Vascular Ultrasound for Giant Cell Arteritis: Establishing a Protocol Using Vascular Sonographers in a Fast‐Track Clinic in the United States

Abstract

Objective. We developed a fast-track clinic (FTC) to expedite the evaluation of patients suspected of having giant cell arteritis (GCA) using vascular ultrasound. Though FTCs have demonstrated efficacy in Europe, no protocolized clinic in the United States has been developed. This study introduces a new FTC model unique to the United States, using vascular sonographers, and describes the protocols used to develop reliable findings. We evaluate clinical outcomes using vascular ultrasound and temporal artery biopsy (TAB).Methods. A retrospective review included all subjects referred to the University of Washington FTC aged 50 years old or older who received both ultrasound and TAB between November 2017 and November 2019. Ultrasound was performed by a vascular sonographer trained in GCA detection. Ultrasound results were read by a vascular surgeon and reviewed by four rheumatologists certified in musculoskeletal ultrasound who had completed a course in vascular ultrasound use in GCA and large-vessel vasculitis.Results. A total of 43 subjects underwent both vascular ultrasound and TAB. Six subjects had both positive ultrasound and TAB results. There were also seven positive ultrasound results in patients with negative TAB results, most due to detection of large-vessel GCA (LV-GCA). All 29 subjects with negative ultrasound results had negative TAB results.Conclusion. This is the first study in the United States to demonstrate a reliable FTC protocol using vascular sonographers. This protocol demonstrated good agreement between ultrasound and TAB and allowed for the detection of additional cases of LV-GCA by vascular ultrasound. Vascular ultrasound improved the rate of GCA diagnosis primarily by detecting additional cases of LV-GCA.

The diagnostic accuracy of temporal artery ultrasound and temporal artery biopsy in giant cell arteritis: A single center Australian experience over 10 years

“…A recent study of 430 patients with suspected GCA found moderate agreement between sonographers (intra‐class correlation coefficient 0.61, 95% confidence interval [CI] 0.48‐0.75), similar to pathologists reporting temporal artery biopsies (0.62, 95% CI 0.49‐0.76) 10 . Fast‐track ultrasound clinics for GCA assessment in Europe, and more recently in northern America, have demonstrated promising results 11,12 …”

“… 10 Fast‐track ultrasound clinics for GCA assessment in Europe, and more recently in northern America, have demonstrated promising results. 11 , 12 …”

“…10 Fast-track ultrasound clinics for GCA assessment in Europe, and more recently in northern America, have demonstrated promising results. 11,12 Although point-of-care ultrasound is widely used in rheumatology for the assessment of inflammatory arthritis and in guiding joint aspiration and injections, [13][14][15] its use for GCA diagnosis has been limited in Australia. Ultrasound has the potential to lower healthcare costs associated with temporal artery biopsy, because the procedure usually requires day-admission in Australian hospitals where temporal artery biopsies are rarely performed in surgical rooms alone.…”

Diagnostic yield of axillary artery ultrasound in addition to temporal artery ultrasound for the diagnosis of giant cell arteritis

“…Within this context, high resolution ultrasound of the temporal arteries (tempUS), a diagnostic modality facilitating fast track approaches in order to avoid ocular ischaemic complications before treatment onset, is nowadays recommended as first line diagnostic imaging at least in European countries (7,8). In the USA, temporal artery biopsy is still considered as first line diagnostic approach, but currently efforts are undertaken on establishing sonographic imaging in the diagnostic workup of GCA (6,9). Colour duplex sonography of the axillary arteries (axUS) has been shown to detect involvement of the extracranial arteries in a considerable number of patients (10)(11)(12).…”

The Usefullness of Subclavian Artery Ultrasound Assessment in Giant Cell Arteritis Evaluation

“…This cutoff has been used in other studies, including by our group. 6 In 2011, Ghinoi et al 7 defined subclavian vasculitis as hypoechoic circumferential wall thickening ≥1.3 mm, although they noted that concerning findings <1.5 mm were rare. Recently, Ješe et al 8 determined that wall thickening ≥1.0 mm was highly sensitive and specific in their single-center prospective cohort in Slovenia, although notably the sensitivity of ultrasound in this study was very different from other ultrasound in GCA studies such as the TABUL study (98.4% vs. 54%, respectively).…”