Differential Diagnosis for the Causes of Subclavian Steal for Patients With Vascular Access in the Forearm

Study Overview
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Brief Summary
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Subclavian steal phenomenon is normally observed in patients with stenosis of subclavian artery proximal to orifice of vertebral artery(V0). However, uremic patients undergoing hemodialysis using vascular access in the arm or forearm may also develop dialysis associated steal syndrome(DASS).For patients with symptomatic subclavian steal phenomenon, the treatment for these two groups is different. The investigators want to see if the investigators can use noninvasive duplex examination instead of invasive conventional angiography to do the differential diagnosis.

Detailed Description
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Carotid duplex is widely used for diagnosis of subclavian steal syndrome. We have a patient who suffered from acute brain stem stroke after receiving hemodialysis for months. He has DM related uremia and the vascular access is in the forearm. Subclavian steal was found on duplex in the same arm for hemodialysis. We used standard cuff test for diagnosis of subclavian steal by carotid duplex examination. Accidentally, we found the flow of subclavian artery was back to normal when the cuff is on that stops the flow. We want to see if this phenomenon can be used to serve as a differential diagnostic tool for differentiation of subclavian steal caused by stenosis of subclavian artery or due to DASS.

Official Title
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Differential Diagnosis for the Causes of Subclavian Steal for Patients With Vascular Access in the Forearm

Conditions
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Subclavian Steal

Intervention / Treatment
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* Device: carotid duplex


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patients who revealed subclavian steal in the duplex study Exclusion Criteria: patients who has vascular access in the arm instead of the forearm
Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: carotid duplex for hemolytic patients wtih SSS<br>assigned intervention:carotid duplex | Device: carotid duplex<br>* Carotid duplex in the differential diagnosis of subclavian steal syndrome due to Arteriovenous Hemodialysis access in the Ipsilateral arm<br>* Other names: steal syndrome;|
| Active Comparator: carotid duplex for nonhemolytic patients with SSS<br> | Device: carotid duplex<br>* Carotid duplex in the differential diagnosis of subclavian steal syndrome due to Arteriovenous Hemodialysis access in the Ipsilateral arm<br>* Other names: steal syndrome;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change of Subclavian Flow to Normal Flow Pattern During Cuff Test | we used carotid duplex duplex to study the change of subclavian arterial flow during cuff test to see if there is any difference between normal participants and patients under hemodialysis. There are two patterns seen. One is that the subclavian arterial flow reversed to normal flow pattern during cuff test. The other is that there is no change of subclavian flow pattern when the flow is stopped in the arm by cuff test. | two years | 
| no Change of Subclavian Arterial Flow During Cuff Test | we used carotid duplex duplex to study the change of subclavian arterial flow during cuff test to see if there is any difference between normal participants and patients under hemodialysis. There are two patterns seen. One is that the subclavian arterial flow reversed to normal flow pattern during cuff test. The other is that there is no change of subclavian flow pattern when the flow is stopped in the arm by cuff test. | one year | 
| Change of Vertebral Flow to Normal Flow Pattern During Cuff Test | we used carotid duplex duplex to study the change of vertebral arterial flow during cuff test to see if there is any difference between normal participants and patients under hemodialysis. There are two patterns seen. One is that the vertebral arterial flow reversed to normal flow pattern during cuff test. The other is that there is no change of vertebral flow pattern when the flow is stopped in the arm by cuff test. | two year | 
| no Change of Vertebral Arterial Flow During Cuff Test | we used carotid duplex duplex to study the change of vertebral arterial flow during cuff test to see if there is any difference between normal participants and patients under hemodialysis. There are two patterns seen. One is that the vertebral arterial flow reversed to normal flow pattern during cuff test. The other is that there is no change of vertebral flow pattern when the flow is stopped in the arm by cuff test. | 2 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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subclavian steal, carotid duplex, subclavian stenosis, hemodialysis with vascular access in the upper limbs, the focus of this study is to see if duplex can be used as an tool to differentiate the different causes of subclavian steal syndromes