Distal revascularization-interval ligation for limb salvage and maintenance of dialysis access in ischemic steal syndrome

Rapid progression of finger gangrene in a hemodialysis patient: A case report

Severe hemodialysis access-induced distal ischemia is an uncommon complication after arteriovenous fistula creation. Finger amputation is rare and generally does not involve the entirety of the digit. The distal revascularization interval ligation procedure has become less commonly used for hemodialysis access-induced distal ischemia over the past decade. The procedure typically requires general anesthesia, greater saphenous vein harvest, and brachial artery ligation. We describe a 64-year-old female with hypertension, diabetes mellitus, and end-stage renal disease on hemodialysis via a well-functioning brachiocephalic arteriovenous fistula who developed rapid progression of finger gangrene. She underwent the distal revascularization interval ligation procedure, followed by finger amputations. The finger amputations healed within 6 months of the distal revascularization interval ligation procedure and the fistula was preserved at 2-year follow-up.

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

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

Study of course and termination of brachial artery by dissection and computed tomography angiography methods with clinical importance

The Brachial artery is a continuation of the axillary artery, from the inferior border of the tendon of teres major to the neck of the radius, terminating into radial and ulnar arteries just a cm distal to the elbow joint. Unlike veins, variations in the arteries are comparatively less common. Anatomical variations of the brachial artery occur in almost 20% of the cases and are commonly found during routine dissection or clinical practice. To observe the variations in the course and termination of brachial artery by dissection and computed tomography (CT) angiography methods. The present study was conducted on 40 upper limbs each in the department of Anatomy & Radiology of JSS Medical College and Hospital, Mysuru. The brachial artery was traced from origin to termination and variations were noted and photographed. Patients who were undergoing CT angiography of the upper limbs in JSS Hospital were included in the study. Variations noted and compared with the dissection method. In the present study, normal patterns of the brachial arterial course and termination were observed in 31 specimens. The remaining 9 specimens showed variant course and termination in the brachial artery like an unusually tortuous superficial brachial artery, superficial brachio-ulnar artery and brachio-radial artery. CT angiography showed 6 variations and a tortuous brachial artery. A detailed description of the vascular pattern of upper limbs especially variations in their origin and termination is of extreme importance in clinical practice. The knowledge of these variations is important for catheterization, graft harvesting, arteriovenous fistula creation, shunt application and astrup examination.

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.

A modified banding technique: experience of a center

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Distal revascularization and interval ligation for dialysis access-related ischemia is best performed using arm vein conduit

OBJECTIVE

Distal revascularization and interval ligation (DRIL) is an effective approach to the management of hemodialysis access-related ischemia that offers both symptom relief and access salvage. The great saphenous vein (GSV) has been the most commonly used conduit. However, the use of an ipsilateral arm vein will allow for performance of the operation with the patient under regional anesthesia and might result in lower harvest site morbidity than the GSV. We sought to determine the suitability of DRIL using an arm vein compared with a GSV conduit.

METHODS

All patients who had undergone DRIL from 2008 to 2019 were retrospectively identified in the electronic medical records. The characteristics and outcomes of those with an arm vein vs a GSV conduit were compared using the Wilcoxon log-rank and χ² tests. Access patency was examined using Kaplan-Meier methods, with censoring at lost to follow-up or death.

RESULTS

A total of 66 patients who had undergone DRIL for hand ischemia were included in the present study. An arm vein conduit was used in 40 patients (median age, 65 years; 25% male) and a GSV conduit in 26 patients (median age, 58 years; 19% male). No significant differences in comorbidities were found between the two groups, with the exception of diabetes mellitus (arm vein group, 78%; GSV group, 50% GSV; P = .02). No difference in the ischemia stage at presentation was present between the groups, with most patients presenting with stage 3 ischemia. Also, no differences in patency of hemodialysis access after DRIL between the two groups were found (P = .96). At 12 and 24 months after DRIL, 86.9% (95% confidence interval [CI], 68.3%-94.9%) and 82.0% (95% CI, 61.3%-92.3%) of patients with an arm vein conduit had access patency compared with 93.8% (95% CI, 63.2%-99.1%) and 76.9% (95% CI, 43.0%-92.2%) of those with a GSV conduit, respectively. All but one patient had symptom resolution. The incidence of wound complications was significantly greater in the GSV group than in the arm vein group (46% vs 11%; P = .003). DRIL bypass had remained patent in all but one patient in each group, with a median follow-up of 18 months (range, 1-112 months) in the arm vein conduit group and 15 months (range, 0.25-105 months) in the GSV conduit group.

CONCLUSIONS

DRIL procedures using an arm vein have advantages over those performed with the GSV. In our series, symptom resolution and access salvage were similar but distinctly fewer wound complications had occurred in the arm vein group. Additionally, the use of an arm vein conduit avoids the need for general anesthesia. If an ipsilateral arm vein is available, it should be the conduit of choice when performing DRIL.

New Horizons in Dialysis Access: Approach to Hand Ischemia

Hand ischemia is a relatively common complication of hemodialysis arteriovenous (AV) access. Clinical manifestations frequently start with pale and cold ipsilateral hand. Symptoms can progress to pain during dialysis and can eventually lead to tissue necrosis and gangrene if not addressed in a timely fashion. Comprehensive physical examination of the hand, AV access, and comparing it with the contralateral hand will assist in differentiating hand ischemia from carpal tunnel syndrome, osteoarthritis of the hand, and others. There are several treatment options for hand ischemia based on the severity of symptoms. Conservative management with careful monitoring can be applied in early stages. However, if symptoms persist or worsen, a full arteriogram of the ipsilateral extremity should be performed to evaluate for the presence of arterial stenosis. Angioplasty of the arterial stenosis, if present, will frequently lead to the resolution of symptoms. There are several percutaneous and surgical treatment options for hand ischemia, if no arterial stenosis was found or angioplasty does not relieve symptoms. We discuss in this article these treatment options in detail. Treatment goal is to improve hand ischemia symptoms while maintaining hemodialysis AV access and preserving patient's hand. Access ligation remains a treatment of last resort.

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.

A systematic review of distal revascularization and interval ligation for the treatment of vascular access-induced ischemia

OBJECTIVE

Vascular access-induced ischemia remains a rare but significant complication of arteriovenous fistulas. Distal revascularization and interval ligation (DRIL) is one form of treatment. However, its collated efficacy through a systematic review is yet to be established.

METHODS

An electronic and systematic search of the literature in MEDLINE, Cumulative Index to Nursing and Allied Health Literature, Embase, and Cochrane Library from 1966 to 2017 in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was conducted. Quality assessment of the articles was performed using the Oxford Critical Appraisal Skills Programme, and the recommendation for practice was examined through the National Institute for Health and Care Excellence. Data of treated cases, success, time to ischemia, follow-up, age, sex, diabetes mellitus, fistula type, conduit type, and grade of ischemia were extracted and subjected to a pooled variance-weighted random-effects model.

RESULTS

Twenty-two studies (n = 459 individuals) were subjected to DRIL. Time to ischemia was 196 days (interquartile range, 30-600 days). Ischemia grade 3/4 (52%) was the most common presentation. The overall success (grades 1-4) was 81% (95% confidence interval, 80.9%-82.5%) during a mean and median follow-up of 22.2 months (interquartile range, 1-60 months) and 18 months, respectively. The conduit of choice was the great saphenous vein (n = 300/459 [65%]), and bypass thrombosis was highest in the polytetrafluoroethylene group (n = 19/44 [43%]).

CONCLUSIONS

DRIL with adequate long-term outcomes is an effective technique for the treatment of vascular access-induced ischemia.

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.

Minimally Invasive Limited Ligation Endoluminal-Assisted Revision (MILLER): A Review of the Available Literature and Brief Overview of Alternate Therapies in Dialysis Associated Steal Syndrome

Dialysis associated steal syndrome (DASS) is a relatively rare but debilitating complication of arteriovenous fistulas. While mild symptoms can be observed, if severe symptoms are left untreated, DASS can result in ulcerations and limb threatening ischemia. High-flow with resultant heart failure is another documented complication following dialysis access procedures. Historically, open surgical procedures have been the mainstay of therapy for both DASS as well as high-flow. These procedures included ligation, open surgical banding, distal revascularization-interval ligation, revascularization using distal inflow, and proximal invasion of arterial inflow. While effective, open surgical procedures and general anesthesia are preferably avoided in this high-risk population. Minimally invasive limited ligation endoluminal-assisted revision (MILLER) offers both a precise as well as a minimally invasive approach to treating both dialysis associated steal syndrome as well as high-flow with resultant heart failure. MILLER is not ideal for all DASS patients, particularly those with low-flow fistulas. We aim to briefly describe the open surgical therapies as well as review both the technical aspects of the MILLER procedure and the available literature.

Stenotic ligature: a simple technique for managing distal hypoperfusion ischemic syndrome following arteriovenous fistulas

Introduction. Distal Hypoperfusion Ischemic Syndrome (DHIS) is a multifactorial debilitating condition causing peripheral ischemia and potentially tissue necrosis. In an effort to further refine its surgical treatment we aim to describe a modified, simple and reliable technique for managing DHIS in patients with arteriovenous fistulas. Materials and Methods. Twenty-nine consecutive patients with DHIS operated by a single surgical team over a period of 7 years were included in the study. All patients underwent the same surgical technique: stenotic ligature. Outcomes were analyzed clinically and the effectiveness of the procedure was proven using McNemar test. Clinical variables were statistically analyzed in SPSS 17.0 for Windows. Results. The technique we used consists in performing a stenosing ligature on the vein, using a 0-silk suture, and adjusting the suture in order to achieve either a radial pulse or capillary pulse, while maintaining a good thrill at palpation of the vein. The procedure was successful in 83% of patients proved by immediate symptomatic relief. Paired data analysis showed significant decrease of all symptoms: cold extremity (p=0,021), paraesthesia (p less 0,001), pain (p less 0,001). History of coronary artery disease, arteriopathy or the absence of radial pulse is statistically correlated with an increased risk of developing DHIS. Conclusions. Stenotic ligature is a simple, cheap and reliable technique for managing DHIS with lower septic risks which can be easily performed under local anesthesia.

A Patient Centered Decision Making Dialysis Access Algorithm

Much controversy surrounds the establishment of proper planning, placement and management (the best practice pattern) of dialysis access. These include the dialysis type and modality selection, timing of access placement and who places the access. The lack of and the difficulty of performing randomized studies with multiple confounding factors, in an extremely heterogeneous and rapidly changing ESRD population demographics, only partly explains the dialysis access conundrum. Add to this the rapidly developing and competing technologies, the wide spectrum of the professional experience, bias and socio-economic forces to make the ESRD problems as multivariate and complex as life itself.

This overview describes a dialysis access algorithm approach to the patient needing renal replacement therapy, considering long-term improved patient outcome as the ultimate objective.

Duplex Ultrasound Evaluation for Dialysis access Selection and Maintenance: A Practical Guide

Detailed case directed history and examination is the mainstay of dialysis access modality selection, ie site and type of access, as well as for maintenance of dialysis access for longevity. As a logical step following history and physical examination, duplex ultrasound evaluation (DUE) is the most cost effective and non-invasive screening tool for evaluation for access placement and for assessment of an established access. Pre-operative vascular mapping allows selection of the optimal dialysis access modality and site. In established accesses, duplex ultrasound testing will diagnose the majority of vascular access complications and direct proper surgical or interventional radiology management. This review outlines a practical decision-making algorithm using DUE for choosing and managing the dialysis access.

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.

Proximalization of the Arterial Inflow (PAI) in Patients with Dialysis Access-Induced Ischemic Syndrome: First Report on Long-Term Clinical Results

Purpose

Proximalization of the arterial inflow (PAI) is a promising technique which was introduced several years ago as a treatment option for patients with dialysis access-induced ischemic syndrome (DAIIS). In our institutions we have been performing PAI since 2003 and have seen positive clinical results. The aim of this prospective survey is to present the long-term results of PAI.

Methods

Between 2003 and 2008, forty PAI operations were performed in our institutions: 4 patients had acute pain and sensorimotor dysfunction with no lesions, 33 had small acral lesions, and 3 had extended lesions following the creation of autogenous fistulas. In 22 cases a heparinized graft was used and in 18 cases a regular PTFE-graft. Criteria for successful treeatment of the disease course were evaluated by clinical and ultrasound examinations.

Results

In 36 cases (90%), PAI led to clinical success which was permanent in 33 patients (82%) seen in the follow-up period of 9 to 40 months. Primary patency was 62% after 12 months and secondary patency was 75% after 18 months. Heparinized grafts led to better patency rates. In 3 out of the 4 patients with large acral lesions, graft explantation was necessary due to infection or failing success.

Conclusions

Based on our experience, clinical long-term results are successful in certain patients with DAIIS. The aim for the near future should be a better patency rate to minimize the need for reoperations. In cases of extended limb necrosis/gangrene results were poor. In such patients primary closure of the access must be discussed.

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.

Prosthetic Arteriovenous Grafts for Hemodialysis

Introduction

Prosthetic arteriovenous (AV) grafts are indicated in patients with failed AV fistula (AVF), exhausted superficial veins or unsuitable vessels. Increasing the proportion of prevalent hemodialysis (HD) patients using autogenous AVF should reduce the need for AV grafts and associated morbidity. This paper reviews the current role of prosthetic AV grafts in vascular access for HD.

Technical considerations

Prior to the insertion of a prosthetic AV graft, a comprehensive review of previous access procedures and full physical examination in addition to vessel mapping is required. Anastomotic technique should take into account the flow diffuser concept, graft geometry and an anastomotic angle of 15° in order to reduce the incidence of intimal hyperplasia.

Results

Many authors report 1 and 2-yr cumulative graft patency rates of 59–90% and 50–82%, respectively. The major drawbacks with synthetic grafts include: thrombosis, a five-fold increase in infection risk and steal syndrome. The choice between surgical and percutaneous methods of dealing with blocked AV grafts remains controversial, though percutaneous techniques are assuming an increasingly important role. Percutaneous strategies are successful in declotting access in 67–95% of cases. Stenting of stenotic lesions following thrombectomy improves secondary patency rates. Strategies for dealing with AV graft infection include antibiotic prophylaxis, partial, subtotal or total graft excision and the use of biological prosthesis.

Conclusions

Though more prone to complications than autogenous AVFs, AV grafts offer a short maturation period and are more amenable to thrombectomy by radiological or surgical means. Complex AV grafts may be appropriate in patients with exhausted access sites.

Steal Syndrome of the Hemodialysis Vascular Access: Diagnosis and Treatment

Purpose

Steal syndrome is an uncommon but serious condition of arterial insufficiency distal to a permanent hemodialysis fistula. The management of the condition is a great challenge to the surgeon because of the conflicting goals of preserving the fistula and treat the ischemia. In this review the purpose was to analyze the clinical problem and treatment possibilities.

Methods

Medline and Embase databases were searched for studies relevant to diagnosis and management of steal syndrome of the hemodialysis vascular access.

Results

The diagnosis of steal syndrome is largely based on clinical features and non-invasive studies. In same cases angiography may be necessary to find out the real causes of the steal syndrome. The cause is usually high fistula flow but other causes as steal phenomenon, inflow, outflow or anastomotic stenosis have to be considered and even combination of causes. The main treatment options are some form of flow reducing procedure or the distal revascularization interval ligation method. In some cases simple distal arterial ligation is the method of choice. Furthermore, in some patients a stenosis has to be treated as the first treatment option.

Conclusion

For an appropriate treatment of a steal syndrome a careful analysis of the cause is important.

Bridge Graft to a Small Distal Artery after Fistula Ligation for Angioaccess-Induced Ischemia: Report of Two Cases

Angioaccess-induced ischemia is an infrequent but cumbersome problem, because both limb ischemia correction and access salvage should be undertaken during the same procedure. This paper reports two cases that we successfully managed with a bridge graft to a small distal artery after fistula ligation.

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.

Complications of the Arteriovenous Fistula: A Systematic Review

The implementation of patient-centered care requires an individualized approach to hemodialysis vascular access, on the basis of each patient's unique balance of risks and benefits. This systematic review aimed to summarize current literature on fistula risks, including rates of complications, to assist with patient-centered decision making. We searched Medline from 2000 to 2014 for English-language studies with prospectively captured data on ≥100 fistulas. We assessed study quality and extracted data on study design, patient characteristics, and outcomes. After screening 2292 citations, 43 articles met our inclusion criteria (61 unique cohorts; n>11,374 fistulas). Median complication rates per 1000 patient days were as follows: 0.04 aneurysms (14 unique cohorts; n=1827 fistulas), 0.11 infections (16 cohorts; n>6439 fistulas), 0.05 steal events (15 cohorts; n>2543 fistulas), 0.24 thrombotic events (26 cohorts; n=4232 fistulas), and 0.03 venous hypertensive events (1 cohort; n=350 fistulas). Risk of bias was high in many studies and event rates were variable, thus we could not present pooled results. Studies generally did not report variables associated with fistula complications, patient comorbidities, vessel characteristics, surgeon experience, or nursing cannulation skill. Overall, we found marked variability in complication rates, partly due to poor quality studies, significant heterogeneity of study populations, and inconsistent definitions. There is an urgent need to standardize reporting of methods and definitions of vascular access complications in future clinical studies to better inform patient and provider decision making.

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.

Management of Hand Ischemia in Patients with Hemodialysis Access by Distal Arterial Ligation and Revascularization

Hand ischemia due to arterial steal syndrome is an infrequent but potentially serious complication of hemodialysis access procedures. Correction of symptomatic steal syndrome typically involves fistula ligation, arterial banding, or graft lengthening, each of which provides varying degrees of success. The purpose of this study is to evaluate experience in the treatment of dialysis-associated hand ischemia by distal artery ligation and revascularization. A retrospective review was performed on 14 patients over a 6-year period who developed hand ischemia following hemodialysis access construction and underwent distal artery ligation and revascularization. Patient demographic data, operative indications, risk factors, and treatment outcome were noted. There were 10 men and four women, with a mean age of 52 years (range 21 to 73). Hand ischemia occurred in nine patients with arteriovenous grafts and five patients with arteriovenous fistulas. Nine patients developed steal syndrome within 1 month following the hemodialysis access procedure. All 14 patients underwent a surgical procedure for hand ischemia, which included ligation of the artery distal to arteriovenous fistula and arterial bypass, with reverse saphenous vein grafts in 10 patients, reversed cephalic vein grafts in three patients, and polytetrafluoroethylene graft in one patient. One patient with severe digital gangrene also required amputation. There was no perioperative morbidity or mortality. Following operation, all showed immediate improvement of the affected hand and remained free of symptoms. The cumulative patency rates of the hemodialysis access following the corrective procedure at 1, 3, and 5 years were 85.7%, 64.2%, and 42.9%, respectively. All arterial bypasses remained patent during follow-up, which ranged from 1 month to 5 years (mean 35 months). Distal arterial ligation with revascularization is an effective and durable treatment for patients with arterial steal syndrome following hemodialysis access construction. This technique can be performed with minimal morbidity and maintains a continuous access for hemodialysis.

Upper Arm Polytetrafluoroethylene Grafts for Dialysis Access. Analysis of Two Different Graft Sizes: 6 mm and 6–8 mm

The purpose of this retrospective study was to analyze 2 sizes of expanded polytetrafluoroethylene (PTFE) upper arm grafts for dialysis: 8 millimeters, tapered to 6 mm at the arterial side, and 6 millimeters. All upper arm PTFE grafts (Gore-Tex®) were performed between January 1981 and April 1997. Patient characteristics, complication rate, and patency rates were compared for both kind of grafts. Five hundred and seven PTFE grafts were analyzed (183 6-mm grafts and 324 6- to 8-mm grafts). Early failure was found in 5 grafts (2.7%) in 6-mm grafts, and in 5 grafts (1.5%) in 8-mm grafts (not significant). Steal syndrome was found in 1 patient (0.5%) of the 6-mm group, and in 11 (3.4%) of the 8-mm grafts (p=0.085). The rate of late complications requiring surgical repair was 0.56 episode per graft-year in the 6-mm grafts group, and 0.33 in the 8-mm grafts (p<0.001). Primary patency rates of 6-mm grafts were 72%, 33%, and 19% at 1, 3, and 5 years; and secondary patency rates were 86%, 68%, 56%, and 44% at 1, 3, 5, and 6 years, respectively. In the 8-mm grafts group, primary patency rates were 77%, 52%, and 39% at 1, 3, and 5 years; and secondary patency rates were 92%, 84%, 73%, and 66% at 1, 3, 5, and 6 years, respectively. Comparison of patency rates of 6-mm and 8-mm grafts were statistically significant (p< 0.001) for both primary and secondary curves. However, secondary survival curves were similar for both kind of grafts in a subpopulation of diabetic patients. The authors conclude that the 8-mm graft, tapered to 6 mm at the arterial side, is a dialysis graft with fewer complications and a better patency rate than grafts of 6 mm placed in the same anatomical position, at least in a population of nondiabetic patients. Steal syndrome was observed in some cases of diabetic and older patients with a large-bore graft. Thus, this kind of prosthesis should be avoided in this population. On the other hand, this is not a prospective, randomized study made with any intention for comparison. Therefore, the aforementioned conclusions must be cautiously considered.

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.

Plication for the Treatment of a Radio-Cephalic Fistula with Ulnar Artery Steal

Purpose

Generally the steal syndrome occurs in proximal arterial-venous fistulas and only exceptionally with distal vascular access because of the high number of arteries supplying the hand. We describe a rare case of steal syndrome of a proximalized distal radio-cephalic fistula stealing from both the radial and ulnar artery through the palmar arch.

Methods

An 86 year old man was admitted because of a cyanotic, swollen left hand with trophic lesions at the third finger. He had a latero-terminal radio-cephalic fistula performed in 2006 with subsequent proximalization performed four years later after failure of the first one. Duplex ultrasound examination showed a high flow within the fistula (2080 mL/min) and a retrograde perfusion of the radial artery from the ulnar artery through the palmar arch and an angiography excluded stenosis along the radial artery.

Results

We treated the steal syndrome through a plication technique that was performed with careful flow variations measurement, under duplex evaluation, during the surgical procedure. That procedure was effective to maintain the fistula flow and obtain the symptoms relief. The patient was evaluated the day after the intervention and after 10 weeks. The clinical examination highlighted the resolution of hand ischemia. The Duplex Ultrasound examination showed a lower flow within the fistula (1060 mL/min) and a retrograde perfusion of the radial artery from the ulnar artery through the palmar arch with a three-phase flow. Dialysis access from the fistula was never interrupted from immediately after surgery to the present date.

Conclusions

Plication is an effective technique for treatment of steal syndrome requiring a short operative time and it is related to satisfying post-operative results

Dilator-assisted Banding and Beyond: Proposing an Algorithm for Managing Dialysis Access-associated Steal Syndrome

Purpose

Dialysis access-associated steal syndrome (DASS) is a major complication of arteriovenous hemodialysis accesses. Although its underlying pathology is diverse, it is most often associated with excessive access flow. Dilator-assisted banding (DAB) is a simple flow-reduction technique that we described previously. This report is to illustrate the expansion of DAB and analyze the outcome of DAB in managing DASS.

Methods

From February 2011 to April 2015, 30 patients underwent DAB for DASS. Their relevant clinical data were retrospectively reviewed or prospectively collected, and further analyzed statistically.

Results

Of the 30 patients, 23 had an arteriogram and 3 required angioplasty ± stent placement for inflow artery stenosis. Besides intraluminal DAB (12/30), this report also included extraluminal DAB (14/30) and open fistula reduction plus DAB (4/30). After DAB, the severity scores of DASS were reduced from 2.8 ± 0.4 to 0.2 ± 0.4 for the fistula group (n = 24, p<0.001) and from 3.0 ± 0.0 to 1.2 ± 1.2 for the graft group (n = 6, p = 0.041). DAB was effective in all but two graft patients who subsequently underwent proximalization of arterial inflow (PAI) that resulted in resolution of DASS. During follow-up of 18.7 ± 14.5 months (range 1-50), all accesses remained functional. At 24-months post-DAB, the primary patency, primary-assisted patency and secondary patency rates of the fistula group were 72%, 91% and 100%, respectively.

Conclusions

DAB is a simple, effective and versatile approach for managing DASS. PAI may be employed for rescue or as primary choice when banding is ineffective. Based on our data and the literature, an algorithm is proposed for managing DASS.

An Outcomes Comparison of Native Arteriovenous Fistulae, Polytetrafluorethylene Grafts, and Cryopreserved Vein Allografts

BACKGROUND

Despite almost 2 decades of experience with cadaveric vein, there remains a paucity of available data regarding the role of cadaveric vein in hemodialysis, specifically with regard to outcomes and patency. Observations from our own experience have suggested that cadaveric vein grafts (CVGs) provide good outcomes, particularly in patients with recurrent access failure. Accordingly, this study aims to comparatively examine patency, access-related outcomes, and survival in patients undergoing placement of arteriovenous fistulae (AVF), polytetrafluorethylene (PTFE) grafts, and CVGs.

METHODS

This is a single institution 11-year retrospective case series evaluating the outcomes of 210 patients who underwent creation of AVF, PTFE grafts, and CVGs for hemodialysis access. Patients in the AVF (n = 70) and arteriovenous graft (AVG; n = 70) groups were matched to the CVG (n = 70) group by age, gender, and access location. Postoperative end points for all groups included primary and assisted patency, cause of access abandonment, and survival.

RESULTS

Patients were matched for age (P = 0.8707), gender (P = 0.6958), and access location and no significant differences existed between groups. AVF showed superior primary patency at 30 days, 1 year (64.3%, P < 0.0001) and 2 years (54.3%, P = 0.0091) in comparison to both AVG and CVG. AVG had reduced patency at 30 days (84.3%, P = 0.0009), 1 year (50.0%, P < 0.0001), and 2 years (32.9%, P = 0.0001) in comparison to AVF and CVG groups. Overall, AVF had the highest patency at all-time points followed, respectively by CVG and AVG. No significant difference existed between AVF and CVG groups with regard to secondary patency at 30 days (98.6% vs. 97.1%, P = 1.0000), 1 year (81.4% vs. 78.6%, P = 0.6749), and 2 years (68.6% vs. 51.4%, P = 0.0573). AVG patients had decreased survival (years) after access creation in comparison to AVF and CVG groups (P = 0.0003).

CONCLUSIONS

Our findings lend further support to the use of cadaveric vein for hemodialysis access surgery. As demonstrated through this comparative study, CVGs are capable of providing favorable results with regard to patency, access longevity, and patient survival. These current outcomes indicate that cadaveric vein is a sustainable alternative to PTFE for hemodialysis access surgery and should be accordingly considered for difficult access patients.

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.

Surgical Techniques for Haemodialysis Access-Induced Distal Ischaemia

Purpose

Haemodialysis access-induced distal ischaemia (HAIDI) is a significant complication of vascular access creation, and has traditionally been difficult to manage without loss of access. Current treatment options include ligation, banding, distal revascularisation with interval ligation (DRIL), proximalisation of the arterial inflow (PAI) and revision using distal flow (RUDI). The purpose of this review was to evaluate the effectiveness of the different surgical techniques in the treatment of HAIDI.

Methods

Electronic databases were searched for studies assessing surgical techniques in the treatment of HAIDI in accordance with PRISMA. The primary outcome for the study was symptomatic relief for each technique, defined within each study. Secondary outcomes included comparison of early thrombosis rates following each different procedure.

Results

Following strict inclusion/exclusion criteria by two reviewers, twenty-seven studies of surgical interventions were included and divided into subgroups for banding, DRIL, PAI and RUDI procedures. Both DRIL and banding procedures were found to have high rates of symptomatic relief. In addition, the DRIL has a significantly lower rate of early thrombosis than banding although the more recent papers seem to suggest that early thrombosis is less of a problem in banding. PAI and RUDI showed some promise but there were too few studies to be able to make any clear conclusions.

Conclusions

All four procedures have high success rate in relieving ischaemic symptoms with the DRIL procedure having a significantly better vascular access patency rate than other techniques, although further well designed studies are required to compare all four surgical techniques.

Prophylactic distal revascularization with interval ligation and simultaneous arteriovenous fistula creation in high-risk patients

Dialysis access-related ischemic steal syndrome is a well-recognized dialysis access complication. When severe, manifestations include rest pain, hand dysfunction, and tissue loss. Dialysis access attempts on the affected extremity are usually abandoned after a diagnosis of steal syndrome, and patients are often left catheter-dependent. Prophylactic distal revascularization with interval ligation has been described in patients at high-risk for steal syndrome. We present our experience with prophylactic distal revascularization with interval ligation performed simultaneously with arteriovenous fistula creation to prevent the recurrence in five patients and review the current body of literature supporting its use.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Distal revascularization and interval ligation (DRIL) procedure requires a long bypass for optimal inflow

BACKGROUND

Distal revascularization and interval ligation (DRIL) is commonly used to treat ischemic steal syndrome caused by arteriovenous hemodialysis access and has been associated with good outcomes. However, the literature lacks technical details of a successful intervention. We tested the hypothesis that a brachial-level arteriovenous fistula (AVF) generates a zone of low arterial blood pressure in the brachial artery near the AVF origin.

METHODS

We identified patients with ischemic steal syndrome caused by an AVF originating from the brachial artery level who were eligible for the DRIL procedure. All patients were studied with invasive pressure monitoring in the brachial artery at the time of digital subtraction angiography. We measured systolic, diastolic and mean arterial blood pressure at 5 cm intervals from a point in the arterial circulation 5 cm distal to the origin of the AVF and continuing proximally into the subclavian artery.

RESULTS

Our series involved 10 patients with a mean age of 66.5 (range 53-81) years. Four patients were women and 8 had diabetes. All patients had grade 3 ischemic steal syndrome with ischemic rest pain and/or ischemic tissue loss. Mean systolic, diastolic and arterial pressures increased from the level of the AVF until central pressures were reached. Systolic blood pressure was significantly lower than central blood pressure until a level 20-25 cm proximal to the AVF.

CONCLUSION

The benefits of the DRIL procedure in alleviating ischemic steal syndrome associated with hemodialysis access are best achieved with a DRIL bypass for which inflow originates at least 20-25 cm proximal to the origin of the AVF.

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.

Blood circulation in the fingers is aggravated after creating a vascular access for dialysis: assessment using skin perfusion pressure

Internal vascular shunts for haemodialysis can cause different complications. One of the most serious complications is steal syndrome, which can result in disturbed peripheral circulation causing finger necrosis and lead to amputation. Thus, prevention of these complications is important. Measurement of skin perfusion pressure (SPP) has been used in various clinical settings, including wound-healing management, and its usefulness has been increasingly unveiled. The present study was undertaken to evaluate changes in haemodynamics after internal shunt creation by measuring SPP of the thumb and the little finger before and after surgery in five patients undergoing shunt surgery using the radial artery and the cephalic vein. The study revealed average changes of -22.8 mmHg in thumb SPP. The change in the thumb was statistically significant (p < 0.05). If the effect of surgery and the threshold for wound healing are taken into account, the present results indicate the necessity to pay extra attention to fingers with extremely low preoperative SPP values. For the prevention of serious disturbances of peripheral circulation (e.g. steal syndrome), routine preoperative SPP measurement seems effective for screening of high-risk patients.

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.

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.