# Duplex ultrasound after endo revascularisation (DUSTER): protocol for a randomised controlled feasibility trial

## TL;DR

This study will test if using ultrasound scans after a blood vessel procedure improves early detection of blockages and reduces amputations in patients with poor leg blood flow.

## Contribution

The study introduces a new integrated ultrasound surveillance program to improve outcomes after endovascular therapy for limb-threatening ischaemia.

## Key findings

- The study will assess the feasibility and impact of a 1-year ultrasound surveillance program after endovascular therapy.
- It will explore patient and clinical stakeholder perspectives on ultrasound surveillance and its effect on clinical decisions.
- Results will inform future large-scale trials on the effectiveness of integrated ultrasound surveillance.

## Abstract

Endovascular therapy is the main treatment for chronic limb-threatening ischaemia in the UK. Despite a restenosis risk of 50% over 2 years, reintervention rates are low, potentially resulting in preventable amputations. European guidelines recommend ultrasound surveillance to facilitate early treatment of restenosis. This study will investigate the use of duplex ultrasound after endo revascularisation (DUSTER). The aim is to assess the feasibility, acceptability and impact on clinical decision-making of a 1-year integrated ultrasound surveillance programme after lower limb endovascular therapy.

DUSTER is a mixed-methods study. Phase I is a three-site, feasibility, open-label, randomised controlled trial. The standard of care, the control arm, is standard clinical surveillance by a vascular specialist at 1, 6 and 12 months. The intervention arm will receive integrated ultrasound (ankle-brachial pressure index, toe pressure and duplex) plus standard clinical surveillance. Primary outcomes are rates of attendance and completion of ultrasound surveillance tests, as well as the percentage of participants undergoing reintervention for restenosis. Secondary outcomes are limb salvage, amputation-free survival, reasons for amputation, complications, serious adverse events and mortality.

Phase II comprises independent semistructured interviews with intervention arm participants. The interviews will explore barriers and facilitators to ultrasound surveillance and the effect of ultrasound surveillance on patients’ lives.

Phase III has two separate focus groups for participants and clinical stakeholders to identify which outcomes matter most in any subsequent large-scale effectiveness trials.

This research has been approved by a UK (West Midlands, Black Country) Research Ethics Committee (reference 24/WM/0232) and the Health Research Authority (IRAS 349192). Dissemination of results will be by the DUSTER co-investigators in peer-reviewed journals, to the National Institute for Health and Care Research and to a lay audience via the Mid and South Essex NHS Foundations Trust website.

NCT06702306.