Study protocol for a prospective diagnostic accuracy study to assess the feasibility and diagnostic accuracy of serial ankle handheld Doppler waveform assessment (Ankle HHD) for surveillance after lower-limb revascularisation: WAVE study.

introductionPeripheral arterial disease (PAD) affects approximately one in five people over 60 in the UK. In severe cases, revascularisation, such as surgical bypass or endovascular methods, is often required to restore limb perfusion. Between 2000 and 2019, 527 131 revascularisation procedures were carried out in the UK. Postprocedural surveillance is essential to detect restenosis and maintain vessel patency. However, standard surveillance using duplex ultrasound (DUS) is resource intensive. Ankle Doppler waveform assessment is quick, inexpensive and accurate for PAD diagnosis, yet its role in postrevascularisation surveillance remains unexplored. This study aims to evaluate the diagnostic accuracy of ankle handheld Doppler waveform assessment (ankle HHD) for detecting restenosis after lower limb revascularisation, as compared with formal DUS. METHODS AND ANALYSIS: This is a prospective diagnostic accuracy study (ClinicalTrials.gov Identifier NCT06619223). We aim to recruit 121 people with PAD undergoing planned lower limb revascularisation at Imperial College Healthcare NHS Trust. Follow-up assessments will take place at 3 months, 6 months and 12 months post revascularisation. At each visit, a vascular scientist will perform the index test (Ankle HHD) followed by DUS as the reference standard. A subset of participants will undergo repeat testing to assess interobserver and intraobserver reliability. Restenosis will be defined as one or more arterial lesions of ≥50% stenosis or tandem lesions with a combined value of ≥50%. The primary outcome is the sensitivity of ankle Doppler waveform assessment for detecting restenosis, compared with DUS. ETHICS AND DISSEMINATION: The study has received approval from Health Research Authority (HRA) and Health and Care Research Wales (REC reference 24/LO/0462). Results will be disseminated through research presentations and papers. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov, NCT06619223.