 87% respectively at 1 year with a mean follow-up of 7 months (range, 1-25 months). Cephalic vein outflow was associated with fewer access failures, fewer interventions postoperatively, and lower rates of arm swelling (P < .01).

CONCLUSIONS

Creating a basilic vein transposition for vascular access utilizing axillary artery inflow is a good option for patients with severe peripheral vascular disease. It offers a high patency rate and the prevention of DASS. Retrograde basilic vein outflow through the median cubital and cephalic vein is associated with the best outcome and is the recommended configuration.

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.

Hemodynamic study of arteriovenous fistulas for hemodialysis access

Dialysis access failure and associated complications represent a major cause of morbidity in patients with renal failure. This is due to an incomplete understanding of the hemodynamics associated with both arteriovenous fistula (AVF) successes and complications. Several decades of research have been performed studying these complex hemodynamic changes. This review provides an overview of work undertaken in three key areas of AVF hemodynamic research: mathematical modeling, in vivo fluid dynamic measurements and in vitro fluid dynamic modeling. Current and future work is then summarized involving the application of a comprehensive, systematic study of dialysis access hemodynamics. The ultimate goal is the ability to predict clinical outcomes of dialysis access procedures through personalized, patient-specific surgical planning. If successful, this type of tool would allow surgeons to predict multiple-dialysis access intervention outcomes and choose a personalized approach to maximize success.

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.

Tratamento da síndrome de roubo de fístula arteriovenosa pela técnica de revascularização distal e ligadura arterial: relato de três casos

Fístulas arteriovenosas para hemodiálise podem apresentar complicações a longo prazo. Entre as complicações mais raras, há a isquemia distal por síndrome de roubo. Os autores relataram a experiência de três casos de pacientes portadores de fístulas braquiocefálicas, em funcionamento por longo prazo e que evoluíram com isquemia crítica do membro, sem resposta com tratamento clínico. Com o intuito de tratar esta afecção e preservar o acesso vascular, optou-se pela realização da revascularização distal interposta por ligadura arterial. Devido à raridade dos casos, relatou-se a experiência e apresentou-se uma revisão de literatura.