Digital pressure and oxygen saturation measurements in the diagnosis of chronic hemodialysis access-induced distal ischemia

Safety of bilateral arm pressure measurements in the diagnostic workup of dialysis-associated steal syndrome

OBJECTIVE

Although bilateral brachial pressure measurement is routinely included in the diagnostic work-up of upper extremity ischemia, it is generally avoided in the presence of hemodialysis access due to fears of inducing access thrombosis. This study evaluated the safety of bilateral brachial pressure measurement in patients with clinical suspicion of dialysis-associated steal syndrome (DASS).

METHODS

Patients undergoing non-invasive testing for steal syndrome between September 2015 and December 2021 were included in this study. The diagnostic workup was performed by certified vascular sonographers in an outpatient vascular lab and consisted of bilateral brachial pressures, photoplethysmography, and duplex ultrasonography of the access. Interarm differential (IAD) was defined as systolic blood pressure (SBP) in the contralateral arm minus SBP in the access arm. The primary endpoint was immediate access thrombosis.

RESULTS

The study sample consisted of 331 subjects with a mean age of 61 ± 13 and a median access age of 9 months (3-31 months) with radiocephalic fistulas present in 29%. Many patients (68%) presented with paresthesia and 4% presented with tissue loss. The mean brachial systolic pressure was 152 ± 37 mmHg on the ipsilateral arm versus 143 ± 34 mmHg on the contralateral (p-value <0.001), with an inter-arm differential (IAD) of -8.4 ± 19 mmHg. A total of 16 subjects (5%) presented a differential ⩾20 mmHg. A positive thrill was noted in all the accesses immediately following blood pressure measurement and no occurrence of access thrombosis was noted at 30 days. Proximal arterial revascularization interventions were performed in 11 cases (3%). Subjects who presented an IAD ⩾20 mmHg had lower ipsilateral digital-brachial index (0.39 ± 0.18 vs 0.68 ± 0.26; p = 0.037), a higher tendency of being referred for angiograms (37.5% vs 10.5%, p = 0.006), and more proximal arterial revascularization procedures (25.0% vs 2.2%, p = 0.001).

CONCLUSION

Bilateral arm pressure measurement in the context of dialysis access-associated steal syndrome (DASS) appears safe and useful for identifying subjects whose symptoms are due to proximal arterial inflow disease. We therefore recommend this test be considered in the diagnostic algorithms of DASS.

Influences of renal insufficiency and ischemia on mitochondrial bioenergetics and limb dysfunction in a novel murine iliac arteriovenous fistula model

Objective

Hand disability after hemodialysis access surgery has been common yet has remained poorly understood. Arteriovenous fistula (AVF) hemodynamic perturbations have not reliably correlated with the observed measures of hand function. Chronic kidney disease (CKD) is known to precipitate myopathy; however, the interactive influences of renal insufficiency and ischemia on limb outcomes have remained unknown. We hypothesized that CKD would contribute to access-related hand dysfunction via altered mitochondrial bioenergetics. Using a novel murine AVF model, we sought to characterize the skeletal muscle outcomes in mice with and without renal insufficiency.

Methods

Male, 8-week-old C57BL/6J mice were fed either an adenine-supplemented diet to induce renal insufficiency (CKD) or a casein-based control chow (CON). After 2 weeks of dietary intervention, the mice were randomly assigned to undergo iliac AVF surgery (n = 12/group) or a sham operation (n = 5/group). Measurements of aortoiliac hemodynamics, hindlimb perfusion, and hindlimb motor function were collected for 2 weeks. The mice were sacrificed on postoperative day 14 to assess skeletal muscle histopathologic features and mitochondrial function. To assess the late outcome trends, 20 additional mice had undergone CKD induction and sham (n = 5) or AVF (n = 15) surgery and followed up for 6 weeks postoperatively before sacrifice.

Results

The adenine-fed mice had had a significantly reduced glomerular filtration rate and elevated blood urea nitrogen, confirming the presence of CKD. The sham mice had a 100% survival rate and AVF cohorts an 82.1% survival rate with an 84.4% AVF patency rate. The aorta and inferior vena cava velocity measurements and the vessel diameter had increased after AVF creation (P < .0001 vs sham). The AVF groups had had a 78.4% deficit in paw perfusion compared with the contralateral limb after surgery (P < .0001 vs sham). Mitochondrial function was influenced by the presence of CKD. The respiratory capacity of the CKD-sham mice (8443 ± 1509 pmol/s/mg at maximal energy demand) was impaired compared with that of the CON-sham mice (12,870 ± 1203 pmol/s/mg; P = .0001). However, this difference was muted after AVF creation (CKD-AVF, 4478 ± 3685 pmol/s/mg; CON-AVF, 5407 ± 3582 pmol/s/mg; P = .198). The AVF cohorts had had impairments in grip strength (vs sham; P < .0001) and gait (vs sham; P = .012). However, the presence of CKD did not significantly alter the measurements of gross muscle function. The paw perfusion deficits had persisted 6 weeks postoperatively for the AVF mice (P < .0001 vs sham); however, the myopathy had resolved (grip strength, P = .092 vs sham; mitochondrial respiration, P = .108 vs sham).

Conclusions

CKD and AVF-induced distal limb ischemia both impaired skeletal muscle mitochondrial function. Renal insufficiency was associated with a baseline myopathy that was exacerbated by the acute ischemic injury resulting from AVF creation. However, ischemia was the primary driver of the observed phenotype of gross motor impairment. This model reliably reproduced the local and systemic influences that contribute to access-related hand dysfunction and provides a platform for further mechanistic and therapeutic investigation.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Ultrasound evaluation of dialysis access-related distal ischaemia

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

Dialysis associated steal syndromes. A narrative review

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Why Not Life and Limb? Vasopressor Use in Intensive Care Unit Patients the Cause of Acute Limb Ischemia

Background: Acute limb ischemia (ALI) of the upper extremity is a rare yet severe condition in intensive care unit (ICU) patients that generally leads to amputation. The aim of this study is to determine risk factors for development of upper extremity limb ischemia in ICU patients requiring vasopressor support. Methods: This is a retrospective study conducted from 2010 to 2015. Patients who received vasopressors during ICU admission were considered for the study. Patients were identified via Current Procedural Terminology (CPT) billing codes. ALI patients were matched to control patients based on diagnosis and Acute Physiology and Chronic Health Evaluation II score. Days on pressors, number of pressors, total doses, and level of ischemia were recorded. Primary end point was doses, types, and days on vasopressors. Secondary end point was level of ALI. Results: Patients in the ALI group were more likely to be started on a higher number of different types of pressors (2.6 vs 1.3 pressors). ALI patients received pressors for 8.5 days compared with 1.6 days in control patients, and received 12.8 doses compared with 3.0 doses in control patients. In addition, vasopressors with alpha-adrenergic activity were more likely to be used in the ALI group. Level of ischemia was not linked to any of the tested variables. Conclusion: Patients admitted to the ICU are more likely to sustain an acute ischemic event of an upper extremity with more vasopressor usage. Patients who received alpha-adrenergic activating vasopressors were more likely to sustain limb ischemia. When discoloration of an extremity is detected, patients should receive counteractive treatments in an effort to salvage the extremity and prevent function loss.

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

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

Digital pressure in haemodialysis patients with brachial arteriovenous fistula

Background & objectives

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

Methods

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

Results

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

Interpretation & conclusions

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

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.

Pilot study using intraoperative fluorescence angiography during arteriovenous hemodialysis access surgery

INTRODUCTION:

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

PATIENTS AND METHODS:

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

RESULTS:

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

CONCLUSION:

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

Use of the distal radial artery remnant for autogenous radial-cephalic wrist fistula after radial artery harvest for coronary artery bypass grafting

Harvesting of the radial artery is a common technique used to provide conduit for coronary artery bypass graft surgery. We report the case of a patient with exhausted left upper extremity access options, history of left upper extremity dialysis access-associated steal syndrome, and prior right radial artery harvest for coronary artery bypass graft who received an autogenous distal radial artery remnant to cephalic vein wrist fistula.

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.

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.