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.